Abstract
Occult hepatitis B virus (HBV) infection is diagnosed when HBc antibodies (HBcAb) and HBV DNA are detectable in serum while hepatitis B surface antigen (HBsAg) is not. This situation has been frequently described in patients with chronic hepatitis C virus (HCV) infection. The objective of this study was to evaluate the prevalence of occult hepatitis B in HIV–HCV-coinfected patients and its clinical relevance in liver histology and viral response after interferon therapy for HCV. A total of 238 HIV–HCV-infected patients, negative for HBsAg, were included. Serum samples were analyzed for the presence of HBV DNA and HBcAb. HBV DNA quantification was determined with the Cobas TaqMan HBV Test (detection limit 6 IU/ml). Data from liver biopsy and laboratory tests were also analyzed. HBcAb+ resulted in 142 (60%) patients, being the independent associated factors: male gender, previous history of intravenous drug use, age, CD4 count, and HAV antibody presence. Among 90 HBcAb+ patients that we could analyze, HBV DNA was positive in 15 (16.7% of occult hepatitis B infection in this group, and 6.3% in the whole HIV–HCV cohort studied). No baseline factors, liver histology, or HCV therapy response were related to the presence of HBV DNA. We found that occult hepatitis B is a frequent condition present in at least 6.3% of our HCV–HIV patients and in more than 16% of those with HBcAb+. Despite the high prevalence, this phenomenon does not seem to affect the clinical evolution of chronic hepatitis C or modify the viral response to interferon-based HCV therapies.