器官移植实验室人类白细胞抗原抗体检测方案研究

Exploration and practice of HLA antibody detection strategy at organ transplantation laboratoryies

目的比较Luminex筛查法(LMX)及酶联免疫吸附测定(ELISA)法检测人类白细胞抗原(HLA)抗体的检测性能,为器官移植实验室选择合理HLA抗体检测方案提供参考。方法对124例连续送检的样本同时采用单抗原微珠法(single antigen-bead assay,SAB)、ELISA及LMX方法检测,分析检测结果的差异。以SAB检测为参考方法,分析两种筛查方法的敏感性和特异性,设置P<0.05为差异有统计学意义。结果ELISA与LMX筛查方法检测HLA抗体的敏感性均较低,HLAⅠ类分别为34.4%和31.3%,HLAⅡ类分别为29.7%和51.3%,特异性均较高,HLAⅠ类均为98.9%,HLAⅡ类分别为100%和91.9%。在124例样本中,SAB(+)LMX(-)ELISA(-)的例数为17,而SAB(-)LMX(+)ELISA(+)的例数为0,提示有相当一部分筛查存在漏检的可能性。在SAB(+)ELISA(-)LMX(-)的情况中,SAB检测的中位荧光强度(MFI)值分布范围为750~7000。结论由于两种筛查方法的敏感性均较低,对于先做筛查,检测为阳性后再进行特异性抗体检测的方案存在较大抗体漏检的风险,应给予重视,尤其对于受者有致敏史的阴性结果,应考虑采用SAB或其他检测方法给与复核。而初检时直接采用敏感性和特异更高的SAB法可提高检测的准确性,同时可以结合SAB检测的MFI值,确定是否再辅以其他检测方法来验证SAB结果。

Objective To compare the results of three detection methods,single antigen-bead assay(SAB),Luminex screening assay(LMX),and ELISA assay for detecting HLA antibody,and compares the two screening methods,LMX and ELISA with SAB detection as a reference method to provide a reference for organ transplantation laboratories to choose a reasonable HLA antibody test strategy.Methods A lot of 124 consecutive samples were tested using SAB,ELISA,and LMX methods at the same time,and analyze the differences of these results.SAB testing was used as a reference method to analyze the sensitivity and specificity of the two screening assays.Chi-square analysis was used to compare the two methods,and P<0.05 was considered statistically significant.Results Both ELISA and LMX methods showed low sensitivity of 34.4%and 31.3%for HLA class I,and 29.7%and 51.3%for classⅡ.Otherwise,the specificity of the ELISA and LMX method was much higher.For class,I both was 98.9%,and for classⅡwere 100%and 91.9%respectively.Out of 124 samples,the number of SAB(+)ELISA(-)LMX(-)results was 17,and SAB(-)ELISA(+)LMX(+)results was zero indicating that there were considerably screening assays probably with missed detection.In the cases of SAB(+)ELISA(-)LMX(-),the distribution of MFI value of SAB assay ranges from 750 to 7000.Conclusions Because the sensitivity of the two screening methods is relatively low,there is a greater risk of missed antibody detection in the scheme of testing for specific antibodies after the screening test is positive.This should be paid attention to,especially for patients with a history of sensitization.For negative screening test results,SAB or other assays should be considered to check the result.It could provide more accurate results when SAB which is recognized as higher sensitivity and specificity is directly used as an initial test.At the same time,the MFI value of the SAB test can serve as an indicator to determine whether to add other assays to check the ASB result.