Impact of aetiological treatment on conventional and multiplex serology in chronic Chagas disease

The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion of previously reactive serology, generally achieved many years post-treatment. The lack of reliable tests to ensure parasite clearance and to examine the effect of treatment is the main difficulty in evaluating treatment for chronic Chagas disease. Decreases of conventional and non-conventional serological titers can be useful tools to monitor the early impact of treatment. We serially measured changes in antibody levels, including seronegative conversion as well as declines in titers in 53 benznidazole-treated and 89 untreated chronically T. cruzi-infected subjects. Seronegative conversion as well as decreases of titers was significantly higher in treated compared with untreated patients. A strong concordance was found between decreases of titers of conventional and non-conventional serologic tests post-treatment, reaffirming the findings. When seronegative conversion plus decreases of titers were considered altogether, the impact of treatment was higher, in a shorter follow-up period than previously considered. New tools for monitoring the effectiveness of treatment of chronic Chagas disease are necessary, and the results showed in this study is a contribution to researchers and physicians who assist patients suffering from this disease

Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults

Background: Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-γ-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. Methodology/Principal Findings: To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4+ T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-γ and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4+ T cells with the ability to produce IFN-γ, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4+TNF-α+-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4+ T cells was evident in T. cruzi-infected children. Conclusions/Significance: Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.Fil: Albareda, María Cecilia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: de Rissio, Ana María. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Tomas, Gonzalo. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Serjan, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Alvarez, María Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Fichera, Laura Edith. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteva, Mónica Inés. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Potente, Daniel Fernando. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Armenti, Alejandro. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Tarleton, Rick L.. University of Georgia; Estados UnidosFil: Laucella, Susana Adriana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Impact of Aetiological Treatment on Conventional and Multiplex Serology in Chronic Chagas Disease

The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion of previously reactive serology, generally achieved many years post-treatment. The lack of reliable tests to ensure parasite clearance and to examine the effect of treatment is the main difficulty in evaluating treatment for chronic Chagas disease. Decreases of conventional and non-conventional serological titers can be useful tools to monitor the early impact of treatment. We serially measured changes in antibody levels, including seronegative conversion as well as declines in titers in 53 benznidazole-treated and 89 untreated chronically T. cruzi-infected subjects. Seronegative conversion as well as decreases of titers was significantly higher in treated compared with untreated patients. A strong concordance was found between decreases of titers of conventional and non-conventional serologic tests post-treatment, reaffirming the findings. When seronegative conversion plus decreases of titers were considered altogether, the impact of treatment was higher, in a shorter follow-up period than previously considered. New tools for monitoring the effectiveness of treatment of chronic Chagas disease are necessary, and the results showed in this study is a contribution to researchers and physicians who assist patients suffering from this disease

Inhibitory Receptors Are Expressed by Trypanosoma cruzi-Specific Effector T Cells and in Hearts of Subjects with Chronic Chagas Disease

We had formerly demonstrated that subjects chronically infected with Trypanosoma cruzi show impaired T cell responses closely linked with a process of T cell exhaustion. Recently, the expression of several inhibitory receptors has been associated with T cell dysfunction and exhaustion. In this study, we have examined the expression of the cytotoxic T lymphocyte antigen 4 (CTLA-4) and the leukocyte immunoglobulin like receptor 1 (LIR-1) by peripheral T. cruzi antigen-responsive IFN-gamma (IFN-γ)-producing and total T cells from chronically T. cruzi-infected subjects with different clinical forms of the disease. CTAL-4 expression was also evaluated in heart tissue sections from subjects with severe myocarditis. The majority of IFN-γ-producing CD4+ T cells responsive to a parasite lysate preparation were found to express CTLA-4 but considerably lower frequencies express LIR-1, irrespective of the clinical status of the donor. Conversely, few IFN-γ-producing T cells responsive to tetanus and diphtheria toxoids expressed CTLA-4 and LIR-1. Polyclonal stimulation with anti-CD3 antibodies induced higher frequencies of CD4+CTAL-4+ T cells in patients with severe heart disease than in asymptomatic subjects. Ligation of CTLA-4 and LIR-1 with their agonistic antibodies, in vitro, reduces IFN-γ production. Conversely, CTLA-4 blockade did not improved IFN-γ production in response to T. cruzi antigens. Subjects with chronic T. cruzi infection had increased numbers of CD4+LIR-1+ among total peripheral blood mononuclear cells, relative to uninfected individuals and these numbers decreased after treatment with benznidazole. CTLA-4 was also expressed by CD3+ T lymphocytes infiltrating heart tissues from chronically infected subjects with severe myocarditis. These findings support the conclusion that persistent infection with T. cruzi leads to the upregulation of inhibitory receptors which could alter parasite specific T cell responses in the chronic phase of Chagas disease

Treatment of Chagas disease with benznidazole and thioctic acid

Fil: Sosa-Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: Armenti, Alejandro. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Araujo, Graciela. Laboratorio Gador SA; Argentina.Fil: Viotti, Rodolfo. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Lococo, Bruno. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Ruiz Vera, Basilio. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Vigliano, Carlos. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: De Rissio, Ana María. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Segura, Elsa L. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Se realizó un ensayo clínico controlado, multicéntrico, a triple ciego, para evaluar si el tratamiento oral combinado del ácido tióctico (AT), reduce la incidencia de los efectos secundarios asociados al tratamiento con benznidazol (BZ) en pacientes infectados con Trypanosoma cruzi. Cuatro esquemas fueron asignados al azar pareados por edad, administrando placebo o AT por vía oral a razón de 50-100 mg día a dosis e intervalos variables (con y sin período pre-inducción) en combinación con BZ a dosis de 5 mg/kg/día por 30 días. Se realizaron evaluaciones en los días 10, 20, 37 y 52 de iniciado el tratamiento. Fueron enrolados 249 pacientes con edades entre 15 y 44 años. El 70.3% de los pacientes completó el tratamiento y el 17.7% restante debió suspender la medicación por causas relacionadas al BZ. La proporción de personas afectadas por al menos un efecto adverso, fue semejante entre los 4 grupos: entre 54.8 y 58%, aunque en ninguno de ellos resultó de carácter grave. Las manifestaciones clínicas adversas fueron: exantema morbiliforme (28%); prurito (13.6%); cefalea (8%); epigastralgia (6.2%); fiebre (6.2%); astenia (4.3%); náuseas (4.0%); mialgias (4.3%); vómitos (3.2%); otros (21.5%). La incidencia de experiencias adversas no difirió significativamente entre los 4 esquemas terapéuticos, ni entre los diferentes intervalos de edad de los pacientes. La asociación con ácido tióctico no demostró prevenir las manifestaciones de intolerancia a este agente. No obstante, la administración de BZ en un ciclo mensual único a pacientes infectados logró una elevada tasa de adherencia al tratamiento ambulatorio

Treatment of Chagas disease with benznidazole and thioctic acid

Fil: Sosa-Estani, Sergio. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias; Argentina.Fil: Armenti, Alejandro. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Araujo, Graciela. Laboratorio Gador SA; Argentina.Fil: Viotti, Rodolfo. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Lococo, Bruno. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Ruiz Vera, Basilio. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: Vigliano, Carlos. Ministerio de Salud de la Provincia de Buenos Aires. Hospital Eva Perón; Argentina.Fil: De Rissio, Ana María. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Segura, Elsa L. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Se realizó un ensayo clínico controlado, multicéntrico, a triple ciego, para evaluar si el tratamiento oral combinado del ácido tióctico (AT), reduce la incidencia de los efectos secundarios asociados al tratamiento con benznidazol (BZ) en pacientes infectados con Trypanosoma cruzi. Cuatro esquemas fueron asignados al azar pareados por edad, administrando placebo o AT por vía oral a razón de 50-100 mg día a dosis e intervalos variables (con y sin período pre-inducción) en combinación con BZ a dosis de 5 mg/kg/día por 30 días. Se realizaron evaluaciones en los días 10, 20, 37 y 52 de iniciado el tratamiento. Fueron enrolados 249 pacientes con edades entre 15 y 44 años. El 70.3% de los pacientes completó el tratamiento y el 17.7% restante debió suspender la medicación por causas relacionadas al BZ. La proporción de personas afectadas por al menos un efecto adverso, fue semejante entre los 4 grupos: entre 54.8 y 58%, aunque en ninguno de ellos resultó de carácter grave. Las manifestaciones clínicas adversas fueron: exantema morbiliforme (28%); prurito (13.6%); cefalea (8%); epigastralgia (6.2%); fiebre (6.2%); astenia (4.3%); náuseas (4.0%); mialgias (4.3%); vómitos (3.2%); otros (21.5%). La incidencia de experiencias adversas no difirió significativamente entre los 4 esquemas terapéuticos, ni entre los diferentes intervalos de edad de los pacientes. La asociación con ácido tióctico no demostró prevenir las manifestaciones de intolerancia a este agente. No obstante, la administración de BZ en un ciclo mensual único a pacientes infectados logró una elevada tasa de adherencia al tratamiento ambulatorio

Trypanosoma cruzi DNA in cardiac lesions of Argentinean patients with end-stage chronic Chagas heart disease

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, an

HLA Class I-T cell epitopes from trans-sialidase proteins reveal functionally distinct subsets of CD8+ T cells in chronic Chagas disease.

BACKGROUND:Previously, we identified a set of HLA-A020.1-restricted trans-sialidase peptides as targets of CD8+ T cell responses in HLA-A0201+ individuals chronically infected by T. cruzi. METHODS AND FINDINGS:Herein, we report the identification of peptides encoded by the same trans-sialidase gene family that bind alleles representative of the 6 most common class I HLA-supertypes. Based on a combination of bioinformatic predictions and HLA-supertype considerations, a total of 1001 epitopes predicted to bind to HLA A01, A02, A03, A24, B7 and B44 supertypes was selected. Ninety-six supertype-binder epitopes encoded by multiple trans-sialidase genes were tested for the ability to stimulate a recall CD8+ T cell response in the peripheral blood from subjects with chronic T. cruzi infection regardless the HLA haplotype. An overall hierarchy of antigenicity was apparent, with the A02 supertype peptides being the most frequently recognized in the Chagas disease population followed by the A03 and the A24 supertype epitopes. CD8+ T cell responses to promiscuous epitopes revealed that the CD8+ T cell compartment specific for T. cruzi displays a functional profile with T cells secreting interferon-gamma alone as the predominant pattern and very low prevalence of single IL-2-secreting or dual IFN-gamma/IL-2 secreting T cells denoting a lack of polyfunctional cytokine responses in chronic T. cruzi infection. CONCLUSIONS:This study identifies a set of T. cruzi peptides that should prove useful for monitoring immune competence and changes in infection and disease status in individuals with chronic Chagas disease

Changes in Trypanosoma cruzi-specific immune responses after treatment: surrogate markers of treatment efficacy

Fil: Laucella, Susana A. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Mazliah, Damián Pérez. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Bertocchi, Graciela. Hospital Interzonal General de Agudos "Eva Perón"; Argentina.Fil: Alvarez, María G. Hospital Interzonal General de Agudos "Eva Perón"; Argentina.Fil: Cooley, Gretchen. Center for Tropical and Emerging Global Diseases; Estados Unidos.Fil: Viotti, Rodolfo. Hospital Interzonal General de Agudos "Eva Perón"; Argentina.Fil: Albareda, María Cecilia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Lococo, Bruno. Hospital Interzonal General de Agudos "Eva Perón"; Argentina.Fil: Postan, Miriam. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Parasitología; Argentina.Fil: Armenti, Alejandro. Hospital Interzonal General de Agudos "Eva Perón"; Argentina.Fil: Tarleton, Rick L. Center for Tropical and Emerging Global Diseases; Estados Unidos.Background: As many as 20 million people are living with Trypanosoma cruzi infection in Latin American, yet few receive any treatment. The major limitation in developing and evaluating potential new drugs for their efficacy is the lack of reliable tests to assess parasite burden and elimination. Methods: Adults volunteers with chronic T. cruzi infection were evaluated clinically and stratified according to the Kuschnir classification. Individuals with group 0 and group 1 clinical status were treated with benznidazole (5 mg/kg per day for 30 days). The changes in T. cruzi-specific T cell and antibody responses, as well as in clinical status, were measured periodically over the 3-5-year follow-up period and were compared with pretreatment conditions and with values in an untreated control group. Results: The frequency of peripheral interferon (IFN)-gamma-producing T cells specific for T. cruzi declined as early as 12 months after benznidazole treatment and subsequently became undetectable in a substantial proportion of treated subjects. In addition, decreases in antibody responses to a pool of recombinant T. cruzi proteins also decreased in many of these same subjects. The shift to negative IFN-gamma T cell responses was highly associated with an early increase in IFN-gamma-producing T cells with phenotypic features of effector/effector memory cells in a subset of subjects. Benznidazole treatment also resulted in an increase in naive and early differentiated memory-like CD8(+) T cells in a majority of subjects. Conclusions: Benznidazole treatment during chronic Chagas disease has a substantial impact on parasite-specific immune response that is likely indicative of treatment efficacy and cure