The Relationship Between HBV Infection And Tubulointerstitial Lesions Of Lupus Nephritis

Objective To examine the expression of HBsAg,HBcAg and existence of HBV DNA in renal tissue of lupus nephritis (LN).To compare the degree of tubulointerstitial lesions(TIL) and tubulointerstitial infiltration of CD4~+,CD8~+ and CD68~+ (monocyte/macrophage) cells between renal HBV antigen (HBAg) positive groups and negative groups,to explore the relationship between HBV infection and injury of tubuli and interstitium of LN.Methods HBsAg,HBcAg and infiltration of CD4~+,CD8~+ and CD68~+cells in renal biopsy specimens from 44 cases of LN were detected using Envision immunohistochemical techniques.Nine cases of renal tissue were examined for HBV DNA by means of Fluorescence Quantitative Polymerase Chain Reaction (FQ-PCR).The semi-quantitative methods were adopted to evaluate TIL. Paired test was performed to analyze the correlation between HBcAg and the infiltrated inflammatory cells in tubulointerstitium of LN.Results The positive rate of the expression of HBAg in LN renal tissues was calculated to be 59.09%(26/44).The picking out rate of HBcAg was higher than that of HBsAg. HBcAg deposited in the tubular epithelial cells was more obvious than in the glomerulus.All of 9 cases showed HBV DNA negative by FQ-PCR.The degree of TIL and the numbers of the infiltrated CD4~+,CD8~+ and CD68~+cells were not significant between renal HBAg positive groups and negative groups(P>0.05). Contrary to the control group ,the degree of renal tubuli lesions and tubulointerstitial inflammation of positive groups were significantly more serious (P<0.05). The numbers of the infiltrated CD8(~+P<0.01) and CD68~+cell(sP<0.001) in HBAg positive group and CD68~+cells (P<0.01)in negative group was significantly more than control group. The numbers of the infiltrated CD68~+cells in tubuli and interstitium of LN was significant between HBcAg positive group and negative group(P<0.05).Conclusions The results indicated that there is a higher infection percentage of HBV in LN.The existence of HBcAg in tubular epithelial cells of LN has a great significance.The infiltration of monocytes/macrophages in LN tubulointerstitiums may be correlated with the existence of HBcAg, and tubular epithelial cells with HBcAg may be the target cells of celluar immunity.Whether HBV infection play an important role in the pathogenesis of tubulointerstitial lesions and HBAg could induce infiltration of T-Lymphocytes and macrophages resulting in aggravation of the injury of tubuli and interstitium should still waite for further studies.