Maternal and neonatal immune responses to Plasmodium falciparum infection

Plasmodium falciparum infection during pregnancy has severe consequences for both mother and fetus and can lead to the trans-placental passage of malarial antigens that are capable of inducing neonatal immune responses. Between July 2003-December 2004, 228 women from Omdurman Maternity Hospital, Sudan were followed monthly during antenatal period till delivery time. We examined neonatal and maternal cytokine and antibody responses to merozoite surface protein-1(MSP1-19) in infant-mother pairs. ELISA sero-positivity rate in the maternal plasma samples was 48.9 % and 31.1% for the cord blood samples. Anti-MSP-119 IgG at time of delivery in neonates whose mothers had malarial infections during antenatal period was higher (p=0.000) than those who were parasite negative. In response to P. falciparum antigen peripheral blood mononuclear cells (PBMCs) produced significantly higher level of IFN-γ (p = 0.0001) than that of the paired cord blood cells (CBMCs). PBMCs from mothers infected during the antenatal period secreted significantly more IFN -γ (p=0.0001) and decreased IL-10 production (p=0.005) than non infected women. A mixed Th1/Th2 immune response was seen most commonly in women who had confirmed positive blood films P. falciparum infections; on the other hand neonates born of malaria-positive mothers mounted predominantly Th2 type immune responses as detected in their cord blood.