hypersensitivity

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. SYN: cell-mediated immunity. 2. SYN: delayed reaction. 3. a cell-mediated response that occurs in immune individuals peaking at 24–48 hours after challenge with the same antigen used in an initial challenge. The interaction of T-helper I lymphocytes with MHC class II positive antigen-presenting cells initiates the response. This interaction induces the T helper 1 and macrophages at the site to secrete cytokines, which are the major players in the reaction. Called tuberculin-type h..
- immediate h. an exaggerated immune response mediated by antibodies occurring within minutes after exposing a sensitized individual to the approximate antigen; also called Type I h.. Clinical symptoms include atopic allergy and systemic anaphylaxis. The antigen induces IgE antibodies, which bind to most cells and basophils. Subsequent exposure to antigen causes binding with the cytophilic IgE resulting in the release of mediators. See allergy.
- tuberculin-type h. SYN: delayed reaction.

* * *

hy·per·sen·si·tiv·i·ty (hi″pər-sen″sĭ-tivґĭ-te) a state of altered reactivity in which the body reacts with an exaggerated or inappropriate immune response to what is perceived to be a foreign substance. The resulting hypersensitivity reactions are usually subclassified as types I–IV on the basis of the Gell and Coombs classification of immune responses; see individual types under hypersensitivity reaction at reaction.

Medical dictionary. 2011.

Игры ⚽ Поможем написать реферат

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 — 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… …   Dictionary of molecular biology

  • 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”