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Interleukin-5 (IL-5) concentration in serum/plasma

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

This test measures the amount of interleukin-5, a protein involved in the immune system that helps regulate the production of certain white blood cells.

Quick summary

["IL-5 helps your immune system respond to allergies and infections by controlling inflammation and immune cell activity."]

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

Key facts at a glance

LOINC
70084-9
Short code
Il5 CSF-mCnc
Synonyms
Il5 CSF-mCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Is IL-5 Used For?

IL-5 is primarily measured in research or specialized clinical settings to study immune responses, particularly in conditions involving chronic inflammation, allergies, or autoimmune diseases. It may also be evaluated in cases where immune cell function is suspected to be abnormal.

How Is the Sample Collected?

A blood sample is drawn from a vein, usually in your arm, using a needle. The blood is then processed to separate the serum or plasma for testing.

What Might Affect Results?

Several factors could influence IL-5 levels, including recent infections, immune system activity, medications (especially those affecting inflammation or immune response), and underlying health conditions like allergies or autoimmune disorders.

When Might You Need This Test?

Your healthcare provider may order this test if you have symptoms or conditions linked to immune system dysfunction, such as chronic inflammation, allergic reactions, or suspected immune-related diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated IL-5 levels may suggest active allergic responses, certain autoimmune conditions, or chronic inflammatory diseases. Lower levels might indicate suppressed immune activity or conditions affecting immune regulation, though interpretation depends on clinical context and other test results.

Short name

IL-5 Level

Frequently asked questions

Why might my doctor want to check my IL-5 level?
Your doctor may recommend this test if they suspect an immune-related condition, such as allergies, asthma, or an autoimmune disorder, that affects how your body produces certain white blood cells.
Is there anything I should do to prepare for this test?
No special preparation is usually needed, but avoid taking medications that might affect immune function (like steroids) 24 hours before the test if instructed by your provider.
Will the results affect my treatment?
Results may help guide treatment decisions, especially for conditions like allergies or autoimmune diseases, but final decisions depend on your overall health and medical history.
  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