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Myeloperoxidase Activity in Blood (Fluid)

Published: August 9, 2026Updated: August 16, 2026

This test measures the activity of myeloperoxidase, an enzyme found primarily in white blood cells (neutrophils). It helps assess immune function and inflammation-related conditions.

Quick summary

["Myeloperoxidase activity may be checked to evaluate immune responses or certain blood disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
63538-3
Short code
Myeloperoxidase Ab Fld-aCnc
Synonyms
Myeloperoxidase Ab Fld-aCnc
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 This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms or conditions linked to abnormal white blood cell activity, such as infections, autoimmune diseases, or certain blood cancers. It could also be part of a broader evaluation for conditions affecting neutrophil function or inflammation.

What to Expect Before the Test

No special preparation is typically needed. You may have a blood sample drawn from a vein in your arm. If you’re on blood-thinning medication, let your provider know before the test.

What the Test Results Mean

Results are not provided as a single numeric range since myeloperoxidase activity varies by method and specimen type. Your provider will interpret the result in relation to your clinical picture, symptoms, and other test results.

Common Conditions Monitored

This test may be used to monitor conditions like chronic granulomatous disease (a rare genetic disorder affecting white blood cells), infections, or inflammatory processes. It can also help diagnose or track certain cancers or autoimmune diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Myeloperoxidase Activity

Frequently asked questions

How is myeloperoxidase activity tested?
Myeloperoxidase activity is measured using a blood sample (often serum or plasma) and typically involves an enzymatic assay that detects its oxidative activity. Results are qualitative or semi-quantitative, depending on the lab method.
What are the typical reference ranges?
Reference ranges for myeloperoxidase activity vary by lab method and specimen type. Since this is not a standard, widely reported test, your provider will discuss the result in the context of your health and other tests.
Can myeloperoxidase activity be affected by diet or medications?
Dietary factors or common medications (like blood thinners) may not directly affect myeloperoxidase activity, but they can influence overall health and test interpretation. Always discuss your medications and lifestyle with your provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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