AIM: To investigate the role of pegylated-interferon (IFN)α-2b in the management of patients with lamivudine-resistant chronic hepatitis B. METHODS: Twenty consecutive anti-HBe positive patients were treated with pegylated IFNα-2b (100μg sc once weekly) for 12 mo. There was no interruption in lamivudine therapy. Hematology, liver biochemistry, serum HBV DNA levels were detected by PCR, and vital signs were also assessed. Liver histology was assessed in some patients at entry and at wk 52 for comparison. RESULTS: Nine patients (45%) had a partial viro-logical end-treatment response; seven patients (35%) showed complete virological end-treatment response. Eight patients (40%) showed biochemical end-treatment response. There was a trend for higher virological response rates in patients who had previously responded to IFN and relapsed compared to IFN non-responders (four out of seven patients vs none out of six patients, respectively; P=0.1). Patients without virological end-treatment response showed significant worsening of fibrosis [median score 2 (range, 1 to 3) vs median score 3 (range, 1 to 4)], in the first and second biopsy respectively (P=0.014), whereas necroinflammatory activity was not significantly affected. Patients with complete or partial virological end-treatment response did not show any significant changes in histological findings, possibly due to the small number of patients with paired biopsies (n = 5). Nevertheless, after 12 mo of follow-up, only one patient (5%) showed sustained virological response and only 2 patients (10%) showed sustained biochemical response. Two patients (10%) discontinued pegylated IFN both after 6 mo of treatment due to flu-like symptoms. CONCLUSION: Pegylated IFNα-2b, when added to ongoing lamivudine therapy in patients with lamivudine-resistant chronic hepatitis B, induces sustained responses only in a small minority of cases. AIM: To investigate the role of pegylated-interferon (IFN) alpha-2b in the management of patients with lamivudine-resistant chronic hepatitis B. METHODS: Twenty consecutive anti-HBe positive patients were treated with pegylated IFNα-2b ) for 12 mo. There was no interruption in lamivudine therapy. Hematology, liver biochemistry, serum HBV DNA levels were detected by PCR, and vital signs were also assessed. Liver histology was assessed in some patients at entry and at wk 52 for comparison. RESULTS: Nine patients (45%) had a partial viro-logical end-treatment response; seven patients (35%) showed complete virological end-treatment response. Eight patients (40%) showed biochemical end-treatment response. for higher virological response rates in patients who had previously responded to IFN and relapsed compared to IFN non-responders (four out of seven patients vs none out of six patients, respectively; P = 0.1). Patients without virological end-treatment r The results of significant necening of fibrosis [median score 2 (range, 1 to 3) vs median score 3 (range, 1 to 4)], in the first and second biopsy respectively (P = 0.014), but necroinflammatory activity was not significantly affected Patients with complete or partial virological end-treatment response did not show any significant changes in histological findings, possibly due to the small number of patients with paired biopsies (n = 5). Nevertheless, after 12 mo of follow-up, only one Two patients (10%) showed sustained biochemical response and only 2 patients (10%) showed sustained biochemical response. Two patients (10%) discontinued pegylated IFN both after 6 months of treatment due to flu- like symptoms. CONCLUSION: Pegylated IFNα-2b , when added to ongoing lamivudine therapy in patients with lamivudine-resistant chronic hepatitis B, induces sustained responses only in a small minority of cases.