Flow cytometric Immunophenotyping and Hematological Findings at Diagnosis and Relapse of Pediatric Acute Lymphoblastic Leukemia Patients

Background: Acute lymphoblastic leukemia (ALL) is a common pediatric leukemia caused by lymphoid precursor proliferation. We analyzed immunophenotyping and hematological findings, as the risk of relapse, of pediatric ALL patients at diagnosis and relapse. Methods: Peripheral blood and bone marrow samples of 30 pediatric ALL patients were collected at diagnosis and at relapse. The latter was evaluated for immunophenotyping and cytochemical staining (Periodic Acid Schiff stain (PAS)), while hematological findings were assessed in the former one. Results: The percentage of PAS-positive patients, TdT, and CD4 expression were significantly higher at diagnosis than relapse (p = 0.027, 0.004, and 0.043, respectively), whereas the platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio were significantly lower at diagnosis (p = 0.004 and 0.032, respectively). There were correlations between immunophenotyping and hematology data, including: a) a negative correlation between CD4 expression with blast percentage (r = -0.927, p = 0.003) and hemoglobin level (r = -0.991, p < 0.001) at diagnosis and TdT expression with platelet count (r = -0.441, p = 0.017) at relapse, and b) a positive correlation between CD3 expression with PLR (r = 0.367, p = 0.046) at relapse. Conclusions: Results suggest that changes in immunophenotyping and hematology findings could be applied as relapse prognostic factors in ALL.