Kappa/Lambda Light Chain Free Serum

Test Code

KAPPA/LAMBDA LIGHT-CHAIN FREE SERUM

Preferred Specimen

Gold Top Tube

Minimum Volume

2 mL

Transport Temperature

Refrigerate

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Reject if 3+ or 4+ lipemia/icterus/hemolysis

Methodology
Optilite/Colorimetric

Setup Schedule

M-F

Report Available

TAT 2 - 5 days

Reference Range

TEST	RANGE
Free Kappa	3.30-22.50 mg/L
Free Lambda	5.71-30.50 mg/L
Ratio	0.26 to 1.65
	Patients with chronic kidney disease (CKD) commonly experience increases in both the individual kappa and lambda free light chains and the K/L light chain ratio. As eGFR declines, kappa raises faster than lambda, hence an increase in the K/L ratio is observed. The following are proposed normal reference ranges for patients with CKD: eGFR K/L Ref Range: 45-59 0.46-2.62 30-44 0.48-3.38 <30 0.54-3.30 Ref. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9470548/

Clinical Significance

Elevated serum levels of monoclonal free light chains with abnormal free kappa/free lambda ratios is associated with malignant plasma cell disorders including multiple myeloma, nonsecretory multiple myeloma, light chain disease, and primary amyloidosis. This assay may also be useful in monitoring the treatment of patients previously diagnosed with multiple myeloma.

High or low ratios are suggestive of monoclonal gammopathies.

Performing Laboratory
Test performed in the West Roxbury Immunology Lab
Contact: Cassandra Mota, 857-203-5941

Last Updated: May 1, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.