The Expression Of Osteopontin And Nf-κb In Renal Tissue Of Lupus Nephritis

Objective:To observe the expression of osteopontin (OPN) and Nuclear Factor Kappa -B (NF-κB) in Renal tissue of lupus nephritis(LN) and to investigate the relationship between OPN and NF-κB with kidney pathology and clinical manifestation.Methods: Renal tissue were assigned to two groups:the lupus nephritis (LN) group and the controlgroup. The 71 renal biopsy specimens were made by renal biopsy from the lupus nephritis patients in Nephrology Department of the first hospital of Anhui medical university from Janury,2006 to July,2010 who diagnosed as systemic lupus erythematosus (SLE) according to the American College of Rheumatology revised criteria for classification of SLE in 1997.All cases were examined by light microscope and immunofluorescence.These cases were divided into four subtypes including 7 LN II,10 LN III ,36 LN IV and 18 LN V according to the classification standard of International Society Nephrology and Renal Pathology Society. The 10 cases normal renal were the tissue far from nephronophthisis or tumor of kidney over 2cm . The expression of OPN and NF-κB were detected by immunohistochemistry in renal tissue of two groups . The relation between OPN and NF-κB, and the associativity between them and histological index, SLE disease activity index serum (SLEDAI), Albumin(Alb), complement ,Serum creatinine (Scr)and 24-hour Urinary protein (24-h UP) were analyzed.Results:(1) OPN was mainly expressed in nephric tubular in renal tissue from normal kidneys and LN, while NF-κB was expressed both in glomeruli and tubulointerstitial area . Compared with the control group, the situ expression of OPN (IV>III>V>II in nephric tubular)and NF-κB(IV>V>III>II in nephric tubular,IV>V>II>III in glomeruli) in the lupus nephritis were higher, especially in type IV. Analysis of variance showed that the difference of OPN in nephric tubular between type IV and type II , III ,V was significance(P≤0.003). Nonparameter test showed that the difference of NF-κB in nephric tubular between type IN and type II ,III ,V was significance(P≤0.043),while the difference of NF-κB in glomeruli between type IV and type II also was significance (P=0.02).(2) The expression of OPN in nephric tubule positively correlated with NF-κB in nephric tubul as well as glomeruli (r=0.446,r=0.473;P<0.001). (3) OPN expression in nephric tubule, NF-κB expression in nephric tubule and gromeruli positively correlated with histological activity index ( r=0.559 ,0.395 ,0.445, P<0.001 ).(4) OPN expression in nephric tubule positively correlated with Scr, 24h-UP and SLEDAI(r=0.337,0.366,0.431,P<0.01),Stepwise regression analysis demonstrated the OPN expression in nephric tubule was closely related to Scr, SLEDAI. NF-κB expression in nephric tubule positively correlated with Scr(r=0.281,P=0.018), NF-κB expression in glomeruli positively correlated with Scr, 24h-UP and SLEDAI (r=0.382,0.320,0.308, P<0.01)and negatively correlated with Alb(r= -0.249,P=0.036), Stepwise regression analysis demonstrated NF-κB expression in glomeruli was closely related to Scr and 24h-UP.Conclusion:(1) The situ expression of OPN and NF-κB in LN are higher than the control group, especially in type IV. OPN and NF-κB play a critical role in the pathogenesis of LN.(2) The expression of OPN and NF-κB positively consist with histological activity index, clinical index of progressive injury and disease activity index in LN.The combination of these two factors detection will provide us a valuable clinical index for renal damage which can offer LN a better treatment regimen and prognosis.