Call for Consensus in the Evaluation of Circulating Matrix Metalloproteinases in Chagas Disease.

Infection with the Trypanosoma cruzi parasite is endemic in parts of America. Approximately 30% of people infected develop Chagas cardiomyopathy, the most common cause of heart failure in these regions. No suitable biomarker that reflects the evolution of the disease has been widely accepted as of yet. There is substantial evidence, however, of a strong inflammatory reaction following infection with T. cruzi that could activate matrix metalloproteinases (MMPs). Emerging research suggests the involvement of MMPs in Chagas cardiomyopathy and there is a growing interest in measuring the blood levels of MMPs as diagnostic and/or prognostic indicators of heart damage in Chagas patients. This perspective discusses the lack of consensus on the best method for MMP evaluation. Some studies are based on MMP concentrations and activities in serum whereas others use plasma. We believe that these different methods of evaluation have led to incongruent and poorly comparable data on the blood levels of MMPs in Chagas patients. A standard for the preparation of blood samples needs to be adopted for the study of MMPs as markers of Chagas cardiomyopathy to ensure better comparability of research results.