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Urine Free Light Chain (λ) Mass Concentration

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

This test measures the amount of free lambda (λ) light chains in your urine, which can help detect certain conditions affecting your immune system or kidneys.

Quick summary

["This test helps monitor protein-related disorders, including multiple myeloma or kidney disease."]

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

Key facts at a glance

LOINC
38178-0
Short code
Lambda LC Free Ur-mCnc
Synonyms
Lambda LC Free Ur-mCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

Free light chains are small protein fragments produced when antibodies break down. When abnormal antibody production occurs (e.g., in multiple myeloma), these fragments can appear in urine. Detecting them early can help diagnose or manage conditions like plasma cell dyscrasias or kidney damage.

What to Expect Before the Test

No special preparation is needed. You’ll provide a urine sample, typically collected in the morning. Drink plenty of water the day before if you’re unsure about timing, but avoid excessive fluid intake right before testing.

Sample Collection Process

Your healthcare provider will give you a clean container to collect your urine. Empty your bladder completely, then collect the urine midstream. Seal the container properly and return it to the lab immediately.

What the Results Mean

Elevated levels may indicate conditions like multiple myeloma, kidney disease, or other plasma cell disorders. Your doctor will interpret results in the context of your medical history and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Free Light Chain Urine Test

Frequently asked questions

What causes elevated free light chains in urine?
Elevated free light chains can result from conditions like multiple myeloma (a cancer of plasma cells), kidney disease, or other immune system disorders. They may also appear in people with benign conditions like chronic kidney disease or certain infections.
How often should I get this test?
Your doctor will determine frequency based on your diagnosis, symptoms, and treatment plan. Regular monitoring may be needed if you have a known condition affecting light chains, such as multiple myeloma.
Can diet or medications affect this test?
Certain medications (e.g., some diuretics) or dietary changes (e.g., high-protein diets) may influence urine protein levels, but they rarely affect free light chain measurements directly. Always discuss any concerns with your healthcare provider.
  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