Herpes Zoster Risk in Rheumatoid Arthritis Patients on Janus Kinase Inhibitors: A 17-Year Experience from Rheumatoid Arthritis Saudi Database (RASD)

Background/Purpose: The advent of targeted therapies, such as biologic disease-modifying anti-rheumatic drugs (bDMARDs) and Janus kinase inhibitors (JAKi), has revolutionized the treatment of rheumatoid arthritis (RA) patients who do not respond adequately to conventional disease-modifying anti-rheumatic drugs (csDMARDs). Concerns have been raised about the increased risk of infections, especially herpes zoster (HZ). The association between JAKi treatment and HZ remains complex. The objective of this study was to assess the risk of HZ among RA patients in our Rheumatoid Arthritis Saudi Database (RASD) receiving JAKi and other DMARDs. Patients and Methods: A 17-year retrospective multicenter chart review study was conducted in Saudi Arabia using RASD. We included patients diagnosed with RA according to the American College of Rheumatology criteria who were 18 years of age and above, on different modalities of treatment: csDMARDs, bDMARDs, targeted synthetic DMARDs (tsDMARDs) with or without concomitant GC. The following information was collected: demographics, comorbidities, medications, HZ occurrence, and vaccination history. Results: A total of 614 patients diagnosed with RA were enrolled in the study of whom 87.6% (n=538) were female and 98.2% (n = 603) were of Arab ethnicity with a mean age was 48.79 ± 13.35 years. Herpes zoster (HZ) occurred in only 1.1% (n = 7) of patients. JAKi therapy was not associated with an increased risk of HZ (p = 0.454). However, Asian ethnicity (p = 0.010) and cumulative GC exposure ≥60 mg (p = 0.035) were significantly associated with higher HZ risk. Conclusion: We did not detect any association between JAKi and HZ infection in our RASD. On the other hand, cumulative GC of 60 mg or more and Asian ethnicity were identified as significant risk factors. These findings provide a basis for future nationwide studies aimed to deliver personalized preventive strategies against HZ.