Occult HBV infection among anti-HBc positive HIV-infected patients in apex referral centre, Eastern India

Background. The prevalence of occult HBV, defined by the presence of HBV DNA in individuals with anti-bodies to HBV core antigen and with absence of HBV surface antigen, but its clinical significance and viro-logical features in HIV-infected patients is still unclear. Aim. To investigate the prevalence, clinical significance and molecular characterization of occult hepatitis B virus infection in ART-Naive HIV-positive individuals. Material and methods. Among the 1077 HIV-infected patients with different risk factors for HIV infection, 297 were HBsAg-ve ART-naive, of them 112 was randomly selected for the study. HBV DNA was tested by in-house PCR and quantified by qPCR. Molecular characterization was performed by sequencing the envelope and overlapping polymerase genes. Results. We found the prevalence of occult HBV to be 10.7% among a randomly selected group of HBsAg-ve/antiHBc+ve HIV-infected patients. Overall 33.9% (38 of 112) of the patients were antiHBc positive indicating exposure to HBV infection. HBV DNA was detected in 12/38 (31.5%) antiHBc positive samples and 50% of them had CD4 T cell count < 200 cells/mm³. HCV coinfec-tion was low (2.7%). No surrogate marker for OBI could be identified. Presence of antiHBs antibodies did not rule out OBI. Liver biopsy in six cases showed varying stages of chronic hepatitis. Several mutations were detected but not the common immune escape mutant G145R. Conclusion. In conclusion the preva-lence of OBI was significantly high among HIV coinfected patients, which highlights the importance of HBV DNA testing in these patients and indicates need for further prospective studies in larger cohorts to assess its clinical significance.