Perfil de citocinas de indivíduos infectados pelo Schistosoma mansoni residentes em área endêmica.

Abstract

Schistosomiasis is a disease caused by the parasite Schistosoma mansoni, is associated with tropical climate and waterborne, and has a high incidence rate in emerging countries such as Brazil. The infection leads to the development of several clinical manifestations and the severity of the disease is a consequence of the fibrosis caused by the granulomatous reaction around the eggs deposited in the hepatic portal system. Factors or mechanisms responsible for the development of these clinical manifestations and morbidity are not yet fully understood, however, it is known that the immune response plays an important role. The present study aimed to evaluate the cytokine profile of S. mansoni infected individuals residing in the endemic area and to analyze the influence of variables such as age, sex, parasitic load, changes in periportal echogenicity and expression of SmATPDases in the immunological response of these individuals. The study involved 64 infected and 33 uninfected individuals, with 19 residents and 14 not residing in an area endemic to the disease. All participants completed the sociodemographic questionnaire; performed the parasitological examination of feces, clinical examination and abdominal ultrasonography; and participated in the collection of blood. The parasite eggs were obtained for the determination of SmATPDases expression by qPCR. Cytokine levels were measured by flow cytometry and statistical analyzes were performed using Prism 5.0. The study demonstrated that individuals infected with S. mansoni produced higher IL-4, IL-10 and lower levels of IL-2 than uninfected individuals. Age, parasite load, SmATPDase 2 expression and hyperechogenicity were shown to be relevant factors in the immune response of infected individuals. Infected individuals who were between 0 and 19 years old had higher IL-4 levels when compared to those aged 20 to 59 years. Infected individuals who had high parasite load (> 100 opg) produced higher levels of IL-10 when compared to individuals who had low parasitic load (<50 opg). In addition, individuals with extremely high parasite load (> 300 opg) had higher TNF and IL-10 levels compared to individuals with extremely low parasite load (<5 opg). Infected individuals who expressed only the SmATPDase 2 enzyme in their stool samples produced higher IL-6 levels when compared to the individuals expressing both enzymes (SmATPDase 1 and 2). Hyperechogenicity also presented as an interfering factor in the immune response, since individuals with altered periportal echogenicity produced higher levels of IL-10 and TNF and lower levels of IL-17. Taken together, these results suggest that the immune response of individuals infected with Schistosoma mansoni may contribute to disease morbidity, since increased parasitic load and changes in periportalXI echogenicity are associated with increased levels of IL-10 and TNF, cytokines associated with the development of fibrosis. In addition, it is important to note that factors associated with the individual, such as age, as well as factors related to the parasite, such as the expression of ectonucleotidases, may alter the individual's immune response during infection.