Peptídeo intestinal vasoativo (VIP) e seus receptores na fase crônica da doença de Chagas humana

Abstract

The interconnection between immune and neuroendocrine systems influences regulation of inflammatory responses. The possible relevance that this integrative response may have during the course of Chagas disease remains poorly characterized. In this context, our study was designed to determine the expression of vasoactive intestinal peptide (VIP) in blood from the indeterminate and cardiac polarized forms of Chagas disease, moreover, we determined whether the differential expression of VIP is associated with the development of cardiomyopathy in individuals infected with Trypanosoma cruzi. Finally, we analyzed gene polymorphisms of VIP receptors, VPAC1 and VPAC2, and performed correlation analysis of these polymorphisms with the different clinical forms of Chagas disease. VIP plasma levels were measured by ELISA and clinical parameters such as left ventricular ejection fraction and left ventricular diastolic diameter were taken by echocardiographic exams. Polymorphism analyses were performed using Real-time PCR. Our results demonstrated that low plasma levels of VIP were associated with the cardiac morbidity in Chagas disease. Accordingly, correlation analysis showed that low plasma levels of VIP were associated with worse cardiac function, as determined by left ventricular ejection fraction and left ventricular diastolic diameter values. Polymorphism analysis showed a significant association between VPAC1 and the indeterminate form of Chagas disease development. Our results indicate that VIP expression and its receptors polymorphism may be important in determining susceptibility to progression from mild to severe forms of Chagas disease.