Duffy antigen receptor for chemokines (DARC) and susceptibility to Plasmodium vivax malaria.

DARC is thought to act as a key invasion receptor in P. vivax malaria. It is known that the expression of DARC and susceptibility to P. vivax malaria is influenced by the presence of specific DARC genotypes. Studies have reported the low probability of P. vivax malaria in individuals carrying FyA allele due to the significantly reduced binding of the P. vivax duffy binding protein. No association of the allele frequency and severe vivax malaria epidemiology has been yet established in our country. In the present study, a high level of heterozygotes was observed with a statistically significant deviation from the H-W equilibrium in the group with complicated malaria; which is indicative of demographic disequilibrium. Significantly upregulated expression of the DARC receptor in FyA/FyB heterozygote patients is suggestive of a greater receptor repertoire responsible for the possible variation in the parasite ligand binding with the host receptor and thus might have a role to play in severe malaria.