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The innate immune response from diamniotic and dichorionic twin brothers congenitally infected with Trypanosoma. cruzi (strain DTU-V) who displayed different clinical symptomatology was studied. While Brother I manifested severe cardiac and digestive disorders, the Brother II showed slight splenomegaly. The secretion level of IL-1β, TNF-α, IL-12, IL-10, IFN-α and IL-6 cytokines produced after stimulation of peripheral blood cells with TLR-2, TLR-4 and TLR-9 ligands was determined pre- and post-benznidazole treatment. Cells from 10 uninfected infants born to mothers seropositive for Chagas disease were included as control. The obtained data show that the cells of Brother I secreted lower levels of the pro-inflammatory cytokines IL-1β and TNF-α (upon TLR-2 and TLR-4 stimulation) relative to those secreted by cells from Brother II and uninfected controls. The cells from Brother II secreted high levels of the IL-1β cytokine following TLR-2 stimulation relative to uninfected controls. The cells from both brothers secreted a higher level of IL-6, following TLR-4 stimulation, than that secreted by uninfected infant cells. After treatments, the cytokine secretion levels were similar in both children and comparable to those of uninfected donors. Treatment success in Brother I and treatment interruption in Brother II was detected by the use of serological biomarkers (KMP11, HSP70, PFR2, Tgp63) as well as follow-up done by PCR. Therefore, the Brother II required a second treatment. The data presented suggest that benznidazol treatment allows the innate immune system to reach a fully functional status similar to that of uninfected subjects., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Nowadays, the techniques available for chronic Chagas' disease diagnosis are very sensitive; however, they do not allow discrimination of the patient's clinical stages of the disease. The present paper describes that three out of the five different repeats contained in the Trypanosoma cruzi TcCA-2 membrane protein (3972-FGQAAAGDKPPP, 6303-FGQAAAGDKPAP, and 3973-FGQAAAGDKPSL) are recognized with high sensitivity (>90%) by sera from chronic Chagas' disease patients and that they are not recognized by sera from patients in the acute phase of the disease. A total of 133 serum samples from chagasic patients and 50 serum samples from healthy donors were tested. In addition, sera from 15 patients with different autoimmune diseases, 43 serum samples from patients suffering an infectious disease other than Chagas' disease, and 38 serum samples from patients with nonchagasic cardiac disorders were also included in this study. The residue 3973 peptide shows a specificity of >98%, as it is not recognized by individuals with autoimmune and inflammatory processes or by patients with a nonchagasic cardiomyopathy. Remarkably, the levels of antibody against the 3973 epitope detected by the sera from Chagas' disease patients in the symptomatic chronic phase, involving cardiac or digestive alterations, are higher than those detected by the sera from Chagas' disease patients in the indeterminate phase of the disease. It is suggested that the diagnostic technique described could also be used to indicate the degree of pathology. The amino acids F, Q, and DKP located in the peptide at positions 1, 3, and 8 to 10, respectively, are essential to conform to the immunodominant antigenic epitope.

Background: Conventional serological tests, using total soluble proteins or a cocktail of recombinant proteins from T. cruzi as antigens, are highly sensitive for Chagas disease diagnosis. This type of tests, however, does not seem to be reliable tools for short- and medium-term monitoring of the evolution of patients after antiparasitic treatment. The aim of the present study was to search for immunological markers that could be altered in the sera from Chagas disease patients after benznidazole treatment, and therefore have a potential predictive diagnostic value., Methods: We analyzed the reactivity of sera from chagasic patients during different clinical phases of the disease against a series of immunodominant antigens, known as KMP11, PFR2, HSP70 and Tgp63. The reactivity of the sera from 46 adult Chronic Chagas disease patients living in a non-endemic country without vector transmission of T. cruzi (15 patients in the indeterminate stage, 16 in the cardiomiopathy stage and 16 in the digestive stage) and 22 control sera from non-infected subjects was analyzed. We also analyzed the response dynamics of sera from those patients who had been treated with benznidazole., Results: Regardless of the stage of the sickness, the sera from chagasic patients reacted against KMP11, HSP70, PFR2 and Tgp63 recombinant proteins with statistical significance relative to the reactivity against the same antigens by the sera from healthy donors, patients with autoimmune diseases or patients suffering from tuberculosis, leprosy or malaria. Shortly after benznidazole treatment, a statistically significant decrease in reactivity against KMP11, HSP70 and PFR2 was observed (six or nine month). It was also observed that, following benznidazole treatment, the differential reactivity against these antigens co-relates with the clinical status of the patients., Conclusions: The recombinant antigens KMP11, PFR2, Tgp63 and HSP70 are recognized by Chagas disease patients' sera at any clinical stage of the disease. Shortly after benznidazole treatment, a drop in reactivity against three of these antigens is produced in an antigen-specific manner. Most likely, analysis of the reactivity against these recombinant antigens may be useful for monitoring the effectiveness of benznidazole treatment.