[Question #5474] HIV-1 group P test

22 months ago
Dear Doctor H:               
                   Regarding HIV-1 group P detection, can we detect HIV-1 group P with the fourth generation detection method after 3 months? Current nucleic acid testing cannot detect the viral load of HIV-1 group P. Do you agree?               
                    I read the relevant literature.《A new human immunodeficiency virus derived from gorillas》Mentioned in the text:Since 2001, a French network of reference laboratories has been monitoring HIV genetic diversity. Infection with an unusual variantis suspected when RNA viral load assays or molecular tests are negative in an individual with acquired immunodeficiency naive of antiretroviral therapy. As part of these surveillance activities, we analyzed serial samples from a 62-year-old woman (subject number RBF168) who was found to be HIV seropositive in 2004, shortly after moving to Paris from Cameroon (Supplementary Methods).Several HIV-1 screening tests were all reactive, and western blottingwith HIV-1 group M proteins showed weak reactivity against theenvelope glycoprotein 120 and no reactivity against Gag p18 protein(Supplementary Methods and Supplementary Fig. 1). She currently has no signs of AIDS, remains untreated and has a stable CD4+cell count of about 300 cells per m m3(Supplementary Fig. 2). Her viral load has been consistently high since diagnosis (4.4 to 5.3 log copies per ml) in nonspecific group M and O PCR commercial assays (LCxHIV RNA Quantitative and RealTime HIV1, Abbott) and in anin-house real-time RT-PCR assay(Supplementary Fig. 2). The virus replicates in cultured human donor peripheral blood mononuclear cells and is easily isolated from both the subject’s plasma and periph-eral blood mononuclear cells (Supplementary Methods). Her viralload cannot, however, be quantified with a group M–specific commer-cial assay (Amplicor Monitor v1.5, Roche) or with an academic assay(Generic HIV charge virale, Biocentric8)(Supplementary Fig. 2). Articles website links:
https://www.researchgate.net/publication/26711300_A_new_human_immunodeficiency_virus_derived_from_gorillas
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
22 months ago
Welcome to the forum and thanks for your question.  However, I don't think I can help as much as you would like.

it is apparent that you have learned more about group P HIV infection than I know. I am unfamiliar with the research report you cite and have neither the time nor interest to get into it in detail. I do know that the current HIV tests do not miss any HIV infections in the United States. For example, standard testing of blood and organ transplant donors, generally with both PCR/RNA testing and the currently marketed antigen-antibody (4th generation, duo, combo) tests has 100% prevented new blood- or transplant-borne HIV infections, with very rare exceptions explained by very early infections (typically within a few days of the donor becoming infected), and not because of any missed HIV types that might not be detected by current tests (HIV2, HIV1 group P, etc).

If you have had an exposure you are concerned about and you have had negative PCR testing after ~2 weeks and and/or a standard AgAb tests 6 weeks or more after exposure, you can safely conclude you do not have HIV.

This reply also responds to your follow-up question, which did not require a new question and fee. That question has been deleted, and I will contact the administrator and ask them to reimburse your credit card for the extra amount.

I hope these comments are at least slightly helpful. Best wishes

HHH, MD
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22 months ago
Dear H 
          IN theory the antibody tests may miss some some HIV-1 subgroups?Why?
22 months ago
Dear doctor h
Structure of the antibodies are very similar regardless of the group or strain, hence mutant strains also generate positive/equivocal results rather than negative. That's why PCR tests are not diagnostic but antibody tests are?
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
22 months ago
Sorry, I don't really know. This forum is not a venue for debate or discussion of sophisticated science about HIV testing or any other topic. However, it is not true that "PCR tests are not diagnostic but antibody tests are." Both tests have important and often definitive roles in diagnosing HIV infections.

That concludes this thread. Thanks for your interest.
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