Ordering Recommendation

Use to monitor previously established MPO/PR3 antibodies or confirm an IFA ANCA positive test result. Test does not include ANCA testing by IFA. For ANCA testing, refer to the available panel tests. For the workup of suspected vasculitis, refer to ANCA-Associated Vasculitis Profile (ANCA/MPO/PR3) (3003745). For patients with a history of vasculitis, refer to Myeloperoxidase (MPO) Antibody and Serine Proteinase 3 (PR3) Antibody with Reflex to Anti-Neutrophil Cytoplasmic Antibody, IgG by IFA (3003746).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)

Storage/Transport Temperature


Unacceptable Conditions

Plasma, urine, or other body fluids.  Contaminated, hemolyzed, or severely lipemic specimens.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Semi-Quantitative Multiplex Bead Assay




1-2 days

Reference Interval

Test Number
Reference Interval (AU\mL)
  Myeloperoxidase (MPO) Ab, IgG 19 AU/mL or less
  Serine Proteinase 3 (PR3) Ab, IgG 19 AU/mL or less

Interpretive Data

Approximately 90% of patients with a P-ANCA pattern by IFA have antibodies specific for MPO. 
Approximately 85% of patients with a C-ANCA pattern by IFA have antibodies specific for PR3.

Component Interpretation
Myeloperoxidase (MPO) Antibody Negative           19 AU/mL or less
Equivocal          20-25 AU/mL
Positive           26 AU/mL or greater
Serine Proteinase 3 (PR3) Antibody Negative          19 AU/mL or less
Equivocal         20-25 AU/mL
Positive          26 AU/mL or greater

Compliance Category



Hotline History


CPT Codes

83516 x2


Component Test Code* Component Chart Name LOINC
0050526 Myeloperoxidase (MPO) Ab, IgG 6969-0
0050527 Serine Proteinase 3 (PR3) Ab, IgG 6968-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • 3-ANCA
  • ANCA Antibodies
  • Anticytoplasmic Autoantibodies
  • c-ANCA
  • MPO
  • Myeloperoxidase Antibodies
  • p-ANCA
  • PR3
  • PR3-ANCA
  • Proteinase 3 Antibodies
  • Serine Proteinase 3
MPO/PR3 (ANCA) Antibodies