High Ischemia-Modified Albumin Concentration Reflects Oxidative Stress But Not Myocardial Involvement in Systemic Sclerosis
Posted Dec 03 2009 11:14pm
By Didier Borderie and Colleague
Systemic sclerosis (SSc) is a connective tissue disease characterized by widespread vascular lesions and fibrosis of the skin and internal organs. In SSc, vasospasm causes frequent episodes of reperfusion injury and free-radical-mediated endothelial disruption. Primary myocardial involvement is far more common than initially suspected on clinical grounds and affects survival rates because it is associated with a poor prognosis. Myocardial fibrosis is thought to occur secondarily to repeated focal ischemia in the coronary microcirculation as a result of abnormal vasoreactivity, with or without associated structural vascular disease. The early and accurate identification of cardiac involvement is therefore of paramount clinical importance.
The concentration of ischemia-modified albumin (IMA), as measured by the albumin cobalt binding test (Ischemia Technologies, Inc.), is a new marker to rule out transient myocardial ischemia. This test measures the binding of exogenous cobalt to the NH2 terminus of human albumin. In the presence of myocardial ischemia, structural changes occur in the NH2 terminus of albumin, rapidly reducing its capacity to bind transition metal ions after an ischemic event.