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Avatar universal

HIV testing

i had an exposure six years ago and only now i was convinced to get tested, after waiting 4 days it came back negative, i asked the doc what type of test they did and he told me P21 P24 what is this? can i trust the result and forget about it. thanks to you all
3 Responses
239123 tn?1267651214
MEDICAL PROFESSIONAL
We discussed your HIV risks on this forum back in 2008, when I informed you that your exposures were low risk.

Probably you misunderstood what your doctor said about p21, and my guess is you had a "duo" test (also called a combo test), which measures both HIV antibody and p24 antigen.  Your negative result is 100% reliable.  You don't have HIV.  It's too bad you waited so long to be tested; you have been through 6 years of unnecessary anxiety about it.  In any case, you can now put your HIV fears to rest.

Good luck--   HHH, MD
Avatar universal
thanks dr, i have read that P24 antigen test usualy detected only on the early stage of infection and can not be detected lator on. is that true?
239123 tn?1267651214
MEDICAL PROFESSIONAL
Yes, that is true.  p24 goes away when antibody develops; in fact, it is the antibody that clears p24 antigen from the blood.  Therefore, when p24 clears, if someone is infected with HIV, antibody has to be present. if both antibody and p24 are negative, it is 100% proof that someone didn't catch HIV.  

That will be all for this thread.  Move on.  I won't have any further comments or advice.
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