Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
BMC Nephrol. 2012 Jun 1;13:32. doi: 10.1186/1471-2369-13-32.
Antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis (CGN) is a major cause of rapidly progressive glomerulonephritis (RPGN). ANCA-associated CGN is generally classified into pauci-immune RPGN, in which there are few or no immune complexes.
A 78-year-old man presented with RPGN after a 7-year course of chronic proteinuria and hematuria with stable renal function. A blood examination showed a high titer of myeloperoxidase (MPO)-ANCA. A renal biopsy showed crescentic glomerulonephritis with abundant subepithelial, intramenbranous and subendothelial deposits by electron microscopy, leading to the diagnosis of ANCA-associated CGN superimposed on type 3 membranoproliferative glomerulonephritis (MPGN).
This case is unique in that type 3 MPGN and MPO-ANCA-associated CGN coexisted, and no similar case has been reported to date. Because ANCA-associated CGN has a predilection for elderly individuals and primary type 3 MPGN is rarely seen in this age group, coincidental existence appears less likely. This case may confer valuable information regarding the link between immune complex and ANCA-associated CGN.
抗中性粒细胞胞质抗体（ANCA）相关性新月体肾小球肾炎（CGN）是急进性肾小球肾炎（RPGN）的主要病因。ANCA 相关性 CGN 通常分为寡免疫 RPGN，其中免疫复合物较少或没有。
一名 78 岁男性，7 年来慢性蛋白尿和血尿，肾功能稳定，后出现 RPGN。血液检查显示髓过氧化物酶（MPO）-ANCA 滴度高。肾活检显示新月体肾小球肾炎，电镜下可见大量上皮下、内皮下和内膜下沉积物，诊断为 ANCA 相关性 CGN 合并 3 型膜增生性肾小球肾炎（MPGN）。
该病例的独特之处在于 3 型 MPGN 和 MPO-ANCA 相关性 CGN 同时存在，迄今为止尚未报道类似病例。由于 ANCA 相关性 CGN 偏爱老年人群，而该年龄段原发性 3 型 MPGN 很少见，因此不太可能巧合存在。该病例可能为免疫复合物与 ANCA 相关性 CGN 之间的联系提供有价值的信息。
