Anti-streptokinase levels in Indian patients

Antistreptokinase antibodies and the response to thrombolysis with streptokinase in patients with acute ST elevation myocardial infarction

BACKGROUND AND OBJECTIVE

A large number of patients with ST elevation myocardial infarction (STEMI) continue to receive streptokinase (SK) in the developing countries. High levels of antistreptokinase (ASK) antibodies can result in failure of thrombolysis. This study was conducted to assess the presence of ASK antibodies in the general population and its effect on the outcome of thrombolysis with SK.

DESIGN

Prospective observational study.

SETTING

A tertiary care medical institute in Vellore, India.

PATIENTS

148 patients presenting with STEMI undergoing thrombolysis with SK were recruited.

MAIN OUTCOME MEASURES

The response to SK was assessed by reperfusion markers in the patients and they were categorised as good responders, probable responders and non-responders. Those who responded to SK and probable responders were considered to have benefited from thrombolysis.

RESULTS

60 patients (40%) had ASK antibody titres higher than the median. In patients with a window period <6 h, 73% of patients who benefited from thrombolysis had low ASK titres while 100% of the patients who did not benefit had high ASK titres (p=0.001). Similarly, in patients with a window period >6 h, 89% of patients who benefited from thrombolysis had low ASTK titres while 54% of those who did not benefit had high ASK titres (p=0.002).

CONCLUSIONS

ASK antibodies are present in significant titres in a large proportion of patients in developing countries, which leads to failure of thrombolysis in such patients. In endemic areas with high endemic streptococcal infection, alternative agents should be used for thrombolysis in STEMI.

Antistreptokinase antibodies: implications for thrombolysis in a region with endemic streptococcal infection

AIMS

To determine antistreptokinase antibody (anti-SK) titres in patients with the acute coronary syndrome from communities with endemic group A streptococcal infection because of the implications for streptokinase (SK) thrombolysis.

METHODS

Anti-SK titres were determined using a standard method in 47 consecutive SK naive patients, presenting to the Mt Isa Hospital emergency department, Australia, with an acute coronary syndrome. Both indigenous and non-indigenous subjects were enrolled. Antistreptolysin O (ASOT) and anti-DNAse B (ADB) titres were also determined.

RESULTS

Indigenous patients were more likely to have anti-SK antibodies (p < 0.001) than the non-indigenous cohort. Anti-SK antibody titres also correlated well with ASOT/ADB titres.

CONCLUSIONS

Anti-SK antibodies are highly prevalent in SK naive indigenous patients presenting with the acute coronary syndrome. Streptokinase should not be used for thrombolysis in populations with endemic group A streptococcal infection.

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.