Adverse events of biological agents in pediatric rheumatologic diseases

Objectives To evaluate adverse events (AEs) in pediatric patients with rheumatologic diseases being treated with approved or off-label biologic agents (BAs). Methods This observational, retrospective, multicenter study was conducted from 2010 to 2022 in patients under 18 years of age with rheumatic diseases who were receiving interleukin-1 antibodies (Anti-IL1), interleukin-6 antibodies (Anti-IL6), and tumor necrosis factor alpha inhibitors (anti-TNF). Efficacy, AEs, and timing of AEs were collected from electronic medical records. Results Three hundred and fifteen BAs were prescribed to 237 patients. Fifty AEs occurred in 44 patients (18.6%). Anti-TNF exposure was present in 8 (72.2%) of 11 patients with latent tuberculosis (TB) and in all 7 patients with herpes infections. Four of 6 patients (66.7%) with recurrent upper respiratory tract infections and 7 of 8 patients (87.5%) with local skin reactions were on Anti-IL1. The cutoff value for latent TB development was determined as 23.5 months by ROC analysis (AUC: 0.684 ± 0.072, p = 0.038, 95% CI: 0.54-0.82). In patients who used BA for 23.5 months or more, the risk of latent TB was 5.94-fold ( p = 0.024, 95% CI: 1.26-27.97). Drug rash with eosinophilia and systemic symptoms (DRESS) occurred in 2 patients on anakinra, and anaphylaxis occurred in 1 patient on anti-IL6. There were no cases of malignancy or death in any patient. Conclusion The physician should be vigilant for latent TB in patients exposed to BA for more than 2 years. While local skin reactions are more prevalent in patients receiving anti-IL1, severe skin reactions such as DRESS may also occur.