Study shows risk for hiv infection dependant on blood group

[hivsweden]

The risk of being infected by HIV may be determined by the presence of a molecule in a person’s blood cells, according to a discovery made by Swedish scientists working as part of an international research team.

Individuals with high levels of the molecule, of the carbohydrate-based blood group known as Pk, were found to exhibit a much greater natural resistance to HIV infection, while those lacking the molecule were more easily infected by the virus which causes AIDS.

“We found dramatic difference. If you don’t have the molecule, it can be up to 1000 times easier to become infected by HIV. Those who have high levels of the molecule are more or less resistant [to the virus],” said Martin L. Olsson, a doctor at Lund University’s Faculty of Medicine, to the TT news agency.

There are many more ways of grouping blood in addition to the well-know ABO and Rhesus systems.

While one's Pk-level can be used as a way to classify one's blood-type, the grouping isn’t used routinely today.

Pk-levels vary from person to person, which may explain in part why susceptibility to HIV infection varies so much within the population.

Approximately one in every million people is thought to have high enough Pk-levels to be considered resistant to the HIV virus.

Olsson believes the discovery will lead to new treatment for HIV and AIDS.

One possible use is to raise levels of the molecule or increase an individual’s ability to create it among those who have been exposed to HIV in order to reduce the risk of an infection taking hold.

“There actually is a molecule which has been developed by our Canadian partners which in principle is a loose variant of the molecule. In cellular trials they’ve applied it and seen that it hinders the infection,” said Olsson.

The discovery may also be used to diagnose which people have high or low risk of being infected by HIV.

According to the researchers, their findings mark only the second discovery of a natural form of resistance against HIV.

Unlike the earlier discovery, however, the Pk-based method applies to all known variations of the HIV virus.

The results of the study were published on Monday in Blood Journal.
TT/David Landes (news@thelocal.se)


http://www.thelocal.se/16862/

[hotpuppy]

Very cool.  Thanks for posting it.

[bocker3]

I'm a little confused by this --  I've worked in Blood Banks and have never heard of a Pk antigen on RBCs.  I did a quick google and all I find is info on an enzyme red-blood cell type PK (pyruvate kinase). 
I could not understand how an antigen on RBC's would impact HIV infection, so I'm thinking that the author of this article saw the word "type" and associated it with blood cell typing. 
So, it seems (again, I just did a quick search) that it is NOT about blood type, but about an enzyme produced by RBCs.  THis probably isn't important to most, but it helped clear up a seemingly crazy connection to me.

Mike

[hivsweden]

Mike,

I found another article:
http://www.scientistlive.com/European-Science-News/Biotechnology/New_weapon_in_battle_against_HIV/21540/

New weapon in battle against HIV

Date: 13/01/2009
Researchers have discovered a potentially important new resistance factor in the battle against HIV: blood types. An international team of researchers from Canadian Blood Services, The Hospital for Sick Children (SickKids) and Lund University in Sweden have discovered that certain blood types are more predisposed to contracting HIV, while others are more effective at fending it off.
A carbohydrate-containing antigen, termed Pk blood group which is distinct from the well-known ABO and Rh blood grouping systems, is present at variable levels on the surface of white and red blood cells in the general population. A study published today in Blood, which is currently available online, shows that cells from rare individuals (≈ 1 in a million) who produce excess of this blood group antigen have dramatically reduced sensitivity to HIV infection. Conversely, another slightly more common subgroup of people who do not produce any Pk (≈ 5 in a million) was found to be much more susceptible to the virus.

"This study is not suggesting that your blood type alone determines if you will get HIV," says lead author Dr. Don Branch of Canadian Blood Services. "However, it does suggest that individuals who are exposed to the virus, may be helped or hindered by their blood status in fighting the infection."

Increasing the level of the Pk antigen in cells in the laboratory also resulted in heightened resistance to HIV, while lowering it increased susceptibility. The Pk molecule has been previously studied extensively by The Research Institute at the Hospital for Sick Children Senior Scientist Dr. Cliff Lingwood; Lund University's Dr. Martin Olsson has identified underlying genetic reasons for Pk blood group variation.

"This discovery implicates the Pk level as a new risk factor for HIV infection and demonstrates the importance of blood-group-related science," says Dr. Olsson.

"The conclusions of this study pave the way for novel therapeutic approaches to induce HIV resistance and promote further understanding of the pandemic as a whole," says Dr. Lingwood.