Background: Hepatitis B virus infection has re-emerged as an important cause of morbidity/mortality in HIV-infected patients (pts). The prevalence of hepatitis B infection in a nationally representative HIV-infected cohort has not been previously described. There is considerable controversy regarding the significance of “occult” (anti-HBc⁺, HBV DNA⁺) hepatitis B in HIV-infected pts. We sought to determine the prevalence of active HBV and occult HBV infection in the AACTG.

Methods: A random sample of subjects from ACTG 320 and 343 were selected for evaluation of hepatitis B markers, including anti-HBc (IgG and IgM), anti-HBs, HBsAg, (Abbott, N. Chicago, IL) and HBV DNA (bDNA, Bayer, Tarrytown, NY). Samples were collected prior to initiation of highly active anti-retroviral therapy (HAART). Sample size was approximated by estimation of the prevalence of occult hepatitis B in the cohort.

Results: We identified 240 representative samples. The median age was 37 (range 20–75) yrs. Fifty percent (50%) were Caucasian, and 83% were male. Median CD4⁺ count was 137 (range 0–856) cells/mm³. Of the samples, 156 (65%) demonstrated evidence of either past hepatitis B exposure or active hepatitis B infection. Of those, 92 samples (38.3%) demonstrated typical markers of hepatitis B infection and clearance (anti-HBs⁺, anti-HBc⁺, and HBsAg^-). These samples were all HBV DNA negative. Six (6; 2.5%) samples displayed markers consistent with prior vaccination (only anti-HBs⁺). These were also HBV DNA^-. Seventeen (17; 7.1%)samples were positive for anti-HBc and for HBsAg, consistent with acute or chronic infection. Ten (10) of these were positive for HBV DNA. Their median HBV viral load was 844.8 MEq/ml. Thirty-eight (38; 15.8%) subjects demonstrated an “occult” marker pattern characterized by only anti-HBc reactivity. Only one “occult” sample had detectable HBV (1,831 MEq/ml).

Conclusions: The majority of HIV-infected pts enrolled in a nationally distributed study cohort have evidence of current or past HBV infection. HBV infection with active viremia is more prevalent in this cohort when compared to the general population and is characterized by high viral loads in nearly 60% of HBsAg⁺ individuals. Prevalence of hepatitis B anti-core alone is lower than has been described for European cohorts, and only 2.6% had evidence of highly replicative HBV infection.