Red blood cells are resistant to Plasmodium vivax malaria when they lack which specific antigen?

The resistance of red blood cells to Plasmodium vivax malaria is specifically associated with the absence of the Duffy antigen. Plasmodium vivax, unlike other malaria species, requires the Duffy antigen for its invasion of red blood cells. When red blood cells lack this antigen, the malaria parasite is unable to attach and enter the cells, thus providing a form of resistance against the infection.

The Duffy antigen is a glycoprotein present on the surface of red blood cells and plays a crucial role in the binding of P. vivax during the life cycle of the parasite. Populations in regions with high malaria prevalence often exhibit a higher frequency of individuals who are Duffy antigen negative, which contributes to their resistance to this specific form of malaria.

In contrast, other antigens mentioned, such as the Rh antigen, Jk antigen, and Lewis antigen, are not directly involved in the invasion of red blood cells by P. vivax. While variations in these antigens might have clinical relevance in transfusion medicine or other contexts, they do not confer the same level of specific resistance to malaria parasites as the absence of the Duffy antigen does.