Reactivity of platelets from healthy individuals and from patients with hematologic diseases following incubation with pegylated recombinant human megakaryocyte growth and development factor in vitro

Platelets express the receptor for thrombopoietin. It is possible that thro mbopoietin modulates platelet reactivity. We examined the effect of pegylat ed recombinant human megakaryocyte growth and development factor (PEG-rHuMG DF) on platelet activation in vitro using flow cytometry. We compared sampl es from healthy individuals and from patients with various hematologic dise ases (AML, myeloma, postchemotherapy). Citrated whole blood was incubated w ith PEG-rHuMGDF (10 or 100 ng/ml), then a mild stimulus was added (0.1 U th rombin/ml). Blood from healthy individuals showed a significantly higher de gree of platelet activation (CD62p expression), microparticle generation, a nd aggregate formation after incubation with PEG-rHuMGDF+thrombin versus th rombin alone (p < 0.05). However, this difference could not be shown for pl atelets from patients with thrombocytopenia or other hematologic diseases. The use of PEG-rHuMGDF should be safe and not cause an additional risk of t hromboocclusive disease in these patients.