A hemorrhagic diathesis has been observed in 2 patients who received 500 ml. of incompatible whole blood. In both, hypofibrinogenemia, hypoprothrombinemia and thrombocytopenia were observed and there was no evidence of increased fibrinolytic activity. In one, accelerin activity was reduced and there was transient evidence of a low-titered circulating anticoagulant.
The most likely explanation for the observed changes is intravascular coagulation in the recipient, presumably initiated by the thromboplastin-like activity of the hemolyzed red blood cells.