AUTHOR=Udaondo Clara , Núñez Cuadros Esmeralda , Murias Sara , Remesal Agustin , Alcobendas Rosa , Guerrero Concepción , Guillen-Martin Sara , Escuredo Marta , Aleo Esther , Alonso Daniel , Tagarro Alfredo , De Santiago Eloisa , Camacho-Lovillo Marisol , Diaz Fatima , Arenas Dolores , Camacho Pilar , Lirola Maria Jose , Díaz Almirón Mariana , Calvo Cristina TITLE=Are infections in children with juvenile idiopathic arthritis more frequent than in healthy children? A prospective multicenter observational study JOURNAL=Frontiers in Pediatrics VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.917731 DOI=10.3389/fped.2022.917731 ISSN=2296-2360 ABSTRACT=Background

Children with juvenile idiopathic arthritis (JIA) might be at a higher risk of infection. Our objectives are to describe and compare infection rates in patients with JIA vs. healthy patients.

Methods

A prospective, multicenter observational study was performed in Spain from January 2017 to June 2019. Patients with JIA from 7 participating hospitals and children without JIA (siblings of patients with JIA, and non-JIA children from primary health centers) were followed up with quarterly questionnaires to record infection episodes. Tuberculosis, herpes zoster, and infections requiring hospital admission were considered severe infections. Rates of infection (episodes/patient/year) were compared using a generalized estimating equations model.

Results

A total of 371 children (181 with and 190 without JIA) were included. The median age was 8.8 years (IQR 5.5–11.3); 75% of the patients with JIA received immunosuppressive treatment (24% methotrexate, 22% biologic, 26% both). A total of 667 infections were recorded; 15 (2.2%) were considered severe. The 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 (p = 0.19). Age <4 years increased the infection rate by 2.5 times (2.72 vs. 1.12, 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%, p = 0.65) between the groups. In children with JIA, younger age and higher disease activity (JADAS71) were associated with a higher infection rate.

Conclusion

We found no differences in the infection rate or infection severity between patients with and without JIA. Most infections were mild. An age younger than 4 years increased the infection risk in both groups. Higher disease activity was associated with a higher infection rate.