Immunophenotypic analysis of erythroid dysplasia and its diagnostic application in myelodysplastic syndromes

Background/Aim: Abnormal immunophenotypes of haematopoietic cells in myelodysplastic syndromes (MDS) have been identified by flow cytometry (FCM) as a typical characteristic of myeloid dysplasia. Considering that most MDS patients show varying degrees of erythroid dysplasia, we analysed the immunophenotypic feature of erythroblasts to evaluate its diagnostic application in MDS. Methods: Erythroid antigens CD71 and CD105 expression were analysed using FCM. The development index (DI) acquired by log transformation of the CD71/CD105 expression ratio was used to denote the erythroid maturation and distinguish patients with non-clonal cytopenias from low-risk MDS. The diagnostic quality of DI in distinguishing MDS from non-clonal cytopenia patients was evaluated using the receiver-operator characteristic (ROC) curve. Results: Under-expression of CD71 and over-expression of CD105 were detected in erythroblasts of MDS patients compared with non-clonal cytopenias. The diagnostic test showed good diagnostic power that the area under the ROC curve was greater than 0.9. The diagnostic sensitivity and specificity were 75.6% and 92.3%, respectively, according to the DI threshold defined by the ROC curve in low-risk MDS patients with normal karyotypes. Moreover, the DI showed a positive correlation with the haemoglobin level, and the MDS patients with lower DI usually showed frequent red cell transfusion. The patients with a lower DI generally had the HLA-DR15 allele or marrow hypocellularity. Conclusion: Developmental defects and immune-associated factors may contribute to the erythroid dysplasia. The DI derived from ratios of CD71 and CD105 expression is a useful marker to characterise dyserythropioiesis associated with MDS and can be helpful in distinguishing it from dyerythropoiesis associated with non-clonal disorders.