Cytokine Gene Polymorphisms and Parasite Drug Resistance Mutations Among Malaria Gametocyte Carriers and Non-carriers in Southern Ghana

Abstract

Malaria is a disease caused by protozoan parasites of the Plasmodium spp. The transmission of the parasites is influenced by human and parasite factors that initiate specific immune response. IL10, IFN-γ, and nitric oxide have been suggested to play a role in parasite elimination within the host. Drug resistant parasites have been shown to prolong the longevity of parasites within the host and hence given parasites ample time for gametocyte formation and transmission. This study sought to investigate the human cytokine gene polymorphisms (IL10-592C/A, NOS2-1173C/T, and IFN γ+874T/A) and drug resistance mutations (Pfmdr1 N86Y, Pfdhfr N51I, and Pfdhfr S108N) among gametocyte carriers and non-carriers in southern Ghana. A total of 192 archived samples with gametocyte data from previous studies were genotyped for the various cytokine gene polymorphisms and parasite drug resistance mutations using PCR-RFLP technique. There were high frequencies of the IL10-592C/A (p= 0.001) and IFN-γ+874T/A (p< 0.001) SNPs compared to their respective normal genotypes with only 3 (1.92%) individuals showing the NOS2-1173C/T SNP. The Pfdhfr S108N mutation was dominant in the study population with significantly higher frequencies among gametocyte carriers (p= 0.001). These findings provide a basis for functional and further genetic studies of the two SNPs to ascertain their influence in malaria transmission.