characteristics and prevalence of occult hepatitis b virus infection in patients with hepatitis c in iran

abstract background: 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.