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In vitro function and phagocytosis of galactosylated platelet concentrates after long‐term refrigeration
Author(s) -
Babic Aleksandar M.,
Josefsson Emma C.,
Bergmeier Wolfgang,
Wagner Denisa D.,
Kaufman Richard M.,
Silberstein Leslie E.,
Stossel Thomas P.,
Hartwig John H.,
Hoffmeister Karin M.
Publication year - 2007
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2007.01134.x
Subject(s) - chemistry , in vitro , platelet , flow cytometry , phagocytosis , cd63 , leukapheresis , immunology , microbiology and biotechnology , biochemistry , biology , microvesicles , microrna , stem cell , gene , cd34
BACKGROUND: Short‐term refrigeration of platelets (PLTs) in the absence of plasma results in their rapid clearance after transfusion. Blocking β‐ N ‐acetylglucosamine (β‐GlcNAc) residues of glycoprotein Ibα (GPIbα) with galactose prevents binding of refrigerated human and mouse PLTs to macrophages and prolongs the circulation times of refrigerated mouse PLTs. PLT‐associated galactosyltransferase efficiently galactosylates chilled PLTs in the presence of its substrate UDP‐galactose is added to PLT‐rich plasma. STUDY DESIGN AND METHODS: To characterize the hemostatic function of refrigerated and galactosylated human PLTs processed in the blood bank, PLT aggregation was studied in vitro under static and flow conditions and expression of integrin β3 (CD61), CD62P (P‐selectin), GPIbα (CD42b), annexin V binding, and integrin αIIβ3 activation with flow cytometry. Affinity of macrophages for galactosylated refrigerated PLTs was evaluated with THP‐1 cells, which recognize and phagocytize refrigerated PLTs. RESULTS: PLTs refrigerated and galactosylated for 14 days 1) maintained their ability to aggregate when exposed to agonists in a standard aggregometry assay, 2) showed less pronounced changes in surface expression of GPIbα compared with room temperature (RT)‐stored PLTs, 3) increased P‐selectin expression, and 4) were poorly phagocytized by differentiated THP‐1 cells in vitro. In addition, it is shown that refrigeration of PLTs does not affect their adhesive properties under in vitro flow conditions. CONCLUSION: It is shown that refrigerated human PLTs retain in vitro function better than RT PLTs during storage and demonstrate that galactosylation prevents recognition of stored refrigerated PLTs by macrophages in vitro.