Avaliação dos níveis de melatonina e mediadores inflamatórios na infecção por Leishmania em pacientes hiperglicêmicos

Abstract

American Cutaneous Leishmaniasis (ACL) is a neglected zoonotic disease that affects the skin and mucous membranes, resulting in single or multiple ulcerative lesions. Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder, consisting of chronic hyperglycemia, resulting from failure in insulin secretion and/or action, representing a serious and growing health problem and one of the main causes of mortality in the world. Commonly, infectious diseases are more recurrent in diabetic patients, due to immune dysfunction. Marked and chronic inflammation is a common feature in these two comorbidities. The hormone melatonin is an endogenously synthesized indolamine, exerting important immunomodulatory and neuroprotective actions, in addition to the temporal maintenance of the biological rhythm. Knowledge about the effect of Leishmania infection on the biological clock of the host is still scarce, therefore, the objective of this work was to evaluate the relationship of melatonin with inflammatory mediators in Leishmania infection in hyperglycemic patients. Serum levels of the hormone melatonin, glucose and inflammatory mediators (CRP, IL-4, TNF-α) were evaluated in healthy individuals, with leishmaniasis, with diabetes and with an association of both diseases. An increase in TNF-α was observed in the test groups in relation to the control. In addition, reduced levels of melatonin in the ACL group (43.12±4.44 pg.mL-1 ), with a significant difference in relation to the control group (60.79±12.09 pg.mL-1 ), were observed higher melatonin concentrations of the ACL +DMT2 group (69.65±7.03 pg.mL-1 ) in relation to the isolated groups. Our study provides evidence to consider that TNF-α may affect melatonin production in patients with cutaneous leishmaniasis. On the other hand, diabetic patients affected by ACL had melatonin production matching healthy individuals, through additional mechanisms, which need to be understood, seeking to clarify whether the daily rhythm of melatonin can be restored in associated diseases.