Definition of reagin in English:

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Pronunciation: /rɪˈeɪdʒɪn/


[mass noun] Medicine
1The antibody which is involved in allergic reactions, causing the release of histamine when it combines with antigen in tissue, and capable of producing sensitivity to the antigen when introduced into the skin of a normal individual.
Example sentences
  • The mother was O Rh-positive, antibody screen negative, rapid plasma reagin nonreactive, hepatitis B surface antigen negative.
  • An 18-year-old woman presented for her first prenatal visit at 31 weeks' gestation, at which time she was reactive for rapid plasmin reagin and had a 2 + fluorescent treponemal antibody.
  • An infant born to a seroreactive mother should be evaluated with a quantitative non-treponemal serologic test (e.g., rapid plasma reagin or VDRL).
1.1The substance in the blood which is responsible for a positive response to the Wassermann test: [as modifier]: a reagin test [count noun]: reagins are measured by either complement fixation or flocculation tests
More example sentences
  • The patient's angiotensin-converting enzyme level was slightly elevated, and the rapid plasma reagin test was nonreactive.
  • The rapid plasmin reagin test was negative.
  • This reaction is the basis of traditional nontreponemal tests such as the VDRL test and rapid plasma reagin test.



Example sentences
  • For example, foods induce respiratory symptoms by both reaginic and nonreaginic mechanisms; moreover, food allergies commonly coexist with inhalant allergies.
  • Reaginic reactions are responsible for such allergic phenomena as urticaria, seasonal rhinitis, and asthma.
  • Mice produced reaginic antibody within 1 wk of painting with the contact sensitizing agent picryl chloride.


Early 20th century: coined in German from reagieren 'react'.

For editors and proofreaders

Line breaks: re¦agin

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