FRI0200 TIME TO FLARE IN GIANT CELL ARTERITIS AND POLYMYALGIA RHEUMATICA AND REVIEW OF THE LITERATURE

Abstract

Background:Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two closely related inflammatory rheumatic diseases of the elderly. While glucocorticoid treatment leads to a dramatic initial improvement, the course of the diseases remains unpredictable and multifarious. Flare and relapses are common, however, data on this is limited[1][2].Objectives:We set out to evaluate the flare rate, time to first flare and steroid dose during flare of patients diagnosed with GCA and PMR in our practice. The aim was to identify optimal timing for clinical review and contribute towards best practice.Methods:A total of 218 patients diagnosed with GCA (38) and PMR (180) seen between 2015 and 2020 were audited. Demographic data was collected. Relapse rate, time to initial flare and steroid dose during flares were the primary endpoints for our analysis. Steroid sparing agent use was also documented.Results:Our cohort comprised of 38 GCA patients (M=15; F=23) and 180 PMR patients (M=71; F=99) who were diagnosed between January 2015 and January 2020.The mean age of diagnosis for patients with GCA and PMR was 73 years and 71 years respectively. 10 patients (4.6%) with PMR later progressed to develop Rheumatoid Arthritis and hence, were excluded from subsequent analyses. Most patients received an initial treatment of corticosteroid therapy for both diseases with a mean dose of 39.74mg for GCA and 18.23mg for PMR. During a mean follow up time of 13.8 months, 75 patients (36%) (GCA= 6; PMR =69) experienced at least one flare which was determined by clinical diagnosis either by unremitting reversion of initial symptoms and/or elevated inflammatory markers. While 13 patients (6%) (GCA = 2; PMR =11) had a flare following completion of initial steroid therapy, 62 patients (30%) (GCA = 4; PMR = 58) experienced flares during steroid tapering, the mean steroid dose observed during disease flare for the latter was 5.25 mg for GCA and 4.67 for PMR. Majority of relapses/flares for PMR patients occurred within the first year of diagnosis (mean = 8.38 months) and after the first year of diagnosis in GCA patients (mean = 15 months). Methotrexate was the most common traditional DMARD trialed as a steroid sparing alternative (GCA = 4; PMR =23) mostly introduced post flare/relapse. The mean appointment intervals for flares/relapses in our cohort was noticed to be during the 5thand 6thscheduled clinical review for GCA and between the 3rdand 4thclinical review for PMR patients.Conclusion:A flaring and relapsing course is common to both GCA and PMR especially during steroid dose tapering. Increased clinical surveillance and more gradual steroid tapering, particularly at the time when most flares/relapses are observed may help improve clinical outcomes and reduce glucocorticoid requirements in patients.