[redsniper]

ITT: people who would've looked at the Wright flyer and said "bah, but it can't cross the ocean or go over mountains. Why get excited?"

[Kolgena]

I'm not sure that's a non-negligible possibility. If there's no virus in the blood (well, then again, "no virus" just means too few for our techniques to pick up), it's pretty certain that no tissues have actively replicating viruses in them. Exception might be HIV in the CNS that can't cross the blood/brain barrier, but if those can't get out, they're not transmissible unless you start leaking cerebrospinal fluid etc. into people's cuts.

Without active replication, there's no selection. Without selection, it'd take pretty long for a new strain to emerge.

[General Battuta]

I'm not sure that's a non-negligible possibility. If there's no virus in the blood (well, then again, "no virus" just means too few for our techniques to pick up), it's pretty certain that no tissues have actively replicating viruses in them. Exception might be HIV in the CNS that can't cross the blood/brain barrier, but if those can't get out, they're not transmissible unless you start leaking cerebrospinal fluid etc. into people's cuts.

Without active replication, there's no selection. Without selection, it'd take pretty long for a new strain to emerge.

I want to agree, since it'd be a dream scenario.

They seem to be leaning that way. I hope they're right.

Nevertheless HIV remained undetectable by both viral load testing (RNA) and tests for viral DNA within cells, and HIV antibody levels declined to the point that the patient has no antibody reactivity to HIV core antibodies, and only very low levels of antibodies to the HIV envelope proteins.

Seventeen months after the transplant the patient developed a neurological condition, which required a brain biopsy and lumbar puncture to sample the cerebrospinal fluid for diagnostic purposes. HIV was also undetectable in the brain and the CSF.

An additional indication that HIV is not present lies in the fact that the patient’s CD4 cells are vulnerable to infection with virus that targets the CXCR4 receptor. If any virus with this preference was still present, the researchers argue, it would be able to swiftly infect the large population of memory CD4 cells that has emerged.

There were CXCR4 viruses present before the marrow transplant, and I think they're the biggest risk factor, but

Before the treatment though the patient had low levels of the CXCR4 virus but after the treatment this type of HIV could not be detected either which Hütter called "very surprising".

[Titan]

Aren't umbilical cords chock-full of stem cells?

[General Battuta]

That is one possible method for gathering the necessary stemcells, yeah.

[headdie]

Aren't umbilical cords chock-full of stem cells?

The issue with that is umbilical cord means babies which is a tetchy subject at best

[Kolgena]

The current main source of stem cells is discarded embryos, which is a fair bit worse than umbilical cords.

Of course, there's research to tease differentiated cells back into stem cells, but so far those are limited by various problems and imperfections.

[General Battuta]

Aren't umbilical cords chock-full of stem cells?

The issue with that is umbilical cord means babies which is a tetchy subject at best

Nah, umbilical cords are fine - there's not much controversy that I know of about harvesting them, since they're usually just discarded anyway.

[karajorma]

This guy had AIDS AND Leukaemia? Poor unlucky bastard. I mean in the end it seems to have turned out well for him but breaking the news to him about the second one of those must have been pretty uncomfortable.

Seventeen months after the transplant the patient developed a neurological condition, which required a brain biopsy and lumbar puncture to sample the cerebrospinal fluid for diagnostic purposes.

The neurological problem led to temporary blindness and memory problems. Brown is still undergoing physiotherapy to help restore his coordination and gait, as well as speech therapy.

Seriously unlucky. They don't say if the condition was related to either of the diseases. Cause if it was a third, unrelated condition.....

[General Battuta]

His misfortune is a boon to the scientific community, though - that brain biopsy has to be valuable for figuring out if there was a latent HIV reservoir there. (I believe that does happen.)

[Bobboau]

I don't know, the guy was cured of both of them, that screams lucky to me.

[karajorma]

I know, but at the time he got the second diagnosis.....

[MP-Ryan]

I knew about this.  I actually asked a professor about the theory concerning total immune replacement with altered chemokine receptors back in 2006.  His answer, and I quote:  With the current antivirals available, the risks of replacing an immune system to cure the virus far outweigh the potential cures.

It is definitely interesting that it actually worked in practice (to be honest, I'm a little surprised that the doctors in question are surprised after having found the chemokine mutation), but it's not entirely unexpected and definitely not a practical cure.  For one, he shouldn't actually be cured of the virus itself - altering the chemokine prevents HIV from infiltrating T cells, but it doesn't contribute to efficacy in clearing viral load from the bloodstream.  It DOES allow the immune system to catch up to the virus though, which in this case may have (this is surprising) allowed the immune system to actually clear the virus.  Important distinction:  this treatment didn't cure his HIV infection - it slowed the virus enough to allow his immune system to do it (apparently).  However, considering the rate at which HIV mutates (dozens to hundreds of viral variants can be found in single patients after years of infection), it's a pretty safe bet that his HIV infection will probably eventually return - though with hefty doses of antiretrovirals and a good bit of luck, he may not relapse.  Only time will tell.  Part of the reason that HIV is such a nasty virus is because it is so good at evading the immune system and the antibody-mediated immune response in particular.

Anyway, I wouldn't jump up and down on this one too much.  This is a case of really good luck combined with excellent medical care.  Immune replacement therapies are so risky that they aren't an option for the majority of HIV infections, especially considering how good today's antiretrovirals are.

One option, as someone suggested, is to develop stem cell therapies whereby the immune system is not replaced but gains the ability to produce CCR5- T cells... in which case, the patient would still be infected with HIV and able to transmit it, but would not progress to AIDS and therefore have higher survivability.  But that's a long, long way off... and there are other chemokine receptors that permit the virus to gain entry.

[General Battuta]

Yeah, but the weird thing is that the variants of the virus which go for those other receptors were present before the therapy but also died. What up with that?

[MP-Ryan]

Yeah, but the weird thing is that the variants of the virus which go for those other receptors were present before the therapy but also died. What up with that?

Maybe chemokine receptors use transcription/RNA splicing to create their various iterations.  I wonder if the researchers ran an amino acid sequence of all this patients' chemokine receptors?

The other option is that if the alternate chemokine receptor transport mechanism isn't as efficient, the larger pool of available T cells essentially caught up and cleared those HIV variants too.

I would imagine that they're in the process of sequencing the donor genome entirely.  I certainly would be, at this point.