Occult hepatitis B in HIV-HCV coinfected patients

The prevalence of occult hepatitis B infection in HIV infected patients is controversial, varying from less than 1% to 62% in different studies. Blood samples of 111 HIV-infected patients, HCV-positive, HBs antigen negative, followed in the APROCO-ANRS EP11 cohort, were used to detect HBV DNA by using 2 different validated assays (Cobas Amplicor HBV Monitor Test and INSERM U271 qualitative ultra-sensitive PCR), completed when positive by HBV real-time PCR. HBV DNA was found in 6 (5.4%, 95% CI 1.2%-9.6%) patients by at least 1 of these assays, but none tested positive in all 3 assays. All 6 patients had anti-HBc without anti-HBs antibodies; 5 were not on lamivudine. Their median CD4 and CD8 counts were significantly lower and their HIV viral load higher than in the other 105 patients. In conclusion, the prevalence of occult hepatitis B may vary significantly according to the molecular assay used, even though these assays are validated with high specificity and quite high sensitivity. Occult hepatitis B may be encountered in HIV-HCV coinfected patients without anti-HBV treatment, with anti-HBc but without anti-HBs antibodies, and relatively low immunity, suggesting a potential risk of further reactivation, as already sporadically reported.