High rate of serious infection in juvenile idiopathic arthritis patients under biologic therapy in a real-life setting

Objectives: To assess the rate of serious and/or opportunistic infections in juvenile idiopathic arthritis (JIA) patients from a single tertiary center under biologic therapy and to identify possible risk factors associated to these complications. Methods: A total of 107 JIA patients followed at the biologic therapy center of our tertiary university hospital using a standardized electronic database protocol including demographic data, clinical and laboratorial findings and treatment at baseline and at the moment of infection. Opportunistic infections included tuberculosis, herpes zoster and systemic mycosis. Results: A total of 398 patient-yrs(py) were included. The median time of biologic exposure was 3.0 years (0.15-11.5). We observed 35 serious/opportunistic infectious events in 27 (25%) patients: 31(88.6%) were serious infections and four (11.4%) opportunistic infections. Serious/opportunistic infections rates were 10.6/100py for ETN, 10.9/100py for ADA, 2.6/100py for ABA and 14.8/100py for TCZ. Comparison of 27 patients with and 80 without infection showed a higher frequency of systemic-onset JIA, lower age at biologic therapy initiation and a history of previous serious infection (p