Prozone like effect Index: Difference between revisions
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<span style="font-size:90%"> | <span style="font-size:90%">More correctly the "prozone-like" or "postzone" phenomenon* is a very rare, but recognised effect that causes false negative results of tests. | ||
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<span style="font-size:90%">Most often the prozone effect is seen with HRP2 antigens. This effect means that where these is a '''very high parasitaemia''' (causing excess HRP2 antigen to be present) test can appear negative. It is thought that the presence of excess antigen means that the formation of appropriate antibody-antigen complexes is prevented so that the test does not function correctly.</br></br>*'''Note''' the term postzone effect is preferred in this context as prozone refers to excess antibody, while postzone refers to excess antigen as in this case.</span> | <span style="font-size:90%">Most often the prozone-like effect is seen with HRP2 antigens. This effect means that where these is a '''very high parasitaemia''' (causing excess HRP2 antigen to be present) test can appear negative. It is thought that the presence of excess antigen means that the formation of appropriate antibody-antigen complexes is prevented so that the test does not function correctly.</br></br>*'''Note''' the term postzone effect is preferred in this context as prozone refers to excess antibody, while postzone refers to excess antigen as in this case.</span> | ||
Revision as of 10:20, 26 November 2024
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| The prozone-like (postzone) phenomenon
Most often the prozone-like effect is seen with HRP2 antigens. This effect means that where these is a very high parasitaemia (causing excess HRP2 antigen to be present) test can appear negative. It is thought that the presence of excess antigen means that the formation of appropriate antibody-antigen complexes is prevented so that the test does not function correctly. |