BACKGROUND: Tenofovir therapy has been found to be efficient in treating hepatitis B virus (HBV) in nontransplant patients. However, in the setting of solid-organ transplantation, the efficacy of tenofovir has not been tested. The aim of this pilot study was to assess the clinical and biologic response and tolerance to tenofovir therapy in HBV-positive organ transplant recipients.
METHODS: Seven patients, three kidney, three liver, and one cardiac transplant recipients, with chronic HBV infection were partial responders to adefovir (n=7), lamivudine (n=7), or entecavir (n=5) therapy. Consequently, they were placed on tenofovir therapy (245 mg daily, which was adapted to renal function) alone (n=4) or in combination with lamivudine (n=3). Tenofovir therapy was assessed at 1, 3, 6, and 12 months postinitiation or at the last follow-up.
RESULTS: HBV DNA viral load (4.16 [2.03-5.56] log10 copies/mL at baseline) became significantly decreased to 3.15 (1.08-5.17), 2.88 (1.3-4.3), 3.53 (1.3-5.75), 3.33 (1.3-7.57), and 2.31 (1.3-4.81) log copies/mL at 1, 3, 6, and 12 months posttenofovir initiation and at last follow-up, respectively (P=0.02). Three patients were HBV DNA negative at the last follow-up. Liver enzyme levels did not change significantly throughout the follow-up period. Clinical and biologic tolerance was excellent.
CONCLUSIONS: Even though HBV DNA clearance was not achieved in all patients, the results of this pilot study are encouraging and demonstrate that tenofovir therapy is safe and efficacious in treating HBV-positive organ transplant patients. However, a larger trial is needed to confirm these preliminary results.