Occult hepatitis B infection in HIV-positive individuals is associated with a low CD4 cell count and a high HIV viral load, according to Dutch data presented to the 3rd International Workshop on HIV and Hepatitis Coinfection in Paris on June 8th. The investigators in Utrecht also established that a prevalence of occult hepatitis B infection of 5% in HIV/hepatitis B coinfected individuals.
Occult, or hidden hepatitis B infection, is defined as the presence of hepatitis B’s DNA and core antibodies in plasma, but without hepatitis B surface antigen. Earlier studies have suggested that it is presented in between 0% and 89% of HIV/hepatitis B infected individuals, the large difference due to different testing techniques and study populations.
To try and establish a more reliable indication of the prevalence and risk factors of occult hepatitis B infection in HIV coinfected patients, investigators at the university of Utrecht conducted a retrospective study involving patients who received care between 1999 and 2006.
A total of 197 HIV/hepatitis B coinfected individuals were included, 32 of whom were also infected with hepatitis C virus. Median CD4 cell count was 317 cells/mm3 and median HIV viral load was 85,000 copies/ml.
Occult hepatitis B infection was diagnosed in nine individuals (5%). It has been suggested that infection with hepatitis C virus is associated with an increased risk of occult hepatitis B, but only one patient who had hepatitis C virus had occult hepatitis B.
Patients with occult hepatitis B infection had significantly lower CD4 cell counts (median 105 cells versus 323 cells/mm3, p = 0.01), and significantly higher HIV viral loads (median 5.5 log10 versus 4.9 log10, p = 0.019). The investigators suggest that these clinical characteristics suggest that occult hepatitis B could be considered an ‘opportunistic infection’ as it occurred in patients with immune deficiency.
None of the patients with occult infection were taking antiretroviral therapy at baseline. The initiation of anti-HIV therapy lead to a median increase of CD4 cell count to 300 cells/mm3 over three years and all the patients hepatitis B infection became well controlled, either because the patients were taking an antiretroviral drug with activity against hepatitis B (3TC, FTC, or tenofovir), or because of improving immune function.
Velemena M et al. Occult HBV in HIV infected individuals is related to low CD4 count and high plasma HIV load. Third International Workshop of HIV and Hepatitis Coinfection, Paris, abstract 32, 2007.