Biomarkers & ASD
A half-day symposium providing insight into research and current trials that point to the potential benefit of medical treatments to address environmentally-triggered impairments associated with autism spectrum disorders.
Recorded June 1, 2013 at UC Davis MIND Institute Auditorium in Sacramento, California. Videos are courtesy of Autism Research Institute, UC Davis MIND Institute & Autism Speaks.
Is There a Connection Between the Immune System and Autism?
The ideal immune system will:
- Recognize all foreign organisms (bacteria, viruses, parasites, fungi, worms).
- Efficiently and rapidly destroy invaders.
- Prevent a second infection with the same microbe (have a good memory).
- Never cause damage to self.
Things that can go wrong:
- Immune deficiency/dysfunction: defective or ineffective response.
- Hypersensitivity: Over-reaction to innocuous foreign material, out of proportion to potential damage (allergy).
- Autoimmunity: Inappropriate reaction towards self, loss of self-recognition.
- Inflammation: Too-vigorous attack against invaders with “bystander” damage to normal tissue.
Dysregulation of immunity in people with autism can lead to any of these four problems.
There is a tendency towards a positive family history of autoimmunity in families – Rheumatoid Arthritis, Thyroiditis – with an ASD child. Many, many types of autoantibodies (against “self” tissues) have been found in ASD children but the significance of the many types of anti-brain antibodies is not yet clear. Several studies find that some ASD children have low immunoglobulins (IgG, IgM, IgA), and/or low T cell numbers, altered cytokine profiles, and/or low-normal functioning and/or low NK cells; a subset of children have true immunodeficiency. Some children have low serum IgA, predisposing them to respiratory and GI infections.
Antibodies are divided up into classes:
- IgA: Mucosal surfaces – if this is low, it predisposes to respiratory and GI infections as well as autoimmunity; it is sometimes low in ASD children
- IgM: Rapid response bloodstream antibody made at the beginning of an infection; can be high or low in ASD
- IgG: Slower but longer lasting bloodstream antibody; can be high or low in ASD
- IgE: Allergy; can be high or normal in ASD
Conclusion #1: A child on the autism spectrum with recurrent infections deserves an immune evaluation for immunodeficiency.
Conclusion #2: A child on the autism spectrum with eczema, chronic nasal symptoms, asthma, significant GI symptoms, or recurrent respiratory infections deserves an allergy evaluation for IgE inhalant and food allergies.