Dynamics of PfEMP 1 Antibody Profile From Birth to 12 Months of Age in Beninese Infants

Background. Plasmodiumfalciparum-infected erythrocytes bind to specific endothelial cell receptors via members of the PfEMP1 family exported onto the erythrocyte surface. These interactions are mediated by different types of cysteine-rich interdomain region (CIDR) domains found in the N-terminal region of all PfEMP 1 . CIDR alpha 1 domains bind endothelial protein C receptor (EPCR), CIDR alpha 2-6 domains bind CD36, whereas the receptor specificity of CIDR beta/gamma/delta domains is unknown. Methods. In this study, we investigated the level of immunoglobulin (Ig)G targeting the different types of PfEMP1 CIDR during the first year of life. We used plasma collected longitudinally from children of pregnant women who had been followed closely through pregnancy. Results. Antibodies to CIDR alpha 1 domains were more frequent in cord blood compared with antibodies to CIDR alpha 2-6 domains. Higher IgG levels to EPCR-binding CIDR alpha 1 variants positively correlated with the timing of first infections. Antibodies to all PfEMP1 types declined at similar rates to the point of disappearance over the first 6 months of life. At 12 months, children had acquired antibody to all types of CIDR domains, mostly in children with documented P falciparum infections. Conclusions. These observations agree with the notion that the timing and phenotype of first P falciparum infections in life are influenced by the immune status of the mother.