Clinical

HIV-infected patients with isolated anti-HBc antigen may require HBV vaccine

Last Updated: 2005-05-10 16:24:48 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A substantial number of HIV-infected individuals who test positive for isolated antibody to hepatitis B core antigen (anti-HBc) do not have an anamnestic or rapid response to hepatitis B vaccine, according to a new study.

"This suggests that some of these subjects have not been previously exposed to hepatitis B virus, and that the positive test in these cases is a false positive result," lead investigator Dr. Rajesh T. Gandhi from Massachusetts General Hospital in Boston told Reuters Health.

"If confirmed in larger studies, this finding would suggest that HIV-positive subjects who test positive for isolated anti-HBc should receive hepatitis B vaccination," Dr. Gandhi said.

It is unclear, at present, whether HIV-infected patients who test positive for anti-HBc should be vaccinated with hepatitis B vaccine, Dr. Gandhi and colleagues note in the May 1st issue of The Journal of Infectious Diseases.

They assessed the anamnestic response rate in 69 HIV-infected subjects who tested negative for hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) and were immunized with hepatitis B vaccine.

Twenty-nine subjects (42%) tested positive for anti-HBc and 40 (58%) tested negative for anti-HBc.

According to the team, the overall rate of anamnestic response to hepatitis B vaccination was low (16%) and did not differ significantly between subjects who tested positive for anti-HBc (24%) and those who tested negative for anti-HBc (10%) before vaccination.

This suggests that testing for anti-HBc alone "may not be a reliable assessment of protection from HBV infection," they contend.

An "unexpected finding," according to the team, was that HIV/HCV-coinfected subjects were less likely to develop high anti-HBs titers after the third vaccination than were those injected with HIV alone.

Further study of the response to hepatitis B vaccination in larger groups of HIV/HCV-coinfected individuals is warranted, they conclude.

J Infect Dis 2005;191:1435-1441.