Análise dos linfócitos em pacientes com malária vivax e sua relação com a anexina-A1 e citocinas

Abstract

Malaria is the most prevalent parasitic disease in the world. In Brazil, malaria cases are concentrated in the states of the Legal Amazon, where Plasmodium vivax is responsible for over 80% of cases. The aim of this study was to investigate the expression of ANXA1 in CD4+, CD8+ and regulatory T cells (Treg) and quantification of cytokines in plasma of patients with vivax malaria. Thus, understanding the relationship between lymphocyte activation and release of immunoregulatory molecules may contribute to the understanding of the immune response during this parasitosis. Methods The plasmatic quantification of IL-2, IL-4, IL-10, IL-13, IL-17, IFN-γ, TGF-β1, TNF-α in patients infected with P. vivax and healthy controls were evaluated by enzyme-linked immunosorbent assays (ELISA). The determination of the expression of ANXA1 in CD4+, CD8+ and Treg cells from patients and healthy controls was determined by immunofluorescence staining. All results were related with the number of circulating parasites and the number of previous episodes of malaria. Results The plasma level of IL-4, IL-13, IL-17 and TGF-β1 decreased in all patients primoinfected with low and high parasitaemia. Since IL-10 increased plasma concentrations in infected with low parasitaemia and more than one previous episode of malaria (915.1 ± 119.6 pg/mL) compared to the control group (326.1 ± 40.1 pg/mL) also found a reduction of this cytokine in patients primoinfected with low and high parasitaemia (451.8 ± 37.7 pg/mL and 402.9 ± 99.9 pg/mL, respectively) when compared to individuals of low parasitaemia and more than one episode of malaria (915.1 ± 119.6 pg/mL). In quantifying the expression of ANXA1 observed a reduction of this protein in CD4+ and CD8+ in patients primoinfected with low and high parasitaemia, while Treg cells was increased in patients primoinfected with low parasitaemia (151.5 ± 4 6 A.U.) compared with patients with high parasitaemia and previous infection (103.3 ± 3.1 A.U.). Conclusion The ANXA1 is expressed differently in lymphocyte subtypes and may have a different action on lymphocyte proliferation. Furthermore, ANXA1 may be contributing to increased levels of IL-10 in plasma of these patients.