轻度蛋白尿IgA肾病患者的临床和病理特征及预后分析

Clinico-pathological Characterization and Outcome of IgA Nephropathy with Mild Proteinuria

目的:探讨轻度蛋白尿(24 h蛋白尿<1 g/d)IgA肾病的临床、病理特征及预后分析。方法:回顾性分析2001年~2007年在本院肾活检确诊为原发性IgA肾病且蛋白尿<1 g/d,随访时间≥6个月,终点事件定义为肌酐较基础值翻倍或eGFR下降50%或进入ESRD,进一步将患者分为蛋白尿≤0.3 g/d和蛋白尿>0.3 g/d,比较两组间患者临床、病理特征及预后情况。采用Kaplan-Meier方法进行生存分析。结果:(1)共667例患者纳入研究,男393例(58.9%),女421例(63.1%),蛋白尿中位数为0.37 g/d(0.20~0.63 g/d),血清肌酐(Scr)中位数67.0(54.9~82.2μmol/L),平均肾小球滤过率(eGFR)(107.3±33.7)ml·min-1·1.73 m-2。两组比较临床指标中Scr、eGFR等组间差异存在统计学意义(P<0.05);(2)Lee分级以Ⅲ~Ⅴ型多见,占477例(71.5%),蛋白尿≤0.3 g/d组LeeⅢ~Ⅴ级占160例(58.4%),蛋白尿>0.3 g/d组占317例(80.7%)。蛋白尿>0.3 g/d患者,其LeeⅢ~Ⅴ级的风险较蛋白尿≤0.3 g/d组增加2.51倍;(3)中位随访时间90.3(68.6,114.4)月,共40例(6.0%)进入随访终点事件。Kaplan-Meier生存分析示组间生存率差异无统计学意义(Log Rank检验χ2=2.01,f=1,P=0.156)。结论:轻度蛋白尿IgA肾病患者肾功能及病理损伤并非一定轻微,在长期随访中部分患者可出现病情加重,甚至进展至肾功能减退。进一步降低蛋白尿是一种潜在的保护效应。

Objective：To explore the clinic - pathological features and outcomes of IgAN with mild proteinuria （ 〈 1 g/d）. Methods ：667 patients of IgAN with mild proteinuria in Hangzhou hospital of traditional Chinese medicine between 2001 and 2007 were retrospectively studied. The follow- up time was greater than 6 months, Endpoint events were defined as ≥ 50% loss of GFR from baseline,doubling of serum creatinineor entering ESRD. Patients were divided into twogroupsthrouth the weight of mild proteinu- ria. Group 1：proteinuria≤0.3 g/d; Group 2： proteinuria 〉0.3 g/d, Baseline and clinical characteristies of all IgAN patients were assessed and outcomes were reviewed. Multivariable associations between proteinuria and loss of renal function were examined by Cox proportional - hazards regression. Renal survival curves were generated with the Kaplan - Meier method. Results ： Of the 667 subjects （63.1% women, 58.9% man, mean age （ 33.4 ± 9.94） years）, median 24 hour proteinuria = 0.7 g/24 h （ IQR = 0. 3 - 1.4）, medi- an Serum creatinine = 67.0 （ IQR = 54.9 ± 82.2 μ mol/L）, mean GFR （ 107.3 ± 33.7 ml · min-1·1.73 m-2 ）. （ 1 ） There were difference in Scr,eGFR between two groups before renal biopsy （P 〈0.05） ; （2）Clinical indicators such as Scr,eGFR,Albetcshowed statistical difference in two groups （P 〈0.05）. Lee＇s classification as Ⅲ ~ Ⅴ as major, 477 cases as 71.5%. Lee＇s classification （Ⅲ ~ Ⅴ ） of group 1 were 160 cases（58.4% ）, while group 2 were 317 cases（ 80.7% ）. Group 2, the risk of serious pathological damage （Lee3 -5） increased 2.51 times compared with group 2; （3）Progression to renal failure was observed in 40（6.0% ） patients for a median of 90.3 （68.6,114.4）months. Univariate and multivariate Cox hazard regression model does not supported the value of mild proteinuria in predicting the prognosis of IgAN （P = 0. 160, P = 0. 072 ）. A Kaplan - Meier plot did not showed statistical differ- ence in two groups in survival rate （Log Rank χ2 = 2. 01, f= 1, P = 0. 156）. Conclusion：There was no correlation between the mild proteinuria and prognosis, while the loss of renal function and Pathological damage of IgAN with mild proteinuria may also be serious. In long -term follow -up, some patients may aggravate, or even progress to Loss of renal function. Further, reducing proteinuria is a potential protective method.