Asymptomatic carriage of Plasmodium falciparum in children living in a hyperendemic area occurs independently of IgG responses but is associated with a balanced inflammatory cytokine ratio.

Autor: Fogang B; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Department of Animal Biology and Physiology of the University of Yaoundé I, BP 812, Yaounde, Cameroon., Schoenhals M; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Maloba FM; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Biabi MF; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Department of Biochemistry, University of Douala, BP 24157, Douala, Cameroon., Essangui E; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Donkeu C; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Department of Animal Biology and Physiology of the University of Yaoundé I, BP 812, Yaounde, Cameroon., Cheteug G; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Department of Medical Laboratory Sciences, University of Buea, BP 63, Buea, Cameroon., Kapen M; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Keumoe R; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Kemleu S; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Nsango S; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Faculty of Medicine and Pharmaceutical Sciences, University of Douala, BP 2701, Douala, Cameroon., Cornwall DH; Department of Pathology, University of Utah, 15 N Medical Drive, Salt Lake City, 84112, USA., Eboumbou C; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon.; Faculty of Medicine and Pharmaceutical Sciences, University of Douala, BP 2701, Douala, Cameroon., Perraut R; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon., Megnekou R; Department of Animal Biology and Physiology of the University of Yaoundé I, BP 812, Yaounde, Cameroon., Lamb TJ; Department of Pathology, University of Utah, 15 N Medical Drive, Salt Lake City, 84112, USA. tracey.lamb@path.utah.edu., Ayong LS; Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274, Yaounde, Cameroon. layong05@yahoo.co.uk.
Jazyk: angličtina
Zdroj: Malaria journal [Malar J] 2024 Sep 04; Vol. 23 (1), pp. 268. Date of Electronic Publication: 2024 Sep 04.
DOI: 10.1186/s12936-024-05086-8
Abstrakt: Background: Asymptomatic carriage of infected red blood cells (iRBCs) can be prevalent in communities regardless of transmission patterns and can occur with infection of different Plasmodium species. Clinical immunity dampens the inflammatory responses leading to disease symptoms in malaria. The aim of this study was to define the immunological correlates of asymptomatic carriage of Plasmodium falciparum in a highly exposed population.
Methods: 142 asymptomatic Plasmodium-infected individuals greater than 2 years of age without fever (body temperature <37.5 ℃) were followed weekly for 10 weeks before being treated with artemisinin-based combination therapy (ACT). Plasma levels of 38 cytokines were measured at baseline by Luminex and the quantity and growth inhibitory activities of circulating parasite-reactive antibodies measured. The Plasmodium antigen tested included P. falciparum merozoite extract (ME) and schizont extract (SE), and the recombinant proteins erythrocyte binding antigen 175 (EBA-175) and merozoite surface protein 1 (MSP-1 19 ).
Results: Median levels of IgG against P. falciparum EBA-175 and MSP-1 19 at baseline were significantly higher in those older than 20 years of age compared with the younger age group and appeared to correlate with better parasite control. Amongst all participants there were no discernible changes in IgG levels over time. Parasite density was higher in the younger age group and associated with IL-10, TNF and MCP-1 levels. A balanced IL-10:TNF ratio was associated with asymptomatic malaria regardless of age, and balanced ratios of IL-10/TNF and IL-10/IFN-γ were the only significant correlate of maintenance of asymptomatic malaria over the course of the study in individuals 20 years of age and younger.
Conclusion: The above findings indicate that asymptomatic carriage of P. falciparum in children living in a hyperendemic area occurs independently of IgG but is associated with a balanced inflammatory cytokine ratio.
(© 2024. The Author(s).)
Databáze: MEDLINE
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