C3肾小球肾炎的临床表现及病理特征

目的:分析17例C3肾小球肾炎的临床表现、病理特征和治疗反应,旨在提高对此病的认识。方法:回顾性分析17例确诊为C3肾小球肾炎患者的临床、病理资料及疗效。结果:(1)一般情况:男11例,女6例,平均年龄(31.5±19.4)岁(9～72岁),肾活检时病程1周～8年。14例患者起病前无明确诱因,13例(76.5%)以水肿、尿检异常为首发症状,3例伴肾外症状;(2)临床表现及实验室检查:肾病综合征5例,尿检异常8例,急进性肾炎3例,反复发作肉眼血尿1例;镜下血尿11例、肉眼血尿4例、高血压10例、肾功能减退4例;平均尿蛋白定量(3.1±3.2)g/d,6例蛋白尿>3.5g/24h,血清白蛋白(33.8±6.1)g/L,低补体C3血症11例,贫血7例;5例患者检测C3肾炎因子、补体H因子及抗H因子抗体,其中1例C3肾炎因子阳性;(3)病理特点:17例患者免疫荧光染色均见补体C3呈颗粒状弥漫分布于肾小球毛细血管外周袢;12例组织学符合膜增生样病变,5例以系膜增生病变为特征;超微结构见肾小球毛细血管袢内皮下、系膜区电子致密物沉积,8例伴少量上皮侧电子致密物沉积;(4)随访:除1例失访外,16例患者大多接受免疫抑制剂治疗,随访4月～5年,其中1例完全缓解,6例部分缓解,7例病情无变化,2例进入慢性肾功能衰竭。结论:C3肾小球肾炎是新近被认可的疾病,其临床表现缺乏特征性,免疫荧光染色以C3沉积为主,超微结构见肾小球毛细血管袢内皮下和(或)系膜区电子致密物沉积。该病目前尚无有效的治疗方法,其发病机制尚需深入研究。

C3 glomerulonephritis:clinicopathologic analysis of 17 cases

Objective:To investigate the clinical and pathological features of complement C3(C3) glomerulonephritis.Methodology:Seventeen Chinese patients diagnosed with C3 glomerulonephritis by clinical and histopathological methods(light microscopy,immunofluorescence and electron microscopy) were enrolled.The clinical data and pathologic features were analyzed.Results:There were 11 males and 6 females with average age of(31.5±19.4) years(9～72) and renal involvement of(30.0±27.8) months(from one week to 8 years).Forteen patients had no obvious predisposing causes.The initial symptoms were edema and proteinuria in majority of patients(76.5%).Among them,5 had nephritic syndrome,and 3 presented rapidly progressive glomerulonephritis.Urinary analysis showed proteinuria of(3.1±3.2)g/d with micro-hematuria(64.7%),4 had gross hematuria.Hypertension was in 10 cases,anemia in 7 cases and elevated level of serum creatinine in 4 cases.11 patients showed the low serum level of complement C3.C3 nephritic factor(C3NeF) were carried out in 5 cases,only one patient was positive.Renal biopsy revealed membrane proliferative glomerulonephritis(MPGN) in 12 patients(70.6%)with endothelial and mesangial proliferative.Granular C3 were deposited along with GBM,but absence of substantial immunoglobulin by immunofluorescence(IF).Electron microscopy observation showed the presence of subendothelial and mesangial electron-dense deposits.Sixteen patients followed-up for 4 months to 5 years,one was complete remission,6 cases were partial remission,and 7 cases had no response to immunosuppressive therapy Conclusion:C3 glomerulonephritis,newly recognized in recent years,was no significant clinical features.Immunofluorescence evidence showed C3 predominantly deposited within the GBM.Electron microscopy was valuable in the diagnosis.There was no effective treatment for C3 glomerulonephritis.Further investigation of mechanism is needed.