[The relationship between HBV infection and injury of tubuli and interstitium in IgA nephropathy].

OBJECTIVE

To clarify the correlation between HBV infection and the injury of tubuli and interstitium of IgA nephropathy.

METHODS

Renal biopsy specimens from 91 patients with primary IgA nephropathy were investigated by use of in situ hybridization (HBV DNA), immunohistochemistry (HBsAg, HBcAg, CD3, CD8) and HBV DNA, HBAg-CD43 double staining techniques.

RESULTS

The positive rate of HBAg in renal tissue as detected by immunohistochemistry was 69.2% and that of HBV DNA detected by in situ hybridization was 42.9%. Double staining showed that HBV DNA positive tubular epithelial cells might coexpress HBsAg and/or HBcAg. The numbers of the infiltrated CD3+ cells and CD8+ cells in cases with positive HBV infections markers were significantly higher than those of cases without infection (P < 0.01). In addition, CD43+ T lymphocytes infiltrated around or invaded into the tubuli walls which had positive HBcAg or HBsAg expression.

CONCLUSION

After HBV infection, the renal cells could express HBAg and induce infiltration of CD3+ cells and CD8+ cells, resulting in aggravation of the injury of tubuli and interstitium. Therefore, it is considered that HBV infection might play an important role in the occurrence and progress of IgA nephropathy.