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For hours, walk-ins and appointments.Immunoglobulin M (IgM) Heavy and Light Chain (HLC) Pairs, κ and λ With Ratio
CPT:
83521(x2)
Synonyms
- Hevylite IgM
- HLC IgM
- IgM κ:λ HLC Ratio
Expected Turnaround Time
4 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
For more information, please view the literature below.
Specimen Requirements
Specimen
Serum
Volume
0.75 mL
Minimum Volume
0.5 mL
Container
Red-top tube or gel-barrier tube
Collection
Separate serum immediately after coagulation (30 minutes) to prevent hemolysis.
Storage Instructions
Refrigerate.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 7 days |
Refrigerated | 7 days |
Frozen | 7 days |
Freeze/thaw cycles | Stable x2 |
Causes for Rejection
Microbially-contaminated specimen; specimen containing particulate matter; lipemic or hemolyzed specimen
Test Details
Use
For the quantitative measurement of human IgM heavy chain and light chain intact immunoglobulin in serum. The test result is to be used with previously diagnosed Waldenström's macroglobulinemia in conjunction with other clinical and laboratory findings. This assay has not been established for the diagnosis, monitoring, and prognosis of Waldenström's macroglobulinemia.
Heavy and light chain pair quantitation may be useful for:
1. Distinguishing between broadly migrating monoclonal proteins and restricted polyclonal immunoglobulin patterns on serum protein electrophoresis.
2. Quantitating monoclonal IgM proteins that are difficult to quantitate using serum protein electrophoresis alone.
3. Providing a more specific quantitation of the monoclonal protein than total IgM measurements alone.
Limitations
Decisions on patient evaluation and management must not be given on the basis of IgM κ, IgM λ, or IgM κ:IgM λ ratio measurements alone. Clinical history and other laboratory findings must be taken into account.
Heavy and light chain (HLC) quantitation should be used as a complementary method to serum protein electrophoresis.
The effect of therapeutic drugs on the measurement of IgM κ and IgM λ by this assay has not been evaluated.
Small increases in the concentrations of monoclonal IgM proteins may not result in an altered HLC pair ratio.
For initial detection of monoclonal proteins, see:
• Immunofixation (IFE), Serum and Protein Electrophoresis, Serum [001495]
• Immunofixation (IFE) and Protein Electrophoresis, 24-Hour Urine [003467]
Methodology
Turbidimetric
Reference Interval
• IgM κ (g/L): 0.29−1.82
• IgM λ (g/L): 0.17−0.94
• IgM κ:IgM λ ratio: 0.96−2.30
An elevated IgM heavy and light chain (HLC) pair ratio suggests a clonal proliferation of an IgM κ clone of plasma cells.
A low IgM HLC pair ratio suggests a clonal proliferation of an IgM λ clone of plasma cells.
Additional Information
Elevated serum concentrations of monoclonal protein are indicative of an underlying abnormality, such as monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma, Waldenström's macroglobulinemia and other lymphoproliferative disorders. Serum protein electrophoresis (SPE) densitometry is recommended to quantify monoclonal proteins.1
Nephelometry can also be used in these instances to measure total IgM, but this will include nontumor immunoglobulin, and measurement of either IgM κ or IgM λ may provide additional information regarding tumor production.
Footnotes
1. Kyle RA, Rajkumar SV. Monoclonal gammopathies of undetermined significance: A review.Immunol Rev. 2003 Aug; 194:112-139. 12846812
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 123560 | IgM Heavy Light Chains(HLC), S | 123537 | IgM Kappa, S | g/L | 74866-5 | |
| 123560 | IgM Heavy Light Chains(HLC), S | 123538 | IgM Lambda, S | g/L | 74867-3 | |
| 123560 | IgM Heavy Light Chains(HLC), S | 123539 | IgM K/L HLC Ratio | Ratio | 74870-7 |
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