Diagnostic application of flow cytometric characteristics of CD34+ cells in low-grade myelodysplastic syndromes

Abstract

were analyzed using 4-color flow cytometry (FCM). We objectively determined reference ranges of 13 parameters related to CD34 ؉ cells with data from controls. InLGw/oRS patients, various abnormalities of CD34 ؉ cells-eg, decrease in CD34 ؉ B-cell precursors, aberrant expression or overexpression of various antigens on CD34 ؉ myeloblasts-were observed. We constructed a reproducible, flow cytometric scoring system for LGw/oRS diagnosis. High scores were observed in 16 of 27LGw/oRS patients, regardless of the presence or absence of chromosomal aberrations, but not in any of the 90 controls. Among LGw/oRS patients with chromosomal aberrations, patients with trisomy 8 or del20(q) had low FCM scores (P ‫؍‬ .002). As a result, most LGw/oRS patients were identified based on high FCM score, chromosomal aberration, or both.

Multicenter validation of a reproducible flow cytometric score for the diagnosis of low-grade myelodysplastic syndromes: results of a European LeukemiaNET study

“…The reliability of the adopted gating strategy was previously reported, 15,19,20 and was verified in addition in 30 patients enrolled in this study (Online Supplementary File S1).…”

“…[14][15][16] Consistent immunophenotypic aberrations reported in the CD34 + cell compartment in MDS are: an increase of the myeloid-committed CD34 + population, 10,15,17 a decrease of B-cell progenitors, 15,18 co-expression of stem cell-and late stage-myeloid antigens, expression of lymphoid antigens 7,8,11 and abnormal CD45 expression. 15 We previously reported that data for three of these parameters (percentage of myeloblasts, percentage of Bcell progenitors, and myeloblast CD45 expression) together with the evaluation of side scatter (SSC) on granulocytes are reproducible in many laboratories when measured by methods ensuring little inter-operator variability, 19,20 and when combined are able to differentiate correctly patients with MDS from patients with non-clonal cytopenia. 20 To be implementable in clinical practice, an extensive validation of this approach is required.…”

“…In the CD45/SSC dot plot, we identified the cell population consisting predominantly of B-progenitor cells which formed an easily recognizable cluster that had the lowest SSC and relatively low CD45 expression (P5, called "B-progenitor-related cluster" in this paper). 15,17,19 Other CD34 + cells (P4) showing more SSC and a wider distribution of CD45 expression consisted predominantly of myeloblasts (called "myeloblast-related cluster" in this paper). 15,17,19 The phenotypes of CD34 + cells in both myeloblastrelated and B-progenitor-related clusters ( Figure 1C1) was determined: in all 30 cases analyzed, CD34…”

“…15,19,20 Briefly, on the forward scatter (FSC)-versus-side scatter (SSC) display, we defined "all nucleated cells" (P1, Figure 1A), and cells with relatively low SSC were gated (P2) and then plotted on a CD45 versus CD34 display ( Figure 1B). Next, CD34…”

Unravelling the relevance of CLEC12A as a cancer stem cell marker in myelodysplastic syndrome

“…When the morphological dysplastic features are mild or even absent and PB cytopenias are persistent the diagnosis is termed idiopathic cytopenias of undetermined significance (ICUS) (Valent et al , 2012; Bejar & Steensma, 2014). Evaluating myelodysplastic features using flow cytometry is a growing field of interest and highly sensitive multicolour immunophenotypic profiling and accompanying scoring systems have proven useful in MDS, both in diagnostic and prognostic terms (Ogata et al , 2006; van de Loosdrecht et al , 2008). …”