In-stent stenosis: potential role of increased oxidative stress and glutathione-linked detoxification mechanisms.

This study was designed to determine whether red-cell oxidative stress status and antioxidant enzyme levels can serve as markers in patients predisposed to in-stent stenosis. Blood was collected from patient groups undergoing coronary angiography for chest pain evaluation, namely, group A (without coronary artery disease), group B (previous coronary stents without in-stent stenosis), and group C (previous coronary stents with in-stent stenosis). Thiobarbituric acid reactive substances (measure of lipid peroxidation), glutathione-linked detoxification enzymes, catalase, and superoxide dismutase were determined. Compared with group A, patients in group C showed increased lipid peroxidation products and glutathione-S-transferase but decreased glutathione peroxidase and glutathione reductase activities. Results in group B patients were intermediate between those of groups A and C with significant decreases in glutathione peroxidase versus controls. In-stent stenosis is associated with significant increase in lipid peroxidation and attenuated glutathione-linked detoxification enzymes, consistent with oxidative stress.