AB1367 PET ASSESSMENT OF THE EFFECTIVENESS OF TOCILIZUMAB IN GIANT CELL ARTERITIS. STUDY OF 101 PATIENTS FROM CLINICAL PRACTICE

Abstract

Background: Positron emission tomography (PET) is one of the tools available for the diagnosis of extracranial large-vessel vasculitis (1-5). Tocilizumab (TCZ) has shown efficacy in large-vessel vasculitis (LVV) including GCA. However, the improvement objectifed by imaging techniques after TCZ therapy in extracranial GCA patients is controversial. Objective(s): To assess the effectiveness of TCZ improving the wall vessel infam-mation by PET in GCA patients with large-vessel involvement. Method(s): Observational, multicenter study of 101 GCA patients treated with TCZ. GCA was diagnosed according to: a) ACR criteria, and/or b) biopsy of temporal artery, and/or c) presence of signs of vessel wall infammation by PET, defned by the presence of vascular wall uptake of Fluorodeoxyglucose (FDG). Patients were divided into two subgroups: a) with, and b) without signs of improvement (partial or total) in the follow-up PET. Result(s): We studied 101 patients (74 women/27 men; mean age 69.7+/-9.3 years). Main clinical features of GCA with and without PET improvement are shown in Table 1. The group of patients which experienced PET improvement was older and was receiving higher doses of corticosteroids at TCZ onset. Conclusion(s): TCZ seems to be effective controlling GCA including vascular involvement detected by PET. However, the improvement observed by PET is most often partial, and rarely complete.