title: Platelet aggregation and pseudothrombocytopenia induced by 1-desamino-8-D-arginine vasopressin (DDAVP) in type IIB von Willebrand's disease patient.
abstract: Our study shows that the thrombocytopenia described in type IIB von Willebrand's disease (vWd) after 1-desamino-8-D-arginine vasopressin (DDAVP) infusion is, at least partially, a pseudothrombocytopenia. There was a discrepancy in platelet counts in blood anticoagulated with EDTA (less than 10 x 10(3)/microliters) or citrate (55 x 10(3)/microliters) in one patient with type IIB vWd and chronic thrombocytopenia (80 x 10(3)/microliters) after DDAVP infusion. Furthermore, DDAVP induced a normalization of patient's prolonged bleeding time. Spontaneous platelet aggregation (SPA) observed in platelet-rich plasma before DDAVP infusion was inhibited completely by monoclonal antibodies which block binding of fibrinogen, vWf and fibronectin to GPIIb-IIIa. SPA was partially inhibited by a monoclonal antibody which blocks the binding of vWf to GPIb. After DDAVP, in contrast, SPA partially persisted in the presence of anti-GPIIb-IIIa monoclonal antibodies but was completely inhibited by anti-GPIb monoclonal antibody. Therefore GPIb and GPIIb-IIIa complex seem to play a different role in SPA before and after DDAVP infusion into type IIB vWd.
authors.affiliation: University of Padua Medical School, Institute of Medical Semeiotics, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Casonato
authors.forename: F
authors.initials: F
authors.lastname: Fabris
authors.forename: A
authors.initials: A
authors.lastname: Girolami
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000925:Anticoagulants; D001760:Bleeding Time; D001792:Blood Platelets / Q000276:immunology; D002951:Citrates; D019343:Citric Acid; D003894:Deamino Arginine Vasopressin / Q000009:adverse effects* / Q000494:pharmacology; D004492:Edetic Acid; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D013921:Thrombocytopenia / Q000139:chemically induced*; D014842:von Willebrand Diseases / Q000097:blood*; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000925:Anticoagulants; D002951:Citrates; D046911:Macromolecular Substances; D014841:von Willebrand Factor; D019343:Citric Acid; D004492:Edetic Acid; D003894:Deamino Arginine Vasopressin