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Serum or Plasma Free Light Chain Kappa (Immunoassay)

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

This test measures the amount of free kappa light chains (a protein fragment) in your blood, often checked when evaluating conditions like multiple myeloma or other blood disorders.

Quick summary

["Free kappa light chains help diagnose and monitor certain blood cancers and immune system disorders."]

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

Key facts at a glance

LOINC
17015-9
Short code
FLUBV IgG Ser-aCnc
Synonyms
FLUBV IgG Ser-aCnc
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 Is Done

Your healthcare provider may order this test if you have symptoms like unexplained fatigue, weight loss, frequent infections, or kidney problems. It may also be used to monitor treatment progress in conditions affecting plasma cells, such as multiple myeloma or lymphoma.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if your blood is drawn early in the morning. Bring any medications or supplements you’re currently taking to your appointment.

What the Test Involves

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but it typically takes only a few minutes. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are compared to standard reference ranges for healthy individuals. Elevated levels may suggest conditions like multiple myeloma, lymphoma, or other plasma cell disorders. Low levels alone are less commonly significant but may indicate certain immune-related conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Free Kappa Light Chain

Frequently asked questions

What causes elevated free kappa light chains?
Elevated levels are most commonly linked to multiple myeloma, Waldenström macroglobulinemia, or other plasma cell disorders. Rarely, they may appear in conditions like chronic lymphocytic leukemia or certain autoimmune diseases.
What if my results are abnormal?
If your results are elevated, your doctor may recommend further testing, such as bone marrow biopsy, imaging scans, or additional bloodwork. They’ll work with you to determine the next steps based on your symptoms and overall health.
Can diet or medications affect this test?
Some medications (e.g., certain chemotherapy drugs) or kidney disease may influence light chain levels. Fasting may be required before testing, so follow your provider’s instructions to ensure accurate results.
  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