Background An increased risk of herpes zoster among patients with juvenile idiopathic arthritis (JIA), especially with exposure to immunosuppressant medications and biologics have been described.
Objectives We determined incidence rates of herpes zoster and medication among children with JIA.
Methods Courses of treatments documented in the German Biologics Register (BiKeR) were analyzed to identify patients with herpes zoster and calculated crude infection rates (IR). Incidence ratio (IRR) was compared to published rates of 1.1/1000 person years(ref.). Demographics and exposure to corticosteroids, immunosuppressive drugs and biologics were analyzed.
Results The JIA cohort included 3,042 patients with 5,407 person-years of follow-up; 1,628 have used corticosteroids, 2,930 have used methotrexate, 299 azathioprine, 192 cyclosportine A, 1685 etanercept, 299 adalimumab and 48 tocilizumab. In total 18 herpes zoster events have been documented (6/1000 patients [3.2-8.7]; 3.3/1000 patient years [2.1-5.3]). Thus the incidence rate was higher than expected (p<0.001, IRR 2.97 [1.9-4.7]. In all patients the event resolved. One developed intercostal neuralgia. 1 had a recurrent herpes zoster. The occurrence of herpes zoster was significantly associated with the exposure to corticosteriods (100% of pts with zoster compared to 53% of who did not develop zoster; p<0.0001) and the duration of exposure to methotrexate (70±56 months vs. 36±33 months; p<0.01). There was no association to age or disease duration.
Compared to patients exposed to methotrexate, the exposure to any of the biologics etanercept, adalimumab or tocilizumab seemed not to further increase the risk of zoster, while exposure to azathioprine did (table).
Conclusions In JIA patients herpes zoster infection was found to be associated with treatment with corticosteroids and the duration of treatment with methotrexate. No association between treatment with biologics, etanercept, adalimumab or tocilizumab was found.
References Insinga RP, Itzler RF, Pellissier JM, Saddier P, Nikas AA. The incidence of herpes zoster in a United States administrative database. J Gen Intern Med. 2005 Aug;20(8):748-53.
Acknowledgements This study would not have been possible without the collaboration of numerous German and Austrian pediatric rheumatologists, patients and their parents.
The German Registry is supported by Abbott, Pfizer (Wyeth Pharma) and Roche, Germany
Disclosure of Interest G. Horneff Grant/research support from: Pfizer, Abbott, Roche, S. Nimmrich: None Declared