Analysis of rhG-CSF-effects on platelets by in vitro bleeding test and transcranial Doppler ultrasound examination

Experimental evidence suggests a stimulatory effect of recombinant human gr anulocyte colony-stimulating factor (rhG-CSF) on both platelets and coagula tion. RhG-CSF is increasingly used to stimulate healthy volunteer donors fo r blood stem cell mobilization, We therefore assessed 25 healthy donors rec eiving rhG-CSF for changes in in vitro bleeding test (IVBT), coagulation pa rameters and cerebral microembolism by transcranial Doppler (TCD) ultrasoun d. A significant shortening of IVBT was found on day 4 of rhG-CSF administr ation together with increased levels of fibrinogen and factor VIII and redu ced activities of protein C and protein S, Although these changes are quite small it is possible that they may lead to a hypercoagulable state especia lly in donors with other risk factors for thromboembolism. However, TCD exa mination failed to detect any signs of microembolism. We therefore conclude that rhG-CSF leads to significant changes in coagulation parameters, but h as no effect on TCD detectable microembolism as a stroke risk factor. Howev er donors receiving rhG-CSF should be examined carefully to detect pre-exis ting changes in the coagulation system and we would like to suggest a routi ne thrombophilia screen.