IgA肾病系膜细胞-足细胞轴在肾小管间质病变中的作用

摘要

Purpose To investigate the role of mesangial cells and podocyte axis in the renal tubulointerstitial lesion in IgA nephropathy. Method Forty cases of IgA nephropathy diag-nosed by renal biopsy were analyzed. The expression of WT-1, a specific marker of podocyte surface, TNF-a and IL-6 in renal tissue was observed by immunohistochemistry, and the activity of TNF-a and IL-6 in urine was detected by enzyme-linked immu-nosorbent assay (ELISA). Results The glomerular mesangial proliferation score was negatively correlated with the expression of WT-1 in IgA nephropathy (r =-0.763, P＜ 0.05), and positively correlated with the expression of renal tissue TNF-a and IL-6, urine TNF-a and IL-6 activity levels in IgA nephropathy (r =0.674, r=0.853, r =0.819, r=0.763, all P＜0.05). With the aggravation of renal tubulointerstitial lesions in IgA nephropathy, the expression of WT-1 decreased gradually, while the expression of TNF-a and IL-6 in renal tissue increased gradually, and the activity of TNF-a and IL-6 in urine increased gradually (P＜ 0.05). The expression of WT-1 was negatively correlated with renal tissue IL-6 expression, TNF-α expression, urine IL-6 activity level, and urine TNF-a activity level (r =-0.603, r =-0.564, r =-0.563, r =-0.544, all P＜0.05), and it was positively correlated with the urine osmotic pressure (r = 0.821, P＜ 0.05 ) and positively correlated with the degree of renal tubular interstitial damage (r = 0.793, P＜0.01). Conclusion The cytokines produced by mesangial cell proliferation of IgA nephropathy play a role in podocyte and in-duce podocyte apoptosis and aggravate tubulointerstitial injury.%目的 探讨IgA肾病系膜细胞-足细胞轴在肾小管间质病变中的作用.方法 收集40例经肾穿刺活检明确诊断的IgA肾病,采用免疫组化法检测足细胞表面特异性标志物WT-1、肾组织TNF-α、IL-6的表达;采用酶联免疫吸附法测定患者尿 TNF-α、IL-6的活性水平.结果 IgA肾病患者肾小球系膜增生评分与WT-1的表达呈负相关(r=-0.763,P＜0.05),与肾组织 TNF-α 及 IL-6表达、尿液 TNF-α 及 IL-6活性水平均呈正相关(r =0.674、r =0.853、r =0.819、r=0.763,P均＜0.05),IgA肾病患者随肾小管间质病变加重,肾组织WT-1的表达逐渐降低;而TNF-α、IL-6的表达逐渐升高,且尿液TNF-α、IL-6的活性水平逐渐升高(P＜0.05).肾组织WT-1表达与肾组织IL-6、TNF-α表达及尿液IL-6、TNF-α活性水平均呈负相关(r=-0.603=-0.564、r=-0.563、r=-0.544,P均＜0.05),与尿渗透压呈正相关(r=0.821,P＜0.05),且与肾小管间质损害程度分级呈正相关(r=0.793,P＜0.01).结论 IgA肾病系膜细胞增殖产生的细胞因子作用于足细胞并诱导足细胞凋亡、加重肾小管间质损伤.