Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Interferon gamma release assay
open-in-new
<p>Interferon-γ release assays (IGRA) are medical tests used in the diagnosis of some infectious diseases, especially <a href="/facts/Tuberculosis/ggPyovAl">tuberculosis</a>. <a href="/facts/Interferon-%25CE%25B3/r51CXVph">Interferon-γ</a> (IFN-γ) release assays rely on the fact that T-lymphocytes will release IFN-γ when exposed to specific antigens. These tests are mostly developed for the field of <a href="/facts/Tuberculosis_diagnosis/E7LSvYPL">tuberculosis diagnosis</a>, but in theory, may be used in the diagnosis of other diseases that rely on cell-mediated immunity, e.g. <a href="/facts/Cytomegalovirus/gtxdYP8S">cytomegalovirus</a> and <a href="/facts/Leishmaniasis/L5v8Thy1">leishmaniasis</a> and <a href="/facts/COVID-19/YsUgvsaX">COVID-19</a>. For example, in patients with <a href="/facts/Cutaneous/4havlLzG">cutaneous</a> <a href="/facts/Adverse_drug_reaction/Ea0ktF6J">adverse drug reactions</a>, the challenge of peripheral blood lymphocytes with the drug causing the reaction produced a positive test result for half of the drugs tested. </p><p>There are currently[<i>when?</i>] two IFN-γ release assays available for the diagnosis of tuberculosis: </p> <ul><li><a href="/facts/QuantiFERON-TB_Gold/m6o9QpHd">QuantiFERON-TB Gold</a> (licensed in US, Europe and Japan); and[<i>medical citation needed</i>]</li> <li><a href="/facts/T-SPOT.TB/2BDMWKmY">T-SPOT.TB</a>, a form of <a href="/facts/ELISpot/zo2eKIYV">ELISpot</a>, the variant of <a href="/facts/ELISA/8yvpYDtH">ELISA</a> (licensed in Europe, US, Japan and China).[<i>medical citation needed</i>]</li></ul> <p>The former test quantitates the amount of <a href="/facts/IFN-%25CE%25B3/r51CXVph">IFN-γ</a> produced in response to the <a href="/facts/ESAT-6/JhlAuhFu">ESAT-6</a> and <a href="/facts/CFP-10/dgCdExqF">CFP-10</a> antigens from <i>Mycobacterium tuberculosis</i>, which are distinguishable from those present in <a href="/facts/Bacille_Calmette-Gu%25C3%25A9rin/1hG40pC8">BCG</a> and most other non-tuberculous <a href="/facts/Mycobacteria/mLn82Axu">mycobacteria</a>. The latter test determines the total number of individual <a href="/facts/Effector_T_cells/nhwAYkDj">effector T cells</a> expressing <a href="/facts/IFN-%25CE%25B3/r51CXVph">IFN-γ</a>. </p><p>The indications for the test are still disputed. It has been evaluated for the diagnosis of latent tuberculosis in HIV patients (who frequently have a negative <a href="/facts/Mantoux_test/bkmsTRYs">Mantoux test</a>). </p>