309. Real life experience of evaluation and treatment of large Vessel Vasculitis: A Single Centre Experience.

Background: Giant Cell Arteritis (GCA) is a large vessel vasculitis with overlapping phenotypes including classic cranial arteritis and large-vessel GCA (LV-GCA). Imaging studies of patients with GCA have demonstrated large-vessel involvement is present in up to 83% of patients1. LV-GCA increases the likelihood of aneurys and this is associated with significant mortality. Treatment includes corticosteroids and immunosuppressants such as Methotrexate or Tocilizumab. Methods: All patients were diagnosed by CT-angiogram or CT-PET from 2011 to 2020. Clinical, biochemical and radiographic data prior to and 6 months following therapy were analysed. Results: Of 24 patients, 12/24 patients were female. Median age was 64.5 years (IQR 60.8-72). Median time from sympto to diagnosis was 2 months (IQR 1-6.3). Of 24 patients analysed, 18 were diagnosed by CT-PET, 5 by CT angiogram and 1 on thoracic aorta biopsy. The clinical features included: refractory Polymyalgia Rheumatica (45.8%), weight loss (33.3%), chest pain (25%), abdominal pain (20.8%), BP difference >10mmHg (20.8%), fever (16.6%), limb claudication (12.5%), cranial GCA (8.33%), y cough (8.3%) and joint swelling (4.16%). The vessels involved in decreasing order were: Aorta (91.6%), Subclavians (54.16%), both carotids (33.33%), iliacs (29.16%), both axillaries (20.83%), both femorals (16.66%), mesenteric (12.5%), both vertebrals (8.33%) and popliteal (4.16%). 22/24 patients were given prednisolone. Prednisolone was not given in 2 patients for relative contraindications, multifocal motor neuropathy and possible cancer. 23/24 were given additional immunosuppresants including Methotrexate (n=10), Cyclophosphamide (n=7), Mycophenolate (n=3), Leflunomide (n=2) and Tocilizumab (n=1). 6/24 patients required a second agent for progressive or refractory disease. Two patients were given Tocilizumab, One patient Cyclophosphamide and three patients were given Rituximab. At 6 months, mean CRP fell from 108.6 to 4.97mg/L (p<0.001), ESR from 70.1 to 15mm/hr (p<0.001), Prednisolone dose from 43.9 to 15.7mg (p