Not all anti-HLA donor-specific antibodies (HLA-DSAs) are detrimental to renal allograft. In this context, the C1q complement activating ability of antibodies appears to be an important parameter to distinguish clinically inert versus detrimental DSAs. We evaluated sera of 206 consecutive primary live donor renal transplant recipients before transplant and at post-operative day 7, 30, 90, 180 and at the time of graft dysfunction for quantifying HLA-DSAs using single antigen bead assay on a Luminex platform. Patients positive for these antibodies with an MFI >500 were further screened for C1q fixing nature of DSA. Fourteen of the 18 antibody-positive patients had C1q fixing DSA with MFI value >5000. Only 4 antibody-positive patients did not have C1q fixing DSA. The MFI values of DSA detected by C1q assay were generally higher at least by 25% than those detected by the conventional IgG-SAB assay. Twelve of the 14 patients (85.71%) with C1q+ DSA developed antibody-mediated rejection during the mean follow-up period of 21.43 ± 8.03 months as compared to none of the four C1q-negative DSA (85.71% vs 0%; P = .001). These results suggest deleterious effect of C1q+ DSA vis-à-vis C1q-negative DSA on renal allograft.

中文翻译：

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C1q 固定供体特异性抗体对肾移植结果的影响

并非所有抗 HLA 供体特异性抗体 (HLA-DSA) 都对同种异体肾移植有害。在这种情况下，抗体的 C1q 补体激活能力似乎是区分临床惰性和有害 DSA 的重要参数。我们在移植前和术后第 7、30、90、180 天和移植功能障碍时评估了 206 名连续主要活体供肾移植受者的血清，以在 Luminex 平台上使用单抗原珠测定对 HLA-DSA 进行量化。对 MFI > 500 的这些抗体呈阳性的患者进一步筛选 DSA 的 C1q 固定性质。18 名抗体阳性患者中有 14 名具有 C1q 固定 DSA，MFI 值 >5000。只有 4 名抗体阳性患者没有 C1q 固定 DSA。C1q 法检测到的 DSA 的 MFI 值通常比常规 IgG-SAB 法检测的 MFI 值高至少 25%。在 21.43 ± 8.03 个月的平均随访期内，14 名 C1q+ DSA 患者中有 12 名 (85.71%) 出现抗体介导的排斥反应，而四名 C1q 阴性 DSA 患者均未出现抗体介导的排斥反应（85.71% vs 0%；P  = .001）。这些结果表明 C1q+ DSA 相对于 C1q 阴性 DSA 对肾同种异体移植物的有害影响。