In moderate-to-severe asthma patients monitoring exhaled nitric oxide during exacerbation is not a good predictor of spirometric response to oral corticosteroid

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• 作者：Arthur F. Gelb ; MD^a ; ^b ; ^{afgelb@msn.com} ; Roxanna Moridzadeh^a ; ^&lowast ; ; Deepak H. Singh ; BS^a ; ^&lowast ; ; Christine Fraser ; RCP ; CPFT^a ; ^&lowast ; ; Steven C. George ; MD ; PhD^c
• 关键词：Asthma ; exhaled nitric oxide ; asthma mechanisms
• 刊名：Journal of Allergy and Clinical Immunology
• 出版年：2012
• 期刊代码：158_00916749
• 类别：med
• 出版时间：June, 2012
• 卷：129
• 期：6
• 页码：1491-1498
• 文件大小：360 K

摘要

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Background

The importance of monitoring exhaled nitric oxide (NO) in asthma remains controversial.

Objective

To measure exhaled NO, postnebulized albuterol/ipratropium spirometry, and Asthma Control Test (ACT) during asthma exacerbation requiring 8- to 10-day tapering oral corticosteroid in nonsmoking patients with moderate-to-severe asthma on moderate-dose inhaled corticosteroid and long-acting 尾₂-agonist but not maintenance oral corticosteroid.

Methods

After measuring the fraction of exhaled NO (Feno [ppb]) at 50, 100, 150, and 200 mL/s, the total Feno at 50 mL/s (ppb), large central airway NO flux (J鈥?sub>awNO [nL/s]), and peripheral small airway/alveolar NO concentration (C_ANO [ppb]) were calculated and corrected for NO axial back-diffusion. Outpatient exacerbation required the patient with asthma to be afebrile with normal chest x-ray and white blood cell count.

Results

Group 1 included 17 patients (6 men) with asthma, age 52 卤 12 years, studied at baseline, during 18 exacerbations with abnormal Feno at 50 mL/s, J鈥?sub>awNO, and/or C_ANO, and post 8- to 10-day tapering 40 mg prednisone (recovery). Baseline: IgE, 332 卤 243 K渭; total blood eosinophils, 304 卤 266 cells/渭L; body mass index, 28 卤 6; ACT, 16 to 19; and FEV₁, 2.5 卤 0.7 L (86%卤 20%predicted); exacerbation: FEV₁, 1.7 卤 0.4 L (60%卤 17%) (P聽< .001); recovery: FEV₁, 2.5 卤 0.7 L (85%卤 13%) (P聽< .001). Group 2 included 11 (7 men) similarly treated patients with asthma, age 49 卤 14 years, studied at baseline, during 15 exacerbations with normal Feno at 50 mL/s, J鈥?sub>awNO, and C_ANO. Baseline: IgE, 307 卤 133 K渭; total blood eosinophils, 296 卤 149 cells/渭L; body mass index, 28 卤 6; ACT, 16 to 19; and FEV₁, 2.7 卤 0.9 L (71%卤 12%predicted); exacerbation: FEV₁, 1.7 卤 0.6 L (54%卤 19%) (P聽< .006); recovery: FEV₁, 2.7 卤 0.9 L (70%卤 14%) (P聽= .002). On comparing group 1 versus group 2, there was no significant difference for baseline IgE, eosinophils, body mass index, and ACT and similar significant (鈮?006) decrease from baseline in FEV₁ (L) during exacerbation and similar increase (鈮?006) at recovery.

Conclusions

Increased versus normal exhaled NO during outpatient exacerbation in patients with moderate-to-severe asthma on inhaled corticosteroid and long-acting 尾₂-agonist but not maintenance oral corticosteroid does not preclude a robust clinical and spirometric response to tapering oral prednisone.