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Interferon Lambda-2 (IFNL2) and Interferon Lambda-1 (IFNL1) Serum Antibody Levels (Quantitative)

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

This test measures antibodies to two types of interferon lambda (IFNλ), proteins involved in immune response. These antibodies may be checked if you have conditions like hepatitis C or autoimmune diseases.

Quick summary

["This test helps assess immune system response to interferon lambda proteins, often linked to chronic hepatitis C treatment."]

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

Key facts at a glance

LOINC
60279-7
Short code
IL28B rs12979860 Bld/T Ql
Synonyms
IL28B rs12979860 Bld/T Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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 Is Done

Your healthcare provider may order this test if you’re undergoing treatment for hepatitis C with interferon-based therapies or if you have symptoms of an immune response, such as fatigue or flu-like symptoms. Antibodies to IFNλ can indicate how your body is reacting to the treatment.

What to Expect Before the Test

No special preparation is needed. You’ll have a blood sample drawn from a vein, usually in your arm. The process is quick and typically causes only mild discomfort.

What the Test Results Mean

Results show the concentration of antibodies against IFNλ1 and IFNλ2. High levels may suggest an immune response to the treatment, while low levels could indicate insufficient antibody production. Your provider will interpret results in the context of your medical history and treatment plan.

Common Conditions Monitored

This test is primarily used in hepatitis C patients receiving interferon-based therapies to monitor immune response and adjust treatment if needed. It may also be relevant for autoimmune conditions where IFNλ plays a role.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Monitoring Immune Response in Hepatitis C Treatment

Short name

IFNλ Antibody Profile

Frequently asked questions

What does a positive result mean?
A positive result (detectable antibodies) suggests your body is producing antibodies against interferon lambda proteins, which may be related to your immune reaction to treatment. This can help guide whether to continue, adjust, or stop interferon-based therapies.
How often will I need this test?
Frequency depends on your treatment plan. Your healthcare provider will determine how often this test is needed based on your specific situation, such as the type of interferon therapy you’re receiving or your overall health.
Can I eat or drink before this test?
You can eat and drink normally before this test, as no special preparation is required. However, always follow your provider’s instructions for any specific dietary or fasting guidelines they may have given you.
  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