The occurrence of acute antibody-mediated rejection (ABMR) is higher in flow cytometric crossmatch (FCXM)-positive patients despite desensitization. Accumulating evidence suggests a correlation between the complement-binding ability of donor-specific antibodies (DSAs) and the risk of ABMR. Here, we investigated the correlation between complement C3d-fixing ability of preformed DSA and ABMR risk, the efficacy of a desensitization protocol for patients with C3d-fixing DSA, and the risk of ABMR in 21 DSA- and FCXM-positive patients. We retrospectively analyzed the C3d-fixing ability and mean fluorescence intensity (MFI) of preformed DSA before and after desensitization. Six patients had non-C3d-fixing DSA and 15 had C3d-fixing DSA. The presence of C3d-fixing DSA before desensitization was correlated with the incidence of acute ABMR within 1 year after transplantation (p = .04) and chronic ABMR (p = .03). Moreover, the MFI of preformed DSA differed between responder and non-responder C3d-fixing DSA after desensitization (p < .0001). The C3d-fixing ability of preformed DSA with low MFI disappeared after desensitization. These results indicate that measuring DSA C3d-fixing ability may identify patients with a high risk of ABMR, especially before desensitization.

Clinical trial notation

UMIN Clinical Trials Registry (UMIN-CTR) number: UMIN000033449.

中文翻译：

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C3d固定，预先形成的供体特异性抗体在交叉匹配阳性活体肾脏移植中的预后价值。

尽管脱敏，流式细胞仪交叉匹配（FCXM）阳性患者中急性抗体介导排斥（ABMR）的发生率较高。越来越多的证据表明供体特异性抗体（DSA）的补体结合能力与ABMR风险之间存在相关性。在这里，我们调查了预先形成的DSA的补体C3d固定能力与ABMR风险，脱敏方案对C3d固定DSA患者的疗效以及21名DSA和FCXM阳性患者的ABMR风险之间的相关性。我们回顾性分析了脱敏前后DSA的C3d固定能力和平均荧光强度（MFI）。6名非C3d固定DSA患者和15名C3d固定DSA患者。p  = .04）和慢性ABMR（p  = .03）。此外，脱敏后，在响应者和非响应者固定C3d的DSA之间，预先形成的DSA的MFI有所不同（p  <.0001）。脱敏后，低MFI的预形成DSA的C3d固定能力消失。这些结果表明，测量DSA C3d固定能力可能会识别出具有ABMR高风险的患者，尤其是在脱敏之前。

临床试验符号

UMIN临床试验注册中心（UMIN-CTR）编号：UMIN000033449。