Risk of serious bacterial infection associated with tumour necrosis factor-alpha inhibitors in children with juvenile idiopathic arthritis.

Objectives: TNF-α inhibitors (TNFIs) have a black box warning for increased risk of serious infection that was based on evidence from studies of adults. Evidence of the association is lacking for children. We aimed to examine the risk of infection posed by TNFIs compared with DMARDs in children with JIA.

Methods: We conducted a cohort study using the 2009-13 Truven MarketScan Commercial Claims and Encounters database. Children <16 years old with JIA who initiated monotherapy with TNFIs or DMARDs were identified and followed for occurrence of serious bacterial infection requiring hospitalization. Cox proportional hazard models were used to estimate hazard ratios for infection associated with TNFIs compared with DMARDs, adjusting for potential confounders with high-dimensional propensity scores and time-varying CS use.

Results: We identified 2013 DMARD initiators and 482 TNFI initiators with a mean follow-up of 255 and 307 days, respectively. We identified 18 and 11 patients with a serious infection in the DMARD and TNFI groups, resulting in crude rates of 1.28 (95% CI 0.76-2.02) and 2.72 (95%CI 1.36-4.86) per 100 person-years, respectively. In adjusted models, TNFIs were associated with an increased risk of serious bacterial infection compared with DMARDs (adjusted hazard ratio 2.72, 95% CI: 1.08, 6.86).

Conclusion: Use of TNFIs poses a higher risk of serious infection compared with DMARDs in children with JIA. Our analysis confirms the US Food and Drug Administration warning about TNFI-associated infection in children with JIA.