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Is it HIV-2 or false positive?

  • 1.  Is it HIV-2 or false positive?

    Posted 05-25-2022 10:59
    Hi! I have 64 yo cis M w/ Parkinson's, HTN, leukopenia thought to be d/t ethnicity (already saw Hem/onc in 2021), and h/o HBV infx resolved. Recent ED visit for hip fracture. He is originally from West Africa, moved here about 20 years ago. H/o blood transfusion 1980 but identifies as Muslim and only having had 1 lifetime sexual cis F partner. No h/o IVDU. Wife is HIV negative. HIV-1 VL undetectable. HIV-2 VL undetectable. CD4 is 155, %33. Repeat HIV supplemental ~3 weeks later is still positive. Do I call this false positive and work on discovering what's causing the cross reactivity? Any ideas on further work up? Do I send him back to Heme? Goes back and forth frequently to West Africa to visit family.

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    Michelle Moore
    Chicago IL
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  • 2.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 15:14
    Just to be clear, you're saying the HIV-2 antibody is positive?
    Which HIV-2 VL assay did you use? So I'm more so curious for my future knowledge if this comes up since I know you can't used the HIV-1 assays.

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    Katy Garrett
    Lexington KY
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  • 3.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 16:08

    Was it an HIV 1/2 differentiation assay that he has been testing positive on?

    How does the CBC differential look? 




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    Francis Matuszak
    Miami Lakes FL
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  • 4.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 17:59
    Yeah, it is the differential that's been positive and the preliminary p24 antigen, too. Mild leukopenia but that's it.





  • 5.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 18:02
    Sorry to be more clear, the differentiation assay is positive for both HIV-1 and HIV-2.

    The HIV-1 viral load RNA is undetectable. And the HIV-2 viral load RNA is undetectable (this one I had to send to away to Washington to be completed).





  • 6.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 18:56
    Hi Michelle,

    If his 4th gen test is repeatedly +, is the confirmatory antibody test for HIV 1 positive as well?   If so, and the HIV 1 RNA and HIV 2 RNA tests are repeatedly negative, then he would qualify as as an elite controller. Sometimes, in cases like this, we run a proviral DNA test (DNA Archive),and if it amplifies, that would prove actual HIV infection. If the confirmatory antibody test is negative, then the positive 4th gen result would be a false positive.  Regardless of his HIV status, he appears to have no active HIV replication, and his suppressed CD4 cell count would be due to some other cause. Interesting case!  Hope this is helpful.

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    Adam Zweig
    AIDS Healthcare Foundation
    San Diego CA
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  • 7.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:24
    Oops.  Sorry.  I did not see that his HIV 1 and HIV 2 confirmatory antibodies were positive.    Sounds to me like he has both HIV 1 and HIV 2 infection, and has immunologic control of viral replication.    So, his low CD4 count is likely due to another process.

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    Adam Zweig
    AIDS Healthcare Foundation
    San Diego CA
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  • 8.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:28
    Some might recommend starting ARV therapy, especially given his low CD4 count., even if he has vial suppression currently.    You would want to avoid an NNRTI regimen since it appears that he has HIV  2 infection. Once again, I apologize for all of the separate messages.   Writing these in the middle of seeing patients!

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    Adam Zweig
    AIDS Healthcare Foundation
    San Diego CA
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  • 9.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:39
    Hi, thanks for all the responses.

    His HIV 4th gen is repeatedly reactive, and BOTH the HIV-1 and HIV-2 antibodies in the differential are positive. The quantitative HIV-1 Viral load is undetectable and the quantitative HIV-2 is undetectable.

    Is it possible he is an elite controller for both HIV-1 and HIV-2 or are we seeing cross reactivity?

    Finally, which lab can I send HIV-2 DNA test to? Washington or NY health department like the HIV-2 rna viral load test?







  • 10.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:48
    Where are you located?  Your local lab did HIV-2 VL?  Maybe you can call them and see what they say about the HIV2 VL that they do?  I would imagine that you could send it to Wadsworth.  Why dont you call the hotline and find out if your State Lab does HIV-2 VL?

    If you want to call Wadsworth - feel free to send me an email to my work and I can email you all the wadsworth contact info and you can call them.  Before I call the pt an Elite controller - I would want to ensure that the HIV2 VL bdna is tested correctly.

    Best!

    my work email if you want:
    sara.back@nychhc.org

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    Sara Back
    North Central Bronx Hospital
    New York NY
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  • 11.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:29
    Hi - My question is what lab did your HIV-2 VL?  Here in NY - we have to send our specimens to Wadsworth Laboratory.  They are the ones that I know of in NYS that do a HIV-2 VL.  I would ensure that you are sending the HIV-2 specimen to the correct lab.  I hope this helps.

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    Sara Back
    North Central Bronx Hospital
    New York NY
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  • 12.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:44
    Hi, yes, I sent it to Wadsworth lab. 





  • 13.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 19:50
    So there you have it - different and probably a false positive.

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    Sara Back
    North Central Bronx Hospital
    New York NY
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  • 14.  RE: Is it HIV-2 or false positive?

    Posted 05-25-2022 21:19
    HIV-2 is endemic to l only to western and ventral Africa and is much harder to transmit than HIV-1. It's even theorized it might eradicate itself over time because it's harder to transmit. Given the higher rates of false positive differentiation assay for HIV 2 it's likely a false positive in the context of someone without travel to those regions or without a clear means of transmission. But given that your patient was spent extensive time there and history of HBV which follows similar transmission patterns I would err on the side of caution and consider him to be a true positive and perhaps an elite controller. It is interesting that there is so much discordance between the absolute and percentage of CD4. I would wonder if this has an alternative explanation.

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    Ben Sokoloff, DO
    Cascade AIDS Project
    Portland, OR
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  • 15.  RE: Is it HIV-2 or false positive?

    Posted 05-26-2022 18:08
    Ben,

    It looks like patient is from West Africa, and the mode of transmission was postulated to be a tainted blood transfusion in the early 80s.  So, the + HIV 2 confirmatory antibody test could certainly be a true +.  Perhaps it would help to repeat the confirmatory antibodies, as well as the HIV 1 RNA and HIV 2 RNA assays.

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    Adam Zweig
    AIDS Healthcare Foundation
    San Diego CA
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  • 16.  RE: Is it HIV-2 or false positive?

    Posted 05-27-2022 18:02
    I think you have more evidence against HIV1/2 than in favor.

    1. By history, he has a single possible transmission event via the transfusion 40+ years ago.
    2. No evidence of viral replication on either HIV 1/2 viral load.
    3. Despite low absolute CD4 count, he has leukopenia and his CD4% is normal suggesting that he doesn't have selective depletion of the CD4s. 

    And even assuming he is positive on antibody, he has no viral load, so he is not transmissible; so we don't have to tackle the question of starting ARVs or not.

    I would say a work-up should focus heavily on his hematologic/immunologic life. Does he have a history of frequent infections? Does his CBC have disruptions in multiple cell lineages or just lymphocytes? How has the blood cell count looked over time? Is it dropping or has it been stable for his whole life? Is he taking any meds associated with leukopenia?

    Physical exam focused on the lymphoid tissues, looking for hepatosplenomegaly, inflammation of the joints, rash, thrush.

    For labs, I agree with the HIV 1 & 2 proviral DNA for peace of mind. I would also check a peripheral blood smear. ESR. CRP. And probably flow cytometry.

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    Francis Matuszak
    Miami Lakes FL
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