ACR/EULAR classification criteria for microscopic polyangiitis

The American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for microscopic polyangiitis is a clinical tool designed to aid in the diagnosis of this specific form of vasculitis. The target patient population includes individuals presenting with symptoms suggestive of small- or medium-vessel vasculitis. The primary components of the ACR/EULAR classification criteria for microscopic polyangiitis encompass both clinical and laboratory, imaging, and biopsy criteria. The clinical criteria include evidence of nasal involvement, such as bloody discharge, ulcers, crusting, congestion, blockage, or septal defect/perforation. The laboratory, imaging, and biopsy criteria include a positive test for perinuclear antineutrophil cytoplasmic antibodies or anti-myeloperoxidase antibodies, fibrosis or interstitial lung disease on chest imaging, pauci-immune glomerulonephritis on biopsy, a positive test for cytoplasmic antineutrophil cytoplasmic antibodies or anti-proteinase 3 antibodies, and a blood eosinophil count of 1×10**9/L or higher. The ACR/EULAR classification criteria for microscopic polyangiitis also includes entry criteria, which require evidence of small- or medium-vessel vasculitis on imaging and the exclusion of alternative diagnoses that mimic vasculitis. These criteria ensure that the tool is applied to the appropriate patient population and that other potential causes of the patient's symptoms have been ruled out.

Reference

Ravi Suppiah, Joanna C Robson, Peter C Grayson et al. 2022 American College of Rheumatology / European Alliance of Associations for Rheumatology classification criteria for microscopic polyangiitis. Ann Rheum Dis. 2022 Mar;81(3):321-326.