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

Abstract 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 This is a single center, 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 and C-reactive protein (CRP) levels at 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. Results Almost all patients (n=29) but one in the HCQ group (14/15) relapsed during follow-up. However, HCQ treatment was associated with an increased median 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<0.001). There were no signficant differences in CRP levels at flare between groups (p=0.615). Conclusions In this prospective study, HCQ use was associated with a GC-sparing effect and an increased flare-free survival period in patients with colchicine resistant GC-dependent IRP. Funding Acknowledgement Type of funding source: None