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Autoimmune Disorders


Peter J. Delves

, PhD, University College London, London, UK

Last full review/revision Oct 2020| Content last modified Oct 2020

An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues.

  • What triggers autoimmune disorders is not known.
  • Symptoms vary depending on which disorder develops and which part of the body is affected.
  • Several blood tests are often used to check for an autoimmune disorder.
  • Treatment depends on the type of autoimmune disorder and often involves drugs that suppress the activity of the immune system.

(See also Overview of Allergic Reactions.)

The immune system must first recognize foreign or dangerous substances before it can defend the body against them. Such substances include bacteria, viruses, parasites (such as worms), certain cancer cells, and even transplanted organs and tissues. These substances have molecules that the immune system can identify and that can stimulate a response by the immune system. These molecules are called antigens. Antigens may be contained within cells or on the surface of cells (such as bacteria or cancer cells) or be part of a virus. Some antigens, such as pollen or food molecules, exist on their own.

Cells in a person's own tissues also have antigens. But normally, the immune system reacts only to antigens from foreign or dangerous substances, not to antigens from a person's own tissues. However, the immune system sometimes malfunctions, interpreting the body's own tissues as foreign and producing antibodies (called autoantibodies) or immune cells that target and attack particular cells or tissues of the body. This response is called an autoimmune reaction. It results in inflammation and tissue damage. Such effects may constitute an autoimmune disorder, but many people produce such small amounts of autoantibodies that an autoimmune disorder does not occur. Having autoantibodies in the blood does not mean that a person has an autoimmune disorder.

There are many autoimmune disorders. Some of the more common autoimmune disorders include Graves disease, rheumatoid arthritis, Hashimoto thyroiditis, type 1 diabetes mellitus, systemic lupus erythematosus (lupus), and vasculitis. Additional disorders that are believed to be autoimmune include Addison disease, polymyositis, Sjögren syndrome, progressive systemic sclerosis, many cases of glomerulonephritis (inflammation of the kidneys), and some cases of infertility.

Some Autoimmune Disorders


Main Tissues Affected


Autoimmune hemolytic anemia

Red blood cells

Anemia (decreased number of red blood cells) develops, causing fatigue, weakness, and light-headedness.

The spleen may enlarge.

The anemia can be severe and even fatal.

Bullous pemphigoid


Large blisters, surrounded by red, swollen areas, form on the skin. Itching is common.

The disorder affects mainly older people and can be life threatening, especially in older people who have other disorders.

Diabetes mellitus, type 1

Beta cells of the pancreas (which produce insulin)

Symptoms may include excessive thirst, urination, and appetite, as well as various long-term complications.

Lifelong treatment with insulin is needed, even if the destruction of pancreatic cells stops, because not enough pancreatic cells remain to produce enough insulin.

The prognosis varies greatly and tends to be worse when the disease is severe and lasts a long time.

Goodpasture syndrome

Lungs and kidneys

Symptoms, such as shortness of breath, coughing up blood, fatigue, and swelling, may develop.

The prognosis is good if treatment begins before severe lung or kidney damage occurs.

Graves disease

Thyroid gland

The thyroid gland is stimulated and enlarged, resulting in high levels of thyroid hormones (hyperthyroidism).

Symptoms may include a rapid heart rate, intolerance of heat, tremor, weight loss, and nervousness.

With treatment, the prognosis is good.

Hashimoto thyroiditis

Thyroid gland

The thyroid gland is inflamed and damaged, resulting in low levels of thyroid hormones (hypothyroidism).

Symptoms may include weight gain, coarse skin, intolerance of cold, and drowsiness.

Lifelong treatment with thyroid hormone is necessary and usually relieves the symptoms completely.

Multiple sclerosis

Brain and spinal cord

The covering of affected nerve cells is damaged. As a result, the cells cannot conduct nerve signals normally.

Symptoms may include weakness, abnormal sensations, vertigo, problems with vision, muscle spasms, and incontinence. Symptoms vary over time and may come and go.

The prognosis varies.

Myasthenia gravis

The connection between nerves and muscles (neuromuscular junction)

Muscles, particularly those of the eyes, weaken and tire easily, but the weakness varies in intensity. The pattern of progression varies widely.

Drugs can usually control the symptoms.

Pemphigus vulgaris


Large blisters form on the skin and mucous membranes (such as those lining of the mouth).

The disorder can be life threatening if untreated.

Pernicious anemia

Certain cells in the stomach's lining

Damage to cells in the stomach's lining makes absorbing vitamin B12 difficult. (Vitamin B12 is necessary for the production of mature blood cells and the maintenance of nerve cells.) Anemia results, often causing fatigue, weakness, and light-headedness. Nerves can be damaged, resulting in weakness and loss of sensation.

Without treatment, the spinal cord may be damaged, eventually contributing to loss of sensation, weakness, and incontinence.

The risk of stomach cancer is increased. Otherwise, with treatment, the prognosis is good.

Rheumatoid arthritis

Joints or other tissues, such as lung, nerve, skin, and heart tissue

Many symptoms are possible. They include fever, fatigue, joint pain, joint stiffness, deformed joints, shortness of breath, loss of sensation, weakness, rashes, chest pain, and swollen joints and tendons.

The prognosis varies.

Systemic lupus erythematosus (lupus)

Joints, kidneys, skin, lungs, heart, brain, and blood cells

The joints, although inflamed, do not become deformed.

Symptoms of anemia, such as fatigue, weakness, and light-headedness, and those of kidney, lung, or heart disorders, such as fatigue, shortness of breath, itching, and chest pain, may occur.

A rash may develop.

Hair loss is common.

The prognosis varies widely, but most people can lead an active life despite occasional flare-ups of lupus.


Blood vessels

Vasculitis can affect blood vessels in one part of the body (such as the nerves, head, skin, kidneys, lungs, or intestine) or several parts. There are several types.

Symptoms (such as rashes, abdominal pain, weight loss, difficulty breathing, cough, chest pain, headache, loss of vision, and symptoms of nerve damage or kidney failure) depend on which part of the body is affected.

The prognosis depends on the cause and how much tissue is damaged. Usually, the prognosis is much better with treatment.

Causes of Autoimmune Disorders

Autoimmune reactions can be triggered in several ways:

  • A normal body substance is altered, for example, by a virus, a drug, sunlight, or radiation. The altered substance may appear foreign to the immune system. For example, a virus can infect and thus alter cells in the body. The virus-infected cells stimulate the immune system to attack.
  • A foreign substance that resembles a natural body substance may enter the body. The immune system may inadvertently target the similar body substance as well as the foreign substance. For example, the bacteria that cause strep throat have an antigen that is similar to an antigen in human heart cells. Rarely, the immune system attacks a person's heart after strep throat (this reaction is part of rheumatic fever).
  • The cells that control antibody production—for example, B cells (a type of white blood cell)—may malfunction and produce abnormal antibodies that attack some of the body's cells.
  • A substance in the body that is normally confined to a specific area (and thus is hidden from the immune system) is released into the bloodstream. For example, a blow to the eye can cause the fluid in the eyeball to be released into the bloodstream. The fluid stimulates the immune system to identify the eye as foreign and attack it.

Why something triggers an autoimmune reaction or disorder in one person (and not another) is usually unknown. However, heredity is sometimes involved. Some people have genes that make them slightly more likely to develop an autoimmune disorder. This slightly increased susceptibility to an autoimmune disorder, rather than the disorder itself, is inherited. In susceptible people, a trigger, such as a viral infection or tissue damage, may cause the disorder to develop.

Many autoimmune disorders are more common among women.

Symptoms of Autoimmune Disorders

Symptoms vary depending on the disorder and the part of the body affected. Some autoimmune disorders affect certain types of tissue throughout the body—for example, blood vessels, cartilage, or skin. Other autoimmune disorders affect a particular organ. Virtually any organ, including the kidneys, lungs, heart, and brain, can be affected. The resulting inflammation and tissue damage can cause pain, deformed joints, weakness, jaundice, itching, difficulty breathing, accumulation of fluid (edema), delirium, and even death.

Diagnosis of Autoimmune Disorders

  • Blood tests
  • A doctor's evaluation

Blood tests that indicate the presence of inflammation may suggest an autoimmune disorder. Such tests include the following:

  • The erythrocyte sedimentation rate (ESR): This test measures how quickly red blood cells (erythrocytes) settle to the bottom of a test tube containing blood. When inflammation is present, the ESR is often increased because proteins that are produced in response to inflammation interfere with the ability of red blood cells to remain suspended in blood.
  • Complete blood count (CBC): This test includes determining the number of red blood cells in blood. This number is frequently decreased (anemia) because fewer red blood cells are produced when inflammation is present.

Because inflammation has many causes (many of which are not autoimmune), doctors often also do blood tests to detect different antibodies that can occur in people who have particular autoimmune disorders. Examples of these antibodies are

  • Antinuclear antibodies, which are typically present in systemic lupus erythematosus
  • Rheumatoid factor or anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are typically present in rheumatoid arthritis

But even these antibodies sometimes occur in people who do not have an autoimmune disorder, so doctors usually use a combination of test results and the person's symptoms to decide whether an autoimmune disorder is present.

Did You Know...

  • Some people have genes that make them slightly more likely to develop an autoimmune disorder.
  • Virtually any organ can be affected by an autoimmune disorder.

Prognosis of Autoimmune Disorders

Some autoimmune disorders resolve as inexplicably as they began. However, most autoimmune disorders are chronic. Drugs are often required throughout life to control symptoms.

The prognosis varies depending on the disorder.

Treatment of Autoimmune Disorders

  • Drugs that suppress the immune system, including corticosteroids
  • For some autoimmune disorders, plasma exchange and intravenous immune globulin

Drug treatment

Drugs that suppress the immune system (immunosuppressants), such as azathioprine, chlorambucil, cyclophosphamide, cyclosporine, mycophenolate, and methotrexate, are often given, usually by mouth and often for a long time. However, these drugs suppress not only the autoimmune reaction but also the body's ability to defend itself against foreign substances, including microorganisms that cause infection and cancer cells. Consequently, the risk of certain infections and cancers increases.

Often, corticosteroids, such as prednisone, are given, usually by mouth. These drugs relieve inflammation as well as suppress the immune system. Corticosteroids given for a long time have many side effects. When possible, corticosteroids are used for a short time—when the disorder begins or when symptoms worsen. However, corticosteroids must sometimes be used indefinitely.

Certain autoimmune disorders (such as multiple sclerosis and thyroid disorders) are also treated with drugs other than immunosuppressants and corticosteroids. Treatment to relieve symptoms may also be needed.

Etanercept, infliximab, and adalimumab block the action of tumor necrosis factor (TNF), a substance that can cause inflammation in the body. These drugs are very effective in treating rheumatoid arthritis and some other autoimmune disorders, but they may be harmful if used to treat certain other autoimmune disorders, such as multiple sclerosis. These drugs can also increase the risk of infection and certain skin cancers.

Certain drugs specifically target white blood cells. White blood cells help defend the body against infection but also participate in autoimmune reactions. These drugs include the following:

  • Abatacept blocks the activation of one kind of white blood cell (T cell) and is used in rheumatoid arthritis.
  • Rituximab, first used against certain white blood cell cancers, works by depleting certain white blood cells (B cells) from the body. It is effective in some autoimmune disorders, such as rheumatoid arthritis and certain disorders that cause inflammation of blood vessels (vasculitis), including granulomatosis with polyangiitis (formerly called Wegener granulomatosis). Rituximab is under study in a variety of other autoimmune disorders.

Other drugs that target white blood cells are being developed.

Plasma exchange and intravenous immune globulin

Plasma exchange is used to treat a few autoimmune disorders. Blood is withdrawn and filtered to remove abnormal proteins such as autoantibodies. Then the filtered blood is returned to the person.

Intravenous immune globulin (a purified solution of antibodies obtained from volunteer donors and given by vein) is used to treat a few autoimmune disorders. How it works is unknown.

Drugs Mentioned In This Article

Generic Name Select Brand Names
cyclophosphamide CYTOXAN (LYOPHILIZED)
immune globulin Gammagard S/D
mycophenolate Mycophenolate
chlorambucil LEUKERAN
azathioprine IMURAN
methotrexate OTREXUP
prednisone RAYOS
Rituximab RITUXAN

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