Comparative risk of infections among real-world users of biologics for juvenile idiopathic arthritis: data from the German BIKER registry

To examine whether treatment with interleukin (IL)-1-, IL-6-, tumour necrosis factor α (TNFα)-inhibitors or Abatacept is associated with an increased risk of common infections, infections requiring hospitalization (SAE) or opportunistic infections among real-world juvenile idiopathic arthritis (JIA) patients. Furthermore, the influence of other patient-related covariates on the occurrence of infections was investigated. Patients diagnosed with JIA and treated with biologics were selected from the German BIKER registry. Incidence rates (IR) of infections per 100 person years were calculated and compared between the different cohorts. Using multivariate logistic regression, odds ratios with 95% confidence intervals (CI) were determined for the influence of patient-related covariates (age, diagnosis, laboratory data, concomitant medication, JIA activity, comorbidities, and premedication) on the occurrence of infections. 3258 patients entered the analysis. A total of 3654 treatment episodes were distributed among TNFα- (Etanercept, Adalimumab, Golimumab, Infliximab, n = 3044), IL-1- (Anakinra, Canakinumab, n = 105), IL-6- (Tocilizumab, n = 400) and T-cell activation inhibitors (Abatacept, n = 105). 813 (22.2%) patients had at least one infection, 103 (2.8%) patients suffered from an SAE infection. Both common and SAE infections were significantly more frequent in IL-1 (IR 17.3, 95% CI 12.5/24 and IR 4.3, 95% CI 2.3/8.3) and IL-6 cohort (IR 16.7, 95% CI 13.9/20 and IR 2.8, 95% CI 1.8/4.4) compared to TNFα-inhibitor cohort (IR 8.7, 95% CI 8.1/9.4 and IR 1, 95% CI 0.8/1.3). When comparing the influencing factors for various infectious diseases, the use of corticosteroids, younger age, cardiac comorbidities and higher JIA-activity are the most striking risk factors. Relative to TNFα inhibitors and Abatacept, IL-1 and IL-6 inhibitors were associated with an increased risk of common and SAE infections. The influencing covariates identified may be helpful for the choice of a suitable biologic to treat JIA.