Antibodies to Myeloperoxidase

Autoantibodies to Myeloperoxidase

Test Indications: Presence of MPO IgG antibodies may aid in evaluating suspected immune-mediated vasculitis, especially microscopic polyangiitis (MPA). May be useful to monitor MPA disease and/or treatment response.

MPO can be ordered as a standalone test to monitor antibody levels in patients with established vasculitis.  MPO is also automatically reflexed for samples positive for pANCA and those with Indeterminate ANCA results.

 A negative result does not necessarily exclude autoimmune disease.  Positive results should not be interpreted in isolation and must be correlated with relevant clinical findings.

Method of Analysis: The IDS MPO IgG assay is based on chemiluminescence technology. Patient serum is incubated with magnetic particles coated with the specific antigen.  Following the washing step after the first incubation, an anti-human IgG antibody labelled with acridinium is added, followed by a subsequent incubation step. The magnetic particles are captured using a magnet and a wash step performed to remove any unbound analyte. Trigger reagents are added; the resulting light emitted by the acridinium label is directly proportional to the concentration of anti-MPO IgG in the sample.   

Reference: IDS MPO Instructions for Use, IS-AI1701 V09, 18-11-2025