Characteristics and prevalence of occult hepatitis B virus infection in patients with hepatitis C in Iran

Hepatitis B virus (HBV) infection in patients who lack detectable hepatitis B surface antigen (HBsAg) is called occult hepatitis B infection. Such infections have been frequently identified in patients with chronic hepatitis Cliver disease, but their prevalence is not known.Methods: 207 patients with chronic hepatitis C who were HCV -RNA and antiHCV positive were studied for HBV-DNA by PCR, and for HBsAg and anti-HBc by ELISA. DNA was extracted by high pure nucleic acid kit (Roche-Germany). HBVDNA amplification was done with a set of primer directed to the pre-S region. HBsAg and anti-HBc were evaluated by a commercially available ELISA kit (Dade Behring). Results: 23 of 207 patients with chronic hepatitis Cliver disease ( 11.1%) were positive for HBV-DNA (co-infection). Among this group 17 patients (8.2%) were HBsAg negative (occult infection). 8 of 17 patients with occult infection ( 4 7%) were anti-HBc positive and 9 were anti-HBc negative (53%). No significant difference was found in epidemiological and biochemical parameters in patients with HCV alone in comparison with HCV co-infected with occult hepatitis B (p= 0.453 for ALT and p= 0.498 for AST).Conclusion: Occult hepatitis B virus infections occur frequently in patients with chronic hepatitis Cliver disease and may have clinical significance.