HEART DISEASE IN HUMAN

ATHENS, Ga. -- June 18, 1997 -- Scientists at the University of Georgia have discovered that an enzyme in a common bacterium is capable of activating blood-clotting in the human body. This is the first reported evidence of such an effect and may help explain the link between periodontal infections and heart disease. The new knowledge could lead to a vaccine that might neutralize the enzyme before it has a chance to activate blood-clotting and lead to cardiovascular diseases, a not uncommon occurrence in individuals with periodontitis.

"Periodontal disease is the number-one chronic infectious disease in the world," said Dr. James Travis, a professor of biochemistry and molecular biology who led the research team at UGA. "We believe it will be possible to make an inhibitor that will stop this enzyme in its tracks”. The study was published today in the the Journal of Biological Chemistry and was supported by the National Institutes of Health and by a grant from the Committee of Scientific Research in Poland.

The bacterium is known as Porphyromonas gingivalis, and it is a cause of adult periodontal disease, an infectious condition associated with a loss of connective tissue, resorption of bone and formation of infectious pockets. It is the most common cause of tooth loss in adults and is called an "opportunistic anaerobe" -- an organism living without oxygen and waiting to receive nutrition.

Though the full reason for periodontitis remains unclear, it clearly has a close relationship with P. gingivalis infections. Two similar forms of the enzymes produced by the bacterium are called gingipain Rs, and the team at UGA suspected they might be involved in causing blood clots. They also suspected an involvement with thrombin, a body chemical that cleaves a blood-plasma protein called fibrinogen into the insoluble protein referred to as a fibrin clot.

A number of studies have shown a link between mouth infections and heart disease. A report in the journal Science on April 11 revealed that in research involving 1,372 Pima Indians in Arizona, those with periodontal disease were 2.7 times as likely to suffer a heart attack as were those with healthy gums. This research, conducted by scientists at the State University of New York at Buffalo, was among the first to exclude smoking as a potential cause of gum disease, since few of the Indians in the study smoked