Free Thiol Beta 2-Gpi (Beta-2-Glycoprotein-I) Provides A Link Between Inflammation And Oxidative Stress In Atherosclerotic Coronary Artery Disease

Objective:Atherosclerotic coronary artery disease is well recognised as an inflammatory disorder that is also influenced by oxidative stress. beta 2-GPI (beta-2-glycoprotein-I) is a circulating plasma protein that undergoes post-translational modification and exists in free thiol as well as oxidized forms. The aim of this study was to assess the association between these 2 post-translational redox forms of beta 2-GPI and atherosclerotic coronary artery disease.Approach and Results:Stable patients presenting for elective coronary angiography or CT coronary angiography were prospectively recruited. A separate group of patients after reperfused ST-segment-elevation myocardial infarction formed an acute coronary syndrome subgroup. All patients had collection of fasting serum and plasma for quantification of total and free thiol beta 2-GPI. Coronary artery disease extent was quantified by the Syntax and Gensini scores. A total of 552 patients with stable disease and 44 with acute coronary syndrome were recruited. While total beta 2-GPI was not associated with stable coronary artery disease, a higher free thiol beta 2-GPI was associated with its presence and extent. This finding remained significant after correcting for confounding variables, and free thiol beta 2-GPI was a better predictor of stable coronary artery disease than hs-CRP (high-sensitivity C-reactive protein). Paradoxically, there were lower levels of free thiol beta 2-GPI after ST-segment-elevation myocardial infarction.Conclusions:Free thiol beta 2-GPI is a predictor of coronary artery disease presence and extent in stable patients. Free thiol beta 2-GPI was a better predictor than high-sensitivity C-reactive protein.