Compared to neurotypical individuals, a number of differences were found in individuals with ASD. These are a variety of disorders: reduced immunity and weakened defenses, or in contrast, the child may show an exaggerated immune response. It has been established that in the blood of individuals with autism, there are changes in the function of white blood cells, which are involved in the functioning of the immune system, as well as differences in the levels of substances related to immunity – antibodies or cytokines. Antibodies to one’s own cells and tissues have been found to be more common, and there is an increased risk of developing autoimmune diseases such as type 1 diabetes mellitus, psoriasis or Crohn’s disease. These diseases often do not manifest themselves until adulthood.

People with ASD are more likely to suffer from allergies, especially allergic rhinitis or food allergies; asthma or atopic eczema may be present. Symptoms of allergies such as breathing problems or itching can cause the child to have difficulty sleeping, resulting in inattention, irritability or hyperactivity. They may also result in worsening of the core symptoms of ASD.

Increased inflammatory activity has been reported in some children with ASD. Inflammation can affect the digestive system, adversely affect the intestinal microbiota and contribute to digestive problems. There are studies that have shown increased inflammatory activity in the brains of children with ASD, which is considered to be one of the possible contributing mechanisms in the development of ASD.

If an immune disorder is suspected, the child should be monitored by an immuno-allergist. Treatment can alleviate the symptoms of allergies or other immune disorders, which can lead to an adjustment in the child’s behavior as well as to increased quality of sleep.