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Interleukin-2 Receptor (CD25) Substance Concentration in Serum or Plasma

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

This test measures the amount of interleukin-2 receptor protein in your blood. It helps assess immune system activity, particularly in conditions involving T-cell activation.

Quick summary

["This test may help diagnose or monitor autoimmune diseases, infections, or certain cancers."]

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

Key facts at a glance

LOINC
38352-1
Short code
Il2Recep Spec-aCnc
Synonyms
Il2Recep Spec-aCnc
Category
coagulation
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

What Does This Test Measure?

The interleukin-2 receptor (CD25) is a protein that binds to interleukin-2, a signaling molecule involved in immune cell activation. Elevated levels may indicate an overactive immune response, such as in autoimmune disorders or chronic infections. Lower levels could suggest immune suppression or certain cancers.

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms or conditions linked to abnormal immune activity, such as rheumatoid arthritis, lupus, or certain types of lymphoma. It may also be used to monitor treatment responses in these cases.

Common Conditions Monitored

This test is often used in the evaluation of autoimmune diseases (e.g., rheumatoid arthritis, lupus), chronic infections, or to assess immune function in patients receiving immunosuppressive therapy.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The blood is processed to separate serum or plasma, which is then analyzed in a laboratory using an immunoassay method to detect the interleukin-2 receptor protein.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IL-2 Receptor (CD25) Level

Frequently asked questions

How is this test used in clinical practice?
Elevated levels of interleukin-2 receptor (CD25) are commonly associated with conditions where T-cells are overactivated, such as in autoimmune diseases or certain cancers. For example, high levels may indicate active disease in rheumatoid arthritis or lupus. Conversely, low levels might suggest immune suppression or treatment effects. Always discuss results with your healthcare provider, as interpretation depends on your specific medical context.
What does it mean if my test results are abnormal?
Abnormal results may signal an underlying condition requiring further evaluation, such as an autoimmune disorder, infection, or a need for immune-modulating treatment. Your provider will review the results alongside your medical history and other tests to determine the next steps.
How often should I get this test?
The frequency of testing depends on your medical condition and treatment plan. Your healthcare provider will determine how often this test should be repeated, typically based on symptoms, disease progression, or response to treatment.
  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