Circulating endothelial cells in severe Plasmodium falciparum infection

Plasmodium falciparum infection is associated with diffuse vascular dys-regulation. Levels of blood circulating endothelial cells (CECs; CD146^{+}CD45^{-}) are a marker of vascular injury. This study aimed to measure blood CECs by flow cytometery in patients with acute malaria infection before and after treatment and to evaluate the prognostic value of that measurement for that disease. The subjects were allocated into: Group I: uncomplicated malaria (UM, n = 32), Group II: severe malaria (SM, n = 12), Group III: the treated UM (TUM, n = 32), Group IV: the treated SM (TSM, n = 12) and Group V: healthy controls (HC, n = 25). Before treatment, SM patients showed the highest mean number of CECs (30,658.3 ± 2658.2/5 × 10^{6} peripheral blood mononuclear cells (PBMCs)), followed by UM patients (19,481.56 ± 866.83/5×10^{6}PBMCs) and both groups were significantly higher than HC (2034 ± 300.59/5×10^{6}PBMCs, P < .001). The level of CECs decreased significantly in both infected groups after treatment; in TUM it became 5602.18 ± 509.72/5 × 10^{6}PBMCs and in TSM it reached 8457.5 ± 452.4/5 × 10^{6} PBMCs (both values P < .001 in comparison with SM). By receiver operating characteristic curve analysis, the best cut-off count for CECs which enables prediction of the occurrence of severe malaria infection was 27,150/5 × 10^{6} PBMCs or more, with 100% sensitivity, 100% specificity, and 100% accuracy. CECs had a significant positive correlation with parasitemia index and serum creatinine and a significant negative correlation with hemoglobin concentration in patients with acute malaria. In conclusion, the level of CECs could be used as a biomarker denoting endothelium damage during acute P. falciparum infection, and it correlated with infection severity and predicted its prognosis.