Thursday, December 16, 2010

Stem cell HIV fix

"

HIV-positive man ‘cured’ by stem cell transplant

The man received bone marrow from a donor who had natural resistance to HIV infection; this was due to a genetic profile which led to the CCR5 co-receptor being absent from his cells," they explained. "The most common variety of HIV uses CCR5 as its ‘docking station’, attaching to it in order to enter and infect CD4 cells, and people with this mutation are almost completely protected against infection.

...stem cells from a donor that lacked the CCR5 receptor, "a condition that is present in less than 1 percent of Caucasians in northern and western Europe...
"

The complete case history can be found at aidsmap.com.

And we will probably never hear about this in the mainstream media unfortunately.

2 Reflections:

Kieran said...

Found this comment on Reddit about the story.

"This is actually old news (see http://online.wsj.com/article/SB122602394113507555.html), and not really that surprising and/or miraculous considering what the "cure" actually entails - a bone marrow transplant.

A certain percentage of the human race has innate immunity to HIV (~1%) through a mutation which prevents a molecule called CCR5 from appearing on the surface of your cells. In most people, this molecule signals HIV to bind and enter cells - hence, if you lack CCR5, then HIV can't see you and won't affect you. There are several new anti-HIV drugs that target CCR5, (called CCR5 antagonists), which attempt to disrupt this interaction.

If you happen to be a leukemia patient with HIV (as was the case here) and you receive a bone marrow transplant from someone who has this innate immunity, chances are you will be effectively cured of your HIV infection because you are replacing your own immune system with that of the donor. A bone marrow transplant is HIGHLY invasive, and often does not work. The recipient is first blasted with very powerful chemotherapy to literally kill that person's bone marrow. During this stage the person is incredibly vulnerable to secondary infection because they have no adaptive immune response. Then, the recipient is injected with donor bone marrow stem cells, which in theory, will recolonize the bone tissue and eventually take over the immune response. In the case of this one patient, it appears that this is what happened.

Consequently, this is NOT a practical cure for HIV - though it is a very interesting proof of concept."

Rocko Chen said...

Thanks Kieran, I understand this much better now.