Biomarkers of therapeutic responses in chronic Chagas disease: state of the art and future perspectives

The definition of a biomarker provided by the World Health Organization is anysubstance, structure, or process that can be measured in the body, or its productsand influence, or predict the incidence or outcome of disease. Currently, the lack ofprognosis and progression markers for chronic Chagas disease has posed limitationsfor testing new drugs to treat this neglected disease. Several molecules andtechniques to detect biomarkers in Trypanosoma cruzi-infectedpatients have been proposed to assess whether specific treatment with benznidazole ornifurtimox is effective. Isolated proteins or protein groups from differentT. cruzi stages and parasite-derived glycoproteins and syntheticneoglycoconjugates have been demonstrated to be useful for this purpose, as havenucleic acid amplification techniques. The amplification of T. cruziDNA using the real-time polymerase chain reaction method is the leading testfor assessing responses to treatment in a short period of time. Biochemicalbiomarkers have been tested early after specific treatment. Cytokines and surfacemarkers represent promising molecules for the characterisation of host cellularresponses, but need to be further assessed.