Department of Nephrology, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.
Department of Nephrology and Hypertension, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan.
CEN Case Rep. 2020 Nov;9(4):318-325. doi: 10.1007/s13730-020-00478-6. Epub 2020 Apr 27.
We report here two cases of membranoproliferative glomerulonephritis that developed during treatment of rheumatoid arthritis with tocilizumab. In both cases, the initial findings were proteinuria and haematuria, followed by development of bilateral lower leg oedema. One of the patients was weakly positive for anti-nuclear antibody; both had hypocomplementaemia. The patients' renal impairment gradually resolved with discontinuation of tocilizumab followed by treatment with moderate doses of oral prednisolone. Pathological examination of renal biopsies resulted in diagnoses of immunocomplex glomerulonephritis and immunofluorescence staining revealed depositions of IgG, IgA, and IgM, accompanied by C3. Tocilizumab rarely induces autoimmune disorders; therefore, the underlying mechanism is unknown. One patient with immunocomplex glomerulonephritis that may have been associated with tocilizumab therapy for rheumatoid arthritis has been reported previously; that patient and our two are similar in their clinical courses and pathological findings. We conclude that such glomerulonephritis can occur during tocilizumab treatment, but this is rare. Clinicians should be aware of the possibility of paradoxical development of autoimmune diseases during tocilizumab therapy.
我们在此报告两例在使用托珠单抗治疗类风湿关节炎期间发生的膜增生性肾小球肾炎。在这两种情况下，最初的发现都是蛋白尿和血尿，随后出现双侧小腿水肿。其中一位患者抗核抗体弱阳性；两者均有低补体血症。随着托珠单抗的停用和中等剂量口服泼尼松龙的治疗，患者的肾损伤逐渐得到缓解。肾活检的病理检查结果诊断为免疫复合物性肾小球肾炎，免疫荧光染色显示 IgG、IgA 和 IgM 沉积，伴有 C3。托珠单抗很少引起自身免疫性疾病；因此，其潜在机制尚不清楚。先前曾有报道称，一例免疫复合物性肾小球肾炎可能与类风湿关节炎的托珠单抗治疗有关；该患者和我们的两例在其临床过程和病理发现上相似。我们得出结论，此类肾小球肾炎可能在托珠单抗治疗期间发生，但这种情况很少见。临床医生应该意识到在托珠单抗治疗期间发生自身免疫性疾病的可能性。
