Interleukin 18 in acute myocardial infarction.

Interleukin 18 in acute myocardial infarction Interleukin 18 (IL-18), which is a recently cloned cytokine synthesised by KupVer cells, has been shown to activate macrophages. 1 Macrophages and T cells have been reported to be activated in patients with acute myocar-dial 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 myo-cardial 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 myo-cardial damage in patients with acute MI. We evaluated 24 patients with acute MI (19 men and five women aged 39–79 years). Patients diagnosed with acute MI had to have been admitted within six hours of the onset of symptoms. The diagnosis of acute MI was based on the presence of typical chest pain which persisted for at least 30 minutes, ST segment elevations > 0.2 mV in at least two contiguous leads, and an increase in serum creatine kinase activity to twice the upper limit of normal (> 250 IU/l). The diagnosis of congestive heart failure was based on a history of dyspnoea and symptomatic exercise intolerance with signs of pulmonary congestion or peripheral oedema at clinical examination , and following usual investigations. As a control group, we included 12 age and sex matched patients who had no evidence of coronary stenosis or coronary spasm on coronary angiography. No patient had evidence of septicaemia, collagen vascular disease, advanced liver disease, renal failure, malig-nancy or infectious disease. Blood was sampled immediately after admission and at 1, 2, 3, 6, and 9 hours after admission and then every 12 hours until five days after admission. Blood was drawn from the antecubital vein into silicone tubes (4.5 ml of blood and 0.5 ml of 0.13 M/l sodium citrate), and centrifuged for 15 minutes at 1600 g at 40°C. The plasma was stored at −80°C until assayed. Human IL-18 was measured by an enzyme linked immuno-sorbent assay (ELISA) developed by Hayash-ibara Inc, Okayama, Japan. 3 Serum creatine kinase-MB (CK-MB), myoglobin, lactate de-hydrogenase (LDH) activities, and leucocyte counts were measured by an autoanalyser. …