Assessment of a combined treatment with a therapeutic vaccine and benznidazole for the Trypanosoma cruzi chronic infection.

The difficulties encountered in achieving treatments for chronic Chagas disease have promoted the investigation of new therapeutic strategies. In this study, we used two murine models of Trypanosoma cruzi chronic infection to determine the usefulness of applying a therapeutic vaccine alone or followed by benznidazole (Bz) chemotherapy. A vaccine formulation based on an N-terminal fragment of Trans-sialidase (TS) and Immunostimulant Particle Adjuvant (ISPA) - TSNt-ISPA was obtained. Firstly, the immunogenicity and protective capacity of TSNt-ISPA was demonstrated as a prophylactic formulation in an acute model of infection. Later, the formulation was assessed as a therapeutic vaccine alone or combined with (Bz) using two models of chronic infection. BALB/c mice chronically infected with Sylvio X10/4 or Tulahuen cl2 T. cruzi strains were not treated as control or treated only with the therapeutic vaccine TSNt-ISPA, with a combined treatment TSNt-ISPA+Bz (Bz applied after the vaccine), or only with Bz. The vaccination schedule consisted of TSNt-ISPA administration at days110, 120, and 130 post-infection (pi) and Bz administration was performed daily from day 140 to 170 pi. At day 273 pi, electrocardiographic (ECG) parameters, heart parasite load, myocarditis, and heart fibrosis were assessed. In both models, therapeutic administration of TSNt-ISPA reduced ECG alterations and the cardiac tissue damage observed in the chronic phase. Moreover, vaccine treatment significantly decreased heart parasite load in both Sylvio X10/4 and Tulahuen cl2 infected mice. The combined treatment, but not Bz or vaccine administration alone, allowed to restore ECG parameters in Tulahuen cl2 infected mice. The results indicate the usefulness of the therapeutic TSNt-ISPA formulation in BALB/c mice chronically infected with Sylvio X10/4 or Tulahuen cl2 strain. For the mice infected with T. cruzi Tulahuen cl2 strain, the combined treatment with the vaccine and Bz had a more positive effect on the course of heart disease than the individual treatments with the vaccine or Bz alone.

Seroprevalence of anti-SARS-CoV-2 IgG in asymptomatic and pauci-symptomatic people over a 5 month survey in Argentina.

OBJECTIVE: To evaluate the seroprevalence of COVID-19 infection in pauci-symptomatic and asymptomatic people, the associated epidemiological factors, and IgG antibody kinetic over a 5-month period to get a better knowledge of the disease transmissibility and the rate of susceptible persons that might be infected. METHODS: Seroprevalence was evaluated by a cross-sectional study based on the general population of Santa Fe, Argentina (non-probabilistic sample) carried out between July and November 2020. A subgroup of 20 seropositive individuals was followed-up to analyze IgG persistence. For the IgG anti-SARS-CoV-2 antibodies detection, the COVID-AR IgG® ELISA kit was used. RESULTS: 3 000 individuals were included conforming asymptomatic and pauci-symptomatic groups (n=1 500 each). From the total sample, only 8.83% (n=265) presented reactivity for IgG anti-SARS-CoV-2. A significant association was observed between positive anti-SARS-CoV-2 IgG and a history of contact with a confirmed case; the transmission rate within households was approximately 30%. In the pauci-symptomatic group, among the seropositive ones, anosmia and fever presented an OR of 16.8 (95% CI 9.5-29.8) and 2.7 (95% CI 1.6-4.6), respectively (p <0.001). In asymptomatic patients, IgG levels were lower compared to pauci-symptomatic patients, tending to decline after 4 months since the symptoms onset. CONCLUSION: We observed a low seroprevalence, suggestive of a large population susceptible to the infection. Anosmia and fever were independent significant predictors for seropositivity. Asymptomatic patients showed lower levels of antibodies during the 5-month follow-up. IgG antibodies tended to decrease over the end of this period regardless of symptoms.

Seroprevalence of anti-SARS-CoV-2 IgG in asymptomatic and pauci-symptomatic people over a 5 month survey in Argentina

[ABSTRACT]. Objective. To evaluate the seroprevalence of COVID-19 infection in pauci-symptomatic and asymptomatic people, the associated epidemiological factors, and IgG antibody kinetic over a 5-month period to get a better knowledge of the disease transmissibility and the rate of susceptible persons that might be infected. Methods. Seroprevalence was evaluated by a cross-sectional study based on the general population of Santa Fe, Argentina (non-probabilistic sample) carried out between July and November 2020. A subgroup of 20 seropositive individuals was followed-up to analyze IgG persistence. For the IgG anti-SARS-CoV-2 antibodies detection, the COVID-AR IgG® ELISA kit was used. Results. 3 000 individuals were included conforming asymptomatic and pauci-symptomatic groups (n=1 500 each). From the total sample, only 8.83% (n=265) presented reactivity for IgG anti-SARS-CoV-2. A significant association was observed between positive anti-SARS-CoV-2 IgG and a history of contact with a confirmed case; the transmission rate within households was approximately 30%. In the pauci-symptomatic group, among the seropositive ones, anosmia and fever presented an OR of 16.8 (95% CI 9.5-29.8) and 2.7 (95% CI 1.6-4.6), respectively (p <0.001). In asymptomatic patients, IgG levels were lower compared to pauci-symptomatic patients, tending to decline after 4 months since the symptoms onset. Conclusion. We observed a low seroprevalence, suggestive of a large population susceptible to the infection. Anosmia and fever were independent significant predictors for seropositivity. Asymptomatic patients showed lower levels of antibodies during the 5-month follow-up. IgG antibodies tended to decrease over the end of this period regardless of symptoms.

[RESUMEN]. Objetivo. Evaluar la seroprevalencia de la infección por el virus causante de la COVID-19 en personas paucisintomáticas y asintomáticas, los factores epidemiológicos asociados y la cinética de los anticuerpos IgG durante un período de cinco meses para conocer mejor la transmisibilidad de la enfermedad y la tasa de personas susceptibles a estar infectadas. Métodos. Se evaluó la seroprevalencia mediante un estudio transversal basado en la población general de Santa Fe, Argentina (muestra no probabilística) llevado a cabo entre julio y noviembre del 2020. Se realizó un seguimiento de un subgrupo de 20 personas seropositivas para analizar la persistencia de los anticuerpos IgG. Para la detección de los anticuerpos IgG contra SARS-COV-2, se empleó el kit ELISA COVID-AR IgG®. Resultados. Hubo 3 000 participantes divididos en un grupo asintomático y un grupo paucisintomático (n=1 500 cada grupo). De la muestra total, solo 8,83% (n=265) presentó una reactividad de IgG contra el SARS-CoV-2. Se observó una asociación significativa entre anticuerpos IgG positivos contra el SARS-CoV-2 y antecedente de contacto con un caso confirmado. La tasa de transmisión en el hogar fue de 30% aproximadamente. En el grupo paucisintomático, entre las personas seropositivas, la anosmia y la fiebre presentaron un OR de 16,8 (IC 95% 9,5-29,8) y 2,7 (IC 95% 1,6-4,6), respectivamente (p <0,001). En los pacientes asintomáticos, los niveles de IgG fueron inferiores en comparación con los pacientes paucisintomáticos, con tendencia a la baja pasados cuatro meses desde la aparición de los síntomas. Conclusiones. Se observó una seroprevalencia baja, indicadora de una gran población susceptible a la infección. La anosmia y la fiebre fueron factores predictivos independientes de relevancia para la seropositividad. Los pacientes asintomáticos mostraron niveles inferiores de anticuerpos durante el seguimiento de cinco meses. Los anticuerpos IgG tendieron a disminuir hacia el final del período con independencia de los síntomas.

[RESUMO]. Objetivo. Avaliar a soroprevalência de anticorpos contra a COVID-19 em indivíduos paucissintomáticos e assintomáticos, os fatores epidemiológicos associados e a cinética dos anticorpos da classe IgG em um período de 5 meses, visando aprimorar o conhecimento sobre a transmissibilidade da doença e a taxa de suscetíveis à infecção. Métodos. Inquérito transversal de soroprevalência realizado na população geral (amostra não probabilística) de Santa Fé, na Argentina, entre julho e novembro de 2020. Um subgrupo de 20 indivíduos soropositivos foi acompanhado para analisar a persistência de anticorpos IgG. O kit de ensaio imunoenzimático (ELISA) COVID-AR IgG® foi usado para a detecção de anticorpos IgG contra SARS-CoV-2. Resultados. A amostra compreendeu 3 000 indivíduos, divididos entre assintomáticos e paucissintomáticos (n = 1.500 por grupo). Deste total, somente 8,83% (n = 265) apresentaram reatividade, com a detecção de anticorpos IgG contra SARS-CoV-2. Observou-se uma associação significativa entre a presença de anticorpos IgG contra SARS-CoV-2 e histórico de contato com caso confirmado. A taxa de transmissão intradomiciliar foi de aproximadamente 30%. No grupo paucissintomático, entre os soropositivos, o odds ratio (OR) para anosmia foi de 16,8 (IC 95% 9,5–29,8), e para febre, 2,7 (IC 95% 1,6–4,6) (p <0,001). Os indivíduos assintomáticos apresentaram níveis de IgG mais baixos que os paucissintomáticos, com uma tendência de declínio após 4 meses do início dos sintomas. Conclusões. Observou-se uma soroprevalência baixa de anticorpos contra a COVID-19 na população estudada, o que indica um grande número de pessoas suscetíveis à infecção. Anosmia e febre foram preditores importantes independentes de soropositividade. Os assintomáticos apresentaram níveis mais baixos de anticorpos aos 5 meses de acompanhamento. Houve uma tendência de redução dos anticorpos IgG ao final deste período, independentemente da presença de sintomas.

Functional Autoreactive Anti-ß2 Adrenergic Antibodies May Contribute to Insulin Resistance Profile in Patients with Chronic Chagas Disease.

Potential activation of ß2 adrenergic receptors (ß2AR) by specific autoreactive antibodies (Abs) that arise during the host reaction to Trypanosoma cruzi, could contribute to the elevated prevalence of metabolic disturbances described in patients with chronic Chagas disease (CCD). This study aimed to determine the prevalence of anti-ß2AR Abs in patients with CCD, as well as the correlation of these Abs with the presence of glucose and lipid metabolism disturbances, in order to explore their association with an insulin resistance profile. Additionally, we tested the functional effects of anti-ß2AR Abs employing an in vitro bioassay with neuroendocrine cells expressing ß2AR. A clinical and metabolic evaluation including an OGTT was performed in 80 CCD patients and 40 controls. Anti-ß2AR Abs were measured by an in-house-developed ELISA, and the ß2 adrenergic activity of affinity-purified IgG fractions from patient' sera were assayed in CRE-Luc and POMCLuc transfected AtT-20 cells. A higher proportion of dysglycemia (72.5% vs. 37.5%; p = 0.001) was observed in the CCD group, accompanied by increased HOMA2-IR (p = 0.019), especially in subjects with Abs (+). Anti-ß2AR Abs reactivity (7.01 (2.39-20.5); p = 0.0004) and age >50 years (3.83 (1.30-11.25); p = 0.014) resulted as relevant for IR prediction (AUC: 0.786). Concordantly, Abs (+) CCD patients showed elevated metabolic risk scores and an increased prevalence of atherogenic dyslipidemia (p = 0.040), as compared to Abs (-) patients and controls. On functional bioassays, Abs exerted specific and dose-dependent ß2-agonist effects. Our findings suggest that anti-ß2AR Abs may induce the activation of ß2AR in other tissues besides the heart; furthermore, we show that in patients with CCD these Abs are associated with an insulin resistance profile and atherogenic dyslipidemia, providing biological plausibility to the hypothesis that adrenergic activation by anti-ß2AR Abs could contribute to the pathogenesis of metabolic disturbances described in CCD patients, increasing their cardiovascular risk.

Increased epicardial adipose tissue thickness associated with increased metabolic risk and the presence of heart failure in patients with Chronic Chagas disease.

BACKGROUND: It has been described that Trypanosoma cruzi is capable of promoting metabolic disturbances currently considered as cardiovascular risk factors. Moreover, it has been observed that the protozoa can remain in adipose tissue and alter its immune endocrine functions. The aim of this study was to characterize the thickness of epicardial adipose tissue (EAT) in patients with chronic Chagas disease (CCD) concerning their cardiovascular metabolic risk profile compared with those without CCD. METHODS: A cross-sectional study was performed including T. cruzi seropositive individuals categorized according to a standard CCD classification and a matched seronegative control group. Complete clinical examination, metabolic laboratory tests and transthoracic echocardiography to assess cardiac function and to quantify EAT were performed. RESULTS: Fifty-five individuals aged 46.7±11.9 y, 34 with CCD and 21 in the control group, were included. The CCD group presented higher EAT thickness in relation to controls (4.54±1.28 vs 3.22±0.99 mm; p=0.001), which was significantly associated with the presence of insulin resistance (OR=3, 95% CI 1.58 to 5.73; p<0.001). This group presented lower levels of plasmatic adiponectin than controls, especially in those patients with EAT ≥4.5 mm (p=0.005) who also presented with heart failure more frequently (p=0.01). CONCLUSION: In patients with CCD, a higher EAT thickness is observed and is associated with an increased metabolic risk profile indicated mainly by insulin resistance.

Congenital chagas disease: Development and assessment of a specific IgM capture-based assay for diagnosis of transmission.

Transplacental transmission by Trypanosoma cruzi (T. cruzi) infection can be effectively treated if parasiticide drugs are administered as early as possible during childhood. Furthermore, an ideal situation would be to diagnose the infection near birth in order to avoid the loss of patients during the subsequent follow-up. These situation are desirable due to the maximum benefit of drugs in early stages which, consequently, implies a relevant contribution to eliminate mother-to-child transmission. However, available techniques for that purpose have limitations as being operator-dependent (microhematocrit), require several months follow-up (IgG detection) or specialized laboratories (PCR). In this study we propose to detect specific IgM antibodies (Ab) by developing a capture-based ELISA employing an improved antigen (Ag) to diagnose the transplacental transmission of T. cruzi, and in consequence, to enhance access to effective treatment. Firstly, a new chimera Ag (CP4) was obtained from the fusion of CP1 and CP3 protein, carrying FRA, SAPA, MAP, TSSAII/V/VI and TcD Ag from T. cruzi. Then, we optimized the assay by capturing IgM Ab with a polyclonal anti-IgM Ab and evaluating three Ag formulations to detect specific IgM bound. The formulations were formed as follows: i) F1: CP1 and CP3; ii) F2: CP1, CP3, B13 and P2ß; iii) F3: by CP4. Detection of Ab-binding Ag was carried out using an anti-His Ab since all Ag were expressed with a His-tag. The evaluation panel consisted of sera from vertically infected children under 1-year-old (6 younger than 15 days, 7 older) and samples from non-infected children of women with chronic Chagas Disease. The ELISA assay employing CP4 showed better performance with notable high sensitivity and specificity (92.3% and 93.9%, respectively). Positive and negative likelihood ratios of the test (15.2 and 0.082) suggest its potential clinical relevance in term of post-test probability of infection. In conclution, we developed a standardized and non-operator dependent test to detect specific anti-T. cruzi IgM Ab. Although increased sample size is needed for its validation, our results indicate that this capture-based technique employing CP4 Ag can certainly improve the diagnosis of connatal infection.

Seroprevalence of anti-SARS-CoV-2 IgG in asymptomatic and pauci-symptomatic people over a 5 month survey in Argentina / Seroprevalencia de anticuerpos IgG contra el SARS-CoV-2 en personas asintomáticas y paucisintomáticas en un estudio de 5 meses en Argentina / Soroprevalência de IgG contra SARS-CoV-2 em indivíduos assintomáticos e paucissintomáticos em um inquérito de 5 meses na Argentina

ABSTRACT Objective. To evaluate the seroprevalence of COVID-19 infection in pauci-symptomatic and asymptomatic people, the associated epidemiological factors, and IgG antibody kinetic over a 5-month period to get a better knowledge of the disease transmissibility and the rate of susceptible persons that might be infected. Methods. Seroprevalence was evaluated by a cross-sectional study based on the general population of Santa Fe, Argentina (non-probabilistic sample) carried out between July and November 2020. A subgroup of 20 seropositive individuals was followed-up to analyze IgG persistence. For the IgG anti-SARS-CoV-2 antibodies detection, the COVID-AR IgG® ELISA kit was used. Results. 3 000 individuals were included conforming asymptomatic and pauci-symptomatic groups (n=1 500 each). From the total sample, only 8.83% (n=265) presented reactivity for IgG anti-SARS-CoV-2. A significant association was observed between positive anti-SARS-CoV-2 IgG and a history of contact with a confirmed case; the transmission rate within households was approximately 30%. In the pauci-symptomatic group, among the seropositive ones, anosmia and fever presented an OR of 16.8 (95% CI 9.5-29.8) and 2.7 (95% CI 1.6-4.6), respectively (p <0.001). In asymptomatic patients, IgG levels were lower compared to pauci-symptomatic patients, tending to decline after 4 months since the symptoms onset. Conclusion. We observed a low seroprevalence, suggestive of a large population susceptible to the infection. Anosmia and fever were independent significant predictors for seropositivity. Asymptomatic patients showed lower levels of antibodies during the 5-month follow-up. IgG antibodies tended to decrease over the end of this period regardless of symptoms.

RESUMEN Objetivo. Evaluar la seroprevalencia de la infección por el virus causante de la COVID-19 en personas paucisintomáticas y asintomáticas, los factores epidemiológicos asociados y la cinética de los anticuerpos IgG durante un período de cinco meses para conocer mejor la transmisibilidad de la enfermedad y la tasa de personas susceptibles a estar infectadas. Métodos. Se evaluó la seroprevalencia mediante un estudio transversal basado en la población general de Santa Fe, Argentina (muestra no probabilística) llevado a cabo entre julio y noviembre del 2020. Se realizó un seguimiento de un subgrupo de 20 personas seropositivas para analizar la persistencia de los anticuerpos IgG. Para la detección de los anticuerpos IgG contra SARS-COV-2, se empleó el kit ELISA COVID-AR IgG®. Resultados. Hubo 3 000 participantes divididos en un grupo asintomático y un grupo paucisintomático (n=1 500 cada grupo). De la muestra total, solo 8,83% (n=265) presentó una reactividad de IgG contra el SARS-CoV-2. Se observó una asociación significativa entre anticuerpos IgG positivos contra el SARS-CoV-2 y antecedente de contacto con un caso confirmado. La tasa de transmisión en el hogar fue de 30% aproximadamente. En el grupo paucisintomático, entre las personas seropositivas, la anosmia y la fiebre presentaron un OR de 16,8 (IC 95% 9,5-29,8) y 2,7 (IC 95% 1,6-4,6), respectivamente (p <0,001). En los pacientes asintomáticos, los niveles de IgG fueron inferiores en comparación con los pacientes paucisintomáticos, con tendencia a la baja pasados cuatro meses desde la aparición de los síntomas. Conclusiones. Se observó una seroprevalencia baja, indicadora de una gran población susceptible a la infección. La anosmia y la fiebre fueron factores predictivos independientes de relevancia para la seropositividad. Los pacientes asintomáticos mostraron niveles inferiores de anticuerpos durante el seguimiento de cinco meses. Los anticuerpos IgG tendieron a disminuir hacia el final del período con independencia de los síntomas.

RESUMO Objetivo. Avaliar a soroprevalência de anticorpos contra a COVID-19 em indivíduos paucissintomáticos e assintomáticos, os fatores epidemiológicos associados e a cinética dos anticorpos da classe IgG em um período de 5 meses, visando aprimorar o conhecimento sobre a transmissibilidade da doença e a taxa de suscetíveis à infecção. Métodos. Inquérito transversal de soroprevalência realizado na população geral (amostra não probabilística) de Santa Fé, na Argentina, entre julho e novembro de 2020. Um subgrupo de 20 indivíduos soropositivos foi acompanhado para analisar a persistência de anticorpos IgG. O kit de ensaio imunoenzimático (ELISA) COVID-AR IgG® foi usado para a detecção de anticorpos IgG contra SARS-CoV-2. Resultados. A amostra compreendeu 3 000 indivíduos, divididos entre assintomáticos e paucissintomáticos (n = 1.500 por grupo). Deste total, somente 8,83% (n = 265) apresentaram reatividade, com a detecção de anticorpos IgG contra SARS-CoV-2. Observou-se uma associação significativa entre a presença de anticorpos IgG contra SARS-CoV-2 e histórico de contato com caso confirmado. A taxa de transmissão intradomiciliar foi de aproximadamente 30%. No grupo paucissintomático, entre os soropositivos, o odds ratio (OR) para anosmia foi de 16,8 (IC 95% 9,5-29,8), e para febre, 2,7 (IC 95% 1,6-4,6) (p <0,001). Os indivíduos assintomáticos apresentaram níveis de IgG mais baixos que os paucissintomáticos, com uma tendência de declínio após 4 meses do início dos sintomas. Conclusões. Observou-se uma soroprevalência baixa de anticorpos contra a COVID-19 na população estudada, o que indica um grande número de pessoas suscetíveis à infecção. Anosmia e febre foram preditores importantes independentes de soropositividade. Os assintomáticos apresentaram níveis mais baixos de anticorpos aos 5 meses de acompanhamento. Houve uma tendência de redução dos anticorpos IgG ao final deste período, independentemente da presença de sintomas.

Development and assessment of an improved recombinant multiepitope antigen-based immunoassay to diagnose chronic Chagas disease.

The use of chimeric molecules fusing several antigenic determinants is a promising strategy for the development of low-cost, standardized and reliable kits to determine specific antibodies. In this study, we designed and assessed a novel recombinant chimera that complements the performance of our previously developed chimera, CP1 [FRA and SAPA antigens (Ags)], to diagnose chronic Chagas disease. The new chimeric protein, named CP3, is composed of MAP, TcD and TSSAII/V/VI antigenic determinants. We compared the performance of both chimeric Ags using a panel of 67 Trypanosoma cruzi-reactive sera and 67 non-reactive ones. The sensitivity of CP3 vs CP1 was 100 and 90.2%, and specificity was 92.5 and 100%, respectively. The mixture of CP1 + CP3 achieved 100% of sensitivity and specificity. More importantly, an additional subset of 17 sera from patients with discordant results of conventional serological methods was analysed; the CP1 + CP3 mixture allowed us to accurately classify 14 of them with respect to IIF, the usual technique used in most of the reference centres. These results show an improved performance of the CP1 + CP3 mixture in comparison with enzyme-linked immunosorbent assay and indirect haemagglutination commercial assays.

Trans-sialidase-based vaccine candidate protects against Trypanosoma cruzi infection, not only inducing an effector immune response but also affecting cells with regulatory/suppressor phenotype.

Prophylactic and/or therapeutic vaccines have an important potential to control Trypanosoma cruzi (T. cruzi)infection. The involvement of regulatory/suppressor immune cells after an immunization treatment and T. cruzi infection has never been addressed. Here we show that a new trans-sialidase-based immunogen (TSf) was able to confer protection, correlating not only with beneficial changes in effector immune parameters, but also influencing populations of cells related to immune control. Regarding the effector response, mice immunized with TSf showed a TS-specific antibody response, significant delayed-type hypersensitivity (DTH) reactivity and increased production of IFN-γ by CD8+ splenocytes. After a challenge with T. cruzi, TSf-immunized mice showed 90% survival and low parasitemia as compared with 40% survival and high parasitemia in PBS-immunized mice. In relation to the regulatory/suppressor arm of the immune system, after T. cruzi infection TSf-immunized mice showed an increase in spleen CD4+ Foxp3+ regulatory T cells (Treg) as compared to PBS-inoculated and infected mice. Moreover, although T. cruzi infection elicited a notable increase in myeloid derived suppressor cells (MDSC) in the spleen of PBS-inoculated mice, TSf-immunized mice showed a significantly lower increase of MDSC. Results presented herein highlight the need of studying the immune response as a whole when a vaccine candidate is rationally tested.

Trans-sialidase overcomes many antigens to be used as a vaccine candidate against Trypanosoma cruzi.

AIM: The development of vaccines against Trypanosoma cruzi remains in an exploratory stage. Despite several antigen candidates have been evaluated, a comparison among the performance of the immunogens cannot be carried out because the available reports differ in formulations and infection model. In this work, we compared the protective capacity of seven T. cruzi antigens in the same model of five new antigens and two well-established candidates. Materials & methods: We evaluated highly immunogenic proteins that contain tandem repeats (FRA [flagelar repetitive protein], Tc3, Tc6); enzymes involved in metabolic pathways critical for parasite survival (cytosolic tryparedoxin peroxidase and tryparedoxin peroxidase); and enzymes involved in parasite invasion (trans-sialidase [TS] and cruzipain). All these antigens were formulated with Freund's adjuvant and protection against the parasite infection was assessed in BALB/c mice. RESULTS: Tc3, cytosolic tryparedoxin peroxidase, cruzipain and TS showed the best outcome after infection in survival level and parasitemia. According to these data, these groups were also assessed using the ISCOMATRIX™ adjuvant which is being used in clinical trials. CONCLUSION: Taken together, our results showed that the TS overcomes the performance of other antigens when the same model is employed, confirming that TS is a promising antigen that could be used as a vaccine against T. cruzi.

Antibody profiles induced by Trypanosoma cruzi in chagasic patients with previous or current exposure to mycobacteria.

Since the immune response mounted by the host to a particular microorganism might be influenced by the acquired immunological experience due to previous contact with other microorganisms, we performed a cross-sectional study to explore the pattern of Trypanosoma cruzi infection-related antibodies in T. cruzi-seropositive individuals presenting concomitant tuberculosis, or the antecedent of BCG vaccination. Sampled individuals were grouped as follows: patients with Chagas disease, not vaccinated with BCG, who further developed pulmonary tuberculosis; individuals with Chagas disease, BCG-vaccinated; and subjects with Chagas disease, presenting neither BCG scar nor tuberculosis disease. Non-vaccinated individuals or without tuberculosis, presented the highest values of anti-PH (P < 0.001), anti-FRA (P < 0.001), anti-p2ß (P = 0.0023) and anti-B13 (P < 0.001) antibodies. The present findings constitute the first demonstration of the potential influence of concomitant tuberculosis on Chagas disease.

Combined analysis of cross-reacting antibodies anti-ß1AR and anti-B13 in advanced stages of Chagas heart disease.

OBJECTIVE: Autoantibodies cross-reacting with the ß1 adrenergic receptor (anti-ß1AR and anti-p2ß) and cardiac myosin antigens (anti-B13) have been related to the pathogenesis of chronic Chagas heart disease (CCHD). Studies exploring their levels in different stages are scarce. We aimed to evaluate the relationship of these autoantibodies with the clinical profile of chronic patients, especially regarding their classificatory accuracy in severe presentation with heart failure. METHODS AND RESULTS: We conducted a cross-sectional study of 155 T. cruzi-seropositive patients and 26 age- and gender-matched healthy controls. They were categorised in three stages of CCHD. Serum antibodies were measured by specific immunoassays. Symptomatic individuals showed increased levels of anti-ß1AR and anti-B13, while anti-p2ß antibodies were similar between groups. A composite logistic regression model including anti-B13, anti-ß1AR antibody levels and age was able to predict systolic heart failure yielding an area under the curve of 83% (sensitivity of 67% and specificity of 89%). CONCLUSIONS: In our study, anti-ß1AR and anti-B13 antibodies were higher in individuals with chronic Chagas heart disease stage III, mainly in those with dilated cardiomyopathy associated with systolic heart failure. Logistic regression analysis showed that both antibodies were good predictors of severe CCHD. As well as being involved in disease progression, anti-ß1AR and anti-B13 antibodies may be used as a serum marker of poor prognosis in terms of heart compromise.

IgG Autoantibodies Induced by T. cruzi During Pregnancy: Correlation with Gravidity Complications and Early Outcome Assessment of the Newborns.

Objective The aim of the present research was to evaluate the correlation of vertically transmitted IgG antibodies induced by T. cruzi and newborn early outcome assessment, mainly birth weight and gestational age. Methods We performed a cross-sectional study with 183 pregnant women (64 with asymptomatic Chagas disease) and their newborns. Both were subjected to complete clinical examination. Peripheral parasitemia was assessed in mother and neonates by parasite detection through microscopic examination of the buffycoat from mother's peripheral and cord blood. Antibodies induced by T. cruzi, such as anti-FRA, anti-B13, anti-p2ß and anti-T. cruzi were assessed by immunoassay. Birth weight, general condition evaluation by APGAR Score and gestational age by Capurro Score, were determined in newborns. Results The rate of stillbirth background and pregnancy-induced hypertension were higher in patients with Chagas disease (p = 0.01 and p = 0.02, respectively). Parasitemia was detectable in 17 mothers and 4 newborns. The newborns of mothers with detectable parasitemia presented decreased gestational age (p = 0.006) and body weight (p = 0.04). Mostly all the mothers with Chagas disease and all their newborns have positive values of antibodies induced by T. cruzi; however, only anti-p2ß showed to be related to the presence of complication during pregnancy (OR 2.35, p = 0.036), and to low birth weight (OR 1.55, p = 0.02). Conclusions Low birth weight and decreased postnatal estimation of maturity were related to detectable parasitemia in the mother. Also, vertical transmission of T. cruzi-induced autoantibodies might have clinical implication in newborns given the negative association between anti-p2ß values and weight.

The potential influence of atherogenic dyslipidemia on the severity of chronic Chagas heart disease.

INTRODUCTION: chronic Chagas heart disease (CCHD) is the most common manifestation of American Trypanosomiasis, causing about 50,000 deaths annually. Several factors bear correlation with the severity of CCHD. However, to our knowledge, the assessment on the contribution of major cardiovascular risk factors (CRF), such as hypertension and atherogenic dyslipidemia (AD) to CCHD severity is scarce, despite their well-established role in coronary artery disease, heart failure and stroke. OBJECTIVE: to explore the potential relationship of blood pressure and AD with the clinical profile of patients with CCHD. METHODS: we performed a cross-sectional study in T. cruziseropositive patients categorized according to a standard CCHD classification. All individuals were subjected to complete clinical examination. Autoantibodies induced by T. cruzi were assessed by ELISA. RESULTS: we observed that Atherogenic index (AI) levels rose significantly in relation to the severity of the CCHD stage, with CCHD III cases showing the highest values of AI. Furthermore, those patients with globally dilated cardiomyopathy with reduced ejection fraction showed higher levels of AI. In regard to autoantibodies, anti-B13 also showed relation with the severity of the disease. CONCLUSION: we observed that AI correlated with CCHD stages and contributed, in association with anti-B13 antibodies and age, to the prediction of systolic heart failure.

The potential influence of atherogenic dyslipidemia on the severity of chronic Chagas heart disease / Influencia de la dislipidemia aterogénica en la gravedad de la miocardiopatía chagásica crónica

SUMMARY Introduction: chronic Chagas heart disease (CCHD) is the most common manifestation of American Trypanosomiasis, causing about 50,000 deaths annually. Several factors bear correlation with the severity of CCHD. However, to our knowledge, the assessment on the contribution of major cardiovascular risk factors (CRF), such as hypertension and atherogenic dyslipidemia (AD) to CCHD severity is scarce, despite their well-established role in coronary artery disease, heart failure and stroke. Objective: to explore the potential relationship of blood pressure and AD with the clinical profile of patients with CCHD. Methods: we performed a cross-sectional study in T. cruziseropositive patients categorized according to a standard CCHD classification. All individuals were subjected to complete clinical examination. Autoantibodies induced by T. cruzi were assessed by ELISA. Results: we observed that Atherogenic index (AI) levels rose significantly in relation to the severity of the CCHD stage, with CCHD III cases showing the highest values of AI. Furthermore, those patients with globally dilated cardiomyopathy with reduced ejection fraction showed higher levels of AI. In regard to autoantibodies, anti-B13 also showed relation with the severity of the disease. Conclusion: we observed that AI correlated with CCHD stages and contributed, in association with anti-B13 antibodies and age, to the prediction of systolic heart failure.

RESUMO Introducción: la miocardiopatía chagásica (MCC) es la manifestación más común de la tripanosomiasis americana, causando cerca de 50.000 muertes al año. Varios factores se asocian con la gravedad de MCC. Sin embargo, la evaluación de la contribución de los principales factores de riesgo cardiovascular (FRC), como la hipertensión y la dislipidemia aterogénica (DA), a la gravedad de la MCC es escasa, a pesar de su papel bien establecido en la enfermedad arterial coronaria, insuficiencia cardíaca y accidente cerebrovascular. Objetivo: explorar la posible relación de la presión arterial y la DA con el perfil clínico de los pacientes con MCC. Método: estudio transversal en pacientes con serología positiva para T. cruzi categorizados de acuerdo a la clasificación estándar de MCC. Se realizó en todos los pacientes un examen clínico-cardiológico completo. Los autoanticuerpos inducidos por T. cruzi se evaluaron mediante ELISA. Resultados: se observó que los niveles de índice aterogénico (IA) aumentaron significativamente en relación con la gravedad de la etapa de la MCC, siendo que los pacientes pertenecientes al grupo MCC III mostraron los más altos valores de IA. Por otra parte, los pacientes con miocardiopatía dilatada global con fracción de eyección reducida mostraron mayores niveles de IA. En lo que respecta a autoanticuerpos, anti-B13 también mostró relación con la gravedad de la enfermedad. Conclusión: observamos que el IA se correlacionó con las etapas de MCC y contribuyó, en asociación con anticuerpos anti-B13, a la predicción de insuficiencia cardíaca sistólica.

Función barorrefleja y variabilidad de la presión arterial evaluadas desde el consultorio clínico / Baroreflex function and blood pressure variability evaluated in the clinical consulting room

La variabilidad de la frecuencia cardíaca (FC) y de la presión arterial (PA) se evalúan por lo general mediante Holter y monitorización ambulatoria de la presión arterial (MAPA). Estos exámenes no se encuentran disponibles generalmente en el medio hospitalario. Objetivo: Evaluar los parámetros de la función barorrefleja determinada por electrocardiograma basal y durante la realización de la maniobra de Valsalva (MV), con los indicadores de variabilidad de FC por Holter y PA por MAPA. Métodos: Estudio transversal, observacional. Se incluyeron prospectivamente pacientes adultos, sin enfermedades ni utilización de fármacos que modifiquen la FC o la PA. Se realizó electrocardiograma (ECG) basal de 10 s. La respuesta cronotrópica se evaluó mediante MV estandarizada registrada en ECG. Se realizaron MAPA y Holter de 12 horas. Resultados: Se estudiaron 50 pacientes, observándose que el SDNN del ECG de 10 sy la variación de la FC intra/previa a la MV podrían resultar de utilidad para estimar el valor del SDNN del Holter, parámetro asociado con hipofunción barorrefleja y aumento de riesgo vascular. En cuanto a la PA, no pudo demostrarse mayor variabilidad de PA sistólica por MAPA en los pacientes con disminuciónde la respuesta cronotrópica. Conclusión: Indicadores simples de determinar en el consultorio clínico realizando ECG y MV podrían complementar la evaluación del riesgo cardiovascular y contribuira seleccionar aquellos pacientes en quienes sería conveniente efectuar un estudio de MAPA, tanto paradiagnóstico como para seguimiento...

In-hospital mortality risk factors in community acquired pneumonia: evaluation of immunocompetent adult patients without comorbidities.

OBJECTIVE: several scores were developed in order to improve the determination of community acquired pneumonia (CAP) severity and its management, mainly CURB-65 and SACP score. However, none of them were evaluated for risk assessment of in-hospital mortality, particularly in individuals who were non-immunosuppressed and/or without any comorbidity. In this regard, the present study was carried out. METHODS: we performed a cross-sectional study in 272 immunocompetent patients without comorbidities and with a diagnosis of CAP. Performance of CURB- 65 and SCAP scores in predicting in-hospital mortality was evaluated. Also, variables related to death were assessed. Furthermore, in order to design a model of in-hospital mortality prediction, sampled individuals were randomly divided in two groups. The association of the variables with mortality was weighed and, by multiple binary regression, a model was constructed in one of the subgroups. Then, it was validated in the other subgroup. RESULTS: both scores yielded a fair strength of agreement, and CURB-65 showed a better performance in predicting in-hospital mortality. In our casuistry, age, white blood cell counts, serum urea and diastolic blood pressure were related to death. The model constructed with these variables showed a good performance in predicting in-hospital mortality; moreover, only one patient with fatal outcome was not correctly classified in the group where the model was constructed and in the group where it was validated. CONCLUSION: our findings suggest that a simple model that uses only 4 variables, which are easily accessible and interpretable, can identify seriously ill patients with CAP.

In-hospital mortality risk factors in patients with ascites due to cirrhosis.

INTRODUCTION: ascites is one of the most common complications of cirrhosis associated with a high rate of mortality. Although several scores have been developed in order to assess the prognosis of the disease, they were designed for predicting liver transplantation requirements and mortality in the short term, but not while in hospital. The aim of this study was to weigh risk factors for in-hospital mortality in adult patients with ascites due to alcoholic cirrhosis. MATERIAL AND METHODS: we performed a cross-sectional study in 180 adult patients with diagnosis of cirrhosis with portal hypertension associated with high alcohol intake. The diagnosis of cirrhosis was made by liver echography and portal hypertension was defined by clinical features plus serum-ascites albumin gradient. Sampled individuals were subjected to complete clinical examination. Child Pugh and the MELD scores were applied in all the patients. RESULTS: nineteen patients died while in-hospital. Mortality was associated with increased levels of serum white blood cell, urea, creatinine, prolonged prothrombin time, aspartate aminotransferase and alanine aminotransferase. We conducted a multiple binary logistic to predict in-hospital mortality which yielded that serum urea, creatinine and prothrombin time made a significant contribution to prediction with an OR 14 (95% CI 12.8 - 16.7 p = 0.03), 2 (95% CI 0.5 - 3.47, p = 0.04), and 2 (95% CI 1.03 - 2.31, p = 0.01) linearly-related. CONCLUSIONS: our results suggest that acute renal failure and prolonged prothrombin time are predictors of in-hospital mortality in patients with portal hypertension due to alcoholic cirrhosis.

In-hospital mortality risk factors in community acquired pneumonia: evaluation of immunocompetent adult patients without comorbidities / Fatores de risco para mortalidade intra-hospitalar em pneumonia adquirida em comunidade: avaliação de pacientes imunocompetentes sem comorbidades

Summary Objective: several scores were developed in order to improve the determination of community acquired pneumonia (CAP) severity and its management, mainly CURB-65 and SACP score. However, none of them were evaluated for risk assessment of in-hospital mortality, particularly in individuals who were non-immunosuppressed and/or without any comorbidity. In this regard, the present study was carried out. Methods: we performed a cross-sectional study in 272 immunocompetent patients without comorbidities and with a diagnosis of CAP. Performance of CURB- 65 and SCAP scores in predicting in-hospital mortality was evaluated. Also, variables related to death were assessed. Furthermore, in order to design a model of in-hospital mortality prediction, sampled individuals were randomly divided in two groups. The association of the variables with mortality was weighed and, by multiple binary regression, a model was constructed in one of the subgroups. Then, it was validated in the other subgroup. Results: both scores yielded a fair strength of agreement, and CURB-65 showed a better performance in predicting in-hospital mortality. In our casuistry, age, white blood cell counts, serum urea and diastolic blood pressure were related to death. The model constructed with these variables showed a good performance in predicting in-hospital mortality; moreover, only one patient with fatal outcome was not correctly classified in the group where the model was constructed and in the group where it was validated. Conclusion: our findings suggest that a simple model that uses only 4 variables, which are easily accessible and interpretable, can identify seriously ill patients with CAP .

Resumo Objetivo: diversos escores de gravidade da pneumonia adquirida em comunidade (PAC) foram desenvolvidos com o intuito de melhorar o manejo clínico, em especial os escores CURB-65 e SCAP. Contudo, nenhum dos dois foi avaliado para determinar o risco de morte intra- hospitalar, principalmente em pacientes imunocompetentes e/ou sem comorbidades. Diante disso, propusemo- nos a analisar a utilidade dos escores para prever a mortalidade intra-hospitalar e estudar as variáveis associadas ao desfecho fatal. Métodos: desenvolvemos um trabalho transversal com 272 pacientes imunocompetentes, sem comorbidades e com diagnóstico de PAC. Foi avaliada a eficácia dos escores CURB-65 e SCAP em prever a mortalidade durante a internação. Foram estudadas as variáveis relacionadas a este desfecho. Por fim, a amostra foi dividida em dois subgrupos com o objetivo de desenvolver um modelo de avaliação do risco de morte em um subgrupo, validando-o no outro. Resultados: ambos os escores apresentaram pobre concordância de classificação da gravidade para PAC. O escore CURB-65 mostrou melhor desempenho na avaliação do risco de morte. Em nossa amostra, idade, contagem de glóbulos brancos, ureia sérica e pressão arterial diastólica foram as variáveis que se associaram à mortalidade. O modelo desenvolvido com essas variáveis mostrou eficácia muito boa para prever o desfecho fatal. Inclusive, somente um paciente no grupo de desenvolvimento do modelo e outro no grupo de validação foram classificados de modo incorreto. Conclusão: nossos resultados sugerem que com um modelo de quatro variáveis, de fácil acesso e interpretação, foi possível identificar pacientes gravemente enfermos com PAC. .