IgA肾病患者纤溶酶原激活物的变化及临床意义

目的：探讨IgA肾病患者纤溶酶原激活物（PA）的变化及临床意义。方法：以纤维蛋白平板法检测108例IgA肾病及34例健康自愿者尿PA活性,同时以免疫组化方法观察了27例IgA肾病及6例正常人肾组织t-PA、u-PA抗原表达,分析其与临床病理资料的关系。结果：正常人肾组织t-PA偶见少量表达于肾小球毛细血管袢,u-PA则表达于所有节段的肾小管上皮细胞。IgA肾病肾组织t-PA阳性率及单个肾小球t-PA平均积分明显高于正常人。轻度增生的肾小球其t-PA阳性率明显增高,中度增生的肾小球t-PA阳性率明显高于轻度增生者,硬化的肾小球不表达t-PA。u-PA表达明显下调,尿PA活性下降。伴血肌酐升高、肾小管间质病变严重、肾小动脉病变较重或大量蛋白管型形成的患者尿PA活性下降更为明显。结论：IgA肾病早期肾组织t-PA表达增加,晚期下降。肾组织u-PA表达减少。蛋白管型的形成可能与尿PA活性下调有关。尿PA活性的检测有助于判断IgA肾病的病情。

The changes of plasminogen activators in patients with IgA nephropathy and their clinical significance

Purpose To find out the changes of plasminogen activators(PA)in IgA and their clinical significance. Methods In the present study, urinary activity of PA was determined by fibrin plate method.Urine samples were collected from 108 patients with IgA nephropathy and 34 healthy volunteers. The immunohistochemical study of tissue type PA(t PA) and urokinase type PA(u PA) was carried out,using renal biopsy specimens obstained from 27 patients with IgA nephropathy and 6 normal renal transplant donator. The relationships between PA and clinico pathological features were analysed. Results The t PA antigen was rarely found in normal renal tissue and weakly distributed along the glomerular capillary walls. But u PA antigen was strongely presented in all segments of the tubular epithelium. In IgA nephropathy, the positive rate of t PA antigen and the average score of t PA in each glomerulus were higher than those in normal control. The positive rate of t PA antigen in mild proliferative glomeruli was significantly higher than that in normal glomeruli. The positive rate of t PA antigen was higher in moderate proliferative glomeruli than that in mildproliferative glomeruli. The sclerosis glomeruli did not express t PA. The expression of u PA antigen in IgA nephropathy was much lower than that in normal control. Meanwhile,the activity of PA in urine in IgA nephropathy was also significantly lower than that in healthy volunteers. The activity of urinary PA was decreased much more in patients with abnormal level of serum creatinine,serious tubulo interstitial demage, obvious renal arteriolar lesion or abundent urinary protein cast in renal tubule than that in patients without those clinical or pathological features. Conclusions The results suggested that the expression of t PA antigen increases in early stage of IgA nephropathy and decreases in advanced stage. The expression of u PA decreases. The formation of urinary protein castin in renal tubule may be asssociated with the decrease of urinary PA activity. The determination of urinary PA activity is useful in evaluating the state of IgA nephropathy.