Impact of placental malaria on maternal, placental and foetal cord responses and its role in pregnancy outcomes in women from Blue Nile State, Sudan

Abstract

Background The sequestration of Plasmodium falciparum infected cells in the placenta results in placental malaria (PM). It activates the mother's immune cells and induces secretion of inflammatory cytokines, which might influence pregnancy outcomes. This study aims to investigate the inflammatory environment in maternal peripheral, placental, and umbilical cord blood in response to PM and the extent to which this may influence maternal haemoglobin levels and birth weight.Methods A total of 185 consenting Sudanese women from Blue Nile state were enrolled in a cross sectional conducted between Jan 2012-Dec 2005. Malaria infection in the collected samples was determined microscopically, and ELISA was used to measure the plasma levels of the antibodies, IL-4, IL-6, IL-10, IL-17A, and INF γ in the collected positive and negative malaria samples. Results Elevated levels of antibodies, IL-4 and IL-10 and reduced levels of IL-6 were detected in the malaria positive samples in comparison to the negative ones in the three types of samples investigated. Maternal antibodies, IL-4 and IL-10 were significantly higher in the samples collected from the PM infected group compared to the non-infected control (P < 0.001). While the absence of PM was significantly associated with the IL-6 and maternal IFN-γ levels, maternal IL-17A, placental and umbilical cord IFN-γ levels showed no significant difference (P=0.214, P=0.065, P=0.536, respectively) due to infection. Haemoglobin level and birth weight were increased in the group with high levels of IL-6 and IL-17A, but not in the group with IL-4 and IL-10 levels. While significantly negative correlation was found between IFN-γ levels and birth weight for all three types of samples, only maternal peripheral FN-γ level was significantly positively correlated with maternal haemoglobin (r= 0.171, P =0.020).Conclusion These results suggest that PM cross-reacts with the mother’s immune response and impairs her cytokine profile, which might alter maternal haemoglobin levels and the baby's birth weight.