Skip to content

Myeloperoxidase Activity in Blood Cells (Qualitative)

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

This test checks whether your white blood cells produce myeloperoxidase, an enzyme important for fighting infections.

Quick summary

["Assesses enzyme function in immune cells for potential underlying conditions."]

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

Key facts at a glance

LOINC
107074-7
Short code
Myeloperoxidase Cells NFr Bld FC
Synonyms
Myeloperoxidase Cells NFr Bld FC
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like recurrent infections, unexplained fatigue, or signs of an immune disorder. It could also be part of evaluating conditions like chronic granulomatous disease (CGD), a rare genetic disorder affecting white blood cells.

What to Expect Before the Test

No special preparation is needed. You’ll likely have a simple blood draw from a vein in your arm. The test may be done as part of a routine blood panel or specifically for suspected immune-related issues.

What the Results Mean

A positive result (detectable enzyme activity) usually means your white blood cells are functioning normally in producing myeloperoxidase. A negative or reduced result may suggest a genetic or immune disorder affecting these cells.

Common Conditions Linked to This Test

This test is often used to diagnose chronic granulomatous disease (CGD) or to monitor immune function in patients with suspected or known white blood cell disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Myeloperoxidase plays a critical role in the immune response by producing reactive oxygen species that kill bacteria and fungi. Deficiencies in this enzyme can impair infection-fighting abilities, leading to severe, recurrent infections in affected individuals.

Short name

Myeloperoxidase (MPO) Qualitative Test

Frequently asked questions

What does a positive result mean?
A positive result indicates that myeloperoxidase is present in your white blood cells, suggesting normal enzyme production. This typically means your immune cells are functioning as expected in this regard.
Can this test be used to diagnose chronic granulomatous disease?
Yes, this test is a key part of diagnosing chronic granulomatous disease when combined with other clinical findings, such as recurrent infections or family history. However, additional testing may be needed for confirmation.
Does this test require fasting?
No fasting is required for this test. It is a simple blood draw and does not depend on dietary preparation.
  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