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Test Code FHLCA Immunoglobulin A (IgA) Heavy and Light Chain (HLC) Pairs, Kappa and Lambda with Ratio


Specimen Required


Specimen Type: Serum

Container/Tube:  Red top or SST

Specimen Volume: 0.75 mL

 

Collection Instructions: Draw blood in a plain red-top tube, serum gel tube(s) is also acceptable. Separate serum immediately after coagulation (30 minutes) to prevent hemolysis. Send 0.75 mL of serum refrigerated in a plastic vial.

 

NOTE: Patient should be fasting for eight hours to avoid lipemic sample interference.


Secondary ID

75550

Useful For

For the quantitative measurement of human IgA heavy chain and light chain intact immunoglobulin in serum. The result can be used when monitoring previously diagnosed IgA multiple myeloma patients and is used in conjunction with other clinical and laboratory findings.

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 IgA proteins that are difficult to quantitate using serum protein electrophoresis alone.

3. Providing a more specific quantitation of the monoclonal protein than total IgA measurements alone.

Reporting Name

IgA Heavy Light Chains (HLC), S

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reject Due To

Hemolysis Mild reject; Gross reject
Lipemia Mild reject; Gross reject
Icterus NA
Other Microbially-contaminated specimen; specimen containing particulate matter

Clinical Information

Elevated serum concentrations of monoclonal protein are indicative of an underlying abnormality, such as monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma, and other lymphoproliferative disorders. International guidelines recommend serum protein electrophoresis (SPE) densitometry to be performed to quantify monoclonal proteins. However, monoclonal IgA proteins can often be obscured by other proteins in the Beta region of a SPE gel, making quantification inaccurate.

Nephelometry can be used in these instances to measure total IgA, but this will include nontumor immunoglobulin, and measurement of either IgA Kappa or IgA Lambda may give a more accurate representation of tumor production. Furthermore, measurement of both IgA Kappa and IgA Lambda, calculation of the IgA Kappa:IgA Lambda ratio and comparison with values found in normal subjects can give a more sensitive indication of clonality. Use of the IgA Kappa:IgA Lambda ratio will also compensate for any changes in plasma volume.

Reference Values

IgA Kappa (g/L): 0.48-2.82

IgA Lambda (g/L): 0.36-1.98

IgA Kappa:IgA Lambda ratio: 0.80-2.04

Interpretation

An elevated IgA heavy and light chain (HLC) pair ratio suggests a clonal proliferation of an IgA Kappa clone of plasma cells.

A low IgA HLC pair ratio suggests a clonal proliferation of an IgA Lambda clone of plasma cells.

Day(s) Performed

Tuesday, Friday

Performing Laboratory

LabCorp Burlington

CPT Code Information

83883 x 2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FHLCA IgA Heavy Light Chains (HLC), S 74773-3

 

Result ID Test Result Name Result LOINC Value
Z5616 IgA Kappa, S 74864-0
Z5617 IgA Lambda, S 74865-7
Z5618 IgA K/L HLC Ratio 74869-9

Method Name

Turbidimetric