[Staphylokinase and its mutants: a new generation of thrombolytic agents].

Staphylokinase which is extracted from Staphylococci has been known for more than 40 years as a profibrinolytic compound. It has been obtained more recently by genetic engineering. Staphylokinase activates plasminogen into plasmin. It is a promising new thrombolytic agent for the treatment of acute myocardial infarction and thromboembolic disease in general. It is a fibrin specific thrombolytic agent which does not decrease plasma fibrinogen level in treated patients. However it is antigenic and the group of Louvain has made much effort to reduce its antigenicity without decreasing its thrombolytic activity. Mutants with a reduced antigenic activity have been recently obtained. These new thrombolytic agents could be superior to currently used drugs. Staphylokinase mutants could have a better benefit/cost ratio than other thrombolytic agents.