Conference Coverage

Eosinophilia Common During IL-1, IL-6 Use in Patients With sJIA, non-sJIA

According to a recent study, eosinophilia is common in patients with juvenile idiopathic arthritis (JIA) who use interleukin 1 (IL-1) and interleukin 6 (IL-6) inhibitors and may be associated with pre-treatment macrophage activation syndrome (MAS) in patient with systemic juvenile idiopathic arthritis (sJIA). The results of the study were presented at the American College of Rheumatology Convergence 2022 in Philadelphia, PA.1

“Children with systemic sJIA exposed to IL-1 and IL-6 inhibitors may develop eosinophilia with an atypical rash, reportedly in association with HLA-DRB1*15:XX,” the authors wrote.

Indeed, the authors expressed concern that these features, which are similar to a drug reaction, may drive MAS and sJIA-lung disease.

In their study, the authors reviewed patients with JIA who used IL-1 and IL-6 inhibitors, comparing the time exposed to them to the time on tumor necrosis factor inhibitors or other biologics and methotrexate. Changes in treatment and activity were noted within 10 weeks of a patient developing eosinophilia.

The authors examined two cohorts: patients with sJIA (n = 67), and patients with non-systemic JIA (n = 36). After a median follow up of 70 months, the researchers observed that eosinophilia was common during IL-1 and IL-6 inhibitor use for both cohorts. For patients with sJIA using IL-1 and IL-6 inhibitors, the researchers found that the only significant predictor of eosinophilia was MAS prior to being treated with a biologic.

Additionally, two patients developed severely progressive lung disease, neither had preceding eosinophilia, and lung disease preceded Il-1 and IL-6 inhibitor use in one patient.

“Additional risk factors for sJIA-lung disease remain to be defined, as eosinophilia and DRB1*15:XX alleles were neither necessary nor sufficient for LD in our sJIA patients,” the researchers concluded.


—Jessica Ganga


  1. Wobma H, Taylor M, Lam KP, et al. Incidence, risk factors, and outcomes of eosinophilia on IL-1 and IL-6 inhibitors in systemic and non-systemic juvenile idiopathic arthritis. Paper presented at: American College of Rheumatology Convergence 2022; November 10-14, 2022; Philadelphia, PA. Accessed November 18, 2022.