African gene increases odds of HIV infection

[Guest guest]

African gene increases odds of HIV infection

Washington | July 17, 2008 12:35:06 PM IST

A gene variant found only in people of African ancestry increases the

chances of becoming infected with HIV-1 by 40 percent, according to a

long-term study.

Interestingly, however, after infection, the same variant seemed to

protect against progression of the disease, allowing those who carry

it to live about two years longer.

It's well-known that individuals vary in their susceptibility to HIV

and that after infection occurs, the disease progresses at variable

rates, said Sunil Ahuja of the University of Texas Health Science

Centre.

The mystery of variable infection and progression was originally

thought to be mainly the result of viral characteristics, but in

recent years it has become evident that there is a strong host

genetic component.

The new discovery is one of few genetic risk factors for HIV found

only in people of African descent, the researchers added. If the new

findings can be extrapolated to Africa, where about 90 percent of all

people carry the variant, it may be responsible for 11 percent of the

HIV burden there, they estimate.

The gene in question encodes a protein found mainly at the surface of

red blood cells, which is called Duffy Antigen Receptor for

Chemokines (DARC).

The DARC variant found commonly in people of African ancestry leaves

them without this particular red blood cell receptor. That so-

called " DARC-negative " condition has been well studied because it

also confers protection against infection by a malaria parasite known

as Plasmodium vivax.

The big message of this paper is that something that protected people

against malaria in the past is now leaving them more susceptible to

HIV, " said Robin Weiss of University College London.

The findings have been published in the latest issue of the journal

Cell Host & Microbe. St/jg

(322 Words)17071210NNNN (IANS)

--- End forwarded message ---

[Guest guest]

African gene increases odds of HIV infection

Washington | July 17, 2008 12:35:06 PM IST

A gene variant found only in people of African ancestry increases the

chances of becoming infected with HIV-1 by 40 percent, according to a

long-term study.

Interestingly, however, after infection, the same variant seemed to

protect against progression of the disease, allowing those who carry

it to live about two years longer.

It's well-known that individuals vary in their susceptibility to HIV

and that after infection occurs, the disease progresses at variable

rates, said Sunil Ahuja of the University of Texas Health Science

Centre.

The mystery of variable infection and progression was originally

thought to be mainly the result of viral characteristics, but in

recent years it has become evident that there is a strong host

genetic component.

The new discovery is one of few genetic risk factors for HIV found

only in people of African descent, the researchers added. If the new

findings can be extrapolated to Africa, where about 90 percent of all

people carry the variant, it may be responsible for 11 percent of the

HIV burden there, they estimate.

The gene in question encodes a protein found mainly at the surface of

red blood cells, which is called Duffy Antigen Receptor for

Chemokines (DARC).

The DARC variant found commonly in people of African ancestry leaves

them without this particular red blood cell receptor. That so-

called " DARC-negative " condition has been well studied because it

also confers protection against infection by a malaria parasite known

as Plasmodium vivax.

The big message of this paper is that something that protected people

against malaria in the past is now leaving them more susceptible to

HIV, " said Robin Weiss of University College London.

The findings have been published in the latest issue of the journal

Cell Host & Microbe. St/jg

(322 Words)17071210NNNN (IANS)

--- End forwarded message ---