Anti-streptokinase antibodies and streptokinase resistance in an Aboriginal population in northern Australia

Background: Thrombolytic treatment with streptokinase in acute myocardial infarction has proven to be safe and effective in Caucasian populations with relatively low levels of anti-streptokinase IgG and streptokinase resistance. Higher levels of antibodies, as seen in previous recipients of streptokinase therapy, cause more adverse reactions and may result in lower efficacy. Aims: To examine the levels of anti-streptokinase IgG. and streptokinase resistance in a population subjected to endemic streptococcal infections. Methods and Results: Thirty Aboriginal adults from a remote community in Northern Australia with endemic streptococcal infections and 15 non-Aboriginal adults from an urban community without endemic infections participated in this study. Aboriginal adults exhibited levels of anti-streptokinase IgG and streptokinase resistance that, respectively, were almost 20 and 15 times greater than the values of non-Aboriginal adults. At least 23% of Aboriginal adults had sufficiently high levels of streptokinase resistance to neutralise a standard 1.5 million unit dose of streptokinase. Conclusions: Aboriginal adults from a remote community had dramatically elevated levels of anti-streptokinase IgG and in vitro, streptokinase resistance. Prospective studies are needed to assess the clinical relevance of streptokinase resistance in populations from areas with endemic streptococcal infection.