NCR3 polymorphism, haematological parameters, and severe malaria in Senegalese patients.

Alassane Thiam,Sandrine Marquet,Samia Nisar,Sabrina Baaklini,Mouhamadou Mansour Fall,Magali Torres,Michel Sanka,Babacar Mbengue,Pascal Rihet,Maryam Diarra,Fatou Thiam,Rokhaya Ndiaye Diallo,Alioune Dieye

doi:10.7717/peerj.6048

Abstract

BackgroundHost factors, including host genetic variation, have been shown to influence the outcome of Plasmodium falciparum infection. Genome-wide linkage studies have mapped mild malaria resistance genes on chromosome 6p21, whereas NCR3-412 polymorphism (rs2736191) lying within this region was found to be associated with mild malaria.MethodsBlood samples were taken from 188 Plasmodium falciparum malaria patients (76 mild malaria patients, 85 cerebral malaria patients, and 27 severe non-cerebral malaria patients). NCR3-412 (rs2736191) was analysed by sequencing, and haematological parameters were measured. Finally, their association with clinical phenotypes was assessed.ResultsWe evidenced an association of thrombocytopenia with both cerebral malaria and severe non-cerebral malaria, and of an association of high leukocyte count with cerebral malaria. Additionally, we found no association of NCR3-412 with either cerebral malaria, severe non-cerebral malaria, or severe malaria after grouping cerebral malaria and severe non-cerebral malaria patients.ConclusionsOur results suggest that NCR3 genetic variation has no effect, or only a small effect on the occurrence of severe malaria, although it has been strongly associated with mild malaria. We discuss the biological meaning of these results. Besides, we confirmed the association of thrombocytopenia and high leukocyte count with severe malaria phenotypes.

Highlights

Host factors, including host genetic variation, have been shown to influence the outcome of Plasmodium falciparum infection
We report the analysis of NCR3-412 and several haematological parameters association with severe malaria phenotypes
We found a reduction of platelet count in non CM (NCM) patients compared to the ones of mild malaria (MM) patients (P = 0.018), whereas there was no difference for the leucocyte count (P = 0.44) between these two groups

Summary

Introduction

Host factors, including host genetic variation, have been shown to influence the outcome of Plasmodium falciparum infection. NCR3-412 (rs2736191) was analysed by sequencing, and haematological parameters were measured Their association with clinical phenotypes was assessed. Our results suggest that NCR3 genetic variation has no effect, or only a small effect on the occurrence of severe malaria, it has been strongly associated with mild malaria. We confirmed the association of thrombocytopenia and high leukocyte count with severe malaria phenotypes. NCR3 polymorphism, haematological parameters, and severe malaria in Senegalese patients. According to the WHO report, the major complications account for 429,000 deaths annually, essentially in children, pregnant woman and immuno-suppressed individuals It should be noticed, that approximately 2% of the clinical cases are severe (Greenwood, 1997), while most of malarial infection cases remain asymptomatic

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Conclusion