Choice and assessment of clinical laboratory parameters in white blood cell line disorders. Cytochemical and immunophenotype characteristics of leukocytes in chronic leukemias (lymphocytic and granulocytic).
WBC – Lymphocytes, monocytes, granulocytes (eosinophils, neutrophil and basophil)
Blast cell (more than 20% in BM):
- changes in size
- changes in nucleus shape
- changes in nucleolus
- vacuolisation
- appearance of granules in cytoplasm
- appearance of auer roads
ACUTE: Run a complete blood count (Decreased; erythrocytes, Hb, thrombocytes. Leukocytes can be normal/high/low. Cytochemical tests (analysis of enzymes and cell content to classify which type of leukaemia) Flowcytometry (light passed through cells in a suspension to obtain cell size and structure). Bone marrow biopsy (either of the solid matter or CSF)
CHRONIC: Run a complete blood count (Decreased; erythrocytes and Hb. Thrombocytes slightly elevated at first, leukocytes greatly elevated) Blood smear (peripheral blood – all forms/maturation stages of neutrophils present)
- Chronic leukemia’s: Onset tends to be slow. Cells mature abnormally and accumulate in various organs. Impaired ability to fight infections and assist in repairing injured tissues. Unlike acute forms of leukemia, these disorders may persist for months or many years. A distinctive feature of the chronic myelocytic type is its invariable conversion, if untreated, to a more rapidly fulminating acute type, leading to rapid death.
- Chronic Myeloid Leukemia (CML): Common disorder affecting the middle aged. 90% of cases have a characteristic chromosomal abnormality - translocation between chromosomes 9 and 22 (Philadelphia chromosome). The Philadelphia chr. causes uncontrolled reproduction and proliferation of all types of WBC and platelets.
- CBC, DBC: Leukocytosis WBC: 50-400 G/l. Thrombocytopenia or thrombocytosis and a left shift in the granulocyte series (granulocytic precursors of all degrees of differentiation and maturation are present in the peripheral blood smear). Basophilia. Moderate normocytic and normochromic anemia. Reticulocytopenia
Clinical chemistry: LDH and uric acid concentrations are elevated. Serum B12 levels are increased due to the production of transcobalamine
Advanced diagnostics: Bone marrow: marked hypercellularity, with myeloid hyperplasia, which results in an increased M:E ratio. Basophils and eosinophils are usually increased. Megacaryocytes are numerous.
Differential diagnosis: The leukocyte alkaline phosphatase (LAP) score is of special diagnostic importance, because it permits the differentiation of CML from leukemoid reaction. The neutrophils in CML are deficient in LAP, while those in leukemoid reaction give rise to an increased score