Clinical Impact of Percentage of Natural Killer Cells and Natural Killer-Like T Cell Population in Acute Myeloid Leukemia

BACKGROUND: Natural killer (NK) function defects have been seen in many hematological malignancies, including acute myeloid leukemia (AML). AML is associated with deficient human leukocyte antigen (HLA) expression on leukemia blasts which become targets for killing by NK and natural killer-like T (NKT) cells. However, NK and NKT cells are not effective in killing autologous leukemia blasts, maybe due to number or functional abnormalities. The aim of the work was to detect the number and percentage of NK and NKT cells in patients with AML and the impact of their percentage on the prognosis, response to treatment and survival. METHODS: Bone marrow and peripheral blood samples were collected from 50 adult patients diagnosed as de novo AML who presented to the Hematology Unit in the Oncology Center Mansoura University (OCMU) at time of diagnosis. NK and NKT cells were detected by using immunophenotyping by expression of cell surface and cytoplasmic markers (anti-CD3 fluorescein isothiocyanate (FITC), anti-CD16/56 phycoerythrin (PE)). RESULTS: We observed significant reduction in the median values of NK and NKT cells in AML patients in comparison to normal values. There was an insignificant correlation to response to induction treatment. While a significant correlation to overall survival (OS) (P = 0.03) was observed. The correlation to risk stratification was significant with NK cells (P < 0.001), but not with NKT cells (P = 0.23). CONCLUSION: We concluded that the number and percentage of NK and NKT cells decreased significantly in AML patients and the frequency of NK and NKT cells is inversely proportionate with prognosis and OS in studied AML patients. We recommend correlating both number and function of NK and NKT cells in future studies to help provide a wide field of interest for possibility of demonstrating novel therapies using NK cells for curing AML.