Altered immunophenotypic features of peripheral blood platelets in myelodysplastic syndromes

Abstract

BackgroundMultiparameter flow cytometric analysis of bone marrow and peripheral blood cells has proven to be of help in the diagnostic workup of myelodysplastic syndromes. However, the usefulness of flow cytometry for the detection of megakaryocytic and platelet dysplasia has not yet been investigated. The aim of this pilot study was to evaluate by flow cytometry the diagnostic and prognostic value of platelet dysplasia in myelodysplastic syndromes. Design and MethodsWe investigated the pattern of expression of distinct surface glycoproteins on peripheral blood platelets from a series of 44 myelodysplastic syndrome patients, 20 healthy subjects and 19 patients with platelet alterations associated to disease conditions other than myelodysplastic syndromes. Quantitative expression of CD31, CD34, CD36, CD41a, CD41b, CD42a, CD42b and CD61 glycoproteins together with the PAC-1, CD62-P, fibrinogen and CD63 platelet activation-associated markers and platelet light scatter properties were systematically evaluated. ResultsOverall, flow cytometry identified multiple immunophenotypic abnormalities on platelets of myelodysplastic syndrome patients, including altered light scatter characteristics, over-and under expression of specific platelet glycoproteins and asynchronous expression of CD34; decreased expression of CD36 (n=5), CD42a (n=1) and CD61 (n=2), together with reactivity for CD34 (n=1) were only observed among myelodysplastic syndrome cases, while other alterations were also found in other platelet disorders. Based on the overall platelet alterations detected for each patient, an immunophenotypic score was built which identified a subgroup of myelodysplastic syndrome patients with a high rate of moderate to severe alterations (score>1.5; n=16) who more frequently showed thrombocytopenia, megakaryocytic dysplasia and high-risk disease, together with a shorter overall survival. ConclusionsOur results show the presence of altered phenotypes by flow cytometry on platelets from around half of the myelodysplastic syndrome patients studied. If confirmed in larger series of patients, these findings may help refine the diagnostic and prognostic assessment of this group of disorders.

Bone marrow immunophenotyping by flow cytometry in refractory cytopenia of childhood

“…8,10,11,[38][39][40] Flow cytometric evaluation of megakaryopoieis still has its limitations, but it was recently shown that abnormalities detected in peripheral blood platelets by flow cytometry are of diagnostic significance in adult MDS. 41 Future studies will be needed to reveal whether immunophenotyping of platelets and/or megakaryocytes can be of additional value in distinguishing RCC from (v)SAA as well. Apart from flow cytometric immunophenotyping, deep-sequencing approaches, which have now become readily available, but have not yet been systematically applied in RCC and (v)SAA, might be of value in identifying differences between the two groups.…”

Clinical Implication of Multi-Parameter Flow Cytometry in Myelodysplastic Syndromes

“…Possibly, platelet abnormalities may reflect dysplasia of megakaryocytes and can therefore be used as a substitute [21]. Sandes et al [23] compared peripheral blood platelets in MDS (n = 44) with healthy controls thereby demon- strating differences in scatter, expression of CD34, CD36, CD42a and CD61. These findings have to be extensively validated due to confounders such as activation and inflammation before implementation in routine practice.…”

Platelet parameters and expression of platelet membrane glycoprotein in childhood acute lymphoblastic leukemia

“…In fact, Psaila et al (2011) discovered a decrease in the expression of activationrelated receptors (GP IIb/IIIa, CD62p, and GP Ib) on the surface of platelets obtained from acute myeloid leukemia or myelodysplastic syndromes (MDS) patients, as well as lower intrinsic activity and intrinsic platelet reactivity, compared to the corresponding values in samples obtained from idiopathic thrombocytopenic purpura patients. Sandes et al (2012) used flow cytometry to detect the MDS platelet phenotype, and discovered changes in the platelet phenotype in a majority of the MDS patients. The results also indicated a lower expression of CD62p and PAC-1 in the ALL group after ADP activation; additionally, the levels of CD62p returned to normal during remission, while that of PAC-1 did not.…”