Polymyalgia Rheumatica (PMR) is treated with corticosteroids; however, long-term treatment is not feasible due to side effects. Withdrawal of corticosteroids causes a subset of patients to relapse, and there is no current way to understand what underlies this. Our research team has preliminary data from a small clinical study that indicates that different immune effector dynamics during the tapering of steroids correlate with relapse. This was achieved using the DNA methylation-specific immune cell profiling methods that Dr. Christensen has pioneered. What is proposed is a larger prospective study of 50 PMR patients to validate differences in CD4 and CD8 memory cells as a predictor of relapse. Finally, we also focus on the Glucocorticoid Methylation Index (GCMI), which is a collection of 28 CpG islands that are methylated in response to corticosteroids. This will allow our team to determine the predictive power of the GCMI for PMR.