[General Battuta]

Only once, and in one patient, and it was three years ago, but it appears that the patient has not relapsed so WTF, let's talk about it.

Doctors in Berlin believe that transplanting marrow from a CCR-5 negative individual into a patient with HIV cured not only his leukemia but his HIV. Stem cells from the CCR-5 negative dude replaced the patient's immune cells.

HIV uses the CCR-5 receptor as a way into cells, and it's long been known that people who lack the CCR-5 receptor (technically called CCR-5 delta 32 homozygosity, and found mostly in Scandinavia) are largely immune to HIV but otherwise healthy.

The treatment process used for this patient's leukemia, including the marrow transplants that cured his HIV, was incredibly grueling. But future therapies using stem cells from delta 32 homozygous donors might carry a lower risk of killing or debilitating the patient.

More here.

If you want to be cynical about it, the possibility remains that CXCR4-targeting HIV strains will emerge in this patient, or in the population at large if the therapy becomes more widely used. CXCR4 is another receptor often targeted by HIV.

[Nuke]

does this "cure" completely eliminate the virus to the point where it can no longer transmit the virus or does it make the patient a carrier who themselves does not suffer any further ill effects? also it must be noted that bone marrow transplants are usually a pretty brutal ordeal for both doner and recipient and are as expensive as they are painful. it sounds like this cure would be ridiculously expensive in places like africa where aids is a real problem. id really rather see better dispersal of aids medications to such places rather than see super-expensive cure options magically pop up. same kinda thing happens with malaria. we have drugs to help the disease, but distribution to the 3rd world is either lax or non-existant, or worse controlled by warlords as a means to maintain power.

[General Battuta]

The virus is undetectable to any test performed on the patient so far, but that doesn't mean it's not present. HIV is notorious for going to ground in difficult-to-sample organs. If I were this guy I wouldn't be going to any orgies quite yet.

The brutality of marrow transports is indeed noted in the original post.

[achtung]

I remember reading about/using this when I did a little AIDS research paper in freshman year. Surprisingly nobody, not even the professor, knew about it.

[karajorma]

I had wondered in the past why leukaemia treatments that basically consist of wiping out the immune system and then replacing it via transplants didn't work against AIDS.

Okay with the immune system dead there's nothing to scavenge up the HIV virus that isn't in the white blood cells but wouldn't a course of antivirals help there?

[headdie]

I thought the anti-virals for aids were pretty brutal themselves

[Kolgena]

Marrow transplants are difficult and easily lead to complications. It's questionable if you satisfy the Do No Harm vs Beneficence principle here.

[General Battuta]

Marrow transplants are difficult and easily lead to complications. It's questionable if you satisfy the Do No Harm vs Beneficence principle here.

Third to last paragraph, first post!

[Kolgena]

Because stem cell transplants will magically be much safer when you're trying to transplant an entire immune system. Gene therapy holds some promise, but that's a long-shot to get working, and not news in any way.

[General Battuta]

I'm optimistic that future therapies might carry a lower risk.

[Kolgena]

Just advocating for the devil. If any treatment works, I'd be as pleased as anyone.

[Bob-san]

Marrow transplants are difficult and easily lead to complications. It's questionable if you satisfy the Do No Harm vs Beneficence principle here.

Third to last paragraph, first post!

Marrow transplant is not foolproof. At best, this "cure" is only useful to those who already need a marrow transplant, in which case the larger concern is whether or not the primary illness will be treated. Presence or absence of the receptors isn't even a secondary concern. Eventually, HIV/AIDS will help kill you.

[Kolgena]

What?

At least in this case study, the guy's AIDS went into remission after he got new T_H cells that lacked the receptor. After a generation turnover, the resident HIV would have serious issues keeping itself in the body except for the pockets of other tissues it could infect.

[General Battuta]

Marrow transplants are difficult and easily lead to complications. It's questionable if you satisfy the Do No Harm vs Beneficence principle here.

Third to last paragraph, first post!

Marrow transplant is not foolproof. At best, this "cure" is only useful to those who already need a marrow transplant, in which case the larger concern is whether or not the primary illness will be treated. Presence or absence of the receptors isn't even a secondary concern. Eventually, HIV/AIDS will help kill you.

oh baldercocks

Third to last paragraph, first post, why are you restating what was said in the OP?

In fact further tonguelashing for not reading the article: presence or absence of the receptors is a primary concern because with them gone the HIV infection is apparently completely cured. Apparently. If appearances are true, it is gone from his body (but they may not be; HIV is capable of lurking in reservoirs as was, again, already clearly stated in this thread). His leukemia treatment was also successful but far more grueling and costly.

HIV/AIDS can't help kill you if it's gone. If therapies using delta 32 homozygous stem cell transplant can be devised without the impact of marrow transplant, it may provide a less destructive way to cure HIV in patients, if the virus does not develop resistance by switching receptors.

[Kolgena]

It's more complicated then simply sticking the stem cells in a guy's thigh bone and hoping that his AIDS will go away. I see a couple of things that are wrong with this:

http://en.wikipedia.org/wiki/Graft-versus-host_disease: You're taking someone else's immune system and plopping it into your own body. Especially since you're not replacing the entire marrow, you can expect a lot of potential fighting between the immune systems  as they mutually reject each other.

If T_H cells of the host and the transplant decide to co-exist nicely, it'll likely only confer resistance, and not outright elimination of the HIV virus. Sure you won't be dead as quickly from having no immune system, but you'll be a carrier likely in a perpetually weakened state. Also, because you carry the new receptor along with a huge HIV reservoir, you're a walking selection tank to breed out HIV strains that will be able to use the new receptor.

[General Battuta]

All discussed in the article.

Seriously if people don't start reading the OP and the linked article I may blow a gasket. I don't want to spend time answering 'objections' that are already settled in reality.

But here, because I am a ball of rage

You're taking someone else's immune system and plopping it into your own body. Especially since you're not replacing the entire marrow, you can expect a lot of potential fighting between the immune systems  as they mutually reject each other.

See the article. Massive immunosuppression is part of why the marrow transplant was so grueling for the patient. That's how it was handled here. Better methods will be required if this therapy is to be made more accessible.

If TH cells of the host and the transplant decide to co-exist nicely, it'll likely only confer resistance, and not outright elimination of the HIV virus.

Read the thread, see the answer.

but you'll be a carrier likely in a perpetually weakened state. Also, because you carry the new receptor along with a huge HIV reservoir, you're a walking selection tank to breed out HIV strains that will be able to use the new receptor.

There is currently no evidence that this man is a huge HIV reservoir. Please review the posts in this thread, or the article, both of which explicitly state the current information we have on how much HIV remains in this guy's body.

The reason this is exciting is because it does not appear to have fought the disease to a standstill, it appears to have eradicated it. As has been stated more than once now, appearances can be deceiving.

The selection issue was also brought up in the first post.

[Kolgena]

Calm down. You're talking about marrow replacement. I'm talking about stem cell injection.

The point I'm making is that all the problems with marrow replacement don't go away simply by citing stem cells as a solution.

[General Battuta]

There are obviously a vast number of obstacles left to an effective, let alone affordable, cure. But if peripheral source stem cells from individuals without this receptor can be accumulated, that's - maybe - a first step.

In this case, the new immune cells lacking the receptor completely replaced the old ones in the patient's body. That suggests that partial replacement won't be a problem - except that in this case, radiation and chemo were required to wipe out the original immune system. That's messy.

We need to be certain that the virus is totally eradicated before we can figure out exactly how close to a miracle cure this is.

[Kolgena]

Is 100% eradication absolutely necessary? If you can't find the virus in the guy's blood, then it's not actively replicating, ergo, not actively killing any immune cells. Suppression is more than enough to save a guy's life (though transmission of infection remains a distinct possibility). Of course, the suppression this guy got might be temporary, even though it has lasted 3 years. Then again, 3 years isn't much, since normal disease progression can have HIV take 10 years or so before symptoms appear.

[General Battuta]

Yeah, it's the transmission issue. And if it remains in a reservoir in a hard-to-sample organ it could relapse later, especially if the CXCR receptor variant emerged.