AB0702 THE INCIDENCE OF LARGE VESSEL VASCULITIS IN NORFOLK, UK

Abstract

BackgroundThere are no data on the collective incidence of the large vessel vasculitides. The data of incidence of GCA and Takayasu arteritis in the UK has been based on clinical coding in routine administrative datasets. There are no data on the incidence of these diseases based on clinically verified diagnoses. We studied the incidence of the large vessel vasculitides in a stable population with a predominant Northern European ancestry.ObjectivesTo report the incidence of large vessel vasculitis and its subsets in Norfolk, UK.MethodsIndividuals attending a secondary care hospital with a clinically verified diagnosis of primary systemic vasculitis made between 2011-2020, who lived within the NR postcode districts of Norfolk County borders were included if they met classification criteria (ACR 1990 or ACR/EULAR 2022) for GCA/ Takayasu arteritis[1-4], or had definite tissue or imaging evidence of large vessel vasculitis. The population data from the 2011 census, available from the office of national statistics was used as the denominator. If classification criteria for both GCA and TAK were met, a clinical decision was taken to decide on the subtype.Results272 individuals were diagnosed with a large vessel vasculitis in a population of 454,316 above the age of 18. The annual incidence of large vessel vasculitis in Norfolk is 59.9/million in population above the age of 18. The annual incidence of giant cell arteritis is 9.9/100000 in population above the age of 50 using the ACR 1990 criteria and 10.6/100000 using the ACR/EULAR 2022 criteria. There is a marked rise in the incidence from 2017 onwards when a fast-track pathway was formally established (Table 1). There is dip in the incidence in 2020 when services were suspended during the SARS-COV2 pandemic. The annual incidence peaks at 168.5/100000 in the 9thdecade of life and is commoner in females (12.3/100000) than males (7.3/100000). The annual incidence of Takayasu arteritis is 3.3/million in population above the age of 18 using the ACR 1990 criteria and 1.1/million using the ACR/EULAR 2022 criteria.ConclusionThis is the first study that reports the incidence of all objectively diagnosed large vessel vasculitis from a secondary centre which provides services to a large stable population in the East of England. The incidence of GCA rose with the establishment of a fast-track pathway and its peak may have been affected by the SARS-COV2 pandemic. GCA is commoner in females and peaks in the 8th and 9th decades.