No impact of interleukin-28B polymorphisms on spontaneous or drug-induced hepatitis delta virus clearance

Background: rs12979860 and rs8099917 interleukin-28B polymorphisms are associated with spontaneous or interferon-alpha induced hepatitis C clearance, "CC" and "TT" genotypes (respectively) being the most favourable. There are no data on the influence of interleukin-28B polymorphisms on hepatitis delta clearance in hepatitis B/D co-infected patients. Aims: The present study explores the potential influence of both rs12979860 and rs8099917 polymorphisms on delta infection outcome. Methods: Retrospective-longitudinal study on 55 European patients observed for at least 4 years, selected from a cohort of 439 subjects positive for hepatitis delta antibodies and hepatitis B core antibodies. The rate of spontaneous and interferon induced delta-RNA clearance was compared in interleukin-28B rs12979860 "CC" vs "non CC", and in rs8099917 "TT" vs "non TT" genotypes. Results: Prevalence of rs12979860 C allele was 60%, consistent with the reported prevalence in Italy (67%, p = 0.128). No significant differences in spontaneous clearance rate were observed between rs12979860 "CC" and "non CC" genotypes (13.3% vs 7.5%, respectively, p = 0.60), and between rs8099917 "TT" and "non-TT" genotypes (11.1 vs 7.1%, respectively, p = 0.67). No differences were observed for interferon-induced delta-RNA clearance either. Conclusions: Our data suggest that interleukin-28B polymorphisms might not influence hepatitis delta clearance rate in either natural history or interferon-alpha response. Published by Elsevier Ltd on behalf of Editrice Gastroenterologica Italiana S.r.l.