Studies Examine Occult HBV Infection and Effect on Liver Disease in HIV Positive and HIV-HCV Coinfected Patients

Past research has produced conflicting data concerning the prevalence of "occult" or hidden hepatitis B virus (HBV) infection in people with HIV, and what, if any, is its clinical significance. Occult HBV refers to the unusual discordant patterns of specific HBV antigens, antibodies, and/or HBV DNA.

Two such studies were presented at the recent 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention in Sydney, Australia (July 22-25, 2007).

Study 1

In the first study, Spanish researchers evaluated blood samples from 2577 HIV negative and 151 newly diagnosed HIV positive individuals tested for HBV. Complete analytical confirmatory testing was performed for patients with isolated hepatitis B core antibodies (anti-HBc).

Results

• Among the HIV negative subjects, 340 (13%) had evidence of HBV infection, and 46 of these (14%) had an isolated anti-HBc pattern.

• Among the HIV positive subjects, 70 (47%) had HBV infection, of whom 31 (44%) had an isolated anti-HBc pattern.

• Among the patients with isolated anti-HBc, detectable hepatitis C virus (HCV) antibodies were significantly more common in the HIV positive compared with the HIV negative subjects (79% vs 56%).

• HIV-HCV coinfected individuals were significantly more likely to have isolated anti-HBc than HIV positive subjects without HCV (77% vs 23%).

• Liver disease was more frequent in HIV positive compared with HIV negative subjects (26% vs 13%).

• All patients with liver disease had HCV coinfection.

"Patients with HIV infection have a higher rate of isolated anti-HBc than HIV negative patients, usually associated with anti-HCV antibodies," the researchers concluded. "In both groups, significant hepatic disease was detected only when HCV coinfection was present."

Study 2

In the second study, Polish researchers assessed the presence of hepatitis B surface antibodies (anti-HBs) and HBV DNA in 65 patients who were had anti-HBc antibodies but were hepatitis B surface antigen (HBsAg) negative. The study included:

• 25 subjects with HCV monoinfection;

• 17 subjects with HIV-HCV coinfection;

• 23 subjects with neither HIV nor HCV.

Results

• The researchers found no relationship between patient demographic variables and any of the analyzed HBV parameters.

• HCV coinfection -- especially with detectable serum HCV RNA -- was independently associated with low-level or absent anti-HBs antibodies in HBsAg negative persons with anti-HBc.

• Absent or low-level anti-HBs was more common than detectable serum HBV DNA.

• Presence of HCV RNA was an independent factor predicting detectable HBV DNA.

• HIV infection was associated with an increased risk of low-level or absent anti-HBs, but this did not reach statistical significance.

• HIV infection did not independently predict presence of detectable HBV DNA.

"Our study revealed that occult HBV infection in anti-HBc positive/HBsAg negative patients defined as HBV DNA positivity in serum is most probable in HCV infected patients with low level or lack of anti-HBs antibodies," the investigators concluded.

08/14/07

References

T Perez-Rodriguez, B Sopena, A Ocampo, and others. Isolated antibodies to hepatitis B core antigen: clinical differences among HIV-positive and HIV-negative patients. 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention (IAS 2007). Sydney, Australia, July 22-25, 2007. Abstract MOPEB053.

J Kubicka, A Kamiska, E Burkacka-Firlag, and others. Anti-HBs and HBV DNA presence in anti-HBc-positive/HBsAg-negative subjects coinfected with HIV and HCV. IAS 2007. Abstract MOPEA082.