Studies on Platelets. IV. A Thrombocytopenic Factor in Normal Human Blood, Plasma, or Serum.

Abstract

Temporary, but significant thrombocytopenia was noted in 32 out of 36 individuals receiving compatible blood, plasma or serum from non-thrombocytopenic donors. No spontaneous bleeding manifestations, alterations of the various hemostatic mechanisms, changes in number of activity of the bone marrow megakaryocytes, alterations of function or morphology of the remaining platelets, agglutinating or lysing activity of the recipient''s serum against normal platelets were noted. Heparinization of the recipient did not affect the thrombocytopenic effect of the transfusion of compatible plasma. Expts. on 19 additional recipients demonstrated that the thrombocytopenic effect was apparently due to a component of plasma, stable at 56[degree]C, not absorbed by Seitz filters nor by ion-exchange resin, but adsorbed on Ca3(PO4)2 gel from which it could be eluted with Na citrate solutions. Various possibilities are entertained: that the thrombocytopenic effect of normal plasma is due to a sub-clinical transfusion reaction, to platelet incompatibility or to effect of products of platelet disintegration.