Flares after hydroxychloroquine reduction or discontinuation: results from the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort.

Abstract

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadObjectives: To evaluate systemic lupus erythematosus (SLE) flares following hydroxychloroquine (HCQ) reduction or discontinuation versus HCQ maintenance. Methods: We analysed prospective data from the Systemic Lupus International Collaborating Clinics (SLICC) cohort, enrolled from 33 sites within 15 months of SLE diagnosis and followed annually (1999-2019). We evaluated person-time contributed while on the initial HCQ dose ('maintenance'), comparing this with person-time contributed after a first dose reduction, and after a first HCQ discontinuation. We estimated time to first flare, defined as either subsequent need for therapy augmentation, increase of ≥4 points in the SLE Disease Activity Index-2000, or hospitalisation for SLE. We estimated adjusted HRs (aHRs) with 95% CIs associated with reducing/discontinuing HCQ (vs maintenance). We also conducted separate multivariable hazard regressions in each HCQ subcohort to identify factors associated with flare. Results: We studied 1460 (90% female) patients initiating HCQ. aHRs for first SLE flare were 1.20 (95% CI 1.04 to 1.38) and 1.56 (95% CI 1.31 to 1.86) for the HCQ reduction and discontinuation groups, respectively, versus HCQ maintenance. Patients with low educational level were at particular risk of flaring after HCQ discontinuation (aHR 1.43, 95% CI 1.09 to 1.87). Prednisone use at time-zero was associated with over 1.5-fold increase in flare risk in all HCQ subcohorts. Conclusions: SLE flare risk was higher after HCQ taper/discontinuation versus HCQ maintenance. Decisions to maintain, reduce or stop HCQ may affect specific subgroups differently, including those on prednisone and/or with low education. Further study of special groups (eg, seniors) may be helpful. Keywords: autoimmune diseases; epidemiology; hydroxychloroquine; systemic lupus erythematosus.Canadian Institutes of Health Research (CIHR) Fonds de Recherche du Quebec Sante (FRQS) Research Institute of the McGill University Health Centre (RI-MUHC) Canadian Institutes of Health Research (CIHR) Singer Family Fund for Lupus Research Arthritis Society Chair in Rheumatic Diseases at the University of Calgary Lupus UK West Birmingham Hospitals NHS Trust National Institute for Health Research (NIHR)/Wellcome Trust Birmingham Clinical Research Facility tier 1 Canada Research Chair on Systemic Autoimmune Rheumatic Diseases Bio & Medical Technology Development Programme of the National Research Foundation of the Republic of Korea United States Department of Health & Human Services National Institutes of Health (NIH) - US