Definition: Defining the Meaning of Autoimmune Disease
Autoimmune diseases arise from an abnormal immune response of the body against substances and tissues normally present in the body (autoimmunity). Your body's immune system protects you from disease and infection. But if you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake. Autoimmune diseases can affect many parts of the body. The exact cause of autoimmune disorders is unknown. One theory is that some micro-organisms (such as bacteria or viruses) or drugs may trigger changes that confuse the immune system.
Our bodies have an immune system that protects us from disease and infection. But if you have an autoimmune disease, your immune system attacks itself by mistake.
Normally the immune system's army of white blood cells helps protect the body from harmful substances, called antigens. Examples of antigens include bacteria, viruses, toxins, cancer cells, and foreign blood or tissues from another person or species. The immune system produces antibodies that destroy these harmful substances.
- There are more than 80 illnesses caused by autoimmunity.
- A substantial minority of the population suffers from these diseases, which are often chronic, debilitating, and life-threatening.
- It has been estimated that autoimmune diseases are among the top ten leading causes of death among women in all age groups up to 65 years.
Autoimmune diseases arise from an over-active immune response of the body against substances and tissues normally present in the body. In other words, the body attacks its own cells. This may be restricted to certain organs (e.g. in thyroiditis) or involve a particular tissue in different places (e.g. Goodpasture's disease which may affect the basement membrane in both the lung and the kidney).
Autoimmune disorders are classified into two types, organ-specific (directed mainly at one organ) and non-organ-specific (widely spread throughout the body).
An autoimmune disorder may result in:
- Changes in organ function
- Abnormal growth of an organ
- The destruction of body tissue
An autoimmune disorder may affect one or more organ or tissue types. Areas often affected by autoimmune disorders include:
- Blood vessels
- Red blood cells
- Connective tissues
- Endocrine glands such as the thyroid or pancreas
Nearly 79% of autoimmune disease patients in the USA are women. Also they tend to appear during or shortly after puberty. It is not known why this is the case, although hormone levels have been shown to affect the severity of some autoimmune diseases such as multiple sclerosis.
The treatment of autoimmune diseases is typically with immuno-suppression - medication which decreases the immune response.
Autoimmune disorders can also have flare-ups, when they get worse, and remissions, when symptoms get better or disappear. Treatment depends on the disease, but in most cases one important goal is to reduce inflammation. Sometimes doctors prescribe corticosteroids or other drugs that reduce your immune response.
Treatments your doctor suggests will depend on your disease and symptoms. Types of treatments include:
- Blood transfusions if blood is affected
- Physical therapy to help with movement if the bones, joints, or muscles are affected
- Supplements to replace a substance that the body lacks, such as thyroid hormone, vitamin B12, or insulin, due to the autoimmune disease
Many people take medicines to reduce the immune system's abnormal response. These are often called immunosuppressive medicines. Examples include corticosteroids (such as prednisone) and non-steroid drugs such as azathioprine, cyclophosphamide, mycophenolate, sirolimus, or tacrolimus.
Quick Facts: Types of Autoimmune Diseases
There are more than 80 types of autoimmune diseases.
|Autoimmune Diseases Include:|
|Acute disseminated encephalomyelitis|
|Antiphospholipid antibody syndrome|
|Autoimmune hemolytic anemia|
|Autoimmune inner ear disease|
|Chronic obstructive pulmonary disease|
|Diabetes mellitus type 1|
|Idiopathic thrombocytopenic purpura|
|Mixed Connective Tissue Disease|
|Primary biliary cirrhosis|