Myeloperoxidase Antibody (Anti-MPO) in Serum/Plasma
This test measures the presence of antibodies directed against myeloperoxidase, an enzyme found in white blood cells. It may be used to diagnose or monitor certain autoimmune conditions.
["This test helps identify immune responses linked to inflammation or autoimmune diseases."]
Key facts at a glance
- LOINC
- 57777-5
- Short code
- MPO Ab + PR3 pnl Ser
- Synonyms
- MPO Ab + PR3 pnl Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you have symptoms suggestive of conditions like vasculitis (inflammation of blood vessels), autoimmune diseases, or certain types of arthritis. It could also be part of a broader evaluation for unexplained fevers, skin rashes, or organ involvement.
What Does a Positive Result Mean?
A positive result indicates the presence of anti-MPO antibodies, which may suggest an autoimmune response targeting these white blood cell enzymes. This can be associated with conditions like microscopic polyangiitis or other vasculitides, but results alone don’t confirm a diagnosis. Further clinical correlation and testing are needed.
What Does a Negative Result Mean?
A negative result means no detectable anti-MPO antibodies were found in your sample. This doesn’t rule out other possible causes of your symptoms, so your provider may recommend additional testing or monitoring.
How Is This Test Performed?
A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum or plasma, which is then tested for the presence of anti-MPO antibodies using an immunoassay method. This process typically takes a few days to complete.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Anti-MPO Antibody
Frequently asked questions
Anti-MPO antibodies are often linked to vasculitis, a group of diseases causing inflammation in blood vessels. They can help identify specific types of vasculitis, such as microscopic polyangiitis, and guide treatment decisions. Monitoring antibody levels over time may help assess disease activity or response to treatment.
Results from this test are usually available within 2 to 5 business days, depending on your lab’s processing schedule. Your healthcare provider will discuss the results with you during your follow-up visit.
While lifestyle factors like diet, stress, or physical activity may influence overall immune function, there’s no strong evidence that they directly affect anti-MPO antibody levels in the short term. Your provider may recommend lifestyle adjustments if they suspect they contribute to your symptoms beyond lab results.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy