Archive | MIND RSS feed for this section

Comment on: Maternal autoantibodies are associated with abnormal brain enlargement in a subgroup of children with autism spectrum disorder

14 Feb Antibodies figure

In 2008 a paper opened up a new area of research in autism risk factors: Autism: maternally derived antibodies specific for fetal brain proteins. The researchers at the U.C. Davis MIND Institute found that for a subset of autistic kids, they could find antibodies in the mothers’ sera that reacted to human fetal brain tissue. Other teams have found similar results, and the MIND researchers have continued to explore this topic.

In the present study, the researchers studied 131 ASD kids and 50 non-ASD controls. 10 of the ASD kids were born to mothers with the brain specific autoantibodies detected in their serum. Autism severity, by their measure, was the same for the two ASD groups. The rate of develpmental regression is the same for the two groups, but strikes me as rather high at 40-50% . Previous studies by this team and others indicated a higher rate of regression in the ASD kids in the maternal-autoantibody group.

Brain volumes were measured via MRI. Most children were tested during sleep. 10 children (all ASD) were tested under anesthesia. Scans were corrected for instrument distortions before volumes were measured. Brain volumes were higher for the ASD kids than the typical kids, consistent with previous results. However, the kids in the maternal autoantibody group had brain volumes even higher than the rest of the ASD kids. The kids in the maternal autoantibody group had brains 12% larger on average than the non ASD kids, while the rest of the ASD group had about 4.4% larger volumes.

The volume differences were not the same over the entire brain:

Furthermore, the frontal lobe was selectively enlarged in the ASD-IgG children relative to other ASD children, and both gray and white matter were similarly affected.

Previous work by the authors indicate the possibility that the autoantibodies themselves might cause brain differences resulting in autism. Their animal model was rhesus monkeys, whose mothers were injected with the autoantibodies.

The authors note there are a number of open questions:

Obviously, several questions remain: What are the brain antigens recognized by the 37/73 kDa maternal IgG autoantibodies, and what is their role normal neurodevelopment? What induces the production of these antibodies in some women but not in others? What is the mechanism by which these maternal autoantibodies alter brain development? Are there processes that could be implemented to block the deleterious effects of the antibodies? Studies are currently underway to address each of these issues and they will undoubtedly shed more light on the role that maternal
autoantibodies may play in ASD and abnormal brain enlargement in ASD.

Another open question they raise has to do with siblings of the autoantibody ASD kids. In specific, since these autoantibodies can persist in the mother’s serum for many years, it is likely that younger siblings are exposed to them as well. If these children do not develop ASD, what is the reason?

The brain volume differences are shown in summarized in this figure:

Antibodies figure

There is a large spread for the brain volumes for the non-autoantibody ASD kids. While on average they are larger, a number are comparable to the average for non-ASD kids. Also, there is a large overlap between the ASD groups from parents positive for the autoantibodies and without the autoantibodies. The kids in the autoantibody group are almost all at the high end of the distribution for the non-ASD kids.

The main thing this paper adds to the autoantibody story is evidence that this may represent a separate group within the ASD population. The work is being performed on members of the Autism Phenome Project. If this is a separate group, so far the evidence is only in brain volume. The authors note: “There were no differences in age, height, autism severity, or DQ between the two ASD groups. Furthermore, the two groups did not differ in the rate of parent reported history of regression.” So on other physical measures, and on autism-based measures, there are no differences. Obviously it would be valuable to see diffrences in autism-specific measures so we could back track how those measures are related to etiology and brain structure. But it is also interesting that this group does not have differences as it could indicate multiple pathways are not always distinct in the end result in autism development.

Nordahl, C., Braunschweig, D., Iosif, A., Lee, A., Rogers, S., Ashwood, P., Amaral, D., & Van de Water, J. (2013). Maternal autoantibodies are associated with abnormal brain enlargement in a subgroup of children with autism spectrum disorder Brain, Behavior, and Immunity DOI: 10.1016/j.bbi.2013.01.084

ResearchBlogging.org


By Matt Carey

Autism Phenome Project announces first results at the Asia Pacific Autism Conference

8 Sep

The Asia Pacific Autism Conference is ongoing in Perth Australia. Prof. David Amaral of the Mind Institute at U.C. Davis (California) will speak and present the first results from the Autism Phenome Project. This is a study to separate autism into various groups, or phenomes.

Here is a blurb from the press announcement for the conference:

The announcement of the first results of the Autism Phenome Project, the largest and most comprehensive assessment of children with Autism ever attempted. The project started in 2006 and is being conducted at the MIND Institute at the University of California, Davis (UC Davis). It is headed by Dr David Amaral and involves 52 scientists across eight fields. Dr Amaral is the President of the International Society of Autism Research. He is Distinguished Professor of Psychiatry and Behavioural Sciences at the Centre for Neuroscience at UC Davis. He is also Research Director and Beneto Foundation Chair of the MIND Institute. Dr Amaral will announce the results.

An Australian news outlet carried the story as US researchers’ discovery promises answers on autism.

Researchers from the University of California Davis’s MIND Institute in Sacramento began the Autism Phenome Project in 2006. They have been studying the brain growth, environmental exposure and genetic make-up of 350 children aged between 2 and 3 1/2 years, and have so far found two biologically distinct subtypes of autistic brain development.

One group of children – all boys – had enlarged brains and most had regressed into autism after 18 months of age; another group appeared to have immune systems that were not functioning properly.

Prof. Amaral’s slides have been made available.

They show, amongst other findings

Total cerebral volume is highly variable in ASD, but appears to be on average higher in ASD boys than controls.

There are various onset types: early onset, plateau, and regression.

Those who exhibit loss of skills have enlarged brains. But, interestingly, the head circumferences start to diverge at about 4-6 months. I.e. there are signs even before the regression occurs.

However, he has a talk “Neurobiological and neuro-immune features of Autism” with the following abstract:

The slides do not appear to discuss the immune phenotype mentioned in the press. However, Autism now affects 1:110 children in the United States. It is a complex disorder that likely has many variants and various etiologies. The first half of this presentation evaluates the hypothesis that the amygdala plays an important role in the pathophysiology of autism. First, MRI studies of the amygdala in children with autism are presented. Then, postmortem data on the morphology of the amygdala in autism are described. Observations are presented both on neurons and glia in the amygdala. Taken together these data confirm that the amygdala is clearly pathological in autism. Given that the amygdala is pathological, what might this pathology contribute to the behavioural impairments of autism? To address this issue, research on the nonhuman primate is discussed. These studies highlight a role for the amygdala in fear regulation and perhaps in mediating the co?morbid anxiety in autism. In the second part of the talk, data demonstrating abnormalities of the immune system of children with autism and a subset of mothers of children with autism are discussed. I also review findings of a nonhuman primate model of autism based on a neuroimmune intervention.

Autism Baby Siblings Study: recurrence risk 19%

15 Aug

Results of the MIND Institute’s baby sibling study have been published in the journal Pediatrics. The study puts the recurrence risk of autism at 19%. In other words, a family with one autistic child has, on average, a 19% chance that a subsequent child will be autistic. The study authors stress that the risk may be higher in some families and lower in others.

More discussion can be found in various news outlets carrying the story, including

http://m.heraldextra.com/news/science/health-med-fit/article_a90c6549-3444-5b6a-800a-85aba7234914.html

Onset patterns in autism: correspondence between home video and parent report

27 Jul

Regression is a major topic in autism. Children who lose abilities at a very young age. In Onset patterns in autism: correspondence between home video and parent report, Sally Ozonoff, Ph.D. and a team of researchers at the U.C. Davis MIND Institute looked at the developmental trajectories of children, autistic and non autistic. They reviewed home videos of the children to map those trajectories. They monitored social communication as a function of time.

What they found was even more complex than expected. Instead of finding that some children show low levels of social communication from very early in life. A second group has early high levels of social communication, followed by significant decreases over time (regression). But, there was a third group: a group which was more typical in development followed by not regression, but a plateau in progress in social communication.

The numbers of children in the study are small (53 autistic children), making it unlikely to get a precise idea of what fraction of the children follow each trajectory. According to the IMFAR abstract for this study:

Bayesian Information Criteria were used to select the number of trajectories that best fit the data. There was strong support from coded home video for 3 onset trajectories. The first “early onset” trajectory (n = 20) displayed low rates of social-communication behavior at all ages. The second “regression” trajectory (n = 20) displayed high levels of social-communication behavior early in life and significantly declined over time. The third “plateau” trajectory (n = 12) was similar to the typical children early in life but did not progress as expected. There was no support for a mixed (early signs + regression) trajectory.

Here is the abstract for the published paper:

OBJECTIVE:
The onset of autism is usually conceptualized as occurring in one of two patterns, early onset or regressive. This study examined the number and shape of trajectories of symptom onset evident in coded home movies of children with autism and examined their correspondence with parent report of onset.

METHOD:
Four social-communicative behaviors were coded from the home video of children with autism (n = 52) or typical development (n = 23). All home videos from 6 through 24 months of age were coded (3199 segments). Latent class modeling was used to characterize trajectories and determine the optimal number needed to describe the coded home video. These trajectories were then compared with parent reports of onset patterns, as defined by the Autism Diagnostic Interview-Revised.

RESULTS:
A three-trajectory model best fit the data from the participants with autism. One trajectory displayed low levels of social-communication across time. A second trajectory displayed high levels of social-communication early in life, followed by a significant decrease over time. A third trajectory displayed initial levels of behavior that were similar to the typically developing group but little progress in social-communication with age. There was poor correspondence between home video-based trajectories and parent report of onset.

CONCLUSIONS:
More than two onset categories may be needed to describe the ways in which symptoms emerge in children with autism. There is low agreement between parent report and home video, suggesting that methods for improving parent report of early development must be developed.

The last statement in the results is obviously intriguing. “There was poor correspondence between home video-based trajectories and parent report of onset.”

Here is the segment of the IMFAR abstract:

There was poor correspondence between parent report and home video classifications (kappa = .11, p = .30). Only 9 of 20 participants whose home video displayed clear evidence of a major decline in social-communication behavior were reported to have had a regression by parents. Only 8 of 20 participants with evidence of early delays in social-communication on video were reported to demonstrate an early onset pattern by parents. Of the 10 whose parents described a plateau, only 3 had home video consistent with this pattern.

So, none of the three groups were able to correctly recall the trajectory. Not the parents of kids who regressed. Not the parents of kids who plateaued. Not the parents of kids who had early onset autism.

As parents we’d like to see ourselves as the experts of our children. And, frankly, we are. No one else knows them like we do. But that doesn’t make us infallible.

The study was presented at IMFAR and Shannon Rosa wrote about it for The Thinking Person’s Guide to Autism.

So what do parents really think causes autism?

12 May

According to the MIND institute, presenting at IMFAR:

The two most common causes of autism cited among all parents was an environmental cause (51%) and/or a genetic cause (51%). Vaccines (22%) were the third most commonly believed etiological factor, followed by 20% of parents who did not know or have a guess as to what may cause autism.

This is an interesting set of results to me. I’m frequently told that the overwhelming majority of parents believe vaccines cause autism. Turns out less than a quarter do.

Also of interest was the following statement:

Vaccines are commonly cited as a cause by parents in all ethnic groups despite a clear lack of scientific evidence demonstrating a relationship between autism and either the measles, mumps, rubella (MMR) vaccine, or thimerosal containing vaccines

Wasn’t that long ago that autism anti-vaxxer supermo Rick Rollens was basically in charge of MIND. How times have changed.

Detection of Plasma Autoantibodies to Brain Tissue in Young Children with and without Autism Spectrum Disorders

25 Mar

Researchers at the MIND Institute published studies in the past few years correlating antibodies to brain tissue and autism. The first study of this sort (that I recall) studied whether the mother had antibodies to fetal brain tissue: Autism: maternally derived antibodies specific for fetal brain proteins. Other studies have looked at autoantibodies within the plasma of the autistics themselves: Detection of autoantibodies to neural cells of the cerebellum in the plasma of subjects with autism spectrum disorders.

The idea is fairly simple. If the mother or the autistic has antibodies against brain tissue, this might lead to an increased risk of autism.

There are even patent applications in for use of these methods to For example, a 2011 patent application US20110038872A1: METHODS OF DIAGNOSING AND TREATING AUTISM:

Determining a risk of an offspring for developing an autism spectrum disorder comprises identifying in a biological sample from the mother of the offspring in the presence of maternal antibodies that bind to the biomarkers

This past week, another paper from the MIND group came out:

Detection of Plasma Autoantibodies to Brain Tissue in Young Children with and without Autism Spectrum Disorders

In this study they looked for autoantibodies and compared autistics and non-autistics. They found no differences between the groups in frequency of autoantibodies.

Abstract
Autism spectrum disorders (ASDs) are characterized by impaired language and social skills, often with restricted interests and stereotyped behaviors. A previous investigation of blood plasma from children with ASDs (mean age = 5½ years) demonstrated that 21% of samples contained autoantibodies that reacted intensely with GABAergic Golgi neurons of the cerebellum while no samples from non-sibling, typically developing children showed similar staining (Wills et al., 2009). In order to characterize the clinical features of children positive for these autoantibodies, we analyzed plasma samples from children enrolled in the Autism Phenome Project, a multidisciplinary project aimed at identifying subtypes of ASD. Plasma from male and female children (mean age = 3.2 years) was analyzed immunohistochemically for the presence of autoantibodies using histological sections of macaque monkey brain. Immunoreactivity to cerebellar Golgi neurons and other presumed interneurons was observed for some samples but there was no difference in the rate of occurrence of these autoantibodies between children with ASD and their typically developing peers. Staining of neurons, punctate profiles in the molecular layer of the dentate gyrus, and neuronal nuclei were also observed. Taken together, 42% of controls and subjects with ASD demonstrated immunoreactivity to some neural element. Interestingly, children whose plasma reacted to brain tissue had scores on the Child Behavior Checklist (CBCL) that indicated increased behavioral and emotional problems. Children whose plasma was immunoreactive with neuronal cell bodies scored higher on multiple CBCL scales. These studies indicate that additional research into the genesis and prevalence of brain-directed autoantibodies is warranted.

” Immunoreactivity to cerebellar Golgi neurons and other presumed interneurons was observed for some samples but there was no difference in the rate of occurrence of these autoantibodies between children with ASD and their typically developing peers.”

Autism Clusters Found: areas with high incidence of autistic children

1 Jan

Researchers at the U.C. Davis MIND Institute has discovered regions in the state of California that have notably higher autism incidence. But the story is more complicated, and more sad, than one might think at first. Instead of indications of an “autism epidemic”, these clusters point to the fact that minority and poor children are much less likely to receive autism diagnoses.

I don’t have the paper yet (I’m still trying to find the abstract), but articles in the Woodland Daily Democrat and the San Diego Union-Tribune are reporting the story.

The clusters do not appear to point to environmental causes. Instead…well, read for yourself:

Researchers said that in this investigation the clusters probably are not correlated with specific environmental pollutants or other “exposures.” Rather, they correlate to areas where residents are more educated.

Children with autism diagnoses in these clusters are more likely to be White and have parents with high education levels. Again, a quote:

“In the U.S., the children of older, white and highly educated parents are more likely to receive a diagnosis of autism or autism spectrum disorder. For this reason, the clusters we found are probably not a result of a common environmental exposure. Instead, the differences in education, age and ethnicity of parents comparing births in the cluster versus those outside the cluster were striking enough to explain the clusters of autism cases,” said senior author Irva Hertz-Picciotto.

Kids in the “clusters” are about twice a likely to be diagnosed autistic and kids in nearby areas.

Twice as high.

To the many of us armchair epidemiologists who who have looked closely at the California Department of Developmental Services (CDDS) data, this comes as no surprise.

For me, the most memorable discussion of the autism clusters came from Autism Diva, in her post from July 1997, Malibu and Compton: Compare and Contrast.

Here is a graph from that post:

The South Central Regional Center, in a predominantly non-White, poor area of the Los Angeles basin, had an administrative prevalence of 33 per 10,000. Compare that to Westside Regional Center with a prevelance of 84. Westside is a much more affluent are with a higher proportion of White families.

From the San Diego Union-Tribune:

“There is mounting evidence that at least some of this clustering results from the greater access and utilization of services by those with more years of schooling,” the UC Davis researchers wrote.

Yes, there is a certain “I told you so” moment here. This blog, Autism Diva, Autism Natural Variation, Autism Street and others have been pointing out the apparent autism clusters in the raw CDDS data for years. Long before I started blogging. But the real story isn’t the effect such clusters have on the idea of the “autism epidemic”. Rather, this is a clear indication that we are underserving the disabled in our minority and poor communities. This is just plain wrong.

It is long past time for real autism advocacy organizations to work on increasing awareness and access to services in underserved areas. The autism “clusters” are probably not real. From where I sit, what is real are the “anti–clusters” of undiagnosed autistics, minorities, the poor, and, yes, adults.

Follow

Get every new post delivered to your Inbox.

Join 1,131 other followers