Department of Pathology, Command hospital (SC), Pune, India.
Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India.
Scand J Immunol. 2021 Jul;94(1):e13048. doi: 10.1111/sji.13048. Epub 2021 May 15.
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.
并非所有抗人类白细胞抗原供体特异性抗体（HLA-DSA）都对肾移植有不良影响。在这种情况下，抗体的 C1q 补体激活能力似乎是区分临床无活性与有害 DSA 的一个重要参数。我们评估了 206 例连续的原发性活体供肾移植受者在移植前和术后第 7、30、90、180 天以及移植物功能障碍时的血清，使用 Luminex 平台上的单抗原珠测定法来定量 HLA-DSA。对 MFI >500 的这些抗体阳性患者进行进一步筛查，以确定 DSA 是否具有 C1q 结合特性。在 18 例抗体阳性患者中，有 14 例具有 MFI 值>5000 的 C1q 结合 DSA。只有 4 例抗体阳性患者没有 C1q 结合 DSA。C1q 测定法检测到的 DSA 的 MFI 值通常比传统 IgG-SAB 测定法至少高 25%。在平均 21.43±8.03 个月的随访期间，14 例 C1q+DSA 患者中有 12 例（85.71%）发生了抗体介导的排斥反应，而在 4 例 C1q-DSA 患者中无一例发生（85.71%比 0%；P =.001）。这些结果表明 C1q+DSA 对肾移植有不良影响，而 C1q-DSA 则没有。
