NEUTRALIZING ANTIBODIES AFTER STREPTOKINASE TREATMENT FOR MYOCARDIAL-INFARCTION - A PERSISTING PUZZLE

Objective-To determine the development of titres of streptokinase (SK) neutralising antibodies after a single dose of SK, to establish when titres decrease to levels at which a second dose might be effective. D esign-Analyses of blood samples taken from patients at intervals after SK administration. Setting-Australian public hospital. Patients-104 p atients with acute myocardial infarction who were treated with SK and 27 controls who were not. Outcome measure-SK neutralising antibodies w ere measured once in each of the 27 controls and on 166 occasions in t he 104 treated patients. Results-Titres of SK neutralising antibodies rose after SK administration but returned to control levels by 2 years . Conclusions-SK might be effective again as a thrombolytic agent as e arly as 2 years after a single dose. These results are at variance wit h most previously published data and the reasons for this are not clea r. Data evaluating patency rates after standard doses of streptokinase in patients with increased titres of neutralising antibodies are nece ssary before SK neutralisation re-exposure to streptokinase can be usi ng the method recommended.