Preventive factor may be a cause of heart disease

According to a Yale study, a key immune factor produced by white blood cells that was thought to prevent hardening of the arteries may actually cause arteriosclerosis, one of the most common contributors to potentially lethal heart disease. An interdepartmental team of surgeons and scientists found that interferon-gamma, which is produced by white blood cells and was previously believed to inhibit the processes responsible for arteriosclerosis, increased blockages in animal models.

The researchers were looking to develop new animal models to assess human transplantation responses. Heart transplants frequently result in the greatly accelerated development of arteriosclerosis. The scientists inserted segments of arteries from pig or human hearts into the major blood vessel of mice that lacked immune systems and, as such, could not reject the foreign arteries. When the mice were treated with injections of pig or human interferon-gamma, the grafts developed arteriosclerotic lesions. “This observation,” said team member George Tellides, M.D., Ph.D., assistant professor of cardiothoracic surgery, “may improve our ability to develop treatments for arteriosclerosis. Also, we may be able to identify methods to genetically alter pigs to serve as organ donors of hearts resistant to arteriosclerosis.” The study was published in the January 13 issue of Nature.