[Antigenic specificity of antiplasmodium antibodies in an endemic area: an attempt at correlation with the induction of protective immunity].

Abstract

Asexual blood-stage antigens from Plasmodium falciparum related to the development of protective immunity in an endemic area were identified by statistical comparison of antigens recognized by adult immune sera with those recognized by non-immune subjects (children). After metabolic labelling of parasites in culture and immunoprecipitation, target antigens of seric antibodies were separated by polyacrylamide gel electrophoresis/SDS and detected by fluorography. Two groups of antigens were thus identified: 1) the major bands, recognized by more than 90% of the sera regardless of the patients' immune status; and 2) the minor bands, less intense on fluorograms. The corresponding antibodies were more frequent in children who had not yet acquired protective immunity than in immune adults. Thus, these minor bands do not appear essential for protection, which might instead be related to the presence of some major antigens, such as 210/196-, 136-, 121- and 80-Kd antigens. These antibodies persist for at least one year, independently of fluctuations in the rate of transmission by Anopheles.