Platelet-mediated clumping of Plasmodium falciparum infected erythrocytes is associated with high parasitemia but not severe clinical manifestations of malaria in African children.

Platelet-mediated clumping of Plasmodium falciparum-infected erythrocytes is an adhesive phenotype commonly found in field isolates that has previously been associated with severe malaria. Here, clumping was assessed in 131 isolates from Malian children. The clumping phenotype was seen in 6% (N = 51) of uncomplicated malaria, 24% (N = 51) of severe malaria, and 45% (N = 29) of high parasitemia non-severe malaria isolates. Multivariate analysis indicated that clumping was strongly positively associated with parasitemia (F(1,122) = 24.1, P < 0.001) but not with disease category (F(2,122) = 1.8, P = 0.17). Therefore platelet-mediated clumping in Malian P. falciparum isolates is primarily associated with high parasitemia and not with severe clinical manifestations of malaria.