B-CELL CLONALITY (IGH, IGK)

Container Type: Lavender top (EDTA); paraffin embedded tissue and/or slides.
Specimen Type: Whole blood, bone marrow; formalin fixed paraffin embedded tissue.
Alternate Specimens: ACD or sodium citrate whole blood (lavender, yellow, or blue top tube).
Preferred Volume: 5 mL whole blood, 1 mL bone marrow; 1 paraffin embedded tissue block or 6 unstained 7-micron slides with an additional H&E stained slide containing at least 50% tumor cells.
Minimum Volume: 3 mL whole blood, 0.5 mL bone marrow; 1 paraffin embedded tissue block or 4 unstained 7-micron slides with an additional H&E stained slide containing at least 20% tumor cells
Whole blood bone marrow: Submit original unopened tube only.
FFPE: Prepare H&E slide if submitting unstained 7-micron slides.

During normal B-cell development and maturation, the immunoglobulin (Ig) heavy-and light-chain (Kappa and Lambda) genes undergo a series of rearrangements to produce a unique antigen receptor with specificity to a discrete antigen. In a healthy person, B-cell development results in a spectrum of mature B-cells that can respond to essentially any antigen encountered by the individual. In B-cell lymphoproliferative disorders, the neoplastic B-cell population shares the same Ig rearrangement pattern and serves as a marker for monoclonality that can be detected by PCR and capillary electrophoresis. In typical reactive populations, no single rearrangement predominates, yielding a detectable polyclonal pattern. Therefore, a prominent Ig gene rearrangement profile (IGH and/or IGK in this assay) is suggestive for lymphoid malignancy in the appropriate clinical and pathologic setting. Detection of the same profile could be used for monitoring a patient with persistent neoplasm.

Surgical Pathology Report

Whole blood, bone marrow: Store and transport at room temperature or refrigerated if delay of more than 72 hours. Indicate source. FFPE: Transport paraffin embedded, formalin fixed tissue block, or slides at 20-25C. Protect paraffin block from excessive heat. Ship in cooled container during summer months. Include surgical pathology report.

Whole blood in sodium heparin, serum/plasma, grossly hemolyzed, frozen whole blood or bone marrow, specimens in leaky containers or over 5 days old and samples not received in the original unopened collection tubes. No tumor in tissue. Specimens fixed/processed in alternative fixatives (alcohol, Prefer®)

The detection of clonality does not always imply the presence of a malignancy. Some clinically benign proliferations could have a clonal origin (e.g. benign monoclonal gammopathies). False-negative results might be possible due to improper primer annealing.