303. LEUKOCYTE DYNAMICS BEFORE, DURING AND AFTER TREATMENT IN GIANT CELL ARTERITIS AND POLYMYALGIA RHEUMATIC PATIENTS. (29th March 2019) - Graver, Jacoba; van Sleen, Yannick; Abdullahad, Wayel; van der Geest, Kornelis; Boots, Annemieke; Sandovici, Maria; Brouwer, Elisabeth