快猫短视频

THE hunt for clues to the causes of autism has taken another turn. The discovery of immune-system proteins in the guts of children with the condition adds new weight to the controversial idea which suggests that autism could be the result of the body turning on itself.

Researchers have already suggested that there could be a link between autism and the MMR vaccine (快猫短视频, 17 February 2001, p 17). In the latest work, Simon Murch and colleagues from the Royal Free Hospital and University College Medical School in London studied 25 children with regressive autism, in which symptoms begin between the ages of one and two. In 23 of the children, they found IgG antibodies and complement proteins bound to the same sites on the small intestine. None of the children they tested without autism had these two proteins close together in their gut. Murch says this pattern is usually a marker of an autoimmune process.

This isn鈥檛 the first time signs of autoimmunity have been found in autistic children. But Murch and his colleagues say their results are clearer and more specific than previously reported immune responses in the colon. If autoimmune disease sets in at an early age, says Murch, it can impair brain development and could lead to autism.

But other immunologists aren鈥檛 convinced. The molecules Murch found could be the result of inflammation, says Derek Jewell of the John Radcliffe Hospital in Oxford, who contributed to a recent Medical Research Council report on the origins of autism. 鈥淚t doesn鈥檛 mean to say that autism is an autoimmune disorder,鈥� he says.

Julio Licinio of the University of California in Los Angeles, who edits the journal Molecular Psychiatry and is an expert on the link between immune system activity and depression, says there are likely to be many types of autism, with different origins and triggers. But the immune system may be the common denominator, he says.

Murch鈥檚 team includes Andrew Wakefield, who last year sparked the controversy surrounding autism and the MMR vaccine. But the researchers say that speculation about the link between MMR and autism needs to be put to one side, and that their findings don鈥檛 rule vaccination in or out as a cause of autism. Known autoimmune diseases may be set off by many factors, including bacterial or viral infection, or diet.

If the proteins Murch and his team have found are the result of an autoimmune reaction, the next step is to find out what the immune system is attacking and to look for the trigger. Arguments over autism and MMR have overshadowed this important line of research, says Murch.