title: Release of potential immunomodulatory factors during platelet storage.
abstract: BACKGROUND
  Blood platelets (PLTs) link the processes of hemostasis and inflammation. Recent studies have demonstrated that PLTs promote immunity and inflammation mainly by means of the CD40/CD40L pathway. Our objective was to describe the accumulation of cytokines in PLT concentrates during storage.
  
  
  METHODS
  Pools of PLT concentrates were prepared, separated from plasma, and resuspended in clinical-grade storage medium; samples were taken on Days 0, 1, 2, 3, and 5 for analysis, without replacement (i.e., without soluble protein dilution). Interleukin (IL)-6, IL-8, PLT-derived growth factor (PDGF)-AA, soluble CD40 ligand (sCD40L), RANTES, and transforming growth factor-beta production were measured by specific enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Over time, the levels of RANTES, IL-8, and IL-6 were stable. In contrast, the levels of PDGF-AA and sCD40L increased. Ex vivo production of sCD40L was quantified at levels sufficient to induce B-cell effects based on previous studies of in vitro induced B-cell activation and differentiation by sCD40L. Cytokine and/or chemokine levels were generally higher in PLT concentrate supernatants and/or PLT lysates in comparison to PLT-free plasma, allowing the determination of which cytokine and/or chemokine was absorbed or secreted by transfusion-grade PLTs over time.
  
  
  CONCLUSIONS
  Our data provide evidence that stored PLTs contain molecules with known immunomodulatory competence and secrete them differentially over time during storage for transfusion purposes.
authors.affiliation: EFS Auvergne-Loire, Saint-Etienne, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Cognasse
authors.forename: Françoise
authors.initials: F
authors.lastname: Boussoulade
authors.forename: Patricia
authors.initials: P
authors.lastname: Chavarin
authors.forename: Sophie
authors.initials: S
authors.lastname: Acquart
authors.forename: Patrick
authors.initials: P
authors.lastname: Fabrigli
authors.forename: Bernard
authors.initials: B
authors.lastname: Lamy
authors.forename: Olivier
authors.initials: O
authors.lastname: Garraud
mesh_terms: D001792:Blood Platelets / Q000276:immunology* / Q000378:metabolism; D001793:Blood Preservation; D023201:CD40 Ligand / Q000032:analysis; D018946:Chemokine CCL5 / Q000032:analysis; D016238:Cytapheresis; D016207:Cytokines / Q000032:analysis; D006801:Humans; D007155:Immunologic Factors / Q000378:metabolism*; D007378:Interleukins / Q000032:analysis; D017713:Platelet Transfusion / Q000379:methods / Q000592:standards; D010982:Platelet-Derived Growth Factor / Q000032:analysis; D013997:Time Factors
chemical_list: D018946:Chemokine CCL5; D016207:Cytokines; D007155:Immunologic Factors; D007378:Interleukins; D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A; D023201:CD40 Ligand