Miura Kenichiro, Shirai Yoko, Kaneko Naoto, Yabuuchi Tomoo, Ishizuka Kiyonobu, Horita Shigeru, Furusawa Miyuki, Unagami Kohei, Okumi Masayoshi, Ishida Hideki, Tanabe Kazunari, Koike Junki, Honda Kazuho, Yamaguchi Yutaka, Hattori Motoshi
Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo, Japan.
Department of Pathology, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
Nephron. 2020;144 Suppl 1:97-101. doi: 10.1159/000511322. Epub 2020 Nov 25.
Glomerular IgG deposition is rarely observed in antibody-mediated rejection. Here, we report chronic active antibody-mediated rejection with linear IgG deposition on glomerular capillary walls in a pediatric kidney transplant recipient. A 6-year-old boy with bilateral renal hypoplasia underwent preemptive deceased-donor kidney transplantation. Five years after the transplantation, an allograft biopsy revealed chronic active antibody-mediated rejection with diffuse linear IgG deposition on glomerular capillaries. Anti-glomerular basement membrane antibody, donor-specific anti-human leukocyte antigen (HLA) antibodies, and anti-angiotensin II type 1 receptor antibody were negative. A multiplex antibody assay identified anti-major histocompatibility complex class I chain-related molecule A antibody. Additionally, a single-antigen bead assay identified autoantibodies to 12 non-HLA antigens, including vimentin and glutathione S-transferase theta-1. To investigate whether IgG autoantibodies in the patient's serum bind to antigens on glomerular capillaries, we incubated the patient's serum with 0-h biopsy specimens of tissue donated to the patient and a control subject, both obtained immediately after nephrectomy from respective donors. IgG signals were observed in neither patient nor control samples. Nevertheless, linear IgG deposition may be explained by the binding of autoantibodies to non-HLA antigens that are usually hidden and only exposed via severe endothelial cell injury. Further studies are needed to confirm the significance of non-HLA antibodies in glomerular IgG deposition.
在抗体介导的排斥反应中很少观察到肾小球IgG沉积。在此，我们报告了一名小儿肾移植受者发生的慢性活动性抗体介导的排斥反应，其肾小球毛细血管壁上有线性IgG沉积。一名患有双侧肾发育不全的6岁男孩接受了尸体供肾的抢先肾移植。移植后5年，移植肾活检显示为慢性活动性抗体介导的排斥反应，肾小球毛细血管上有弥漫性线性IgG沉积。抗肾小球基底膜抗体、供者特异性抗人白细胞抗原（HLA）抗体和抗血管紧张素II 1型受体抗体均为阴性。多重抗体检测鉴定出抗主要组织相容性复合体I类链相关分子A抗体。此外，单抗原珠试验鉴定出针对包括波形蛋白和谷胱甘肽S-转移酶θ-1在内的12种非HLA抗原的自身抗体。为了研究患者血清中的IgG自身抗体是否与肾小球毛细血管上的抗原结合，我们将患者血清与分别从各自供者肾切除术后立即获得的供该患者和一名对照受试者的组织0小时活检标本进行孵育。在患者和对照样本中均未观察到IgG信号。然而，线性IgG沉积可能是由于自身抗体与通常隐藏且仅在严重内皮细胞损伤时才暴露的非HLA抗原结合所致。需要进一步研究以证实非HLA抗体在肾小球IgG沉积中的意义。
