Antibody response to Streptokinase

Abstract Background: Streptokinase is administered during acute myocardial infarction (AMI). It is prepared from beta haemolytic streptococci and in some cases pre-existing antibodies may compromise the use of streptokinase. Objective: To study levels of anti-streptokinase antibodies in AMI patients during thrombolytic therapy. Methods: Specific IgG, IgA, IgM and anti-streptokinase antibodies (ELISA) were studied in 246 cases. Pre and post-therapy levels of these antibodies were examined in 10 cases given streptokinase for AMI. Findings: Neutralizing anti-streptokinase were detectable in 61.7% of the controls which 0.43% of them had levels above the normal range. Neutralizing anti-streptokinase antibodies showed a positive correlation with the level of IgG anti-streptokinase antibodies (r=+0.55, P<0.001). By streptokinase administration, antibody levels dropped in day 1 however, they rose to pre-therapy values afterwards. One patient with elevated antibodies to streptokinase had an adverse immunological reaction to streptokinase (Serum sickness). Conclusion: Elevated pre-therapy levels of antibodies, the isotype IgG and possibly IgA, appear to be contradictory for further treatment with streptokinase.