Pediatric Recurrent Pericarditis: Appropriateness of the Standard of Care and Response to IL-1 Blockade.

Objective: To analyze, in a cohort of pediatric patients with recurrent pericarditis undergoing anti-interleukin (IL)-1 treatment: the agent and dosing used as first-line treatment, the long-term efficacy of IL-1 blockers, the percentage of patients achieving a drug-free remission, and the presence of variables associated with drug-free remission.

Study Design: Data were collected from patients' charts. The annualized relapse rate (ARR) was used for evaluation of treatment efficacy, and bivariate logistic regression analysis was used for variables associated with drug-free remission.

Results: Fifty-eight patients, treated between 2008 and 2018, were included in the study (mean follow-up. 2.6 years). Of the 56 patients treated with first-line drugs, 14 not responsive patients were underdosed. Fifty-seven patients were treated with anakinra: the ARR before and during daily treatment was 3.05 and 0.28, respectively (P < .0001); an increase to 0.83 was observed after the reduction/withdrawal of treatment (P < .0001). The switch from anakinra to canakinumab (5 patients) was associated to an increase of the ARR (0.49 vs 1.46), but without statistical significance (P = .215). At last follow-up, only 9 of the 58 patients had withdrawn all treatments. With the limits of a retrospective study and the heterogeneity between the patients enrolled in the study, a shorter duration of treatment with anakinra was the only variable associated with drug-free remission.

Conclusions: This study shows that most pediatric patients with recurrent pericarditis needing IL-1 blockade received an inadequate treatment with first-line agents. The effectiveness of anakinra is supported by this study, but few patients achieved drug-free remission. The different rate of response to anakinra and canakinumab may suggest a possible role of IL-1α in the pathogenesis of recurrent pericarditis.