Platelet von Willebrand Factor: An Important Determinant of the Bleeding Time in Type I von Willebrand’s Disease

• Published in: Blood Vol. 68; no. 1; pp. 58 - 61
• Main Authors: Gralnick, Harvey R., Rick, Margaret E., McKeown, Laurie P., Williams, Sybil B., Parker, Robert I., Maisonneuve, Pascal, Jenneau, Christine, Sultan, Yvette
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 01-07-1986; The Americain Society of Hematology
• Subjects: Biological and medical sciences; Bleeding Time; Blood Platelets - analysis; Electrophoresis, Agar Gel; Hematologic and hematopoietic diseases; Humans; Medical sciences; Platelet diseases and coagulopathies; von Willebrand Diseases - blood; von Willebrand Diseases - genetics; von Willebrand Factor - analysis; Hemopathy; Bleeding time; Willebrand factor; Willebrand disease; Coagulopathy
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V68.1.58.58

We studied 17 patients with moderate to mild type I von Willebrand's disease (vWd) and correlated the bleeding time with the plasma von Willebrand factor antigen (vWf Ag), the plasma vWf activity (ristocetin cofactor), the platelet vWf Ag, and the platelet vWf activity. We found an excellent correlation between the bleeding time and the platelet vWf activity and, to a lesser extent, between the bleeding time and the platelet vWf Ag. The length of the bleeding time was inversely proportional to the level of the platelet vWf (P < .001) or, to a lesser extent, the platelet vWf Ag (P < .05). The plasma vWf Ag and activity did not correlate significantly with the bleeding time. These studies indicate that the platelet vWf is one of the important bleeding time factors in type I vWd and that the platelet vWf plays an important role in the early steps of hemostasis. © 1986 by Grune & Stratton, Inc.