{"id":"pr3-anca","name":"PR3-ANCA (Anti-Proteinase 3 Antibody)","shortName":"PR3-ANCA","aliases":["PR3 Antibody","PR3 ANCA","Proteinase 3 Antibody","Anti-PR3","PR3 Ab (ANCA)","Proteinase 3 IgG","Proteinase 3 Antibody (PR3)","Proteinase 3 Antibodies, IgG, Serum","Proteinase-3 Antibody","Proteinase 3 Ab (PR3), S","Serine Proteinase 3 (PR3) Antibody","Serine Proteinase 3 (PR3) Ab, IgG","Antiproteinase 3 (PR3) Antibodies","Anti-PR3 Antibodies","Anti-PR3 Antibody","Anti-PR3 IgG","PR-3 Antibody","Anti-Proteinase 3 Antibody","PR3-ANCA IgG","Proteinase 3 ANCA"],"abbreviations":["PR3-ANCA","PR3 Ab","Anti-PR3","PR3 ANCA"],"loinc":[{"code":"46267-1","primary":true},{"code":"6968-2","primary":false},{"code":"74106-6","primary":false},{"code":"48408-9","primary":false},{"code":"63310-7","primary":false}],"specimen":"serum","units":[{"ucum":"[arb'U]/mL","display":"AU/mL"}],"referenceRanges":[{"population":"Adults","low":0,"high":19,"unit":"[arb'U]/mL","unitDisplay":"AU/mL","note":"ARUP's multiplex bead assay, reported in AU/mL: 19 or less is negative, 20 to 25 is equivocal and 26 or more is positive. Other labs use different scales, and the numbers cannot be compared. Quest's immunoassay reports an antibody index (AI): below 1.0 AI is 'no antibody detected' and 1.0 AI or more is 'antibody detected'. Mayo Clinic Laboratories reports units (U): below 0.4 is negative, 0.4 to 0.9 equivocal and 1.0 or more positive. Labcorp's fluoroenzyme immunoassay (EliA) reports U/mL: below 2.0 is negative, 2.0 to 3.0 equivocal and above 3.0 positive. This range applies only to results printed in AU/mL, so use the cutoff and flag on your own report.","sources":[{"title":"Serine Proteinase 3 (PR3) Antibody (test 0050527)","url":"https://ltd.aruplab.com/Tests/Pub/0050527","publisher":"ARUP Laboratories"},{"title":"MPO/PR3 (ANCA) Antibodies (test 0050707)","url":"https://ltd.aruplab.com/Tests/Pub/0050707","publisher":"ARUP Laboratories"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"A blood test for antibodies against proteinase 3, a protein in white blood cells. A positive result is most linked to granulomatosis with polyangiitis, a type of vasculitis.","url":"https://bloodtesttracker.com/markers/pr3-anca","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}