Expression of G Protein–Coupled Receptor 56 (GPR56) in Acute Myeloid Leukemia

Abstract

Abstract Background Acute myeloid leukemia (AML) is a heterogeneous marrow-based clonal group of neoplasms that affects hematopoietic cells responsible for the production of myeloid lineages. Prognosis of AML is multifactorial and has been extensively studied, yet it’s highly dependent on the presence of leukemic stem cells (LSCs). G protein–coupled receptor 56 (GPR56) was introduced as a novel human LSC marker in AML patients as acknowledged by the engraftment potential of GPR56+ cells sorted from selected AML specimens, which contributed to leukemia propagation in mice. Aim of the work The aim of this study is to analyze GPR56 expression in de novo AML patients using flow cytometry. The results of GPR56 expression will be correlated with the clinical outcome of the patients as well as other laboratory parameters. Subjects and Methods The study was carried out at Ain Shams University hospitals on a total number of 40 AML patients attending hematology-oncology unit during the period from November 2016 to July 2017, in addition to 20 healthy control subjects. Patients were assessed at day 28 after induction of treatment by bone marrow examination and minimal residual disease analysis, and follow up of the disease course was done. Results GPR56 was highly expressed above mean in 62.5% of AML patients. High values were significantly related to failure to attain complete remission, whereas it lacked prognostic significance to patient outcome and cytogenetic subgroups. Conclusion The poor prognostic impact of GPR56 was partially validated in our study. Recommendations Flow cytometric evaluation of GPR56 should be incorporated into the initial laboratory work-up for all newly diagnosed AML patients.