Phospholipides plasmatiques et de la membrane érythrocytaire chez les enfants atteints de paludisme à Plasmodium falciparum

Abstract

Plasmodium falciparum infection modifies the distribution of phospholipids on both sides of the erythrocyte-plasma membrane. We sought to understand the action of the parasite on both plasma and membrane phospholipids and their relation to parasite counts in the blood. We conducted this study from 1 February through 30 June 2007 in the Malaria Clinical Research Unit of the Libreville General Hospital Centre, measuring phospholipids in plasma and erythrocyte membranes of children affected by P. falciparum malaria and assessing their relation to blood parasites, lactates and hemoglobin. The study included 60 children. The mean blood parasite count was 1.07 x 105 per ml. Mean plasma phospholipids were 2.6+/-0.9 mmol/l and lactates 4.7+/-3.7 mmol/l. At the membrane level, we found 2.8+/-1.2 mmol/l of phospholipids per 106 red blood cells. Phospholipids in these two compartments were positively correlated with one another (r=0.392; p=0.023). Plasma phospholipids were also correlated positively with hemoglobin (r=0.36; p=0.032) and negatively with the number of parasites (r=0.442; p=0.002). The latter, in turn, was positively correlated with lactates (r=0.527; p=0.022) and negatively with membrane phospholipids (r=0.542; p=0.006). The mean hemoglobin level (8.9 g/dl) suggests permanent blood loss in these children, although they may be considered new malaria patients. The relations revealed here between membrane phospholipids, blood parasite counts, and lactate levels are due to the increased energy needs of erythrocytes, but also to the need to synthesize substances intended for cellular defense. P. falciparum thus leads to a decrease in plasma phospholipids, which could be estimated and correlated with blood parasites in a study with a wider range of parasite counts.