Abstract
.alpha.2-Antiplasmin is the principal plasma inhibitor of plasmin, with which it rapidly and irreversibly forms a complex. The simple technique of crossed immunoelectrophoresis against antiserum to .alpha.2-antiplasmin was applied to detect plasmin-.alpha.2-antiplasmin complex in plasma. The presence of this complex was demonstrated in patients in whom overactive fibrinolysis was the only or major contributor to severe hemorrhagic disorders arising spontaneously.