Malignant Leukocyte Immunophenotyping covers testing for the identification and characterization of leukemias or lymphomas in blood, bone marrow, and tissue specimens based on cell phenotype (including cell surface and cytoplasmic antigens) with or without ploidy analysis.
Malignant Leukocyte immunophenotyping Quality Control
- A normal blood or validated commercial control must be run monthly
- Cellular Immunology Standard CIML-S9
- Maximum acceptable specimen age is 48 h
- Cellular Immunology Standard CIML-S2
- Specimens must have a viability of 50% or greater
- Cellular Immunology Standard CIML-S3
- If the specimen exceeds the 48h maximum age and/or the minimum 50% viability, but is irreplaceable, then the results can only be reported if an abnormal population is definitively determined by the combination of the flow cytometric results with other clinical and technical features of the case taken into consideration.
- Cellular Immunology Standard CIML-S3c
- Values for the same marker(s) (clone, manufacturer, fluorochrome) used in multiple panel assay tubes must produce similar results for the same gated cell population.
- Cellular Immunology Standard CIML-S13a
- Specimen analysis should include examination of a normal cell population (e.g., lymphocytes) if the specimen composition permits such analysis. Marker presence or absence with qualitative intensity descriptions on both populations supports the aberrant results when the results for the normal cells are as expected.
- Cellular Immunology Standard CIML S12b and S13b
- Surface immunoglobulin analysis must include a pan B cell marker (e.g., CD19 or CD20) to assist in accurate assessment by eliminating non-specific staining of other cell types.
- Positive staining reactivity for surface immunoglobulin heavy chains (e.g., IgM and IgD) support the presence of immunoglobulin light chains. Light chain determination is important in establishing clonality, however, their analysis can be problematic. Blood cells must be washed free of plasma immunoglobulins before performing B cell analysis. Inconsistencies between surface immunoglobulin light chain and heavy chain assays is indicative of analytical difficulties and should be reported as such.