Pro- and anti-inflammatory cytokine profiles in Plasmodium Falciparum-infected individuals from Baiyeku, Ikorodu, Lagos, Nigeria

Abstract

Available evidence indicates that the various stages of the malaria parasite life cycle elicit specific immune responses of which the relative levels of pro-inflammatory cytokines are key to disease progression, killing the parasite and mediating disease outcomes. This study investigated T-cell response in malaria. Four hundred and sixty-two participants were screened in a community survey of Plasmodium falciparum malaria in Baiyeku, Lagos, Nigeria. P. falciparum parasitaemia was determined by microscopy while the serum levels of IL-10, IFNγ and TNFα were determined by Enzyme-linked immunosorbent assay (ELISA). A total of 70 (15.2 %) participants were microscopically positive for P. falciparum of which 70% were females, 30% were males while children aged 1-17 years were 65.7%. The geometric mean parasite density (GMPD) was significantly (p=0.001) higher among females than males. The GMPD of participants <5 years of age was also significantly (p=0.001) higher than other age groups. About 46.8% of the participants were underweight (Body Mass Index, BMI < 18.5) and also had the highest parasite intensity. The TNFα, IFNγ and IL-10 levels were significantly (p< 0.05) higher in the infected than the uninfected participants. IFN-γ values were significantly (p=0.014) elevated among the symptomatic than the asymptomatic participants while there was no significant difference (P>0.053) in the levels of TNF-α and IL-10 (P>0.093) between the symptomatic and asymptomatic participants. The prevalence of P. falciparum obtained in this study area which is endemic to malaria is 15.2% suggesting a significant reduction of the disease over time due to awareness of the disease in the community. The levels of pro-inflammatory cytokines (IFN-γ and TNF-α) in this study were lower due to the down-regulatory action of the anti-inflammatory cytokines (IL-10). These findings suggest that higher levels of anti-inflammatory cytokines, especially IL-10 levels may contribute to the pathogenesis of uncomplicated malaria.