RESUMO
Inflammatory mediators are intimately associated with the cascade of events ading to atherosclerotic plaque initiation, development, and rupture. This recognition has stimulated the evaluation of several markers of inflammation as potential tools for cardiovascular risk prediction interleukin IL-18 originally was identified as an interferon [IFN-gamma] inducing factor in Kupffer cells and macrophages. Increased IL-18 expression has been reported in human atherosclerotic plaque, mediating IFN-gamma release locally. The aim of this study is to assess the relation between serum concentrations of interleukin IL-18 and the clinical instability of coronary artery disease and to evaluate the relation between IL-18 serum levels and the extent of myocardial dysfunction. This study included forty subjects. Twenty patients with acute coronary syndrome [ten with myocardial infarction and ten with unstable angina] and ten patients with stable angina. Ten apparently healthy subjects were used as a reference group. All patients were examined and underwent ECG, diagnostic coronary angiography, some routine laboratory investigations such as [Complete blood picture, erythrocyte sedimentation rate, fasting and post- prandial blood glucose, liver function tests and renal function tests] and specific laboratory investigation as Lipid profile assessment. Measurements of specific cardiac markers: [serum levels of CK, CK- MB, LDH and qualitative determination of troponin I]. Measurement of serum interleukin-18 [IL-18] and serum high sensitivity C- reactive protein [hs -[CRP]. Plasma concentrations of IL-18 were significantly increased in the unstable angina and MI groups in comparison with the stable angina and control groups [p < 0.01]. No difference in IL-18 oncentrations were found between patients with unstable angina, and patients with Q wave MI. Plasma IL-18 concentrations significantly correlated with decreased left ventricular ejection fraction [p = 0.001]. Plasma IL-18 concentrations are increased in patients with at acute- coronary syndrome and correlate with the severity of myocardial dysfunction