Interferon for treatment of breakthrough infection with hepatitis B virus mutants developing during long-term lamivudine therapy

Background:

We aimed to treat patients with chronic hepatitis B on long-term treatment with lamivudine who developed lamivudine-resistant hepatitis B virus (HBV) mutants along with clinical relapses. Methods: Of 217 patients with chronic hepatitis B who had been treated with lamivudine for 1–6 years, 23 (11%) developed lamivudine-resistant hepatitis B virus (HBV) mutants. Seven of them, including 1 whose case was previously reported, received interferon (IFN) daily for 4 weeks and then two or three times a week thereafter to cope with exacerbation of hepatitis. We investigated the efficacy of this IFN therapy in 6 patients, excluding the 1 previously reported. Results: In 4 patients, HBV DNA decreased to below the detectable limit of the branched DNA assay (<0.7 MEq/ml) accompanied by normalization of transaminase levels. During IFN therapy, 2 patients seroconverted to antibody to hepatitis B e antigen (HBeAg) and showed normalized transaminase levels. Interferon was required in 7 of the 111 (6%) patients with chronic hepatitis B who were positive for HBeAg, but in none of the 106 who were positive for antibody to HBeAg (P = 0.014). Conclusions: The efficacy of IFN in controlling virological breakthroughs and exacerbation of hepatitis by infection with lamivudine-resistant HBV mutants in patients with HBeAg-positive chronic hepatitis B could enhance the versatility of lamivudine, which may have to be given to them indefinitely.