Chauhan Rajni, Tiwari Aseem Kumar, Aggarwal Geet, Gowri Suresh L, Kumar Mohit, Bansal Shyam Bihari
Molecular and Transplant Immunology Laboratory, Department of Transfusion Medicine, Medanta-Gurugram, India.
Molecular and Transplant Immunology Laboratory, Department of Transfusion Medicine, Medanta-Gurugram, India.
Transpl Immunol. 2023 Dec;81:101931. doi: 10.1016/j.trim.2023.101931. Epub 2023 Sep 18.
"In solid organ transplantation, the compatibility between recipient and donor relies on testing prior to transplantation as a major determinant for the successful transplant outcomes. This compatibility testing depends on the detection of donor-specific antibodies (DSAs) present in the recipient. Indeed, sensitized transplant candidates are at higher risk of allograft rejection and graft loss compared to non-sensitized individuals. Most of the laboratories in India have adopted test algorithms for the appropriate risk stratification of transplants, namely: 1) donor cell-based flow-cytometric cross-match (FCXM) assay with patient's serum to detect DSAs; 2) HLA-coated beads to detect anti-HLA antibodies; and 3) complement-dependent cytotoxicity crossmatch (CDCXM) with donor cells to detect cytotoxic antibodies. In the risk stratification strategy, laboratories generally accept a DSA median fluorescence index (MFI) of 1000 MFI or lower MFI (low-MFI) as a negative value and clear the patient for the transplant. We present two cases of live-related donor kidney transplants (LDKTs) with low-MFI pre-transplant DSA values who experienced an early acute antibody-mediated rejection (ABMR) as a result of an anamnestic antibody response by DSA against HLA class II antibodies. These results were confirmed by retesting of both pre-transplant and post-transplant archived sera from patients and freshly obtained donor cells. Our examples indicate a possible ABMR in patients with low MFI pre-transplant DSA. Reclassification of low vs. high-risk may be appropriate for sensitized patients with low-MFI DSA."
在实体器官移植中，受体与供体之间的相容性依赖于移植前的检测，这是移植成功结果的主要决定因素。这种相容性检测取决于检测受体中存在的供体特异性抗体（DSA）。事实上，与未致敏个体相比，致敏的移植候选者发生同种异体移植排斥和移植物丢失的风险更高。印度的大多数实验室都采用了检测算法，对移植进行适当的风险分层，即：1）用患者血清进行基于供体细胞的流式细胞术交叉配型（FCXM）检测以检测DSA；2）用包被 HLA 的微珠检测抗 HLA 抗体；3）用供体细胞进行补体依赖细胞毒性交叉配型（CDCXM）检测细胞毒性抗体。在风险分层策略中，实验室通常将 DSA 中位荧光强度（MFI）为 1000 MFI 或更低的 MFI（低 MFI）视为阴性值，并允许患者进行移植。我们报告了两例活体亲属供肾移植（LDKT）病例，其移植前 DSA 值的 MFI 较低，但由于 DSA 对 HLA II 类抗体的回忆性抗体反应而发生了早期急性抗体介导的排斥反应（ABMR）。通过对患者移植前和移植后的存档血清以及新鲜获取的供体细胞进行重新检测，证实了这些结果。我们的例子表明，移植前 DSA 的 MFI 较低的患者可能发生 ABMR。对于 DSA 的 MFI 较低的致敏患者，重新分类低风险与高风险可能是合适的。
