title: Adhesion, spreading, and aggregation of platelets in flowing blood and the reliability of the retention test Homburg.
abstract: Adhesion and aggregation are important parameters characterizing the function of intact platelets in flowing blood and in contact with a more or less thrombogenic surface. In the retention test Homburg (RTH), platelets are exposed to a standardized textured surface (Sysmex retention tubes) under defined conditions of flow. Platelet counts are performed before and after the Sysmex retention tube passage. The difference between these values indicates the percentage of retained platelets (retention index). Decreased retention in the RTH indicates a loss of function or defective platelet function; increase is associated with an increased activation of platelets, for example, in patients with vascular diseases. For further evaluation of the retention phenomenon the filters were fixed after cell passage and examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM micrographs show activated platelets adhering and spreading on the filter surface, comparable with platelets on a disturbed endothelium. Also, we examined the influence of different G forces and centrifugation times on the retention behavior of the platelets in citrated platelet-rich plasma (PRP) and whole blood (WB). G forces influenced the retention index in PRP and WB significantly and in a different way. Finally, we used a platelet standard, as customary in the quality check, to determine the serial as well as the day-to-day precision.
authors.affiliation: Professor, Department of Neurosurgery, Philipps University Marburg, Germany. krischek@med.uni-marburg.de.
authors.forename: Boris
authors.initials: B
authors.lastname: Krischek
authors.forename: Eberhard
authors.initials: E
authors.lastname: Morgenstern
authors.forename: Pedres
authors.initials: P
authors.lastname: Mestres
authors.forename: Ute
authors.initials: U
authors.lastname: Klinkhardt
authors.forename: Werner
authors.initials: W
authors.lastname: Brannath
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wieding
authors.forename: Amah
authors.initials: A
authors.lastname: Nemeh
authors.forename: Walter
authors.initials: W
authors.lastname: Heinrich
authors.forename: Jochen
authors.initials: J
authors.lastname: Schenk
authors.forename: Thomas
authors.initials: T
authors.lastname: Wenzel
authors.forename: Ernst
authors.initials: E
authors.lastname: Wenzel
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001792:Blood Platelets / Q000166:cytology* / Q000648:ultrastructure*; D002498:Centrifugation; D004730:Endothelium, Vascular / Q000166:cytology; D006801:Humans; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010973:Platelet Adhesiveness; D010974:Platelet Aggregation; D010976:Platelet Count; D010979:Platelet Function Tests / Q000379:methods*; D011786:Quality Control; D012016:Reference Values
chemical_list: D001672:Biocompatible Materials