2022 ACR/EULAR Microscopic Polyangiitis Classification Criteria
2022 ACR/EULAR microscopic-polyangiitis classification; a cumulative score ≥ 5 classifies as MPA, applied only after a small/medium-vessel-vasculitis diagnosis with mimics excluded.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Positive pANCA or anti-MPO antibody
- Yes
Result: 2022 ACR/EULAR 6/12 — ≥ 5: classify as microscopic polyangiitis.
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What the result means
- Threshold
- a cumulative score ≥ 5 classifies as microscopic polyangiitis (sensitivity 91%, specificity 94%).
What you enter
- Positive pANCA or anti-MPO antibody (+6)
- Pauci-immune glomerulonephritis on biopsy (+3)
- Fibrosis or interstitial lung disease on chest imaging (+3)
- Nasal involvement — bloody discharge, ulcers, crusting, congestion, blockage, or septal defect/perforation (-3)
- Positive cANCA or anti-PR3 antibody (-1)
- Blood eosinophil count ≥ 1 x10^9/L (-4)
How this is calculated
- Items
- 6 items summed, range -8 to +12: pANCA/MPO +6; +3 each for pauci-immune GN and fibrosis/ILD; nasal involvement -3; cANCA/PR3 -1; eosinophils ≥ 1 -4.
Suppiah R, Robson JC, Grayson PC, et al. 2022 American College of Rheumatology/EULAR classification criteria for microscopic polyangiitis. Arthritis Rheumatol. 2022;74(3):400-406. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.