Hydroxychloroquine for colchicine-resistant glucocorticoid-dependent idiopathic recurrent pericarditis: A pilot observational prospective study

Background: Glucocorticoid (GC)-dependent, colchicine-resistant idiopathic recurrent pericarditis (IRP) remains a clinical challenge. We assessed for the first time the efficacy and safety of hydroxychloroquine (HCQ) in IRP. Methods and results: This is a post hoc analysis of prospectively collected data of 15 patients with refractory to standard therapy (colchicine plus either GC or anakinra) IRP (>= 3 recurrences, disease duration >= 12 months and inability to wean off treatment) treated with HCQ (400 mg/day). These patients were matched 1:1 for age, sex, and treatment type to IRP patients receiving standard-of-care treatment (control group, n= 15). Pericarditis recurrence, the time to 1st flare, the % of patients able to achieve a =50% reduction of baseline GC dose and the % reduction of GC dose, were compared between groups. HCQ did not reduce pericarditis recurrence risk as almost all patients (n= 29) but one in the HCQ group (14/15) relapsed during follow-up. However, HCQ treatment was associated with an increasedmedian time of flare-free survival (increase by 4 weeks compared to controls) and reduced hazard ratio for flare in survival analysis (HR= 0.36, 95% CI 0.16-0.77, p= 0.009). HCQ was also associated with a higher proportion of patients obtaining a >= 50% dose reduction of GCs (33.3% vs. 0% in the control group, p= 0.037) and reduced GC dose (HCQ:-43.5% vs. control:-4.5%, p b 0.001). No differences in CRP levels at flare was detected (p= 0.615). Conclusions: In this prospective study, HCQ depicted a GC-sparing effect and an increased flare-free survival period in patients with colchicine resistant GC-dependent IRP. (c) 2020 Elsevier B.V. All rights reserved.