title: Effects of high platelet concentration in collecting and freezing dry platelets concentrates.
abstract: OBJECTIVE
  To evaluate, in vitro, the effects of collecting and cryopreserving fresh dry platelet concentrates (PCs).
  
  
  METHODS
  Standard and dry PCs were collected in the same apheresis procedure. PCs were evaluated by mean platelet volume (MPV), pH, glucose and LDH levels. Activation was examined by flow cytometry using anti-CD41, anti-CD42 and anti-CD62p monoclonal antibodies and annexin binding assay. Platelet function was assessed by aggregation using ADP, collagen and arachidonic acid as agonists. Dry PCs were compared to standard PCs and to cryopreserved dry PCs. We also compared the use of ThromboSol to 5% DMSO as cryoprotectives.
  
  
  RESULTS
  Dry PCs presented a significantly reduced pH and glucose (p<0.001), increased LDH levels and CD62p expression (p<0.001) and diminished aggregation response to ADP (p<0.001). Platelet cryopreservation was associated with platelet lysis, activation and loss of function. Dry PCs cryopreserved with TS were associated with statistically higher LDH levels (p<0.001) and a higher percentage of annexin binding (p=0.005), in addition to a lower number of CD42 positive platelets (p=0.01).
  
  
  CONCLUSIONS
  Dry PCs should be rapidly frozen after collection to avoid a fall in pH and platelet activation. 5% DMSO performed better than TS to cryopreserve dry PCs.
authors.affiliation: Hematology and Blood Transfusion Centre, Hemocentro/Unicamp, State University of Campinas, Brazil. evaldolandi@saofrancisco.edu.br
authors.forename: Evaldo Pasquini
authors.initials: EP
authors.lastname: Landi
authors.forename: Eduardo Gasparotto
authors.initials: EG
authors.lastname: Roveri
authors.forename: Margareth Castro
authors.initials: MC
authors.lastname: Ozelo
authors.forename: Joyce Maria
authors.initials: JM
authors.lastname: Annichino-Bizzacchi
authors.forename: Andreia Fernanda
authors.initials: AF
authors.lastname: Origa
authors.forename: Aparecida Ribeiro
authors.initials: AR
authors.lastname: de Carvalho Reis
authors.forename: Cármino Antonio
authors.initials: CA
authors.lastname: de Souza
authors.forename: José Francisco Comenalli
authors.initials: JF
authors.lastname: Marques
mesh_terms: D001792:Blood Platelets / Q000737:chemistry / Q000502:physiology*; D001793:Blood Preservation / Q000379:methods* / Q000592:standards; D001800:Blood Specimen Collection / Q000379:methods*; D001803:Blood Transfusion; D015925:Cryopreservation; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005612:Freeze Drying / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010983:Plateletpheresis / Q000295:instrumentation / Q000379:methods; D013696:Temperature
chemical_list: D004121:Dimethyl Sulfoxide