中文摘要：

目的：分析C3肾病（C3G）及其亚型致密物沉积病（DDD）和C3肾小球肾炎（C3GN）的临床、病理及预后特征,以提高对此病的认识. 方法：回顾性分析54例确诊为C3G患者的临床表型、病理资料及预后,并比较DDD和C3GN的区别. 结果：C3G患者平均发病年龄（31.7±16.1）岁,44.4％以肾病综合征起病,22.2％肾功能异常,81.5％出现低补体血症,61％抗链球菌溶血素“0”阳性.C3G病理上以膜增生样病变（61.1％）和系膜增生性病变（27.8％）为主,补体C3主要沉积于肾小球毛细血管袢（98.1％）和系膜区（63％）,另59.3％伴免疫球蛋白沉积.与C3GN相比,DDD患者发病年龄轻（P＜0.05）,低蛋白血症更显著（P＜0.05）,伴发高血压的比例低（P＜0.05）,循环补体水平无差异.病理上,DDD患者的膜增生及新月体病变较G3GN更为常见;除血管袢和系膜区的C3沉积外,DDD常伴肾小管基膜及间质血管区的沉积（P＜0.001）.电镜观察DDD患者电子致密物主要沉积于基膜内、肾小管基膜和包囊壁,C3GN组主要位于系膜区、内皮下和上皮侧（P＜0.001）.两组随访5年的累积肾生存率无差异. 结论：这是目前亚洲人群最大样本C3G的报道,C3G以血清补体C3减低,免疫荧光C3沉积为主,超微结构电子致密物沉积与C3沉积为特征.DDD和C3GN主要在C3和电子致密物沉积部位上有差异.

英文摘要：

Objective： To investigate the clinicopathologic features and the prognosis in patients with C3 glomerulopathy （C3G）. Methodology：Fifty four cases with C3G were enrolled into this retrospective study. They were divided into two subtypes： C3 glomerulonephritis （C3GN, n= 39） and dense deposit disease （DDD, n= 15）. Their clinicopathologic data and prognosis were investigated and compared. Results：They were 32 males and 22 females with an average age of 31.7± 16. 1 years old. They presented nephrotic syndrome in 44.4%, the low level of serum complement C3 in 81.5% and a higher titer of antistreptolysin-O （ASO） in 61%. They also showed multiple histologic patterns of glomerulopathy, such as membrane proliferative glomerulonephritis in 61.1% and mesangial proliferative in 27. 8%. fmmunohistology examinations showed that bright staining for C3 was evident within capillary wall in 98. 1% patients and in the mesangium in 63% patients. 32 （59. 3% ） cases were accompanied by the deposition of immunoglobulin. Compared with C3GN, those with DDD were younger （P = 0. 011 ）, the similar level of surem complement C3, lower level of serum albumin and fewer accompanied by hypertension （P= 0. 031 ）. More patients with DDD showed membrane proliferative and crescentic glomerulonephritis and presented C3 deposition within renal tubular basement membrance and interstitial vascular wall （P〈0. 001 ）, besides mesangium and capillary wall. Electron microscopy identified hyperosmiophilic dense deposits mainly occupying the lamina densa of the glomerular basement membrane, tubular basement membrane and Bowman＇s capsule in DDD group, while intramembranous, mesangial, subepithelial and subendothelial deposits were found in C3GN. There was no difference in the cumulative incidence of poor renal outcome between two groups. Conclusion：We have described the histopathologic findings among the largest cohort of patients with C3G in Asian. Patients with C3G presented surem complement C3 below normal, mainl