Immunophenotypic analysis of erythroid dysplasia in myelodysplastic syndromes. A report from the IMDSFlow working group

Abstract

C urrent recommendations for diagnosing myelodysplastic syndromes endorse flow cytometry as an informative tool. Most flow cytometry protocols focus on the analysis of progenitor cells and the evaluation of the maturing myelomonocytic lineage. However, one of the most frequently observed features of myelodysplastic syndromes is anemia, which may be associated with dyserythropoiesis. Therefore, analysis of changes in flow cytometry features of nucleated erythroid cells may complement current flow cytometry tools. The multicenter study within the IMDSFlow Working Group, reported herein, focused on defining flow cytometry parameters that enable discrimination of dyserythropoiesis associated with myelodysplastic syndromes from non-clonal cytopenias. Data from a learning cohort were compared between myelodysplasia and controls, and results were validated in a separate cohort. The learning cohort comprised 245 myelodysplasia cases, 290 pathological, and 142 normal controls; the validation cohort comprised 129 myelodysplasia cases, 153 pathological, and 49 normal controls. Multivariate logistic regression analysis performed in the learning cohort revealed that analysis of expression of CD36 and CD71 (expressed as coefficient of variation), in combination with CD71 fluorescence intensity and the percentage of CD117 + erythroid progenitors provided the best discrimination between myelodysplastic syndromes and non-clonal cytopenias (specificity 90%; 95% confidence interval: 84-94%). The high specificity of this marker set was confirmed in the validation cohort (92%; 95% confidence interval: 86-97%). This erythroid flow cytometry marker combination may improve the evaluation of cytopenic cases with suspected myelodysplasia, particularly when combined with flow cytometry assessment of the myelomonocytic lineage.

Flow cytometry “Ogata score” for the diagnosis of myelodysplastic syndromes in a real‐life setting. A Latin American experience

“…Another strategy in order to increase the MDS diagnosis sensitivity is to combine two FC scores (eg, Ogata and Red Score improve the sensitivity to 88%) . Another study evaluating the combination of the “Ogata score” with the erythroid parameters recommended by IMDSFlow working group (CD36 and CD71 distribution, CD36 expression on erythroid lineage and CD117+ erythroid precursors) showed an improved diagnostic power (sensitivity of 86% and specificity of 95%) . Furthermore, integrating the “Ogata score,” “Wells FCSS,” and the erythroid parameters recommended by IMDSFlow working group, into the so‐called Integrated Flow Cytometry score (iFCs), showed 80% sensitivity and 95% specificity .…”

“…9,23,30,31 One important drawback of the "Ogata score" is that the sen- 23 Another study evaluating the combination of the "Ogata score" with the erythroid parameters recommended by IMDSFlow working group (CD36 and CD71 distribution, CD36 expression on erythroid lineage and CD117+ erythroid precursors) showed an improved diagnostic power (sensitivity of 86% and specificity of 95%). 33 Furthermore, integrating the "Ogata score," "Wells FCSS," and the erythroid parameters recommended by IMDSFlow working group, into the so-called Integrated Flow Cytometry score (iFCs), showed 80% sensitivity and 95% specificity. 34 We are now planning to incorporate the Red Score 23 in order to improve the sensitivity of the "Ogata score" among LA laboratories.…”

Determination of the proliferative fractions in differentiating hematopoietic cell lineages of normal bone marrow

“…In the last few years, increasing knowledge is gathered about specific cell surface protein expression patterns during maturation of different hematopoietic cell types, in particular for the process of erythropoiesis (9,10,13,15,16,18,19). During normal hematopoiesis, different blood cell types are produced in the BM depending on physiological requirements.…”

“…This resulted in a multiparametric differentiation pathway consisting of an arbitrary number of 20 immunophenotypic stages of maturation. The monocytic maturation pathway was drawn using the CD14 versus CD64 plot ( Figure S1B) (15), while for the erythropoiesis the CD71 versus CD235a plot was used ( Figure S1C) (13,14,17,18). For the Ki-67 positive cells, the same maturation pathway was drawn in a CD13 versus CD11b dot plot ( Figure S1A; lower row).…”

Usability of femoral head bone marrow to verify reference ranges for the assessment of myelodysplasia by flow cytometry

“…. Although it has been recognized that flow cytometry might be a supporting technique in diagnosing MDS the revised WHO 2016 does not require or recommend explicitly its use in the integrated work‐up or evaluation of dysplasia. The WHO states that if flow cytometry is performed for diagnosing MDS, it should always be embedded in an integrated report that includes morphology and cytogenetics …”