Clinical immunology is the study of diseases caused by the immune system and diseases of the immune system from a medical perspective. A disease is an abnormal condition of the body or mind that causes discomfort, dysfunction, or distress to the person afflicted or those in contact with the person. ...

Many diseases caused by the immune system fall into two broad categories: immunodeficiency, in which parts of the immune system fail to provide an adequate response (examples include chronic granulomatous disease), and autoimmunity, in which the immune system attacks its own antigens (examples include systemic lupus erythematosus, rheumatoid arthritis, Hashimoto's disease and myasthenia gravis). Other immune system disorders include different hypersensitivities, in which the system responds inappropriately to harmless compounds (asthma and allergies) or responds too intensively. In medicine, immune deficiency (or immunodeficiency) is a state where the immune system is incapable of defending the organism from infectious disease. ... In medicine (genetics and pediatrics) chronic granulomatous disease (CGD) is a hereditary disease where neutrophil granulocytes are unable to destroy ingested pathogens. ... Autoimmunity is the failure of an organism to recognise its own constituent parts (down to the sub-molecular levels) as Self, which results in an immune response against its own cells and tissues. ... Rheumatoid arthritis (RA) is a chronic, inflammatory autoimmune disorder that causes the immune system to attack the joints. ... Hashimotos thyroiditis is the most common form of thyroiditis, an autoimmune disease where the bodys own antibodies fight the cells of the thyroid. ... Myasthenia gravis (MG, Latin: grave muscle weakness) is a neuromuscular disease leading to fluctuating weakness and fatiguability. ... Hypersensitivity is an immune response that damages the bodys own tissues. ... An allergy or Type I hypersensitivity is an immune system malfunction whereby a persons body is hypersensitised to react immunologically to typically nonimmunogenic substances. ...

The most well-known disease that affects the immune system itself is AIDS, caused by the HIV virus. AIDS is an immunodeficiency characterized by the lack of CD4+ ("helper") T cells and macrophages, which are destroyed by the HIV virus. AIDS (Acquired Immunodeficiency Syndrome or Acquired Immune Deficiency Syndrome, sometimes written Aids) is a human disease characterized by progressive destruction of the bodys immune system. ... The human immunodeficiency virus (HIV) is a frequently mutating retrovirus that attacks the human immune system and which has been shown to cause acquired immune deficiency syndrome (AIDS). ... T cells are a subset of lymphocytes that play a large role in the immune response. ... Macrophages (Greek: big eaters) are cells found in tissues that are responsible for phagocytosis of pathogens, dead cells and cellular debris. ...

Clinical immunologists also study ways to prevent transplant rejection, in which the immune system attempts to destroy allografts or xenografts. Transplant rejection occurs when the immune system of the recipient of an transplant attacks the transplanted organ or tissue. ... An allograft is a transplanted organ or tissue from a genetically non-identical member of the same species. ... A xenograft (xenotransplant) is a transplant of tissue from a donor of one species to a recipient of another species. ...

See also

• Immune system
• Immunology

The immune system is the system of specialized cells and organs that protect an organism from outside biological influences. ... Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. ...

External links

• Clinical Immunology Society