PT - JOURNAL ARTICLE AU - Ming-Hui Hung AU - Ya-Chih Tien AU - Ying-Ming Chiu TI - Risk factors associated with loss of hepatitis B virus surface antibody in patients with HBV surface-antigen negative/surface antibody positive serostatus receiving biologic DMARDs to treat rheumatic diseases – a nested case-control study AID - 10.1101/661850 DP - 2019 Jan 01 TA - bioRxiv PG - 661850 4099 - http://biorxiv.org/content/early/2019/06/05/661850.short 4100 - http://biorxiv.org/content/early/2019/06/05/661850.full AB - Objectives To elucidate risk factors for loss of hepatitis B virus (HBV) surface antibody (anti-HBs) in patients with rheumatic diseases and HBV surface-antigen negative/anti-HBs positive (HBsAg−/anti-HBs+) serostatus during biologic disease-modifying anti-rheumatic drug (DMARD) treatment.Methods This nested case-control study prospectively enrolled patients with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis/psoriasis, and juvenile idiopathic arthritis, who were treated with biologic DMARDs from January 2013 to September 2017. The analytic sample included patients with HBsAg−/anti-HBs+ serostatus. Anti-HBs titers were monitored, and cases defined as anti-HBs <10 mIU/mL during follow-up. Cases were matched one-to-all with controls with anti-HBs ≥10 mIU/mL on the same event date and equivalent durations of biologic DMARDs treatment. Between-group characteristics were compared and risk factors for anti-HBs loss elucidated by conditional logistic regression analyses.Results Among 189 enrolled patients, 15 cases were matched with 211 controls. Risk factors associated with anti-HBs loss in multivariate analysis were low baseline anti-HBs titer (adjusted risk ratio = 0.96, 95% CI 0.93–0.99) and chronic kidney disease (adjusted risk ratio = 26.25, 95% CI 1.85–372.35). All cases had baseline anti-HBs titer <100 mIU/mL, and none developed HBV reactivation upon losing anti-HBs.Conclusions In addition to low baseline anti-HBs titer, chronic kidney disease is also an independent risk factors associated with loss of anti-HBs in patients with HBsAg−/anti-HBs+ serostatus who receive biologic DMARDs to treat rheumatic diseases.Significance Given that loss of anti-HBs precedes HBV reactivation and that the use of biologic DMARDs is increasingly widespread nowadays, understanding those who are at risk of loss of anti-HBs is an important and practical clinical issue.Innovation In addition to low baseline anti-HBs titer, chronic kidney disease is also an independent risk factors associated with loss of anti-HBs in patients with HBsAg−/anti-HBs+ serostatus who receive biologic DMARDs to treat rheumatic diseases.