LAUSR

There is lack studies about performance of new criteria set for ANCA-Associated Vasculitis (AAV) in Latin-America.To validate the new classification criteria for AAV in a real-life cohort of patients with these conditions.We performed a review of medical records from January 1990 to December 2019 at Hospital Nacional Guillermo Almenara Irigoyen from Peru. AAV was diagnosed by experienced rheumatologists based on the ACR 1990 criteria, Chapel Hill 2012 consensus, EMEA criteria and their experience and clinical acumen. Granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA) were diagnosed. Renal limited vasculitis was considered as MPA. To evaluate the performance of the new criteria, we classified all patients using “former criteria set” (including the 1990 ACR criteria for GPA and EGPA and the 1994 Chapel Hill Consensus Conference for MPA) and the EMEA (European Medicines Agency) criteria set. At the same time, we classified all patients using the ACR/EULAR Provisional criteria (new criteria set). The values for sensitivity, specificity and level of agreement (using Cohen’s kappa) of all sets of criteria were calculated using the clinical diagnosis as gold standard.Two hundred twelve patients were identified; 12 of them were excluded (eight did not have ANCA and four had incomplete data). Female/male ratio was 1.9:1 [130 (65%)/70 (35%)] and their mean (SD) age at diagnosis was 59.3 (12.6) years. One hundred fifty-four (77%) had MPA, 41 (20.5%) GPA and 5 (2.5%) EGPA. One hundred ninety-six patients had ANCA-IIF results [p-ANCA: 131 (66.8%), c-ANCA: 43 (21.9%), negative-ANCA: 22 (11.3%)] and 190 patients had ANCA-ELISA results [MPO: 129 (67.9%), PR3: 37 (19.5%), negative-ANCA: 24 (12.6%)]. Type of diagnosis according to criteria set used is depicted in Table 1. The new criteria set had better agreement (kappa: 0.653) than the EMEA criteria (kappa: 0.506) and the former criteria set (kappa: 0.305). Performance of the criteria sets is depicted in Table 2.Table 1.Type of AAV according to criteria set used.TYPE OF AAVClinical diagnosisFormer criteriaNew criteriaEMEAcriteriaMPA, n (%)154 (77)76 (38)137 (68.5)110 (56.0)GPA, n (%)41 (20.5)30 (15)39 (19.5)39 (19.5)EGPA, n (%)5 (2.5)2 (1)4 (2)2 (1.0)Not classifiable, n (%)NA92 (46)20 (10)44 (22.0)PAN5 (2.5)PAN: Polyarteritis nodosa. NA: Not applicable.Table 2.Performance of the different criteria sets in AAV patients.DIAGNOSISCRITERIA SETSESPKappaMPAFormer49.4100.00.309EMEA69.993.90.471New87.093.50.713GPAFormer68.398.70.744EMEA92.799.40.938New80.596.20.781EGPAFormer40.0100.00.565EMEA40.0100.00.565New60.099.50.659SE: Sensitivity. SP: Specificity.The ACR/EULAR Provisional Criteria for AAV have better agreement with the clinical diagnosis of AAV in Latin-American patients from a real-life cohort.Victor Pimentel-Quiroz: None declared, Alfredo Sánchez-Torres: None declared, Cristina Reategui Sokolova: None declared, Rocío Violeta Gamboa Cárdenas Grant/research support from: Pfizer, César Sánchez-Schwartz: None declared, Mariela Medina Chinchon: None declared, Francisco Zevallos Miranda: None declared, Erika Noriega: None declared, Jose Alfaro Lozano Speakers bureau: Lilly, Jorge-M Cucho-V: None declared, Zoila Rodriguez Bellido: None declared, Cesar Pastor Asurza: None declared, Eduardo Acevedo-Vásquez: None declared, Risto Perich Campos Consultant of: Pfizer, Speakers bureau: Pfizer, Graciela S Alarcon: None declared, Manuel F. Ugarte-Gil Grant/research support from: Jannsen, Pfizer