RESUMO
The efficiency of the immune system has been shaped throughout the evolutionary process allowing adaptations. In a Plasmodium vivax infection, the host attempts to develop an innate immune response to keep in check the parasite that is associated with inflammatory and regulatory processes. Production of pro-inflammatory and regulatory cytokines simultaneously appears to be a balancing mechanism for the host to prevent the onset of severe disease. Changes in the dynamics of circulating cytokines production can influence the pathogenesis, severity of the disease and episodes of recurrent Plasmodium vivax malaria (Pv-malaria). A cross-sectional study was conducted in endemic areas for Pv-malaria in the Amazonas State, Brazil. Several SNPs in TLR genes were genotyped by PCR-RFLP in 137 patients infected with P. vivax. Circulating cytokines IL-6, TNF, IL-2, IL-10, IFN-γ and IL-4 were measured by CBA. Influence of the studied SNPs on circulating cytokines was investigated by applying the Kruskal-Wallis test followed by Dunns' multiple comparison post-test. A Spearman correlation test also was performed to elaborate circulating cytokine networks and to demonstrate the level of interaction between each molecule. Individuals with genotypes A/G (TLR4 A299G), C/C (TLR6 S249P) and T/T (TLR9 -1486C/T) appear to produce less/gain IL-6, IFN-γ, IL-10, IL-2 and IL-4 compared to patients with wild-type and heterozygous genotypes. In addition, these genotypes seem to influence the interaction network between the molecules studied, causing a lower interaction, absence or even negative interaction between the cytokines. Data presented in this study suggests the influence of polymorphisms TLR4 (A299G), TLR6 (S249P) and TLR9 (-1486C/T) on the production of circulating cytokines during Pv-malaria.
Assuntos
Citocinas/sangue , Malária Vivax/sangue , Malária Vivax/genética , Plasmodium vivax/parasitologia , Polimorfismo de Nucleotídeo Único/genética , Receptores Toll-Like/genética , Adulto , Brasil , Estudos Transversais , Feminino , Genótipo , Humanos , Malária Vivax/virologia , Masculino , Polimorfismo de Fragmento de Restrição/genéticaRESUMO
Se evaluó la presencia de infecciones maláricas en individuos asintomáticos en la población Jivi de Puente Parhueña. El estudio fue de tipo prospectivo en tres momentos. El diagnóstico parasitológico se realizó mediante el examen convencional de gota gruesa y extendido (GGE) y la reacción en cadena de la polimerasa (PCR). El diagnóstico por microscopia indicó 2% (5/261) de láminas positivas en Abril, 1% (3/274) en Septiembre y 4% (5/135) en Diciembre. La PCR para Plasmodium spp., fue 46% (26/57) en abril, 49% (28/57) en Septiembre y 35% (20/57) en Diciembre. En los tres momentos predominó la presencia de P. vivax. La prueba de ELISA demostró 72% (41/57) seroreactivos en Abril, 53% (30/57) en Septiembre y 60% (34/57) en Diciembre. En Puente Parhueña habitan individuos con infecciones maláricas asintomáticos, con persistencia de anticuerpos antimalaricos, que probablemente representan un reservorio de gametocitos dentro de la comunidad.
The study was carried out to determine the present malaria infection in the asymptomatic Jivi people of Puente Parhueña. The study was prospective over three periods of time. The parasitological diagnoses were from thick and thin blood smears (GGE) and polymerase chain reaction (PCR). The antibody search was performed by ELISA. Microscopy of the slides detected the following positive results: 2% (2/261) April, 1% (3/274) September and 4% (5/135) December. Detection of Plasmodium by PCR was 46% (26/57) in April, 49% (28/57) in September y 35% (20/57) in December. Plasmodium vivax infected individuals predominated during these 3 times. Positives for ELISA were 72% (41/57) in April, 53% (30/57) September and 60% (34/57) December. The study demonstrated that people living in Puente Parhueña presented asymptomatic malaria infection with malaria antibodies persistence which likely represents a gametocyte potential reservoir for infection among the population.