Serum/plasma free light chain kappa to lambda ratio (immunoassay)
This test measures the balance between two types of light chains (kappa and lambda) found in your blood, which can help diagnose conditions affecting plasma cells, such as multiple myeloma or other monoclonal gammopathies.
["Assessing light chain imbalance may help identify hidden blood disorders."]
Key facts at a glance
- LOINC
- 47755-4
- Short code
- GH sp10 p chal SerPl-aCnc
- Synonyms
- GH sp10 p chal SerPl-aCnc
- Category
- chemistry
- 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
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms like fatigue, unexplained weight loss, frequent infections, or kidney problems. It’s also used to monitor conditions like multiple myeloma, lymphoma, or other plasma cell disorders that affect light chains in the blood.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The test is quick and typically done in a lab setting.
What the Results Mean
A normal result suggests balanced light chain levels, while an abnormal ratio may indicate an excess of either kappa or lambda chains, which can signal underlying conditions requiring further evaluation.
Common Conditions Monitored
This test helps diagnose or track conditions like multiple myeloma, monoclonal gammopathy of undetermined significance (MGUS), or other plasma cell disorders. It’s also used in patients with kidney disease or autoimmune disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: An elevated or skewed light chain ratio often points to clonal plasma cell disorders, where abnormal cells produce excessive light chains. These findings may prompt additional testing, such as bone marrow biopsy or further bloodwork, to determine the cause and guide treatment decisions.
Short name
Free Light Chain Ratio
Frequently asked questions
What causes an abnormal light chain ratio?
How often should this test be repeated?
Can diet or medications affect this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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