RESUMO
AIM: To investigate the responses of TT virus (TTV) and hepatitis B virus (HBV) to a long-term lamivudine therapy. METHODS: Sixteen patients infected with both TTV and HBV were treated with lamivudine 100 mg daily for 30 months. Blood samples were drawn at the beginning of the therapy and subsequently at month 3, 6, 9, 12 and 30. Serum TTV was quantified by real time PCR and serum HBV was detected by hybridization assay and nested polymerase chain reaction. RESULTS: TTV infection was detected in 100 % of HBV-infected patients. Loss of serum TTV DNA after one year of treatment occurred in 1/16 (6 %) patients. At the end of therapy, TTV DNA was positive in 94 % of them. The decline of HBV viremia was evident at 3 months after therapy and the response rate was 31 %, 44 %, 63 %, 50 % and 50 % at month 3, 6, 9, 12 and 30, respectively. CONCLUSION: TTV replication is not sensitive to lamivudine and is highly prevalent in HBV-infected patients.