Interleukin 18 (IL-18), which is a recently cloned cytokine synthesised by Kupffer cells, has been shown to activate macrophages.1 Macrophages and T cells have been reported to be activated in patients with acute myocardial infarction (MI).2 IL-18 is postulated to play a role in the development of myocardial dysfunction through activation of immune cells. However, the circulating concentration of IL-18 has not been reported in patients with acute MI.

To elucidate the changes in the release of IL-18 in patients with coronary artery disease, we examined the correlation between IL-18 concentrations and the serum activities of myocardial enzymes, estimating myocardial necrosis or atrial natriuretic peptide (ANP). Our goal was to determine whether measurement of IL-18 could be used as a new indicator of myocardial damage in patients with acute MI.

We evaluated 24 patients with acute MI (19 men and five women aged 39–79 years). …