title: Prolonged circulation of activated platelets following plasmapheresis.
abstract: The extent and duration of in vivo platelet activation were determined in 12 volunteer donors undergoing automated plasmapheresis. Expression of P-selectin, activated GpIIb/IIIa, and platelet microparticle formation were measured by flow cytometry on peripheral blood samples obtained immediately before and after plasmapheresis and at 24 hour intervals thereafter for up to 3 days. Although no adverse effects were noted in any donor, immediately after apheresis 3-87% of circulating platelets expressed P-selectin; by 48 hours, 0.5-50% expressed P-selectin; and by 72 hours, all donors studied had fewer than 5% P-selectin expression on circulating platelets. Results were similar for the expression of the activated conformation of GpIIb/IIIa. There was a positive correlation with in vitro P-selectin expression in response to ADP in the pre-apheresis sample and the number of platelet microparticles detected in the donor following plasmapheresis. In addition, the percent expression of P-selectin and activated GpIIb/IIIa in response to ADP was reproducible in each individual studied on five separate occasions (CV < or = 8%). Platelets activated during plasmapheresis using an automated device may circulate for at least 48 hours, and pre-plasmapheresis response of platelets to the agonist ADP correlated with platelet microparticle formation post-plasmapheresis.
authors.affiliation: University of California-Davis Medical Center.
authors.forename: T
authors.initials: T
authors.lastname: Wun
authors.forename: T
authors.initials: T
authors.lastname: Paglieroni
authors.forename: P
authors.initials: P
authors.lastname: Holland
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D000818:Animals; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D019007:P-Selectin; D010956:Plasmapheresis; D015539:Platelet Activation; D010980:Platelet Membrane Glycoproteins / Q000032:analysis
chemical_list: D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D000244:Adenosine Diphosphate