ACR/EULAR 2022 Classification Criteria for Microscopic Polyangiitis Save
The 2022 ACR/EULAR classification criteria for microscopic polyangiitis (MPA) have been developed, validated and are now ready for use in clinical research.
An international cohort of patients with vasculitis or comparator diseases were recruited to first develop criteria and then validate criteria.
The development group included 149 MPA cases and 408 comparators. Validation was tested on an additional 142 cases of MPA and 414 comparators. Criteria were developed from 91 variables, with regression analysis identifying 10 items for MPA; 6 of which were retained as final criteria.
The final criteria and their numeric weights included:
- perinuclear antineutrophil cytoplasmic antibody (ANCA) or anti-myeloperoxidase-ANCA positivity (+6)
- pauci-immune glomerulonephritis (+3)
- lung fibrosis or interstitial lung disease (+3)
- sino-nasal symptoms or signs (−3)
- cytoplasmic ANCA or anti-proteinase 3 ANCA positivity (−1)
- eosinophil count ≥1×109/L (−4).
The diagnosis of MPA required: excluding vasculitis mimics, plus, small- or medium-vessel vasculitis, and a score of ≥5 points. These criteria have a sensitivity of 91% and a specificity of 94%.