Test Id : TLCU
Immunoglobulin Total Light Chains, Urine
Useful For
Suggests clinical disorders or settings where the test may be helpful
Monitoring patients whose urine demonstrates 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
Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| KTLCU | Kappa Total Light Chain, U | No | Yes |
| LTLCU | Lambda Total Light Chain, U | No | Yes |
| KLTRU | Kappa/Lambda TLC Ratio, U | No | Yes |
Method Name
A short description of the method used to perform the test
Nephelometry
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Immunoglobulin Light Chains
Kappa Light Chains
Lambda Light Chains
Light Chains, Kappa and Lambda
Urine Light Chains
Specimen Type
Describes the specimen type validated for testing
Urine
Ordering Guidance
If serum is being submitted on the same patient for FLCS / Immunoglobulin Free Light Chains, Serum; that test should be ordered under a different order number.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Submit only 1 of the following specimens:
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Specimen Type: Random urine
Collection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 5-mL tube
Specimen Volume: 1 mL
Collection Instructions:
1. Collect a random urine specimen.
2. Refrigerate after collection and send refrigerate.
Specimen Type: 24-Hour urine
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 1 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. No additive needed for preservation.
3. Urine may be kept ambient during the collection period but should be refrigerated within 4 hours of collection completion.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Urine Preservative Collection Options
Note: The application of temperature controls must occur within 4 hours of completion of the collection.
| Ambient (No additive) | OK <72 hours |
| Refrigerate (No additive) | Preferred |
| Frozen (No additive) | OK |
| 50% Acetic Acid | No |
| Boric Acid | No |
| Diazolidinyl Urea | No |
| 6M Hydrochloric Acid | No |
| 6M Nitric Acid | No |
| Sodium Carbonate | No |
| Thymol | No |
| Toluene | No |
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.5 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 7 days | |
| Ambient | 72 hours | ||
| Frozen | 20 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Monitoring patients whose urine demonstrates 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
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Immunoglobulin light chains are usually cleared from blood through the renal glomeruli and reabsorbed in the proximal tubules so that urine light-chain concentrations are very low or undetectable. The production of large amounts of monoclonal light chains, however, can overwhelm this reabsorption mechanism. The detection of monoclonal light chains in the urine (Bence Jones proteinuria) has been used as a diagnostic marker for multiple myeloma since the report by Dr. H. Bence Jones in 1847.
Current laboratory procedures employ protein electrophoresis and isotype testing for the identification and characterization of urine monoclonal light chains, which may be present in large enough amounts to also be quantitated as an M-spike on protein electrophoresis. The electrophoretic M-spike is the recommended method of monitoring monoclonal gammopathies, such as multiple myeloma. Monitoring the urine M-spike is especially useful in patients with light-chain multiple myeloma in whom the serum M-spike is very small or absent, but the urine M-spike is large.
Just as quantitative serum immunoglobulins by immunonephelometry are a complement to M-spike quantitation by serum electrophoresis, this quantitative urine light-chain assay may be used to complement urine M-spike quantitation by electrophoresis.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
KAPPA TOTAL LIGHT CHAIN
<0.9 mg/dL
LAMBDA TOTAL LIGHT CHAIN
<0.7 mg/dL
KAPPA/LAMBDA RATIO
0.7-6.2
Interpretation
Provides information to assist in interpretation of the test results
A kappa/lambda (K/L) ratio greater than 6.2 suggests the presence of monoclonal kappa light chains.
A K/L ratio less than 0.7 suggests the presence of monoclonal lambda light chains.
In 24-hour specimens, a greater than 90% increase in concentration suggests progression or relapse; a greater than 90% decrease suggests treatment response.
Increased kappa and/or lambda light chains may be seen in benign (polyclonal) and neoplastic (monoclonal) disorders.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Unlike the electrophoretic M-spike, this immunoassay quantitates both polyclonal and monoclonal light chains and is therefore not sensitive for detecting small monoclonal abnormalities. A normal kappa/lambda (K/L) ratio does not rule out a monoclonal protein, and an abnormal ratio does not identify a monoclonal protein. Urine protein electrophoresis and isotype testing are more sensitive and specific.
The quantitation of urine kappa light chain by immunonephelometry yields results that are approximately 2 times the values from the electrophoresis M-spike. Sequential results should be compared to previous results obtained by the same methodology.
Supportive Data
In a study of 168 urine samples with a monoclonal light chain detected by immunofixation electrophoresis (IFE), there were 20 samples with a normal kappa/lambda (K/L) ratio. These samples had either no M-spike (n=13) or M-spikes <0.5 mg/dL. Conversely, among the 148 cases with an abnormal K/L ratio, there were 12 samples with no M-spike indicating that there is no clear M-spike value at which the K/L ratio identifies monoclonal light chains. In patients with an M-spike, the relationship between the kappa and lambda light-chain quantitation and the size of the M-spike had good correlation (kappa, r[2]=0.94;lambda,r[2]=0.71) and the regression lines had slopes of 2.4 of kappa and 1.1 for lambda.
Interestingly, there was a single case in which the K/L ratio was 24 and the free light-chain K/L ratio was 58, but the IFE showed polyclonal light chains. The patient was post-transplant for a kappa light-chain multiple myeloma and presumably had multiple forms of a monoclonal kappa light chain that migrated in a smear and was a false-negative by IFE.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Kumar S, Paiva B, Anderson KC, et al. International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma. Lancet Oncol. 2016;17(8):e328-e346
2. Leung N, Barnidge DR, Hutchison CA. Laboratory testing in monoclonal gammopathy of renal significance (MGRS). Clin Chem Lab Med. 2016;54(6):929-937
3. Willrich MA, Katzmann JA. Laboratory testing requirements for diagnosis and follow-up of multiple myeloma and related plasma cell dyscrasias. Clin Chem Lab Med. 2016;54(6):907-919
4. Rajkumar SV, Kyle RA. Multiple myeloma: diagnosis and treatment. Mayo Clin Proc. 2005;80(10):1371-1382
Method Description
Describes how the test is performed and provides a method-specific reference
In this Siemens Nephelometer II method, the light scattered by the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.
A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light emitting diode (LED), which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is yet formed. An antigen-antibody complex is formed in the final measurement.
The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Instruction manual: Siemens Nephelometer II. Siemens, Inc; Version 2.4, 07/2019; Addendum to the Instruction Manual 2.3, 08/2017)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
83883 x 2
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| TLCU | Immunoglobulin Total Light Chains,U | 44792-0 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| KLTRU | Kappa/Lambda TLC Ratio, U | 33559-6 |
| KTLCU | Kappa Total Light Chain, U | 27365-6 |
| LTLCU | Lambda Total Light Chain, U | 27394-6 |