Genetic polymorphisms of CYP2B6*6, CYP2C8*3 and CYP2D6*4 in vivax malaria patients from Brazilian Amazon

Genetic variability in the host metabolism of antimalarial drugs influenced by the polymorphisms of cytochrome P450 (CYP) could lead to significant changes in antimalarial treatment response. However, little is known about the frequency of alleles CYP2B6, CYP2C8, and CYP2D6 in an Amazonian population, especially with vivax malaria. Therefore, this study aimed to determine the frequency of CYP alleles CYP2B6*6, CYP2C8*3, and CYP2D6*4 in patients with vivax malaria. The study included 231 patients with vivax malaria treated at a health care reference in Manaus, northern Brazil. A sample of peripheral blood from each subject was collected to perform DNA extraction and genotypic analysis. Genotyping of polymorphisms was performed by allelic discrimination using Real-time polymerase chain reaction. The CYP2D6*4 allele was the most prevalent among patients who developed severe malaria. The frequencies of the CYP2B6*6 and CYP2D6*4 were not different between the severe and uncomplicated malaria. There was a significant association between heterozygous CYP2D6*4 and severe cases of malaria. The results are in agreement with other reports described in the literature for different populations. Future studies are needed to understand the clinical implications of the polymorphisms in patients with vivax malaria.