Comparing in vivo bioluminescence imaging and the Multi-Cruzi immunoassay platform to develop improved Chagas disease diagnostic procedures and biomarkers for monitoring parasitological cure

Galectin-3 (Gal-3) and the tissue inhibitor of matrix metalloproteinase (TIMP-2) as potential biomarkers for the clinical evolution of chronic Chagas cardiomyopathy

BACKGROUND

Chronic Chagas cardiomyopathy (CCC) is responsible for the highest morbidity and worst prognosis in Chagas disease patients. However, predicting factors that correlate with disease progression, morbidity, and mortality is challenging. It is necessary to have simple, quantitative, and economical risk biomarkers that add value to conventional methods and assist in the diagnosis and prognosis of patients with CCC or in evolution.

OBJECTIVES

We evaluated molecules related to cardiac remodeling and fibrosis, such as MMP-2, MMP-9, TIMP-2, TIMP-1, PICP, CTXI, and Gal-3, and correlated these biomarkers with echocardiographic variables (LVDD, LVEF, and E/e' ratio).

METHODS

Blood samples from Chagasic patients without apparent cardiopathy (WAC), CCC patients, and healthy individuals were used to perform plasma molecule dosages using Luminex or ELISA.

RESULTS

MMP-2 and TIMP-2 presented higher levels in CCC; in these patients, the inhibitory role of TIMP-2 over MMP-2 was reinforced. The ratio of MMP-2/TIMP-2 in WAC patients showed a bias in favor of the gelatinase pathway. MMP-9 and TIMP-1 showed higher levels in Chagas patients compared to healthy subjects. PICP and CTXI are not associated with cardiac deterioration in Chagas disease. Increased levels of Gal-3 are associated with worse cardiac function in CCC. Receiver operating characteristic (ROC) curve analysis identified Gal-3 and TIMP-2 as putative biomarkers to discriminate WAC from cardiac patients.

CONCLUSIONS

Among the molecules evaluated, Gal-3 and TIMP-2 have the potential to be used as biomarkers of cardiac remodeling and progressive myocardial fibrosis in Chagas disease.

Fifteen Years after the Definition of Trypanosoma cruzi DTUs: What Have We Learned?

Trypanosoma cruzi, the protozoan causative of Chagas disease (ChD), exhibits striking genetic and phenotypic intraspecific diversity, along with ecoepidemiological complexity. Human-pathogen interactions lead to distinct clinical presentations of ChD. In 2009, an international consensus classified T. cruzi strains into six discrete typing units (DTUs), TcI to TcVI, later including TcBat, and proposed reproducible genotyping schemes for DTU identification. This article aims to review the impact of classifying T. cruzi strains into DTUs on our understanding of biological, ecoepidemiological, and pathogenic aspects of T. cruzi. We will explore the likely origin of DTUs and the intrinsic characteristics of each group of strains concerning genome organization, genomics, and susceptibility to drugs used in ChD treatment. We will also provide an overview of the association of DTUs with mammalian reservoirs, and summarize the geographic distribution, and the clinical implications, of prevalent specific DTUs in ChD patients. Throughout this review, we will emphasize the crucial roles of both parasite and human genetics in defining ChD pathogenesis and chemotherapy outcome.

State-of-the-Art in the Drug Discovery Pathway for Chagas Disease: A Framework for Drug Development and Target Validation

Chagas disease is the most important protozoan infection in the Americas, and constitutes a significant public health concern throughout the world. Development of new medications against its etiologic agent, Trypanosoma cruzi, has been traditionally slow and difficult, lagging in comparison with diseases caused by other kinetoplastid parasites. Among the factors that explain this are the incompletely understood mechanisms of pathogenesis of T. cruzi infection and its complex set of interactions with the host in the chronic stage of the disease. These demand the performance of a variety of in vitro and in vivo assays as part of any drug development effort. In this review, we discuss recent breakthroughs in the understanding of the parasite's life cycle and their implications in the search for new chemotherapeutics. For this, we present a framework to guide drug discovery efforts against Chagas disease, considering state-of-the-art preclinical models and recently developed tools for the identification and validation of molecular targets.