Plasmin‐a2‐antiplasmin complexes in bleeding disorders characterized by primary or secondary fibrinolysis

Summary. A two‐dimensional immunoelectrophoresis (2DIEP) method detects plasmin complexed to its major inhibitor, α2‐antiplasmin, in plasma in the blood of patients during (a) thrombolytic therapy with urokinase, (b) episodes of disseminated intravascular coagulation (DIC) with active fibrinolysis, and (c) episodes of fibrinolytic haemorrhage without evidence of DIC. Clearance of the complexes from the blood is rapid and their detection thus implies active plasmin generation at the time of blood sampling or within the preceding 24 h. Abolition of the complexes using tranexamic acid therapy allowed surgery without bleeding in two previously grossly haemorrhagic patients in group (c). Antithrombin III complexed with activated procoagulants was detected using a similar 2DIEP method in only two of fofour patients with DIC. Abnormalities of α2‐macroglobuin were detected on 2DIEP of plasma in the patients studied with proteolytic disorders; these did not appear to reflect complex formation.