title: Variables influencing Platelet Function Analyzer-100 closure times in healthy individuals.
abstract: We investigated the relationship between platelet function analyzer (PFA-100) closure times (CT) and bleeding time (BT), platelet aggregation (PA) induced by ADP, arachidonic acid, and collagen, blood cell counts, and von Willebrand factor (VWF) in 120 well-characterised healthy individuals. Pre-analytical and analytical conditions were standardised comprehensively. In a substantial number of cases the differences between duplicate measurements exceeded 15%. The reference range (5th and 95th percentiles) for CT with the collagen/epinephrine (CEPI) and the collagen/ADP (CADP) cartridge was 93-223 s and 64-117 s respectively. Re-examination of 11 individuals with CEPI-CT above the 95th percentile revealed considerable batch-to-batch variation of CEPI-CT. Males had significantly longer CADP than females (P = 0.002). CEPI and CADP-CT measured pm were significantly longer than corresponding values determined am (P = 0.003 and P < 0.0001 respectively). Blood group O was associated with greater CEPI and CADP-CT and lower VWF levels compared with non-O blood groups (P = 0.008, P = 0.0003 and P < 0.0001 respectively). Linear regression analysis revealed association between CEPI-CT, CADP-CT and VWF (P < 0.0001), but no relationship was found between CT and BT or between CT and PA. We conclude that VWF plasma levels modulate PFA-100 CT to a greater extent than platelet function. Establishment of reliable reference ranges and careful standardisation of pre-analytical and analytical conditions is a prerequisite for obtaining reliable PFA-100 results. Duplicate measurements are necessary.
authors.affiliation: Institute of Hemostaseology and Transfusion Medicine, Academic City Hospital, Ludwigshafen, Germany.
authors.forename: Hannelore
authors.initials: H
authors.lastname: Haubelt
authors.forename: Christof
authors.initials: C
authors.lastname: Anders
authors.forename: Anette
authors.initials: A
authors.lastname: Vogt
authors.forename: Petra
authors.initials: P
authors.lastname: Hoerdt
authors.forename: Ulrich Theo
authors.initials: UT
authors.lastname: Seyfert
authors.forename: Peter
authors.initials: P
authors.lastname: Hellstern
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D016718:Arachidonic Acid / Q000494:pharmacology; D001760:Bleeding Time; D001782:Blood Donors; D001800:Blood Specimen Collection; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006487:Hemostasis; D006801:Humans; D016014:Linear Models; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010974:Platelet Aggregation; D010979:Platelet Function Tests / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D018709:Statistics, Nonparametric
chemical_list: D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D003094:Collagen