Respiratory and functional tests in the assessment and prognosis of patients with chagas disease

Chagas disease causes an important impact on cardiorespiratory system, functional and working capacity of the patient. Performing a functional assessment on these individuals becomes essential, since the impact of physical limitation is an important factor that is related with other life domains, such as risk of cardiovascular events in a brief period and risk of death. The goal of this work was to perform a literature review to present the evaluative and prognostic value of main valid respiratory and functional tests in patients with Chagas disease, as well as their applicability and reproducibility. A literature search was performed from 1981 to 2020 in Scielo, Pubmed/Medline, Science Direct, Scopus and Web of Science databases. Only complete studies published in English, Portuguese or Spanish were analyzed which specifically discussed the respiratory and functional tests used in patients with Chagas disease. In total, 544 articles were retrieved of which 35 were eligible. The main functional tests approached were Cardiopulmonary Exercise Testing, Incremental Exercise Testing and Six-Minute Walk Test. Several studies show themselves as useful markers for predicting quality of life, mortality and functional impairment, in addition to other patients' characteristics. Several tests can be used to assess the respiratory and functional impact to patients' health, as well as its relationship with important domains of their lives

NOD2 receptor is crucial for protecting against the digestive form of Chagas disease.

Digestive and cardiodigestive forms of Chagas' disease are observed in 2% to 27% of the patients, depending on their geographic location, Trypanosoma cruzi strain and immunopathological responses. The aim of this work was to evaluate the role of NOD2 innate immune receptor in the pathogenesis of the digestive system in Chagas' disease. Patients with digestive form of the disease showed lower mRNA expression of NOD2, higher expression of RIP2 and α-defensin 6, compared to indeterminate form, detected by Real-time PCR in peripheral blood mononuclear cells. In addition, there was a negative correlation between the expression of NOD2 and the degree of dilation of the esophagus, sigmoid and rectum in those patients. The infection of NOD2-/- mice with T. cruzi strain isolated from the digestive patient induced a decrease in intestinal motility. Histopathological analysis of the colon and jejunum of NOD2-/- and wild type C57BL/6 animals revealed discrete inflammatory foci during the acute phase of infection. Interestingly, during the chronic phase of the infection there was inflammation and hypertrophy of the longitudinal and circular muscular layer more pronounced in the colon and jejunum from NOD2-/- animals, when compared to wild type C57BL/6 mice. Together, our results suggest that NOD2 plays a protective role against the development of digestive form of Chagas' disease.