B Cell Clonality (IGH Gene Rearrangement)

Test Overview

Test Methodology

Polymerase Chain Reaction (PCR) followed by capillary electrophoresis

Test Usage

Lymphoproliferative disorders are often characterized by an expansion of the lymphocyte populations. The distinction of benign from malignant proliferations can be accomplished by the integration of clinical, morphologic, immunophenotypic, and molecular genetic studies. With regard to molecular studies, an evaluation for the presence of a B-cell population with monoclonal rearrangement of the immunoglobulin gene can provide adjunctive information to support a final diagnosis. These studies are based on the premise that all cells of a malignant lymphoid population have a common, clonal origin and therefore are expected to contain immunoglobulin genes rearranged in exactly the same configuration. Thus, demonstration of monoclonality is indicative of the presence of a monoclonal B-cell population and polyclonality is indicative of a polyclonal population. The clinical implications of these results must be interpreted in the context of the individual patient’s clinicopathologic presentation.

Reference Range *

Interpretive report provided.

Test Limitations

A negative result does not exclude a B cell neoplasm. This assay is sensitive to a level of approximately 15% clonal lymphocytes. Factors such as uncommon rearrangements and somatic hypermutation may also result in false negative results. Higher sensitivity may be obtained by ordering both IGHand IGK gene rearrangement studies. A positive result is not synonymous with neoplasia or specific to neoplasms of B cell origin. Clinicopathologic correlation with gene rearrangement results is required. Insufficient cellular content may result in an inadequate result.

Test Details

Days Set Up

Monday - Friday

Analytic Time

3 - 10 days

Soft Order Code

GRB

MiChart Code

B Cell Clonality- IGH Gene Rearrangement

Synonyms

IGH+GR by PCR
GRBPCR
Gene Rearrangement, B Cell
IGH Gene Rearrangement
Gene Rearrangement, B-Cell
B Cell Gene Rearrangement
MLABEL
GRB
B CELL GENE REARR. BY PCR
B-Cell Clonality

Laboratory

Molecular Diagnostics

Section

Molecular Diagnostics

Specimen Requirements

Collection Instructions

Collect blood or bone marrow in a lavender top tube. Refrigerate and send intact blood or bone marrow specimen within 48 hours of collection. Fresh tissue (preferably 0.5cm3, sent in RPMI) and fresh aspirates or body fluids are acceptable. Refrigerate and send, preferably within 24 hours. Frozen tissue specimens – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. Fresh cell suspensions in RPMI should be refrigerated and sent, preferably within 48 hours. Frozen cell suspensions – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. For formalin-fixed, paraffin-embedded tissue, a tissue block is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature.

Alternate Specimen

The preferred specimen is whole blood or bone marrow collected in EDTA (lavender top). However, ACD (yellow top) and heparin (green top) may also be accepted. Previously extracted DNA may also be accepted.

Normal Volume

5 mL EDTA (lavender) whole blood; 3 mL EDTA (lavender) bone marrow; Fresh/frozen tissue and fresh aspirates or body fluids; Fresh/frozen cells in RPMI; Formalin-fixed, paraffin-embedded tissue.
Extracted DNA is also acceptable if extracted in a CLIA certified laboratory.

Additional Information

By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

Billing

CPT Code

81261

Fee Code

21648

Pro Fee CPT

G0452-26

Prior Authorization

The Prior Authorization form is required for this test. Click here to download the PDF.

NY State Approved

No