What are the characteristics of paradoxical effects in the Biotherapies Registry of the Moroccan Society of Rheumatology?

IntroductionThe main objective of our study was to assess the prevalence of paradoxical reactions in patients with chronic inflammatory rheumatism treated with biologic drugs, while secondary objectives were to determine the type of paradoxical reactions and to investigate associated factors.Material and methodsWe conducted a descriptive cohort study using 36-month frozen data from the RBSMR registry. This is a registry promoted by the Moroccan Society of Rheumatology, including patients treated for rheumatoid arthritis (RA) or spondyloarthritis treated with a biologic drug. The paradoxical reaction was defined by the appearance of a pathology that could be treated by bio­logical drugs. We investigated the prevalence of paradoxical reactions, and the factors associated with their occurrence. Statistical analysis was performed using JAMOVI software.ResultsWe analyzed 440 patients in the RBSMR. Paradoxical reactions were found in 19 pa- tients (4.6%). The mean time to onset of paradoxical manifestations was 30 weeks (1–144 weeks). Uveitis was the most frequent paradoxical reaction, found in 9 patients, followed by psoriasis in 7 patients, and then pyoderma gangrenosum, lichen, and granulomatous dermatitis in only 1 patient each. These paradoxical effects were found predominantly in men (57.9% of cases). Etanercept was the most prescribed biologic, in 52.6% of patients with paradoxical reactions, followed by adalimumab in 21.1%, golimumab in 15.8%, and secukinumab in 5.3%. Permanent discontinuation of biological treatment was recommended for all patients. In univariate analysis, the occurrence of a paradoxical effect was related to sex (<i>p</i> = 0.05) and to disease activity in patients with RA (<i>p</i> = 0.04).ConclusionsOur study suggests that there is a low prevalence of paradoxical effects in our population. However, these are reactions that need to be identified and investigated to improve the mana­gement of our patients with chronic inflammatory rheumatism.