Apolipoprotein A1 and Fibronectin Fragments as Markers of Cure for the Chagas Disease.

Chagas disease (CD), endemic from Latin America, affects more than 8 million people, and the disease keeps spreading around the world due to population migrations. The treatment options for CD are currently limited to two drugs, benznidazole (BZ) and nifurtimox (Nfx), which are often unsatisfactory in chronically infected patients. To date, the only accepted marker of the cure is seroconversion (the disappearance of Trypanosoma cruzi antibodies in the patient's serum), which can take decades to occur, if ever. The lack of posttreatment test-of-cure often prevents appropriate patient counseling and limits the development of new drugs. Without a doubt, reliable biomarkers for parasitological cure are urgently needed. Several pieces of evidence suggest that apolipoprotein A1 and fibronectin fragments are produced during the infection as part of the process of T. cruzi cell invasion and can thus be used as its surrogate biomarkers. In this chapter, we present a standardized method to evaluate these fragments in serum using mass spectrometry and immunoblotting in CD patients for diagnosis, prognosis, and treatment assessment purposes.