Authors: Margarida Coucelo Gonçalo Caetano Teresa Sevivas Susana Almeida Santos Teresa Fidalgo Celeste Bento Manuela Fortuna Marta Duarte Cristina Menezes M Letícia Ribeiro
Publish Date: 2013/11/26
Volume: 99, Issue: 1, Pages: 32-40
Abstract
The clinical courses of polycythemia vera PV and essential thrombocythemia ET are characterized by thrombohemorrhagic diathesis Several groups have suggested an association between JAK2V617F mutation and thrombosis We hypothesized a relationship between JAK2V617F allele burden cellular activation parameters and thrombosis We evaluated a group of PV and ET patients using flow cytometry platelet CD62P CD63 and dense granules platelet–leukocyte aggregates PLA leukocyte CD11b and monocyte tissue factor TF expression All patients had increased baseline platelet CD62P and CD63 expression p 005 71 of PV and 47 of ET presented with a storage pool disease Leukocyte CD11b TF and PLA were elevated in all patients TF was higher in PV compared to ET p 005 and platelet–neutrophil polymorphonuclear PMN aggregates were increased in ET versus PV p 005 In ET PLA were correlated with platelet numbers p 005 In all patients JAK2V617F allele burden was directly correlated with monocyte CD11b Patients with JAK2V617F allele burden 50 presented higher levels of leukocyte activation In ET thrombosis was associated with JAK2V617F mutation p 005 χ 2 = 52 increased monocyte CD11b p 005 and with plateletPMN aggregates p 005 In ET patients hydroxyurea does not significantly reduce the activation parameters Our data demonstrate that JAK2V617F allele burden is directly correlated with activation parameters that drive mechanisms that favor thrombosis
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