Low median fluorescence intensity could be a nonsafety concept of immunologic risk evaluation in patients with shared molecular eplets in kidney transplantation

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• 作者：Alexandre Bosch^a ; Santiago Llorente^b ; Julio A. Diaz^a ; Gema Salgado^a ; Manuela Ló ; pez^a ; Francisco Boix^a ; Ruth Ló ; pez-Herná ; ndez^a ; Marí ; a J. Gonzá ; lez-Soriano^b ; José ; A. Campillo^a ; ^c ; Marí ; a R. Moya-Quiles^a ; ^c ; Noelia Perez-Lopez^a ; Alfredo Minguela^a ; ^c ; Luisa Jimeno^b ; Marí ; a R. Á ; lvarez-Ló ; pez^a ; ^c ; Manuel Muro^a ; ^c ; ^{manuel.muro@carm.es}
• 关键词：Kidney transplant ; Median fluorescence intensity ; Epitopes ; Cross-matching ; HLA antibodies
• 刊名：Human Immunology
• 出版年：2012
• 期刊代码：75_01988859
• 类别：bio
• 出版时间：May, 2012
• 卷：73
• 期：5
• 页码：522-525
• 文件大小：437 K

摘要

Human leukocyte antigen (HLA) antibodies are usually 鈥渆pitope鈥?and not 鈥渁ntigen鈥?specific. This work presents an interesting case concerning Luminex median fluorescence intensity (MFI) levels in antibodies considered low risk (<1,000), but producing humoral rejection. These low-titer antibodies could play an important role in transplantation. A 42-year-old woman was retransplanted with a deceased donor with negative complement-dependent cytotoxicity cross-matching. Our patient was pretransplant (PrT) sensitized to HLA antigens (single antigens (SA) = 31%) for 1 previous transplant. Thus, the formerly detected sensitized antigens were A32, A30, A31, cross-reacting group 5C, and DQ3 with a MFI_max 鈮?4,127. In the posttransplantation period (PTP), the patient exhibited important instability in renal function and we detected an increased SA percentage (61%) with MFI_max = 15,029 (A*32) with other antigens (detected with a low PrT MFI [<1,000]) as anti-A*03 (MFI_max = 13,301) and anti-A*11 (MFI_max = 13,714) specificities. Anti-A*03 was a donor-specific antibody (DSA). Renal biopsy was compatible with humoral rejection. The patient was pulsed with methylprednisolone, plasmapheresis, and intravenous immunoglobulin without improvement. Thus, we added anti-CD20 and the initial clinical response was highly favorable. Biopsies resulted in suggestive rejection reversion. MFI A*03 DSA decreased to 6,908 and later to MFI_max = 5,505. After a 6-month PTP, the patient is well with MFI_max = 3,124. It was possible to define exactly the potential immunizing epitope eplets whose recognition determined the specific antibody production. A*32:01, A*30:01, A*31:01 (detected PrT), A*11:01, and A*03:01 (detected PTP) alleles have several shared eplets (62QE, 70AQS, and 76VGT), with 62QE being the only eplet present on all alleles. In conclusion, low MFI levels in antibodies considered low risk could be important in posttransplant humoral rejection, although the patient's renal function can be restored. Thus, specific shared eplets should always be investigated with respect to previous transplant mismatches.