Test Code LAB735 Immunoglobulin Free Light Chains, Serum Kappa/Lambda
Additional Codes
CPT Code: 83883 x 2
Useful For
Monitoring patients with monoclonal light chain diseases but no M-spike on protein electrophoresis.
Performing Laboratory
TidalHealth Peninsula Regional - Core Laboratory: Chemistry
Specimen Requirements
Serum collected with or without gel barrier
Draw blood in a red plain, gold, or tiger-top serum gel tube. Serum needs to be seperated from cells within 2 hours. Centrifuge and send 1 mL of serum refrigerated at 2 - 8° C in original vacutainer. If not in a gel barrier tube, seperate serum into an aliquot tube to remove from cells.
Reference Values
KAPPA-FREE LIGHT CHAINS
<20.73 mg/L
LAMBDA-FREE LIGHT CHAINS
4.23-27.69 mg/L
KAPPA/LAMBDA FLC RATIO
0.22 – 0.174
Methodology
Testing performed by a latex particle enhanced immunoturbidimetric assay for the quantitative determination on the Roche Cobas Pro. The concentration of serum free light chains in specimens determined with assays from different manufacturers can vary due to differences in assay methods and reagent specificity. Values obtained with different assay methods cannot be used interchangeably. If, while monitoring a patient, the assay method is changed, additional sequential testing should be carried out to confirm baseline values.