Duffy blood system and g6pd genetic variants in p. Vivax malaria patients from manaus, amazonas, brazil

Abstract

Background Over a third of the world’s population lives at risk of potentially severe Plasmodium vivax induced malaria. The unique aspect of the parasite’s biology and interactions with the human host make it harder to control and eliminate the disease. Glucose-6-phosphate dehydrogenase (G6PD) deficiency and Duffy-negative blood groups are two red blood cell variations shown to confer protection against malaria. Methods Molecular genotyping of G6PD and Duffy was performed in 225 patients with severe and non-severe malaria randomly admitted at a reference center for infectious disease from Manaus. For G6PD variants characterization of the variants, Real Time PCR (qPCR) was performed, while Duffy genotyping by PCR-RFLP. Results Of the 225 patients, 29 (12.94%) and 43 (19.19%) were carriers of the G6PD c.202G > A and c.376A > G, respectively. For the Duffy genotype (c.-67T > C in the GATA promoter region), 70 (31.11%) were phenotyped as Fy(a + b-), 98 (43.55%) Fy(a + b+), 56 (24.9%) Fy(a-b+) and 1 (0.44%) Fy(a-b-). The FY*01/FY*02 genotype was prevalent in both non-severe and severe malaria. In women, the FY*01/FY*02 allele occurred concomitantly with c.376A > G more frequently in non-severe malaria, while in men, this combination was predominant in severe malaria. Duffy phenotype Fy(a-b+) (p = 0.022) and genotypes FY*01/FY*01 / FY*02/FY*02 (p = 0.015) correlated with high parasitemia density before and after treatment. Conclusions Our results showed only one uncomplicated vivax malaria patient with Duffy phenotype Fy(a-b-). Heterozygous GATA variants did not confer protection against malaria infection in this study. Research on G6PD and Duffy antigen deficiencies has been valuable, particularly when focused on densely populated areas. Our results confirm possible genetic molding mechanisms in vivax malaria in our Amazon region and can help to improve the understanding of the relationship between G6PD deficiency and Duffy genotypes concomitantly in the protection or susceptibility to P. vivax infection. Molecular diagnosis before treatment may be necessary in the Amazonian population, regardless of the diagnosis of uncomplicated or severe malaria.