Until recently, DVT was thought to be solely a blood or vascular disorder. Now, scientists from the University of Michigan Medical School have discovered intriguing new evidence to support the idea that the development of blood clots in veins just like blocked arteries in atherosclerosis is an inflammatory process.
"When a blood clot develops in superficial veins of the leg a condition called phlebitis the redness and swelling associated with inflammation are visible," says Thomas W. Wakefield, M.D., a scientist and vascular surgeon in the U-M's Cardiovascular Center. "When a clot forms deep inside the leg, these signs are hidden, so physicians have rarely associated DVTs with inflammation."
Working with Daniel D. Myers, DVM, MPH, an assistant professor of vascular surgery and animal medicine in the U-M Medical School, Wakefield is trying to figure out exactly what happens inside veins when a blood clot develops. In a study published in the November 2003 issue of The Journal of Vascular Surgery, he and Myers report that inflammatory molecules and immune system cells play a major role in the process.
The U-M scientists used four types of mice in the study. The first was a strain of genetically engineered mice developed by co-author Denisa D. Wagner, Ph.D, a professor of pathology at Harvard Medical School. A genetic mutation in these mice causes them to have abnormally high levels of a pro-inflammatory molecule called
P-selectin circulating in their blood plasma. In previous studi