Joint pain. Not an uncommon problem as you grow older. Is it due to normal wear and tear on the joints? Possibly. But rheumatoid arthritis is an autoimmune disease, which means the body's immune system mistakenly attacks healthy tissue.
Autoimmune diseases occur when the immune system fails to recognize the body’s own molecules as “self,” or belonging to the person. Instead, it attacks body cells as though they were dangerous pathogens. There are more than 80 known autoimmune diseases. Recall that regulatory T cells help regulate the immune system. When autoimmune disorders occur, these regulatory T cells fail in their function. This results in damage to various organs and tissues. The type of autoimmune disorder depends on the type of body tissue that is affected.
Some relatively common autoimmune diseases are listed in Table below. These diseases cannot be cured, although they can be treated to relieve symptoms and prevent some of the long-term damage they cause.
|Name of Disease||Tissues Attacked by Immune System||Results of Immune System Attack|
|Rheumatoid arthritis||tissues inside joints||joint damage and pain|
|Type 1 diabetes||insulin-producing cells of the pancreas||inability to produce insulin, high blood sugar|
|Multiple sclerosis||myelin sheaths of central nervous system neurons||muscle weakness, pain, fatigue|
|Systemic lupus erythematosus||joints, heart, other organs||joint and organ damage and pain|
Why does the immune system attack body cells? In some cases, it’s because of exposure to pathogens that have antigens similar to the body’s own molecules. When this happens, the immune system not only attacks the pathogens, it also attacks body cells with the similar molecules.
- Autoimmune diseases occur when the immune system fails to distinguish self from non-self. As a result, the immune system attacks the body’s own cells.
- What is an autoimmune disease? Name an example.
- Rheumatic fever is caused by a virus that has antigens similar to molecules in human heart tissues. When the immune system attacks the virus, it may also attack the heart. What type of immune system disease is rheumatic fever? Explain your answer.
- Can autoimmune disease be cured?