This question crossed my mind recently. The medication that I take, Viread, is against both HBV and HIV. If it reduced the number of hepatitis B viruses to an undetectable level, does it mean that it’ll reduce number of HIV copies to the point that a fourth generation test will show a false negative result?
You cannot take Viread for treating, nor preventing HIV. Taking it alone is very likely lead to HIV resistance. If you are at risk of HIV infection, take Truvada (TDF/FTC) or Descovy (TAF/FTC) as PrEP to prevent HIV infection. If you have HIV/HBV coinfection, in addition to Viread, other HIV medication like Integrase or entry inhibitors are needed.
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Hi @Arb,
You are correct that Viread also works against HIV, so it could suppress HIV levels below the limit of detection by PCR-based tests in some cases. It would have lesser effects on the protein-based assays that measure HIV proteins, and it would have no effect on detection of anti-HIV antibodies.
@Jacki is also correct that Viread (active ingredient = tenofovir in the form of TDF) cannot be taken alone for HIV. HIV mutates at a truly amazing speed, and using one drug alone against it can lead to full resistance within weeks to a couple of months. Therefore, its impact on HIV detection would likely be transient.
Tenofovir resistance by HBV on the other hand is so exceptionally rare that it is considered clinically irrelevant. We are not fully sure why HBV cannot develop resistance in people to tenofovir as resistance can be generated in lab studies. Part of the reason is that the HBV surface glycoproteins (HBsAgs) are encoded by exactly the same DNA nucleotides as encode the HBV polymerase active site where DNA is synthesized. That reduces the ability of HBV to develop resistance, but it is not the only reason. There must be some other fitness cost to HBV that keeps it from surviving in the body when it has mutations that generate resistance to tenofovir. Its a scientific mystery, but a great thing for people living with HBV!
John.
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