Increased nitrotyrosine production in patients undergoing abdominal aortic aneurysm repair

Vascular inflammation is implicated in the pathogenesis of atherosclerosis and abdominal aortic aneurysm (AAA), and is thought to involve reactive species such as the nitric oxide-derived oxidant peroxynitrite. In the present study nitrotyrosine was measured as a stable marker of peroxynitrite production in vivo.

Perioperative blood samples were obtained from patients undergoing elective open or endovascular repair of an AAA and from patients with intermittent claudication, smoking aged-matched controls, non-smoking aged-matched controls and non-smoking young healthy controls. Plasma nitrotyrosine was measured by an enzyme-linked immunosorbent assay.

The median plasma nitrotyrosine concentration in patients with an AAA (0.46 nmol nitrated bovine serum albumin equivalents per mg protein) was significantly higher than that in patients with intermittent claudication (0.35 nmol; P = 0.002), smoking controls (0.36 nmol; P = 0.001), non-smoking controls (0.35 nmol; P = 0.002) and young healthy controls (0.27 nmol; P < 0.001). Nitrotyrosine concentrations increased during early reperfusion in open AAA repair, but not during endovascular repair. AAA exclusion from the circulation reduced levels to control values (P = 0.001).

Patients with an AAA had raised levels of circulating nitrated proteins compared with patients with claudication and controls, suggesting a greater degree of ongoing inflammation that was not related to smoking.