Diagnostic Utility of Immunophenotyping by Flow Cytometry for Diagnosis and Classification of Acute Leukemias in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia
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Date
2016-11
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Addis Ababa University
Abstract
Background: Immunophenotypic characterization of acute leukemia is an important clinical
application of flow cytometery and has become a powerful tool contributing to proper diagnosis
and classification.
Objective: To phenotype and classify acute leukemias by flow cytometry using commonly used
markers for leukemia diagnosis.
Method: A total of 40 pediatric and adult patients diagnosed with acute leukemia were evaluated
by flow cytometry with 17 surface and cytoplasmic markers known to be useful in discriminating
different types of acute leukemia.
Results: 21 of 40 patients (52.5%) were classified as Acute Myeloblastic leukemia (AML) while
19 (47.5%) were identified as Acute lymphoblastic leukemia (ALL). Of all the ALL cases, 10 of
the 19 (52.6%) were B-ALL and 47.4% (9/19) were T-ALL. Markers of immaturity HLA-DR
and CD34 antigens were co expressed in 61% of AML cases, and 33% of T-ALL cases, whereas
CD34 was expressed in 50% of the B-ALL cases. MPO and CD13 were the most commonly
expressed markers of AML, whereas CD19 and cCD79a were present in all cases of B-ALL.
Cytoplasmic CD3 and CD7 were the most sensitive markers for T-ALL. Discrimination of AML
from ALL patients by flow cytometry was 80% concordant with traditional morphology. Notable
discrepancies occurred in cases where leukemia cells expressed markers for more than one
lineage.
Conclusion: Immunophenotyping by flow cytometry provides useful information to confirm
diagnoses of standard morphology methodology, to provide classifications where morphology is
indeterminate, and to provide further lineage and maturation information for ALL not obtainable
by morphology is needed for ALL cases. It thus represents an important tool among many in
leukemia classification and is realistic in the resource limited settings.
Key words: Leukemia, ALL, AML, Flow cytometry, Immunophenotyping
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Keywords
Leukemia, ALL, AML, Flow cytometry