Analysis of the lymphocyte cell population during malaria caused by Plasmodium vivax and its correlation with parasitaemia and thrombocytopaenia

• Published in: Malaria Journal
• Main Authors: Samantha Soares Ourives, Quessi Irias Borges, Diego Sampaio Arantes dos Santos, Eponina Cláudia Magalhães Melo, Rodrigo Medeiros de Souza, Amílcar Sabino Damazo
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2018
• Subjects: Plasmodium vivax; Parasitaemia; Platelets; Th1 cells; Th2 cells; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-018-2443-x; https://doaj.org/article/8139098669fd4fcb96d9e4a5b4b008ac

Abstract Background The mechanisms of activation and regulation of T lymphocytes and their cytokines in malaria caused by Plasmodium vivax are complex and poorly understood. Previous data suggest that T cells balance protective immune responses with immune mediated pathology in malaria. This study investigates the lymphocytic profile of patients infected with P. vivax by identifying and quantifying the specific sub-populations of Th1, Th2, Th17 and Treg cells and observing the correlation between parasitaemia and the number of platelets. Methods A cross-sectional study was carried out in an endemic area of the state of Acre, Brazil. In order to obtain identification and quantification of lymphocyte sub-populations through flow cytometry, blood samples were collected from 50 individuals infected with P. vivax and 20 non-infected controls. To differentiate Th1 from Th2, the presence of cytokines IL-4 and TNF was examined by enzyme-linked immunosorbent assay. Utilizing the Mann–Whitney and Spearman coefficient tests, comparison and correlation analysis were rendered to test the parasitaemia and the number of platelets relationship. Results The data indicate that individuals infected with P. vivax present a significant reduction in Th1, Th2 and Th17 cell sub-populations when compared to the non-infected control group. A negative correlation exists between parasitaemia and platelet counts in individuals infected with P. vivax. There is no correlation of parasitaemia or thrombocytopaenia with any sub-population of T lymphocytes analysed. Interestingly, patients with serum Th1 cytokine profile present inversely proportional parasitaemia to the increase in the number of Th1, Th2, Th17 and Treg cells while patients with serum Th2 cytokine profile present directly proportional parasitaemia to the increase in number of Th1 and Th2 cells. Regarding the number of platelets, patients with serum Th1 cytokine profile show a correlation directly proportional to the Th17 sub-population. In contrast, platelet counts are directly ...