Epidemiology of ANCA associated vasculitis

• annual incidence of ANCA-associated vasculitis (AAV) in Norfolk during 1988-2010 was estimated to be 19.5/million (GPA (Wegener) 11.3/million, MPA (microscopic polyangiitis) 5.9/million) with a prevalence of 255/million (1)
  • AAV entities are rare diseases with combined prevalence estimated at between 90 and 144 per million, and with annual incidence of around 20 per million (2)
• peak age at diagnosis was 65-74 years, with a male preponderance
  • high age at onset has been confirmed from other centres in Europe (Spain and Scandinavia)
  • a cyclical pattern of occurrence has been noted for GPA but not MPA
• approximately 85% to 90% of patients with GPA, 70% of those with MPA and approximately 30% to 40% of patients with EGPA are ANCA-positive (2)
• there are geographical differences in the incidence of AAV
  • for example a comparative study in Europe using the same classification criteria in three populations (Lugo, North-western Spain; Norwich, UK; and Tromsø, Northern Norway) reported that GPA was more common in Norway than in Spain, while MPA had the reverse distribution
  • in South-East Asian populations (Japan, China) myeloperoxidase (MPO)-AAV is relatively more common than vasculitis associated with antibodies to PR3 (PR3-AAV), although the overall incidence of AAV is similar

References:

1. ARC Autumn 2012. Topical Reviews - ANCA-associated vasculitis; 1:1-12.
2. Bala MM et al. Anti-cytokine targeted therapies for ANCA-associated vasculitis. Cochrane Database of Systematic Reviews 2020, Issue 9. Art. No.: CD008333.