The reclassification of membranoproliferative glomerulonephritis (MPGN) into immune-complex MPGN (IC-MPGN) and C3 glomerulopathy (C3G) based on immunofluorescence findings in kidney biopsies has provided insights into these two distinct diseases. C3G is further classified into dense deposit disease and C3 glomerulonephritis (C3GN) based on electron micrographic findings. Although these diseases have poor outcomes, limited Japanese literature confined to small, single-center cohorts exist on these diseases. We retrospectively analyzed 81 patients with MPGN type I and III from 15 hospitals in the Japan Renal Biopsy Registry to compare demographic, clinical characteristics and treatment outcomes of patients with IC-MPGN to those with C3GN. Of the 81 patients reviewed by immunofluorescence findings in kidney biopsies, 67 patients had IC-MPGN and 14 patients had C3GN. Age at diagnosis and systolic and diastolic pressure were higher and proteinuria and impaired renal function were significantly more prevalent in patients with IC-MPGN than those with C3GN. About 80% of the patients in both groups were treated with immunosuppressive therapy. At last follow-up (median 4.8 years), complete remission rate of proteinuria was significantly higher in patients with C3GN (64.3%) than in those with IC-MPGN (29.9%; P = 0.015). The renal survival rate was lower in patients with IC-MPGN when compared to C3GN (73.1% vs. 100%; log-rank, P = 0.031). Systolic blood pressure and renal function at baseline were independent predictors of progression to end-stage kidney disease. The overall prognosis of patients with C3GN is more favorable than for patients with IC-MPGN.

中文翻译：

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日本免疫复合物膜增生性肾小球肾炎和 C3 肾小球肾炎的人口统计学、临床特征和治疗结果：对日本肾脏活检注册数据的回顾性分析。

根据肾活检中的免疫荧光结果，将膜增生性肾小球肾炎 (MPGN) 重新分类为免疫复合物 MPGN (IC-MPGN) 和 C3 肾小球病 (C3G)，为这两种不同的疾病提供了见解。C3G 根据电子显微镜检查结果进一步分为致密沉积病和 C3 肾小球肾炎 (C3GN)。尽管这些疾病的预后很差，但关于这些疾病的日本文献仅限于小型单中心队列。我们回顾性分析了来自日本肾脏活检注册中心 15 家医院的 81 名 MPGN I 型和 III 型患者，以比较 IC-MPGN 患者与 C3GN 患者的人口统计学、临床特征和治疗结果。在肾活检免疫荧光结果审查的 81 名患者中，67 名患者患有 IC-MPGN，14 名患者患有 C3GN。与 C3GN 患者相比，IC-MPGN 患者的诊断年龄、收缩压和舒张压更高，蛋白尿和肾功能受损的发生率明显更高。两组中约80%的患者接受了免疫抑制治疗。在最后一次随访时（中位 4.8 年），C3GN 患者的蛋白尿完全缓解率（64.3%）显着高于 IC-MPGN 患者（29.9%；P = 0.015）。与 C3GN 相比，IC-MPGN 患者的肾脏存活率较低（73.1% 对 100%；对数秩，P = 0.031）。基线时的收缩压和肾功能是进展为终末期肾病的独立预测因子。C3GN 患者的总体预后优于 IC-MPGN 患者。