C3肾小球病病理特点及诊断

Pathological features and diagnosis of C3 glomerulopathy

C3肾小球病(C3 glomerulopathy)与补体旁路途径获得性和(或)先天性缺陷所致调节异常有关。是一类肾小球仅有C3沉积的疾病,无补体经典途径成分C4和C1q,无或极少量免疫球蛋白沉积。根据电子致密物沉积特点分为致密物沉积病(Dense deposit disease,DDD)和C3肾小球肾炎(C3 glomerulonephritis,C3GN)。光镜表现为膜增生性肾小球肾炎(MPGN)、毛细血管内增生性病变、系膜增生性病变和新月体肾炎。C3肾小球病诊断必须依赖肾活检,需对补体成分及基因学突变进行综合分析。

C3 glomerulopathy is resulting from abnormal control of the complement alternative pathway due to genetic and acquired complement abnormalities. Renal biopsy shows C3 in glomeruli on immunofluorescence, but there is no Clq or C4, and there is minimal or no immunoglobulin. On the basis of electron microscopy , C3 glomerulopathy is divided into dense deposit disease （DDD） and C3 glomerulonephritis （C3GN）. ＂Ihe morphology seen by light microscopy is variable and includes membranoprolfferative pattern, endocapillary proliferation, mesangialproliferation, and crescentic glomemlonephritis. ＂Ihe diagnosis of C3 glomerulopathy depends on renal biopsy. A biochemical evaluation of the AP, determination of autoantibodies, a comprehensive genetic screening, and testing for a plasma cell disorder should be considered.