title: Apheresis donors and platelet function: inherent platelet responsiveness influences platelet quality.
abstract: BACKGROUND
  Process-induced platelet (PLT) activation occurs with all production methods, including apheresis. Recent studies have highlighted the range and consistence of interindividual variation in the PLT response, but little is known about the contribution of a donors' inherent PLT responsiveness to the activation state of the apheresis PLTs or the effect of frequent apheresis on donors' PLTs.
  
  
  METHODS
  The relationship between the donors' PLT response on the apheresis PLTs was studied in 47 individuals selected as having PLTs with inherently low, intermediate, or high responsiveness. Whole-blood flow cytometry was used to measure PLT activation (levels of bound fibrinogen) before donation and in the apheresis PLTs. The effects of regular apheresis on the activation status of donors' PLTs were studied by comparing the in vivo activation status of PLTs from apheresis (n = 349) and whole-blood donors (n = 157), before donation. The effect of apheresis per se on PLT activation was measured in 10 apheresis donors before and after donation.
  
  
  RESULTS
  The level of PLT activation in the apheresis packs was generally higher than in the donor, and the most activated PLTs were from high-responder donors. There was no significant difference in PLT activation before donation between the apheresis and whole-blood donors (p = 0.697), and there was no consistent evidence of activation in the donors immediately after apheresis.
  
  
  CONCLUSIONS
  The most activated apheresis PLTs were obtained from donors with more responsive PLTs. Regular apheresis, however, does not lead to PLT activation in the donors.
authors.affiliation: Department of Haematology, University of Cambridge, Cambridge, UK.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Garner
authors.forename: Chris I
authors.initials: CI
authors.lastname: Jones
authors.forename: Jonathan
authors.initials: J
authors.lastname: Stephens
authors.forename: Philippa
authors.initials: P
authors.lastname: Burns
authors.forename: Jill
authors.initials: J
authors.lastname: Walton
authors.forename: Adam
authors.initials: A
authors.lastname: Bernard
authors.forename: Will
authors.initials: W
authors.lastname: Angenent
authors.forename: Willem H
authors.initials: WH
authors.lastname: Ouwehand
authors.forename: Alison H
authors.initials: AH
authors.lastname: Goodall
mesh_terms: D000328:Adult; D001781:Blood Component Removal; D001792:Blood Platelets / Q000166:cytology / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology*