The Presence of Leukocytes inEx VivoAssays Significantly Increases the 50-Percent Inhibitory Concentrations of Artesunate and Chloroquine againstPlasmodium vivaxandPlasmodium falciparum
Kaewpongsri S., Sriprawat K., Suwanarusk R., Kyle DE., Lek-Uthai U., Leimanis M., Lwin KM., Phyo AP., Zwang J., Russell B., Nosten F., Renia L.
ABSTRACTPlasmodiumspeciesex vivosensitivity assay protocols differ in the requirement for leukocyte removal before culturing. This study shows that the presence of leukocytes significantly increases the 50% inhibitory concentration (IC50) ofP. vivaxandP. falciparumto artesunate and chloroquine relative to results with the paired leukocyte-free treatment. Although leukocyte removal is not an essential requirement for the conduct ofex vivoassays, its use has important implications for the interpretation of temporal and spatial antimalarial sensitivity data.