OBJECTIVE: The course of hepatitis B virus (HBV) infection after kidney transplantation is aggressive, with a high mortality rate from liver disease mainly in patients who were serum hepatitis B e antigen (HBeAg) or HBV DNA-positive before transplantation. Lamivudine has been shown to be a potent inhibitor of HBV replication. The aim of the study was to examine the efficacy and safety of lamivudine therapy in patients with chronic renal failure and chronic HBV infection. METHODS: The study population consisted of six potential candidates for kidney or combined kidney and liver transplantation aged 25-49 yr (four patients had already undergone a kidney transplantation and developed chronic rejection). All were serum HBeAg and/or HBV DNA-positive and had been maintained on hemodialysis for 3 months to 3 yr. The duration of HBV infection was 7 months to 14 yr. Serum alanine aminotransferase (ALT) levels ranged from 72 to 610 U/L (median, 158 U/L). Liver histological evaluation showed mild to moderate chronic hepatitis (n = 4) or liver cirrhosis (n = 2). None of the patients was infected with hepatitis C or D viruses. In four patients, treatment consisted of 10 mg of oral lamivudine per day. In the other two patients, a virological and biochemical response could be achieved only when the dose was increased to 40 mg/day. RESULTS: Lamivudine treatment was associated with 1) normalization of serum ALT levels and rapid disappearance of serum HBV DNA (by hybridization) (five patients, one of whom died from sepsis); 2) seroconversion: Disappearance of HBeAg (three patients) and HBsAg (two patients); 3) minor side effects: Abdominal pain and nausea (one patient); 4) clinically asymptomatic lamivudine resistance 8 months after treatment (one patient); and 5) successful combined kidney and liver transplantation with no evidence of recurrent HBV infection at 6-8 months postoperatively (two patients with cirrhosis). CONCLUSIONS: Lamivudine therapy is effective as an HBV replication inhibitor in patients with chronic renal failure and HBV infection. Prospective studies of lamivudine pharmacokinetics and dosing in renal failure are needed to be able to treat patients appropriately. Although our study is small and further follow-up is needed, our data suggest that lamivudine therapy may enable selected patients with chronic hepatitis B to undergo kidney or combined kidney and liver transplantation in patients with established cirrhosis. (C) 2000 by Am. Coll. of Gastroenterology.