Associações entre os fenótipos ABO, RhD, mutações da proteína Duffy e a malária vivax em habitantes do estado do Amazonas, Brasil

Abstract

Associações entre os fenótipos ABO, RhD, mutações da proteína Duffy e a malária vivax em habitantes do estado do Amazonas, BrasilAssociations of the ABO blood group, Rh antigen and Duffy protein mutations with vivax malaria in inhabitants of the Amazonas State, Brazil antigen) and the GATA box mutation -33(T>C)] with vivax malaria in inhabitants of the state of Amazonas, Brazil, an endemic area for malaria. Identification of Plasmodium vivax and the measurement of parasitemia were achieved by standard screening tests and clinical evaluations of 497 patients in which ABO, RhD and Duffy phenotyping was performed, as was Duffy blood group genotyping using PCR/RFLP reactions. These results were compared with previously published data of the same variables in blood donors from the Brazilian Amazon without any history of malaria. Our data show that the presence of the A antigen and FYA/FYB-33 and FYB/FYB-33 genotypes in the population may give a selective advantage, thereby reducing the P. vivax infection rate in this region, however without association with the parasite load of vivax malaria infection. We did not find associations between the RhD antigen and P. vivax susceptibility however the presence of the FYA/FYB and FYA/FYA genotypes proved to be associated with an increase in the P. vivax infection rate in this region. The FYB/FYX and FYA/FYX genotypes did not have any association with the P. vivax infection rate, but they proved to be associated with low parasite loads found among infected patients with these genotypes. In this study we identified only two FYB-33/FYB-33 individuals with histories of malaria vivax. These results suggest that natural adaptation in malaria endemic regions may lead to the emergence of partial defense mechanisms against P. vivax different to those already described in Africans descendents, and additionally, other adaptations may increase the susceptibility to this type of malaria. Avaliação: A RBHH publica os resumos e abstracts de teses da área apresentados em entidades que tenham programas de pós-graduação reconhecidos pelo MEC/Capes e considera a obtenção do título suficiente para sua publicação na forma como se propõe a seção. REVISTA BRASILEIRA DE HEMATOLOGIA E H E M O T E R A P I A REVISTA BRASILEIRA DE HEMATOLOGIA E H E M O T E R A P I

Malaria and Vascular Endothelium

“…They are also involved in hemolytic transfusion reactions and in the hemolytic disease of the newborn 13 . In the Amazon state, the genotypes FYA/FYB and FYA/FYA of the Duffy antigen were associated with an increase in P. vivax infection 14 .…”