[Re-assessment of culture inhibition assays and reinvasion of P. falciparum for the appraisal of immunity of individuals living in an endemic area].

We conducted an analysis to reevaluate the in vitroculture inhibition assays as a reliable criteria of functional activity of anti-P. falcipanrm antibodies in premunized individuals. Several strains of P. falcipanrm adapted to in vitro culture were compared, and various technical conditions of parasite growth factors such as culture medium or incubation conditions were explored. A subsequent degree of variation was evidenced related to the parasite strain used and the culture conditions. The culture inhibition and the merozoite reinvasion inhibition assays were performed using a collection of plasma from premunized individuals living in two different endemic area of transmission in Senegal. High levels of inhibition were evidenced with a limited degree of variation according to the two different locations of individual's samples. A Significant relationship between anti-merozoite Ab levels and the culture inhibition assays was found contrary to the merozoite re-invasion inhibition assays. Taken together, our results show that such inhibition assays can be managed in facilities of southern laboratories near endemic areas. However, strictly defined culture conditions, homogeneous withdrawals of patients and standardized protocols are necessary for the assessment of such functional assaysas a potential markerof protection-associated mechanisms in longitudinal studies.