title: Impact of ABO blood groups on tirofiban mediated inhibition of platelet function.
abstract: Previous investigations revealed that ABO blood groups are associated with divergent concentrations of several coagulation factors. Concentrations of von Willebrand factor (vWF) and factor VIII are lower in individuals with blood group O as compared to subjects with blood group A, B or AB which might result in a reduced inhibition of platelet aggregation. The aim of the present in-vitro-investigation was to elucidate the impact of ABO blood group dependent vWF concentrations on tirofiban mediated inhibition of GPIIb/IIIa function. Platelet function was measured with the platelet function analyzer PFA-100 at baseline and at increasing concentrations of tirofiban and stratified for blood group O vs. A. If measured with the collagen/epinephrine cartridge, blood group O was associated with a prolonged mean baseline closure time in comparison with blood group A (175.8 +/- 64.9 s vs. 121.4 +/- 33.4 s, p = 0.037) which was paralleled by reduced concentrations of vWF and factor VIII. In contrast, no differences in closure time (227.6 +/- 76.1 s vs. 223.9 +/- 81.9 s, p = 0.96) could be found in the presence of tirofiban (0.1 microg/ml). Thus, tirofiban mediated GP IIb/IIIa receptor antagonism as determined with the PFA-100 seems to be independent on plasma concentration of vWF.
authors.affiliation: Institute of Clinical Pharmacology, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Feuring
authors.forename: J
authors.initials: J
authors.lastname: Harenberg
authors.forename: A
authors.initials: A
authors.lastname: Peiter
authors.forename: A
authors.initials: A
authors.lastname: Ganschow
authors.forename: A
authors.initials: A
authors.lastname: Ruf
authors.forename: R
authors.initials: R
authors.lastname: Losel
authors.forename: M
authors.initials: M
authors.lastname: Wehling
authors.forename: A
authors.initials: A
authors.lastname: Schultz
mesh_terms: D000017:ABO Blood-Group System / Q000502:physiology*; D000328:Adult; D000900:Anti-Bacterial Agents / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism*; D005169:Factor VIII / Q000378:metabolism; D006801:Humans; D008297:Male; D010979:Platelet Function Tests; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012310:Ristocetin / Q000378:metabolism; D000077466:Tirofiban; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D000017:ABO Blood-Group System; D000900:Anti-Bacterial Agents; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014841:von Willebrand Factor; D012310:Ristocetin; D014443:Tyrosine; D005169:Factor VIII; D000077466:Tirofiban