Óscar A. Reboreda-Hernández, Pathology Laboratory, Department of Morphology, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
Rocío Ortiz-Butron, Neurobiology Laboratory, Department of Physiology, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
Benjamín Nogeda-Torres, Helmintology Laboratory, Department of Parasitology, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
Nayeli González-Rodríguez, Pathology Laboratory, Department of Morphology, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico

Objective: To evaluate the influence of thyroid hormones (THs) on Chagas disease (CD) to improve understanding of host susceptibility factors. Methods: In vitro assays included growth curves in liver infusion tryptose medium to assess the effect of TH on Trypanosoma cruzi metabolism, phagocytosis assays in macrophages sensitized with TH, and enzyme-linked immunosorbent assay (ELISA) tests to determine anti-T. cruzi antibody levels. In vivo experiments were conducted on three groups of BALB/c mice: hypothyroid (induced by methimazole), hyperthyroid (induced by levothyroxine sodium), and euthyroid (control). T. cruzi cardiotropic NINOA strain (TDU-I group) was used. Parasitemia, mortality, and histopathology were evaluated. Results: No significant changes were observed in parasite growth kinetics in vitro. However, macrophages treated with TH exhibited increased phagocytic capacity. ELISA results showed higher levels of anti-T. cruzi antibodies in TH-treated hosts. In vivo, parasitemia varied among groups, with the highest mortality and tissue damage observed in hypothyroid mice. Conclusions: TH modulates the immune response, disease progression, and outcomes in CD. These insights suggest that thyroid status evaluation could be a key component for personalized clinical management.

Keywords: Trypanosoma cruzi. Thyroid hormones. Phagocytosis. Chagas disease. Immune system.