Platelet‐function Studies in the Bernard‐soulier Syndrome*

104

A B S T R A C T Treatment of human platelets with purified bovine Factor VIII caused three types of aggregation: (a) primary agglutination; (b) secondary aggregation involving the platelet release reaction; and (c) super-aggregation, in which the platelets were gathered into only a few large clumps. Removal of calcium ions or treatment with p-hydroxymercuriphenyl sulfonate blocked the release reaction, but not primary agglutination or super-aggregation. Platelets treated with formalin were not aggregated by ADP, thrombin, or collagen, but were agglutinated by bovine Factor VIII, although they did not show super-aggregation. Formalin-treated platelets were agglutinated by phytohemagglutinin P less extensively and less rapidly than by bovine Factor VIII. Treatment of platelets and Factor VIII with neuraminidase released 60 and 53%, respectively, of the sialic acid residues without affecting the agglutination reaction or the procoagulant activity of the Factor VIII. Agglutination was inhibited by high salt concentrations, dextran sulfate, and heparin. During agglutination, both the procoagulant and platelet-agglutinating activities of Factor VIII became bound to the platelet surface.

Section: Resultsmentioning

confidence: 99%

“…Aggregation can be restored by the addition of purified human Factor VIII (9), but not by other plasma components. Platelets from patients with Bernard-Soulier syndrome are not aggregated by ristocetin (10) or by bovine Factor VIII (11).…”

Section: Introductionmentioning

confidence: 99%

The interaction of bovine factor VIII with human platelets.

Kirby¹,

Mills²

1975

104

“…Bovine von Willebrand factor, the active agent in bovine fibrinogen preparations (30,31), agglutinates normal but not Bernard-Soulier platelets (32). Agglutination by bovine von Willebrand factor has many features in common with agglutination by the combination of human von Willebrand and ristocetin (8,(10)(11)(12)(13)).…”

Section: Discussionmentioning

confidence: 99%

The Effects of Ristocetin and von Willebrand Factor on Platelet Electrophoretic Mobility

Coller¹

1978

“…Subsequent studies have suggested that the bleeding tendency arises from an abnormality in the platelet-vessel wall interaction, or more specifically, in a diminished platelet ability to adhere to subendothelium (2)(3)(4). B-S platelets are not agglutinated by bovine factor VIII (5,6) or by ristocetin in the presence of normal human plasma (7,8). A diminished binding of certain coagulation factors to B-S platelets has been noted (6) whereas a reduced binding of 125I-labeled thrombin to B-S platelets was correlated with a decreased aggregation response specifically observed with this stimulus (9,10).…”

Section: Introductionmentioning

confidence: 98%

Analysis of the glycoprotein and protein composition of Bernard-Soulier platelets by single and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Nurden¹,

Dupuis²,

Kunicki³

et al. 1981

147

A B S T R A C T Previous reports have described conflicting results concerning the glycoprotein (GP) and protein composition of Bernard-Soulier platelets. In view of this controversy we have analyzed the platelets of four Bernard-Soulier patients using improved single and two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis procedures. An absence of staining for carbohydrate of membrane GP lb was characteristic for the platelets of each patient. Major periodate-Schiff staining bands corresponding to membrane GP lIb, Illa, and IlIb were clearly detected and their presence was confirmed by two-dimensional SDS-polyacrylamide gel electrophoresis. The protein content of the Bernard-Soulier platelets was increased two-to fourfold. However, analysis of their protein composition using 7-12% acrylamide gradient gels showed normal polypeptide profiles. Lactoperoxidase-catalyzed 125I-labeling of the Bernard-Soulier platelet surface proteins was followed by SDS-polyacrylamide gel electrophoresis and autoradiography. No labeling in the Ib position was detected whereas the other major membrane GP, including Ia and Ila, were normally located. In contrast, GP lb was clearly detected by periodate-Schiff staining and autoradiography when normal human platelets that had been exhaustively treated with neuraminidase before the lactoperoxidase-catalyzed iodination were analysed. No abnormalities were detected in the GP patterns of membranes isolated from the patients' erythrocytes. Only a severe molecular abnormality or possible deletion of GP lb could account for this major platelet lesion in the Bernard-Soulier syndrome.