Flow cytometry evaluation of erythroid and myeloid dysplasia in patients with myelodysplastic syndrome

Abstract

The purpose of this study was to develop a flow cytometric approach to the evaluation of marrow dysplasia in myelodysplastic syndromes (MDS). We first studied a cohort of 103 MDS patients as well as 46 pathological and healthy controls. Flow cytometry data were expressed as percentage of positive cells. Analysis of erythroid cells showed higher proportions of immature cells (Po0.001) and decreased levels of CD71 expression on nucleated red cells (P ¼ 0.02) in MDS. Analysis of myeloid cells showed lower proportions of CD10 þ and higher proportions of CD56 þ granulocytes (Po0.001), and increased ratios of immature to mature cells (P ¼ 0.007). Since no single immunophenotype could accurately differentiate MDS from other conditions, we used discriminant analysis for generating erythroid and myeloid classification functions using combinations of immunophenotypic parameters. These functions were prospectively validated in a testing cohort of 69 MDS patients and 46 pathological controls. A diagnosis of MDS was obtained in 60/69 cases (87%). No false-positive results were noticed among controls. Significant correlations between values of these functions and both degree of morphological dysplasia and the International Prognostic Scoring System were found. These findings indicate that flow cytometry evaluation of marrow dysplasia is feasible and may be useful in the work-up of individual MDS patients.

Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group

“…The endoglin marker CD105 is also used, but data on this particular marker are scarce. 9,22,28,36,56 Some of the aberrancies that are currently considered relevant (Table 1), and their accompanying pitfalls, are discussed here.…”

“…By contrast, a decrease in erythroid progenitors, due to apoptosis or erythropoietin deficiency, can also be observed. 9,22,28,36,56 Moreover, quantification of the amount of erythroid progenitors may be affected by red-cell lysing procedures, which may potentially lyse some of the nucleated red blood cells. It might therefore be worthwhile to analyze the erythroid/myeloid ratio before and after lysis.…”

“…9,22,28,36,56 An example is displayed in Figure 4. It should be kept in mind that the transferrin receptor (CD71) has a role in iron uptake and can also be present on non-erythroid immature cells, as it is required for their metabolism.…”

Flow cytometry evaluation of erythroid dysplasia in patients with myelodysplastic syndrome

“…The degree of erythroid dysplasia was defined according to the following morphological scoring system: 0 (absence of dysplasia, 0-2% of abnormal cells), 1 (mild dysplasia, 3-9% of abnormal cells), 2 (moderate dysplasia, 10-29% of abnormal cells) and 3 (severe dysplasia, 30% or more abnormal cells). 11 Cytogenetic analysis was performed at diagnosis, using standard G-banding with trypsin-Giemsa staining as recently described. 16 The International Prognostic Scoring System (IPSS) was employed to define prognosis according to Greenberg et …”

“…6 Several studies have later evaluated the clinical utility of this approach in MDS patients [7][8][9][10] and we have recently developed a flow-cytometry approach for the evaluation of marrow dysplasia using discriminant analysis to generate erythroid and myeloid classification functions that was proven to be sensitive in a high proportion of cases with indeterminate morphology, as well as repeatable and reproducible in a intra-laboratory setting. 11 Evaluation of erythroid dysplasia represents a challenge in the immunophenotypic analysis of myelodysplastic marrows, mainly because of the limited availability of specific antibodies. To overcome this limitation, we developed a flow-cytometric approach largely based on the evaluation of proteins of erythroid iron metabolism.…”