title: Evaluation of the PFA-100 system in the diagnosis and therapeutic monitoring of patients with von Willebrand disease.
abstract: We have evaluated platelet function at high shear with the PFA-100 system in different subtypes of von Willebrand disease (vWD), before and after the intravenous infusions of desmopressin or a factor-VIII/von Willebrand factor (vWF) concentrate. Closure times with the PFA-100 system were determined for both the collagen/ADP and the collagen/epinephrine cartridges in 52 patients with vWD (9 type 1 "platelet normal", 5 type 1 "platelet-discordant", 8 type 1 "platelet-low", 6 type 2A, 9 type 2B, 6 type 2M Vicenza. 6 type 3 and 3 acquired vWD) and 40 controls. Measurements were repeated 1 and 4 h after the i.v. infusion of desmopressin (0.3 microg/Kg) in 26 patients with types 1, type 2M Vicenza or type 2A vWD, or of a factorVIII/vWF concentrate (Alphanate HT, 60 U/Kg) in 4 patients with type 3 vWD. At all time points, vWF plasma levels and the bleeding time (Symplate II) were also determined. Baseline closure times were longer in vWD patients than in controls with both the collagen/ADP and the collagen/ epinephrine cartridges. The sensitivity of the PFA-100 system (88% and 87% with the two cartridges) was higher than that of the bleeding time (65%). Treatment with desmopressin normalized the closure times in patients with type 1 "platelet-normal" or type 2M Vicenza vWD, had no significant effects in patients with type 1 "platelet-low", type 1 "platelet-discordant" or type 2A vWD. Infusion of a factorVIII/vWF concentrate in patients with type 3 vWD slightly shortened their prolonged closure times. In general, changes in PFA-100 were paralleled by shortenings of the bleeding times and increases in plasma vWF levels. The PFA-100 test reflects vWF-dependent platelet function under high shear stress and could be useful in the diagnosis and therapeutic monitoring of patients with vWD.
authors.affiliation: Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University of Milano, Italy. marco.cattaneo@unimi.it
authors.forename: M
authors.initials: M
authors.lastname: Cattaneo
authors.forename: A B
authors.initials: AB
authors.lastname: Federici
authors.forename: A
authors.initials: A
authors.lastname: Lecchi
authors.forename: B
authors.initials: B
authors.lastname: Agati
authors.forename: R
authors.initials: R
authors.lastname: Lombardi
authors.forename: F
authors.initials: F
authors.lastname: Stabile
authors.forename: P
authors.initials: P
authors.lastname: Bucciarelli
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D003894:Deamino Arginine Vasopressin / Q000008:administration & dosage; D004864:Equipment and Supplies; D006490:Hemostatics / Q000008:administration & dosage; D006801:Humans; D007262:Infusions, Intravenous; D015539:Platelet Activation; D014842:von Willebrand Diseases / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology; D014841:von Willebrand Factor / Q000008:administration & dosage
chemical_list: D006490:Hemostatics; D014841:von Willebrand Factor; D003894:Deamino Arginine Vasopressin