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Prozone effect: Difference between revisions

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|colspan="1" style = "font-size:110%; color:blasck; background: FFFAFA"|<span style="color:navy>'''The prozone-like phenomenon'''</span>
|colspan="1" style = "font-size:110%; color:blasck; background: FFFAFA"|<span style="color:navy>'''The prozone-like (postzone) phenomenon'''</span>




The prozone-like phenomenon (perhaps better termed the postzone effect in this context) is a very rare, but recognised effect that causes false negative results of tests.  
The prozone-like or "postzone" phenomenon (the term postzone effect is preferred in this context as prozone refers to excess antibody, while postzone refers to excess antigen) is a very rare, but recognised effect that causes false negative results of tests.  


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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.
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.

Revision as of 10:27, 9 October 2024


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The prozone-like (postzone) phenomenon


The prozone-like or "postzone" phenomenon (the term postzone effect is preferred in this context as prozone refers to excess antibody, while postzone refers to excess antigen) is a very rare, but recognised effect that causes false negative results of tests.


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.