Researchers identify potential new weapon in battle against HIV

An international team of researchers from Canadian Blood Services, Toronto’s Hospital for Sick Children (SickKids), and Lund University in Sweden have discovered that certain types of blood are more predisposed to contracting HIV, while others are more effective at fending it off.

A carbohydrate-containing molecule termed the 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. A study to be published in the leading journal Blood, shows that cells from rare individuals who produce excess of this blood group have dramatically reduced sensitivity to HIV infection.

Conversely, another slightly more common subgroup of people who do not produce any Pk at all was found to be much more susceptible to the virus. Interestingly, Pk levels also vary substantially in the general population.

“This study is not suggesting that your blood type alone determines if you will get HIV,” said principal 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 type in fighting the infection.”

Increasing the level of the Pk blood group 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 Sick Kids’ Dr. Cliff Lingwood, and 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.