Department of Nephrology and Blood Purification, Kidney Disease Center, Tokyo Medical University Hachioji Medical Center, 1163 Tatemachi, Hachioji, Tokyo, 193-0998, Japan.
BMC Nephrol. 2019 Jan 25;20(1):25. doi: 10.1186/s12882-019-1207-3.
Anti-glomerular basement membrane (GBM) glomerulonephritis does not usually coexist with another glomerulonephritis such as IgA nephropathy. We present a rare case having a combination of these two diseases, and furthermore, histological evaluation could be performed before and after the development of anti-GBM glomerulonephritis over a period of only10 months.
A 66-year-old woman was admitted with complaints of microscopic hematuria and mild proteinuria for the past 3 years. Serum creatinine level was normal at that time. The first renal biopsy was performed. Light microscopy revealed mesangial proliferative glomerulonephritis with fibro-cellular crescents in one out of 18 glomeruli, excluding one global sclerotic glomerulus. Immunofluorescence (IF) showed IgA and C3 deposition in the mesangium. Therefore, the diagnosis was IgA nephropathy. Eight months later, the patient's serum creatinine suddenly rose to 4.53 mg/dL and urinalysis showed 100 red blood cells per high power field with nephrotic range proteinuria (12.3 g/g). The serological tests revealed the presence of anti-GBM antibody at the titer of 116 IU/mL. Treatments were begun after admission, consisting of hemodialysis, plasma exchange, and intravenous methylprednisolone pulse therapy. At 4 weeks after admission, the second renal biopsy was performed. Light microscopy revealed crescents in 18 of 25 glomeruli, excluding six global sclerotic glomeruli. IF showed linear IgG deposition along the GBM in addition to granular IgA and C3 deposition. Based on these findings, the diagnosis of anti-GBM glomerulonephritis and IgA nephropathy was confirmed. Renal function was not restored despite treatment, but alveolar hemorrhage was prevented.
We report a patient with a diagnosis of anti-GBM disease during the course of IgA nephropathy. This case strongly suggests that the presence of autoantibodies should be checked to rule out overlapping autoimmune conditions even in patient who have previously been diagnosed with chronic glomerulonephritis, such as IgA nephropathy, who present an unusually rapid clinical course.
抗肾小球基底膜 (GBM) 肾小球肾炎通常不会与其他肾小球肾炎如 IgA 肾病共存。我们报告了一例罕见的同时存在这两种疾病的病例，此外，在仅 10 个月的时间内，在抗 GBM 肾小球肾炎发展之前和之后，可以进行组织学评估。
一名 66 岁女性因过去 3 年来出现镜下血尿和轻度蛋白尿而入院。当时血清肌酐水平正常。进行了第一次肾活检。光镜下可见 18 个肾小球中有 1 个肾小球出现局灶节段性肾小球系膜细胞增生伴纤维细胞性新月体，1 个肾小球为全球硬化。免疫荧光 (IF) 显示系膜区 IgA 和 C3 沉积。因此，诊断为 IgA 肾病。8 个月后，患者的血清肌酐突然升高至 4.53mg/dL，尿分析显示每高倍镜视野有 100 个红细胞，伴有肾病范围蛋白尿（12.3g/g）。血清学检查显示抗 GBM 抗体滴度为 116IU/mL。入院后开始治疗，包括血液透析、血浆置换和静脉注射甲基强的松龙脉冲治疗。入院后 4 周，进行了第二次肾活检。光镜下可见 25 个肾小球中有 18 个出现新月体，6 个肾小球为全球硬化。IF 显示除了颗粒状 IgA 和 C3 沉积外，还有 IgG 沿 GBM 线性沉积。根据这些发现，诊断为抗 GBM 肾小球肾炎和 IgA 肾病。尽管进行了治疗，但肾功能仍未恢复，但预防了肺泡出血。
我们报告了一例在 IgA 肾病过程中诊断为抗 GBM 疾病的患者。该病例强烈提示，即使患者以前被诊断为慢性肾小球肾炎，如 IgA 肾病，出现异常快速的临床病程，也应检查自身抗体以排除重叠自身免疫性疾病。
