Hepatitis B surface antibody titres and hepatitis B reactivation with direct-acting antiviral therapy for hepatitis C.

HBV reactivation can occur while undergoing direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV). The role of hepatitis B surface antibody (HBsAb) has not been systematically explored. Therefore, the purpose of this systematic review was to explore the role of the presence of HBsAb on the risk of HBV reactivation related to DAA therapy. We reviewed MEDLINE, CINAHL, EMBASE and Cochrane Central for studies on DAA therapy and data on HBsAb in patients with resolved hepatitis B (hepatitis B surface antigen-negative and hepatitis B core antibody-positive). We identified twenty-nine reports: thirteen case reports with HBV reactivation (10 HBsAb-negative and 3 HBsAb-positive patients) and sixteen cohort studies totalling 2528 patients with resolved HBV infection (1429 HBsAb negative, 1099 HBsAb positive). Reactivation was found in 12 (0.8%) HBsAb-negative and 7 (0.6%) HBsAb-positive individuals of cohort studies. All but two HBV reactivation occurred in patients with HBsAb titre <30 iU/L. The presence of HBsAb showed a trend towards delayed reactivation (median 12 weeks vs 9.5 weeks; P = .07). Importantly, with the exception of a patient with escape variant and an HIV-infected individual, no HBsAb-positive individual demonstrated clinical reactivation. HBsAb presence seems to protect from clinical HBV reactivation related to DAA therapy. The most pronounced prevention for reactivation may require titres greater than 30 iU/L.