Spontaneous platelet aggregation in type IIB Tampa von Willebrand disease is inhibited by the 52/48-kDa fragment of normal von Willebrand factor, which contains the GPIb binding domain.

Abstract

The association of Type IIB von Willebrand disease (vWD) with chronic persistent thrombocytopenia and spontaneous platelet aggregation has recently been recognized. It has been shown that IIB von Willebrand factor (vWF) can initiate platelet aggregation by binding to the platelet glycoprotein (GP) lb receptor and inducing exposure of the GpIIb/IIIa fibrinogen receptor. In this study we demonstrate the increased binding of Type IIB Tampa vWF with normal platelets when compared with nonthrombocytopenic Type IIB vWF. Studies further demonstrate that spontaneous platelet aggregation initiated by IIB Tampa vWF can be blocked by a 52/48-kDa fragment of normal vWF, which contains the binding domain.

• Authors: H I Saba, Y Fujimura, S R Saba, A C Bruce, G A Morelli, Z M Ruggeri, T S Zimmerman
• Journal: American journal of hematology (Am J Hematol) Vol. 30 Issue 3 Pg. 150-3 (Mar 1989) ISSN: 0361-8609 [Print] United States
• PMID: 2783833 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Immunoglobulin Fragments
• Platelet Membrane Glycoproteins
• von Willebrand Factor

Topics

• Binding Sites
• Humans
• Immunoglobulin Fragments (physiology)
• Platelet Aggregation
• Platelet Membrane Glycoproteins (physiology)
• von Willebrand Diseases (blood, physiopathology)
• von Willebrand Factor (physiology)