Autism is not currently classified as an autoimmune disease, but there are factors involved that show immune system imbalances are a contributing problem. This article will discuss the link between autism and various brain tissues that relate to autoimmune reactivity and neurological inflammation.
Evidence exists that autism in certain individuals is connected to underlying medical problems,
including, but not limited to immune system disorders. One particular immune problem is autoimmunity. An autoimmune disorder is when the immune system attacks our own body tissue creating localized inflammation and cellular changes. There are a variety of autoimmune diseases such as Scleroderma, Rheumatoid Arthritis or Lupus. Autism is not currently classified as an autoimmune disease, but there are factors involved that show immune system imbalances are a contributing problem. This article will discuss the link between autism and various brain tissues that relate to autoimmune reactivity and neurological inflammation.
The Blood Brain Barrier:
The blood-brain barrier (BBB) is the biological barrier that protects the brain by regulating the flow of potential harmful substances, i.e. bacteria, viruses, toxins, growth factors, circulating ions (sodium, potassium, chloride) into the brain.
The BBB is made of up of a continuous layer of endothelial cells (blood vessels) that are joined together by connections called “tight junctions.” Tight junctions are analogous to the tight junctions in the digestive tract that only allow certain substances to pass through the wall of the gut into the bloodstream.
Just like in the digestive tract when there is a loss of tight junction function from things like intestinal inflammation called “leaky gut”, a similar situation can occur in the brain. With ongoing neurological inflammation we can develop a leaky BBB.
There are two important cellular components of the BBB – astroglia and microglia:
Astroglia (glial cell) – these cells are critical for brain and BBB function. They assist with brain nutrient absorption and structural support, as well as helping in repairing damaged areas. Astroglia can become over-stimulated leading to enlargement and crowding. This can cause hypoperfusion (reduced blood flow) in the brain.
Microglia (glial cell) – microglia compose approximately 20% of the glial cells in the brain. They are the main immune defense of the central nervous system, and are constantly on the hunt looking for invading pathogens. Microglia are responsible for initiating inflammation in response to infections and other immune triggers such as vaccines, foods, or endogenous end exogenous toxins. They can become chronically activated and never turn off which unfortunately leads to ongoing neurological damage.
In a 2005 study by Vargas, et al. and corresponding research article from the Department of Neurology at John Hopkins University titled “Neuroglial Activation and Neuroinflammation in the Brain of Patients with Autism” they discovered that individuals with ASD age 5 to 44 had significantly elevated levels of immune factors related to microglia induced inflammation.
In summary, the Vargas, et al. report stated “Our findings indicate that innate neuroimmune reactions play a pathogenic role in an undefined proportion of autistic patients, suggesting that future therapies might involve modifying neuroglial responses in the brain.”
Microglia are predisposed to become activated through various mechanisms. One example of these mechanisms is microglia activation induced by inflammation triggers that can occur via infections such as viruses and bacteria, as well as direct neurological damage from chemical exposure, heavy metal poisons, adverse vaccine reactions, and others. The process of neurological inflammation in certain individuals with autism gets set in place and can chronically cycle if the offending agent is not eliminated or the mechanism for autoimmune inflammation is not turned-off.
