Immunoglobulin Kappa (IGK) Clonality Detection  by PCR and Capillary Electrophoresis

CPT Code(s)

81264, G0452

Synonym(s)

IG-Kappa Gene Clonality Detection, B-cell Receptor IGK Gene Rearrangement

Performed

Molecular Diagnostics Laboratory

Clinical Indication and Relevance

The assay is useful to assist with the diagnosis of B-cell malignancies. The assay can also be used to detect minimal residual disease in follow-up samples.

Methodology

The assay is performed on isolated DNA with BIOMED-2 primers amplifying the VK, JK as well as intragenic and Kde region of the IG kappa (IGK) gene. The gene rearrangements are detected by analyzing the PCR products using capillary gel electrophoresis. The assay sensitivity for detection of clonal B-cell populations is 10% of lymphocytes.

Minimum Specimen Requirements

Collect

  • Peripheral blood (PB): 3-5 mL, in purple top (sodium EDTA) tube.
  • Bone marrow (BM): 1-3 mL, drawn into a syringe containing anticoagulant and then
    delivered in purple top tube (EDTA).
  • Fresh or frozen tissue: fresh tissue should be obtained in a sterile manner, and a minimum
    3 mm3
    of tissue is required. Fresh tissue should be placed in culture medium for transport
    or snap frozen (see transport section below).
  • Formalin-fixed, paraffin-embedded (FFPE) tissue blocks: send tissue block to the lab, or
    contact lab for instructions regarding cutting paraffin sections for molecular studies.

 

Transport

  • PB or BM sample: Deliver immediately at 2-8°C (wet ice or cold packs). Do not freeze.
  • Fresh tissue samples should be delivered at room temperature in RPMI culture medium within 3 hours of collection, or snap frozen in liquid nitrogen at -70°C and packed in
    dry ice for delivery. Please do not allow frozen tissues to thaw.
  • Formalin-fixed paraffin embedded (FFPE) tissue blocks and slides can be delivered at controlled temperatures, not to exceed 30C.

 

Stability
PB or BM samples: ambient – 1 hour; refrigerated – 48 hours.

 

Unacceptable Samples

  • Serum or plasma; frozen PB or BM; clotted blood; severely hemolyzed samples
  • Paraffin tissue fixed in Zenker’s, B5, or Bouin’s fixatives
  • Bone marrow biopsy decalcified in formic acid

Turnaround time

Five to seven working days

View Requisition Sheet