Patients with acute coronary syndromes express enhanced CD40 ligand/CD154 on platelets

Objective—To investigate whether CD40L/CD154 on platelets and soluble CD40L/CD154 may play a role in the inflammatory process of acute coronary syndromes. Design and setting—Observational study in a university hospital. Patients—15 patients with acute myocardial infarction, 25 patients with unstable angina, 15 patients with stable angina, and 12 controls. Main outcome measures—CD40L/CD154 on platelets, P-selectin/CD62P on platelets, solu-ble CD40L/CD154 serum concentrations. Results—Mean (SD) CD40L/CD154 expression on platelets was 6.2 (2.8) MFI (mean fluores-cence intensity) in the infarct group, 11 (3.3) MFI in the unstable angina group (p < 0.001 v inf-arction), 3.6 (0.9) MFI in the stable angina group (p < 0.01 v infarction; p < 0.001 v unstable angina), and 3.2 (1.0) MFI in the controls (p < 0.01 v infarction; p < 0.001 v unstable angina; NS v stable angina). Soluble CD40L/CD154 concentration was 5.2 (1.1) ng/ml in the infarct group, 4.2 (0.7) ng/ml in the unstable angina group (p < 0.001 v infarction), 2.9 (1.0) ng/ml in stable angina group (p < 0.001 v infarction and unstable angina), and 3.0 (0.5) ng/ml in the con