It has long been known that people with blood type O are protected from dying of severe malaria. In a study published in Nature Medicine, a team of Scandinavian scientists explains the mechanisms behind the protection that blood type O provides, and suggest that the selective pressure imposed by malaria may contribute to the variable global distribution of ABO blood groups in the human population.
A team of scientists led from Karolinska Institutet in Sweden have now identified a new and important piece of the puzzle by describing the key part played by the RIFIN protein. Using data from different kinds of experiment on cell cultures and animals, they show how the Plasmodium falciparum parasite secretes RIFIN, and how the protein makes its way to the surface of the blood cell, where it acts like glue. The team also demonstrates how it bonds strongly with the surface of type A blood cells, but only weakly to type O.
This study ties together previous findings. It can explain the mechanism behind the protection that blood group O provides against severe malaria, which can, in turn, explain why the blood type is so common in the areas where malaria is common. In Nigeria, for instance, more than half of the population belongs to blood group O, which protects against malaria.”
How blood group O protects against malaria