Discrepancies between immunological and caseinolytic plasma plasminogen assays in health and hyperfibrinolytic states

A sensitive immunological assay for plasminogen and/or plasmin was developed by using a haemagglutination inhibition technique. Plasma and the corresponding euglobulin fraction of healthy subjects and of patients with hyperfibrinolysis (liver cirrhosis, thrombolytic treatment) were assayed for plasminogen using immunological and caseinolytic techniques. In hyperfibrinolytic states discrepancies were found between immunoreactive and caseinolytic plasma plasminogen whereas a good correlation was observed between immunoreactive and caseinolytic euglobulin plasminogen. Experiments in vitro suggested that these discrepancies might depend on the presence in hyperfibrinolytic plasma of variable amounts of plasmin(ogen)-related antigen which has no caseinolytic activity and is not precipitated with euglobulin.