Interleukin-18 and interleukin-18 binding protein levels before and after percutaneous coronary intervention in patients with and without recent myocardial infarction.

Serum levels of interleukin-18 (IL-18) and its endogenous antagonist IL-18 binding protein were measured in 84 patients before and after coronary angioplasty. Patients who had high levels of troponin I immediately before angioplasty were considered to have experienced a "recent" myocardial infarction. Concentrations of IL-18 (355 vs 316 pg/ml) and ratio of IL-18 to IL-18 binding protein (107 vs 69) were significantly higher among patients who had recent myocardial infarction than among those who did not, indicating a relation between unopposed IL-18 activity and recent myocardial infarction.