1 56 u03bcg ml of total igg fig2 b and fig2 c rectangles in bold importantly the pfemp1 antibodies also showed surface reactivity with heterologous rosetting strains this was especially marked between the igm binding rosetting strains hb3r tm284 and it par and their antibodies to variants hb3var6 tm284var1 and itvar60 respectively with surface reactivity at lt 10 u03bcg ml for heterologous antibody parasite combinations fig2 c the non igm binding rosetting strains muz12 tm180 and it r29 were also recognised by antibodies to igm binding rosetting variants although higher concentrations were required 100 400 u03bcg ml of total igg fig2 c although these concentrations are high they still represent a considerable dilution of whole serum equivalent to 1 100 to 1 25 dilution therefore they are potentially achievable in vivo the antibodies against rosetting pfemp1 variants did not recognise parasites selected for other adhesion phenotypes fig2 c including binding to cd36 or icam 1 parasites expressing group b and c var genes or binding to brain endothelial cells parasites expressing an alternative sub set of group a and b a var genes thus only parasites with a shared adhesion phenotype share epitopes that are recognised by cross reactive antibodies to pfemp1 surface recognition of live infected erythrocytes by antibodies in vivo is likely to lead to parasite clearance via effector mechanisms.