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The Microbiome In Regressive Autism

Posted Apr 01 2014 12:00am

Gut-brain By Teresa Conrick

The microbiome   keeps coming up daily in the world of science and health.  How is it involved in regressive autism?  What is regressive autism?

Children with an ASD who lose skills (e.g., social interaction and communication) have become known as a subgroup called regressive autism or late onset. Regressive autism usually refers to a child where parents report an early history of normal development for 12-24 months which is followed by a loss of previously acquired skills. Individuals with ASD often suffer from gastrointestinal (GI) disorders (e.g., diarrhea, constipation, bloating and gastro-esophageal reflux) [2,3]. Fecal Microbiota and Metabolome of Children with Autism and Pervasive Developmental Disorder Not Otherwise Specified

”By 1985 the incidence of regressive autism had equalled that from birth. By 1997 both types had increased although the regressive form was now >75% of the total occurrence. This suggests that an acquired condition was overtaking birth defects or purely genetic conditions……In the vast majority of cases, the emergence of autistic indications appears to happen in children who had developed normally[10,13,14], and before three years[15,16.]”  What is regressive autism and why does it occur? Is it the consequence of multi-systemic dysfunction affecting the elimination of heavy metals and the ability to regulate neural temperature?

“About one in three children with autism abruptly lose language, social or other developmental skills in their second year of life…..The results come from the synthesis of 85 studies published between 1980 and 2010 that examined regression, and include nearly 30,000 participants diagnosed with an autism spectrum disorder.”  SFARI: Regression may mark one-third of autism cases

 It seems that more and more research is finally making connections to the regression children experience as they begin symptoms of autism and the dysfunctional microbiome most of the children have:

We are just beginning to understand what comprises a “normal” gut microbiome, but there are already associations between unhealthy states and abnormal or imbalanced gut microbiota…..And in autism spectrum disorders (ASD), there are hints that the gut microbiome may play a role. Studies of fecal DNA extracts have found Clostridium or Desulfovibrio clusters over-represented in children with gastrointestinal complaints and ASD as compared to children with similar GI complaints but typical neuro-behavioral development32–34. Furthermore, clinical improvement has been reported anecdotally in children with ASD who develop fever35, receive oral antibiotics36, or ingest probiotics37, all of which are likely to alter the gut microflora. 

So we see normal babies who have GI issues and then begin to regress in skills.  They then receive a diagnosis of autism:

Regression is most often observed between the first and second birthday, with mean ages of regression reported across different samples between 16 and 20 months. 

GI microbes thus influence brain function and behavior through several sets of complex pathways. 

• “Immune Changes Linked to Regression, GI Distress & Repetitive Behaviors” : Some children with autism appear to develop normally in the first year or two of life. They then regress, losing developmental skills, particularly in sociability and communication. Studies have linked this autism pattern with greater frequency of medical problems such as GI distress……  Dr. Ashwood’s team found that children with more dendritic cells had more severe repetitive behaviors. They were also more likely to suffer chronic constipation. In the digestive tract, dendritic cells engulf many kinds of bacteria – both dangerous germs and normal digestive organisms. They carry these bacteria to lymph nodes to trigger various types of immune responses.

We know that the relationship between gut bacteria and host immune responses are very important .” Dr. Ashwood says. “If these immune cells react inappropriately to gut bacteria, this could lead to inflammation. Changes in dendritic cell function could impact and disrupt many immune processes including T cell activation and autoantibody production that have been shown to be dysfunctional in autism,” he adds.

•  Thimerosal is an organic mercury compound that is used as a preservative in vaccines and pharmaceutical products.... Thimerosal induces TH2 responses via influencing cytokine secretion by human dendritic cells…. Studies in humans document similar finding, where chronic exposure to low doses of elemental mercury or mercuric salt results in excessive T cell activation, increased serum IgE, and development of antinuclear antibodies [21 22 23 24 25 26]. 

Proinflammatory and regulatory cytokine production associated with innate and adaptive immune responses in children with autism spectrum disorders and developmental regression 

These cytokines appear to have been derived from microglial and astroglial cells and also implicate that disturbances of the innate immune system are relevant in ASD. 

• “ Developmental Regression and Mitochondrial Dysfunction in a Child With Autism”   : Autistic spectrum disorders can be associated with mitochondrial dysfunction. We present a singleton case of developmental regression and oxidative phosphorylation disorder in a 19-month-old girl…..

A 19-month-old girl was born after a normal full-term pregnancy. There was no family history of autism or affective, neuromuscular, or hearing disorders. Her development was progressing well, with normal receptive and expressive language and use of prelinguistic gestures, such as pointing for joint attention. Imaginary play and social reciprocity were typical for age. She used at least 20 words and could point to five body parts on command. Several immunizations were delayed owing to frequent bouts of otitis media with fever.

Within 48 hours after immunizations to diphtheria, tetanus, and pertussis; Haemophilus influenzae B; measles, mumps, and rubella; polio; and varicella (Varivax), the patient developed a fever to 38.9°C, inconsolable crying, irritability, and lethargy and refused to walk. Four days later, the patient was waking up multiple times in the night, having episodes of opistho-tonus, and could no longer normally climb stairs. Instead, she crawled up and down the stairs. Low-grade intermittent fever was noted for the next 12 days. Ten days following immunization, the patient developed a generalized erythematous macular rash beginning in the abdomen. The patient’s pediatrician diagnosed this as due to varicella vaccination. For 3 months, the patient was irritable and increasingly less responsive verbally, after which the patient’s family noted clear autistic behaviors, such as spinning, gaze avoidance, disrupted sleep/wake cycle, and perseveration on specific television programs. All expressive language was lost by 22 months.

•What happened to little, red-haired Hannah Poling is hardly unique in the world of autism. She had an uneventful birth; she seemed to be developing normally — smiling, babbling, engaging in imaginative play, speaking about 20 words by 19 months. And then, right after receiving a bunch of vaccines, she fell ill and it all stopped

Are these cases of vaccination and then regressive autism rare?  Hardly. Science is showing how the immune system and the microbiome are big clues.

• We report demographic and clinical characteristics of children reported to the US Vaccine Adverse Event Reporting System (VAERS) as having autism or another developmental disorder after vaccination. We completed 124 interviews with parents and reviewed medical records for 31 children whose records contained sufficient information to evaluate the child's developmental history. Medical record review indicated that 27 of 31 (87%) children had autism/ASD and 19 ( 61.3%) had evidence of developmental regression (loss of social, language, or motor skills). 

This line of important research is not new.  We will continue to report the truth:

• Primary gastrointestinal pathology may play an important role in the inception and clinical expression of some childhood developmental disorders, including autism. During the past 4 years, it has been my privilege to work with one of the finest pediatric gastroenterology teams in the world, headed by John Walker-Smith, on an innovative and challenging investigation of gastrointestinal pathology in children with autism. We believe that this work will provide new and important insights into the pathogenesis of this devastating condition. Although the primary causes of autism may be diverse, clues to the possible origin of the disease may be found in the history and clinical investigation of affected children. This talk focuses on the significance of gastrointestinal symptoms in autistic children, in particular, a subset of children for whom the clinical course is characterized by regression after at least 12 to 15 months of normal development.

The Gut–Brain Axis in Childhood Developmental Disorders , Wakefield, Andrew J. 2002 

 

Posted by Age of Autism at April 16, 2014 at 5:45 AM in Teresa Conrick Permalink

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