尿足细胞数量及podocalyxin蛋白与IgA肾病的相关性

Correlation of urinary podocyte count and podocalyxin level with IgA nephropathy

目的探讨尿足细胞数量和podocalyxin蛋白表达与IgA肾病发病、发展的相关性,探索IgA肾病的诊断、病情和预后评估提供的新指标。方法采用间接免疫荧光法检测陕西省第四人民医院体检的健康人群和150例IgA肾病患者尿足细胞数量及podocalyxin蛋白表达水平,观察健康人群和IgA肾病患者尿足细胞数量差异和不同肾脏病理Lee分级IgA肾病患者尿足细胞数量和podocalyxin蛋白表达水平差异,分析不同肾脏病理Lee分级IgA肾病患者尿足细胞数量和podocalyxin蛋白表达与肾小球滤过率、24 h尿蛋白定量、血清肌酐、尿素氮等临床指标的相关性。结果健康人群组尿沉渣细胞涂片染色标本未见尿足细胞,而IgA肾病组尿沉渣细胞涂片染色标本尿足细胞数量为每20个高倍视野(12.54±2.89);不同肾脏病理Lee分级IgA肾病患者的尿足细胞数量、podocalyxin蛋白表达和24 h尿蛋白定量比较,差异有统计学意义(P<0.05),且不同肾脏病理Lee分级IgA肾病患者尿足细胞数量与24 h尿蛋白定量呈正相关(r=0.835 3,P<0.05),podocalyxin蛋白表达与24 h尿蛋白定量呈负相关(r=0.886 8,P<0.05)。结论尿足细胞数量、podocalyxin蛋白表达与IgA肾病的发病、发展密切相关。

Objective To investigate the correlation of the number of urinary podocytes and the expression level podocalyxin with the occurrence and development of IgA nephropathy so as to explore new markers for the assessment of the diagnosis, condition and prognosis of the disease. MethodsA total of 150 patients with identified IgA nephropathy admitted in Fourth People’s Hospital of Shaanxi Province in 2016 were enrolled in this study and assigned into observation group. Another 150 sex- and age-matched healthy individuals who took physical examination in the same hospital during the same period served as control group. Indirect immunofluorescence assay was used to measure the number of podocytes and level of podocalyxin protein in the urinary samples from the observation and control groups. The results were compared between the 2 groups, among the IgA nephropathy patients with different grades of kidney pathology Lee classification. The correlations of urinary podocyte numbers and podocalyxin levels in the patients with different Lee grades were analyzed with the glomerular filtration rate, 24 h urinary protein, serum creatinine and urea nitrogen. ResultsNo podocytes were observed in the urine sediment smear from the healthy individuals, and the number was 12.54±2.89 （per 20 high power field） in the observation group. Significant differences were found in the podocyte number, podocalyxin protein level, 24 h urinary protein among the patients at different Lee grades （P〈0.05）. In the patients of different Lee grades, the urinary podocyte count was positively correlated with the 24 h urine protein（r=0.835 3, P〈0.05）, while podocalyxin protein expression was negatively correlated with 24 h urine protein（r=0.-0.886 8, P〈0.05）. ConclusionUrinary podocyte count and podocalyxin protein level are closely related to the occurrence and development of IgA nephropathy.