Leukemia Immunophenotyping, by Flow Cytometry

Leukemia Immunophenotyping, by Flow Cytometry

Alternate Test Name

CLL Panel by Flow Cytometry

Epic Mnemonic
Sunquest Mnemonic

LAB2112
LKIMB

Category

Sendouts

Methodology

Flow Cytometry

Test Performance Schedule

Monday - Saturday

Result Availability

3 -5 days

Bone Marrow

Container/Tube: Green top (Sodium Heparin) or Lavender top (EDTA)
Pref. Vol.: 2 – 3 mL
Min. Vol.: 0.5 mL
Collection Instructions: Collected by physician
Transportation Instructions: Room temperature

Whole Blood

Container/Tube: Green top (Sodium Heparin) or Lavender top (EDTA)
Pref. Vol.: 5 - 7 mL
Min. Vol.: 0.5 mL
Collection Instructions:
• Routine Venipuncture
• Immediately after collection, gently invert tube 5-10 times
• Do not centrifuge
• Do not remove plasma from cells
Transportation Instructions: Room temperature

Other specimen sources (CSF, tissues, fluids, FNA, biospies)

Contact the laboratory

Stability

• Room temperature (bone marrow/whole blood): 48 hrs
• Refrigerated (other specimen sources): 48 hrs
• Frozen: Unacceptable
• Flow cytometry: Specimens >48 hrs will still be run and reported

Causes for Rejection

• Not collected in appropriate containers
• Hemolyzed
• Clotted
• Refrigerated blood
• Specimen more than 72 hours old

Remarks

Lab Staff: Yellow Top (ACD Solution) is an acceptable, but not preferred, collection container for bone marrow and whole blood. Do not discard.

CPT Codes

88184 First marker
88185 Each additional marker
Professional fees will also apply

Effective/Revised

11/19/2019

Lymphoid neoplasms, which include the majority of non-Hodgkin’s lymphomas and both the acute and chronic leukemias, are derived from clonally expanded, developmentally arrested cells of B- or T-lymphocyte lineage. Studies have indicated that lymphoid neoplasms often exhibit the characteristics of normal cells at various stages of lymphoid development. An early and critical step in lymphoid cell development is the rearrangement of genes encoding antigen receptors—immunoglobulins or T-cell receptors—in B- and T-cells, respectively. Rearrangement of the antigen receptor genes is required for the production of immunoglobulin or T-cell receptor and is a mechanism that provides for a vast repertoire of diverse antigen receptor types within the immune system. As neoplastic counterparts of normal B and T lymphocytes, the lymphoid neoplasms also show evidence of rearrangement of their antigen receptor genes. Because the lymphoid neoplasms are derived from a single cell, the identical rearrangement pattern is faithfully reproduced throughout the clonal descendants of the original neoplastic cell. In B-cell neoplasms, this is usually detected using flow cytometry and analysis of Kappa and Lambda light chains expression. Normal B-lymphocytes will secrete immunoglobulin with either Kappa or Lambda light chains. In normal populations, this is seen as a standard 60% Kappa bearing B-cells to 40% Lambda bearing B-cells. When a neoplastic cell undergoes clonal expansion, this 60:40 ratio is upset. In many Chronic Lymphoid Leukemias, populations of almost 100% Kappa or Lambda cells can be seen. In other more discrete populations, Kolmogorov-Smirnov analysis of the data is necessary to determine if a clonal population exists. Leukocyte immunophenotyping by flow cytometry is the principle method by which the maturation and lineage of a cell can be determined. Leukemias represent abnormal proliferations of hematopoietic cells that are arrested at a discrete state of differentiation. Since leukemic cells do not show abnormal morphological changes in the same manner as other tumors, a definitive diagnosis of a leukemia or another hematopoietic neoplasm can be made only by the finding of a shift in the distribution or maturity of a cell population. Utilizing monoclonal antibodies to cellular antigens, an immunophenotype can be established for each population of cells present in the specimen, and the percentage of each population determined.