Relationships between clinical protection and antibodies to Plasmodium falciparum RESA (ring-infected erythrocyte surface antigen) peptides.

A longitudinal study involving 76 individuals living in Dafinso and Vallée du Kou (near Bobo-Dioulasso, Burkina Faso, West Africa) was performed in June 1987 (beginning of the transmission period), August-September 1987 (during) and January 1988 (after). The serological antibody (Ab) responses against synthetic peptides representing repeat amino acid sequences of the P. falciparum Ring-Infected Erythrocyte Surface Antigen (RESA): (EENV)5, (EENVEHDA)4, (DDEHVEEPTVA)2 were evaluated by ELISA. The clinical longitudinal study during the transmission period allowed us to define three different groups in terms of age and occurrence of clinical malarial attack (greater than 5000 parasites mm-3 of blood and axillary fever greater than 37.7 degrees C). Levels (A620) of Ab to (EENVEHDA)4 and (DDEHVEEPTVA)2 were correlated with age. The adult group (III) had the highest prevalences of Ab to RESA peptides. No significant difference was found between groups of children with or without malaria attack. Nevertheless, at the beginning of the transmission period, children who had at least one malaria attack during the study presented the lowest level of antibodies to RESA peptides.