Rare clinically significant hepatic events and hepatitis B reactivation occur more frequently following rather than during direct-acting antiviral therapy for chronic hepatitis C: Data from a national US cohort.

Recently, cases of hepatitis B virus reactivation (HBVr) with direct-acting antiviral therapy (DAAs) for HCV have been reported. However, few data exist from large, Western cohorts. The study objectives were to evaluate the incidence of alanine aminotransferase (ALT) flares, clinically significant hepatic events, and HBVr among a national cohort of US veterans with prior exposure to HBV (anti-HBc+) treated with DAAs. We used a national administrative database to identify patients treated with DAAs from January 2014 through November 2016 and obtained clinical and demographic as well as HBV and HCV treatment data. HBVr was defined as an at least 1-log increase in HBV DNA titre. Among 17 779 anti-HBc+ patients, 17 400 were HIV- and 379 were HIV+. Among the HIV- patients, 17 266 (99%) were HBsAg- prior to DAA therapy and 134 were HBsAg+. Among HIV-, HBsAg- patients, ALT elevations greater than 10 times the upper limit of normal (ULN; ≥300 IU/mL) were rare and occurred more frequently after treatment completion: 31 cases (<0.1%) during vs 85 (0.6%) following treatment. Clinically significant hepatic events defined as ALT increases >100 IU/L with total bilirubin >2.5 mg/dL occurred in 39 cases (0.3%), most often following DAA completion (n = 35 cases, 3/35 in setting of HCV relapse). Among 31 patients with post-DAA hepatic events without HCV relapse, 10 (32%) were confirmed unrelated to HBVr by HBsAg and/or HBV DNA testing, 1 (3%) confirmed due to HBVr, and 20 (65%) did not have documented HBV-related testing. One additional case of HBsAg- to + seroreversion was identified. Among HBsAg+ DAA recipients, 2/97 (2%), both with cirrhosis, experienced ALT elevations ≥300 IU/mL in the setting of HBVr. In conclusion, clinically significant hepatic events and HBVr were rare and much more likely among HBsAg-positive individuals. Anti-HBc + patients should be monitored for ALT flares and HBVr during and possibly for up to 6 months post-DAA therapy.