This is a follow-up to my post on the man that was cured of HIV with a bone marrow transplant. A presentation made at a scientific meeting in early June provides data that indicates he still harbours some HIV, which brings into question what constitutes “cured” when you’re talking about HIV? This patient stopped taking antiretroviral drugs after he had the transplant, the virus never returned and his doctors pronounced him cured from HIV.
Steven Yuki (UCSF), who works in Joseph Wong’s lab made the presentation at the meeting. They found some signals of HIV in the man’s body, but are unsure if these are real or from contamination. Yuki used a technique called polymerase chain reaction (PCR) to look for any signs of HIV. PCR allows you to amplify small quantities of (specified sequences) nucleic acid to determine if what you are looking for is present. When they performed PCR on the man’s cells they detected bits of viral nucleic acid, but a collaborator in a different lab didn’t detect any. This is highly suggestive that contamination of Yuki’s sample occurred, but the possibility can’t be ruled out that the man still harbours some HIV. Even more puzzling, another collaborator found signs of the virus, but it was unable to make copies of itself, suggesting it is harmless or defective genetic pieces of HIV. What makes this even more complicated is that the bits of virus don’t match each other, or the virus that he was infected with before the transplant. This provides stronger evidence that contamination of the samples may have occurred. Alain Lafeuillade (General Hospital of Toulon, France) wasn’t involved with the new study, but has issued a press release and a blog post with his interpretation of the results. He questions whether the man was reinfected with HIV and is still infectious to others. This could be possible because the virus detected doesn’t match the original virus the man had.
This new information calls into question what defines being “cured” when you’re discussing HIV. If you can’t detect the virus using p24 assays (the most common detection method), does that mean you’re cured? What if the p24 assay is negative but HIV nucleic acid is present – are you considered infected? Despite the question about whether he has been cured or not, the man has been off antiretrovirals for 5 years and is healthy. I think he, and others with HIV, would consider that cured . . . no matter what scientists decide.
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