title: Coagulation activities of plasma microparticles.
abstract: An evaluation of the effect of plasma microparticles (MP) on in vitro coagulation has been undertaken using platelet rich (PRP), platelet poor (PPP) and platelet free (PFP) plasmas prepared by differential centrifugation. MP provide coagulant material which shortens the activated partial thromboplastin time (APTT) and dilute simplastin time (DSTT) which is different from that contributed by commercial phospholipid preparations. The amount of platelet factor three (PF3) available in plasma is directly correlated with the centrifugal force used in its preparation and is present in large amounts in the MP pellet remaining after preparation of PFP. Factor VIII (F.VIII:C) and von Willebrand factor (vWf) were associated with the MP fraction but could be separated from MP on sucrose gradients. The effect of MP on the APTT was independent of the F.VIII:C/vWf and was not solely due to their PF3 content. Plasma prepared for routine coagulation assays contains MP which contribute to the APTT and DSTT and should be considered in their assessment. High speed centrifugation of plasma reduces the F.VIII:C/vWf:Ag/RCoF levels and this may contribute to losses of these proteins during preparative procedures utilising high speed centrifugation.
authors.affiliation: Department of Medicine, Monash Medical School, Prahran, Victoria, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Howard
authors.forename: M
authors.initials: M
authors.lastname: Coghlan
authors.forename: R
authors.initials: R
authors.lastname: David
authors.forename: S L
authors.initials: SL
authors.lastname: Pfueller
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001792:Blood Platelets / Q000502:physiology; D002499:Centrifugation, Density Gradient; D005260:Female; D006467:Hemophilia A / Q000097:blood; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010316:Particle Size; D010977:Platelet Factor 3 / Q000032:analysis; D014842:von Willebrand Diseases / Q000097:blood
chemical_list: D010977:Platelet Factor 3