Objective: To clarify the relationship between hepatitis B virus (HBV) infection and IgA nephropathy (IgAN).
Methods: HBV antigen (HBAg) in renal tissues of the patients with IgAN was detected by immunohistochemical technique, the carrier status and localization of HBV DNA in renal tissues were determined by Southern blot analysis and in situ hybridization.
Results: Serum HBsAg was detected in 18 of the 100 patients with IgAN (18%), HBAg was detected in 31 of 100 patients (31%) in their renal tissue and in 20 of 31 patients (65%) in their glomeruli, and both HBsAg and HBcAg were detected in 10 of 31 patients (32%), respectively. HBcAg was also found in tubular epithelia (45%, 14/31) and renal interstitium (6%, 2/31), respectively. Five of six cases were proved to be positive of integrated-form HBV DNA in their renal tissue by Southern blot analysis. In situ hybridization demonstrated that HBV DNA was 8/8 and 6/8 positive in their renal tubules and glomeruli of all eight specimens, localized in the nucleus of tubular epithelial cells, glomerular mesangial cells, as well as infiltrated interstitial lymphocytes.
Conclusion: HBV infection closely related with IgAN and HBV infection might be involved in pathogenesis of IgAN.