[Hematostatic function in myeloproliferative diseases]

This study was purposed to investigate the change of early hemostatic function in patients with myeloproliferative diseases (MPD) and to explore its significance in combination with clinical data. The platelet aggregative function was measured by using ristomycin, adenosine diphosphate, collagen and adrenine as inductors, the plasma von Willebrand factor-associated antigen (vWF: Ag) level was measured by enzyme-linked immunosorbent assay (ELISA), the plasma von Wellebrand factor-ristomycin cofactor (vWF: Rco) activity was measured in 6 patients with obviously low ristomycin induced platelet aggregation (RIPA). The results showed that the platelet aggregative function obviously decreased in 35 patients, there were distinct differences in maximal platelet aggregative rate between patients and normal controls induced by 4 inductors respectively (P < 0.001, P < 0.001, P = 0.002, P < 0.001). There was no obvious difference between patients with MPD and healthy controls in plasma vWF: Ag level (P > 0.50). Plasma vWF: Rco activity in all 6 patients with MPD chosen was in the normal range, except one patient with essential thrombocytosis (ET) whose plasma vWF: Rco activity was much lower than normal. No correlation was found between platelet count and plasma vWF: Ag level in the patients (r = -0.180). No correlation was found between platelet count and maximal platelet aggregative rate induced by 4 inductors respectively in patients. It is concluded that the occurrence of abnormal platelet aggregative function is high in patients with MPD. The RIPA and vWF: Rco activity decrease in one patient with ET. However, the shortage of vWF polymer existed in his plasma have needs for further research. No correlation was observed between hemostasis and clinical manifestations. However, because of the high occurrence of platelet dysfunction in MPD patients, the clinical application of anti-platelet drugs should be considered carefully.