Clinical

Lamivudine resistance common in patients coinfected with hepatitis B and HIV

Last Updated: 2006-05-17 16:05:13 -0400 (Reuters Health)

By Will Boggs, MD

NEW YORK (Reuters Health) - Lamivudine resistance mutations are common in patients coinfected with HIV and hepatitis B virus (HBV), according to a report in the April 4th issue of AIDS.

The main findings include "the almost universal occurrence of lamivudine resistance over time in patients with HBV viremia and the unknown significance of the development of multiple mutations at sites within the HBV genome, including those that result in virus with the characteristics of vaccine escape mutants in vitro," Dr. Gail V. Matthews from the National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales, Sydney, told Reuters Health.

Dr. Matthews and colleagues investigated the prevalence and pattern of HBV mutations in a large population of HIV-HBV coinfected patients receiving long-term lamivudine therapy.

About two-thirds of the patients had HBV viremia, the authors report. HBV viremia was associated with a lower CD4 cell count nadir, higher HIV RNA at the time of resistance testing, higher alanine aminotransferase levels, and detectable HBeAg.

HBV polymerase mutations conferring lamivudine resistance were present in three quarters of the patients with HBV viremia, the results indicate. Such mutations increased in prevalence with increasing duration of treatment, reaching 94% of patients treated for more than 4 years.

Mutations in the HBV envelope gene and in the BCP/pre-core region were also common, the researchers note.

"As coinfected persons have an increased incidence of the triple mutant and as lamivudine monotherapy can lead to cross-resistance of other anti-HBV drugs, it is crucial to use anti-HBV therapy that reduces the HBV DNA rapidly and minimizes the development of HBV resistance," the authors conclude.

"In patients with HIV and HBV coinfection who require treatment for both viruses, I would recommend a combination of either lamivudine and tenofovir or emtricitabine and tenofovir within a fully active HAART regimen," Dr. Matthews said. "In patients who require treatment for HBV but not HIV, I would recommend either pegylated-interferon or entecavir alone."

AIDS 2006;20:863-870.