Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): A study protocol for a randomized clinical trial

BackgroundChagas disease (CD) is a neglected endemic disease with worldwide impact due to migration. Approximately 50–70% of individuals in the chronic phase of CD present the indeterminate form, characterized by parasitological and/or serological evidence of Trypanosoma cruzi infection, but without clinical signs and symptoms. Subclinical abnormalities have been reported in indeterminate form of CD, including pro-inflammatory states and alterations in cardiac function, biomarkers and autonomic modulation. Moreover, individuals with CD are usually impacted on their personal and professional life, making social insertion difficult and impacting their mental health and quality of life (QoL). Physical exercise has been acknowledged as an important strategy to prevent and control numerous chronic-degenerative diseases, but unexplored in individuals with the indeterminate form of CD. The PEDI-CHAGAS study (which stands for “Home-Based Exercise Program in the Indeterminate Form of Chagas Disease” in Portuguese) aims to evaluate the effects of a home-based exercise program on physical and mental health outcomes in individuals with indeterminate form of CD.Methods and designThe PEDI-CHAGAS is a two-arm (exercise and control) phase 3 superiority randomized clinical trial including patients with indeterminate form of CD. The exclusion criteria are <18 years old, evidence of non-Chagasic cardiomyopathy, musculoskeletal or cognitive limitations that preclude the realization of exercise protocol, clinical contraindication for regular exercise, and regular physical exercise (≥1 × per week). Participants will be assessed at baseline, and after three and 6 months of follow-up. The primary outcome will be QoL. Secondary outcomes will include blood pressure, physical fitness components, nutritional status, fatigability, autonomic modulation, cardiac morphology and function, low back pain, depression and anxiety, stress, sleep quality, medication use and adherence, and biochemical, inflammatory and cardiac biomarkers. Participants in the intervention group will undergo a home-based exercise program whilst those in the control group will receive only general information regarding the benefits of physical activity. Both groups will receive the same general nutritional counseling consisting of general orientations about healthy diets.ConclusionThe findings from the present study may support public health intervention strategies to improve physical and mental health parameters to be implemented more effectively in this population.Clinical trial registration[https://ensaiosclinicos.gov.br/rg/RBR-10yxgcr9/], identifier [U1111-1263-0153]

O-glycosylation in cell wall proteins in Scedosporium prolificans is critical for phagocytosis and inflammatory cytokines production by macrophages.

In this study, we analyze the importance of O-linked oligosaccharides present in peptidorhamnomannan (PRM) from the cell wall of the fungus Scedosporium prolificans for recognition and phagocytosis of conidia by macrophages. Adding PRM led to a dose-dependent inhibition of conidia phagocytosis, whereas de-O-glycosylated PRM did not show any effect. PRM induced the release of macrophage-derived antimicrobial compounds. However, O-linked oligosaccharides do not appear to be required for such induction. The effect of PRM on conidia-induced macrophage killing was examined using latex beads coated with PRM or de-O-glycosylated PRM. A decrease in macrophage viability similar to that caused by conidia was detected. However, macrophage killing was unaffected when beads coated with de-O-glycosylated PRM were used, indicating the toxic effect of O-linked oligosaccharides on macrophages. In addition, PRM triggered TNF-α release by macrophages. Chemical removal of O-linked oligosaccharides from PRM abolished cytokine induction, suggesting that the O-linked oligosaccharidic chains are important moieties involved in inflammatory responses through the induction of TNF-α secretion. In summary, we show that O-glycosylation plays a role in the recognition and uptake of S. prolificans by macrophages, killing of macrophages and production of pro- inflammatory cytokines

Effect of <i>O</i>-glycosylation on the release of nitric oxide (NO).

<p><i>S</i>. <i>prolificans</i> conidia and PRM led to a significant increase in the levels of NO during interaction with macrophages. <i>O</i>-linked oligosaccharides structures were not required for such induction, as observed in the graphs. Values are the means of three independent experiments. Asterisks denote values significantly different from control (*** P < 0.001).</p

Cytokine release induced by conidia and PRM from <i>S</i>. <i>prolificans</i>.

<p>(<b>A</b>) <i>O</i>-linked oligosaccharidic chains are crucial to the production of TNF-α. Both <i>S</i>. <i>prolificans</i> conidia and PRM were able to stimulate the production of TNF-α. This effect was abolished when the <i>O</i>-linked oligosaccharides were removed from PRM molecules. (<b>B</b>). <i>S</i>. <i>prolificans</i> conidia were able to stimulate the production of IL-10, but this effect was independent of PRM. Values are the means of three independent experiments. Asterisks denote values significantly different from control (** P = 0.002; *** P < 0.001).</p

Evaluation of macrophages viability.

<p>(<b>A</b>) <i>S</i>. <i>prolificans</i> conidia cells are able to kill macrophages during the first hour of interaction. (<b>B</b>) Cytotoxicity of soluble PRM accessed by the neutral red dye-uptake method on macrophages during 24 h of incubation was measured by the absorbance measured at 490 nm in a spectrophotometer. (<b>C</b>) Beads coated with PRM and de-<i>O</i>-PRM showed that <i>O</i>-linked oligosaccharides are responsible for the toxic effects of PRM on macrophages. Values are the means of three independent experiments. Asterisks denote values significantly different from control (* P < 0.05; *** P < 0.001).</p

PRM is on the fungal cell surface.

<p>Immune serum was able to bind to <i>S</i>. <i>prolificans</i> conidial forms (<b>Aa and Ab</b>), but pre-incubation with soluble pRM was able to inhibit the binding between <i>S</i>. <i>prolificans</i> conidia cells and immune serum (<b>Ac and Ad</b>), as observed by immunofluorescence microcopy. A similar data was observed by flow cytometry showing that conidia fluorescence is practically abolished when serum is pre-treated with PRM (<b>B</b>). Bar: 10 μm.</p

Partial 2D HSQC NMR: NMR spectrum of the anomeric region from <i>N</i>-glycan of PRM (rhamnomannoprotein).

<p>Partial 2D HSQC NMR: NMR spectrum of the anomeric region from <i>N</i>-glycan of PRM (rhamnomannoprotein).</p

Phagocytosis inhibition assay between <i>S</i>. <i>prolificans</i> conidia and peritoneal macrophages by intact and de-<i>O-</i>glycosylated PRM.

<p>The macrophages were pre-treated or not (control) for 30 min with two different concentrations of intact and de-<i>O-</i>glycosylated PRM (12.5 and 25 μg/ml), before interacting with conidial cells for 1 h. The phagocytic index values represent the mean ± S.D. of three independent experiments performed in triplicate. Asterisks denote values significantly different from control (* P < 0.05).</p

Data_Sheet_4_Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): A study protocol for a randomized clinical trial.PDF

BackgroundChagas disease (CD) is a neglected endemic disease with worldwide impact due to migration. Approximately 50–70% of individuals in the chronic phase of CD present the indeterminate form, characterized by parasitological and/or serological evidence of Trypanosoma cruzi infection, but without clinical signs and symptoms. Subclinical abnormalities have been reported in indeterminate form of CD, including pro-inflammatory states and alterations in cardiac function, biomarkers and autonomic modulation. Moreover, individuals with CD are usually impacted on their personal and professional life, making social insertion difficult and impacting their mental health and quality of life (QoL). Physical exercise has been acknowledged as an important strategy to prevent and control numerous chronic-degenerative diseases, but unexplored in individuals with the indeterminate form of CD. The PEDI-CHAGAS study (which stands for “Home-Based Exercise Program in the Indeterminate Form of Chagas Disease” in Portuguese) aims to evaluate the effects of a home-based exercise program on physical and mental health outcomes in individuals with indeterminate form of CD.Methods and designThe PEDI-CHAGAS is a two-arm (exercise and control) phase 3 superiority randomized clinical trial including patients with indeterminate form of CD. The exclusion criteria are ConclusionThe findings from the present study may support public health intervention strategies to improve physical and mental health parameters to be implemented more effectively in this population.Clinical trial registration[https://ensaiosclinicos.gov.br/rg/RBR-10yxgcr9/], identifier [U1111-1263-0153].</p