Combined flow cytometric assessment of CD45, HLA-DR, CD34, and CD117 expression is a useful approach for reliable quantification of blast cells in myelodysplastic syndromes

Background. Quantification of bone marrow (BM) blasts by cytomorphology is essential for the diagnosis of myelodysplastic syndromes (MDS). Owing to its subjectivity and the potential impact of dysplastic features on accurate identification of blast cells, more objective approaches are required, mult...

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Bibliographic Details
Authors: Sandes, Alex Freire [UNIFESP]; Kerbauy, Daniela Márcia Bahia [UNIFESP]; Matarraz, Sergio; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Lopez, Antonio; Orfao, Alberto; Yamamoto, Mihoko [UNIFESP]
Format: Article
Status:Published version
Publication date:2013
Country:Brasil
Institution:UNIFESP
Repository:Repositório Institucional da UNIFESP
Language:English
OAI Identifier:oai:repositorio.unifesp.br:11600/36222
Online Access:http://dx.doi.org/10.1002/cyto.b.21087
http://repositorio.unifesp.br/handle/11600/36222
Access Level:Open access
Keyword:myelodysplastic syndromes
blast cell count
flow cytometry
morphology
Description
Summary:Background. Quantification of bone marrow (BM) blasts by cytomorphology is essential for the diagnosis of myelodysplastic syndromes (MDS). Owing to its subjectivity and the potential impact of dysplastic features on accurate identification of blast cells, more objective approaches are required, multiparameter flow cytometry (MFC) being a particularly promising approach in this regard. However, no consensus exists about the optimal combination of markers and strategy to be used. Methods. BM blast counts from 74 MDS patients were evaluated by morphology versus four different MFC phenotypic criteria: CD34+, CD34+ and/or CD117+, CD34+, and/or CD117+HLA-DR+, and CD34+ and CD117+HLA-DR+ plus CD64+CD14/lo cells. for each criterium, the percentage of blasts was calculated using either all BM nucleated cells or non-erythroid CD45+ cells as denominator. Results. the number of CD34+ and/or CD117+HLA-DR+cells showed the highest correlation and agreement with morphological counts, only a minor proportion of cases being misclassified by MFC vs. morphology for the >5% and >10% classification thresholds. in turn, a CD34+ phenotype was insufficient to correctly identify and quantify blasts. Conversely, usage of non-erythroid BM cells as denominator, or inclusion of CD34+ and/or CD117+HLA-DR+ plus CD64+CD14lo cells were both associated with overestimated blast counts. Conclusions. Quantification of CD34+ and/or CD117+HLA-DR+ cells (from all nucleated BM cells) by MFC is an efficient method for the enumeration of blasts in MDS. However, caution should be taken with replacing morphology by MFC blast counts; its combined use may rather provide complementary information increasing the accuracy and reproducibility of BM blast cell counts in these patients. (c) 2013 International Clinical Cytometry Society