Relation between FMS-like tyrosine kinase 3 factor and hematological parameter in acute lymphoblastic leukemia patients by flow cytometry

BACKGROUND: Acute lymphoblastic leukemia (ALL) is a heterogeneous disorder that is caused by the clonal expansion of immature lymphoid cells with a high rate among children more than adults. FMS-like tyrosine kinase 3 (FLT3) is a cellular receptor belongs to the Class III receptor tyrosine kinase family. The main expression of FLT3 on bone marrow (BM) cells especially CD34+ hematopoietic stem cells, early progenitor cells, dendritic progenitor cells, and other cells of organs (brain, placenta, and testis). Activation of FLT3 results in increased cell proliferation, decreased cell apoptosis, and inhibition of differentiation of cells. This study aims to detect the expression of the FLT3 cluster of differentiation antigen 135 (CD135) in childhood B-ALL patients. Moreover, to correlate this expression with hematological parameters include a complete blood count and BM examination findings and clinical parameters. PATIENTS, MATERIALS AND METHODS: This study was conducted on 30 newly diagnosed pediatric ALL patients. Diagnosis of the disease was based on the blood film, BM examination findings, cytochemistry, and flowcytometry of peripheral blood (PB) and/or BM sample, 1 ml of PB and/or BM sample was collected in EDTA tubes for flowcytometry for detection of CD135. RESULTS: This study found that male patients were more than females with a male-to-female ratio (1.14:1) and a median age of 5 years. Most of the patients had a positive expression of the FLT3 receptor and according to NCI risk groups, 60% of patients fall in the standard risk and 40% in the high-risk group. There was a significant correlation between the level of FLT3 (CD135) and age but no significant correlation with hemoglobin, white blood count, platelets, and peripheral or BM blast percentage. CONCLUSION: In this study, the patients with positive FLT3 blast cells (which is a bad prognostic factor) were associated with good prognostic factors. This proves that FLT3 is an independent prognostic factor.