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

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

doi:10.7717/peerj.6048

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

PeerJ. 2018 Dec 3:6:e6048. doi: 10.7717/peerj.6048. eCollection 2018.

Authors

Affiliations

¹ Unité d'Immunogénétique, Institut Pasteur de Dakar, Dakar, Senegal.
² Aix Marseille Univ, INSERM, TAGC, Marseille, France.
³ Service d'Immunologie, University Cheikh Anta Diop of Dakar, Dakar, Senegal.
⁴ G4 Biostatistique, Institut Pasteur de Dakar, Dakar, Sénégal.
⁵ Service de Réanimation, Hôpital Principal de Dakar, Dakar, Senegal.

Abstract

Background: Host 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.

Methods: Blood 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.

Results: We 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.

Conclusions: Our 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.

Keywords: Genetic association; Host factors; Mild malaria; Plasmodium falciparum; Severe malaria.

Grants and funding

This work was supported by the management of the Institute Pasteur of Dakar, the Directorate of International Affairs of the Institute Pasteur in Paris, the Department of Cultural Action of the French Embassy in Senegal, INSERM, and the university of Aix-Marseille. S Baaklini, M Sanka, and S Nisar were supported by a PhD fellowship from the French ministry, PACA regional council, and the Higher Education Commission (HEC) from Pakistan, respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.