Cytokine Analysis And Drug Resistance Associated Genetic Polymorphism In Plasmodium Vivax

Abstract

Introduction: Malaria is a vector born disease of major public health concern in several tropical and subtropical countries. Five different plasmodium species are known to cause malaria. For optimal public health measures, region specific prevalence of plasmodium species should be identified by optimal diagnostic methods available. Inflammatory cytokines play an important role in human immune responses to malaria. There should be cytokine balance between pro-inflammatory and anti-inflammatory cytokines. If there is dysregulation, amongst these pro-inflammatory and anti-inflammatory cytokines, it will lead to pathogenic effects. Major obstacle in the malaria prevention and eradication is the emergence of resistance in parasites towards many anti-malarial drugs. This significantly compromise the strategies used in controlling the infection. Aims and Objectives To study the prevalence of P.vivax and P.falciparum infections among suspected malaria cases and to analyze pro-inflammatory and anti-inflammatory cytokines implicated in malaria such as TNF-α, IFN-γ and IL-10, and TGF-β and to identify the mutation in drug resistance genes; pvmrd1 and pvdhfr of Plasmodium vivax clinical isolates to understand drug resistance pattern. Material and methods: A cross sectional study was conducted in 600 clinically suspected malaria cases. All the blood samples were screened by conventional PBS microscopy and rapid diagnostic tests (RDT). Blood samples positive for malaria were subjected to detection of cytokines TNF-α, IFN-γ, IL-10, and TGF-β by ELISA. Molecular confirmation of P.vivax and detection of pvmdr-1 gene and pvdfhr gene responsible for drug resistance in P.vivax were analysed. . Statistical analysis: Data will be analysed using SPSS software (version 20). The percentage analysis of the data will be given.Results: A total of 600 blood samples of malaria symptomatic cases were screened. 45 samles were found to be positive for malaria by microscopic observation and 51 samples by antigen detection by RDTs and 36 samples by PCR. Out of these 45 positive cases 33 (73%) were caused by P. vivax, 10 (22.2%) by P. falciparum and 2 (4.4%) were of mixed infection (P. vivax + P. falciparum) cases. Both the selected pro-inflammatory (TNF-α and IFN-γ) and anti-inflammatory (IL-10 and TGF-β) markers in the present study were found to be significantly elevated in malaria cases compared to healthy controls. In this study most of the P.vivax isolates had mutations in T958M (94.4%) & F1076L (83.3%) was observed and one isolate had mutations in Y976F (2.7%) pvmdr1 and wild type single type mutation in S58R and S117N amino acid positions of pvdhfr genes. Conclusion: The present study detected the presence of SNPs in both pvmdr-1 and pvdhfr gene in the selected geographical area. The frequency of mutations in these genes does not indicate the development of complete resistance to chloroquine and sulfadoxine-pyrimethamine in P. vivax. However, few SNPs detected in both genes suggested the probable early phase of resistance development.