Biotherapy in juvenile idiopathic arthritis Moroccan patients: a single-center experience

In this study, we aimed to evaluate the clinicobiological findings and the biotherapy treatment response of Moroccan patients with juvenile idiopathic arthritis (JIA), and compare our results with those of populations of the same or different ethnicity. This retrospective cross-sectional study included patients aged 1-14 years, diagnosed between 2003 and 2018 with JIA according to the International League of Associations for Rheumatology (ILAR) 2004 revised criteria, who received biologics and who followed up during the year 2018 in the day hospital of our single-center tertiary pediatric rheumatology unit. Among 59 patients, 53% had systemic JIA, 29% seronegative polyarticular JIA, 8% arthritis-related enthesitis, 5% seropositive polyarticular JIA, 3% oligoarthritis and 2% psoriatic arthritis. Tocilizumab was the most prescribed biologic (34 patients), followed by Etanercept (25 patients), Adalimumab (6 patients), Anakinra (3 patients) and biosimilar Infliximab (3 patients). Eleven patients switched biologics. Erythrocyte sedimentation rate, number of active joints and the Juvenile Arthritis Disease Activity Score 27 (JADAS 27) decreased significantly at month three for 56 patients. These results were maintained at the last visit for 31 patients, while there was a slight worsening in 15 of them and no assessment in 13 patients due to lack of data. At the end of the evaluation, 39% of the patients were exclusively on biotherapy, while 61% were still on other disease-modifying antirheumatic drugs (DMARDs). Twenty-eight patients developed lymphopenia, 4 patients had elevated transaminases, 4 patients developed moderate infection, and 2 patients developed macrophage activation syndrome. To the best of our knowledge, this is the first Moroccan study on biotherapy in JIA. Our study population was characterized by a male predominance, a high frequency of the systemic form and a low percentage of positive antinuclear antibodies. We have shown that in the era of biologics, only 67.4% patients are nearly disease-free at the end of the study with a real risk of side effects. Although effective, biotherapy must be closely monitored because of potentially severe side effects, especially with Tocilizumab use.