Prevalence and clinical relevance of occult hepatitis B in the fibrosis progression and antiviral response to INF therapy in HIV-HCV-coinfected patients

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