Infections in children with Juvenile Idiopathic Arthritis, more frequent than in healthy children? Prospective multi-center observational study.
Authors:   Hospital La Paz, Madrid, Madrid, España, Udaondo Gascón Clara , Núñez Cuadros1 Esmeralda ,   Hospital Regional Universitario de Málaga, Málaga, Málaga, España, Murias Loza Sara ,   Hospital La Paz, Madrid, Madrid, España, Remesal Camba Agustín ,   Hospital La Paz, Madrid, Madrid, España, Alcobendas Rueda Rosa ,   Hospital La Paz, Madrid, Madrid, España, Guerrero López Concepción ,   CS Tres Cantos, Madrid, Madrid, España, Guillén Martín Sara ,   Hospital de Getafe, Madrid, Madrid, España, Escuredo Bergua Marta ,   CS Parque Europa, Madrid, Madrid, España, Aleo Lujan Esther ,   Hospital Clínico San Carlos, Madrid, Madrid, España, Alonso Martín Daniel Enrique ,   CS Lucero, Madrid, Madrid, España, Tagarro García Alfredo ,   Hospital Infanta Sofía, Madrid, Madrid, España, De Santiago García-Caro Eloísa ,   CS Tiro de Pichón, Málaga, Málaga, España, Camacho Lovillo Marisol ,   Hospital Virgen del Rocío, Sevilla, Sevilla, España, Díaz Fernández Fátima ,   CS San Hilario, Sevilla, Sevilla, España, Arenas Cabrera Dolores ,   CS Cisneo Alto, Sevilla, Sevilla, España, Lirola Cruz María José ,   Instituto Hispalense de Sevilla, Sevilla, Sevilla, España, Camacho Conde Pilar ,   Grupo IHP, Centro Alcalá de Guadaira, Sevilla, Sevilla, España, Calvo Rey Cristina ,   Hospital La Paz, Madrid, Madrid, España
Published: June 2022

Abstract Background Children with JIA may have a higher risk of infection. Our objectives are to describe and compare infection rates in JIA patients vs non-JIA counterparts. Methods A prospective, multicenter observational study was performed in Spain from 01/2017 to 06/2019. JIA patients from 7 participating hospitals and children without JIA (siblings of JIA patients, and non-JIA children from primary health centers) were followed up with quarterly questionnaires recording infection episodes. Tuberculosis, Herpes Zoster, and infections requiring hospital admission were considered severe infections. Rate of infection (episodes/patient/year) was compared using a Generalized Estimating Equations Model. Results 371 children (181 JIA and 190 non-JIA) were included. Median age was 8.8years (IQR 5.5 – 11.3); 75% of JIA patients received immunosuppressive treatment (24% methotrexate, 22% biologic, 26% both). 667 infections were recorded, 15(2.2%) considered severe. Infection rate was 1.31 (95%CI 1.1 – 1.5) in JIA and 1.12 (95%CI 0.9 – 1.3) in non-JIA participants (p0.19). Age <4 years increased 2.5 times infection rate (2.51 vs. 0.98, p<0.001) in both groups. The most frequent infection sites were upper respiratory (62.6% vs. 74.5%) and gastrointestinal (18.8%vs 11.4%). There were no differences in severe infections (2.5%vs 2%, p0.65) among groups. In JIA children, younger age and higher disease activity (JADAS71) were associated with a higher infection rate. Conclusions Despite being a potential risk group, we found no differences in infection rate, severity, type and antibiotic treatment between patients with and without JIA. Most infections were mild. Age below 4 years increased infection risk in both groups. Higher disease activity was associated with a higher infection rate in JIA patients.