Anti-streptokinase antibodies

The use of thrombolytics has significantly improved the management of patients with acute myocardial infarction but available molecules remains imperfect: restoration of normal coronary patency in about half the cases, risks of reocclusion, risk of bleeding. Streptokinase (SK), which is the least expensive agent, has disadvantages as do the other thrombolytics. SK, an immunogenic bacterial protein, has another feature: administration of SK leads to an immunitory response with the production of specific anti-streptokinase antibodies. These anti-streptokinase antibodies may interfere with the future administration of a compound containing SK either by inducing an allergic response or by neutralising the SK and making it ineffective. Moreover, anti-streptokinase antibodies, the result of previous streptococcal infections, are present in the circulation. Although the prevalence of anti-streptokinase antibodies in the general population, especially coronary patients at risk of myocardial infarction, is not well known and their potentially harmful effects are even less well known. In particular, the platelet aggregant effect in vitro of these antibodies in the presence of SK was not taken into account in the trials studying the influence of anti-streptokinase antibodies in the results of thrombolysis by SK. The anti-lytic effect of anti-streptokinase antibodies is well documented. For this reason, it is not recommended to readminister SK in patients who have previously been thrombolysed with a product containing SK.