糖尿病肾病患者尿足细胞脱落及其与尿蛋白的关系

目的 通过观察糖尿病肾病(DN)患者尿中足细胞及肾活检标本足细胞脱落情况,探讨尿中足细胞脱落与尿蛋白、空腹血糖、肌酐的关系.方法 选取2005年1月至2006年12月间天津医科大学总医院收治的DN患者50例,微小病变(MCD)患者25例及正常人对照组10例,按照慢性肾脏病(CKD)分期将DN患者分为5组,其中CKD I期15例,CKD Ⅱ期10例,CKD Ⅲ期8例,CKD IV期9例,CKD V期8例;另按尿蛋白量将DN患者分为3组,其中少量蛋白尿组(<1.0 g/d)13例,中量蛋白尿组(1-3.5 g/d)20例,大量蛋白尿组(>3.5 g/d)17例,采用间接免疫荧光法检测尿足细胞数目及肾小球足细胞特异性蛋白(podocalyxin,PCX)表达;分别统计各组中尿足细胞数目;同时检测各组患者24h尿蛋白、肌酐、空腹血糖,多组计量指标比较采用单因素方差分析,双变量分析采用Pearson相关分析.结果 DN组尿中足细胞的阳性率为88%(44/50);微小病变(MCD)组及正常对照组中阳性率为0;DN组患者的肾活检标本中,肾小球足细胞PCX表达缺失,MCD组肾活检标本足细胞PCX呈完整连续性表达.少量蛋白尿组尿足细胞数目(1.5±1.0)个/ml,中等量蛋白尿组(2.2±0.7)个/ml及大量蛋白尿组(3.5±1.3)个/ml,除少量蛋白尿与中量蛋白尿组差别不具有统计学意义外,其他组间差别均具有统计学意义(P<0.05).DN患者尿足细胞数目与蛋白尿(r=0.785,P<0.05)、I-Ⅲ期患者同期SCr呈正相关(r=0.466,P<0.05);而与FBG无相关性(P>0.05).结论 DN进展过程中存在足细胞损伤.DN足细胞脱落与尿蛋白、CKD I至Ⅲ期同期SCr呈正相关,与Ⅳ至V期SCr、FBG无关.

Correlation between podocyte excretion and proteinuria in patients with diabetic nephropathy

Objective To indicate the mechanism of podocyte injury in diabetic nephropathy(DN)patients by identifying the urinary podocytes and observe the situation of detached podocytes in glomeruli;to discuss the correlation between the urinary podocyte excretion and the proteinuria,blood glucose(FBG),serum creatinine(SCr)in DN patients by detection of theses items in different phases.Methods The DN patients were divided into five groups according to the CKD phases, and were divided into three groups according to the volume of proteinuria,namely small,medium and large-volume-proteinuria group.Urinary podocytes and the podocalyxin(PCX)expression state of podocytes in glomeruli were identified and observed by indirect immunofluorescent method. The urinary podocytes of every group were caculated respectively.Then the podocyte number were calculated respectively.Meanwhile,the 24 h proteinuria,FBG and the SCr of DN pateints were tested.The correlation among the proteinuria,SCr,FBG and the urinary podocyte number of DN pateints was analyzed statistcally.Results Urinary podocytes were found in 88 percent of patients with DN,whereas O of patients with MCD and healthy cases.The absence of expression of PCX was found in DN patients.In contrast,PCX wag expressed integrally in MCD patients.The podocytes in smallvolume-proteinuria group was(1.5±1.0)/ml,medium-volume-proteinuria group(2.2±0.7)/ml and large-volume-proteinuria group(3.5±1.3)/ml,respectively.The difference from small and medium groups were not signifficent statistically,the others were all significant.The podocyte number increased according to the proteinuria.The correlation between urinary podocyte number and proteinuria,SCr of CKD I to Ⅲ DN patients and urinary podocytes number were positive statistically.However,the correlation between SCr of CKD IV to V patients and urinary podocyte number, FBG and urinary podocyte number were not significant statistically.Condusiom the mechanism of the podocyte injury in DN patients is present.The podocyte injury in DN may positively correlate to the proteinuria and SCr of CKD I to Ⅲ patients,but the FBG and SCr of CKDIV-V patients may not correlate to the urinary podocyte number.