Myeloperoxidase (MPO) Antibody

Ordering Recommendation

When used in conjunction with other autoantibody tests (ANCA, PR3), may aid in evaluating suspected immune-mediated vasculitis, especially microscopic polyangiitis (MPA). May be useful to monitor MPA disease and/or treatment response.

Panel tests are available. 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).

Mnemonic

MPO-AB

Performed

Mon-Sat

Methodology

Semi-Quantitative Multiplex Bead Assay

Reported

1-3 Days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation:

Collect:

Serum separator tube.

Specimen Preparation:

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

Storage/Transport Temperature:

Refrigerated.

Unacceptable Conditions:

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

Remarks:

Stability:

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

Reference Interval

19 AU/mL or less

Negative

20-25 AU/mL

26 AU/mL or greater

Equivocal

Positive

Interpretive Data

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