Assay Monitors Cardiomyopathy in Chagas Disease

A serum assay for a protein in the blood has been used to monitor damage to the heart in patients with chronic Chagas disease.

A highly sensitive assay for measuring the protein biomarker, cardiac troponin T (cTnT), has been used to assess heart injury in patients suffering from the tropical disease caused by the blood-borne protozoan parasite, Trypanosoma cruzi.

In an international study carried out at the Charité University Hospital, (Berlin, Germany), serum cTnT was measured in 26 healthy subjects and in 179 patients with chronic Chagas disease, of whom 86 were asymptomatic, 71 were suffering from cardiomyopathy with or without megacolon, and 22 were suffering from megacolon exclusively. Megacolon is an abnormal dilation of the colon is often accompanied by a paralysis of the peristaltic movements of the bowel.

For serum cTnT measurement, the conventional, fourth-generation assay and the highly sensitive assay provided by Roche Diagnostics GmbH (Mannheim, Germany), were performed using Roche's Elecsys-2010 chemistry analyzer. Serum cTnT was significantly higher in patients with cardiomyopathy with or without megacolon than in healthy subjects, asymptomatic subjects, and patients with megacolon, and the cTnT value was correlated with the severity of the cardiomyopathy. The lower limit of detection for the highly sensitive assay, was 3 ng/L, and was best at distinguishing patients with, and without, heart injury. C-reactive protein and interleukin 6 were found to parallel cTnT changes in both the different Chagas groups and the cardiomyopathy groups separated by disease severity.

The authors commented that the introduction of cardiac troponin immunoassays with improved sensitivity enables the mirroring of minor, but distinct, cardiac troponin elevations with diagnostic and prognostic effect in pathophysiological conditions of the heart, such as inflammation and cardiomyopathy. With the highly sensitive cTnT assay, a diagnostic tool is now available that supplies data usable in chronic Chagas disease for diagnosis, prognosis, and monitoring of cardiomyopathy. The cTnT measurement could, in their view, supplement electrocardiography, echocardiography, and radiological imaging in patients with chronic Chagas disease, and in special circumstances, be applied before these other diagnostic tools. The study was published in February 2011, in the Archives of Pathology and Laboratory Medicine.

Related Links:
Charité University Hospital
Roche Diagnostics