Chronic Inflammation and Autism Spectrum Disorders
For over a decade, reports have placed environmental factors at the center of the etiological framework for autism spectrum disorders. Most proposed perinatal risk factors appear to converge on activation of the immune system (Depino, 2013).
This aligns with an inflammatory response to exposure to toxic agents.
Furthermore, elevated plasma cytokine levels in individuals with autism spectrum disorders indicate immune dysfunction. These levels have been correlated with behavioral impairments (Ashwood, 2011, et al.).
Although focused on a specific aspect, the following study offers an extensive bibliography on chronic inflammation in autism spectrum disorders.
Carbone, Manduca, Cacchione, Vicari, Trezza. Healing autism spectrum disorder with cannabinoids: a neuroinflammatory story. Neuroscience & Biobehavioral Reviews, 2021, Vol. 121, 128-143,
For families
A number of researchers use the term « immunopsychiatry » to characterize autism spectrum disorders and various other psychiatric illnesses. Yet, related treatment strategies remain to be validated..
Autoimmune Hypothesis
Several studies suggest that exposure to bacterial metabolites (such as Borrelia, Chlamydia, and Mycoplasma), food-derived peptides (including gliadin and casein derivatives), and various toxins (e.g., methylmercury) may trigger an autoimmune response in children with autism.
However, to date, these findings have not been sufficiently substantiated by further research.
Reference :
Vojdani et al. Infections, Toxic Chemicals and Dietary Peptides Binding to Lymphocyte Receptors and Tissue Enzymes are Major Instigators of Autoimmunity in Autism. International Journal of Immunopathology and Pharmacology. September 2003:189-199
Infections: A Possible Trigger or Aggravating Factor?
Immune system abnormalities have been widely reported in children with autism, potentially increasing their susceptibility to childhood infections (Sabourin, 2019). Many autistic individuals present with bacterial, viral, and fungal infections that may affect both their overall health and behavior.
The presence of one or more infections may predispose autistic individuals to additional infections.
Some studies suggest that such infections—occurring either during pregnancy or in infancy—may act as triggers for the development of autism spectrum disorders (Zerbo, 2015; Patterson, 2011). Other research indicates that chronic infections may exacerbate autism symptoms.
Although the findings remain inconclusive, earlier studies offer significant insights and underscore the need for further investigation into the role of chronic infections.
Reference :
Nicolson et al, Evidence for Mycoplasma ssp., Chlamydia pneunomiae, and human herpes virus-6 coinfections in the blood of patients with autistic spectrum disorders, 2007, Journal of Neuroscience Research, Vol. 85, Issue 5, 1143-1148
Microbiome
In 2024, a team led by Angelica Ahrens published an interim report on the long-term follow-up of over 16,000 Swedish children over a period of approximately 20 years (please refer to the section concerning immunology).
This research follows a cohort known as All Babies in Southeast Sweden (ABIS). Nearly 1,200 of these children went on to develop neurodevelopmental disorders, including intellectual disability, language disorders, attention deficit/hyperactivity disorder (ADHD), and autism.
The study revealed correlations between an abnormal microbiome—both microbial composition and metabolic byproducts—and the onset of neurodevelopmental conditions. However, it is important to note that the findings are correlational in nature and do not establish causation.
Référence : Ahrens et al., Infant microbes and metabolites point to childhood neurodevelopmental disorders, 2024, Cell 187, 1853–1873 April 11, 2024 Published by Elsevier
