原发性血小板增多症患者的临床及分子生物学特点研究
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摘要
研究背景：原发性血小板增多症(Essential Thrombocythemia, ET)是经典ph(Philadelphia)染色体阴性的骨髓增殖性肿瘤(Myeloproliferative Neoplasms,MPN)中最常见的亚型。血栓栓塞和出血倾向是ET最常见的并发症。传统的危险度分层将年龄≥60岁或既往血栓史列为高危组。近期国际MPN研究和治疗工作组提出了一种新的预测ET患者血栓栓塞的风险模型,即IPSET-血栓模型。
研究目的：分析中国ET患者的临床及分子生物学特点,分析其血栓形成危险因素,验证IPSET-血栓模型在中国ET患者的可行性,并评价此模型对治疗的指导意义。
研究方法：回顾性分析1982年至2012年我院诊断的ET患者(年龄≥18岁),对患者病历资料进行重新评估,所有患者均符合2008年WHO诊断标准；COX比例风险模型筛选血栓形成的独立危险因素,并用C统计值评价模型的检验效能；乘积极限法(K-M曲线)绘制并比较不同危险组的生存曲线。
研究结果：纳入患者共970例,中位随访时间为49(0-360)个月。中国ET患者临床特点与欧美患者相似。其中746例检测了JAK2V617F突变,阳性患者380例(50.9%),阴性患者366例(49.1%)。随访过程中99例(10.2%)发生血栓并发症,5年、10年及15年累积血栓发生率分别为9%、22%及35%。COX模型多因素分析表明年龄>60岁[风险比(HR)=1.949]、既往血栓史(HR=2.484)、JAK2V617F突变(HR=1.719)及心血管危险因素(HR=1.877)为血栓栓塞并发症的独立危险因素,结果与IPSET-血栓模型一致。COX模型中以上危险因素的C值为0.714(95%可信区间:0.655-0.772),高于传统分层模型的C值[0.647(95%可信区间：0.577-0.717)]。根据IPSET-血栓模型将ET患者分为低危、中危及高危组,三组无血栓生存预后有统计学差异(P<0.001)。治疗方面,在中危及高危组中,接受减低血小板治疗的患者的血栓发生率均低于组内未治疗患者(P<0.05),而在低危组患者中,差异没有统计学意义(P=0.446)。减低血小板的药物可能通过减低病程中白细胞数来达到预防血栓发生的作用。
结论：我们在中国ET患者中首次验证了IPSET-血栓模型的预后指导意义,并为IPSET-血栓模型指导治疗提供了依据。
研究背景：获得性体细胞突变JAK2V617F见于约50%-60%的原发性血小板增多症(Essential Thrombocythemia, ET)患者。近期在约50%的JAK2V617F阴性ET患者中发现了钙网蛋白基因(Calreticulin, CALR)突变,在ET诊断中有重要价值。但此突变尚未在亚洲患者中报道,且其在指导治疗方面的意义尚不明确。
研究目的：评估JAK2V617F、MPL和CALR基因突变在中国ET患者中的发生率,并探讨其在ET的诊断、判断预后及治疗中的意义。
研究方法：回顾性分析1990年至2013年我院诊断的436例ET患者的临床资料,并在所有患者中检测JAK2V617F、MPL及CALR基因突变。JAK2V617F突变采用实时定量PCR法检测,采用Sanger双向测序检测MPL基因10号外显子及CALR基因9号外显子突变,并将每种CALR基因突变亚型行TA克隆后测序。COX比例风险模型筛选血栓形成的独立危险因素,乘积极限法(K-M曲线)绘制并比较不同危险组的生存曲线。
研究结果：中国ET患者的MPL突变频率(1.4%)低于欧美ET患者,但JAK2V617F突变(55.1%)及CALR突变率(22.7%)与欧美患者相似。研究发现了5种新的CALR基因插入及缺失突变。两例患者同时存在JAK2V617F及CALR突变,其中一例CALR突变为新发现的9号外显子点突变(c.997C>T),并证实此点突变为获得性体细胞突变。与JAK2V617F突变患者相比,CALR突变患者的白细胞数、中性粒细胞数、血红蛋白含量及内源性红系集落形成(EEC)阳性率较低,而血小板数较高,差异均有统计学意义(P值均<0.01)。无JAK2/MPL/CALR突变患者的白细胞数、血红蛋白含量及EEC阳性率均介于JAK2V617F突变及CALR突变患者之间。Cox模型多因素分析显示JAK2V617F突变是诊断时(HR=1.836,P=0.040)及随访过程中(HR=2.678,P=0.023)血栓形成的独立危险因素,而CALR基因突变并不是血栓危险因素。K-M曲线显示CALR突变患者的无血栓生存率高于JAK2V617F突变患者(P=0.014),这种差异可能与Ⅱ型CALR突变患者的血栓发生率(7.9%)显著低于JAK2V617F突变患者(30.0%)有关(P=0.004)。JAK2V617F突变患者的骨纤转化率与CALR突变患者无显著差异(P=1.000),但CALR突变患者的骨髓网状纤维沉积分级高于JAK2V617F突变患者(P=0.003),这种现象主要由于I型CALR突变患者中I级网状纤维增高引起。在同一患者接受减低血小板治疗前与治疗后的配对样本中分别检测CALR基因突变,发现减低血小板治疗并不能完全消除CALR突变克隆。联合应用抗血小板及减低血小板的治疗降低了JAK2V617F患者的血栓发生率(P=0.034),但未减少CALR突变患者的血栓发生(P=1.000)。
结论：我们在中国ET患者中证实了CALR基因突变在ET的诊断和判断预后中的价值,并发现JAK2V617F和CALR基因突变与临床特点及预后有关。本研究为基于分子生物学指标的治疗策略提供了初步依据。
研究背景：儿童原发性血小板增多症(essential thrombocythemia,ET)罕见,由于样本量小,临床特点并未完全明确,因此需要较大样本量研究来评估。
研究目的：评价儿童ET患者的症状特点、血栓出血并发症、疾病转化率及治疗策略。
研究方法：回顾性分析1986年至2012年于我院诊断为ET的70例儿童患者(年龄≤18岁),对患者的临床特点和实验室检查进行分析。
研究结果：中位诊断年龄为12(2-18)岁,伴有明显的男性倾向(男/女=1.4)与成人ET的女性倾向不同。多数患儿(54.3%)就诊时无血小板增多相关症状,有无临床症状与血小板数有关(P=0.002)。儿童ET的JAK2V617F阳性率(18.8%)低于成人ET。与成人不同的是,JAK2V617F突变阳性与阴性患儿的白细胞数、中性粒细胞数、血红蛋白水平及血小板数无显著差异(P均>0.05)。多数患儿(82.6%)的血小板增多相关症状可通过药物缓解。儿童ET患者使用羟基脲也存在耐药或不耐受,但长期使用未发现严重副作用,无一例继发其它恶性肿瘤。ET患儿的血栓发生率低(2.9%)于成人ET,且2例血栓患儿均为女性,其中一例为腹腔静脉血栓导致门静脉海绵样变并合并骨髓纤维化,在儿童ET中是首次报道。与成人ET一样,儿童ET转化为骨髓纤维化的比例较低(2.9%),病程中白细胞数持续升高可能是骨纤转化的前兆。
结论：儿童ET在临床转归及分子生物学特点上不同于成人ET。
研究背景：儿童原发性血小板增多症(Essential Thrombocythemia,ET)的JAK2V617F阳性率低于成人患者,多数未发现分子克隆标志,发病机制仍不清楚。
研究目的：检测儿童ET的突变位点并推测克隆演变,为揭示儿童ET的发病机制提供依据。
研究方法：采用高通量目标区域捕获测序技术在20例儿童ET患者中检测与血液肿瘤相关的55个基因突变并进行验证,验证为真阳性的所有位点在100个正常人中检测排除多态性位点。根据基因突变负荷预测克隆演变过程。
研究结果：平均测序深度为384×,平均可覆盖靶区域的99.6%,验证结果显示准确率达93.8%。最终确定16种疾病相关点突变,这些突变在100个正常人DNA样本中均未发现。共涉及突变基因11个,累及患者13例,其余7例患儿未发现疾病相关基因突变。与成人不同的是,经自身正常组织对照证实多数突变位点(56.3%)为生殖细胞突变,可能是儿童ET发病提早的重要机制之一。JAK2V617F阳性患者6例,阳性率(18.8%)低于成人ET。所有20例患儿均未发现CALR基因和MPL基因突变。JAK246/1单体型基因型显示,12例为(60%)CG杂合子,8例(40%)为CC纯合子,无GG纯合子。多种基因可以和JAK2V617F同时发生,包括ASXL1、U2AF1、NRAS和IDH1。突变基因涉及多种功能,其中JAK-STAT信号转导通路基因(45%)与表观调节基因(25%)最常累及,两类基因可合并突变(20%)。基于突变负荷的克隆性分析显示JAK2V617F突变可能是发生于表观调节基因突变后的晚期事件。
结论：儿童ET的突变谱不同于成人,JAK2V617F突变率低,且无CALR突变,可能存在与成人不同的发病机制。生殖细胞突变可能在儿童ET提前发病机制中起重要作用。JAK2V617F可能并不是驱动基因,而是其它基因突变累积到一定程度的继发改变。
Background:Essential thrombocythemia (ET) is the most common type of Philadelphia chromosome negative myeloproliferative neoplasms characterized by increased risk of vascular events (thrombosis and hemorrhage). Traditionally, advanced age≥60and history of thrombosis are regarded as predictive risk factors for thrombosis. Recently, a new International Prognostic Score of thrombosis for ET (IPSET-thrombosis) was proposed to predict thrombotic events.
Objectives:To analyze clinical and biological characteristics of ET, and to evaluate the prognostic value and clinical implication of the IPSET-thrombosis model in a large cohort of Chinese ET patients.
Methods:We retrospectively evaluated the characteristics and risk factors for thrombosis in Chinese patients diagnosed with ET in our hospital from1982to2012. Their clinical data were carefully reassessed, and all of them met the2008WHO criteria. Cox proportional hazards regression was employed to carry out univariate survival analysis, and factors that were significant were forced to multivariate survival analysis. The C-index was calculated based on Receiver Operating Characteristic curve using prognostic index. Thrombosis-free survival was estimated by Kaplan-Meier method, and log-rank test was used to compare thrombosis-free survival data.
Results:A total of970ET patients were enrolled. The median follow-up was49months (range,0-360). Chinese ET patients had similar clinical characteristics as Caucasian patients. JAK2V617F mutation was investigated in746patients among whom380(50.9%) were positive. During follow-up,99(10.2%) patients experienced at least one major thrombotic event. The5-,10-, and15-yr cumulative rates of thrombotic events were9.0%,22.0%, and35.0%, respectively. Similar to the IPSET-thrombosis study, our multivariate analysis revealed age>60(HR=1.949), previous thrombosis (HR=2.484), JAK2V617F mutation (HR=1.719), and cardiovascular risk factors (HR=1.877) as independent risk factors for thrombosis. We confirmed that the above risk factors in IPSET-thrombosis, when compared with traditional risk factors (e.g., age≥60and previous thrombotic events), were more predictive of thrombotic events (C-index0.714vs.0.647). Classification by IPSET-thrombosis risk groups revealed different cumulative thrombosis-free survival (P<0.001). For treatment, patients in the intermediate-and high-risk group derived clinical benefit from cytoreductive agents (P<0.05), but those in the low-risk group did not (P=0.446). The lower risk of thrombosis on cytoreductive therapy was related to decrease in leukocyte count during the disease course.
Conclusions:We validate the reproducibility of IPSET-thrombosis in Chinese ET patients and provide key clinical implications.
Background:Somatic JAK2V617F mutation exists in about50-60%of patients with essential thrombocythemia (ET). Recently, discovery of calreticulin (CALR) mutations, which were found in about half of ET patients with wild type JAK2, fills the molecular diagnostic gap. However, the prevalence of CALR mutations has not been reported in Asian patients, and its therapeutic implications have not yet been evaluated.
Objectives:We studied profiles of specific mutations in Chinese ET patients to provided additional details on the utility of CALR mutations in the diagnosis, prognosis and treatment of ET.
Methods:We retrospectively evaluated the clinical characteristics in436Chinese patients diagnosed with ET in our hospital from1990to2013. Mutations in JAK2V617F, MPL exon10and CALR exon9were analyzed in all of the patients. Real-time quantitative PCR assay was performed to detect JAK2V617F mutation. Mutations in CALR and MPL were assessed by bidirectional sequencing. Each type of deletions or insertions in CALR was cloned by the TA cloning system. Cox proportional hazards regression was employed to carry out univariate survival analysis, and factors that were significant were forced to multivariate survival analysis. Thrombosis-free survival was estimated by Kaplan-Meier method, and log-rank test was used to compare thrombosis-free survival data.
Results:Compared with Caucasian patients, Chinese patients had a lower frequency of MPL mutations (1.4%) but comparable JAK2V617F (55.1%) and CALR mutations (22.7%). We found5new types of deletions or insertions in CALR. Two patients harbored both JAK2V617F and CALR mutations; one of whom had a novel point mutation in CALR exon9(c.997C>T). Absence of the point mutation in T cells confirmed the mutation to be somatic. Compared with V617F+patients, CALR-mutated patients displayed lower leukocyte count, granulocyte count, hemoglobin level, lower rate of positive EECs but higher platelet count (P<0.01for each comparison). Triple-negative patients had intermediate leukocyte count, hemoglobin level, platelet count and intermediate rate of positive EECs between V617F+and CALR-mutated patients. In multivariate analysis, JAK2V617F mutation was a risk factor regardless of whether thrombosis occurred at diagnosis (Hazard ratio=1.836; P=0.040) or during follow-up (Hazard ratio=2.678; P=0.023), but CALR mutation was not at either time. Kaplan-Meier analysis revealed a more favorable thrombosis-free survival in CALR-mutated patients than in V617F+cases (P=0.014), and the lower frequency of thrombosis in CALR-mutated patients was most likely due to the low thrombotic rate in type2CALR-mutated patients (7.9%). Although no difference concerning fibrotic transformation was found between CALR-mutated and V617F+ET (P=1.000), CALR-mutated patients had a higher degree of reticulin deposition (P=0.003). The difference was mostly ascribed to the higher rate of grade1reticulin deposition in type1CALR-mutated patients compared with V617F+patients. Screening for CALR mutations in paired samples before and after treatment indicated that CALR-mutated clones were not completely eliminated by cytoreductive treatment. Combination use of antiplatelet and cytoreductive agents decreased the risk of thrombosis in V617F+patients (P=0.034), but not in CALR-mutated cases (P=1.000). Conclusions:We confirm the value of CALR mutations in the diagnosis and prognosis of ET in Chinese patients and show the clinical correlates of type1and type2CALR muations. The present study provide new evidence for making treatment strategies based on molecular markers.
Background:Essential thrombocythemia (ET) is extremely rare in children, and the clinical course of childhood ET remains unclear because of the small sample number. Further study with a large sample size is needed.
Objectives:To evaluate the clinical manifestations, complications, treatment strategies and long-term outcomes in children diagnosed with ET.
Methods:A cohort of70children diagnosed with ET (age≤18) were retrospectively evaluated.
Results:The median age was12years (range2-18years) with a male predominance (male/female ratio,1.4). The gender distribution was different from adult ET patients. Most of children (54.3%) did not display thrombocytosis-related symptoms at diagnosis, and the presence of symptoms was positively related to platelet count (P=0.002). Compared with adult patients, children with ET had a lower frequency of JAK2V617F mutation (18.8%). Different from adult patiens, blood cell counts were not significantly different between patients with and without JAK2V617F mutation in childhood ET (P>0.05). Most of the symptoms related to thrombocytosis (82.6%) responded to antiplatelet or cytoreductive drugs. Resistance/intolerance existed in children receiving hydroxyurea, but none of them suffered from severe side effects or developed second malignancies during hydroxyurea treatment. Compared with adult patients, children with ET had a lower risk of thrombosis (1.4%). We reported the first case of ET with development of cavernous transformation of portal vein (CTPV) and transformation to overt fibrosis in the same child less than14years old. Two children (2.9%) transformed to overt fibrosis during follow-up, and increase in leukocyte count might predict the occurance of disease transformation.
Conclusions:Clinical and molecular features in children with ET are different from adult ET patients.
Background:Compared with adult patients, children with essential thrombocythemia (ET) had a lower frequency of JAK2V617F mutation. Most of the children did not harbor a well-known genetic marker, and the pathogenesis of childhood ET remains unclear.
Objectives:To investigate molecular features and clonal evolution of childhood ET, and to provide primary evidence on understanding the pathogenesis of childhood ET.
Methods:High-throughout targeted capture exome sequencing was used to explore mutations in55genes which were all related to hematologic neoplasms. All of the positive mutations were evaluated in100normal controls to exclude polymorphism. We speculated the clonal evolution based on allele frequency.
Results:The mean depth was384×, with a mean coverage of99.6%. Validations of the mutations by Sanger sequencing revealed an accuracy of93.8%. Finally,16mutations were found in11genes and in13patients. All of the16mutations were not found in healthy controls. Different from adult ET, most of the mutations in children were germline mutations (56.3%), which might be one of the important mechanisms by which the onset of the disease occurred earlier in children. JAK2V617F was positive in6patients (18.8%), and the rate was lower than that in adult ET. None of the children displayed CALR-or MPL-mutated. JAK246/1haplotype was found in12children (60%). A list of mutations accompanied with JAK2V617F mutation, including mutations in ASXL1, U2AF1, NRAS and IDH1. Genes in the JAK-STAT pathway (45%) and with epigenetic functions were mostly involved (25%). Concurrent mutations in the above two groups of genes represented20%of the children. Clone evolution analysis based on allele frequency revealed that JAK2V617F might not be the driver mutation, but was an event secondary to other mutations.
Conclusions:The mutational profile of childhood ET was different from adult ET. Germline mutations might be one of the important mechanisms by which the onset of the disease occurred earlier. JAK2V617F might be a secondary event.
研究目的：分析中国ET患者的临床及分子生物学特点,分析其血栓形成危险因素,验证IPSET-血栓模型在中国ET患者的可行性,并评价此模型对治疗的指导意义。
研究方法：回顾性分析1982年至2012年我院诊断的ET患者(年龄≥18岁),对患者病历资料进行重新评估,所有患者均符合2008年WHO诊断标准；COX比例风险模型筛选血栓形成的独立危险因素,并用C统计值评价模型的检验效能；乘积极限法(K-M曲线)绘制并比较不同危险组的生存曲线。
研究结果：纳入患者共970例,中位随访时间为49(0-360)个月。中国ET患者临床特点与欧美患者相似。其中746例检测了JAK2V617F突变,阳性患者380例(50.9%),阴性患者366例(49.1%)。随访过程中99例(10.2%)发生血栓并发症,5年、10年及15年累积血栓发生率分别为9%、22%及35%。COX模型多因素分析表明年龄>60岁[风险比(HR)=1.949]、既往血栓史(HR=2.484)、JAK2V617F突变(HR=1.719)及心血管危险因素(HR=1.877)为血栓栓塞并发症的独立危险因素,结果与IPSET-血栓模型一致。COX模型中以上危险因素的C值为0.714(95%可信区间:0.655-0.772),高于传统分层模型的C值[0.647(95%可信区间：0.577-0.717)]。根据IPSET-血栓模型将ET患者分为低危、中危及高危组,三组无血栓生存预后有统计学差异(P<0.001)。治疗方面,在中危及高危组中,接受减低血小板治疗的患者的血栓发生率均低于组内未治疗患者(P<0.05),而在低危组患者中,差异没有统计学意义(P=0.446)。减低血小板的药物可能通过减低病程中白细胞数来达到预防血栓发生的作用。
结论：我们在中国ET患者中首次验证了IPSET-血栓模型的预后指导意义,并为IPSET-血栓模型指导治疗提供了依据。
研究背景：获得性体细胞突变JAK2V617F见于约50%-60%的原发性血小板增多症(Essential Thrombocythemia, ET)患者。近期在约50%的JAK2V617F阴性ET患者中发现了钙网蛋白基因(Calreticulin, CALR)突变,在ET诊断中有重要价值。但此突变尚未在亚洲患者中报道,且其在指导治疗方面的意义尚不明确。
研究目的：评估JAK2V617F、MPL和CALR基因突变在中国ET患者中的发生率,并探讨其在ET的诊断、判断预后及治疗中的意义。
研究方法：回顾性分析1990年至2013年我院诊断的436例ET患者的临床资料,并在所有患者中检测JAK2V617F、MPL及CALR基因突变。JAK2V617F突变采用实时定量PCR法检测,采用Sanger双向测序检测MPL基因10号外显子及CALR基因9号外显子突变,并将每种CALR基因突变亚型行TA克隆后测序。COX比例风险模型筛选血栓形成的独立危险因素,乘积极限法(K-M曲线)绘制并比较不同危险组的生存曲线。
研究结果：中国ET患者的MPL突变频率(1.4%)低于欧美ET患者,但JAK2V617F突变(55.1%)及CALR突变率(22.7%)与欧美患者相似。研究发现了5种新的CALR基因插入及缺失突变。两例患者同时存在JAK2V617F及CALR突变,其中一例CALR突变为新发现的9号外显子点突变(c.997C>T),并证实此点突变为获得性体细胞突变。与JAK2V617F突变患者相比,CALR突变患者的白细胞数、中性粒细胞数、血红蛋白含量及内源性红系集落形成(EEC)阳性率较低,而血小板数较高,差异均有统计学意义(P值均<0.01)。无JAK2/MPL/CALR突变患者的白细胞数、血红蛋白含量及EEC阳性率均介于JAK2V617F突变及CALR突变患者之间。Cox模型多因素分析显示JAK2V617F突变是诊断时(HR=1.836,P=0.040)及随访过程中(HR=2.678,P=0.023)血栓形成的独立危险因素,而CALR基因突变并不是血栓危险因素。K-M曲线显示CALR突变患者的无血栓生存率高于JAK2V617F突变患者(P=0.014),这种差异可能与Ⅱ型CALR突变患者的血栓发生率(7.9%)显著低于JAK2V617F突变患者(30.0%)有关(P=0.004)。JAK2V617F突变患者的骨纤转化率与CALR突变患者无显著差异(P=1.000),但CALR突变患者的骨髓网状纤维沉积分级高于JAK2V617F突变患者(P=0.003),这种现象主要由于I型CALR突变患者中I级网状纤维增高引起。在同一患者接受减低血小板治疗前与治疗后的配对样本中分别检测CALR基因突变,发现减低血小板治疗并不能完全消除CALR突变克隆。联合应用抗血小板及减低血小板的治疗降低了JAK2V617F患者的血栓发生率(P=0.034),但未减少CALR突变患者的血栓发生(P=1.000)。
结论：我们在中国ET患者中证实了CALR基因突变在ET的诊断和判断预后中的价值,并发现JAK2V617F和CALR基因突变与临床特点及预后有关。本研究为基于分子生物学指标的治疗策略提供了初步依据。
研究背景：儿童原发性血小板增多症(essential thrombocythemia,ET)罕见,由于样本量小,临床特点并未完全明确,因此需要较大样本量研究来评估。
研究目的：评价儿童ET患者的症状特点、血栓出血并发症、疾病转化率及治疗策略。
研究方法：回顾性分析1986年至2012年于我院诊断为ET的70例儿童患者(年龄≤18岁),对患者的临床特点和实验室检查进行分析。
研究结果：中位诊断年龄为12(2-18)岁,伴有明显的男性倾向(男/女=1.4)与成人ET的女性倾向不同。多数患儿(54.3%)就诊时无血小板增多相关症状,有无临床症状与血小板数有关(P=0.002)。儿童ET的JAK2V617F阳性率(18.8%)低于成人ET。与成人不同的是,JAK2V617F突变阳性与阴性患儿的白细胞数、中性粒细胞数、血红蛋白水平及血小板数无显著差异(P均>0.05)。多数患儿(82.6%)的血小板增多相关症状可通过药物缓解。儿童ET患者使用羟基脲也存在耐药或不耐受,但长期使用未发现严重副作用,无一例继发其它恶性肿瘤。ET患儿的血栓发生率低(2.9%)于成人ET,且2例血栓患儿均为女性,其中一例为腹腔静脉血栓导致门静脉海绵样变并合并骨髓纤维化,在儿童ET中是首次报道。与成人ET一样,儿童ET转化为骨髓纤维化的比例较低(2.9%),病程中白细胞数持续升高可能是骨纤转化的前兆。
结论：儿童ET在临床转归及分子生物学特点上不同于成人ET。
研究背景：儿童原发性血小板增多症(Essential Thrombocythemia,ET)的JAK2V617F阳性率低于成人患者,多数未发现分子克隆标志,发病机制仍不清楚。
研究目的：检测儿童ET的突变位点并推测克隆演变,为揭示儿童ET的发病机制提供依据。
研究方法：采用高通量目标区域捕获测序技术在20例儿童ET患者中检测与血液肿瘤相关的55个基因突变并进行验证,验证为真阳性的所有位点在100个正常人中检测排除多态性位点。根据基因突变负荷预测克隆演变过程。
研究结果：平均测序深度为384×,平均可覆盖靶区域的99.6%,验证结果显示准确率达93.8%。最终确定16种疾病相关点突变,这些突变在100个正常人DNA样本中均未发现。共涉及突变基因11个,累及患者13例,其余7例患儿未发现疾病相关基因突变。与成人不同的是,经自身正常组织对照证实多数突变位点(56.3%)为生殖细胞突变,可能是儿童ET发病提早的重要机制之一。JAK2V617F阳性患者6例,阳性率(18.8%)低于成人ET。所有20例患儿均未发现CALR基因和MPL基因突变。JAK246/1单体型基因型显示,12例为(60%)CG杂合子,8例(40%)为CC纯合子,无GG纯合子。多种基因可以和JAK2V617F同时发生,包括ASXL1、U2AF1、NRAS和IDH1。突变基因涉及多种功能,其中JAK-STAT信号转导通路基因(45%)与表观调节基因(25%)最常累及,两类基因可合并突变(20%)。基于突变负荷的克隆性分析显示JAK2V617F突变可能是发生于表观调节基因突变后的晚期事件。
结论：儿童ET的突变谱不同于成人,JAK2V617F突变率低,且无CALR突变,可能存在与成人不同的发病机制。生殖细胞突变可能在儿童ET提前发病机制中起重要作用。JAK2V617F可能并不是驱动基因,而是其它基因突变累积到一定程度的继发改变。
Background:Essential thrombocythemia (ET) is the most common type of Philadelphia chromosome negative myeloproliferative neoplasms characterized by increased risk of vascular events (thrombosis and hemorrhage). Traditionally, advanced age≥60and history of thrombosis are regarded as predictive risk factors for thrombosis. Recently, a new International Prognostic Score of thrombosis for ET (IPSET-thrombosis) was proposed to predict thrombotic events.
Objectives:To analyze clinical and biological characteristics of ET, and to evaluate the prognostic value and clinical implication of the IPSET-thrombosis model in a large cohort of Chinese ET patients.
Methods:We retrospectively evaluated the characteristics and risk factors for thrombosis in Chinese patients diagnosed with ET in our hospital from1982to2012. Their clinical data were carefully reassessed, and all of them met the2008WHO criteria. Cox proportional hazards regression was employed to carry out univariate survival analysis, and factors that were significant were forced to multivariate survival analysis. The C-index was calculated based on Receiver Operating Characteristic curve using prognostic index. Thrombosis-free survival was estimated by Kaplan-Meier method, and log-rank test was used to compare thrombosis-free survival data.
Results:A total of970ET patients were enrolled. The median follow-up was49months (range,0-360). Chinese ET patients had similar clinical characteristics as Caucasian patients. JAK2V617F mutation was investigated in746patients among whom380(50.9%) were positive. During follow-up,99(10.2%) patients experienced at least one major thrombotic event. The5-,10-, and15-yr cumulative rates of thrombotic events were9.0%,22.0%, and35.0%, respectively. Similar to the IPSET-thrombosis study, our multivariate analysis revealed age>60(HR=1.949), previous thrombosis (HR=2.484), JAK2V617F mutation (HR=1.719), and cardiovascular risk factors (HR=1.877) as independent risk factors for thrombosis. We confirmed that the above risk factors in IPSET-thrombosis, when compared with traditional risk factors (e.g., age≥60and previous thrombotic events), were more predictive of thrombotic events (C-index0.714vs.0.647). Classification by IPSET-thrombosis risk groups revealed different cumulative thrombosis-free survival (P<0.001). For treatment, patients in the intermediate-and high-risk group derived clinical benefit from cytoreductive agents (P<0.05), but those in the low-risk group did not (P=0.446). The lower risk of thrombosis on cytoreductive therapy was related to decrease in leukocyte count during the disease course.
Conclusions:We validate the reproducibility of IPSET-thrombosis in Chinese ET patients and provide key clinical implications.
Background:Somatic JAK2V617F mutation exists in about50-60%of patients with essential thrombocythemia (ET). Recently, discovery of calreticulin (CALR) mutations, which were found in about half of ET patients with wild type JAK2, fills the molecular diagnostic gap. However, the prevalence of CALR mutations has not been reported in Asian patients, and its therapeutic implications have not yet been evaluated.
Objectives:We studied profiles of specific mutations in Chinese ET patients to provided additional details on the utility of CALR mutations in the diagnosis, prognosis and treatment of ET.
Methods:We retrospectively evaluated the clinical characteristics in436Chinese patients diagnosed with ET in our hospital from1990to2013. Mutations in JAK2V617F, MPL exon10and CALR exon9were analyzed in all of the patients. Real-time quantitative PCR assay was performed to detect JAK2V617F mutation. Mutations in CALR and MPL were assessed by bidirectional sequencing. Each type of deletions or insertions in CALR was cloned by the TA cloning system. Cox proportional hazards regression was employed to carry out univariate survival analysis, and factors that were significant were forced to multivariate survival analysis. Thrombosis-free survival was estimated by Kaplan-Meier method, and log-rank test was used to compare thrombosis-free survival data.
Results:Compared with Caucasian patients, Chinese patients had a lower frequency of MPL mutations (1.4%) but comparable JAK2V617F (55.1%) and CALR mutations (22.7%). We found5new types of deletions or insertions in CALR. Two patients harbored both JAK2V617F and CALR mutations; one of whom had a novel point mutation in CALR exon9(c.997C>T). Absence of the point mutation in T cells confirmed the mutation to be somatic. Compared with V617F+patients, CALR-mutated patients displayed lower leukocyte count, granulocyte count, hemoglobin level, lower rate of positive EECs but higher platelet count (P<0.01for each comparison). Triple-negative patients had intermediate leukocyte count, hemoglobin level, platelet count and intermediate rate of positive EECs between V617F+and CALR-mutated patients. In multivariate analysis, JAK2V617F mutation was a risk factor regardless of whether thrombosis occurred at diagnosis (Hazard ratio=1.836; P=0.040) or during follow-up (Hazard ratio=2.678; P=0.023), but CALR mutation was not at either time. Kaplan-Meier analysis revealed a more favorable thrombosis-free survival in CALR-mutated patients than in V617F+cases (P=0.014), and the lower frequency of thrombosis in CALR-mutated patients was most likely due to the low thrombotic rate in type2CALR-mutated patients (7.9%). Although no difference concerning fibrotic transformation was found between CALR-mutated and V617F+ET (P=1.000), CALR-mutated patients had a higher degree of reticulin deposition (P=0.003). The difference was mostly ascribed to the higher rate of grade1reticulin deposition in type1CALR-mutated patients compared with V617F+patients. Screening for CALR mutations in paired samples before and after treatment indicated that CALR-mutated clones were not completely eliminated by cytoreductive treatment. Combination use of antiplatelet and cytoreductive agents decreased the risk of thrombosis in V617F+patients (P=0.034), but not in CALR-mutated cases (P=1.000). Conclusions:We confirm the value of CALR mutations in the diagnosis and prognosis of ET in Chinese patients and show the clinical correlates of type1and type2CALR muations. The present study provide new evidence for making treatment strategies based on molecular markers.
Background:Essential thrombocythemia (ET) is extremely rare in children, and the clinical course of childhood ET remains unclear because of the small sample number. Further study with a large sample size is needed.
Objectives:To evaluate the clinical manifestations, complications, treatment strategies and long-term outcomes in children diagnosed with ET.
Methods:A cohort of70children diagnosed with ET (age≤18) were retrospectively evaluated.
Results:The median age was12years (range2-18years) with a male predominance (male/female ratio,1.4). The gender distribution was different from adult ET patients. Most of children (54.3%) did not display thrombocytosis-related symptoms at diagnosis, and the presence of symptoms was positively related to platelet count (P=0.002). Compared with adult patients, children with ET had a lower frequency of JAK2V617F mutation (18.8%). Different from adult patiens, blood cell counts were not significantly different between patients with and without JAK2V617F mutation in childhood ET (P>0.05). Most of the symptoms related to thrombocytosis (82.6%) responded to antiplatelet or cytoreductive drugs. Resistance/intolerance existed in children receiving hydroxyurea, but none of them suffered from severe side effects or developed second malignancies during hydroxyurea treatment. Compared with adult patients, children with ET had a lower risk of thrombosis (1.4%). We reported the first case of ET with development of cavernous transformation of portal vein (CTPV) and transformation to overt fibrosis in the same child less than14years old. Two children (2.9%) transformed to overt fibrosis during follow-up, and increase in leukocyte count might predict the occurance of disease transformation.
Conclusions:Clinical and molecular features in children with ET are different from adult ET patients.
Background:Compared with adult patients, children with essential thrombocythemia (ET) had a lower frequency of JAK2V617F mutation. Most of the children did not harbor a well-known genetic marker, and the pathogenesis of childhood ET remains unclear.
Objectives:To investigate molecular features and clonal evolution of childhood ET, and to provide primary evidence on understanding the pathogenesis of childhood ET.
Methods:High-throughout targeted capture exome sequencing was used to explore mutations in55genes which were all related to hematologic neoplasms. All of the positive mutations were evaluated in100normal controls to exclude polymorphism. We speculated the clonal evolution based on allele frequency.
Results:The mean depth was384×, with a mean coverage of99.6%. Validations of the mutations by Sanger sequencing revealed an accuracy of93.8%. Finally,16mutations were found in11genes and in13patients. All of the16mutations were not found in healthy controls. Different from adult ET, most of the mutations in children were germline mutations (56.3%), which might be one of the important mechanisms by which the onset of the disease occurred earlier in children. JAK2V617F was positive in6patients (18.8%), and the rate was lower than that in adult ET. None of the children displayed CALR-or MPL-mutated. JAK246/1haplotype was found in12children (60%). A list of mutations accompanied with JAK2V617F mutation, including mutations in ASXL1, U2AF1, NRAS and IDH1. Genes in the JAK-STAT pathway (45%) and with epigenetic functions were mostly involved (25%). Concurrent mutations in the above two groups of genes represented20%of the children. Clone evolution analysis based on allele frequency revealed that JAK2V617F might not be the driver mutation, but was an event secondary to other mutations.
Conclusions:The mutational profile of childhood ET was different from adult ET. Germline mutations might be one of the important mechanisms by which the onset of the disease occurred earlier. JAK2V617F might be a secondary event.
引文
1. Cervantes F, Passamonti F, Barosi G. Life expectancy and prognostic factors in the classic BCR/ABL-negative myeloproliferative disorders. Leukemia 2008;22:905-914.
2. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
3. Yeh YM, Chen YL, Cheng HY, et al. High percentage of JAK2 exon 12 mutation in Asian patients with polycythemia vera. American journal of clinical pathology 2010; 134:266-270.
4. Xu Z, Gale RP, Zhang Y, et al. Unique features of primary myelofibrosis in Chinese. Blood 2012;119:2469-2473.
5. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
6. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
7. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012;120:1197-1201.
8. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
9. Mustjoki S, Borze I, Lasho TL, et al. JAK2V617F mutation and spontaneous megakaryocytic or erythroid colony formation in patients with essential thrombocythaemia (ET) or polycythaemia vera (PV). Leukemia research 2009;33:54-59.
10. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
11. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
12. McNally RJ, Rowland D, Roman E, et al. Age and sex distributions of hematological malignancies in the U.K. Hematological oncology 1997;15:173-189.
13. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
14. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
15. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
16. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
17. Wolanskyj AP, Schwager SM, McClure RF, et al. Essential thrombocythemia beyond the first decade:life expectancy, long-term complication rates, and prognostic factors. Mayo Clinic proceedings Mayo Clinic 2006;81:159-166.
18. Chim CS, Kwong YL, Lie AK, et al. Long-term outcome of 231 patients with essential thrombocythemia:prognostic factors for thrombosis, bleeding, myelofibrosis, and leukemia. Archives of internal medicine 2005;165:2651-2658.
19. Tefferi A, Elliott M. Thrombosis in myeloproliferative disorders:prevalence, prognostic factors, and the role of leukocytes and JAK2V617F. Seminars in thrombosis and hemostasis 2007;33:313-320.
20. Abdulkarim K, Girodon F, Johansson P, et al. AML transformation in 56 patients with Ph-MPD in two well defined populations. European journal of haematology 2009;82:106-111.
21. Bang SM, Lee JS, Ahn JY, et al. Vascular events in Korean patients with myeloproliferative neoplasms and their relationship to JAK2 mutation. Thrombosis and haemostasis 2009;101:547-551.
22. Cheung B, Radia D, Pantelidis P, et al. The presence of the JAK2 V617F mutation is associated with a higher haemoglobin and increased risk of thrombosis in essential thrombocythaemia. British journal of haematology 2006; 132:244-245.
23. Carobbio A, Finazzi G, Antonioli E, et al. JAK2V617F allele burden and thrombosis:a direct comparison in essential thrombocythemia and polycythemia vera. Experimental hematology 2009;37:1016-1021.
24. Antonioli E, Guglielmelli P, Poli G, et al. Influence of JAK2V617F allele burden on phenotype in essential thrombocythemia. Haematologica 2008;93:41-48.
25. De Stefano V, Rossi E, Za T, et al. JAK2 V617F mutational frequency in essential thrombocythemia associated with splanchnic or cerebral vein thrombosis. American journal of hematology 2011;86:526-528.
26. Dahabreh IJ, Zoi K, Giannouli S, et al. Is JAK2 V617F mutation more than a diagnostic index? A meta-analysis of clinical outcomes in essential thrombocythemia. Leukemia research 2009;33:67-73.
27. Ziakas PD. Effect of JAK2 V617F on thrombotic risk in patients with essential thrombocythemia: measuring the uncertain. Haematologica 2008;93:1412-1414.
28. Lussana F, Caberlon S, Pagani C, et al. Association of V617F Jak2 mutation with the risk of thrombosis among patients with essential thrombocythaemia or idiopathic myelofibrosis:a systematic review. Thrombosis research 2009;124:409-417.
29. Lee HS, Park LC, Lee EM, et al. Incidence rates and risk factors for vascular events in patients with essential thrombocythemia:a multicenter study from Korea. Clinical lymphoma, myeloma & leukemia 2012; 12:70-75.
30. Arellano-Rodrigo E, Alvarez-Larran A, Reverter JC, et al. Increased platelet and leukocyte activation as contributing mechanisms for thrombosis in essential thrombocythemia and correlation with the JAK2 mutational status. Haematologica 2006;91:169-175.
31. Besses C, Cervantes F, Pereira A, et al. Major vascular complications in essential thrombocythemia:a study of the predictive factors in a series of 148 patients. Leukemia 1999;13:150-154.
32. Radaelli F, Colombi M, Calori R, et al. Analysis of risk factors predicting thrombotic and/or haemorrhagic complications in 306 patients with essential thrombocythemia. Hematological oncology 2007;25:115-120.
33. Carobbio A, Antonioli E, Guglielmelli P, et al. Leukocytosis and risk stratification assessment in essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2008;26:2732-2736.
34. Carobbio A, Finazzi G, Guerini V, et al. Leukocytosis is a risk factor for thrombosis in essential thrombocythemia:interaction with treatment, standard risk factors, and Jak2 mutation status. Blood 2007;109:2310-2313.
35. Barbui T, Carobbio A, Rambaldi A, et al. Perspectives on thrombosis in essential thrombocythemia and polycythemia vera:is leukocytosis a causative factor? Blood 2009:114:759-763.
36. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
37. Haznedaroglu IC. The therapeutic goals of essential thrombocythemia under the clouds of over-treatment and under-treatment. Expert opinion on pharmacotherapy 2013;14:1431-1436.
38. Tefferi A, Barbui T. Personalized management of essential thrombocythemia-application of recent evidence to clinical practice. Leukemia 2013;27:1617-1620.
39. Trelinski J, Chojnowski K, Cebula-Obrzut B, et al. Impaired apoptosis of megakaryocytes and bone marrow mononuclear cells in essential thrombocythemia:correlation with JAK2V617F mutational status and cytoreductive therapy. Medical oncology (Northwood, London, England) 2012;29:2388-2395.
40. Trelinski J, Wierzbowska A, Krawczynska A, et al. Plasma levels of angiogenic factors and circulating endothelial cells in essential thrombocythemia:correlation with cytoreductive therapy and JAK2-V617F mutational status. Leukemia & lymphoma 2010;51:1727-1733.
1. Kralovics R, Passamonti F, Buser AS, et al. A gain-of-function mutation of JAK2 in myeloproliferative disorders. The New England journal of medicine 2005;352:1779-1790.
2. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008;112:844-847.
3. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
4. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
5. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
6. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
7. Tefferi A, Thiele J, Vannucchi AM, et al. An overview on CALR and CSF3R mutations and a proposal for revision of WHO diagnostic criteria for myeloproliferative neoplasms. Leukemia 2014.
8. Lundberg P, Karow A, Nienhold R, et al. Clonal evolution and clinical correlates of somatic mutations in myeloproliferative neoplasms. Blood 2014.
9. Tefferi A, Pardanani A. Genetics:CALR mutations and a new diagnostic algorithm for MPN. Nature reviews Clinical oncology 2014.
10. Tefferi A, Guglielmelli P, Lasho TL, et al. CALR and ASXL1 mutations-based molecular prognostication in primary myelofibrosis:an international study of 570 patients. Leukemia 2014.
11. Guglielmelli P, Nangalia J, Green AR, et al. CALR mutations in myeloproliferative neoplasms: Hidden behind the reticulum. American journal of hematology 2014.
12. Tefferi A, Lasho TL, Finke CM, et al. CALR vs JAK2 vs MPL-mutated or triple-negative myelofibrosis:clinical, cytogenetic and molecular comparisons. Leukemia 2014.
13. Panagiota V, Thol F, Markus B, et al. Prognostic effect of calreticulin mutations in patients with myelofibrosis after allogeneic hematopoietic stem cell transplantation. Leukemia 2014.
14. Chi J, Nicolaou KA, Nicolaidou V, et al. Calreticulin gene exon 9 frameshift mutations in patients with thrombocytosis. Leukemia 2013.
15. Levine RL. Another piece of the myeloproliferative neoplasms puzzle. The New England journal of medicine 2013;369:2451-2452.
16. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
17. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
18. Swerdllow S, Campo E, Harris NL. WHO classification of tumours of haematopoietic and lymphoid tissues. France:IARC Press,2008; 2008.
19. Manoharan A, Horsley R, Pitney WR. The reticulin content of bone marrow in acute leukaemia in adults. British journal of haematology 1979;43:185-190.
20. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
21. Mustjoki S, Borze I, Lasho TL, et al. JAK2V617F mutation and spontaneous megakaryocytic or erythroid colony formation in patients with essential thrombocythaemia (ET) or polycythaemia vera (PV). Leukemia research 2009;33:54-59.
22. Carobbio A, Finazzi G, Antonioli E, et al. JAK2V617F allele burden and thrombosis:a direct comparison in essential thrombocythemia and polycythemia vera. Experimental hematology 2009;37:1016-1021.
23. Brecqueville M, Rey J, Bertucci F, et al. Mutation analysis of ASXL1, CBL, DNMT3A, IDH1, IDH2, JAK2, MPL, NF1, SF3B1, SUZ12, and TET2 in myeloproliferative neoplasms. Genes, chromosomes & cancer 2012;51:743-755.
24. Green MR, Gentles AJ, Nair RV, et al. Hierarchy in somatic mutations arising during genomic evolution and progression of follicular lymphoma. Blood 2013; 121:1604-1611.
25. Lasho TL, Elliott MA, Pardanani A, et al. CALR mutation studies in chronic neutrophilic leukemia. American journal of hematology 2014.
26. Vannucchi AM, Rotunno G, Bartalucci N, et al. Calreticulin mutation-specific immunostaining in myeloproliferative neoplasms:pathogenetic insight and diagnostic value. Leukemia 2014.
27. Tefferi A, Lasho TL, Finke C, et al. Type 1 vs type 2 calreticulin mutations in primary myelofibrosis:differences in phenotype and prognostic impact. Leukemia 2014.
1. Mesa RA, Silverstein, M.N., Jacobsen, S.J., Wollan, P.C., and Tefferi, A. Population-based incidence and survival figures in essential thrombocythemia and agnogenic myeloid metaplasia: an Olmsted County Study. Am J Hematol 1999;61:10-15.
2. Hasle H. Incidence of essential thrombocythaemia in children. British journal of haematology 2000;110:751.
3. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
4. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
5. Randi ML, Putti MC, Scapin M, et al. Pediatric patients with essential thrombocythemia are mostly polyclonal and V617FJAK2 negative. Blood 2006;108:3600-3602.
6. El-Moneim AA, Kratz CP, Boll S, et al. Essential versus reactive thrombocythemia in children: retrospective analyses of 12 cases. Pediatric blood & cancer 2007;49:52-55.
7. Teofili L, Giona F, Martini M, et al. Markers of myeloproliferative diseases in childhood polycythemia vera and essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2007;25:1048-1053.
8. Teofili L, Giona F, Martini M, et al. The revised WHO diagnostic criteria for Ph-negative myeloproliferative diseases are not appropriate for the diagnostic screening of childhood polycythemia vera and essential thrombocythemia. Blood 2007;110:3384-3386.
9. Nakatani T, Imamura T, Ishida H, et al. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia, Pediatric blood & cancer 2008;51:802-805.
10. Veselovska J PD, Pekova S, Horvathova M, Solna R, Cmejlova J, Cmejla R, Belickova M, Mihal V, Stary J, Divoky V. Most pediatric patients with essential thrombocythemia show hypersensitivity to erythropoietin in vitro, with rare JAK2 V617F-positive erythroid colonies. Leukemia research 2008;32:369-377.
11. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
12. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
13. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
14. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
15. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
16. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
17. Langabeer SE, Haslam K, McMahon C. CALR mutations are rare in childhood essential thrombocythemia. Pediatric blood & cancer 2014.
18. Manoharan A, Horsley R, Pitney WR. The reticulin content of bone marrow in acute leukaemia in adults. British journal of haematology 1979;43:185-190.
19. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
20. Barosi G, Besses C, Birgegard G, et al. A unified definition of clinical resistance/intolerance to hydroxyurea in essential thrombocythemia:results of a consensus process by an international working group. Leukemia 2007;21:277-280.
21. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
22. McNally RJ, Rowland D, Roman E, et al. Age and sex distributions of hematological malignancies in the U.K. Hematological oncology 1997;15:173-189.
23. Frewin R, Dowson A. Headache in essential thrombocythaemia. International journal of clinical practice 2012;66:976-983.
24. Kesler A, Ellis MH, Manor Y, et al. Neurological complications of essential thrombocytosis (ET). Acta neurologica Scandinavica 2000; 102:299-302.
25. Cassidy EM, Tomkins E, Dinan T, et al. Central 5-HT receptor hypersensitiviry in migraine without aura. Cephalalgia:an international journal of headache 2003;23:29-34.
26. Hanington E. Migraine:the platelet hypothesis after 10 years. Biomedicine & pharmacotherapy= Biomedecine& pharmacotherapie 1989;43:719-726.
27. Izzati-Zade KF. The role of serotonin in the pathogenesis and clinical presentations of migraine attacks. Neuroscience and behavioral physiology 2008;38:501-505.
28. Cesar JM, de Miguel D, Garcia Avello A, et al. Platelet dysfunction in primary thrombocythemia using the platelet function analyzer, PFA-100. American journal of clinical pathology 2005;123:772-777.
29. Bellucci S, Michiels JJ. Spontaneous proliferative megakaryocytopoiesis and platelet hyperreactivity in essential thrombocythemia:is thrombopoietin the link? Annals of hematology 2000;79:51-58.
30. Dos Santos LC, Ribeiro JC, Silva NP, et al. Cytogenetics, JAK2 and MPL mutations in polycythemia vera, primary myelofibrosis and essential thrombocythemia. Revista brasileira de hematologia e hemoterapia 2011;33:417-424.
31. Gangat N, Tefferi A, Thanarajasingam G, et al. Cytogenetic abnormalities in essential thrombocythemia:prevalence and prognostic significance. European journal of haematology 2009;83:17-21.
32. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
33. Hernandez-Boluda JC, Alvarez-Larran A, Gomez M, et al. Clinical evaluation of the European LeukaemiaNet criteria for clinicohaematological response and resistance/intolerance to hydroxycarbamide in essential thrombocythaemia. British journal of haematology 2011;152:81-88.
34. Leung AK, Robson WL, Liu EK, et al. Melanonychia striata in Chinese children and adults. International journal of dermatology 2007;46:920-922.
35. Wiechert A, Reinhard G, Tuting T, et al. Multiple skin cancers in a patient treated with hydroxyurea. Der Hautarzt; Zeitschrift fur Dermatologie, Venerologie, und verwandte Gebiete 2009;60:651-652,654.
36. Murray NP, Tapia P, Porcell J, et al. Acquired melanonychia in Chilean patients with essential thrombocythemia treated with hydroxyurea:a report of 7 clinical cases and review of the literature. ISRN dermatology 2013;2013:325246.
37. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
38. Kinney TR HR, O'Branski EE, Ohene-Frempong K, Wang W, Daeschner C, Vichinsky E, Redding-Lallinger R, Gee B, Platt OS, Ware RE. Safety of hydroxyurea in children with sickle cell anemia:results of the HUG-KIDS study, a phase Ⅰ/Ⅱ trial. Pediatric Hydroxyurea Group. Blood 1999;94:1550-1554.
39. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
40. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
41. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012;120:1197-1201.
42. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
43. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
44. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
45. Finazzi G, Carobbio A, Thiele J, et al. Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria. Leukemia 2012;26:716-719.
46. Yang RC, Qian LS. Essential thrombocythaemia in children:a report of nine cases. British journal of haematology 2000;110:1009-1010.
47. Teofili L, Cenci T, Martini M, et al. The mutant JAK2 allele burden in children with essential thrombocythemia. British journal of haematology 2009;145:430-432.
48. Gangat N, Wolanskyj AP, Tefferi A. Abdominal vein thrombosis in essential thrombocythemia: prevalence, clinical correlates, and prognostic implications. European journal of haematology 2006;77:327-333.
49. Johnson M, Gernsheimer T, Johansen K. Essential thrombocytosis:underemphasized cause of large-vessel thrombosis. Journal of vascular surgery 1995;22:443-447; discussion 448-449.
50. Elliott MA, Tefferi A. Thrombosis and haemorrhage in polycythaemia vera and essential thrombocythaemia. British journal of haematology 2005;128:275-290.
51. Mossier C, Kerbl R, Wagner T, et al. Portal vein thrombosis in a 17-year-old female adolescent with essential thrombocytosis. Pediatric hematology and oncology 1997; 14:457-462.
1. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
2. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008;112:844-847.
3. Brecqueville M, Rey J, Bertucci F, et al. Mutation analysis of ASXL1, CBL, DNMT3A, IDH1, IDH2, JAK2, MPL, NF1, SF3B1, SUZ12, and TET2 in myeloproliferative neoplasms. Genes, chromosomes & cancer 2012;51:743-755.
4. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
5. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
6. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
7. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
8. Farruggia P, D'Angelo P, La Rosa M, et al. MPL W515L mutation in pediatric essential thrombocythemia. Pediatric blood & cancer 2013;60:E52-54.
9. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
10. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
11. Lambert MP, Jiang J, Batra V, et al. A novel mutation in MPL (Y252H) results in increased thrombopoietin sensitivity in essential thrombocythemia. American journal of hematology 2012;87:532-534.
12. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
13. Reuther GW. Recurring mutations in myeloproliferative neoplasms alter epigenetic regulation of gene expression. American journal of cancer research 2011;1:752-762.
14. Hou Y, Song L, Zhu P, et al. Single-cell exome sequencing and monoclonal evolution of a JAK2-negative myeloproliferative neoplasm. Cell 2012;148:873-885.
15. Greenberg PL. Molecular and genetic features of myelodysplastic syndromes. International journal of laboratory hematology 2012;34:215-222.
16. Tefferi A. Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms:JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1. Leukemia 2010;24:1128-1138.
17. Larsson CA, Cote G, Quintas-Cardama A. The changing mutational landscape of acute myeloid leukemia and myelodysplastic syndrome. Molecular cancer research:MCR 2013; 11:815-827.
18. Hermouet S, Vilaine M. The JAK246/1 haplotype:a marker of inappropriate myelomonocytic response to cytokine stimulation, leading to increased risk of inflammation, myeloid neoplasm, and impaired defense against infection? Haematologica 2011;96:1575-1579.
19. Zhang X, Hu T, Wu Z, et al. The JAK246/1 haplotype is a risk factor for myeloproliferative neoplasms in Chinese patients. International journal of hematology 2012;96:611-616.
20. Kondo T, Okabe M, Sanada M, et al. Familial essential thrombocythemia associated with one-base deletion in the 5'-untranslated region of the thrombopoietin gene. Blood 1998;92:1091-1096.
21. Ding J, Komatsu H, Iida S, et al. The Asn505 mutation of the c-MPL gene, which causes familial essential thrombocythemia, induces autonomous homodimerization of the c-Mpl protein due to strong amino acid polarity. Blood 2009;114:3325-3328.
22. Etheridge SL, Cosgrove ME, Sangkhae V, et al. A novel activating, germline JAK2 mutation, JAK2R564Q, causes familial essential thrombocytosis. Blood 2014;123:1059-1068.
23. Marty C, Saint-Martin C, Pecquet C, et al. Germ-line JAK2 mutations in the kinase domain are responsible for hereditary thrombocytosis and are resistant to JAK2 and HSP90 inhibitors. Blood 2014;123:1372-1383.
24. Tefferi A. JAK inhibitors for myeloproliferative neoplasms:clarifying facts from myths. Blood 2012;119:2721-2730.
25. Papaemmanuil E, Gerstung M, Malcovati L, et al. Clinical and biological implications of driver mutations in myelodysplastic syndromes. Blood 2013;122:3616-3627; quiz 3699.
26. Jones AV, Cross NC. Inherited predisposition to myeloproliferative neoplasms. Therapeutic advances in hematology 2013;4:237-253.
1. Cervantes F, Passamonti F, Barosi G. Life expectancy and prognostic factors in the classic BCR/ABL-negative myeloproliferative disorders. Leukemia 2008;22:905-914.
2. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
3. Mesa RA, Silverstein, M.N., Jacobsen, S.J., Wollan, P.C., and Tefferi, A. Population-based incidence and survival figures in essential thrombocythemia and agnogenic myeloid metaplasia: an Olmsted County Study. Am J Hematol 1999;61:10-15.
4. Hasle H. Incidence of essential thrombocythaemia in children. British journal of haematology 2000;110:751.
5. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
6. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
7. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
8. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012; 120:1197-1201.
9. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
10. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
11. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
12. Finazzi G, Carobbio A, Thiele J, et al. Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria. Leukemia 2012;26:716-719.
13. Veselovska J PD, Pekova S, Horvathova M, Solna R, Cmejlova J, Cmejla R, Belickova M, Mihal V, Stary J, Divoky V. Most pediatric patients with essential thrombocythemia show hypersensitivity to erythropoietin in vitro, with rare JAK2 V617F-positive erythroid colonies. Leukemia research 2008;32:369-377.
14. Randi ML, Putti MC, Scapin M, et al. Pediatric patients with essential thrombocythemia are mostly polyclonal and V617FJAK2 negative. Blood 2006;108:3600-3602.
15. Teofili L, Giona F, Martini M, et al. Markers of myeloproliferative diseases in childhood polycythemia vera and essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2007;25:1048-1053.
16. Yang RC, Qian LS. Essential thrombocythaemia in children:a report of nine cases. British journal of haematology 2000;110:1009-1010.
17. Teofili L, Cenci T, Martini M, et al. The mutant JAK2 allele burden in children with essential thrombocythemia. British journal of haematology 2009; 145:430-432.
18. Nakatani T, Imamura T, Ishida H, et al. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia. Pediatric blood & cancer 2008;51:802-805.
19. Teofili L, Giona F, Martini M, et al. The revised WHO diagnostic criteria for Ph-negative myeloproliferative diseases are not appropriate for the diagnostic screening of childhood polycythemia vera and essential thrombocythemia. Blood 2007;110:3384-3386.
20. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
21. El-Moneim AA, Kratz CP, Boll S, et al. Essential versus reactive thrombocythemia in children: retrospective analyses of 12 cases. Pediatric blood & cancer 2007;49:52-55.
22. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
23. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
24. Farruggia P, D'Angelo P, La Rosa M, et al. MPL W515L mutation in pediatric essential thrombocythemia. Pediatric blood & cancer 2013;60:E52-54.
25. Lambert MP, Jiang J, Batra V, et al. A novel mutation in MPL (Y252H) results in increased thrombopoietin sensitivity in essential thrombocythemia. American journal of hematology 2012;87:532-534.
26. Pardanani AD, Levine RL, Lasho T, et al. MPL515 mutations in myeloproliferative and other myeloid disorders:a study of 1182 patients. Blood 2006;108:3472-3476.
27. Beer PA, Campbell PJ, Scott LM, et al. MPL mutations in myeloproliferative disorders:analysis of the PT-1 cohort. Blood 2008;112:141-149.
28. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008; 112:844-847.
29. Kondo T, Okabe M, Sanada M, et al. Familial essential thrombocythemia associated with one-base deletion in the 5'-untranslated region of the thrombopoietin gene. Blood 1998;92:1091-1096.
30. Ding J, Komatsu H, Iida S, et al. The Asn505 mutation of the c-MPL gene, which causes familial essential thrombocythemia, induces autonomous homodimerization of the c-Mpl protein due to strong amino acid polarity. Blood 2009;114:3325-3328.
31. Etheridge SL, Cosgrove ME, Sangkhae V, et al. A novel activating, germline JAK2 mutation, JAK2R564Q, causes familial essential thrombocytosis. Blood 2014;123:1059-1068.
32. Marty C, Saint-Martin C, Pecquet C, et al. Germ-line JAK2 mutations in the kinase domain are responsible for hereditary thrombocytosis and are resistant to JAK2 and HSP90 inhibitors. Blood 2014;123:1372-1383.
33. Cilloni D, Carturan S, Gottardi E, et al. Usefulness of the quantitative assessment of PRV-1 gene expression for the diagnosis of polycythemia vera and essential thrombocythemia patients. Blood 2004;103:2428.
34. Johansson P, Ricksten A, Wennstrom L, et al. Increased risk for vascular complications in PRV-1 positive patients with essential thrombocythaemia. British journal of haematology 2003;123:513-516.
35. Vannucchi AM, Grossi A, Pancrazzi A, et al. PRV-1, erythroid colonies and platelet Mpl are unrelated to thrombosis in essential thrombocythaemia. British journal of haematology 2004;127:214-219.
36. Gale RE, Allen AJ, Nash MJ, et al. Long-term serial analysis of X-chromosome inactivation patterns and JAK2 V617F mutant levels in patients with essential thrombocythemia show that minor mutant-positive clones can remain stable for many years. Blood 2007;109:1241-1243.
37. Michiels JJ, Juvonen E. Proposal for revised diagnostic criteria of essential thrombocythemia and polycythemia vera by the Thrombocythemia Vera Study Group. Seminars in thrombosis and hemostasis 1997;23:339-347.
38. Vardiman JW, Harris NL, Brunning RD. The World Health Organization (WHO) classification of the myeloid neoplasms. Blood 2002;100:2292-2302.
39. Chan GC, Ma SK, Ha SY, et al. Childhood essential thrombocythaemia without evidence of myeloproliferation:how many investigations should be done? British journal of haematology 2000;110:1002.
40. Dame C, Sutor AH. Primary and secondary thrombocytosis in childhood. British journal of haematology 2005;129:165-177.
41. Chiarello P, Magnolia M, Rubino M, et al. Thrombocytosis in children. Minerva pediatrica 2011;63:507-513.
42. Dror Y, Blanchette VS. Essential thrombocythaemia in children. British journal of haematology 1999; 107:691-698.
43. Teofili L, Giona F, Torti L, et al. Hereditary thrombocytosis caused by MPLSer505Asn is associated with a high thrombotic risk, splenomegaly and progression to bone marrow fibrosis. Haematologica 2010;95:65-70.
44. Liu K, Kralovics R, Rudzki Z, et al. A de novo splice donor mutation in the thrombopoietin gene causes hereditary thrombocythemia in a Polish family. Haematologica 2008;93:706-714.
45. Teofili L LL. Advances in understanding the pathogenesis of familial thrombocythaemia. British journal of haematology 2011;152:701-712.
46. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
47. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
48. Harrison CN, Bareford D, Butt N, et al. Guideline for investigation and management of adults and children presenting with a thrombocytosis. British journal of haematology 2010;149:352-375.
49. Bennett CL, Starko KM, Thomsen HS, et al. Linking drugs to obscure illnesses:lessons from pure red cell aplasia, nephrogenic systemic fibrosis, and Reye's syndrome, a report from the Southern Network on Adverse Reactions (SONAR). Journal of general internal medicine 2012;27:1697-1703.
50. Cervantes F. Management of essential thrombocythemia. Hematology/the Education Program of the American Society of Hematology American Society of Hematology Education Program 2011;2011:215-221.
51. Tefferi A. Myeloproliferative neoplasms 2012:the John M. Bennett 80th birthday anniversary lecture. Leukemia research 2012;36:1481-1489.
52. Barbui T. How to manage children and young adults with myeloproliferative neoplasms. Leukemia 2012;26:1452-1457.
53. Cortelazzo S, Finazzi G, Ruggeri M, et al. Hydroxyurea for patients with essential thrombocythemia and a high risk of thrombosis. The New England journal of medicine 1995;332:1132-1136.
54. Finazzi G, Ruggeri M, Rodeghiero F, et al. Efficacy and safety of long-term use of hydroxyurea in young patients with essential thrombocythemia and a high risk of thrombosis. Blood 2003;101:3749.
55. Radaelli F, Onida F, Rossi FG, et al. Second malignancies in essential thrombocythemia (ET):a retrospective analysis of 331 patients with long-term follow-up from a single institution. Hematology 2008;13:195-202.
56. Bjorkholm M DA, Hultcrantz M, Kristinsson SY, Ekstrand C, Goldin LR, Andreasson B, Birgegard G, Linder O, Malm C, Markevarn B, Nilsson L, Samuelsson J, Granath F, Landgren O. Treatment-related risk factors for transformation to acute myeloid leukemia and myelodysplastic syndromes in myeloproliferative neoplasms. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29.
57. Kinney TR HR, O'Branski EE, Ohene-Frempong K, Wang W, Daeschner C, Vichinsky E, Redding-Lallinger R, Gee B, Platt OS, Ware RE. Safety of hydroxyurea in children with sickle cell anemia:results of the HUG-KIDS study, a phase Ⅰ/Ⅱ trial. Pediatric Hydroxyurea Group. Blood 1999;94:1550-1554.
58. Quintas-Cardama A, Kantarjian H, Manshouri T, et al. Pegylated interferon alfa-2a yields high rates of hematologic and molecular response in patients with advanced essential thrombocythemia and polycythemia vera. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2009;27:5418-5424.
59. Mazzucconi MG, Redi R, Bernasconi S, et al. A long-term study of young patients with essential thrombocythemia treated with anagrelide. Haematologica 2004;89:1306-1313.
60. Gisslinger H, Gotic M, Holowiecki J, et al. Anagrelide compared with hydroxyurea in WHO-classified essential thrombocythemia:the ANAHYDRET Study, a randomized controlled trial. Blood 2013;121:1720-1728.
61. Hernandez-Boluda JC, Pereira A, Cervantes F, et al. Clinical evaluation of the European LeukemiaNet response criteria in patients with essential thrombocythemia treated with anagrelide. Annals of hematology 2013.
62. Harrison CN, Campbell PJ, Buck G, et al. Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia. The New England journal of medicine 2005;353:33-45.
63. Campbell PJ, Bareford D, Erber WN, et al. Reticulin accumulation in essential thrombocythemia: prognostic significance and relationship to therapy. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2009;27:2991-2999.
2. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
3. Yeh YM, Chen YL, Cheng HY, et al. High percentage of JAK2 exon 12 mutation in Asian patients with polycythemia vera. American journal of clinical pathology 2010; 134:266-270.
4. Xu Z, Gale RP, Zhang Y, et al. Unique features of primary myelofibrosis in Chinese. Blood 2012;119:2469-2473.
5. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
6. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
7. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012;120:1197-1201.
8. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
9. Mustjoki S, Borze I, Lasho TL, et al. JAK2V617F mutation and spontaneous megakaryocytic or erythroid colony formation in patients with essential thrombocythaemia (ET) or polycythaemia vera (PV). Leukemia research 2009;33:54-59.
10. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
11. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
12. McNally RJ, Rowland D, Roman E, et al. Age and sex distributions of hematological malignancies in the U.K. Hematological oncology 1997;15:173-189.
13. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
14. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
15. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
16. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
17. Wolanskyj AP, Schwager SM, McClure RF, et al. Essential thrombocythemia beyond the first decade:life expectancy, long-term complication rates, and prognostic factors. Mayo Clinic proceedings Mayo Clinic 2006;81:159-166.
18. Chim CS, Kwong YL, Lie AK, et al. Long-term outcome of 231 patients with essential thrombocythemia:prognostic factors for thrombosis, bleeding, myelofibrosis, and leukemia. Archives of internal medicine 2005;165:2651-2658.
19. Tefferi A, Elliott M. Thrombosis in myeloproliferative disorders:prevalence, prognostic factors, and the role of leukocytes and JAK2V617F. Seminars in thrombosis and hemostasis 2007;33:313-320.
20. Abdulkarim K, Girodon F, Johansson P, et al. AML transformation in 56 patients with Ph-MPD in two well defined populations. European journal of haematology 2009;82:106-111.
21. Bang SM, Lee JS, Ahn JY, et al. Vascular events in Korean patients with myeloproliferative neoplasms and their relationship to JAK2 mutation. Thrombosis and haemostasis 2009;101:547-551.
22. Cheung B, Radia D, Pantelidis P, et al. The presence of the JAK2 V617F mutation is associated with a higher haemoglobin and increased risk of thrombosis in essential thrombocythaemia. British journal of haematology 2006; 132:244-245.
23. Carobbio A, Finazzi G, Antonioli E, et al. JAK2V617F allele burden and thrombosis:a direct comparison in essential thrombocythemia and polycythemia vera. Experimental hematology 2009;37:1016-1021.
24. Antonioli E, Guglielmelli P, Poli G, et al. Influence of JAK2V617F allele burden on phenotype in essential thrombocythemia. Haematologica 2008;93:41-48.
25. De Stefano V, Rossi E, Za T, et al. JAK2 V617F mutational frequency in essential thrombocythemia associated with splanchnic or cerebral vein thrombosis. American journal of hematology 2011;86:526-528.
26. Dahabreh IJ, Zoi K, Giannouli S, et al. Is JAK2 V617F mutation more than a diagnostic index? A meta-analysis of clinical outcomes in essential thrombocythemia. Leukemia research 2009;33:67-73.
27. Ziakas PD. Effect of JAK2 V617F on thrombotic risk in patients with essential thrombocythemia: measuring the uncertain. Haematologica 2008;93:1412-1414.
28. Lussana F, Caberlon S, Pagani C, et al. Association of V617F Jak2 mutation with the risk of thrombosis among patients with essential thrombocythaemia or idiopathic myelofibrosis:a systematic review. Thrombosis research 2009;124:409-417.
29. Lee HS, Park LC, Lee EM, et al. Incidence rates and risk factors for vascular events in patients with essential thrombocythemia:a multicenter study from Korea. Clinical lymphoma, myeloma & leukemia 2012; 12:70-75.
30. Arellano-Rodrigo E, Alvarez-Larran A, Reverter JC, et al. Increased platelet and leukocyte activation as contributing mechanisms for thrombosis in essential thrombocythemia and correlation with the JAK2 mutational status. Haematologica 2006;91:169-175.
31. Besses C, Cervantes F, Pereira A, et al. Major vascular complications in essential thrombocythemia:a study of the predictive factors in a series of 148 patients. Leukemia 1999;13:150-154.
32. Radaelli F, Colombi M, Calori R, et al. Analysis of risk factors predicting thrombotic and/or haemorrhagic complications in 306 patients with essential thrombocythemia. Hematological oncology 2007;25:115-120.
33. Carobbio A, Antonioli E, Guglielmelli P, et al. Leukocytosis and risk stratification assessment in essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2008;26:2732-2736.
34. Carobbio A, Finazzi G, Guerini V, et al. Leukocytosis is a risk factor for thrombosis in essential thrombocythemia:interaction with treatment, standard risk factors, and Jak2 mutation status. Blood 2007;109:2310-2313.
35. Barbui T, Carobbio A, Rambaldi A, et al. Perspectives on thrombosis in essential thrombocythemia and polycythemia vera:is leukocytosis a causative factor? Blood 2009:114:759-763.
36. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
37. Haznedaroglu IC. The therapeutic goals of essential thrombocythemia under the clouds of over-treatment and under-treatment. Expert opinion on pharmacotherapy 2013;14:1431-1436.
38. Tefferi A, Barbui T. Personalized management of essential thrombocythemia-application of recent evidence to clinical practice. Leukemia 2013;27:1617-1620.
39. Trelinski J, Chojnowski K, Cebula-Obrzut B, et al. Impaired apoptosis of megakaryocytes and bone marrow mononuclear cells in essential thrombocythemia:correlation with JAK2V617F mutational status and cytoreductive therapy. Medical oncology (Northwood, London, England) 2012;29:2388-2395.
40. Trelinski J, Wierzbowska A, Krawczynska A, et al. Plasma levels of angiogenic factors and circulating endothelial cells in essential thrombocythemia:correlation with cytoreductive therapy and JAK2-V617F mutational status. Leukemia & lymphoma 2010;51:1727-1733.
1. Kralovics R, Passamonti F, Buser AS, et al. A gain-of-function mutation of JAK2 in myeloproliferative disorders. The New England journal of medicine 2005;352:1779-1790.
2. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008;112:844-847.
3. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
4. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
5. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
6. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
7. Tefferi A, Thiele J, Vannucchi AM, et al. An overview on CALR and CSF3R mutations and a proposal for revision of WHO diagnostic criteria for myeloproliferative neoplasms. Leukemia 2014.
8. Lundberg P, Karow A, Nienhold R, et al. Clonal evolution and clinical correlates of somatic mutations in myeloproliferative neoplasms. Blood 2014.
9. Tefferi A, Pardanani A. Genetics:CALR mutations and a new diagnostic algorithm for MPN. Nature reviews Clinical oncology 2014.
10. Tefferi A, Guglielmelli P, Lasho TL, et al. CALR and ASXL1 mutations-based molecular prognostication in primary myelofibrosis:an international study of 570 patients. Leukemia 2014.
11. Guglielmelli P, Nangalia J, Green AR, et al. CALR mutations in myeloproliferative neoplasms: Hidden behind the reticulum. American journal of hematology 2014.
12. Tefferi A, Lasho TL, Finke CM, et al. CALR vs JAK2 vs MPL-mutated or triple-negative myelofibrosis:clinical, cytogenetic and molecular comparisons. Leukemia 2014.
13. Panagiota V, Thol F, Markus B, et al. Prognostic effect of calreticulin mutations in patients with myelofibrosis after allogeneic hematopoietic stem cell transplantation. Leukemia 2014.
14. Chi J, Nicolaou KA, Nicolaidou V, et al. Calreticulin gene exon 9 frameshift mutations in patients with thrombocytosis. Leukemia 2013.
15. Levine RL. Another piece of the myeloproliferative neoplasms puzzle. The New England journal of medicine 2013;369:2451-2452.
16. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
17. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
18. Swerdllow S, Campo E, Harris NL. WHO classification of tumours of haematopoietic and lymphoid tissues. France:IARC Press,2008; 2008.
19. Manoharan A, Horsley R, Pitney WR. The reticulin content of bone marrow in acute leukaemia in adults. British journal of haematology 1979;43:185-190.
20. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
21. Mustjoki S, Borze I, Lasho TL, et al. JAK2V617F mutation and spontaneous megakaryocytic or erythroid colony formation in patients with essential thrombocythaemia (ET) or polycythaemia vera (PV). Leukemia research 2009;33:54-59.
22. Carobbio A, Finazzi G, Antonioli E, et al. JAK2V617F allele burden and thrombosis:a direct comparison in essential thrombocythemia and polycythemia vera. Experimental hematology 2009;37:1016-1021.
23. Brecqueville M, Rey J, Bertucci F, et al. Mutation analysis of ASXL1, CBL, DNMT3A, IDH1, IDH2, JAK2, MPL, NF1, SF3B1, SUZ12, and TET2 in myeloproliferative neoplasms. Genes, chromosomes & cancer 2012;51:743-755.
24. Green MR, Gentles AJ, Nair RV, et al. Hierarchy in somatic mutations arising during genomic evolution and progression of follicular lymphoma. Blood 2013; 121:1604-1611.
25. Lasho TL, Elliott MA, Pardanani A, et al. CALR mutation studies in chronic neutrophilic leukemia. American journal of hematology 2014.
26. Vannucchi AM, Rotunno G, Bartalucci N, et al. Calreticulin mutation-specific immunostaining in myeloproliferative neoplasms:pathogenetic insight and diagnostic value. Leukemia 2014.
27. Tefferi A, Lasho TL, Finke C, et al. Type 1 vs type 2 calreticulin mutations in primary myelofibrosis:differences in phenotype and prognostic impact. Leukemia 2014.
1. Mesa RA, Silverstein, M.N., Jacobsen, S.J., Wollan, P.C., and Tefferi, A. Population-based incidence and survival figures in essential thrombocythemia and agnogenic myeloid metaplasia: an Olmsted County Study. Am J Hematol 1999;61:10-15.
2. Hasle H. Incidence of essential thrombocythaemia in children. British journal of haematology 2000;110:751.
3. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
4. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
5. Randi ML, Putti MC, Scapin M, et al. Pediatric patients with essential thrombocythemia are mostly polyclonal and V617FJAK2 negative. Blood 2006;108:3600-3602.
6. El-Moneim AA, Kratz CP, Boll S, et al. Essential versus reactive thrombocythemia in children: retrospective analyses of 12 cases. Pediatric blood & cancer 2007;49:52-55.
7. Teofili L, Giona F, Martini M, et al. Markers of myeloproliferative diseases in childhood polycythemia vera and essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2007;25:1048-1053.
8. Teofili L, Giona F, Martini M, et al. The revised WHO diagnostic criteria for Ph-negative myeloproliferative diseases are not appropriate for the diagnostic screening of childhood polycythemia vera and essential thrombocythemia. Blood 2007;110:3384-3386.
9. Nakatani T, Imamura T, Ishida H, et al. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia, Pediatric blood & cancer 2008;51:802-805.
10. Veselovska J PD, Pekova S, Horvathova M, Solna R, Cmejlova J, Cmejla R, Belickova M, Mihal V, Stary J, Divoky V. Most pediatric patients with essential thrombocythemia show hypersensitivity to erythropoietin in vitro, with rare JAK2 V617F-positive erythroid colonies. Leukemia research 2008;32:369-377.
11. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
12. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
13. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
14. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
15. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
16. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
17. Langabeer SE, Haslam K, McMahon C. CALR mutations are rare in childhood essential thrombocythemia. Pediatric blood & cancer 2014.
18. Manoharan A, Horsley R, Pitney WR. The reticulin content of bone marrow in acute leukaemia in adults. British journal of haematology 1979;43:185-190.
19. Barosi G, Mesa RA, Thiele J, et al. Proposed criteria for the diagnosis of post-polycythemia vera and post-essential thrombocythemia myelofibrosis:a consensus statement from the International Working Group for Myelofibrosis Research and Treatment. Leukemia 2008;22:437-438.
20. Barosi G, Besses C, Birgegard G, et al. A unified definition of clinical resistance/intolerance to hydroxyurea in essential thrombocythemia:results of a consensus process by an international working group. Leukemia 2007;21:277-280.
21. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
22. McNally RJ, Rowland D, Roman E, et al. Age and sex distributions of hematological malignancies in the U.K. Hematological oncology 1997;15:173-189.
23. Frewin R, Dowson A. Headache in essential thrombocythaemia. International journal of clinical practice 2012;66:976-983.
24. Kesler A, Ellis MH, Manor Y, et al. Neurological complications of essential thrombocytosis (ET). Acta neurologica Scandinavica 2000; 102:299-302.
25. Cassidy EM, Tomkins E, Dinan T, et al. Central 5-HT receptor hypersensitiviry in migraine without aura. Cephalalgia:an international journal of headache 2003;23:29-34.
26. Hanington E. Migraine:the platelet hypothesis after 10 years. Biomedicine & pharmacotherapy= Biomedecine& pharmacotherapie 1989;43:719-726.
27. Izzati-Zade KF. The role of serotonin in the pathogenesis and clinical presentations of migraine attacks. Neuroscience and behavioral physiology 2008;38:501-505.
28. Cesar JM, de Miguel D, Garcia Avello A, et al. Platelet dysfunction in primary thrombocythemia using the platelet function analyzer, PFA-100. American journal of clinical pathology 2005;123:772-777.
29. Bellucci S, Michiels JJ. Spontaneous proliferative megakaryocytopoiesis and platelet hyperreactivity in essential thrombocythemia:is thrombopoietin the link? Annals of hematology 2000;79:51-58.
30. Dos Santos LC, Ribeiro JC, Silva NP, et al. Cytogenetics, JAK2 and MPL mutations in polycythemia vera, primary myelofibrosis and essential thrombocythemia. Revista brasileira de hematologia e hemoterapia 2011;33:417-424.
31. Gangat N, Tefferi A, Thanarajasingam G, et al. Cytogenetic abnormalities in essential thrombocythemia:prevalence and prognostic significance. European journal of haematology 2009;83:17-21.
32. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
33. Hernandez-Boluda JC, Alvarez-Larran A, Gomez M, et al. Clinical evaluation of the European LeukaemiaNet criteria for clinicohaematological response and resistance/intolerance to hydroxycarbamide in essential thrombocythaemia. British journal of haematology 2011;152:81-88.
34. Leung AK, Robson WL, Liu EK, et al. Melanonychia striata in Chinese children and adults. International journal of dermatology 2007;46:920-922.
35. Wiechert A, Reinhard G, Tuting T, et al. Multiple skin cancers in a patient treated with hydroxyurea. Der Hautarzt; Zeitschrift fur Dermatologie, Venerologie, und verwandte Gebiete 2009;60:651-652,654.
36. Murray NP, Tapia P, Porcell J, et al. Acquired melanonychia in Chilean patients with essential thrombocythemia treated with hydroxyurea:a report of 7 clinical cases and review of the literature. ISRN dermatology 2013;2013:325246.
37. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
38. Kinney TR HR, O'Branski EE, Ohene-Frempong K, Wang W, Daeschner C, Vichinsky E, Redding-Lallinger R, Gee B, Platt OS, Ware RE. Safety of hydroxyurea in children with sickle cell anemia:results of the HUG-KIDS study, a phase Ⅰ/Ⅱ trial. Pediatric Hydroxyurea Group. Blood 1999;94:1550-1554.
39. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
40. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
41. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012;120:1197-1201.
42. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
43. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
44. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
45. Finazzi G, Carobbio A, Thiele J, et al. Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria. Leukemia 2012;26:716-719.
46. Yang RC, Qian LS. Essential thrombocythaemia in children:a report of nine cases. British journal of haematology 2000;110:1009-1010.
47. Teofili L, Cenci T, Martini M, et al. The mutant JAK2 allele burden in children with essential thrombocythemia. British journal of haematology 2009;145:430-432.
48. Gangat N, Wolanskyj AP, Tefferi A. Abdominal vein thrombosis in essential thrombocythemia: prevalence, clinical correlates, and prognostic implications. European journal of haematology 2006;77:327-333.
49. Johnson M, Gernsheimer T, Johansen K. Essential thrombocytosis:underemphasized cause of large-vessel thrombosis. Journal of vascular surgery 1995;22:443-447; discussion 448-449.
50. Elliott MA, Tefferi A. Thrombosis and haemorrhage in polycythaemia vera and essential thrombocythaemia. British journal of haematology 2005;128:275-290.
51. Mossier C, Kerbl R, Wagner T, et al. Portal vein thrombosis in a 17-year-old female adolescent with essential thrombocytosis. Pediatric hematology and oncology 1997; 14:457-462.
1. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
2. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008;112:844-847.
3. Brecqueville M, Rey J, Bertucci F, et al. Mutation analysis of ASXL1, CBL, DNMT3A, IDH1, IDH2, JAK2, MPL, NF1, SF3B1, SUZ12, and TET2 in myeloproliferative neoplasms. Genes, chromosomes & cancer 2012;51:743-755.
4. Klampfl T, Gisslinger H, Harutyunyan AS, et al. Somatic mutations of calreticulin in myeloproliferative neoplasms. The New England journal of medicine 2013;369:2379-2390.
5. Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. The New England journal of medicine 2013;369:2391-2405.
6. Rumi E, Pietra D, Ferretti V, et al. JAK2 or CALR mutation status defines subtypes of essential thrombocythemia with substantially different clinical course and outcomes. Blood 2013.
7. Rotunno G, Mannarelli C, Guglielmelli P, et al. Impact of Calreticulin Mutations on Clinical and Hematological Phenotype and Outcome in Essential Thrombocythemia. Blood 2013.
8. Farruggia P, D'Angelo P, La Rosa M, et al. MPL W515L mutation in pediatric essential thrombocythemia. Pediatric blood & cancer 2013;60:E52-54.
9. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
10. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
11. Lambert MP, Jiang J, Batra V, et al. A novel mutation in MPL (Y252H) results in increased thrombopoietin sensitivity in essential thrombocythemia. American journal of hematology 2012;87:532-534.
12. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
13. Reuther GW. Recurring mutations in myeloproliferative neoplasms alter epigenetic regulation of gene expression. American journal of cancer research 2011;1:752-762.
14. Hou Y, Song L, Zhu P, et al. Single-cell exome sequencing and monoclonal evolution of a JAK2-negative myeloproliferative neoplasm. Cell 2012;148:873-885.
15. Greenberg PL. Molecular and genetic features of myelodysplastic syndromes. International journal of laboratory hematology 2012;34:215-222.
16. Tefferi A. Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms:JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1. Leukemia 2010;24:1128-1138.
17. Larsson CA, Cote G, Quintas-Cardama A. The changing mutational landscape of acute myeloid leukemia and myelodysplastic syndrome. Molecular cancer research:MCR 2013; 11:815-827.
18. Hermouet S, Vilaine M. The JAK246/1 haplotype:a marker of inappropriate myelomonocytic response to cytokine stimulation, leading to increased risk of inflammation, myeloid neoplasm, and impaired defense against infection? Haematologica 2011;96:1575-1579.
19. Zhang X, Hu T, Wu Z, et al. The JAK246/1 haplotype is a risk factor for myeloproliferative neoplasms in Chinese patients. International journal of hematology 2012;96:611-616.
20. Kondo T, Okabe M, Sanada M, et al. Familial essential thrombocythemia associated with one-base deletion in the 5'-untranslated region of the thrombopoietin gene. Blood 1998;92:1091-1096.
21. Ding J, Komatsu H, Iida S, et al. The Asn505 mutation of the c-MPL gene, which causes familial essential thrombocythemia, induces autonomous homodimerization of the c-Mpl protein due to strong amino acid polarity. Blood 2009;114:3325-3328.
22. Etheridge SL, Cosgrove ME, Sangkhae V, et al. A novel activating, germline JAK2 mutation, JAK2R564Q, causes familial essential thrombocytosis. Blood 2014;123:1059-1068.
23. Marty C, Saint-Martin C, Pecquet C, et al. Germ-line JAK2 mutations in the kinase domain are responsible for hereditary thrombocytosis and are resistant to JAK2 and HSP90 inhibitors. Blood 2014;123:1372-1383.
24. Tefferi A. JAK inhibitors for myeloproliferative neoplasms:clarifying facts from myths. Blood 2012;119:2721-2730.
25. Papaemmanuil E, Gerstung M, Malcovati L, et al. Clinical and biological implications of driver mutations in myelodysplastic syndromes. Blood 2013;122:3616-3627; quiz 3699.
26. Jones AV, Cross NC. Inherited predisposition to myeloproliferative neoplasms. Therapeutic advances in hematology 2013;4:237-253.
1. Cervantes F, Passamonti F, Barosi G. Life expectancy and prognostic factors in the classic BCR/ABL-negative myeloproliferative disorders. Leukemia 2008;22:905-914.
2. Tefferi A, Vardiman JW. Classification and diagnosis of myeloproliferative neoplasms:the 2008 World Health Organization criteria and point-of-care diagnostic algorithms. Leukemia 2008;22:14-22.
3. Mesa RA, Silverstein, M.N., Jacobsen, S.J., Wollan, P.C., and Tefferi, A. Population-based incidence and survival figures in essential thrombocythemia and agnogenic myeloid metaplasia: an Olmsted County Study. Am J Hematol 1999;61:10-15.
4. Hasle H. Incidence of essential thrombocythaemia in children. British journal of haematology 2000;110:751.
5. Giona F, Teofili L, Moleti ML, et al. Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis:clinical and biologic features, treatment, and long-term outcome. Blood 2012;119:2219-2227.
6. Alvarez-Larran A, Cervantes F, Bellosillo B, et al. Essential thrombocythemia in young individuals:frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients. Leukemia 2007;21:1218-1223.
7. Passamonti F, Rumi E, Arcaini L, et al. Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia:a study of 605 patients. Haematologica 2008;93:1645-1651.
8. Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 World Health Organization-defined essential thrombocythemia at diagnosis:a study by the International Working Group on Myelofibrosis Research and Treatment. Blood 2012; 120:1197-1201.
9. Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis:an international study. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:3179-3184.
10. Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia:an international study of 891 patients. Blood 2011;117:5857-5859.
11. Campbell PJ, MacLean C, Beer PA, et al. Correlation of blood counts with vascular complications in essential thrombocythemia:analysis of the prospective PT1 cohort. Blood 2012;120:1409-1411.
12. Finazzi G, Carobbio A, Thiele J, et al. Incidence and risk factors for bleeding in 1104 patients with essential thrombocythemia or prefibrotic myelofibrosis diagnosed according to the 2008 WHO criteria. Leukemia 2012;26:716-719.
13. Veselovska J PD, Pekova S, Horvathova M, Solna R, Cmejlova J, Cmejla R, Belickova M, Mihal V, Stary J, Divoky V. Most pediatric patients with essential thrombocythemia show hypersensitivity to erythropoietin in vitro, with rare JAK2 V617F-positive erythroid colonies. Leukemia research 2008;32:369-377.
14. Randi ML, Putti MC, Scapin M, et al. Pediatric patients with essential thrombocythemia are mostly polyclonal and V617FJAK2 negative. Blood 2006;108:3600-3602.
15. Teofili L, Giona F, Martini M, et al. Markers of myeloproliferative diseases in childhood polycythemia vera and essential thrombocythemia. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2007;25:1048-1053.
16. Yang RC, Qian LS. Essential thrombocythaemia in children:a report of nine cases. British journal of haematology 2000;110:1009-1010.
17. Teofili L, Cenci T, Martini M, et al. The mutant JAK2 allele burden in children with essential thrombocythemia. British journal of haematology 2009; 145:430-432.
18. Nakatani T, Imamura T, Ishida H, et al. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia. Pediatric blood & cancer 2008;51:802-805.
19. Teofili L, Giona F, Martini M, et al. The revised WHO diagnostic criteria for Ph-negative myeloproliferative diseases are not appropriate for the diagnostic screening of childhood polycythemia vera and essential thrombocythemia. Blood 2007;110:3384-3386.
20. Baxter EJ, Scott LM, Campbell PJ, et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054-1061.
21. El-Moneim AA, Kratz CP, Boll S, et al. Essential versus reactive thrombocythemia in children: retrospective analyses of 12 cases. Pediatric blood & cancer 2007;49:52-55.
22. Ismael O, Shimada A, Hama A, et al. Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children. Pediatric blood & cancer 2012;59:530-535.
23. Campbell PJ, Scott LM, Buck G, et al. Definition of subtypes of essential thrombocythaemia and relation to polycythaemia vera based on JAK2 V617F mutation status:a prospective study. Lancet 2005;366:1945-1953.
24. Farruggia P, D'Angelo P, La Rosa M, et al. MPL W515L mutation in pediatric essential thrombocythemia. Pediatric blood & cancer 2013;60:E52-54.
25. Lambert MP, Jiang J, Batra V, et al. A novel mutation in MPL (Y252H) results in increased thrombopoietin sensitivity in essential thrombocythemia. American journal of hematology 2012;87:532-534.
26. Pardanani AD, Levine RL, Lasho T, et al. MPL515 mutations in myeloproliferative and other myeloid disorders:a study of 1182 patients. Blood 2006;108:3472-3476.
27. Beer PA, Campbell PJ, Scott LM, et al. MPL mutations in myeloproliferative disorders:analysis of the PT-1 cohort. Blood 2008;112:141-149.
28. Vannucchi AM, Antonioli E, Guglielmelli P, et al. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia. Blood 2008; 112:844-847.
29. Kondo T, Okabe M, Sanada M, et al. Familial essential thrombocythemia associated with one-base deletion in the 5'-untranslated region of the thrombopoietin gene. Blood 1998;92:1091-1096.
30. Ding J, Komatsu H, Iida S, et al. The Asn505 mutation of the c-MPL gene, which causes familial essential thrombocythemia, induces autonomous homodimerization of the c-Mpl protein due to strong amino acid polarity. Blood 2009;114:3325-3328.
31. Etheridge SL, Cosgrove ME, Sangkhae V, et al. A novel activating, germline JAK2 mutation, JAK2R564Q, causes familial essential thrombocytosis. Blood 2014;123:1059-1068.
32. Marty C, Saint-Martin C, Pecquet C, et al. Germ-line JAK2 mutations in the kinase domain are responsible for hereditary thrombocytosis and are resistant to JAK2 and HSP90 inhibitors. Blood 2014;123:1372-1383.
33. Cilloni D, Carturan S, Gottardi E, et al. Usefulness of the quantitative assessment of PRV-1 gene expression for the diagnosis of polycythemia vera and essential thrombocythemia patients. Blood 2004;103:2428.
34. Johansson P, Ricksten A, Wennstrom L, et al. Increased risk for vascular complications in PRV-1 positive patients with essential thrombocythaemia. British journal of haematology 2003;123:513-516.
35. Vannucchi AM, Grossi A, Pancrazzi A, et al. PRV-1, erythroid colonies and platelet Mpl are unrelated to thrombosis in essential thrombocythaemia. British journal of haematology 2004;127:214-219.
36. Gale RE, Allen AJ, Nash MJ, et al. Long-term serial analysis of X-chromosome inactivation patterns and JAK2 V617F mutant levels in patients with essential thrombocythemia show that minor mutant-positive clones can remain stable for many years. Blood 2007;109:1241-1243.
37. Michiels JJ, Juvonen E. Proposal for revised diagnostic criteria of essential thrombocythemia and polycythemia vera by the Thrombocythemia Vera Study Group. Seminars in thrombosis and hemostasis 1997;23:339-347.
38. Vardiman JW, Harris NL, Brunning RD. The World Health Organization (WHO) classification of the myeloid neoplasms. Blood 2002;100:2292-2302.
39. Chan GC, Ma SK, Ha SY, et al. Childhood essential thrombocythaemia without evidence of myeloproliferation:how many investigations should be done? British journal of haematology 2000;110:1002.
40. Dame C, Sutor AH. Primary and secondary thrombocytosis in childhood. British journal of haematology 2005;129:165-177.
41. Chiarello P, Magnolia M, Rubino M, et al. Thrombocytosis in children. Minerva pediatrica 2011;63:507-513.
42. Dror Y, Blanchette VS. Essential thrombocythaemia in children. British journal of haematology 1999; 107:691-698.
43. Teofili L, Giona F, Torti L, et al. Hereditary thrombocytosis caused by MPLSer505Asn is associated with a high thrombotic risk, splenomegaly and progression to bone marrow fibrosis. Haematologica 2010;95:65-70.
44. Liu K, Kralovics R, Rudzki Z, et al. A de novo splice donor mutation in the thrombopoietin gene causes hereditary thrombocythemia in a Polish family. Haematologica 2008;93:706-714.
45. Teofili L LL. Advances in understanding the pathogenesis of familial thrombocythaemia. British journal of haematology 2011;152:701-712.
46. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms:critical concepts and management recommendations from European LeukemiaNet. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29:761-770.
47. Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an International Prognostic Score of thrombosis in World Health Organization-essential thrombocythemia (IPSET-thrombosis). Blood 2012;120:5128-5133; quiz 5252.
48. Harrison CN, Bareford D, Butt N, et al. Guideline for investigation and management of adults and children presenting with a thrombocytosis. British journal of haematology 2010;149:352-375.
49. Bennett CL, Starko KM, Thomsen HS, et al. Linking drugs to obscure illnesses:lessons from pure red cell aplasia, nephrogenic systemic fibrosis, and Reye's syndrome, a report from the Southern Network on Adverse Reactions (SONAR). Journal of general internal medicine 2012;27:1697-1703.
50. Cervantes F. Management of essential thrombocythemia. Hematology/the Education Program of the American Society of Hematology American Society of Hematology Education Program 2011;2011:215-221.
51. Tefferi A. Myeloproliferative neoplasms 2012:the John M. Bennett 80th birthday anniversary lecture. Leukemia research 2012;36:1481-1489.
52. Barbui T. How to manage children and young adults with myeloproliferative neoplasms. Leukemia 2012;26:1452-1457.
53. Cortelazzo S, Finazzi G, Ruggeri M, et al. Hydroxyurea for patients with essential thrombocythemia and a high risk of thrombosis. The New England journal of medicine 1995;332:1132-1136.
54. Finazzi G, Ruggeri M, Rodeghiero F, et al. Efficacy and safety of long-term use of hydroxyurea in young patients with essential thrombocythemia and a high risk of thrombosis. Blood 2003;101:3749.
55. Radaelli F, Onida F, Rossi FG, et al. Second malignancies in essential thrombocythemia (ET):a retrospective analysis of 331 patients with long-term follow-up from a single institution. Hematology 2008;13:195-202.
56. Bjorkholm M DA, Hultcrantz M, Kristinsson SY, Ekstrand C, Goldin LR, Andreasson B, Birgegard G, Linder O, Malm C, Markevarn B, Nilsson L, Samuelsson J, Granath F, Landgren O. Treatment-related risk factors for transformation to acute myeloid leukemia and myelodysplastic syndromes in myeloproliferative neoplasms. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2011;29.
57. Kinney TR HR, O'Branski EE, Ohene-Frempong K, Wang W, Daeschner C, Vichinsky E, Redding-Lallinger R, Gee B, Platt OS, Ware RE. Safety of hydroxyurea in children with sickle cell anemia:results of the HUG-KIDS study, a phase Ⅰ/Ⅱ trial. Pediatric Hydroxyurea Group. Blood 1999;94:1550-1554.
58. Quintas-Cardama A, Kantarjian H, Manshouri T, et al. Pegylated interferon alfa-2a yields high rates of hematologic and molecular response in patients with advanced essential thrombocythemia and polycythemia vera. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2009;27:5418-5424.
59. Mazzucconi MG, Redi R, Bernasconi S, et al. A long-term study of young patients with essential thrombocythemia treated with anagrelide. Haematologica 2004;89:1306-1313.
60. Gisslinger H, Gotic M, Holowiecki J, et al. Anagrelide compared with hydroxyurea in WHO-classified essential thrombocythemia:the ANAHYDRET Study, a randomized controlled trial. Blood 2013;121:1720-1728.
61. Hernandez-Boluda JC, Pereira A, Cervantes F, et al. Clinical evaluation of the European LeukemiaNet response criteria in patients with essential thrombocythemia treated with anagrelide. Annals of hematology 2013.
62. Harrison CN, Campbell PJ, Buck G, et al. Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia. The New England journal of medicine 2005;353:33-45.
63. Campbell PJ, Bareford D, Erber WN, et al. Reticulin accumulation in essential thrombocythemia: prognostic significance and relationship to therapy. Journal of clinical oncology:official journal of the American Society of Clinical Oncology 2009;27:2991-2999.