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HelpTest Code FLCS Immunoglobulin Free Light Chains, Serum
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Useful For
Monitoring serum from patients with monoclonal light chain diseases without a M-spike on protein electrophoresis
May be useful as a diagnostic test in patients in whom there is a suspicion of primary systemic amyloidosis, light chain deposition disease, or non-secretory myeloma
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| KFLCS | Kappa Free Light Chain, S | No | Yes |
| LFLCS | Lambda Free Light Chain, S | No | Yes |
| KLRS | Kappa/Lambda FLC Ratio | No | Yes |
Testing Algorithm
The following algorithms are available:
Special Instructions
Reporting Name
Immunoglobulin Free Light Chains, SSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
KAPPA-FREE LIGHT CHAIN
0.33-1.94 mg/dL
LAMBDA-FREE LIGHT CHAIN
0.57-2.63 mg/dL
KAPPA/LAMBDA FLC RATIO
0.26-1.65
Supportive Data
Studies at Mayo Clinic have shown that in some patients with urine monoclonal light chains and negative serum immunofixation (IF), the free light chain (FLC) assay can identify monoclonal FLC in the serum. These studies support the increased sensitivity of the nephelometric FLC assay. In a series of patients with primary systemic amyloid treated by stem cell transplantation, the quantitation and monitoring of FLC predicted organ response (eg, disease course).
Specimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
83521 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FLCS | Immunoglobulin Free Light Chains, S | 104533-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LFLCS | Lambda Free Light Chain, S | 33944-0 |
| KLRS | Kappa/Lambda FLC Ratio | 104546-7 |
| KFLCS | Kappa Free Light Chain, S | 104544-2 |
Day(s) Performed
Monday through Friday
Report Available
Same day/1 to 2 daysForms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Hematopathology/Cytogenetics Test Request (T726)
-Renal Diagnostics Test Request (T830)