OA33 The incidence of large vessel vasculitis in Norfolk

• Published in: Rheumatology (Oxford, England) Vol. 62; no. Supplement_2
• Main Authors: Mukhtyar, Chetan B, Beadsmoore, Clare, Coath, Fiona, Ducker, Georgina, Sisson, Katherine, Watts, Richard A
• Format: Journal Article
• Language: English
• Published: Oxford University Press 24.04.2023
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/kead104.033

Abstract Background/Aims There are no data on the collective incidence of the large vessel vasculitides. The 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 verfied diagnoses. We studied the incidence of the large vessel vasculitides in a stable population with a predominant Northern European ancestry. Methods Individuals 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 were included if they met classification criteria for GCA or Takayasu arteritis, or had definite tissue or imaging evidence of large vessel vasculitis. Population above the age of 18 as in the 2011 census, available from the office of national statistics, was accepted as the denominator. If classification criteria for both GCA and TAK were met, physician judgement was accepted as final diagnosis. Results 272 adults were diagnosed with large vessel vasculitis out of a population of 454,316. The annual incidence of large vessel vasculitis in Norfolk is 59.9/million in the adult population. The annual incidence of GCA is 9.9/100,000 over the age of 50 using the ACR 1990 criteria and 10.6/100,000 using the ACR/EULAR 2022 criteria. The rise in the incidence from 2017 onwards coincides with the establishment of a fast-track pathway (Table 1). The dip in the incidence in 2020 coincides with suspension of services during the SARS-CoV-2 pandemic. The annual incidence peaks at 168.5/100,000 in the 9th decade and is commoner in females (12.3/100,000 vs 7.3/100,000). The annual incidence of Takayasu arteritis is 3.3/million in the adult population using the ACR 1990 criteria and 1.1/million using the ACR/EULAR 2022 criteria. Conclusion This is the first study that reports the incidence of all objectively diagnosed large vessel vasculitis in a stable population in Norfolk county. The incidence of GCA rose with the establishment of a fast-track pathway and its peak may have been affected by the SARS-CoV-2 pandemic. GCA is commoner in females and peaks in the 8th and 9th decades. Disclosure C.B. Mukhtyar: None. C. Beadsmoore: None. F. Coath: None. G. Ducker: None. K. Sisson: None. R.A. Watts: None. OA33 Table 1. Number of cases Incidence (per 100,000 in age >50) Age 6th decade 9 9.9 7th decade 53 54.4 8th decade 109 166.4 9th decade 63 168.5 10th decade 6 78.7 Gender Female 150 12.3 Male 79 7.3 Year of diagnosis 2011 14 6.1 2012 14 6.1 2013 14 6.1 2014 21 9.1 2015 11 4.8 2016 16 6.9 2017 29 12.6 2018 40 17.3 2019 43 18.6 2020 27 11.7