hypersensitivity

hypersensitivity
In immunology, a state of excessive and potentially damaging immune responsiveness as a result of previous exposure to antigen. If the hypersensitivity is of the immediate type (antibody-mediated), then the response occurs in minutes; in delayed hypersensitivity the response takes much longer (about 24h) and is mediated by primed T-cells. Hypersensitivity responses are not simply divisible into the two types, and it is now more common to subdivide immediate responses into types I, II, and III, the delayed response being of type IV. Type I responses involve antigen reacting with IgE fixed to cells (usually mast cells) and are characterized by histamine release; anaphylactic responses and urticaria are of this type. In type II responses circulating antibody reacts with cell surface or cell-bound antigen, and if complement fixation occurs, cytolysis may follow. In type III reactions immune complexes are formed in solution and lead to damage (serum sickness, glomerulonephritis, Arthus reaction). Delayed-type responses of Type IV involve primed lymphocytes reacting with antigen and lead to formation of a lymphocyte-macrophage granuloma without involvement of circulating antibody.

Dictionary of molecular biology. 2004.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • hypersensitivity — hypersensitivity. См. гиперчувствительность. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Hypersensitivity — NOTOC Infobox Disease Name = PAGENAME Caption = DiseasesDB = 28827 ICD10 = ICD10|T|78|4|t|66 ICD9 = ICD9|995.3 ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = MeshID = D006967 Hypersensitivity (also called hypersensitivity reaction)… …   Wikipedia

  • hypersensitivity — Abnormal sensitivity, a condition in which there is an exaggerated response by the body to the stimulus of a foreign agent. See allergy. contact h. 1. SYN: contact dermatitis. 2. SYN: delayed reaction. delayed h. 1 …   Medical dictionary

  • hypersensitivity — See hypersensitiveness. * * *       acquired bodily state in which the reaction to a stimulus (e.g., a substance causing allergy or a physical agent such as light) is unusually prompt or excessive. The term hypersensitivity is often used as a… …   Universalium

  • hypersensitivity — superjautrumas statusas T sritis augalininkystė apibrėžtis Labai greitas augalo ląstelių su patekusiu virusu arba grybų hifais žuvimas, dėl kurio patogenas izoliuojamas ir negali toliau augale plisti. atitikmenys: angl. hypersensitivity rus.… …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • hypersensitivity — noun 1. pathological sensitivity • Derivationally related forms: ↑hypersensitive • Hypernyms: ↑sensitivity, ↑predisposition • Hyponyms: ↑cryesthesia, ↑cryaesthesia, ↑ …   Useful english dictionary

  • Hypersensitivity pneumonitis — Classification and external resources Micrograph of hypersensitivity pneumonitis. Lung biopsy. Trichrome stain …   Wikipedia

  • Hypersensitivity vasculitis — Infobox Disease Name = PAGENAME Caption = DiseasesDB = 7423 ICD10 = ICD10|M|31|0|m|30 ICD9 = ICD9|446.2 ICDO = OMIM = MedlinePlus = eMedicineSubj = med eMedicineTopic = 2930 MeshID = D018366 Hypersensitivity vasculitis (or hypersensitivity… …   Wikipedia

  • hypersensitivity vasculitis — 1. a group of systemic necrotizing vasculitides thought to represent hypersensitivity to an antigenic stimulus, such as a drug, infectious agent, or exogenous or endogenous protein; all disorders in this group involve the small vessels. Types… …   Medical dictionary

  • hypersensitivity myocarditis — myocarditis due to allergic reactions caused by hypersensitivity to various agents, particularly sulfonamides, penicillins, and methyldopa. It is characterized by interstitial infiltration, principally perivascular, by lymphocytes, plasma cells,… …   Medical dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”