About Autoimmune Diseases
In healthy people, the immune system works like a vigilant defense squad, always on the lookout for foreign invaders like bacteria and viruses that threaten your health. Once invaded, the immune system goes to work, generating substances called antibodies, which go on the attack against the invaders, or antigens. The white blood cells work feverishly to destroy the invaders and bring about healing.
In someone who has an autoimmune disease, these white blood cells are mysteriously summoned for no apparent reason, and the body mistakenly treats normal healthy tissue as something foreign. The body then begins to produce antibodies against the perceived invader. Antibodies produced in an autoimmune disease are known as autoantibodies. In people with Hashimoto's, the most common antibodies are the thyroid peroxidase antibodies (TPOAb). These are the same antibodies that cause Graves' disease, which we will discuss in Chapter 9.
Though they may occur simultaneously, Hashimoto's thyroiditis is not the same thing as Hashimoto's encephalopathy, a rare autoimmune disease in which antibodies attack neurons in the brain. The same antibodies — anti- TPO — are involved in both conditions, and both conditions were identified by the same doctor. With Hashimoto's encephalopathy, you may experience dementia, tremors, headaches, and partial paralysis. It is sometimes mistaken for Alzheimer's, but it is treatable with steroids. Fortunately, Hashimoto's encephalopathy is rare.
An autoimmune attack can occur in various organs and body systems, each causing its own disease and constellation of symptoms. Antibodies that attack connective tissue cause systemic lupus erythematosus. Those that harm the joints cause rheumatoid arthritis. Those that target the tissues of the thyroid gland cause Hashimoto's thyroiditis, named for the Japanese surgeon who first identified the disease in 1912.