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Test ID BCGRV Immunoglobulin Gene Rearrangement, Varies

Useful For

Determining whether a B-cell or plasma cell population is polyclonal or monoclonal

 

Identifying neoplastic cells as having B-cell or plasma cell differentiation

 

Monitoring for a persistent neoplasm by detecting an immunoglobulin gene rearrangement profile similar to that from a previous neoplastic specimen

Method Name

Genomic DNA Extracted Followed by Polymerase Chain Reaction (PCR)

(PCR is used pursuant to a license agreement with Roche Molecular Systems, Inc. and InvivoScribe Technologies)

Reporting Name

Immunoglobulin Gene Rearrange, V

Specimen Type

Varies

Forms:

1. Hematopathology Patient Information Sheet (Supply T676) in Special Instructions

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request Form (T726) with the specimen

(http://www.mayomedicallaboratories.com/it-mmfiles/hematopathology-request-form.pdf)

 

Body fluid or spinal fluid must arrive within 96 hours of collection.

 

Submit only 1 of the following specimens:

 

Specimen Type: Body fluid

Container/Tube: Sterile container

Specimen Volume: At least 5 mL

Collection Instructions:

1. If the volume is large, pellet cells prior to sending.

2. Send less volume at ambient temperature or as a frozen cell pellet.

Specimen Stability Information:

Body Fluid: Ambient/Refrigerated/Frozen

Cell Pellet: Frozen

 

Specimen Type: Paraffin-embedded bone marrow aspirate clot

Container/Tube: Paraffin block

Specimen Stability Information: Ambient/Refrigerated

 

Specimen Type: Frozen tissue

Container/Tube: Plastic container

Specimen Volume: 100 mg

Collection Instructions: Freeze tissue within 1 hour of collection.

Specimen Stability Information: Frozen

 

Specimen Type: Paraffin-embedded tissue

Container/Tube: Paraffin block

Specimen Stability Information: Ambient/Refrigerated

 

Specimen Type: Spinal fluid

Container/Tube: Sterile vial

Specimen Volume: 5-10 mL

Specimen Stability Information: Ambient/Refrigerated

 

Specimen Type: Extracted DNA from blood or bone marrow

Container/Tube: 1.5- to 2-mL tube with indication of volume and concentration of DNA

Specimen Volume: Entire specimen

Collection Instructions: Label specimen as extracted DNA from blood or bone marrow

Specimen Stability Information: Refrigerated/Ambient

Specimen Minimum Volume

Body Fluid or Spinal Fluid: 1 mL/Tissue: 50 mg/Extracted DNA from Blood or Bone Marrow: 50 microliter at 20 ng/microliter

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies

Clinical Information

The immunoglobulin (Ig) genes (heavy, kappa, and lambda) are comprised of numerous, discontinuous coding segments. As B cells develop, the segments are rearranged such that each mature B cell and plasma cell has a unique rearrangement profile. Other cell types usually retain the nonrearranged gene structures. Clonal expansion of any B cell or plasma cell will result in a population of cells that all contain an identical Ig gene rearrangement profile.

 

Reactive B-cell or plasma cell expansions are polyclonal, with each clone containing relatively few cells and no single clone predominating. Conversely, neoplastic clones are generally large such that the clonal cells are the predominant B cells or plasma cells present.

 

In the appropriate clinical and pathologic setting, detection of a prominent Ig gene rearrangement profile may be equated to the presence of a neoplastic B-cell or plasma cell clone.

Reference Values

An interpretive report will be provided.

Cautions

This test is neither 100% sensitive nor 100% specific.

 

False-negative results may occur if the immunoglobulin (Ig) gene has numerous point mutations introduced during expansion in a follicle center (somatic hypermutation) such that none of the PCR primers will bind. False-negatives will also occur if the clonal cells have not rearranged the Ig genes being evaluated or are present below the sensitivity level of the assay (sensitivity is quite variable but the assay requires that at least 1%-5% of the nucleated cells present be clonal). False-positive results are rare but may occur if a predominant clone (or small number of clones) is produced or sampled from a polyclonal expansion.

 

The test does not provide information regarding:

-The differentiation of the clonal cell population (neoplastic cells other than B cells or plasma cells may occasionally have Ig gene rearrangements)

-Whether a prominent clone is physiologic or neoplastic

Day(s) Performed

Monday through Friday

Report Available

7 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed using an analyte specific reagent. 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 U.S. Food and Drug Administration.

CPT Code Information

81261-IGH (Immunoglobulin heavy chain locus) (eg, leukemias and lymphomas B-cell), gene rearrangement analysis to detect abnormal clonal populations; amplified methodology (eg. polymerase chain reaction)

81264-IGK (Immunoglobulin kappa light chain locus) (eg, leukemia and lymphoma, B-cell) gene rearrangement analysis, evaluation to detect abnormal clonal populations

NY State Approved

Yes