Surasak wanram. Study of endothelial cell and red blood cell interaction in Plasmmodium falciparum infection a comparative study between normal and thalassemia . Master's Degree(Clinical Pathology). Mahidol University. : Mahidol University, 2003.
Study of endothelial cell and red blood cell interaction in Plasmmodium falciparum infection a comparative study between normal and thalassemia
Abstract:
Thalassemia, the hereditary hemolytic disorder caused by a partial or complete
deficiency in α- or β-globin chain synthesis, is widely believed to provide protection
against malaria. Although the mechanism for this protection is not known, it may
involve cytoadherence, a factor in the pathogenesis of P. falciparum malaria infection.
In this investigation, we have carried out a comparative study of the binding of
normal (n = 25) and various types of thalassemic red blood cells (RBCs), including α-
thalassemia 1 trait (α-thal 1 trait; n = 6), α-thalassemia 2 trait (α-thal 2 trait; n = 9), β-
thalassemia trait (β-thal trait; n = 20), heterozygous Hb E (Hb E trait; n = 27) and
heterozygous Hb Constant Spring (Hb CS trait; n = 9) with and without parasitization
by P. falciparum (K1 strain) to vascular endothelial cells (ECV304) in vitro. We have
found that the adhesion of non-parasitized heterozygous thalassemic RBCs (all
genotypes) to endothelial cells (ECs) was increased significantly more than that to
normal cells (P < 0.01). After parasitization by P. falciparum, the number of normal
RBCs bound to ECs was significantly increased compared with that of non-infected
RBCs (P < 0.01) whereas in heterozygous thalassemic RBCs parasitized by P.
falciparum, there was no significant difference as compared with non-parasitized
RBCs (P > 0.05). When normal and thalassemic RBCs in parasitized conditions were
compared, the number of RBCs bound to ECs similarly showed no significant
difference (P > 0.05). For comparison, the number of ECs with bound RBCs was
enumerated and the results obtained were similar to that of bound RBCs.
In a flow cytometric binding assay, we observed a predominance of ICAM-1 over
PECAM-1, CD36 and E-selectin on ECs when normal non-infected and infected
conditions were compared. In addition, using flow cytometric determination, we also
studied RBC membrane alterations in non-parasitized and parasitized conditions by
detecting phosphatidylserine (PS) exposure using annexin V and hydroethidine. An
increased level of PS was found in all types of non-parasitized thalassemic RBCs as
compared with normal control (P < 0.05), while P. falciparum-infected normal and
thalassemic RBCs did not show any significant differences (P > 0.05)