[Platelet defects in chronic myeloproliferative disorders].

Platelet abnormalities are common in patients with chronic myeloproliferative disorders. In this study we report abnormalities in platelets morphology and function in 45 patients with chronic myeloproliferative disorders: 15 with chronic myelogenous leukaemia (CML), 8 with polycythemia rubra vera (PRV), 20 with essential thrombocythemia, and 2 with myelofibrosis (ME). We investigated flow cytometric features of platelets as measured with Technicon H1 technology, VIZ, mean platelet volume (MPV), plateletocrit), platelet distribution width (PDW), and modal platelet volume (PLT Mode) Platelet aggregation in response to ADP, epinephrine and collagen was used as functional test. In patients with ET, PRV and MF we found a significant decrease in platelet volume (both MPV and PLT MODE). Decrease in platelet aggregation and secretion in response to ADP, epinephrine and collagen was the most frequent abnormality in platelets function and was observed in most of patients with thrombocythemia in chronic myeloproliferative disorders.