Pos0968 anca-associated vasculitis incidence in a northern spanish health region, 1994-2022: a population-based study

Background Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) includes granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA) or microscopic polyarteritis (MPA). Precise estimation of the incidence of AAV has been difficult due to the absence of reliable diagnostic criteria. Objectives To estimate the incidence in a Northern Spanish population-based cohort. Methods Population-based study of 132 patients diagnosed with small vessel vasculitis between 1994 and 2022 in a tertiary hospital. Finally, 98 patients were included as AAV according to ACR/EULAR 2022 criteria [1]. Incidence was estimated by gender, age, and year of diagnosis. Results AAV was diagnosed in 98 (49 women/ 49 men) patients: GPA (n=47, 48%) MPA (n=37,37.8%) and EGPA (n=14, 14.3%). Annual incidences were estimated in AAV (Figure 1). GPA annual incidence in our population area in the 1994-2022 period was 2.81 per 1,000,000 people, 95% CI: 3.77-1.85 (2.82 [4.35-1.29] in males and 2.80 [4.50-1.09] in females). An upward trend in annual incidence over time was observed with rates ranging from 1.88 in 1994 to 6.84 in 2022 (weak correlation; r 2=0.2729). On the other hand, MPA annual incidence was 2.23 per 1,000,000 people (1.92 [3.55-0.27] in males and 2.46 [4.07-0.85] in females). Rates ranged from 1.88 in 1994 to 1.71 in 2022 with an upward trend over time (very weak correlation; r 2=0.0746). In the case of GEPA, annual incidence was 0.83 per 1,000,000 people, 95% CI: 1.72-0.06 (1.22 [2.74-0.30] in males and 0.46 [2.29-1.37] in females). As in the other types of AAV, there was an upward trend over time with variations of from 1.88 in 1999 to 3.42 in 2022 (weak correlation; r 2=0.3335). A comparison between different geographical areas is summarized in Table 1. Wide varia-tions in annual incidence per million were observed in all AAV (GPA 2.1-34; MPA 2.23-10.4; EGPA 0.64-2.7). The highest annual incidence of all AAV was observed in nordic countries and central Europe while the lowest in Southern Europe. Conclusion There seems to be a progressive increase in incidence of AAV over the years in the studied population. Annual incidence in our population was similar to that of other south-ern European countries. Reference [1]Yazici, Hasan et al Current opinion in rheumatology vol. 35,1 (2023): 1-5. Figure 1. Annual incidence of AAV in 1994-2022. Table 1. AAV incidence cases reported in the literature. Study, year Country, data source Time period Incident cases per million population GPA Incident cases per million population MPA Incident cases per million population EGPA Pearce, F. A. et al. 2016 Nottingham, UK, population register 1656-1663 8.2 13.4 1.5 Nilsen, A. T. et al. 2020 Tromso, Norway, population register 1999-2013 15.6 10.4 2.7 Mohammad, A. J et al. 2009 Lund, South Sweden, population register 1997-2006 9.8 10.1 0.9 Takala, J. H et al. 2008 Finland, analysis national discharge data 1996-2000 9.3 NA NA Hellmich, B. et al. 2021 Germany, analysis insurance claims database 2013-2016 34 13 NA Dadoniene, J. et al 2005 Vilnius, Lithuania, analysis hospital database 1990-1999 2.1 3 1.3 Panagiotakis, S. H. et al. 2009 Crete, Greece, analysis hospital database 1995-2003 6.6 10.2 NA Romero-Gómez, C. et al. 2004 Malaga, Spain, retrospectiva population. 1994-2010 2.1 3.4 0.64 Catanaso, M. et al. 2014 Reggio Emilia, Italia, analysis hospital discharge database 2004-2009 3.4 NA NA Vinit, J. et al. 2006 Burgundy, France, analysis hospital discharge database 1998-2008 NA NA 1.2 Kanecki, K. et al. 2018 Poland, analysis hospital discharge database 2008-2013 NA NA 1.5 Kanecki, K. et al. 2018 Poland, analysis hospital discharge database 2011-2015 7.7 NA NA Present study, 2023 Northern Spain. 1999-2022 2.81 2.23 0.83 Acknowledgements: NIL. Disclosure of Interests Salma Al Fazazi: None declared, Alba Herrero-Morant: None declared, Vanesa Calvo-Río: None declared, Mónica Renuncio García: None declared, Clara Escagedo Cagigas: None declared, Maria Rodriguez Vidriales: None declared, Ricardo Blanco Speakers bureau: Abbvie, Lilly, pfizer, Roche, Bristol-Myers, Janssen, Galapagos and MSD., Consultant of: Abbvie, Lilly, pfizer, Roche, Bristol-Myers, Janssen and MSD., Grant/research support from: Abbvie, MSD, Novartis and Roche.