Flow Cytometry Immunophemotyping Evaluation in the Diagnosis of Acute Lymphoblastic Leukemia in Patients from Rio Grande Do Norte State, Brazil

The authors conducted a flow cytometry immunophenotyping study in patients with acute lymphoblastic leukemia (ALL) from Natal, Rio Grande do Norte state, Brazil. The patients (n=126) were newly diagnosed using a panel of monoclonal antibodies: CD1a, CD2, CD3, CD4, CD7, CD8, CD10, CD13, CD33, CD14, CD19, CD22, CD79a, CD117, CD34, anti-IgM, anti-TdT, anti-HLA-Dr, anti-human kappa and lambda light chains. Additional data, such as patient age and gender, clinical and laboratory findings such as the presence of tumor masses, lymphadenopathy, hepatomegaly, splenomegaly, leukemic infiltration into the central nervous system (CNS) were also investigated. Results showed that 56.7% of the cases were B-lineage ALL and 55% T-cell ALL. Moreover, we found that males were more affected by the disease, regardless of immunological classification. The correlation between age and immunological subtypes showed that the B-lineage ALL occurred more frequently in patients younger than 15 years of age, while the T-cell ALL subtype was more frequent in adults. Immunophenotypic profiles and morphological subtypes demonstrated a direct correlation between L3 subtype and B-lineage ALL, while L1 and L2 subtypes correlated more often with B-cell lineage and T-cell ALL, respectively. Correlation analysis between immunophenotypic and clinical profiles revealed that T-cell ALL was more associated with a higher incidence of lymphadenopathy, hepatomegaly, splenomegaly and CNS leukemic infiltration, in addition to showing a greater blast cell count in peripheral blood than the other subgroups. The data suggest that immunophenotyping is an important method in diagnosis, monitoring and prognosis when determining the pathological mechanisms of evolution in acute lymphoblastic leukemia.