中文摘要：

目的对IgA肾病（IgAN）患者的临床及病理资料进行分析，旨在探讨补体活化在IgAN中的意义，为临床治疗提供依据。方法回顾性分析本院确诊的原发性IgAN患者，记录患者基线一般情况、临床指标、病理学检查及随访结果。根据免疫荧光下补体C3在系膜区沉积情况，分为阴性、弱阳性、强阳性3组，血c3降低组的定义为血清C3〈85mg／dl。结果本研究纳人528例患者，平均随访3年。肾组织C3沉积阴性组、弱阳性组、强阳性组患者分别为119例（22．5％）、164例（31．1％）和245例（46．4％）；血c3降低组患者93例（21．7％），血C3正常组335例（78-3％）；系膜区c3沉积与血清c3水平呈负相关（r=-0．209，P〈0．01）；不同肾组织C3沉积组间年龄、性别差异无统计学意义；随。肾组织C3沉积加重，患者基线血肌酐、尿酸、血IgA水平升高，估算肾小球滤过率（eGFR）、体质量指数（BMI）降低（P〈0．05），C3沉积较多的患者肾组织毛细血管内细胞增生和肾小管萎缩、。肾间质纤维化更为严重（P〈0．05）。与血c3正常组比较，血c3降低组患者白细胞、血红蛋白、三酰甘油、胆固醇、eGFR水平较低，而血肌酐水平较高（P〈0．05）。随访期间，共有54例患者进入终末期肾病（ESRD），血c3降低组ESRD发生率为23．7％，正常组为8．4％，Kaplan．Meier分析显示血C3降低组。肾脏中位生存时间显著低于c3正常组[（145．0±22．5）个月比（150．8±17．0）个月，P〈0．011。Cox回归分析显示，校正性别、年龄和临床指标（平均动脉压、eGFR、白蛋白、尿蛋白、血红蛋白水平）后，血清C3降低（HR=0．97，95％C10．96，0．99，P〈0．01）为患者进入ESRD的独立危险因素。结论IgAN患者存在不同程度补体系统活化，补体活化与患者基础肾功能及临床预后相关，血清C3下降为患者进入ESRD的独立危险因素，提

英文摘要：

Objective To explore the clinical significance of complement activation in IgA nephropathy （IgAN） patients and provide new potential therapy targets. Methods Biopsy- proven IgAN patients admitted in our renal center were retrospectively recruited. Demographic, baseline clinical and pathological data were recorded as well as the follow-up results. Patients were divided into three groups, negative, weak positive and strong positive group, according to the intensity of C3 deposition in mesangial area of glomurili. Decreased serum C3 level was defined as C3 〈 85 mg/dl. Results In this study, 528 IgAN patients were recruited and mean follow-up time was 3 years. There were 119 （22.5%）, 164（31.1%）, 245（46.4%） patients in the negative, weak positive and strong positive group respectively; 93（21.7%） patients had decreased serum C3 level and 335（78.3%） patients had normal serum C3 level; Significant negative correlation was found between mesangial area of C3 deposition and serum level of C3（r =-0.209, P 〈 0.01）. The age or sex were similar among different groups of mesangial C3 deposition. In univariate analysis, higher baseline serum creatinine, uric acid and IgA levels, and lower estimated glomerular filtration rate（eGFR）, body mass index （BMI） levels were associated with a higher grade of mesangial C3 deposition （P 〈 0.05）. Endocapillary hypercellularity and tubular atrophy or interstitial fibrosis were more prominent in patients with higher grade mesangial deposition of C3. Compared with the patients with normal serum C3 level, patients with decreased serum C3 level had lower white blood cells, hemoglobin, triglyceride, cholesterol, eGFR level and higher serum creatinine level （P 〈 0.05）. During the follow- up, a total of 54 patients developed to end stage renal disease （ESRD）, the incidence of ESRD was 23.7% in patients with decreased serum C3 level and 8.4% with normal C3 level. Kaplan- Meier analysis showed that median outcome-free survival time of patients wit