Acquisition and decay of antibodies to pregnancy-associated variant antigens on the surface of Plasmodium falciparum-infected erythrocytes that protect against placental parasitemia
T. Staalsoe et al., Acquisition and decay of antibodies to pregnancy-associated variant antigens on the surface of Plasmodium falciparum-infected erythrocytes that protect against placental parasitemia, J INFEC DIS, 184(5), 2001, pp. 618-626
Otherwise clinically immune women in areas endemic for malaria are highly s
usceptible to Plasmodium falciparum malaria during their first pregnancy. P
regnancy-associated malaria (PAM) is characterized by placental accumulatio
n of infected erythrocytes that adhere to chondroitin sulfate A (CSA). Susc
eptibility to PAM decreases with increasing parity, apparently due to acqui
sition of antibodies directed against the variant surface antigens (VSAs) t
hat mediate the adhesion to CSA (VSA(CSA)). This study found that levels of
VSA(CSA)-specific antibodies depend on endemicity, that anti-VSA(CSA) IgG
is acquired during gestation week 20, and that plasma levels of the antibod
ies decline during the postpartum period. There is evidence that VSA(CSA)-s
pecific antibodies are linked to placental infection and that high antibody
levels contribute to the control of placental infection by inhibiting para
site adhesion to CSA. Data suggest that VSA(CSA) is a target for vaccinatio
n against PAM.