Association Between Medications and Herpes Zoster in Japanese Patients with Rheumatoid Arthritis: A 5-year Prospective Cohort Study

Objective. To investigate the association between medications and herpes zoster (HZ) in patients with rheumatoid arthritis (RA) given biological disease-modifying antirheumatic drugs (bDMARD) or conventional synthetic DMARD in the clinical setting during 5 years using the Registry of Japanese Rheumatoid Arthritis Patients on Biologics for Longterm Safety (REAL) database. Methods. We calculated the crude incidence rate (IR) of HZ treated with systemic antiviral medications in 1987 patients from the REAL database. To estimate the association between HZ and medications, a nested case control study was performed with 1: 5 case-control pairs matched for age, sex, observation start year, and comorbidity (HZ case group, n = 43; control group, n = 214). We calculated OR and 95% CI of the use of bDMARD, methotrexate (MTX), and corticosteroids for the occurrence of HZ using a conditional logistic regression analysis. Results. The median patient age was 60.0 years, female proportion was 81.5%, and median disease duration was 6.0 years. The crude IR (95% CI) of HZ was 6.66 (4.92-8.83)/1000 person-years. The OR (95% CI) of medication use were 2.28 (1.09-4.76) for tumor necrosis factor inhibitor (TNFi) and 1.13 (1.03-1.23) for oral corticosteroids dosage (per 1 mg prednisolone increment), both of which were significantly elevated. The OR of non-TNFi and MTX usage were not elevated. Conclusion. TNFi use and higher corticosteroids dosage were significantly associated with HZ in Japanese patients with RA in the clinical setting.