Recombinant polypeptides for serology of malaria

We have evaluated 3 molecularly defined polypeptides encoded by encloned Plasmodium falciparum genes for their ability to serve as antigens for detecting antimalaria antibodies. The recombinant proteins correspond to (i) a conserved part of 190-200 kDa schizont merozoite surface component, (ii) the carboxy terminal part of the P. falciparum aldolase, and (iii) the 5.1 antigen. Antibodies were detected using enzyme-linked immunosorbent assays (ELISA) in a high percentage of sera from individuals from a malaria endemic area in The Gambia (up to 99% for some adult groups). These results were further improved, especially for detection of antimalaria antibodies in children, when a pool of all 3 polypeptides (ELISA MIXT) was used as antigen. This ELISA MIXT improves presently available assays for the detection of antimalaria antibodies directed against asexual blood stages in respect of standardization, sensitivity and specificity.