Patient with syphilis (under treatment) tests positive for HIV by two ELISA's taken on two consecutive days (positive on repeat testing a couple of months later), but no detectable viremia and high CD4 count. Is it possible for the HIV test to be falsely positive by cross-reactivity with anti-syphilis antibodies? This is a recent case, not a historic one, with tests currently used for screening for HIV in the hospital.
The fact that the person has one STD always increases the risk for another STD. Early in HIV infection some people control virema. That may be an explanation for lack of detectable virema even if using modern molecular techniques which are quite sensitive. On the other hand, HIV is an enveloped virus and as such brings a lot of cellular antigens with it. If you are using an ELISA with whole virus as its antigen then the cellular antigens will be in the plate. It is possible to have anti-self antibodies that cause a false positive in current HIV tests. This is rare, but possible. Have you performed a Western Blot to get an idea which proteins the person has antibody against. Sometimes this will help.
This case might be a false positive result although persistently positive results are quite rare. A fourth-generation ELISA (testing for both HIV antibodies and p24 antigen) would be more reliable and useful than a test only looking for antibodies; however, it is interesting that viremia was not detectable. Which kind of ELISA did you use? Did you look for a different HIV test or at least try an ELISA from a different manufacturer? Any update since last week?
Dear you should look for a high sensitive and specific ELISA kit.
- Badges
- Science method
- Similar topics
- Medicine
- Immunology
- Immunology Techniques
- Immunoassay
- ELISA