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X-ray and photo of hands with joints bent at unusual angles.
The radiograph (left) and photograph (right) show damage to the hands typical of rheumatoid arthritis. (credit right: modification of work by “handarmdoc”/Flickr)

Systemic lupus erythematosus

The damage and pathology of systemic lupus erythematosus (SLE) is caused by type III hypersensitivity reactions. Autoantibodies produced in SLE are directed against nuclear and cytoplasmic proteins. Anti-nuclear antibodies (ANAs) are present in more than 95% of patients with SLE, C.C. Mok, C.S. Lau. “Pathogenesis of Systemic Lupus Erythematosus.” Journal of Clinical Pathology 56 no. 7 (2003):481—490. with additional autoantibodies including anti-double–stranded DNA (ds-DNA) and anti-Sm antibodies (antibodies to small nuclear ribonucleoprotein). Anti-ds-DNA and anti-Sm antibodies are unique to patients with SLE; thus, their presence is included in the classification criteria of SLE. Cellular interaction with autoantibodies leads to nuclear and cellular destruction, with components released after cell death leading to the formation of immune complexes.

Because autoantibodies in SLE can target a wide variety of cells, symptoms of SLE can occur in many body locations. However, the most common symptoms include fatigue, fever with no other cause, hair loss, and a sunlight-sensitive "butterfly" or wolf-mask (lupus) rash that is found in about 50% of people with SLE ( [link] ). The rash is most often seen over the cheeks and bridge of the nose, but can be widespread. Other symptoms may appear depending on affected areas. The joints may be affected, leading to arthritis of the fingers, hands, wrists, and knees. Effects on the brain and nervous system can lead to headaches, numbness, tingling, seizures, vision problems, and personality changes. There may also be abdominal pain, nausea, vomiting, arrhythmias, shortness of breath, and blood in the sputum. Effects on the skin can lead to additional areas of skin lesions, and vasoconstriction can cause color changes in the fingers when they are cold (Raynaud phenomenon). Effects on the kidneys can lead to edema in the legs and weight gain. A diagnosis of SLE depends on identification of four of 11 of the most common symptoms and confirmed production of an array of autoantibodies unique to SLE. A positive test for ANAs alone is not diagnostic.

a) Diagram of symptoms include: a rash on the phase, ulcers of the nose and mouth, muscle aches, inflammation of the pericardium (heart region), poor circulation in the fingers and toes. B) photo of a butterfly rash on the face.
(a) Systemic lupus erythematosus is characterized by autoimmunity to the individual’s own DNA and/or proteins. (b) This patient is presenting with a butterfly rash, one of the characteristic signs of lupus. (credit a: modification of work by Mikael Häggström; credit b: modification of work by Shrestha D, Dhakal AK, Shiva RK, Shakya A, Shah SC, Shakya H)
  • List the ways antibodies contribute to the pathogenesis of myasthenia gravis.
  • Explain why rheumatoid arthritis is considered a type III hypersensitivity.
  • Describe the symptoms of systemic lupus erythematosus and explain why they affect so many different parts of the body.
  • What is recognized as an antigen in myasthenia gravis?

[link] summarizes the causes, signs, and symptoms of select autoimmune diseases.

Select Autoimmune Diseases
Disease Cause Signs and Symptoms
Addison disease Destruction of adrenal gland cells by cytotoxic T cells Weakness, nausea, hypotension, fatigue; adrenal crisis with severe pain in abdomen, lower back, and legs; circulatory system collapse, kidney failure
Celiac disease Antibodies to gluten become autoantibodies that target cells of the small intestine Severe diarrhea, abdominal pain, anemia, malnutrition
Diabetes mellitus (type I) Cytotoxic T-cell destruction of the insulin-producing β cells of the pancreas Hyperglycemia, extreme increase in thirst and urination, weight loss, extreme fatigue
Graves disease Autoantibodies target thyroid-stimulating hormone receptors, resulting in overstimulation of the thyroid Hyperthyroidism with rapid and irregular heartbeat, heat intolerance, weight loss, goiter, exophthalmia
Hashimoto thyroiditis Thyroid gland is attacked by cytotoxic T cells, lymphocytes, macrophages, and autoantibodies Thyroiditis with goiter, cold intolerance, muscle weakness, painful and stiff joints, depression, memory loss
Multiple sclerosis (MS) Cytotoxic T-cell destruction of the myelin sheath surrounding nerve axons in the central nervous system Visual disturbances, muscle weakness, impaired coordination and balance, numbness, prickling or “pins and needles” sensations, impaired cognitive function and memory
Myasthenia gravis Autoantibodies directed against acetylcholine receptors within the neuromuscular junction Extreme muscle weakness eventually leading to fatal respiratory arrest
Psoriasis Cytokine activation of keratinocytes causes rapid and excessive epidermal cell turnover Itchy or sore patches of thick, red skin with silvery scales; commonly affects elbows, knees, scalp, back, face, palms, feet
Rheumatoid arthritis Autoantibodies, immune complexes, complement activation, phagocytes, and T cells damage membranes and bone in joints Joint inflammation, pain and disfigurement, chronic systemic inflammation
Systemic lupus erythematosus (SLE) Autoantibodies directed against nuclear and cytoplasmic molecules form immune complexes that deposit in tissues. Phagocytic cells and complement activation cause tissue damage and inflammation Fatigue, fever, joint pain and swelling, hair loss, anemia, clotting, a sunlight-sensitive "butterfly" rash, skin lesions, photosensitivity, decreased kidney function, memory loss, confusion, depression

Summary

  • Autoimmune diseases result from a breakdown in immunological tolerance. The actual induction event(s) for autoimmune states are largely unknown.
  • Some autoimmune diseases attack specific organs, whereas others are more systemic.
  • Organ-specific autoimmune diseases include celiac disease , Graves disease , Hashimoto thyroiditis , type I diabetes mellitus, and Addison disease .
  • Systemic autoimmune diseases include multiple sclerosis , myasthenia gravis , psoriasis , rheumatoid arthritis , and systemic lupus erythematosus .
  • Treatments for autoimmune diseases generally involve anti-inflammatory and immunosuppressive drugs.

Fill in the blank

The thyroid-stimulating immunoglobulin that acts like thyroid-stimulating hormone and causes Graves disease is an antibody to the ________.

thyroid-stimulating hormone receptor

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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