SEARCH:   Advanced

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Zwaginga, J. J. Articles by Sixma, J. J. Search for Related Content PubMed PubMed Citation Articles by Zwaginga, J. J. Articles by Sixma, J. J. Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  High von Willebrand factor concentration compensates a relative adhesion defect in uremic blood JJ Zwaginga, MJ Ijsseldijk, N Beeser-Visser, PG de Groot, J Vos and JJ Sixma Department of Hematology, University Hospital, Utrecht, The Netherlands. Uremia is associated with a bleeding diathesis. We investigated platelet adhesion as a cause for the impaired primary hemostasis and the role of von Willebrand factor (vWF) in this process in uremic patients. Perfusions with blood with standardized hematocrit, platelet count, and free Ca2+ ions were performed over inverted and deendothelialized artery segments from human umbilical cords in a modified Baumgartner perfusion chamber. Platelet adhesion in patient perfusates was comparable with control adhesion. However, the high vWF levels present in uremic whole blood did not increase adhesion above the adhesion in control blood with lower vWF levels. These results suggested that a relative adhesion defect was present in patient blood. Control blood in which vWF levels were raised to uremic levels showed the high adhesion that uremic whole blood failed to show. Additionally, in perfusions with uremic plasma in which the initially high vWF level was normalized by dilution with vWF-depleted uremic plasma, adhesion was clearly lower than in normal plasma. Washed patient platelets did not differ from normal platelets in their association with purified vWF, via their adhesion receptors glycoprotein Ib and IIb-IIIa. Patient platelets present in patient plasma showed a similar adhesion defect as control platelets, which were resuspended in the uremic plasma. Therefore, primary defects of uremic platelets were of minor importance for the observed adhesion defect in uremic whole blood. The adhesion defect was not dependent on the presence of uremic vWF; plasma of uremic patients depleted of vWF also inhibited adhesion, and the defect remained present when purified control vWF was added to vWF-depleted uremic plasma. The binding of uremic vWF to the vessel wall and its support of subsequent adhesion were not impaired. These results indicate that the observed adhesion defect was not due to abnormal vWF. Our current results suggest an unknown component present in uremic plasma that directly inhibits platelet interaction with artery segments; however, it has no effect on vWF binding to the vessel wall. High vWF levels in uremic plasma are able to compensate for the defect. Volume 75, Issue 7, pp. 1498-1508, 04/01/1990 Copyright © 1990 by The American Society of Hematology CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: A. Casonato, E. Pontara, U.P. Vertolli, A. Steffan, C. Durante, L. De Marco, F. Sartorello, and A. Girolami Plasma and Platelet von Willebrand Factor Abnormalities in Patients With Uremia: Lack of Correlation With Uremic Bleeding Clinical and Applied Thrombosis/Hemostasis, April 1, 2001; 7(2): 81 - 86. [Abstract] [PDF]

	Copyright © 1990 by American Society of Hematology         Online ISSN: 1528-0020