Background:  Occult hepatitis B virus (HBV) infection is defined as the presence of HBV DNA in the serum or liver tissue in the absence of HBV surface antigen (HBsAg). The clinical significance of occult HBV among HIV patients remains unclear. We examined whether HIV patients with occult HBV had a greater incidence of transaminitis over time than those without occult HBV.

Methods:  We performed a cohort study among a random sample of HBsAg^–/HBV core antibody positive (anti-HBc⁺) HIV patients in the Penn CFAR Database and Specimen Repository. Exposure status was defined by HBV viremia, qualitatively evaluated using a transcription-mediated amplification assay (lower limit of detection: 15 HBV copies/mL). The primary outcome was transaminitis, defined as either alanine aminotransferase (ALT) >40 U/L or aspartate aminotransferase (AST) >30 U/L. The first ALT and AST within each half-year of a subject’s follow-up were selected. Among subjects without baseline transaminitis, incidence rate ratios (IRR) of transaminitis between subjects with and without occult HBV were calculated. Poisson regression was used to control for confounders.

Results:  Among 97 HBsAg^–/anti-HBc⁺ subjects without baseline transaminitis, 13 (13%) had occult HBV. These subjects were older, more frequently had detectable HIV viremia, and less commonly received anti-HBV ART than those without occult HBV. The median duration of follow-up from HBV DNA testing was 25.2 months (IQR 17.1 to 30.4). Transaminitis occurred at least once in 11 (85%, 95%CI 55 to 98%) occult HBV subjects compared to 66 subjects without occult HBV (79%, 95%CI 68 to 87%, p >0.5). The incidence of transaminitis among subjects with occult HBV (50 events/100 person-years) was not significantly different from the incidence among those without occult HBV (38 events/100 person-years; IRR = 1.32, 95%CI 0.63 to 2.53, p >0.5). The IRR changed little after adjusting for self-reported alcohol use, HAART, and chronic hepatitis C virus (HCV) infection (IRR = 1.36, 95%CI 0.72 to 2.59).

Conclusions:  The incidence of transaminitis over a 2-year period was not significantly increased with occult HBV, even after adjusting for alcohol use, HAART, and chronic HCV, suggesting that it has little short-term clinical effect among HIV patients. Additional studies should examine whether occult HBV is associated with hepatic fibrosis and hepatocellular carcinoma in HIV patients.