Effect of Streptokinase on Fibrinogen and Related Proteins in Plasma

We investigated the effect of streptokinase on determination of fibrinogen and related clottable proteins in an effort to assess the relative reliability of these determinations in monitoring patients being treated with streptokinase. Citrated plasma was incubated with and without streptokinase, then assayed for fibrinogen (I), fibnn(ogen) degradation products (II), total clottable protein (Ill), and plasminogen (IV). Values for I decreased rapidly. Values for Ill and IV generally paralleled those for I, values for Ill lacked adequate sensitiv-ity. II, low initially, increased to 80 mg/L in 1-2 h. Soybean trypsin inhibitor effectively stabilized all these constituents (except IV) in streptokinase-treated plasma, and we recom-mend that this (or some other such) inhibitor of fibnnolysis be used routinely when specimens are collected for these determinations. Data are presented that suggest that tran-sient polymers are formed, the clinical significance of which is not known. AddItional Keyphrases: monitoring therapy. clotting minogen fibrin degradation products disorders of hemosta