title: Hemolink, an o-raffinose cross-linked haemoglobin-based oxygen carrier, does not affect activation and function of human platelets in whole blood in vitro.
abstract: Haemoglobin-based oxygen carriers (HBOCs) are anticipated to be safe and efficient alternatives to RBC transfusions. Haemoglobin (Hb) raffimer (Hemolink; Hemosol, Toronto, ON, Canada) is polymerized human Hb, cross-linked with o-raffinose. As administration of cell-free Hb may affect blood cells and tissues, this study was focused on evaluating effects of Hb raffimer on human platelets in whole blood in vitro. Citrated blood from healthy donors was incubated with Hb raffimer to achieve raffimer concentrations of 2-50 vol percentage (2-50 g/l). Platelet activation, phosphatidylserine exposure and microparticle generation were measured by flow cytometry. Aperture closure time on collagen/ADP- and collagen/epinephrine-coated membranes was determined by a platelet function analyser (PFA-100). We found that addition of Hb raffimer to blood samples up to 50 vol % did not affect human platelets as measured by various markers of platelet activation (CD42b, CD41, PAC-1, CD62, CD63), procoagulant activity (annexin V) and microparticle formation; differences between Hb raffimer- and lactated Ringer's-diluted blood were not significant. Similarly, no adverse effect of Hb raffimer on closure time was observed at concentrations up to 50 vol %, in comparison with Ringer's solution. These data indicate that exposure of human blood to high concentrations of Hb raffimer in vitro did not cause platelet activation nor affect platelet function.
authors.affiliation: Department of Transfusion Medicine, St. Michael's Hospital, Toronto, Canada.
authors.forename: Valery
authors.initials: V
authors.lastname: Leytin
authors.forename: David
authors.initials: D
authors.lastname: Mazer
authors.forename: Meera
authors.initials: M
authors.lastname: Mody
authors.forename: Bernadette
authors.initials: B
authors.lastname: Garvey
authors.forename: John
authors.initials: J
authors.lastname: Freedman
mesh_terms: D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D001802:Blood Substitutes / Q000494:pharmacology*; D005434:Flow Cytometry; D006454:Hemoglobins / Q000494:pharmacology*; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D015539:Platelet Activation / Q000187:drug effects*; D010979:Platelet Function Tests; D011887:Raffinose / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; C097124:O-raffinose cross-linked human hemoglobin; D011887:Raffinose