检测尿足细胞在活动性肾小球疾病中的意义

目的:探讨检测尿足细胞的方法可否作为无创评估肾小球损伤的指标.方法:采用抗人足细胞标记蛋白-Podocalyxin(PCX)抗体进行间接免疫荧光染色.60份尿标本采自我院肾内科住院患者,于肾活检前留取晨尿检测尿沉渣中足细胞,30份尿标本采自健康志愿者作为对照.60例患者均经皮肾活检,肾组织行光镜、免疫荧光和电镜检查作出病理诊断.根据肾小球病变活动性炎症损伤与慢性损伤分为两组,并与尿足细胞阳性和阴性发生率进行对比分析.结果:⑴间接免疫荧光尿沉渣染色抗足细胞PCX抗体仅与足细胞特异结合,可用于检测尿足细胞.⑵尿足细胞见于成人多种类型肾小球疾病,而健康成人尿足细胞阴性.⑶肾小球活动炎症性损伤者尿足细胞阳性率72%,慢性损伤者尿足细胞阳性率22.7%,两组比较差异有统计学意义(P<0.05).⑷尿足细胞阳性组肾小球病理平均活动指数积分154±60,尿足细胞阴性组肾小球病理平均活动指数积分82±46,两组比较差异有统计学意义(P<0.05).结论:小鼠抗人足细胞PCX单克隆抗体尿沉渣染色,是一种特异性检测尿足细胞的方法,这项无创检查可作为预测肾小球疾病活动的指标.

Significance of detecting urinary podocytes in patients with active glomerulonephritis

OBJECTIVE: To establish a reliable method for detecting urinary podocytes, as a non-traumatic marker to evaluate glomerular injury in patients with glomerulonephritis. METHODS: Sixty patients with renal diseases in our renal wards were diagnosed based on the pathological findings in their kidney biopsy tissues, which was examined by light microscopy, immunofluorescence and electron microscopy. Sediments of morning urinary samples were collected and centrifuged onto glass slides before kidney biopsy. Thirty healthy volunteers were enrolled as controls. The podocytes were identified by immunofluorescence staining by using monoclonal antibody against human podocalyxin (PCX) presenting on the surface of podocytes. The patients were divided into active inflammation group and chronic injury group according to their glomerular lesions. RESULTS: (1)The anti-human PCX antibody we used could specifically recognize the antigen expressed on podocytes in urine sediments examined by indirect immunofluorescence staining. (2) The PCX-positive staining cells in the urine were observed in various glomerulonephritis, and were absent in the healthy controls. (3) The rate of appearance of urinary podocytes was significantly higher in active inflammation group compared with that in chronic injury group (72% vs 22.7%, P<0.05). (4) The glomerular injury index in the patients with PCX-positive staining cells in the urine was markedly increased than that in the patients with PCX-negative staining cells (154+/-60 vs 82+/-46, P<0.05). CONCLUSION: The urinary podocytes could be detected in urine sediments from patients with glomerulonephritis by using anti-human PCX antibody, and this method may find further application in the markers to predict the activity of glomerular lesions.