Translation of the Morphological Hallmarks of Dyserythropoiesis to Objective Morphometric Parameters by Imaging Flow Cytometry.

Abstract

Introduction: Imaging flow cytometry (IFC) is a unique method combining multiparameter flow cytometry (MFC) with morphological evaluation of single cells. Since both analyses are integrated in the diagnostic work-up of myelodysplastic neoplasms (MDS), we wanted to explore the possibilities of IFC as a diagnostic tool for MDS, with focus on dyserythropoiesis.

Methods: We analysed fresh bone marrow (BM) aspirates from 26 patients with untreated MDS and MDS/MPN and compared them with 12 normal BM specimens (NBM) exploring the cytoplasmic compartment, nuclear abnormalities, and megaloblastoid changes.

Results: The cytoplasmic compartment in MDS showed higher contrast and variance values compared to NBM (p < 0.001). Cells with abnormal nuclei and binucleated forms were significantly increased in MDS compared to NBM (p < 0.05 for both features). Most binucleated forms were found in the mature compartment, and many of them were G1 phase arrested. All maturation stages showed a significant increase in cell size in MDS compared to NBM (p < 0.001). In addition, we found decreased nuclear condensation combined with increased cell size for all erythropoietic maturation stages in MDS compared to NBM (p < 0.001). Finally, our previously described MDS-specific aberrant population of mature erythroblasts with decreased expression of CD36 and/or CD71 showed denser chromatin than both the mature erythropoietic MDS cells without immunophenotypic aberrancies (p < 0.001) and NBM (p = 0.024).

Conclusion: IFC can detect the major morphological changes associated with dyserythropoiesis in MDS, including the novel findings of increased cytoplasmic texture and bilobated non-proliferating erythroblasts, allowing for objectivity and standardization.