Abstract

Malaria infection triggers off vaso-occlusive attacks in sickle cell patients, leading drastically to death. Sickle-cell patients use artemisinin-based combination therapies (ACTs) as recommended by the WHO to treat malaria infections to prevent these crises. The survey of sensitivity of parasites collected from sickle-cell patients needs is important to be re-specified. Red cells from these patients differ from others in terms of redox potential and calcium flow. The aim of this study was to assess the in-vitro efficacy of standard antimalarials used by this fragile population in order to find out a suitable medical policy for them in Côte d'Ivoire. For this purpose, the standard isotope test for schizont maturation and the Ring-stage survival assay were used to ascertain the in-vitro sensitivity of 116 Plasmodium falciparum isolates from sickle cell patients, collected from Abidjan for dihydroartemisinin, chloroquine, amodiaquine, quinine and luméfantrine. All the isolates exhibited different responses with the different antimalarials. No cases of in-vitro resistance to Lumefantrine and Quinine were noticed, reappearance of chloroquine-sensitive and a strong cross activity of chloroquine and dihydroartemisinin were observed. Indeed, 87 (65.41%) isolates were dihydroartemisinin-sensitive in-vitro whereas 20 (15.04%) had a resistants after exposure to 700 nM. The majority of clinical isolates non-responding to dihydroartemisinin were from the sickle cell phenotype HbSS. To sum up, despite the decrease of the in-vitro sensitivity of dihydroartemisinin on some sickle cell isolates, this molecule is still efficient. However, it must be actively monitored by the National Malaria Control Programme, particularly for sickle cell patients where a decrease in sensitivity was observed.

Key words: Sickle cell anemia, malaria, Côte d’Ivoire, Plasmodium falciparum, anti-malarials, treatment resistance, in-vitro drug monitoring.