BOSTON CONFERENCE May 5, 2005(summarized by Veronique Bure)

BOSTON, Mass. (May 5, 2005) - Some 700 scientists from around the world who gathered in Boston this week shared exciting advances in understanding the causes of and treatments for autism disorders

Two studies presented to a conference on Autism help support other research that suggests subtle differences in the immune function of children with autism.

First study  Judy Van de Water of the University of California, Davis[1], and colleagues separated immune cells from 30 children with autism and 26 non-autistic children aged 2 to 5. They mixed in toxins and bacteria.  In response to bacteria, the researchers saw lower levels of immune signaling proteins called cytokines in the group with autism. These children also had irregular responses to a plant protein, but not to other toxins or to a measles, mumps and rubella vaccine. 

Cytokines are molecules that perform crosstalk between different cell types. They are important communicators.  Among other things, cytokines affect sleep and many children with autism have sleep disorders.

Second study:  Researchers analyzed immune cells from blood taken from 30 children with autism and 26 healthy children, all aged two to five years. Then the scientists exposed the cells to bacterial and viral agents, including vaccine antigens, which typically unleash T-cells, B-cells and macrophages, all part of the immune system.

The children with autism had 20 percent more immune system cells called B cells and 40 percent more natural killer cells.

Identification of both potential biological markers in the blood (biomarkers) and behaviors could possibly allow scientists and physicians to identify autism in infants, and thus initiate early treatment.

Role of the environment:

 The number of children diagnosed with autism has increased significantly in recent years, leading to think that non-genetic factors in the environment may be at least partially responsible. Studies that investigated this possibility included:

PCBs[2] and Language Development:  Dr. Tal Kenet, Michael Merzenich, and Isaac Pessah at the University of California, San Francisco and Davis, found that rats' exposure to polychlorinated biphenyls (PCBs) showed disturbances in the development of the brain's auditory cortex, but without affecting hearing. However, in humans such brain defects would almost certainly disturb language development in ways typical of autism, the researchers said. The study suggests that environmental factors may combine with genetic predispositions to contribute to the increased incidence of autism.