Rani Lekha, Singh Heera, Saikia Biman, Aggarwal Ritu, Kumar Yashwant, Kumar Mahendra, Chhabra Seema, Kumar Manoj, Kumar Bhuvnesh, Kumar Vinkesh, Das Prabir, Sharma Ashish, Ramchandran Raja, Kohli Harbir Singh, Minz Ranjana Walker
Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Department of Renal Transplant Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Transplant Proc. 2023 Jan-Feb;55(1):134-139. doi: 10.1016/j.transproceed.2022.11.007. Epub 2023 Jan 5.
Presence of preformed donor specific antibodies (DSAs) detected by complement-dependent cytotoxicity (CDC-XM) is a strong contraindication for transplant. However, it has limitations including its sensitivity and its inability to distinguish between HLA-specific and other non-HLA-specific antibodies. In this study, we standardized CDC-XM by flow cytometry and determined its relevance by comparing its results with other methods of DSA detection, such as routine CDC-XM, antibody binding assay by flow cytometry (FC-XM), and Luminex-based crossmatch assays, such as Luminex crossmatch (LXM) and virtual crossmatch (VXM).
A total of 79 serum samples were tested for DSAs by the flow cytometric complement-dependent cytotoxicity crossmatch assay (FC-CDC-XM) and then the results of FC-CDC-XM were compared with other detection methods such as CDC-XM, FC-XM, LXM, and VXM.
We found that the FC-CDC-XM assay is more sensitive than routine CDC-XM. Out of total 79 sera, 24 sera were detected positive (T cells positive: 1 case and B cells positive: 23) by FC-CDC-XM as compared with 3 sera using CDC-XM; these 3 sera also showed positivity by FC-CDC-XM. After FC-XM assay, 23 samples were positive by FC-XM and out of these 23 samples, 13 were also positive by FC-CDC-XM. On comparing the FC-CDC-XM results with VXM and LXM, 10 sera of 24 FC-CDC-XM positive had HLA class II antibodies detected on a Luminex platform.
The FC-CDC-XM is a more sensitive and specific method for detection of HLA-specific complement-fixing antibodies than CDC-XM and FC-XM. FC-CDC-XM should be used in tissue-typing laboratories after intra- and inter- laboratory validation.
通过补体依赖细胞毒性试验（CDC-XM）检测到预先存在的供者特异性抗体（DSA）是移植的强烈禁忌证。然而，它存在局限性，包括其敏感性以及无法区分HLA特异性抗体和其他非HLA特异性抗体。在本研究中，我们通过流式细胞术对CDC-XM进行标准化，并通过将其结果与其他DSA检测方法（如常规CDC-XM、流式细胞术抗体结合试验（FC-XM）以及基于Luminex的交叉配型试验，如Luminex交叉配型（LXM）和虚拟交叉配型（VXM））进行比较来确定其相关性。
通过流式细胞术补体依赖细胞毒性交叉配型试验（FC-CDC-XM）对79份血清样本进行DSA检测，然后将FC-CDC-XM的结果与其他检测方法（如CDC-XM、FC-XM、LXM和VXM）进行比较。
我们发现FC-CDC-XM试验比常规CDC-XM更敏感。在总共79份血清中，FC-CDC-XM检测到24份血清呈阳性（T细胞阳性：1例，B细胞阳性：23例），而使用CDC-XM检测到3份血清呈阳性；这3份血清通过FC-CDC-XM检测也呈阳性。在进行FC-XM试验后，23份样本通过FC-XM呈阳性，在这23份样本中，13份通过FC-CDC-XM也呈阳性。将FC-CDC-XM结果与VXM和LXM进行比较时，24份FC-CDC-XM阳性血清中有10份在Luminex平台上检测到HLA II类抗体。
与CDC-XM和FC-XM相比，FC-CDC-XM是检测HLA特异性补体结合抗体更敏感和特异的方法。在进行实验室内部和实验室间验证后，FC-CDC-XM应在组织配型实验室中使用。
