By Billie Rubin, Hemoglobin’s Catabolic Cousin, reporting from the labs of Stanford Blood Center
Red blood cell (RBC) antigens have to be good for something – nature doesn’t make useless things for no reason. We have similar ABO antigens to some on bacteria, pollen, grains, etc., and these may be involved in stimulating the production of our natural anti-A and anti-B antigens.
RBCs have another antigen system as well called “Duffy” (abbreviated as Fy); one of about 29 systems of antigens like the ABO system. The most common antigens in the Duffy system are Fya and Fyb. Most people have one or both and it’s quite rare to lack both.
Well, it seems that some malaria sub-types (Plasmodium vivax and Plasmodium knowlesi, for example) can get inside RBCs via these Fy antigens (like a hand-hold). There is a large percentage of people in Africa or of African descent, however, that are of the rare type that lack Fy antigens. If you don’t have Fy antigens, you stand a better chance against these types of malaria and your descendants have an evolutionary edge on survival. Very interesting…