Large vessel involvement in antineutrophil cytoplasmic antibody-associated vasculitis

Objectives ANCA-associated vasculitis (AAV) is currently categorized under the small vessel vasculitides. There is limited knowledge about large vessel involvement in AAV (L-AAV), mainly described in case reports and small series. L-AAV can involve temporal arteries (TA-AAV), aorta (A-AAV), and periaortic soft tissue (PA-AAV). We sought to characterize the features of patients with L-AAV. Methods Patients older than 18 years at diagnosis of TA-AAV, A-AAV and PA-AAV seen at the Mayo Clinic, Rochester between 1 January 2000 and 31 December 2021 were identified through a proprietary medical text search algorithm. Patients were included if diagnosed with L-AAV, fulfilled 2022 ACR/EULAR classification criteria for GPA, MPA or EGPA, had positive ANCA test results, and had more than one outpatient or inpatient visit. Results The study cohort consists of 36 patients with L-AAV. Of those, 23 had p-ANCA and/or MPO-ANCA, and 13 had c-ANCA and/or PR3-ANCA. Mean (s.d.) age at AAV diagnosis was 63.4 (12.79) years; 20 (56%) were male. Seventeen patients had TA-AAV, 10 had A-AAV and 9 had PA-AAV. Most patients (n = 25, 69%) were diagnosed with large vessel vasculitis and AAV within a 1-year timespan. Twenty-five (69%) patients had histopathological confirmation of AAV diagnosis in a location other than temporal artery, aorta or periaortic soft tissue. Glucocorticoids (36/36), rituximab (19/36) and methotrexate (18/36) were the most frequent treatments. Conclusion This is the largest single-centre cohort of patients with L-AAV to date. AAV can involve large arteries, albeit infrequent. AAV-targeted therapy should be considered in patients with L-AAV.