Background: Co-infection of HIV⁺ patients with hepatitis B virus (HBV) constitutes a risk to hepatotoxic reactions and possibly long-term liver damage. Flares of hepatitis due to HBV reactivation has been described in a number of case reports. Longitudinal studies on HBV serum markers has not been systematically investigated yet.

Methods:  All patients that ever attended the HIV clinic of the Bernhard Nocht Institute and who were positive for HBV core antibodies (anti-HBc) at least once were eligible for a retrospective analysis over 20 years (1983 to 2003). HBs antigen (HBsAg) and HBs antibodies (anti-HBs) were measured from samples stored at -80°C at least in the first and last available serum sample, at times of HIV treatment change, and in-between, if a change of the serostatus was observed.

Results:  Of 504 eligible patients, 384 had at least 2 serum samples and clinical data available more than three months apart. In the latter subgroup, HBs-Ag was negative in 61.2% and positive in 13%. A seroconversion from HBs-Ag negative to positive occurred in 12% and vice versa in 4.4%. Fluctuating detection of HBs-Ag in both directions was detected in 9.4%. These figures were observed for anti-HBs in 42.2%, 41.9%, 2.1%, 8.9%, and 4.2%, respectively. There was a statistically significant correlation with hepatitis C virus antibody status (anti-HCV), such that in anti-HCV positive patients anti-HBs (p <0.001) as well HBs-Ag (p = 0.011) was less frequent as compared to anti-HCV negative patients. The serum of four patients without signs of acute hepatitis was initially negative for anti-HBc. Three of them were HBs-Ag positive, one anti-HBs positive, and all HBV DNA positive. Three patients experienced a severe hepatitis, followed by development on HBs antibodies.

Conclusions:   Changes of the hepatitis B serostatus in HIV-infected patients is an unanticipated frequent phenomenon. This raises interesting questions on the hepatitis B immunology in HIV infection. With respect to the hepatotoxic potential, repeated measurements of hepatitis B markers should be considered.

Keywords: hepatitis B; hepatitis C; serostatus