title: Platelet adhesion changes during storage studied with a novel method using flow cytometry and protein-coated beads.
abstract: The aim of the present study was to set up and evaluate a novel method for studies of platelet adhesion and activation in blood and platelet suspensions such as platelet concentrate (PC) samples using protein-coated polystyrene beads and flow cytometry. To demonstrate its usefulness, we studied PCs during storage. PCs were prepared by aphaeresis technique (n = 7). Metabolic variables and platelet function was measured on day 1, 5, 7 and 12 of storage. Spontaneous and TRAP-6-induced adhesion to fibrinogen- and collagen-coated beads was analyzed by flow cytometry. P-selectin and phosphatidyl serine (PS) expression was assessed on platelets bound to beads as well as on non-adherent platelets. Platelet adhesion to fibrinogen beads had increased by day 12 and adhesion to collagen beads at day 7 of storage (p < 0.05). TRAP-6 stimulation significantly increased the platelet adhesion to fibrinogen beads (p < 0.05) as well as the P-selectin and PS exposure on platelets bound to beads (p < 0.01) during the first 7 days of storage, but by day 12, significant changes were no longer induced by TRAP-6 stimulation. We demonstrate that our adhesion assay using protein-coated polystyrene beads can be used to assess the adhesion properties of platelets during storage without the addition of red blood cells. Therefore it may offer a useful tool for future studies of platelet adhesive capacity in transfusion medicine and other settings.
authors.affiliation: Department of Clinical and Experimental Medicine, Division of Transfusion Medicine, Faculty of Health Sciences, Linköping University , Linköping , Sweden .
authors.forename: Nahreen
authors.initials: N
authors.lastname: Tynngård
authors.forename: Maria
authors.initials: M
authors.lastname: Wallstedt
authors.forename: Anna L
authors.initials: AL
authors.lastname: Södergren
authors.forename: Lars
authors.initials: L
authors.lastname: Faxälv
authors.forename: Sofia
authors.initials: S
authors.lastname: Ramström
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D001793:Blood Preservation; D002470:Cell Survival; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D019007:P-Selectin / Q000378:metabolism; D015539:Platelet Activation; D010973:Platelet Adhesiveness; D010974:Platelet Aggregation; D010979:Platelet Function Tests; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D019007:P-Selectin; D019038:Platelet Glycoprotein GPIb-IX Complex; C094990:adhesion receptor
keywords: Adhesion molecules; blood products; platelet glycoproteins; transfusion medicine