Study of myelodysplastic features in patients with myelodysplastic syndromes by multicolor flow cytometry

Background . Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal diseases of the hematopoiesis system characterized by dismyelopoiesis and cytopenia, the presence of cytogenetic aberrations and a high risk of transformation into acute myeloid leukemias. Diagnosis of MDS requires a comprehensive approach and mandatory performance of cytological, cytochemical and cytogenetic studies of bone marrow aspirate, as well as histological examination of trephine biopsy. However, in some cases it is necessary to undergo a diagnostic test that would allow verification of the MDS. The study of bone marrow aspirate by multicolor flow cytometry (MFC) can be considered as an additional diagnostic criterion in the diagnosis of MDS. The objective of the study was to estimate the incidence of myelodysplastic features in patients with various forms of MDS by the MFC method. Materials and methods . The study included 79 patients with MDS: 8 with MDS with 5q deletion, 33 with MDS without excess blast cells and 38 with excess of blasts. A bone marrow aspirate test was performed by 6-color flow cytometry. The control group included 35 donors of allogeneic bone marrow. The analysis resulted in a conclusion on the Ogata score scale, the Wells prognostic scale and the combined Ogata–Wells scale. When using the screening method, the presence of two or more cytometric signs of MDS was detected in 60 (75.9 %) of 79 MDS patients. Wells score was higher in MDS group with an excess of blast than in others. Using the combined Ogata–Wells scale, cytometric aberrations were found in 70 (88.6 %) of 79 MDS patients. In patients with MDS with an excess of blasts, the incidence of increased CD34+ and/or CD117+ myeloid cells was higher than in MDS patients without an excess of blasts and an MDS with a 5q deletion. The frequency of abnormal cytometric parameters (anomalous expression of CD34, CD117, CD56+ myeloblasts) in these groups did not differ. In patients with isolated 5q deletion and MDS without excess of blasts, an increased proportion of CD7+CD34+ cells was more often detected than in MDS with an excess of blasts. Conclusion . Thus, cytometric abnormalities in MDS are common, even in patients without excess of blasts. The MFC method can be used as an additional diagnostic method in the initial diagnosis of MDS.