Trial Design Monocentric observational study, single arm, based on imaging of patients with active Large Vessel Giant Cell Arteritis (LV-GCA) , treated with Tocilizumab (TCZ) s.c. and with ultra-short glucocorticosteroids (GCs).~Duration of study per Subject 52 weeks of observation during standard of care (SOC) and 24 weeks of follow-up~Target Population Patients aged older than 50 years with active large vessel giant cell arteritis (LV-GCA) based on evidence of large vasculitis at imaging.~Patients with active disease will be enrolled according to the following inclusion criteria:~PET/CT showing vascular FDG uptake ≥2 in at least one vascular district and at least one among~ESR >40 mm/h or CRP >10 mg/l~Cranial or systemic symptoms of GCA or symptoms of polymyalgia rheumatica (PMR)~Primary Objectives~To evaluate the functional and morphological imaging (PET and MRA scores) variations at 24, 52 and 76 weeks compared to baseline values.~To evaluate the proportion of patients with relapse free remission (RFR) at week 24, 52 and 76.~To assess agreement between of MRA and PET scores and physician-determined disease activity status.~Secondary Objectives~To evaluate if patients have a reduced risk of aortic dilatation compared with an hystorical cohort of patients with LVV treated with GCs only and longitudinally followed at our rheumatology division.~immunological effects of steroid and TCZ at baseline, after 3 days, at week 24, 52 and 76
The objective of our study is to evaluate the functional and morphological imaging variations at 24 and 52 weeks compared to baseline during TCZ-treatment and 6 months after the suspension of TCZ. We will also evaluate the variations of aortic dilatation during the study period using the PET/CT in comparison with an hystorical cohort of patients with LVV treated with GCs only and longitudinally followed at our rheumatology division.