Platelet functional defects in thrombocytopenic purpura

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

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 outthe experiment.

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

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

Submitted on December 4, 1956 Accepted on March 7, 1957