title: In vitro comparison between gamma-irradiated cryopreserved and Day 7 liquid-stored buffy coat-derived platelet components.
abstract: BACKGROUND
  Cryopreserved platelet (PLT) components stored at -80°C in 5% to 6% dimethyl sulfoxide (DMSO) demonstrate enhanced hemostatic activity. Alterations in PLT surface glycoprotein expression and release of procoagulant microparticles during the freeze/thaw cycle result in PLT activation. Nothing is known of the effect of gamma irradiation on the in vitro quality of reconstituted cryopreserved PLTs.
  
  
  METHODS
  Gamma-irradiated (25-50 Gy) buffy coat-derived PLT components were either stored at room temperature for 7 days (the current expiry in New Zealand) or cryopreserved at -80°C using 5% to 6% DMSO. Cryopreserved PLTs were thawed at 37°C and reconstituted in ABO-identical plasma or PAS-E and compared to Day 7 gamma-irradiated liquid-stored PLTs. In vitro assays were performed to assess glycoprotein expression, PLT functionality and soluble cytokine release.
  
  
  RESULTS
  Cryopreserved PLTs after thawing and reconstitution in ABO-matched plasma or PAS-E displayed differing recoveries (82.7 and 75.9%, respectively). Key expression levels of glycoproteins GPIbα (CD42b) and GPIIb (CD41a) were reduced. Cryopreserved PLTs retained the ability to form an effective functional clot, while showing accelerated initiation of clot formation (R-time) compared to Day 7 gamma-irradiated liquid-stored PLTs.
  
  
  CONCLUSIONS
  Gamma-irradiated buffy coat-derived liquid-stored and cryopreserved PLTs have distinctly differing phenotypes. Cryopreserved PLTs reconstituted in ABO plasma have enhanced clot strength driven by coagulation factors and fibrinogen levels not present in PAS-E. Irradiated cryopreserved PLTs maintain a similar in vitro quality profile and hemostatic behavior to previously published, nonirradiated cryopreserved PLTs.
authors.affiliation: Clinical Components Development, New Zealand Blood Service, Auckland, New Zealand.
authors.forename: Daryl
authors.initials: D
authors.lastname: Crimmins
authors.affiliation: Clinical Components Development, New Zealand Blood Service, Auckland, New Zealand.
authors.forename: Peter
authors.initials: P
authors.lastname: Flanagan
authors.affiliation: Clinical Components Development, New Zealand Blood Service, Auckland, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Charlewood
authors.affiliation: Department of Statistics, University of Auckland, Auckland, New Zealand.
authors.forename: Katya
authors.initials: K
authors.lastname: Ruggiero
mesh_terms: D000017:ABO Blood-Group System; D058621:Blood Buffy Coat / Q000528:radiation effects; D001792:Blood Platelets / Q000528:radiation effects*; D001793:Blood Preservation / Q000379:methods* / Q000592:standards; D015925:Cryopreservation / Q000379:methods / Q000592:standards; D005720:Gamma Rays; D006801:Humans; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism; D040201:Platelet Membrane Glycoprotein IIb / Q000378:metabolism; D013696:Temperature
chemical_list: D000017:ABO Blood-Group System; D019038:Platelet Glycoprotein GPIb-IX Complex; D040201:Platelet Membrane Glycoprotein IIb