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Interleukin-2 (IL-2) in Serum or Plasma

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

This test measures the amount of interleukin-2, a protein involved in regulating the immune system, found in your blood.

Quick summary

["IL-2 helps your immune cells communicate and respond to infections or other immune challenges."]

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

Key facts at a glance

LOINC
70078-1
Short code
Il2 Fld-mCnc
Synonyms
Il2 Fld-mCnc
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 order this test to evaluate immune function, assess responses to treatments for autoimmune diseases, or investigate symptoms like fatigue, infections, or unusual immune reactions. It can also be part of monitoring for conditions like cancer or organ transplant rejection.

What to Expect Before the Test

No special preparation is usually needed. You may have a blood draw from a vein in your arm. If you’re taking medications that affect immune function, let your provider know.

What the Results Mean

Results can vary widely depending on health status, age, and medical conditions. Elevated levels may suggest overactive immune responses, while lower levels could indicate immune suppression. Your provider will interpret results in the context of your overall health.

Common Conditions Monitored

IL-2 testing is often used in research or specialized clinical settings for conditions like autoimmune diseases (e.g., rheumatoid arthritis), certain cancers (e.g., melanoma), or after organ transplants to check immune activity.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IL-2 Level

Frequently asked questions

Is there a standard reference range for IL-2?
No standard reference range exists because IL-2 levels fluctuate based on immune activity, time since exposure to triggers, and individual health. Your provider will use clinical context to assess results.
Can IL-2 levels change with diet or lifestyle?
Diet and lifestyle factors may indirectly influence immune function, but direct effects on IL-2 levels are not well-documented. Focus on maintaining overall health and discussing any concerns with your provider.
Why might my IL-2 test be done repeatedly?
Repeated testing could be part of monitoring a treatment response (e.g., for autoimmune diseases or cancer), tracking immune recovery post-transplant, or evaluating chronic immune conditions. Always ask your provider why the test is being repeated.
  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