Ichimaru N, Takayama T, Hirase H, Hisayama Y, Kawamura M, Nakazawa S, Kato T, Abe T, Kaimori J-Y, Imamura R, Nonomura N, Takahara S
Department of Advanced Technology for Transplantation, Osaka University, Suita, Japan.
Department of Laboratory for HLA, Osaka General Medical Center, Osaka, Japan.
Transplant Proc. 2018 May;50(4):1074-1076. doi: 10.1016/j.transproceed.2018.02.051.
Immunocomplex capture fluorescence analysis (ICFA) detects donor-specific antihuman leukocyte antigen (HLA) antibodies (DSA), but the detection sensitivity of HLA class II antibodies using conventional ICFA is as low as 57%. The aim of the study was to improve the detection sensitivity of HLA class II antibodies by ICFA, and compare the ICFA results with the Luminex single-antigen bead test.
Six DSA-negative kidney transplant donors and recipient pairs and 10 HLA class II DSA-positive pairs were included in the study. The detection sensitivity of modified ICFA was compared with conventional ICFA, and the ICFA results were compared with the Luminex single-antigen bead test.
The index value of modified ICFA was higher than that of conventional ICFA. The cutoff value of conventional ICFA was 30,686 (MFI), which was improved to 19,405 using modified ICFA. Regarding the HLA-DQ antibody, 5 samples found to be positive by Luminex single-antigen bead testing were all negative using modified ICFA. The reason for this discrepancy could be related to: (1) the difference in detection sensitivity; (2) the difference in HLA antigen surface expression between naive lymphocytes and synthetic beads; or (3) the structure of synthetic HLA DQ antigen on the Luminex single-antigen beads.
The index value of the modified ICFA was higher than that of conventional ICFA, and the detection sensitivity of HLA class II antibodies was improved by modified ICFA. Further assessment is necessary to clarify the reasons for divergence between ICFA and Luminex single-antigen bead test results.
免疫复合物捕获荧光分析（ICFA）可检测供者特异性抗人白细胞抗原（HLA）抗体（DSA），但使用传统ICFA检测HLAⅡ类抗体的灵敏度低至57%。本研究旨在提高ICFA检测HLAⅡ类抗体的灵敏度，并将ICFA结果与Luminex单抗原珠试验结果进行比较。
本研究纳入6对DSA阴性的肾移植供受者和10对HLAⅡ类DSA阳性的供受者。将改良ICFA的检测灵敏度与传统ICFA进行比较，并将ICFA结果与Luminex单抗原珠试验结果进行比较。
改良ICFA的指数值高于传统ICFA。传统ICFA的临界值为30,686（MFI），改良ICFA将其提高到19,405。对于HLA-DQ抗体，Luminex单抗原珠试验检测为阳性的5个样本，改良ICFA检测均为阴性。这种差异的原因可能与以下因素有关：（1）检测灵敏度的差异；（2）天然淋巴细胞与合成微珠之间HLA抗原表面表达的差异；或（3）Luminex单抗原珠上合成HLA DQ抗原的结构。
改良ICFA的指数值高于传统ICFA，改良ICFA提高了HLAⅡ类抗体的检测灵敏度。有必要进一步评估以阐明ICFA与Luminex单抗原珠试验结果存在差异的原因。
