Definition of Erythroid Differentiation Subsets in Normal Human Bone Marrow Using FlowSOM Unsupervised Cluster Analysis of Flow Cytometry Data

摘要

Erythropoiesis is a complex process that ensures the production of about 200 billion erythrocytes every day, at a rate of almost 2 million per second in humans. Knowledge of the maturation process of red blood cells comes mostly from morphological analysis of bone marrow (BM) smears or biopsies, colony unit formation studies in cultures, and electron microscopy.1-3 Multiparameter flow cytometry (MFC) explorations added new information about the kinetics of expression and the role of various erythroid lineage-associated markers such as CD105 (endoglin), CD71 (transferrin receptor), and CD36 (thrombospondin receptor).4,5 A relatively limited number of MFC studies have been published concerning erythroid maturation,6,7 lately aiming at providing information about erythroid lineage alterations in early stages of unilineage myelodysplastic syndromes characterized by isolated anemia.8 The Red score, proposed in 2013, presented a bold approach using nonlysed BM samples in a panel where the addition of a DNA dye allowed to exclude from analysis mature red blood cells that have lost their nucleus.9 More recently, our group in Lund published a similar MFC approach, including multiparametric radar representation, to assess erythroid maturation with a single 7-color panel.10 This strategy allowed to delineate and confirm the differentiation pattern of erythropoiesis characterized by the following steps: (1) loss of CD117, (2) transient expression of CD105, and (3) appearance and decrease of CD36 and CD71. This highly reproducible representation, however, relied on traditional supervised sequential gating along the continuum of maturation.