Kappa-Lambda Quant Free Light Chain Ratio, Blood

Label Mnemonic:	KLFQT
Epic code:	LAB7454
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	83521 x2

Specimen(s):

Blood

Collection Medium:

Pink top tube 6 mL (K2-EDTA)

Minimum:

Preferred Minimum: 3 mL whole blood

Rejection Criteria:

Plasma separator tube

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

Lambda Quantitative Free Light Chains   5.7 - 26.3 mg/L 
Kappa Quantitative Free Light Chains    3.3 - 19.4 mg/L 
Kappa/Lambda Free Light Chain Ratio     0.26 - 1.65

Comments:

Elevated absolute concentrations of both kappa and lambda (K/L) free light chains as well as K/L ratio may occur due to decreased renal function (see reference below) or polyclonal hypergammaglobulinemia. Results should be interpreted in conjunction with clinical history, physical examination, and other diagnostic data. This assay is highly sensitive to increasing concentrations of monoclonal free kappa or free lambda light chains in the serum of patients with evolving or relapsing myelomas.

References:

Long TE et al. Defining new reference intervals for serum free light chains in individuals with chronic kidney disease: Results of the iStopMM study. Blood Cancer Journal 12(9): 133, 2022. doi: 10.1038/s41408-022-00732-3.

Methodology:

Turbidimetric

Sample Processing:

Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection.
Separate plasma into screw-capped plastic vial.
Do not send primary tube if all plasma has been transferred to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.

Sample Storage:

Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).

Transport Instructions:

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.