THE CHANGES OF PLASIMINOGEN ACTIVATORS IN PATIENTS WITH IGA NEPHROPATHY AND THEIR CLINICAL SIGNIFICANCE

Objective To find out the changes of plasminngen activators(PA)in IgA nephropathy(IgAN)and their clinical sig-nificance.Methods In the present study,urinary activity of PA was determined by fibrin plate method.Urine samples were collected from108 patients with IgAN 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 tom 27 patients with IgAN.The relationships between PA and clinico-pathological features were analysed.Resnlts The t-PA antigen was rarely found in normal renal tissue and weakly distributed along theglomerular capillary walls,but u-PA antigen was strongely present in all segments of the tubular epithelium.In IgAN.the positive rate oft-PA antigen and the average score of t-PA in each glomerulus were higher than those in normal control.The positive rate of t-PAantigen in mild-proliferative glomeruli was significantly higher than that in normal glomeruli.The positive rate of t-PA antigen washigher in middle-proloferative glomeruli than that in mild-proliferative glomeruli.The sclerosis glomeruli did not express t-PA.Theexpression of u-PA antigen in IgAN was much lower than that in normal control.Meanswhile,the activity of PA in urine in IgAN wasalso significantly lower than that in healthy volunteers.The activity of urinary PA was decreased much more in patients with abnormal levelof serum creatinine、serious tubulo-interstitial dernage、obvious renal arteriolar lesion or abundent urinary protein cast in renal tubulethan that in patients without those clinical or pathological features.Conclusion The results suggested that the expression of t-PA antigenincreases in early stage of IgAN and decreases in advanced stage.The expression of u-PA decreases.The formation of urinary protein castin renal tubule may be asssociated with the decrease of urinary PA activity.The determination of urinary PA activity is useful in evaluatingthe state of IgAN.