title: The deformability of red blood cells parasitized by Plasmodium falciparum and P. vivax.
abstract: Red blood cells (RBCs) must deform considerably during their multiple passages through the microvasculature and the sinusoids of the spleen. RBCs infected with Plasmodium falciparum (Pf-IRBCs) become increasingly rigid as they mature but avoid splenic clearance by sequestering in venules and capillaries. In contrast, RBCs infected with P. vivax (Pv-IRBCs) do not sequester. We compared the effects of P. vivax and P. falciparum infection on RBC deformability in a laminar shear flow system. Pf-IRBCs became more rigid as the parasite matured, but equivalent maturation of Pv-IRBCs resulted in a doubling of flexibility. Coincidentally, the IRBC surface area increased from 56.7+/-1.3 microm2 to 74.7+/-0.6 microm2 to 90.9+/-1.1 microm2 in ring-, trophozoite-, and schizont-stage Pv-IRBCs, respectively, whereas Pf-IRBCs did not increase in size. P. vivax increases the deformability of IRBCs and thereby avoids splenic entrapment.
authors.affiliation: Department of Parasitology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
authors.forename: Rossarin
authors.initials: R
authors.lastname: Suwanarusk
authors.forename: Brian M
authors.initials: BM
authors.lastname: Cooke
authors.forename: Arjen M
authors.initials: AM
authors.lastname: Dondorp
authors.forename: Kamolrat
authors.initials: K
authors.lastname: Silamut
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: White
authors.forename: Rachanee
authors.initials: R
authors.lastname: Udomsangpetch
mesh_terms: D000818:Animals; D004907:Erythrocyte Deformability; D004912:Erythrocytes / Q000469:parasitology*; D006801:Humans; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D010966:Plasmodium vivax / Q000472:pathogenicity*