Platelet-induced autoagglutination of Plasmodium falciparum-infected red blood cells and disease severity in Thailand

The relationship of the platelet-mediated autoagglutination of Plasmodium falciparum-infected red blood cells (IRBCs) to disease severity was investigated in 182 Thai patients with falciparum malaria; it was evident in 43% of uncomplicated malaria (n = 63), 41% of severe malaria (n = 104), and 100% of cerebral malaria (n = 15; P = .001) isolates. The median (range) number of IRBCs in agglutinates per 1000 IRBCs was significantly higher in cerebral malaria (6 [ 3-42]) than in severe (0 [0-52]) and uncomplicated (0 [0-24]) malaria (P = .01). In multivariate analyses, high parasitemia and cerebral malaria were associated independently with parasite agglutination.