Summary
Biochemistry, function, and hemostatic effectiveness of human platelets preserved by freezing with 5% DMSO (1, 2) were studied. Determination of platelet glycogen, β-glucuronidase (a lysosomal enzyme), and purine nucleoside phosphorylase (a cytoplasmic enzyme) showed that freezing and thawing caused a complex cell lesion. Hemostatic effectiveness of the frozen platelets was measured from the shortening of the bleeding time (template method) upon infusion of the platelets in patients with severe and stable thrombocytopenia due to bone marrow depression. The frozen platelets produced shortening of the bleeding time to a degree almost similar to that obtained with fresh platelets; however, the bleeding time was shorter 3 hr after infusion than soon after it, while increments in platelet count were greatest immediately after infusion. This finding indicates that frozen platelets carry a functional lesion from which they can rapidly recover in the circulation.
In fact, this research demonstrates that frozen platelets are valuable in arresting hemorrhage due to thrombocytopenia.
The technical assistance of Mrs. Chul Soon Lim and Mrs. Donna Field is gratefully acknowledged.
