一种成人肾病综合征患者尿沉渣足细胞分子nephrin及Podocalyxin检测方法

目的:探讨采用ELISA方法以尿AQP(Aquaporin)-2校正检测肾病综合征尿nephrin podocalyxin排泌,以帮助评估成人肾病综合征的诊断和病情。方法:入组71例经肾穿刺明确病理诊断的成人肾病综合征(NS)患者,包括20例增殖性肾小球疾病的患者,49例非增殖的患者和2例淀粉样变性患者。22例FSGS患者(其中13例确定FSGS亚型诊断)。选取10例健康志愿者作为研究对照组。用ELISA法测定尿nephrin,podocalyxin和AQP-2。以尿AQP2作为内参照校正尿nephrin(neph/AQP)和podocalyxin(PCX/AQP)。结果:尿neph/AQP和PCX/AQP正相关(R=0.616,P<0.001),正常人尿neph/AQP和PCX/AQP显著低于NS患者(P<0.05),增殖和非增殖性肾病综合征患者的尿neph/AQP和PCX/AQP差异无统计学意义(P>0.05),FSGS患者尿neph/AQP和PCX/AQP中显著高于其他NS患者(P<0.05),在IgMN患者尿neph/AQP和PCX/AQP增加,肾淀粉样变性患者的尿neph/AQP和PCX/AQP较少。对13例明确FSGS病理亚型诊断的患者尿neph/AQP和PCX/AQP进行评估,发现各组间差异无统计学意义(P>0.05),但以细胞型FSGS尿neph/AQP排泌最高,NOS型其次,顶端型再次,以脐部型最低。尿PCX/AQP则以细胞型FSGS排泌最高,NOS型其次,脐部型再次,顶端型最低。对于肾病综合征患者FSGS的诊断,ROC曲线分析表明,当尿neph/AQP取临界值为0.165时其灵敏度为0.864,而特异性为0.603,尿PCX/AQP取临界值3.056时其灵敏度为0.773,特异性为0.672。结论:采用ELISA方法的以AQP-2作为内参检测成人肾病综合征尿足nephrin,podocalyxin较为简便。IgMN患者尿neph/AQP和PCX/AQP增高,肾淀粉样变性患者的尿neph/AQP和PCX/AQP较低。FSGS患者尿neph/AQP和PCX/AQP高于其他肾病综合征患者,在FSGS亚型中以细胞型及NOS型稍高于其他亚型FSGS患者,该方法还有助于在临床肾病综合征患者中帮助诊断FSGS。

ELISA Analysis of Urinary Nephrin and Podocalyxin Standardized by AQP -2 in the Adult Patients with Nephrotic Syndrome

Objective:To investigate the urinary nephrin and podocalyxin excretion standardized by AQP-2 using ELISA method in the adult nephrotic syndrome patients.Methods:71 adult nephrotic syndrome patients undergoing renal biopsy,including 20 proliferative nephritis patients,49 non-proliferative patients and the two amyloidosis patients.In the 22 FSGS patients,we obtained variants diagnoses in 13 cases.Ten healthy persons were enrolled in this study as the control group.Urinary nephrin,podocalyxin and AQP-2 were measured using ELISA method.Urinary nephrin and podocalyxin were standardized by AQP-2(neph/AQP and PCX/AQP).Results:Urinary neph/AQP correlated positively to PCX/AQP(r=0616,P<0.001).Urinary neph/AQP and PCX/AQP were the lowest in the normal persons as compared with the nephrotic syndrome patients.FSGS patients excreted higher neph/AQP and PCX/AQP in the urine than those in the other patients(P<0.05).Urinary neph/AQP and PCX/AQP were increased in the IgMN patients.Amyloidosis patients excreted less neph/AQP and PCX/AQP.In the 13 FSGS patients,there is no significant difference among these variants(P>0.05).However,Both urinary neph/AQP and urinary PCX/AQP was the highest in the cellular variant.Then urinary neph/AQP was decreased gradually as the sequence as NOS,tip lesion and perihilar variant..Urinary PCX/AQP was decreased gradually as the sequence as NOS,perihilar variant and tip lesion.For the diagnosis of FSGS,a ROC curve analysis indicated that the sensitivity value is 0.864 while the specificity value is 0.603 when the urinary neph/AQP borderline value was 0.165,and the sensitivity value is 0.773 while the specificity value is 0.672 when the urinary PCX/AQP borderline value was 3.056.Conclusion:It was convenient to measure urinary podocyte using ELISA method standardized by AQP-2 in the adult nephrotic syndrome patients.Urinary neph/AQP and PCX/AQP were both significantly increased in the proliferative and the non-proliferative glomerulonephritis patients without a significant difference between them.Urinary neph/AQP and PCX/AQP in the renal amyloidosis patients were.FSGS patients excreted higher neph/AQP and PCX/AQP.It’s also practical to discern FSGS patients from other nephrotic syndrome patients using this method.