[HN Gopher] 5th person confirmed to be cured of HIV
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5th person confirmed to be cured of HIV
Author : cwwc
Score : 124 points
Date : 2023-02-20 20:40 UTC (2 hours ago)
(HTM) web link (abcnews.go.com)
(TXT) w3m dump (abcnews.go.com)
| starik36 wrote:
| We need Pedro Pascal to take him to the other side of the
| country.
| biosboiii wrote:
| _All four of these patients had undergone stem cell transplants
| for their blood cancer treatment. Their donors also had the same
| HIV-resistant mutation that deletes a protein called CCR5, which
| HIV normally uses to enter the cell. Only 1% of the total
| population carries this genetic mutation that makes them
| resistant to HIV._
|
| The article is horribly wrong about CCR5 being the only pathway
| of the HI Virus to infect your cells and ultimately cause AIDS.
|
| _A problem of this approach is that, while CCR5 is the major co-
| receptor by which HIV infects cells, it is not the only such co-
| receptor. It is possible that under selective pressure HIV will
| evolve to use another co-receptor._ [1]
|
| Why this treatment still worked is because:
|
| _However, examination of viral resistance to AD101, molecular
| antagonist of CCR5, indicated that resistant viruses did not
| switch to another co-receptor (CXCR4), but persisted in using
| CCR5: they either bound to alternative domains of CCR5 or to the
| receptor at a higher affinity. However, because there is still
| another co-receptor available, it is probable that lacking the
| CCR5 gene does not make one immune to the virus; it would simply
| be more challenging for the individual to contract it._ [1]
|
| So a mixture of anti-retroviral treatments, which suppress the
| HIV replication to a point of not showing up in PCR tests anymore
| (while taking the medication), and (partially?) inhibiting the
| remaining viruses from infecting cells via the CCR5 pathway,
| further limiting their replication, caused these patients to be
| cured.
|
| I don't know if the replication slowed down so much that their
| body was able to kick HIV out once and for all, or blocked it
| outright because the already reduced number of viruses simply
| could not beat the odds of infecting via a alternative pathway.
| Kudos to the researchers!
|
| Why is this important: The CRISPR babies[2] had this exact gene
| removed, and everybody claimed that he cured them from ever
| getting HIV, even though it's simply not true.
|
| Note that there are also drugs which disable CCR5, without gene
| modification (Selzentry).
|
| [1] https://en.wikipedia.org/wiki/CCR5 [2]
| https://en.wikipedia.org/wiki/He_Jiankui_affair
| Vecr wrote:
| I'm actually somewhat skeptical that all (or even any) of the 5
| people has actually been cured of HIV. Prevented from getting
| AIDS before they die without requiring any further treatment,
| possibly, but I'm having trouble figuring out the logistics of
| every single viable copy of the virus, both as RNA and proviral
| DNA, has actually been eradicated. I think it's quite likely
| that at least one of these 5 people have (or had, being dead is
| not great) something in their body that could be transfected
| into another person's cells and cause an active HIV infection.
| This could be DNA (would have to be cut out and transfected
| into a cell, or the cell would have to be injected into the
| other person), or virions that escaped detection.
| asveikau wrote:
| I don't know much about this, but I read that some primates
| have endemic SIV and don't get sick, whereas some other
| species of primate will die of AIDS after exposure to SIV.
|
| For example, Wikipedia on SIV says that ~90% of female
| African green monkeys (vervets) have SIV, and don't get AIDS.
|
| From there one imagines that a primate species on first
| exposure to the virus has it as a deadly disease, but
| sometimes they evolve a resistance to getting sick from it,
| without eradicating the virus.
| nathanvanfleet wrote:
| k thanks, so I guess you've studied this for as long as it
| took to write 129 words on the subject. I am going to have to
| be way more interested in the actual people who are studying
| and experimenting with this at this point, I can't allocate
| any interest at all in your 129 word paper on the subject.
| elil17 wrote:
| >> I think it's quite likely that at least one of these 5
| people have... something in their body that could be
| transfected into another person's cells and cause an active
| HIV infection.
|
| No, they definitely don't. It's well known[1] that people
| without detectable levels of HIV in their blood cannot
| transmit HIV to other people. That is true for people who are
| simply receiving normal treatments (see:
| https://www.nih.gov/news-events/news-releases/science-
| clear-...). It is certainly also true for these transplant
| recipients.
|
| Edit: [1]: Specifically, researchers have never observed
| transmission from someone with undetectable viral load,
| despite many large studies searching for such an event
| nostromo wrote:
| What you've said is true, but I'd add that there are
| worrying number of HIV+ men that have stopped disclosing
| their status to sexual partners because they've heard that
| "undetectable = untransmissible." While that does seem to
| be true, there are a number of problems with this:
|
| 1. Not everyone takes their medications exactly as
| prescribed.
|
| 2. Lots of folks on antiretroviral therapy are not
| undetectable, or may move between undetectable and
| detectable over time.
|
| It's important that people still disclose their status to
| sex partners.
| umanwizard wrote:
| > there are worrying number of HIV+ men that have stopped
| disclosing their status to sexual partners because
| they've heard that "undetectable = untransmissible."
|
| I thought that was the entire point of the "undetectable
| = untransmissible" campaign -- freeing people from
| worrying about passing it to others and having to live
| with a scarlet letter, which is an incentive to get
| treated
|
| > It's important that people still disclose their status
|
| Why?
| NovemberWhiskey wrote:
| Apologies, I know nothing about this at all, but why is it
| more surprising for HIV than other viral diseases that do
| have successful cures (like hepatitis C)?
| notahacker wrote:
| In simple terms, rather than always using a cell it takes
| over to make as many copies of itself as possible which
| then circulate and get dealt with by the (possibly boosted)
| immune system, HIV can hide itself in human DNA and let the
| normal human cell division process create a reservoir of
| apparently normal human cells which can produce copies of
| the virus in future
| bboygravity wrote:
| TLDR: HIV edits your genome to add itself into it.
| eckesicle wrote:
| It's been a few years now but I used to work on research on
| this particular alternative receptor.
|
| To handwave and simplify a bit CCR5 is the dominant pathway for
| the virus to spread in a healthy patient. HIV tends to mutate
| in patients from attaching to CCR5 (called phenotype R5) to
| CXCR4 (called X4) once the immune system is weaker. Patients
| with the X4 are not as infectious as a healthy immune system
| can fend it off.
|
| So CCR5 is more or less the only pathway for the virus to
| infect a healthy host, as far as I can remember.
| [deleted]
| moffkalast wrote:
| 38.4 million more to go.
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