Paediatric recurrent pericarditis: Appropriateness of the standard of care and response to IL1-blockade

Objective: To analyse, in a cohort of paediatric patients with recurrent pericarditis (RP) undergoing anti-IL-1 treatment: the agent and dosing used as first line treatment, the long-term efficacy of IL1-blockers, the percentage of patients achieving a drug-free remission, the presence of variables associated with drug-free remission. Study design: Data were collected from patients' charts. Annualized relapse rate (ARR) was used for evaluation of treatment efficacy, bivariate logistic regression analysis for variables associated with drug-free remisison. Results: 58 patients, treated between 2008 and 2018, were included in the study (mean follow-up 2.6 years). 14/56 patients non-responsive to first line drugs were under-dosed. 57 patients were treated with anakinra: the ARR before and during daily treatment was 3.05 and 0.28, respectively (p<0.0001); 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=0.215). At last follow-up only 9/58 patients had withdrawn all treatments.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. Conclusion: This study shows that most of the pediatric patients with RP 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 IL1α in the pathogenesis of RP.