PB1991: NEW MONOCYTE HEMATOLOGICAL PARAMETERS AS AN IMPORTANT INDICATOR OF MDS PATIENTS WITH POSITIVE OGATA SCORE - A PRELIMINARY STUDY

Topic: 9. Myelodysplastic syndromes - Biology & Translational Research Background: Myelodysplastic syndrome (MDS) is a type of heterogeneous myeloid clonal disease that is usually diagnosed by a combination of multiple laboratory tests, including analysis of peripheral blood cells, bone marrow cell morphology, and cytogenetics. The morphological assessment of monocytes with a hematological analyzer could be useful in the evaluation and monitoring of MDS patients. The monocytes importance in MDS patients remains unclear, although other studies have suggested that these immune cells may retain a significant function, contribute to the development or progression of the disease and provide important information about the status and prognosis of MDS. Over the last few years, flow cytometry (FCM) has shown its importance in the diagnosis and prognosis of MDS. The Ogata score algorithm analyzes the expression of various cell surface markers on different cell populations, such as myeloblasts and erythroid cells, and assigns a score based on the degree of abnormality. In addition, the Ogata score can also help monitor disease progression and treatment response in MDS patients. However, the immunophenotype of bone marrow monocytes has rarely been studied in MDS disorders. New easily accessible parameters evaluating the status of monocytes together with the Ogata score can provides important insights to the role of monocyte in the diagnosis, differentiation and prognosis of MDS. Aims: The aim of the study was to assess the new monocytes scattering parameters in MDS patient with and without positive Ogata score. Methods: Bone marrow from 51 patients with MDS, including 30 patients with positive Ogata score were examinated. The Ogata score were analyzed using flow cytometry method and referred to a specific cytometric algorithm. The new monocytes parameters such as: width of dispersion of monocytes complexity (NE-WX), width of dispersion of monocyte fluorescence (MO-WY), width of dispersion of monocyte size (MO-WZ), monocyte complexity (MO-X), monocyte fluorescence (MO-Y), monocyte size (MO-Z) were measured. The study was conducted using the Sysmex XN-Series hematological analyzer. Results: MO-Y had statistically higher values in the group of MDS patients with positive Ogata score (Ogata score≥ 2) when compared with that of patients with negative Ogata score (respectively, 114 vs. 111, p< 0.05). We observed higher median proportion of MO-WX, MO-WY and MO-WZ in MDS patients with positive Ogata score when compared with that of patients with negative Ogata score (respectively, 375 vs. 282, 1080 vs. 785, 688 vs. 575, p> 0.05). Interestingly, no differences were observed for MO-X and MO-Z parameters. Summary/Conclusion: This study showed that combining of the simple cytometric test Ogata score with new hematological monocyte parameters analysis can provide valuable information for the diagnosis and monitoring of patients at different risk of MDS severity. The evaluation of the Ogata score with monocyte status analysis can provide a more comprehensive estimation of the patient’s bone marrow function and disease condition. Keywords: Myelodysplastic syndrome, Monocyte, Immunophenotype