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Immunoglobulin Lambda Light Chain in Serum (Free Light Chains)

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

This test measures the amount of free lambda light chains, a component of antibodies, in your blood. It helps identify conditions affecting antibody production or breakdown.

Quick summary

["Free light chains can signal underlying immune system disorders or kidney issues."]

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

Key facts at a glance

LOINC
74867-3
Short code
IgM lambda SerPl-mCnc
Synonyms
IgM lambda SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 recommend this test if you have symptoms like fatigue, weight loss, or unexplained kidney problems. It’s also used in diagnosing conditions such as multiple myeloma, lymphoma, or certain autoimmune diseases.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. If you’re nervous, let your provider know—they can offer ways to stay comfortable.

What the Test Results Mean

High levels of free lambda light chains may indicate conditions like multiple myeloma, where abnormal antibody production occurs. Low or normal levels are typically within expected ranges, but results depend on your overall health.

Common Conditions Linked to This Test

This test is often used alongside other blood tests to diagnose or monitor conditions such as plasma cell dyscrasias (like multiple myeloma), Waldenström macroglobulinemia, or certain types of lymphoma.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal levels of free light chains can signal serious health issues, including cancer of the plasma cells (multiple myeloma) or kidney problems. Monitoring these levels helps track disease progression or response to treatment.

Short name

Free Lambda Light Chains

Frequently asked questions

What causes elevated free lambda light chains?
Elevated levels are most commonly linked to multiple myeloma or other plasma cell disorders. Rarely, they may appear in conditions like lymphoma or certain autoimmune diseases, but further testing is needed to confirm.
How often should this test be repeated?
If your results are abnormal, your doctor may order follow-up tests or repeat this test every few months to monitor changes, depending on your treatment plan.
Does diet or exercise affect this test?
Diet or exercise typically do not directly impact free light chain levels, but maintaining overall health and following your doctor’s advice for managing any related conditions is important.
  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