Total Light Chains, Urine (TLCU)

Test Code: TLCUSO

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Synonyms/Keywords

Ref Lab Code:87934, Immunoglobulin Light Chains, Kappa Light Chains, Lambda Light Chains, Light Chains, Kappa and Lambda, Urine Light Chains

Useful For

Monitoring patients whose urines demonstrate large M-spikes

Confirming the quantitation of specimens that show M-spikes by electrophoresis

Detecting urine monoclonal proteins and identification of specimens that need urine protein electrophoresis

Specimen Requirements

Specimen Type	Preferred Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)
Submit only 1 of the following specimens:
Urine(24 hours)	Plastic, 10-mL urine tube	1.0 mL	0.5 mL
Urine (random)	Plastic, 10-mL urine tube	1.0 mL	0.5 mL

Collection Processing Instructions

Urine Preservative Cross-Reference Information

Specimen Stability Information

Specimen Type	Temperature	Time
Urine	Refrigerated (preferred)	7 days
	Frozen	20 days
	Ambient	72 hours

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Mayo Medical Laboratories	Monday through Saturday	Same day/1 day	Nephelometry

Reference Lab

Mayo Clinic Laboratories

Test Information

If serum is being submitted on the same patient for FLCP/84190 Immunoglobulin Free Light Chains, Serum; order that test under a different order.

Reference Range Information

Kappa Total Light Chain: <0.68 mg/dL
Lambda Total Light Chain: <0.40 mg/dL
Kappa / Lambda Ratio: 0.7-6.2

Interpretation

A kappa/lambda (K/L) ratio >6.2 suggests the presence of monoclonal kappa light chains.

A K/L ratio <0.7 suggests the presence of monoclonal lambda light chains.

In 24-hour specimens, a >90% increase in concentration suggests progression or relapse; a >90% decrease suggests treatment response.

Increased kappa and/or lambda light chains may be seen in benign (polyclonal) and neoplastic (monoclonal) disorders.

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
83883		2

Synonyms/Keywords

Ref Lab Code:87934, Immunoglobulin Light Chains, Kappa Light Chains, Lambda Light Chains, Light Chains, Kappa and Lambda, Urine Light Chains

Ordering Applications

Ordering Application	Description

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.

Specimen Requirements

Specimen Type	Preferred Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)
Submit only 1 of the following specimens:
Urine(24 hours)	Plastic, 10-mL urine tube	1.0 mL	0.5 mL
Urine (random)	Plastic, 10-mL urine tube	1.0 mL	0.5 mL

Collection Processing