In a group of women with silicone breast implants, one in three had a measurable autoimmune response to the implants, according to a new study by UC Davis School of Medicine researchers Dr. Suzanne Teuber and Dr. M. Eric Gershwin. The women, many of whom had symptoms that developed after receiving their implants, had elevated levels of antibodies against collagen and of "antinuclear" antibodies. Both are indicators of an autoimmune reaction, in which the body's defense system turns against itself. The researchers believe the autoimmune response may be due to the foreign-body reaction that occurs when silicone bleeds out of the implant and into surrounding tissue. They released their findings at a recent meeting of the American Academy of Allergy and Immunology.