David A. Cabral, Else S. Bosman, Nick McPhate, Simranpreet Kaur Mann, K. Toor, Kimberly Morishita, Raashid Luqmani, Michael W. Beresford, James Bistolarides, Sarah Campillo, Sirirat Charuvanij, Kathryn Cook, Paul Dancey, Marietta de Guzman, Samundeeswari Deepak, B. Anne Eberhard, Melissa Elder, Samuel J Gagne, Katie Harrison, Adam Huber, Archana Khan, Susan Kim, Marisa S Klein‐Gitelman, Tzielan Lee, S. C. Li, Neil Martin, Flora McErlane, L. Nandini Moorthy, Alvaro Orjuela, Jonathan Park, Phil Riley, Alan Rosenberg, Susan Shenoi, Vidya Sivaraman, Sodality Sutnga, Tamara Tanner, Stacey E. Tarvin, M. Twilt, Linda Wagner‐Weiner, Rae S.M. Yeung, Kelly L. Brown, for the ARChiVe Investigators Network within the PedVas Initiative
OBJECTIVE: To assess the 2022 American College of Rheumatology (ACR)/EULAR classification criteria for antineutrophil cytoplasmic antibody-associated vasculitis (AAV) in children with chronic small-to-medium vessel vasculitis. METHODS: A cohort of 574 patients, identified by physician's diagnosis (MD-diagnosis) in A Registry of Childhood Vasculitis, was classified by computation of registry data as having granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or eosinophilic GPA after applying (1) ACR/EULAR AAV criteria and (2) pediatric-adapted European Medicines Agency (Ped-EMA) classification algorithm (incorporating Ankara GPA criteria). Venn diagrams compared the resulting GPA and MPA cohorts with MD-diagnosis. Sensitivity and specificity of criteria for GPA were evaluated against MD-diagnosis. Fisher exact test evaluated differences in the frequencies of individual clinical features in GPA versus MPA. RESULTS: Comparing ACR/EULAR criteria against the Ped-EMA algorithm for classifying AAV, more patients were classified as GPA or MPA (n = 396 vs 360, respectively), fewer had GPA (n = 261 vs 288, respectively), more had MPA (n = 135 vs 72, respectively), and fewer GPA cases coclassified as MPA (12% vs 28%, respectively); there were more differences between GPA and MPA in Pediatric Vasculitis Activity Score-defined clinical features (n = 14 vs 10, respectively). When classifying GPA by ACR/EULAR or Ankara criteria, sensitivity (74.5% vs 72.1%, respectively) was comparable, and specificity for ACR/EULAR criteria (93.9% vs 79.9%, respectively) was improved. CONCLUSION: The 2022 ACR/EULAR classification criteria for AAV perform at least as well as previous pediatric criteria and provide categorical MPA criteria where none existed previously; the criteria for GPA and MPA now specifically differentiate each other, with more differences between them in the frequencies of clinical features. Our findings support the preferential use of ACR/EULAR over Ankara criteria for GPA in pediatrics.