Bryan Jepson, MD, says that families most susceptible to autism are those that have a history of allergies. It is these families that have common gene mutations which may contribute to autism, he says.
Dr. Jepson takes a chapter to explain the immune system in layman’s terms. I will boil it down in this way: when live foreign material, an antigen, enters the body, a T-helper cell (a white blood cell) decides what to do. This “Th” for T helper cell decides whether to invoke a Th1 response or a Th2 response.
- The Th1 response attacks using cells, effective against viruses and some bacteria.
- The Th2 response creates antibodies, more effective against pathogens outside the cells.
The immune system can become damaged, and the Th “general” starts making wrong decisions. If it calls for too many Th2 responses, allergies result. In addition, the individual is less able to fight off viruses. This can also cause widespread autoimmune reactions, where the body is attacking itself all the time.
Dr. Jepson cited a number of studies which have demonstrated that the quantity and function of immune cells are abnormal in children with autism. Researchers have also found plenty of evidence of food allergies in autism. Campbell et al found a common gene mutation to be a risk factor for autism; this MET gene is involved in brain, immune system, and gastro-intestinal tract.
So someone with a genetically weak immune system (family history of allergies) is exposed to a level of toxins that causes the immune system to become damaged. Then the body reacts toward most antigens with the Th2 response, whether that’s appropriate or not. As a result, the individual may get a lot of allergies, particularly food allergies. In addition, a virus (from a vaccine?) may not be dealt with by the immune system, and could be causing autism according to some theorists.
In fact, many studies have shown cases where viral infections including measles have induced autism, says Jepson. “It’s thought that these pathogens induce an immune response, resulting in neuroinflammation, autiimmune reaction, and brain injury,” says Jepson (p. 63).
An English team led by Andrew Wakefield published a study in 1998 examining 12 consecutive children referred to their clinic for chronic gastrointestinal symptoms and developmental disorders. Eight of the children were believed by their parents to have regressed because of the MMR vaccine. Wakefield found extreme bowel inflammation, especially in the small intestine, in all the children. He theorized that the measles virus in the MMR vaccine in some children creates an abonormal immune response that allows the measles virus to persist chronically. This gut inflammation allows toxins to enter the bloodstream from food or bacteria, ultimately causing secondary brain injury and autistic behaviors.
Jepson lays out the resulting storm of controversy following Wakefield’s publication, and concludes that there is not yet a conclusive answer to the question of how the MMR might be connected to autism.
Jepson, Bryan, MD, and Jane Johnson, Changing the Course of Autism, Sentient Publications, 2007, 354 pages