Hacker News Reader

Comment by inasio | Hacker News Reader

The first two cured patients (unsure about the third) were also cured by a similar bone marrow transplant from a resistant donor (and I think leukemia was also present?). This is good news, as validation of the other cases, but it still remains an infeasible path for the vast majority of HIV positive people.

View on HN

True. But maybe additional confirmation that this pathway really works will help spur research into a way to replicate the same effect, without requiring the full bone marrow transplant process?

What makes HIV hard to eliminate is that it persists in bone marrow. What's happening in these transplants, in cancer patients who also have HIV, is that the patient's original bone marrow (having become cancerous) is killed off and completely replaced, taking the HIV with it. And killing off the original bone marrow is the nastiest part of the procedure by far (source: my uncle went through it) -- but that's what gets rid of the HIV. Anything that replicates that effect would be an alternative transplant process, not an alternative to one.

> What's happening in these transplants, in cancer patients who also have HIV, is that the patient's original bone marrow (having become cancerous) is killed off and completely replaced, taking the HIV with it.

That's not accurate. If that were the case, then ANY bone marrow transplant could potentially cure an HIV patient. What's happening is that bone marrow is what generates white blood cells, and the donor in this case was naturally resistant to HIV due to the CCR5 delta 32 mutation. This results in white blood cells that HIV can no longer easily enter.

So what's happening is ALL of the patient's white blood cells are being replaced (rather, generated by this new donor marrow) with ones that are resistant to HIV.

What stops us from inducing a CCR5 delta 32 mutation in hiv infected people?

What process do we have to reliably mutate every single cell of certain types in bone marrow, with only a desired mutation and no other?

DNA Vaccines?

We don't have a process to do what is described.

a modified HIV vector?

Even if a small amount of unmutated cells remain that still means that the person is cured of HIV right? Though they may still be infectious

Thanks for the correction.

> But maybe additional confirmation that this pathway really works will help spur research into a way to replicate the same effect, without requiring the full bone marrow transplant process?

Doubtful. It's been known for a long time that the CCR5-delta 32 mutation conveys HIV resistance because it results in a different CCR5 coreceptor which HIV uses to enter white blood cells (this is the whole reason the bone marrow donor was selected in the first place).

Thus, the bone marrow transplant process works because now ALL of this patient's cells have that different, resistant CCR5 coreceptor. Hard to imagine a way to replicate this process without some method that results in all new white blood cells being generated like this.

Fair enough.

Genetic modification delivered via mRNA? There are some biohackers that do that sort of stuff, so it would imply at least some feasibility

Reply on news.ycombinator.com