Platelet Functional Defects in Thrombocytopenic Purpura

A defect in a serum thromboplastic component was found in six patients with severe thrombocytopenic purpura in addition to the platelet thromboplastic defect.

The defective sera returned to normal spontaneously upon storage at -20 C. The addition of washed normal platelets during coagulation completely corrected the serum defect in the one instance in which it was possible to carry out the experiment.

It was postulated that a platelet factor was primarily at fault, resulting in the lack of immediate activation of a serum thromboplastic component.

The two thromboplastic defects are cumulative and are possibly dependent upon separate platelet factors.