Total and functional parasite specific IgE responses in Plasmodium falciparum-infected patients exhibiting different clinical status

Abstract

Blood samples were collected from controls and P. falciparum-infected patients before treatment on the day of hospitalization (day 0) in India and, in addition, on days 7 and 30 after treatment in Gabon. Total IgE levels were determined by ELISA and functional P. falciparum-specific IgE were estimated using a mast cell line RBL-2H3 transfected with a human Fcε RI α-chain that triggers degranulation upon human IgE cross-linking. Mann Whitney and Kruskall Wallis tests were used to compare groups and the Spearman test was used for correlations. Total IgE levels were confirmed to increase upon infection and differ with level of transmission and age but were not directly related to the disease phenotype. All studied groups exhibited functional parasite-specific IgEs able to induce mast cell degranulation in vitro in the presence of P. falciparum antigens. Plasma IgE levels correlated with those of IL-10 in uncomplicated malaria patients from Gabon. In Indian patients, plasma IFN-γ , TNF and IL-10 levels were significantly correlated with IgE concentrations in all groups