Man appears free of HIV after stem cell transplant

[Sebastian Doyle]

A 42-year-old HIV patient with leukemia appears to have no detectable HIV in his blood and no symptoms after a stem cell transplant from a donor carrying a gene mutation that confers natural resistance to the virus that causes AIDS, according to a report published Wednesday in the New England Journal of Medicine.

"The patient is fine," said Dr. Gero Hutter of Charite Universitatsmedizin Berlin in Germany. "Today, two years after his transplantation, he is still without any signs of HIV disease and without antiretroviral medication."

The case was first reported in November, and the new report is the first official publication of the case in a medical journal. Hutter and a team of medical professionals performed the stem cell transplant on the patient, an American living in Germany, to treat the man's leukemia, not the HIV itself.

However, the team deliberately chose a compatible donor who has a naturally occurring gene mutation that confers resistance to HIV. The mutation cripples a receptor known as CCR5, which is normally found on the surface of T cells, the type of immune system cells attacked by HIV.

The mutation is known as CCR5 delta32 and is found in 1 percent to 3 percent of white populations of European descent.

HIV uses the CCR5 as a co-receptor (in addition to CD4 receptors) to latch on to and ultimately destroy immune system cells. Since the virus can't gain a foothold on cells that lack CCR5, people who have the mutation have natural protection. (There are other, less common HIV strains that use different co-receptors.)

People who inherit one copy of CCR5 delta32 take longer to get sick or develop AIDS if infected with HIV. People with two copies (one from each parent) may not become infected at all. The stem cell donor had two copies.

<snip>

http://edition.cnn.com/2009/HEALTH/02/11/health.hiv.stemcell/index.html?eref=rss_mostpopular

And you thought the right wingers were opposed to stem cell research before??

[originalpckelly]

1. I assume this not embryonic research...

that's what was in question, because it presents lots of help in other areas.

I wonder if it has to be stem cells, perhaps they can just do blood transfusions from people with two copies of the special gene?

[muriel_volestrangler]

5. I have no medical or immunological training, but I think

that you'd need the stem cell (bone marrow) transplant to have a continuing source of the resistant T cells - unless the transfusion could wipe out absolutely all of the HIV in one go. Even in this case, they said:

Levy also said it's unlikely that the transplant truly cured the patient in this study. HIV can infect many other types of cells and may be hiding out in the patient's body to resurface at a later time, he said.

So I'd think it's pretty important to have the stem cells still there to still be producing the resistant T cells.

[baldguy]

2. More proof that stem cell therapy is the devils' work.

After all, the only good hoamiseckshul is a ded hoamiseckshul!

'Tis a sin of PRIDE to claim you can "cure" Gawd's Judge-ee-ment!

[Sebastian Doyle]

3. Yeah, I'm sure Fred Phelps is already screen printing his new signs

GOD HATES MEDICAL SCIENCE !!!!!!!11!!

[nebenaube]

4. hmmm

This makes me wonder if they didn't erradicate it when they killed the bone marrow during prep.

[Liberal Veteran]

6. I think that's a possibility.

Of course, for those already infected for a long time who have progressed to needing treatment, I'm not sure how good that treatment would work if the "cure" worked because of the introduction of the CCR5 mutation.

HIV tends to start out as CCR5 tropic virus (meaning it enters the cell using CCR5 co-receptor), and as infection progresses, it changes to CXCR4 tropic and dual-tropic virus. So granting resistance via the CCR5 mutation isn't going to do much good for those who have dual-tropic or CXCR4 tropic virus.

I'm hoping there is something else at work here other than a radical form of chemotherapy (completely rebooting the immune system through chemical suppression) or the conference of CCR5 mutation.

Kind of a grasp at straws, but it would be great if we found something else that could be used as a viable and not so dangerous way of eradication. Logically, the simplest explanations are those discussed, but one can hope for an unexpected discovery.