Home
HelpTest Code LAB3206 Proteinase 3 Antibodies, IgG, Serum
Reporting Name
Proteinase 3 Ab (PR3), SUseful For
Evaluating patients with clinical features of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, specifically granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis
Distinguishing between GPA and other forms of ANCA-associated vasculitis, in conjunction with myeloperoxidase antibody and cytoplasmic neutrophil antibody testing
Following treatment response or monitoring disease activity in patients with proteinase 3 antibodies
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumAdditional Testing Requirements
To distinguish between granulomatosis with polyangiitis and other forms of anti-neutrophil cytoplasmic antibody-associated vasculitis, also order MPO / Myeloperoxidase Antibodies, IgG, Serum and ANCA / Cytoplasmic Neutrophil Antibodies, Serum; alternatively, VASC / Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum may be ordered instead, which initially tests for MPO and proteinase 3 antibodies, with reflex to ANCA when appropriate.
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.35 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 21 days |
| Frozen | 21 days |
Reference Values
<0.4 U (negative)
0.4-0.9 U (equivocal)
≥1.0 U (positive)
Reference values apply to all ages.
Day(s) Performed
Monday through Saturday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83516
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PR3 | Proteinase 3 Ab (PR3), S | 74106-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PR3 | Proteinase 3 Ab (PR3), S | 74106-6 |
Cautions
A positive result for proteinase 3 (PR3)-anti-neutrophil cytoplasmic antibodies (ANCA), myeloperoxidase (MPO)-ANCA, or ANCA by indirect immunofluorescence is not diagnostic for any ANCA-associated vasculitis and must be interpreted in the clinical context of the patient.
Negative results for PR3-ANCA, MPO ANCA, and ANCA by IIF do not exclude the possibility of ANCA-associated vasculitis.
Monitoring reactivity of PR3-ANCA or MPO-ANCA should not be relied upon exclusively to evaluate response to treatment or to assess for risk of disease flare.
Report Available
2 to 3 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
NY State Approved
YesMethod Name
Multiplex Flow Immunoassay
Secondary ID
82965Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.