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Immunoglobulin Heavy Chain Gene Rearrangement by PCR

B-cell Gene Rearrangement, Immunoglobulin Gene Rearrangement, IGH Gene Rearrangement, B-cell Clonality, B-cell PCR, Immunoglobulin Heavy Chain (IGH) Gene Rearrangement by PCR, Lymphocyte Gene Rearrangement, Gene Tests

Test Codes

EPIC: LAB1231620, Beaker: MBCLG

Department

Molecular Pathology

Specimen Collection Criteria

Collect: One of the following specimen types, as described below:

1. Blood: 5.0 mL whole blood in Lavender-top EDTA tubes. Invert several times to mix blood. (Minimum: 3.0 mL)
2. Bone Marrow: 2.0 mL bone marrow in a Lavender-top EDTA tube. Invert several times to mix bone marrow.
3. Spinal Fluid: 10 mL spinal fluid in the original sterile collection container. An attempt will be made to extract sufficient DNA from any volume submitted. (Minimum: 5.0 mL)
4. Solid Tissue:
   • Paraffin-Embedded Tissue: A paraffin block must be submitted. (Slides or paraffin shavings are not acceptable.) Submit a 10% formalin-fixed, paraffin-embedded block with corresponding H&E slide. Average tissue size: 5.0 mm².

• All specimen types should be sent to the Laboratory immediately for processing.
• The specimen must be accompanied by a completed requisition and must contain the patient name, hospital and visit number, date of birth, collection date, ordering physician, and source of specimen.

Physician Office/Draw Specimen Preparation

Maintain whole blood, bone marrow, and spinal fluid at room temperature (20-26°C or 68-78.8°F) or refrigerated (preferred) (2-8°C or 36-46°F) prior to transport. Maintain paraffin-embedded tissue at room temperature (20-26°C or 68-78.8°F).

Preparation for Courier Transport

Transport: Paraffin-embedded tissue at room temperature (20-26°C or 68-78.8°F), blood, bone marrow, or spinal fluid, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

• Anticoagulants other than EDTA.
• Clotted peripheral blood or bone marrow.
• Centrifuged specimens
• Fresh or frozen tissue specimens.
• Tissue decalcified with agents other than Mol Decal (EDTA).
• Fixatives other than 10% neutral buffered formalin (e.g., zinc formalin)
• Improper labeling or inadequate information. 
• Specimens not collected and processed as indicated.
• Less than 10 percent tumor cellularity, at discretion of medical director.
• Poor quality and/or quantity of extracted genomic DNA.

Client will be notified of any cancellation of testing.

Inpatient Specimen Preparation

Specimens at Royal Oak may be sent to the Surgical Pathology tube station, #201. In-house specimens are also picked up by a Surgical Pathology assistant every hour on the hour.

In-Lab Processing

Maintain whole blood, bone marrow, and spinal fluid refrigerated (2-8°C or 36-46°F), or paraffin-embedded tissue at room temperature (20-26°C or 68-78.8°F) until testing.

Storage

Specimen Stability for Testing:

Blood, Bone Marrow, and Spinal Fluid
Room Temperature (20-26°C or 68-78.8°F): 72 hours
Refrigerated (2-8°C or 36-46°F): 72 hours
Frozen (-20°C/-4°F or below): Unacceptable

Paraffin-Embedded Tissue
Room Temperature (20-26°C or 68-78.8°F): Indefinitely
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

Royal Oak Clinical Molecular Pathology Laboratory

Performed

Monday – Friday.
Results available in 10 business days.

Reference Range

No monoclonal IGH gene rearrangement identified.

Test Methodology

DNA extraction followed by PCR amplification and analysis of the products by capillary electrophoresis.

Interpretation

An interpretive report will be provided.

Clinical Utility

Detection of a prominent IGH gene rearrangement is supportive of a neoplastic B-cell process. However, the results must always be interpreted in the context of other clinicopathologic information as non-neoplastic conditions (e.g., infectious and autoimmune processes) may yield a monoclonal IGH gene rearrangement.

Limitations:

1. This test is neither 100% sensitive nor 100% specific.
2. False-positive results are not uncommonly encountered with Polymerase Chain Reaction (PCR)-based assays. This is usually because the kinetics of end-point, competitive PCR are such that the true proportions of rearrangements present may not be maintained during amplification.
3. False-negative PCR results may occur if there is failure of primer binding or if the rearrangement involves a segment that is not bound by the primers used in the assay. False-negative results will also occur if the clonal cells have not rearranged the IGH genes being evaluated or are present below the sensitivity of the assay (approximately 1-5% of abnormal nucleated cells).
4. This assay cannot determine whether a clonal rearrangement is physiologic or neoplastic.
5. This assay cannot be utilized to definitively assign lineage (i.e., B-cell vs. T-cell) to a neoplastic process.

Reference

1. Coad JE, et al. Molecular Assessment of Clonality in Lymphoproliferative Disorders: I. Immunoglobulin Gene Rearrangements. Mol Diagnosis 1996 Mar;1(4):335-55.

CPT Codes

81261

Contacts

Last Updated

8/19/2024