Myeloperoxidase Antibodies, IgG
Label Mnemonic: MPO
Epic code: LAB1326
Order form: Laboratory Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 83520
Specimen(s):
Serum
Collection Medium:
Red top tube 5 mL (Clot Activator)
Minimum:
Adult - 5 mL; red top tube
Pediatric - 2 mL; red top tube
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
3 hours (upon receipt in laboratory)
Reference Range:
Negative: < 0.4 antibody index AI
Equivocal: 0.4-0.9 AI
Positive: 1.0 AI or greater
Interpretive Data:
Myeloperoxidase (MPO) antibodies are used for evaluating patients suspected of having immune-mediated vasculitis, especially microscopic polyangiitis (MPA), when used in conjunction with clinical history, physical examination, and other autoantibody tests.

Autoantibodies to MPO occur in several diseases and may be involved in the pathogenesis of MPA. MPO autoantibodies are not specific for MPA and may also be detected in patients with Goodpasture syndrome, systemic necrotizing glomerulonephritis, and Churg-Strauss syndrome.

Titers to MPO antibodies may be useful to follow treatment response.
Comments:
Assay methodology and reference ranges changed February 5, 2013.

References:
Russel KA et al. Detection of anti-neutrophil cytoplasmic antibodies under actual clinical testing conditions. Clin Immunol 2002; 103:196- 203.
Methodology:
Multiplex flow immunoassay
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells.
Separate plasma or serum into labeled container and cap.
Sample Storage:
Refrigerate.
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
83520