The role of non-HLA autoantibodies in chronic-active antibody-mediated rejection (c-aABMR) of kidney transplants is largely unknown. In this study, the presence and clinical relevance of non-HLA autoantibodies using a recently developed multiplex Luminex-based assay were investigated. Patients with a kidney allograft biopsy at least 6 months after transplantation with a diagnosis of c-aABMR (n = 36) or no rejection (n = 21) were included. Pre-transplantation sera and sera at time of biopsy were tested for the presence of 14 relevant autoantibodies.

A significantly higher signal for autoantibodies against Rho GDP‐dissociation inhibitor 2 (ARHGDIB) was detected in recipients with c-aABMR as compared to recipients with no rejection. However, ARHGDIB autoantibodies did not associate with graft survival. Levels of autoantibodies against angiotensin II type 1-receptor (AT1R) and peroxisomal trans‐2‐enoyl‐CoA reductase (PECR) were increased in recipients with interstitial fibrosis in their kidney biopsy. Only the signal for AT1R autoantibody showed a linear relationship with the degree of interstitial fibrosis and was associated with graft survival.

In conclusion, anti-ARHGDIB autoantibodies are increased when c-aABMR is diagnosed but are not associated with graft survival, while higher levels of AT1R autoantibody are specifically associated with the presence of interstitial fibrosis and graft survival.

非 HLA 自身抗体在肾移植的慢性活性抗体介导的排斥 (c-aABMR) 中的作用在很大程度上是未知的。在这项研究中，使用最近开发的基于 Luminex 的多重检测方法研究了非 HLA 自身抗体的存在和临床相关性。移植后至少 6 个月接受同种异体肾活检并诊断为 c-aABMR（n = 36）或无排斥（n = 21）的患者被包括在内。检测移植前血清和活检时血清中 14 种相关自身抗体的存在。

与没有排斥反应的受者相比，在接受 c-aABMR 的受者中检测到针对 Rho GDP 解离抑制剂 2 (ARHGDIB) 的自身抗体的明显更高的信号。然而，ARHGDIB 自身抗体与移植物存活无关。在肾活检中出现间质纤维化的受者中，针对血管紧张素 II 1 型受体 (AT1R) 和过氧化物酶体转 2-烯酰辅酶 A 还原酶 (PECR) 的自身抗体水平升高。只有 AT1R 自身抗体的信号与间质纤维化程度呈线性关系，并与移植物存活相关。

总之，当诊断出 c-aABMR 时，抗 ARHGDIB 自身抗体会增加，但与移植物存活无关，而较高水平的 AT1R 自身抗体与间质纤维化和移植物存活的存在特异性相关。