Rossarin SuwanaruskBrian M. CookeArjen M. DondorpKamolrat SilamutJetsumon SattabongkotNicholas J. WhiteRachanee UdomsangpetchFaculty of Medical TechnologyMahidol UniversityArmed Forces Research Institute of Medical Sciences, ThailandMonash UniversityNuffield Department of Clinical Medicine2018-07-242018-07-242004-01-15Journal of Infectious Diseases. Vol.189, No.2 (2004), 190-194002218992-s2.0-0742324945https://repository.li.mahidol.ac.th/handle/20.500.14594/21409Red 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 μm2to 74.7 ± 0.6 μm2to 90.9 ±1.1 μm2in 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.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1086/380468