Free Kappa, Lt Chains,S
Test:
361
CPT:
83521
Synonyms
Kappa Free Light Chains, Quantitative, Serum
Kappa:Lambda Free Light Chains Ratio, Quantitative, Serum
Kappa:Lambda Free Light Chains, Quantitative, Serum
Lambda Free Light Chains, Quantitative, Serum
Special Instructions
Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient’s course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only
Expected Turnaround Time
1 – 3 days
Specimen Requirements
Specimen
1 – 3 days
Volume
0.5 mL
Minimum Volume
0.2 mL
Container
Red-top tube or gel-barrier tube
Collection
Sample should be allowed to clot and the serum separated as soon as possible to prevent hemolysis. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions
Refrigerate; samples are stable for 21 days at 2°C to 8°C. For longer storage, freeze at -20°C.
Causes for Rejection
Microbially-contaminated specimen; specimen containing particulate matter; lipemic or hemolyzed specimen
Test Details
Use
Free light chain (FLC) results should be considered under the following categories and investigated appropriately (κ = kappa free light chain; λ = lambda free light chain).
1. Normal samples: Serum κ, λ, and κ:λ are all within the normal ranges. If accompanying serum electrophoretic tests are normal, it is most unlikely that the patient has a monoclonal gammopathy.
2. Abnormal κ:λ ratios: Support the diagnosis of a monoclonal gammopathy and require an appropriate tissue biopsy. Borderline elevated κ:λ ratios occur with renal impairment and may require appropriate renal function tests.
3. Low concentrations of κ, λ, or both: Indicate bone marrow function impairment.
4. Elevated concentrations of both κ and λ with a normal κ:λ ratio: May be due to the following:
• Renal impairment (common)
• Overproduction of polyclonal FLCs from inflammatory conditions (common)
• Biclonal gammopathies of different FLC types (rare)
5. Elevated concentrations of both κ and λ with an abnormal κ:λ ratio: Suggest a combination of monoclonal gammopathy and renal impairment.