Using 'Sick Cells,' Blood Tests May One Day ID Heart Attack, Stroke

Another unexpected event to the human body is the stroke, an acute impairment of cerebral circulation that lasts more than 24 hours, resulting in irreversible brain damage. Strokes are also a leading killer; some 750,000 Americans this year will have a stroke; 160,000 of them will die.

A clinician can determine your lifestyle, take some key physiological readings, and make an educated prediction that an individual might have a heart attack or stroke. But what if there was an actual laboratory test that could identify biological markers that could indicate the onset of either attack, and yet allow emergency medical intervention that would save a life or full mental capacity.

Such a test for a heart attack or stroke may be only a few short years away, according to a researcher participating in the development of this potentially invaluable diagnostic tool. Robert H. Christenson, PhD, Professor of Pathology, University of Maryland Medical School, Baltimore, MD, will present an assessment of where the tests development stands in a presentation, "Nourin: An Early Specific Marker of Cardiac Ischemia?" at the 55th Annual Meeting of the American Association of Clinical Chemistry (AACC) being held July 20-24, 2003, at the Pennsylvania Convention Center, Philadelphia, PA. More than 16,000 attendees are expected.

What Are Nourins?

Many dictionaries and medical reference books will not carry this term because it was formerly known as a "cardiac-derived neutrophil chemotactic factor," a factor that is released by heart tissues in response to reversible and irreversible ischemia (inadequate circulation of blood to the myocardium, usually as a result of coronary artery disease).

What makes this marker important is that ischemia does not kill cells right away. There is a cardiac-derived isoform specific for ischemia, and when the condition occurs, the marker or chemotactic factor is released, drawing neutrophils into the tissue for repair of injured tissue. Nourin-1 is the earliest biological signal that this form of heart failure is occurring. Accordingly, Dr. Christensen believes that if Nourins can be identified, medicines can be administered to the ischemic patient, saving cells and the patient's life.

He suggests that a blood test is the optimum test to identify Nourins, a 3,000 molecular-weight protein. Presently, studies are underway to develop a better antibody, which could indicate when the cells are sick. He adds that such a test is three to five years away from use in our nation's laboratories.

Stringing the Stroke Markers

Strokes are related to heart disease and therefore have the potential for early intervention due to marker identification. There is presently no diagnostic test to predict the onset of a stroke. But Dr. Christenson and others believe that a blood test could identify a panel of markers, stringing together a series of proteins that could lead to the development of strategies for preventing strokes.

Such an effort is already in trials with Biosite® Inc., San Diego, CA. The company has already developed the Triage BNP test, currently the only blood test now in use at hospitals for measuring b-type natriuretic peptides and their relation to cardiac disease.

Both tests will have a profound impact on efforts to treat heart disease and cerebral circulation disorders. This presentation before the managers of our nation's leading laboratories is an important first step in this diagnostic revolution.

The American Association for Clinical Chemistry (AACC) is the world's most prestigious professional association for clinical laboratorians, clinical and molecular pathologists, and others in related fields. AACC's members are specialists trained in the areas of laboratory testing, including genetic disorders, infectious diseases, tumor markers and DNA. Their primary professional commitment is utilizing tests to detect, treat and monitor disease.