Disease Characteristics and Change in Arthritis Activity according to Treatment in Hepatitis B Surface Antigen-positive Rheumatoid Arthritis Patients: a Retrospective Chart Review Study

BACKGROUND: Rheumatoid arthritis (RA) treatment may differ according to hepatitis B state and consequently may bring about different arthritis outcomes. However, whether hepatitis B affects treatment outcome remains unclear. We investigated differences in change in arthritis activity between RA patients according to concomitant hepatitis B virus infection. METHODS: A retrospective medical chart review was performed by two rheumatologic fellows using single center data, from January 2000 to March 2015. Among RA patients older than 18 years, patients with comorbidities that could affect RA treatment aside from hepatitis B were excluded. Using 1:3 propensity score matching, 40 hepatitis B virus surface antigen (HBsAg)-positive patients and 112 HBsAg-negative patients were included in the study. Data were collected longitudinally using standardized electronic forms. The longitudinal relationship between HBsAg-positivity and RA activity was analyzed using generalized estimating equations. RESULTS: RA activity showed time-dependent improvement. Reductions of swollen joint count over time were significantly larger in the HBsAg-negative group. However, changes in disease activity score in 28 joints with three variables (DAS28-3), tender joint count, erythrocyte sedimentation rate and C-reactive protein level did not differ between the groups. There were no differences in alanine aminotransferase level. HBsAg-positive patients were less likely to receive methotrexate (odds ratio [OR], 0.09; 95% confidence interval [CI], 0.04–0.19; P < 0.001) and more likely to receive sulfasalazine (OR, 3.67; 95% CI, 1.94–6.95; P < 0.001). CONCLUSION: RA medication use varied according to HBsAg-positivity. However, improvement in RA activity was not significantly affected by concomitant hepatitis B infection.