Binding to CSA receptor is associated with asymptomatic and mild malaria: a preliminary study using P.falciparum field isolates from Sudan

Abstract

Malaria imposes great socio-economic burden on humanity, and afflicts approximately 90 countries and territories in the tropical and subtropical regions, almost one half of them are in Africa, South of Sahara. Sequestration of parasitized erythrocytes within the small vessels of vital organs is a key event in the pathogenesis of malaria and responsible of virulence of Plasmodium falciparum parasite. To find out whether the ability of infected red blood cells (IRBCs) to adhere to a specific receptor is a risk factor for developing severe clinical manifestation of the disease, in-vitro cytoadhesion and inhibition experiments were performed on field isolates obtained from five symptomatic and five asymptomatic patients inhabiting Gazira State, Central Sudan. The results showed significant lower levels (p<0.02) of cytoadhesion among asymptomatic compared to symptomatic patients. Percent inhibition by FA6-152, a monoclonal antibody for CD36, was comparable between the two study groups. However, the inhibition by CSA protein was less among symptomatic compared to asymptomatic patients. These results shed light on possible role of CSA receptors expressed on endothelial cells in ameliorating the events associated with the severe phenotype of the disease.