What is the molecular basis of platelet-mediated clumping?
Platelet-mediated clumping of infected erythrocytes is a parasite adhesion phenotype that is distinct from rosetting and has previously been associated with severe malaria in different parts of the world (Kenya: Pain et al, PNAS 2001, Thailand: Chotivanich et al, J Infect Dis 2004). However, in a recent study in Mali we found that clumping was primarily associated with high parasitaemia rather than severe clinical symptoms (Arman et al, 2007). We have also discovered that the assay for clumping is highly influenced by the precise conditions used (haematocrit and parasitaemia both greatly influence outcome) (Arman et al, in preparation), and we suggest that previous disease-association studies may not have been done under optimal conditions, therefore the association between clumping and severe malaria requires further investigation. The molecular basis of clumping is currently unclear, although human platelet CD36 is known to be essential. We are currently investigating the role of var
