Clinical Significance of Flow Cytometry Findings in Brazilian Patients with De Novo Acute Myeloid Leukemia

Abstract

Introduction: Immunophenotyping by flow cytometry (FC) is an essential method for diagnosis and classification of acute myeloid leukemias (AML), and its extensive use could identify blast cell subpopulations with phenotypes rarely seen in normal myelopoiesis, correlating with clinical, morphological and prognostic characteristics. Methods: In this study we analyzed 143 cases of AML, examining them for leukemia-associated immunophenotype (LAIP) by FC immunophenotyping in leukemic cells using a panel of monoclonal antibodies (MoAb) for diagnosis and classification of acute leukemia (AL). At the same time, clinical, demographic and hematological data of these patients were also investigated. Most patients were male adults and splenomegaly and hepatomegaly were present in most cases. Results: Immunophenotyping showed a characteristic profile of AML with expression of pan-myeloid antigens CD13, CD33 and myeloperoxidase (MPO), combined with CD34 and CD117 in most cases. Expression of CD14 and CD64 were observed in AML with monocytic component (AML-M4/M5), CD235a, CD36 and CD71 in cases of erythroleukemia (AML-M6) and platelet glycoproteins CD41, CD42b and CD61 in acute megakaryocytic leukemia (AML-M7). Regarding the aberrant phenotype, higher levels of expression of CD4, CD7 and CD56 were observed, corresponding to 24.5%, 22.4%, and 16.1% of the cases, respectively. Conclusion: We conclude that LAIP, as they are described here, were present in the vast majority of cases of investigated AML, with a relevant association with prognostic factors, clinical data and cytomorphological classification.