They couldn't do it at all until they had really good HIV-suppressing drugs. You won't do a transplant into somebody with an active HIV infection.

They still won't do it if they can avoid it. This an extreme measure, killing off the entire immune system and replacing it. They still need to find a donor who is sufficiently compatible, and then has the right set of genes.

So it just took time for all of the pieces to fall into place.

Use this to treat diabetes type one, do a pancreas transplant and replace the immune system so it does not reject the transplant.

Usually, just the transplant part is sufficient. https://connect.mayoclinic.org/blog/podcasts/newsfeed-post/h...

It's mentioned in the comments of the article, but "just the transplant" is not really enough. You still need heavy immune suppressants, which is rarely worth the side effects.

That would be fantastic, but there are enormous tradeoffs. This is massive, massive surgery that comes incredibly close to killing the patient.

They are unlikely to do it if the disease can be controlled with an insulin pump, which is far less invasive. Insulin pumps are far from perfect solutions. (Somebody close to me has one and I can observe what a massive pain in the ass it is, among other places.) But surgery like this is going to have to come a long way before it's routine enough to replace a therapy that is aggravating but sufficient.

I'm guessing that HIV positive patients who also develop a type of cancer that can receive bone marrow transplants as treatment are rare. Bone marrow matches are extremely rare. Add to that: bone marrow matches with the particular mutation (CCR5-delta 32) can only compound that rarity. All this adds up to poor odds.

Indeed. But rapid advances in genetic therapies mean it may someday be possible to 'upgrade' a patient's existing marrow in-place, with just the necessary new genes.