MEASUREMENT OF PLATELET ADHESIVENESS. A SIMPLE IN VITRO TECHNIQUE DEMONSTRATING AN ABNORMALITY IN VON WILLEBRAND'S DISEASE.

Abstract

Abstract The adhesiveness of human blood platelets has been measured by an in vitro technique which employs a short contact time and requires no anticoagulant before contact of blood with a foreign surface. Under these conditions, platelet adhesiveness is normal in disorders of blood coagulation and in patients receiving heparin but is deficient in thrombasthenia and in ion Willebrand's disease. When blood is exposed to glass, a time-consuming reaction occurs, manifested by a rise in platelet adhesiveness. This phenomenon requires calcium and is not blocked by heparin. These observations are consistent with the thesis that the initial aggregation of platelets in hemostasis is not dependent on blood coagulation.