 Randomized, double blind study comparing the efficacy of pegylated interferon-alfa2a plus placebo versus pegylated interferon-alfa2a plus tenofovir for the treatment of chronic delta hepatitis. 70 Patients will be randomized 1:1 into the two groups. Treatment duration: 96 weeks. Follow-up: 24 weeks. Long-term-follow-up: until week 358. 