title: Effects of the addition of second-messenger effectors to platelet concentrates separated from whole-blood donations and stored at 4 degrees C or -80 degrees C.
abstract: BACKGROUND
  Platelet concentrates (PCs) are currently stored at 22 degrees C under continuous agitation. Because of the potential risk of the overgrowth of bacteria in case of contamination, PC shelf life is limited to 5 days. A mixture of second-messenger effectors is being evaluated to determine if it has benefits for cold liquid storage and cryopreservation of platelets.
  
  
  METHODS
  PCs separated from whole-blood donations by the buffy coat method were randomly assigned (n = 6 each) to be stored for 5 days at 22 degrees C under continuous agitation or at 4 degrees C after treatment with a platelet storage medium (ThromboSol, LifeCell Corp. ). PCs were also cryopreserved with 6-percent DMSO (final concentration) or with ThromboSol plus 2-percent DMSO (final concentration) (TC). After storage, platelets were analyzed by flow cytometry, transmission electron microscopy, and aggregation and perfusion techniques.
  
  
  RESULTS
  Cold liquid storage of ThromboSol-treated platelets resulted in a lower binding of coagulation factor Va on the platelet surface than on platelets stored at 22 degrees C. In transmission electron microscopy, a conversion to spherical morphology was seen in the case of cold liquid storage. No difference between ThromboSol-treated platelets stored at 4 degrees C and platelets stored at 22 degrees C was seen in perfusion studies. Cryopreservation in the presence of TC prevented the reduction in glycoprotein Ib and IV expression on platelet surface that is seen in 6-percent DMSO-cryopreserved platelets. Platelets cryopreserved in TC covered, by thrombus, a significantly greater percentage of the perfused surface after the freezing and thawing process.
  
  
  CONCLUSIONS
  ThromboSol-treated PCs separated from whole-blood donations by the buffy coat method, stored at 4 degrees C for 5 days, or cryopreserved in the presence of TC, maintained in vitro functional activity comparable to that achieved by current methods of storage, although discoid morphology was not preserved during cold liquid storage with ThromboSol.
authors.affiliation: Departments of Hemotherapy and Hemostasis and of Medicine, the August Pi i Sunyer Institute of Biomedical Research, Hospital Clinic, University of Barcelona, Spain. mlozano@clinic.ub.es
authors.forename: M
authors.initials: M
authors.lastname: Lozano
authors.forename: G
authors.initials: G
authors.lastname: Escolar
authors.forename: R
authors.initials: R
authors.lastname: Mazzara
authors.forename: J
authors.initials: J
authors.lastname: Connor
authors.forename: J G
authors.initials: JG
authors.lastname: White
authors.forename: C
authors.initials: C
authors.lastname: DeLecea
authors.forename: A
authors.initials: A
authors.lastname: Ordinas
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D001792:Blood Platelets / Q000737:chemistry / Q000166:cytology / Q000382:microbiology; D002470:Cell Survival / Q000502:physiology; D015925:Cryopreservation; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D006801:Humans; D010973:Platelet Adhesiveness / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D015290:Second Messenger Systems / Q000502:physiology*
chemical_list: D000242:Cyclic AMP; D006152:Cyclic GMP