Immune proteins attach to the surface of the implants

Bad news for Pamela Anderson and a lot of Hollywood starlets.

Austrian researchers have detected previously unknown proteins that accumulate on the surface of silicone breast implants, which could be the cause of immune reactions in women who possess them.

The FDA banned silicone-gel filled breast implants in 1992, after complaints that they caused autoimmune illnesses and even cancer. Thousands of women sued fabricant Dow Corning, forcing the company into bankruptcy. On Nov. 17, 2006, the FDA approved the request of two other companies to begin marketing the implants, as no evidence that breast implants cause either connective tissue autoimmune disease or cancer has been brought. "The extensive body of scientific evidence provides reasonable assurance of the benefits and risks of these devices", said FDA director for devices and radiological health Daniel Schultz.

But the Austrian researchers discovered that the proteins may be causing immune reactions in patients with breast implants and other types of silicone implants. "These proteins provide a link between silicone implants and autoimmune disease", says lead researcher Aleksandar Backovic, of Austria's Innsbruck Medical University.

Their research involved 23 healthy women who were undergoing breast augmentation for cosmetic reasons, including some who were removing or replacing implants due to complications. The scientists used a targeted proteomics approach to identify proteins adsorbed to the surface of silicone, because those proteins have been identified as key components in local immune reactions to silicone. "Thus far we have identified the 30 most abundant proteins deposited on the surface of silicone, the largest known inventory of such proteins so far."

The researchers state that the new report "shows that silicone promotes at least the adhesion of altered self-proteins, which in turn may trigger an autoimmune response of the immune system."

The study revealed the reaction is likely to occur many years - even decades - after implantation, rather than weeks or months later, that's why earlier studies failed to identify the protein adherence. The Austrian study team allows a closer scientific approach than was possible in the past. "For a long time, we considered silicone implants to be inert when they were placed in body".

"This research suggests that they are recognized as foreign, and that they may not only start, but fuel, an inflammatory response", says Renee Carter, from the National Research Center for Women and Families. But the study does not prove a link between silicone breast implants and autoimmune diseases like rheumatoid arthritis and lupus.

"The fact is that proteins attach to all kinds of biomedical devices implanted in the body. But it is a huge leap of faith to reach the conclusion that the presence of these proteins is responsible for triggering these autoimmune phenomena", said Bruce Cunningham, a professor of plastic surgery at the University of Minnesota. "Study after study has failed to show a link between silicone-filled breast implants and a greater incidence of disease in the women who have them," Cunningham says. "If FDA thought for a moment that there was a valid concern about connective tissue disease - or any disease - they would never have done that."

Others point to the fact that FDA ignored critical evidence suggesting an increase in autoimmune symptoms among women with implants. "There is plenty of reason to be concerned that at least some women are having bad reactions to silicone implants", said Diana Zuckerman, Ph.D., president of the National Research Center for Women and Families.