Increased Platelet Surface Expression of P-Selectin and Thrombospondin as Markers of Platelet Activation in Essential Thrombocythaemia

Flow cytometry demonstrates differences in platelet reactivity and microparticle formation in subjects with thrombocytopenia or thrombocytosis due to primary haematological disorders

“…Our findings of increased Pselectin expression in unstimulated samples is consistent with that previously described for subjects with ET [14,15].…”

Absence of compensatory platelet activation in patients with severe haemophilia, but evidence for a platelet collagen-activation defect

“…The most intensely investigated receptor is P-selectin; we and many others have found an increased expression of P-selectin in a wide variety of disease states with increased thromboembolic risk. [11][12][13][14][15][16][17][18][19] Similar results have been found for CD 63 and PAC 1 expression and for thrombospondin binding. 11,16,17 Much less is known about platelet activation in response to haemorrhagic events.…”

“…[11][12][13][14][15][16][17][18][19] In animal models, raised P-selectin expression was seen following experimental haemorrhage. 20,21 Thus, these receptors seem to play an important role for effective haemostasis.…”

Hemostatic disorders in a JAK2V617F-driven mouse model of myeloproliferative neoplasm

“…28 The defective in vitro thrombosis and low responsiveness of JAK2 V617F platelets occurred simultaneously in SCLCreER t /JAK2 V617F KI mice. In PV and ET patients, platelets have been proposed to be less responsive in vitro as a consequence of their in vivo activation, 29,30 with elevated markers of platelet activation reported in some, but not all, studies on PV, 13,31 ET, 16,32,33 and PMF 13 patients. In contrast to these observations, no increased P-selectin expression was observed on platelets from VavCre/JAK2 V617F and SCLCreER t /JAK2 V617F KI mice.…”