Host-Derived Molecules as Novel Chagas Disease Biomarkers: Hypercoagulability Markers in Plasma

The most severe clinical symptomatology of Chagas disease affects ~30% of those chronically infected with the Trypanosoma cruzi parasite. The pathogenic mechanisms that lead to life-threatening heart and gut tissue disruptions occur "silently" for a longtime in a majority of cases. As a result, despite there are several serological and molecular methods available to diagnose the infection in its acute and chronic stages, diagnosis is often achieved only after the onset of clinical symptoms in the chronic phase of the disease. Furthermore, although there are two drugs to treat it, the assessment of their performance is impractical with current parasite-derived diagnostics, and therapeutic efficacy cannot be acknowledged in a timely manner.In this chapter we present two procedures to measure host-derived molecules as surrogates of therapeutic response against chronic T. cruzi infection. Their outputs relate to the generation and activity of thrombin, a major component of the blood coagulation cascade. This is due to the fact that a hypercoagulability state has been described to occur in chronic Chagas disease patients and revert after treatment with benznidazole

Diagnosis of Trypanosoma cruzi Infection Status using Saliva of Infected Subjects

Chagas disease has the highest prevalence of any parasitic disease in the Americas, affecting 6-7 million people. Conventional diagnosis requires a well-equipped laboratory with experienced personnel. The development of new diagnostic tools that are easy to use and adapted to the reality of affected populations and health systems is still a significant challenge. The main objective of this study was to measure Trypanosoma cruzi infection status using saliva samples of infected subjects. Blood and saliva samples from 20 T. cruzi-seropositive individuals and 10 controls were tested for T. cruzi infection using two different commercial serological tests. We have shown that detection of T. cruzi infection is possible using saliva samples, supporting the potential use of saliva to diagnose Chagas disease in humans. This method could provide a simple, low-cost but effective tool for the diagnosis of T. cruzi infection. Its noninvasive nature makes it particularly well suited for endemic areas

State-of-the-art in host-derived biomarkers of Chagas disease prognosis and early evaluation of anti-Trypanosoma cruzi treatment response

Chagas disease is caused by infection with the parasite Trypanosoma cruzi, which might lead to a chronic disease state and drive to irreversible damage to the heart and/or digestive tract tissues. Endemic in 21 countries in the Americas, it is the neglected disease with a highest burden in the region. Current estimates point at ~6 million people infected, of which ~30% will progress onto the symptomatic tissue disruptive stage. There is no vaccine but there are two anti-parasitic drugs available: benznidazole and nifurtimox. However, their efficacy is variable at the chronic symptomatic stage and both have frequent adverse effects. Since there are no prognosis markers, drugs should be administered to all T. cruzi-infected individuals in the indeterminate and early symptomatic stages. Nowadays, there are no tests-of-cure either, which greatly undermines patients' follow-up and the search of safer and more efficacious drugs. Therefore, the identification and validation of biomarkers of disease progression and/or treatment response on which to develop tests of prognosis and/or cure is a major research priority. Both parasite- and host-derived markers have been investigated. In the present manuscript we present an updated outlook of the latter

Amaryllidaceae alkaloids with anti-Trypanosoma cruzi activity

Background: Chagas disease, caused by the protozoan Trypanosoma cruzi, is a neglected disease that afects ~7 million people worldwide. Development of new drugs to treat the infection remains a priority since those currently available have frequent side efects and limited efcacy at the chronic stage. Natural products provide a pool of diver sity structures to lead the chemical synthesis of novel molecules for this purpose. Herein we analyzed the anti-T. cruzi activity of nine alkaloids derived from plants of the family Amaryllidaceae. Methods: The activity of each alkaloid was assessed by means of an anti-T. cruzi phenotypic assay. We further evalu ated the compounds that inhibited parasite growth on two distinct cytotoxicity assays to discard those that were toxic to host cells and assure parasite selectivity. Results: We identifed a single compound (hippeastrine) that was selectively active against the parasite yielding selectivity indexes of 12.7 and 35.2 against Vero and HepG2 cells, respectively. Moreover, it showed specifc activity against the amastigote stage (IC50=3.31 μM). Conclusions: Results reported here suggest that natural products are an interesting source of new compounds for the development of drugs against Chagas disease. Keywords: Chagas disease, Trypanosoma cruzi, Alkaloids, Amaryllidaceae, Hippeastrine, Phenotypic assays, Cytotoxicit

Amaryllidaceae plants: a potential natural resource for the treatment of Chagas disease

Background Chagas disease is a neglected zoonosis caused by the parasite Trypanosoma cruzi. It affects over six million people, mostly in Latin America. Drugs available to treat T. cruzi infection have associated toxicity and questionable efficacy at the chronic stage. Hence, the discovery of more effective and safer drugs is an unmet medical need. For this, natural products represent a pool of unique chemical diversity that can serve as excellent templates for the synthesis of active molecules. Methods A collection of 79 extracts of Amaryllidaceae plants were screened against T. cruzi. Active extracts against the parasite were progressed through two cell toxicity assays based on Vero and HepG2 cells to determine their selectivity profile and discard those toxic to host cells. Anti-T. cruzi-specific extracts were further qualified by an anti-amastigote stage assay. Results Two extracts, respectively from Crinum erubescens and Rhodophiala andicola, were identified as highly active and specific against T. cruzi and its mammalian replicative form. Conclusions The results retrieved in this study encourage further exploration of the chemical content of these extracts in search of new anti-T. cruzi drug development starting points

Strategies to enhance access to diagnosis and treatment for Chagas disease patients in Latin America

Introduction: Chagas disease, caused by infection with the parasite Trypanosoma cruzi, represents a huge public health problem in the Americas, where millions of people are affected. Despite the availability of two drugs against the infection (benznidazole and nifurtimox), multiple factors impede their effective usage: (1) gaps in patient and healthcare provider awareness; (2) lack of access to diagnosis; (3) drug toxicity and absence of treatment algorithms to address adverse effects; (4) failures in drug supply and distribution; and (5) inconsistent drug efficacy against the symptomatic chronic stage. Areas covered: We review new approaches and technologies to enhance access to diagnosis and treatment to reduce the disease burden. We also provide an updated picture of recently published and ongoing anti-T. cruzi drug clinical trials. Although there has been progress improving the research and development (R&D) landscape, it is unclear whether any new treatments will emerge soon. Literature search methodologies included multiple queries to public databases and the use of own-built libraries. Expert opinion: Besides R&D, there is a major need to continue awareness and advocacy efforts by patient associations, local and national governments, and international agencies. Overall, health systems strengthening is essential to ensure vector control commitments, as well as patient access to diagnosis and treatment

Characterization of digestive disorders of patients with chronic Chagas disease in Cochabamba, Bolivia

Background: Chagas disease (CD) is endemic in Latin America and particularly common in Bolivia, but there is little information on the characteristics of chronic digestive involvement. Objectives: To determine the prevalence and characterize digestive manifestations in chronic CD patients in Cochabamba, Bolivia. Methods: Eighty-five T. cruzi-seropositive individuals with or without digestive symptoms (G1 group), and fifteen T. cruzi-seronegative patients with similar digestive symptoms to those seen in CD (G2 group) were included in the study. All patients underwent a detailed history including past medical history, epidemiological information, hygiene and dietary habits, a complete physical examination, two serological tests for T. cruzi, video endoscopy, barium swallow, and barium enema. Findings: We observed digestive manifestations in T. cruzi seropositive and seronegative patients. Colonic manifestations were detected in both groups, highlighting the relevance of other confounder factors in the region. Constipation was present in 52.9% of G1 patients, 62.4% presented two or more upper digestive tract symptoms, and 5.9% of them presented esophageal manifestations. Helicobacter pylori infection was detected in 58.8% of G1 patients, and all patients presented gastritis on endoscopy. Conclusions: Prevalence of digestive involvement in CD patients is higher than expected. However, digestive symptoms are not always caused by T. cruzi infection and require differential diagnoses

Response to `letter to the editor: 'Strategies to enhance access to diagnosis and treatment for Chagas disease patients in Latin America'´

Dear Editor, We appreciate the comments on our recent review article about strategies to enhance access to diagnosis and treatment for Chagas disease patients [1,2]. We also appreciate the opportunity to respond to them, and expand the discussion on this crucial topic given that it is estimated that no more than 1% of the infected population by Trypanosoma cruzi (of ~7 million people) ultimately get access to treatment [3]. The letter comments mainly refer to two of the sections of the review article: diagnostics to detect the infection (section 2), and treatment opportunities and possibilities (section 7)

Plasma-Derived Extracellular Vesicles as Potential Biomarkers in Heart Transplant Patient with Chronic Chagas Disease

Chagas disease is emerging in countries to which it is not endemic. Biomarkers for earlier therapeutic response assessment in patients with chronic Chagas disease are needed. We profiled plasma-derived extracellular vesicles from a heart transplant patient with chronic Chagas disease and showed the potential of this approach for discovering such biomarkers

Implantation of CPT1AM-expressing adipocytes reduces obesity and glucose intolerance in mice

Obesity and its associated metabolic comorbidities are a rising global health and social issue, with novel therapeutic approaches urgently needed. Adipose tissue plays a key role in the regulation of energy balance and adipose tissue-derived mesenchymal stem cells (AT-MSCs) have gained great interest in cell therapy. Carnitine palmitoyltransferase 1A (CPT1A) is the gatekeeper enzyme for mitochondrial fatty acid oxidation. Here, we aimed to generate adipocytes expressing a constitutively active CPT1A form (CPT1AM) that can improve the obese phenotype in mice after their implantation. AT-MSCs were differentiated into mature adipocytes, subjected to lentivirus-mediated expression of CPT1AM or the GFP control, and subcutaneously implanted into mice fed a high-fat diet (HFD). CPT1AM-implanted mice showed lower body weight, hepatic steatosis and serum insulin and cholesterol levels alongside improved glucose tolerance. HFD-induced increases in adipose tissue hypertrophy, fibrosis, inflammation, endoplasmic reticulum stress and apoptosis were reduced in CPT1AM-implanted mice. In addition, the expression of mitochondrial respiratory chain complexes was enhanced in the adipose tissue of CPT1AM-implanted mice. Our results demonstrate that implantation of CPT1AM-expressing AT-MSC-derived adipocytes into HFD-fed mice improves the obese metabolic phenotype, supporting the future clinical use of this ex vivo gene therapy approach