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Test Code FLCS Immunoglobulin Free Light Chains, Serum

Additional Codes

CNE Order Code: F Kappa/Lambda


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:

-Amyloidosis: Laboratory Approach to Diagnosis

-Multiple Myeloma: Laboratory Screening

Method Name

Turbidimetry

Reporting Name

Immunoglobulin Free Light Chains, S

Specimen Type

Serum

Specimen 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

Interpretation

The specificity of this assay for detection of monoclonal light chains relies on the ratio of free kappa and lambda (K/L) light chains. Once an abnormal free light chain (FLC) K/L ratio has been demonstrated and a diagnosis has been made, the quantitation of the monoclonal light chain is useful for monitoring disease activity.

 

Changes in FLC quantitation reflect changes in the size of the monoclonal plasma cell population. Our experience to date is limited, but changes of more than 25% or trending of multiple specimens are needed to conclude biological significance.

Performing 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 days

Forms

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)