Phase 3 baricitinib trials (2890 pts) there were 215 prior/occult HBV infection (HbcAb+) and 8 (3.7%) had a positive HBV DNA+ (≥29 IU/mL). Four met the definition of reactivation and 3 required antiviral therapy = check HBV serologies with JAK inhib use https://t.co/9xGIu5hzNh