Prevalence and time course of hepatitis B virus infection in patients with systemic lupus erythematosus under immunosuppressive therapy

Objective To clarify the prevalence and time course of hepatitis B virus (HBV) infection in patients with systemic lupus erythematosus under immunosuppressive therapy. Methods We performed serological examination of 248 lupus patients to determine the presence of HBV, including hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc). Serum HBV DNA levels were measured in HBsAg-positive patients or resolved HBV carriers (HBsAg-negative, anti-HBs-positive, and/or anti-HBc-positive). If possible, we repeatedly performed examination of markers of HBV infection in resolved carriers. Results Two (0.8 %) patients were positive for HBsAg. Among 41 (16.5 %) patients who were considered as resolved HBV carriers, 1 (2.4 %) showed serum HBV DNA, which indicated occult HBV infection. The mean age and positive rate of anti-double stranded DNA antibody were significantly higher in resolved carriers than in anti-HBs- and anti-HBc-negative patients. Repeated examination showed that the anti-HBs and anti-HBc titer decreased below the threshold in 4 resolved carriers. Conclusions The prevalence of resolved HBV carriers in Japanese lupus patients was 16.5 %. Among them, occult HBV infection and decrease in anti-HBs and anti-HBc titer were observed. These findings indicated that all lupus patients should undergo serological examination for HBV before treatment. If patients have already been treated, we must carefully monitor their liver function, even when all HBV markers are negative.