Leukemia Stem cell Markers: CD 123 and CD25 are poor prognostic markers in adult Acute Myeloid Leukemia Patients

Background: Acute myeloid leukemias (AML) still remain a challenge for hematologists. Though an impressive number of prognostic factors have been identified in AML, it still ranks one of the highest cancer related deaths. Several studies have indicated their origin from a rare population of leukemic cells, known as leukemic stem cells, which initiate the disease and contribute to frequent relapses. Leucocyte interleukin-3 receptor ? (CD123) and leucocyte interleukin-2 receptor ? (CD25) are regarded as markers of leukemia stem cells. Aim: The aim of this study was to investigate CD123 and CD25 expression in newly diagnosed patients with AML by flow cytometry and correlate their expression with disease prognostic parameters and patients’ outcome at day 28 of therapy. Patients and Methods: This study was conducted on 30 newly diagnosed patients with AML admitted to Ain Shams University Hospitals; Egypt. They were subjected to full medical history and clinical examination, complete blood count with examination of peripheral blood and bone marrow (BM) smears, routine immunophenotyping of BM or whole peripheral blood and cytogenetic studies. The expression of CD123 and CD25 was performed using the following panel where gated blast cells were stained for CD45, CD38, CD34, CD123 and CD25. Results: In the current study, CD123 was expressed in 13/30(43.3%) and CD25 was expressed in 4/30(13.3%). CD123 expression positively correlated with higher total leucocytic count and BM blast percentage and CD25 expression. Both CD123 and CD25 expression had a significantly poor effect on outcome even in the good prognostic cytogenetic subgroups. Conclusion: Results of our study clearly demonstrate the poor prognostic significance of CD123 and CD25 expression in AML patients. This may represent additional prognostic tool in risk stratified management of AML patients.