Increased plasma levels of interleukin-8 in patients with unstable angina pectoris

Interleukin-8 is a proinflammatory cytokine with chemo-attractive and major activator properties on neutrophils. The very few studies in literature on the IL-8 behaviour in myocardial ischaemia refer only to acute myocardial infarction. This study investigates the IL-8 behaviour in stable angina pectoris after myocardial ischaemia induced by dipyridamole (14 patients) and in unstable angina pectoris, Braunwald's class III (35 patients). In stable exercise angina following dipyridamole-induced myocardial ischaemia, the plasma IL-8 levels did not increase. In unstable angina pectoris increased plasma IL-8 levels were evidenced in 25 of the 35 patients, after an average interval of 20 +/- 1.2 hours from the last spontaneous episode of angina pectoris. The IL-8 behaviour was different in class III B patients as compared to class III A: only 30% of the patients in class III A presented transient increase of IL-8, while 70% of the class III B presented increased IL-8 with a median value of 900 pg/ml within the first 24 hours from the last spontaneous episode of angina pectoris. The increased plasma IL-8 levels within the first 24 hours from the spontaneous episode could represent a marker of primary angina pectoris, Braunwald's class III B.