Impairment of Invasion and Maturation and Decreased Selectivity of Plasmodium falciparum in G6PD Viangchan and Mahidol Variants.

Abstract

Protection against Plasmodium falciparum is observed in a population deficient in glucose-6-phosphate dehydrogenase (G6PD), particularly in African and Mediterranean regions. However, such protection remains unknown among G6PD-deficient individuals in Southeast Asia. In this study, we assessed the invasion and maturation of P falciparum K1 in a culture of erythrocytes isolated from Thai subjects carrying Viangchan (871G > A) and Mahidol (487G > A). We found that the parasites lost their ability to invade hemizygous and homozygous G6PD-deficient erythrocytes of Viangchan and Mahidol variants in the second and third cycles of intraerythrocytic development. It is interesting to note that P falciparum parasites selectively grew in erythrocytes from hemi- and homozygous genotypes with normal G6PD activity. Moreover, externalization of phosphatidylserine upon P falciparum infection was significantly increased only in Viangchan hemizygous variant cells. This study is the first to show that blockage of invasion in long-term culture and potentially enhanced removal of parasitized erythrocytes were observed for the first time in erythrocytes from Viangchan and Mahidol G6PD-deficient individuals.