--Source: American Academy of Neurology, April 6, 2006

Children with neurological autoimmune diseases develop immune reactions to other targets in their bodies and in food early in their disease, according to research conducted at the Department of Pediatric Neurology at the Hospital for Sick Children, in Ontario, Canada.

The research team, headed by Brenda Barnwell, M.D., studied 166 children: 63 with an autoimmune demyelinating syndrome (either multiple sclerosis or an isolated event of central nervous system autoimmunity), 43 with type 1 diabetes (also an autoimmune disease), 31 with a non-autoimmune neurological condition, and 30 healthy controls. They examined blood samples for T cell proliferation in response to exposure to a variety of antigens (targets), including myelin protein from nerve cells, proteins in the pancreas, and proteins in milk. T cells are the body regulators of the immune response. Increased T cell proliferation is a characteristic of autoimmune disease, in which the immune system attacks body tissues.

As expected, more children with central nervous system autoimmunity had T cell proliferation after exposure to myelin than control children (50 percent versus 10 percent). About a quarter of these children also showed a response to proinsulin, a T cell target in type 1 diabetes. Over 60 percent also responded to a protein in milk. Of the children with type 1 diabetes, 90 percent responded to pancreatic antigens as expected. Almost as many (79 percent) responded to myelin, and 90 percent responded to milk protein.

"Even at the onset of their disease, children with autoimmune diseases harbor T cells that will react against proteins within their tissues," Dr. Barnwell said. "The responses seen against milk proteins raise the possibility that substances in food may be associated with autoimmunity."