Anti-streptokinase titers and response to streptokinase treatment in Pakistani patients

In order to investigate whether anti-streptokinase (anti-SK) antibody titers have any effect on response to standard dose (1.5 million units) streptokinase (SK) therapy in patients with acute myocardial infarction, anti-SK titers in plasma were determined in 97 such patients. These patients were classified as 'responders' or 'non-responders' on the basis of a criteria which involved resolution of chest pain in less than 90 min after the start of thrombolysis, greater than 50% reduction of ST segment elevation in two contiguous leads showing maximum elevations in a 12-lead tracing, reperfusion arrythmias and slope of increase in creatine kinase over a 90-min period after initiation of thrombolysis. Anti-SK antibody levels in plasma were determined in these patients as well as in 50 normal healthy subjects by dissolution of clot method. Mean±S.D. anti-SK levels among responders, non-responders and normal healthy subjects were found to be 0.21±0.12, 0.25±0.22 and 0.21±0.15 million units, respectively. A comparison of these mean values by one-way ANOVA revealed no statistical difference (P=0.68). However, when compared with the reported values for a Western population, these values were found to be significantly higher (P<0.03). Whereas, compared to the reported values for an Indian population, these were significantly lower (P<0.0001). 42% of patients appeared to have responded to SK treatment, while 21% were found to be non-responders. There was no association between response to SK and anti-SK titers in these patients suggesting that the standard dose of SK (1.5 million units) may be quite appropriate for the Pakistani population requiring SK treatment for the first time.