The Global Fool

our planet is our village

Maternal Antibodies, Brain Development and Autism
Sep08

Maternal Antibodies, Brain Development and Autism

By Roberta Attanasio The world of autism is a diverse one — autism and autism spectrum disorder are general terms for a group of complex and extremely heterogenous life-long neurodevelopmental conditions. Autism is also one of medicine’s greatest challenges. The current general consensus is that autism has multiple causes, and these causes can be as varied as the types of autism, which are not very well defined, yet. It is almost certain, though, that autism has its roots in very early brain development, development that can be influenced by a variety of factors. In a subset of childrem with autism, one of these factors may involve production of antibodies by the mother — not the antibodies that defend us from infection — rather, antibodies that bind our own molecules and therefore may lead to damage of our own cells. These antibodies are called auto-antibodies and, in the case of some autistic children, may induce damage of brain cells. During pregnancy, maternal antibodies are normally transferred to the fetus through the placenta to protect the infant from infection. However, the same placental transfer system can also allow auto-antibodies to reach the fetus — indeed, the placental transfer system does not discriminate between “good” and “bad” antibodies. If, before or during pregnancy, the mother produces auto-antibodies that bind the fetal brain, and these auto-antibodies reach the fetal brain, normal brain development can be hindered. Results from a recent study (July 2013) by Judy Van de Water (UC Davis MIND Institute) and collaborators show that mothers of children with autism produce auto-antibodies that bind seven proteins involved in different aspects of brain development. These proteins are found throughout the body and are present at significant levels in the human fetal brain, where they play established roles in neurodevelopment. The study, entitled “Autism-specific maternal autoantibodies recognize critical proteins in developing brain” and published in the scientific journal Translational Psychiatry, involved 246 mothers with children affected by autism and 149 mothers with normally developing children. Twenty-three percent of the mothers with children affected by autism produced auto-antibodies that recognized two or more of the seven proteins, whereas only 1 percent of the mothers with normally developing children produced such auto-antibodies. The investigators coined a special designation for the type of autism possibly linked to these auto-antibodies — maternal autoantibody-related (MAR) autism. Van de Water said “It is important to note that women have no control over whether or not they develop these autoantibodies, much like any other autoimmune disorder and, like other autoimmune disorders, we do not know what the initial trigger is that leads to their production.” The autoantibody/MAR hypothesis appears to be...

Read More
Autism and Air Pollution Go Together
Jun18

Autism and Air Pollution Go Together

By The Editors Autism, a severe developmental disorder that begins within the first three years after conception, is considered a global concern. The causes of autism are not well understood. Now, results from a study published online today, June 18, in the scientific journal “Environmental Health Perspectives” show that women exposed to air pollutants during pregnancy are up to twice as likely to have an autistic child than those living in areas with low air pollution. What is autism? The American Psychiatric Association defines autism as a disorder characterized by deficits in social interactions and communication skills, as well as the presence of stereotypic and repetitive behaviors. According to the Autism Research Institute “Most autistic children look like other kids, but do puzzling and disturbing things which are markedly different behaviors from those of typical children. In less severe cases on the spectrum (Pervasive Developmental Disorder (PDD) or Asperger’s Syndrome), children usually have speech and might even be intellectually gifted, but they have one or more “autistic” social and behavioral problems. The study has been carried out by researchers at the Harvard School of Public Health. The researchers examined data from Nurses’ Health Study II, a long-term study that began in 1989 (you can read more about the Nurses’ Health Study II here). Based at Brigham and Women’s Hospital, it involves 116,430 nurses from 14 U.S. states. The researchers studied 325 women who had a child with autism and 22,000 women who had a child without the disorder and examined the associations between autism and levels of pollutants at the time and place of birth. To estimate women’s exposure to pollutants while pregnant, the researchers used air pollution data from the U.S. Environmental Protection Agency (EPA), while adjusting for the influence of factors such as income, education, and smoking during pregnancy. The results show that exposures to diesel, lead, manganese, mercury and methylene chloride while pregnant were significantly associated with development of autism spectrum disorder. The correlation between mercury and diesel was particularly high. For most pollutants, associations were stronger for boys (279 cases) than girls (46 cases) and significantly different according to sex. Senior author Marc Weisskopf, associate professor of environmental and occupational epidemiology at the Harvard School of Public Health, said, “Our results suggest that new studies should begin the process of measuring metals and other pollutants in the blood of pregnant women or newborn children to provide stronger evidence that specific pollutants increase risk of autism. A better understanding of this can help to develop interventions to reduce pregnant women’s exposure to these pollutants.” However, it would be wise to consider alternative explanations for the apparent association of autism and air pollution found in this study. For example, all women involved...

Read More