The Expression And Significance Of Osteopontin In IgA Nephropathy

Objective:To investigate the relationship between Osteopontin(OPN) and IgA Nephropathy(IgAN) patients tubulointerstitial lesion(TIL).In order to investigate the significance and mechanism of OPN in TIL,We study the relationship among the expressions of OPN in renal tissue of patients with IgAN,clinical manifestation and the degree of tubulointerstitial lesion.Methods:The expression sites and levels of OPN in 36 renal tissue of patients with IgA Nephropathy and 5cases of normal control group were detected by immunohistochemical staining and computering analysis system.We also examined the relationship between the expression of OPN in renal tubulointerstitial area and possible associated clinical datum.Results:1) Clinical data:With the aggravation of tubulointerstitial lesion,Upro in severe pathological change group was obviously higher than in mild and midrange pathological change groups(P＜0.01).2) Hemiquatitate score was used for TIL.The index of TIL in mild pathological change group was 0.There was no significant difference between mild pathological change group and control group.The index of TIL in midrange and severe pathological change group was higher than mild pathological change group(P＜0.01).3) OPN was mainly expressed in endochylema of proximal convoluted tubular epithelial cell in renal biopsies from normal kidneys and IgA nephropathy. No expression in glomeruli,renalinterstitium and inflammatory cells.In renal biopsies from normal kidneys,OPN expression was barely detectable.There was significant difference between control group and IgAN groups(P＜0.01).4)Compared with the control group,OPN expression was significantly increasing in mild group,midrange group and severe group(P＜0.01).With the progression of TIL,the expression of OPN increased gradually.It was significantly different between mild and midrange pathological chang groups(P＜0.01).With the aggravation of TIL,renal interstitium fibrous,renal tubule atrophia and inflammatory cells infiltration were increased,but the expression of OPN decreased gradually.It was significantly different between severe pathological change group and mild,midrange pathological change groups (P＜0.01).5) And the index of TIL also had positive correlation with the expression of OPN(r=0.775;P＜0.01) in mild and midrange IgA nephropathy.The degree of OPN expression in patients with IgAN had positive correlation with the serum creatinine level,blood pressure,and proteinuria(r=0.632,0.546,0.454;P＜0.05).No correlation was found between the expression of OPN and serum cholesterol and triglyceride in IgA nephropathy.Conclusion:1)OPN was mainly expressed in tubular epithelial cell in renal tissue from normal kidneys and IgA nephropathy.2)In renal tissue from normal kidneys,the expression of OPN could be detected a little.With the aggravation of TIL,OPN expression was increased in renal biopsies from IgA nephropathy patients.But OPN expression was decreased in severe pathological change group.3) The expression level of OPN and TIL presented positive correlation, we presume that OPN as a role may participate in tubulointerstitial fibrosis of IgAN. 4)OPN is considered of a early sign of TIL,so it provides a new way for delaying the progress of IgAN.5)Renal tubulointerstitial injury is important to judge the disease condition,prognosis and clinical treatment.