IgA肾病患者肾小管间质损伤与胰岛素抵抗的关系

Relationship between insulin resistance and renal tubulointerstitial lesion in IgA nephropathy

目的探讨IgA肾病患者肾小管间质损伤(TIL)与胰岛素抵抗的关系。方法以接受经皮肾活检术确诊的46例IgA肾病患者(IgA肾病组)为研究对象,以10例肾小球轻微病变型肾病综合征患者作为对照。肾组织标本免疫组织化学染色检测肾小球足细胞WT1表达及肾小管间质转化生长因子β_1(TGF-β_1)表达,Katafuchi半定量标准进行TIL分级;放射免疫分析法检测患者尿β_2-微球蛋白水平;根据患者空腹血糖和胰岛素计算胰岛素敏感指数(ISI)。对ISI与TIL分级、肾小管间质TGF-β_1表达和尿β_2-微球蛋白水平进行Spearman等级相关分析。结果与对照组相比,IgA肾病组患者ISI降低,肾小球足细胞WT1表达减少,肾小管间质TGF-β_1表达增加(均P<0.01)。相关性分析显示,IgA肾病患者ISI与TIL分级、肾小管间质TGF-β_1表达及尿β_2-微球蛋白水平呈负相关,与肾小球足细胞WT1表达呈正相关。结论 IgA肾病TIL程度与患者胰岛素抵抗呈正相关,提示改善胰岛素抵抗有助于延缓IgA肾病的进展。

Objective To investigate the relationship between renal tubulointerstitial lesion （TIL） and insulin resistance in IgA nephropathy. Methods Forty-six patients with IgA nephropathy diagnosed by renal biopsy were involved （ IgA nephropathy group）, and another 10 patients with minimal change nephrotic syndrome were served as controls. The expression of WT1 of glomerular foot cells and transforming growth factor-β_1 （TGF-β_1） of renal tubulointerstitium in renal tissue samples was detected by immunohistochemical staining, and TIL was classified by Katafuchi half-quantity criteria. The level of urinary β_2-microglobulin was measured by radioimmunoassay. The insulin sensitivity index （ ISI） was calculated according to the levels of fasting blood glucose and insulin. The correlation between ISI and TIL classification, expression of TGF-β_1 in renal tubulointerstitium and level of urinary β_2 -microglobulin was analysed by Spearman rank correlation analysis. Results Compared with control group, ISI and expression of WT1 of glomerular foot cells of IgA nephropathy group were lower, and expression of TGF-β_1 in renal tubulointerstitium was higher （P 〈0. 01 for all）. Correlation analysis revealed that ISI was negatively related to TIL classification and expression of TGF-β_1 in renal tubulointerstitium, and was positively related to expression of WT1 of glomerular foot cells. Conclusion TIL is positively related to insulin resistance of IgA nephropathy, indicating that improving insulin resistance may postpone the progression of IgA nephropathy.