Neopterin and atherosclerotic plaque instability in coronary and carotid arteries

Inflammation plays a key role in atherosclerosis and plaque vulnerability,and monocyte/macrophage activation contributes to these processes. neopterin,a by-product of the guanosine triphosphate pathway,is produced by activated macrophages on stimulation with interferon-λ released from t lymphocytes,and is an activation marker for monocytes/macrophages. coronary angiographic studies have shown a relationship between increased circulating levels of neopterin and the presence of complex coronary lesions in patients with unstable angina pectoris (uap). furthermore,in an immunohistochemical study performed using coronary atherectomy specimens,a significandy higher prevalence of neopterin-positive macrophages was found in culprit lesions in patients with uap than in those with stable angina pectoris (sap). we recendy clarified that the presence of complex carotid plaques detected by carotid ultrasound was related to increased circulating levels of neopterin,and immunohistochemical localization of neopterin was observed in complex carotid lesions obtained from carotid endarterectomy in patients with sap. these findings suggest that neopterin is an important bio marker of plaque instability in both coronary and carotid atherosclerotic lesions.