Impact of submicroscopic infection due to Plasmoduim falciparum on the expression profile of three chemokines in women giving birth in a Health Center in Yaoundé, Cameroon

Microscopic Plasmodium falciparum infection in pregnant women is associated with the inflammation of the placental tissue, characterized by the alteration of chemokine and cytokine profile expression, and increased risk of adverse pregnancy outcomes. The objective was to determine the impact of the submicroscopic infection due to Plasmodium falciparum diagnosed by the RT-LAMP biomolecular technique on the expression of three chemokines in women at delivery, and to investigate the consequences on pregnancy outcomes. This cross-sectional study was carried out at the Marie Reine Medical Health Center of Etoudi, Yaounde, where peripheral, placental and cord blood samples, as well as small pieces of the placenta tissue were collected in 134 women immediately after delivery and their babys’ weights measured. Placental malaria was diagnosed by microscopic examination of the placental tissue impression smear while submicroscopic peripheral blood infection was diagnosed using the biomolecular RT-LAMP technique. Plasma chemokine concentrations CXCL-13, CXCL-16, CCL-24 in peripheral, placental and cord blood were determined using the Multi Analyte Platform Assay. The results showed that, plasma concentration of CXCL-16 and CCL-24 in placental blood and CCL-24 in peripheral blood were lower in women with submicroscopic infection compared to uninfected women (p = 0.01, p=0.02, p=0.09 respectively). Furthermore, elevated plasma concentrations of CCL-24 in peripheral, placental and cord blood were associated with an increase in baby haemoglobin levels (p = 0.0003, 0.01, 0.004 respectively). The high concentrations of CXCL-13 in peripheral blood was associated with a decrease in the baby weights (p = 0.005) while elevated levels of CXCL-16 in the cord blood correlated with a decrease in baby haemoglobin levels (p=0.01). The overall results suggest that submicroscopic infection is associated with a decrease in CCL-24 expression, a chemokine believed to play an important role for the maintenance of normal haemoglobin levels in babies at birth.
Keywords: Submicroscopic infection, Chemokines, Plasmodium falciparum, RT-LAMP,
Women, Delivery