Autoimmune disease causes the immune system to mistakenly attack the body's own healthy cells and tissues. Instead of protecting the body from foreign invaders like bacteria and viruses, it targets healthy cells as if they were threats.
Here's a breakdown of how autoimmune diseases impact the immune system:
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Misdirected Immune Response: The primary effect is a loss of self-tolerance. The immune system fails to distinguish between "self" (the body's own cells) and "non-self" (foreign invaders). This leads to the production of autoantibodies (antibodies that attack the body's own tissues) and autoreactive T cells (T cells that attack the body's own tissues).
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Chronic Inflammation: The immune system's attack on the body's own tissues triggers chronic inflammation. This inflammation can damage organs and tissues over time, leading to various symptoms depending on the specific autoimmune disease.
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Tissue Damage: The sustained attack by the immune system leads to damage of specific organs and tissues. For example:
- In rheumatoid arthritis, the immune system attacks the lining of the joints, causing inflammation, pain, and eventually joint damage.
- In type 1 diabetes, the immune system attacks the insulin-producing cells in the pancreas.
- In multiple sclerosis, the immune system attacks the myelin sheath that protects nerve fibers in the brain and spinal cord.
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Increased Immune Activity: Individuals with autoimmune diseases often have an overactive immune system. This means the immune system is more easily triggered and reacts more strongly than it should. This heightened activity contributes to the ongoing attack on the body's own tissues.
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Production of Autoantibodies: A hallmark of many autoimmune diseases is the presence of autoantibodies. These are antibodies that mistakenly target and bind to the body's own proteins or tissues. The presence of specific autoantibodies can often be used to diagnose autoimmune diseases.
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Impact on Immune Cells: Autoimmune diseases can affect different types of immune cells, including:
- B cells: Produce autoantibodies.
- T cells: Some T cells become autoreactive and directly attack the body's tissues. Regulatory T cells, which normally suppress the immune response, may be dysfunctional in autoimmune diseases, further contributing to the loss of self-tolerance.
In essence, autoimmune diseases disrupt the normal functioning of the immune system, causing it to become a threat to the body it is supposed to protect. The immune system's misplaced aggression leads to chronic inflammation and tissue damage, resulting in a range of debilitating symptoms and health complications.
