影响IgA肾病预后的危险因素分析

目的通过分析IgA肾病患者的临床资料及病理特征,探讨影响IgA肾病患者长期肾存活率的危险因素。方法分析724例肾活检确诊为IgA肾病患者肾活检时的临床资料及病理特征。对所有患者进行随访,每3~6个月检测尿蛋白、血肌酐(Scr)等指标,以Scr值比基础值升高1倍以上为观察终点。随访时间>6个月者才纳入成功随访病例。用非参数乘积限估计法(Kaplan-Meier法)分析生存率,用Cox回归模型分析影响预后的危险因素。结果共有317例IgA肾病患者成功随访,肾活检后平均随访时间为(43·5±32·2)个月。有39例(12·3%)患者进入随访终点,其1、3、5、10年肾存活率分别为99·5%、93·1%、84·5%和60·1%。Cox比例风险模型单因素分析发现病程长、肾活检时血Scr>115μmol/L、尿蛋白>1·0g/24h、高血压、Lee氏分级Ⅳ级或Ⅳ级以上、中重度肾小球硬化、新月体形成、中重度肾间质纤维化和肾小血管损害是影响IgA肾病预后的危险因素;多因素分析结果显示,蛋白尿、血Scr水平、肾小球硬化、新月体形成、肾间质纤维化是影响IgA肾病预后的独立危险因素。结论蛋白尿、肾功能不全、肾小球硬化、新月体形成和肾间质纤维化是影响IgA肾病预后的独立危险因素。

Risk factors affecting the long-term outcome of IgA nephropathy

OBJECTIVE: To study the risk factors predicting long-term renal survival of IgA nephropathy in Chinese. METHODS: Clinical and pathological data of 317 patients (124 males and 193 females) with IgA nephropathy confirmed by renal biopsy in our center from January 1987 to February 2003 were reviewed retrospectively and were correlated with outcomes. A semiquantitative scoring system was used to evaluate individual pathological lesion of the kidney. Patients were followed for at least 6 months and doubling of serum creatinine level was defined as endpoint of follow-up. Renal survival was calculated by Kaplan-Meier survival analysis and risk factors of progression were analyzed by using univariate and multi-variate Cox regression models. RESULTS: The average age at renal biopsy was (30.1 +/- 10.9) years and the average duration from onset of disease to the time of biopsy was (20.1 +/- 33.7) months. Thirty-two percent of the patients had 24 h-urinary protein excretion greater than 1.0 g at the time of biopsy. Thirty-two percent of the patients had hypertension and 20.8% had renal insufficiency. Thirty-five percent of the patients were of Lee's grade IV or above and 20.5% presented with small proportion of crescent formation (usually less than 20%). Patients were followed for an average duration of (43.5 +/- 32.2) months with 39 patients (12.3%) reaching the endpoint. The 1-, 3-, 5- and 10-year renal survival was 99.5%, 93.1%, 84.5% and 60.1% respectively. Univariate Cox regression analysis revealed that longer duration of the disease before biopsy, serum creatinine > 115 micromol/L, proteinuria > 1.0 g/d, hypertension, Lee's grading of IV-V, moderate-severe glomerulosclerosis, crescent formation, moderate-severe interstitial fibrosis and renal arteriolar lesion were risk factors of disease progression, with an odds ratio of 1.007, 9.61, 7.31, 3.97, 5.41, 5.78, 4.65, 14.05 and 2.28 respectively (P < 0.001). Episodic macro-hematuria had an odds ratio of 0.194 (P < 0.05). Age, sex, serum cholesterol and triglyceride level had no significant impact on prognosis. Proteinuria, elevated serum creatinine, glomerulosclerosis, crescent formation and interstitial fibrosis were confirmed to be independent risk factors by multi-variate Cox regression model while the remaining variables were not statistically significant. Patients with both renal insufficiency and proteinuria greater that 1.0 g/24 h at the time of biopsy had a very poor 5-year renal survival (41.8%). CONCLUSIONS: Proteinuria, renal insufficiency, glomerulosclerosis, crescent formation and interstitial fibrosis were independent risk factors predicting the renal survival. IgA nephropathy presented with proteinuria, hypertension and crescent formation may need intervention.