Iida Ayana, Wada Yukihiro, Hayashi Junichi, Tachibana Shohei, Inaba Taro, Iyoda Masayuki, Honda Kazuho, Shibata Takanori
Division of Nephrology, Department of Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8666, Japan.
Division of Microscopic Anatomy, Department of Anatomy, Showa University School of Medicine, Tokyo, Japan.
CEN Case Rep. 2019 Nov;8(4):233-238. doi: 10.1007/s13730-019-00399-z. Epub 2019 Apr 29.
Membranous nephropathy (MN) caused by disease-modifying antirheumatic drugs is relatively common in patients with rheumatoid arthritis (RA). However, MN rarely occurs due to RA itself. We describe a 61-year-old woman with RA who showed nephrotic syndrome. She was admitted because of systemic edema and severe arthritis. She had a long history of RA successfully treated with methotrexate (MTX), but discontinued all treatments 4 years before hospitalization. She had never been treated with bucillamine or gold. Laboratory test results were positive for anti-cyclic citrullinated peptide antibody and negative for anti-nuclear antibody. Renal pathologic findings were compatible with MN. Immunofluorescence microscopy showed IgG, IgA, κ, λ, and C3 along the glomerular capillary wall, whereas deposition of IgM or C1q was not detected. In terms of the IgG subclasses, only IgG2 findings were positive. Results for glomerular antigen and serum antibody for M-type phospholipase A2 receptor and thrombospondin type 1 domain-containing 7A were negative. HLA type did not include the HLA-DQA1 gene that is a concern in primary MN (PMN). She responded to intensive immunosuppressive therapy consisting of prednisolone, tacrolimus, and MTX with a parallel reduction of proteinuria. Based on assessments for differentiating PMN from secondary MN (SMN), the diagnosis of the present case was incompatible with PMN. Taken together, we consider that SMN in the present case was due to RA itself rather than drug-induced MN.
抗风湿药物引起的膜性肾病（MN）在类风湿关节炎（RA）患者中相对常见。然而，MN很少由RA本身引起。我们描述了一名61岁患有RA且表现为肾病综合征的女性。她因全身性水肿和严重关节炎入院。她有长期的RA病史，曾成功接受甲氨蝶呤（MTX）治疗，但在住院前4年停止了所有治疗。她从未接受过青霉胺或金制剂治疗。实验室检查结果抗环瓜氨酸肽抗体呈阳性，抗核抗体呈阴性。肾脏病理结果与MN相符。免疫荧光显微镜检查显示IgG、IgA、κ、λ和C3沿肾小球毛细血管壁沉积，而未检测到IgM或C1q沉积。就IgG亚类而言，仅IgG2结果呈阳性。M型磷脂酶A2受体和含血小板反应蛋白1型结构域7A的肾小球抗原和血清抗体结果均为阴性。HLA类型不包括原发性MN（PMN）中所关注的HLA - DQA1基因。她对由泼尼松龙、他克莫司和MTX组成的强化免疫抑制治疗有反应，蛋白尿同时减少。基于区分PMN与继发性MN（SMN）的评估，本病例的诊断与PMN不相符。综上所述，我们认为本病例中的SMN是由RA本身引起，而非药物性MN。
