Plasma total neopterin and neopterin levels are significantly elevated in stroke patients before carotid endarterectomy surgery

Abstract Atherosclerosis is an inflammatory disease where activated immune cells are recruited into the artery wall forming artery plaques. Interferon-γ released by T-cells causes macrophage synthesis and release of 7,8-dihydroneopterin, an antioxidant and CD36 down-regulator. 7,8-Dihydroneopterin scavenging of superoxide and hypochlorite generates neopterin, whose measurement has been used as a marker for inflammation in cardiovascular disease. With low oxidative stress levels, 7,8-dihydroneopterin is likely to be the predominant product leading to an underestimate of macrophage activation when measuring neopterin alone. Here we measure both total-neopterin (7,8-dihydroneopterin plus neopterin) and neopterin along with IL-1β, in cardiovascular disease patients presenting with stroke. Plasma neopterin and total neopterin were measured by HPLC in 61 stroke patients undergoing carotid endarterectomy surgery and 61 age-matched controls. Plasma IL-1β was measured by ELISA. Neopterin, total-neopterin, and 7,8-dihydroneopterin were all significantly higher in carotid surgery patients than age-matched controls. Total-neopterin showed the greatest difference between patients and controls ( p ≤ 0.001). There was no significant difference in IL-1β levels between the stroke patients and healthy controls. The study shows that macrophage inflammation is elevated in cardiovascular disease patients presenting with stroke and the measurement of total neopterin is a more effective indicator of macrophage activation than neopterin alone.