Suwanarusk Rossarin, Cooke Brian M, Dondorp Arjen M, Silamut Kamolrat, Sattabongkot Jetsumon, White Nicholas J, Udomsangpetch Rachanee
Department of Parasitology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
J Infect Dis. 2004 Jan 15;189(2):190-4. doi: 10.1086/380468. Epub 2004 Jan 5.
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.
红细胞（RBCs）在多次通过微脉管系统和脾脏血窦的过程中必须发生显著变形。感染恶性疟原虫（Pf-IRBCs）的红细胞在成熟过程中会变得越来越僵硬，但通过在小静脉和毛细血管中滞留来避免被脾脏清除。相比之下，感染间日疟原虫（Pv-IRBCs）的红细胞不会滞留。我们在层流剪切流系统中比较了间日疟原虫和恶性疟原虫感染对红细胞变形性的影响。随着寄生虫成熟，Pf-IRBCs变得更加僵硬，但Pv-IRBCs同等程度的成熟却导致其柔韧性增加了一倍。巧合的是，在环状体、滋养体和裂殖体阶段的Pv-IRBCs中，被感染红细胞的表面积分别从56.7±1.3平方微米增加到74.7±0.6平方微米，再增加到90.9±1.1平方微米，而Pf-IRBCs的大小没有增加。间日疟原虫增加了被感染红细胞的变形性，从而避免被脾脏截留。
