Reaction of blood with artificial surfaces of hemodialyzers. Studies of human blood with platelet defects or coagulation factor deficiencies.

Heparinized human blood was exposed to the dialysis membranes of commercially available pediatric size hemodialyzers in an in vitro flow circuit. Bloods from normal subjects and from patients with various blood coagulation and platelet function deficiencies were tested in this model system. In most cases, there was a heavy linear deposit of leukocytes on the dialysis membrane overlying support structures. In other areas, the cellular deposit was less uniform and consisted of single platelets, platelet aggregates, leukocytes, and occasional fibrocellular microthrombi. The number of adherent platelets was smaller in tests with blood from patients with congenital afibrinogenemia, factor XII deficiency, severe von Willebrand's disease, and thrombasthenia then in tests with blood from normal subjects or hemophilic patients. Hence, fibrinogen, factor XII, the von Willebrand factor, and a normal platelet plasma membrane appear necessary for adhesion of platelets to dialysis membranes.