Abstract. The extent of inflammation, fibrosis, and progression of chronic Chagas heart disease (cChHD) was associated with persistence of parasite DNA in cardiac lesions of necropsies or explants from Argentinean cChHD patients. A Trypanosoma cruzi−based polymerase chain reaction showed a positive result in 1) 15% of cardiac sections with less than 10 mononuclear inflammatory cells/high-power field (440×) (MNC/HPF), 89% with 10-19 MNC/HPF, and 100% with more than 20 MNC/HPF (P < 0.0001); 2) 33% with less than 10% fibrosis, 79% with 10-19% fibrosis, and 100% with more than 20% fibrosis (P < 0.01); 3) 25% of specimens from patients classified in Kuschnir groups 0 and I, 70% in group II and 90% in group III (P < .001); and 4) 45% and 90% of the specimens from cChHD patients without or with heart failure, respectively (P < 0.01). These findings stress the role of the parasite in pathogenesis and disease progression of cChHD.

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Abstract. The aim of this work was to investigate the potential usefulness of Trypanosoma cruzi lysate, recombinant protein JL7, and peptides P013, R13, JL18, JL19, and P0β as serological markers for human Chagas disease. We analyzed 228 sera from Brazilian Chagas disease patients classified into four clinical groups and 108 from non-chagasic patients. We defined the diagnostic sensitivity, specificity, and Kappa index measured by enzyme-linked immunosorbent assay (ELISA). As previously described, the highest values of diagnostic parameters were achieved for T. cruzi lysate and JL7; peptide P013 showed high specificity but low sensitivity. The other peptides resulted in lower sensitivity and specificity in our ELISA than T. cruzi lysate and JL7 protein. Antibodies against JL7 protein were mainly detected in sera from patients with severe chagasic cardiomyopathy, compared with those from the indeterminate form, whereas peptides failed to discriminate between the clinical forms of the disease.Chagas disease, caused by the hemoflagellate Trypanosoma cruzi, is a widespread tropical disease affecting at least 8 million people primarily in Latin American countries.1 The acute phase lasts 1 or 2 months and is usually symptomless, 2 however most of the infected individuals enter a life-long chronic phase with its asymptomatic and symptomatic forms. The asymptomatic, also called indeterminate form is characterized by the absence of clinical symptoms. However,~40% of persons with chronic T. cruzi infection develop symptoms of visceral damage, which may include cardiac lesions, digestive alterations, or both clinical manifestations (cardiac plus digestive). 2In the chronic phase, the primary method for diagnosis is the search of antibodies by serological testing, whereas the secondary diagnostic techniques are parasitological tests.1 So far, conventional serological tests include complement fixation, 3,4 indirect immunofluorescence assay (IFA), 5 indirect hemagglutination assay (IHA), 6 direct agglutination with 2-mercaptoethanol (DA-2ME), 7 and enzyme-linked immunosorbent assay (ELISA). [8][9][10] These tests usually use crude or semi-purified parasite preparations, often derived from a stage present only in the insect and in cultures at 26 C (epimastigote) but absent in the human host. Other assays incorporate more defined parasite components, like multiple fusion proteins containing epitopes from various T. cruzi antigens.11-15 Moreover, a rapid immunochromatographic assay (Chagas Stat-Pak, Chembio Diagnostic Systems, Medford, NY) has also been developed by employing a mixture of T. cruzi recombinant antigens, presenting a different degree of performance. [16][17][18] However, in the absence of a true gold standard, it is still necessary to carry out at least two different serological tests to establish a reliable diagnosis of Chagas disease. Indeed, the World Health Organization (WHO) consensus guidelines recommend to perform a third assay or repeat sampling to confirm or exclude the diagnosis if two serological tests ...

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