From Psoriasis to Psoriatic Arthritis: Ultrasound Insights Connecting Psoriasis with Subclinical Musculoskeletal Inflammation and the Path to Psoriatic Arthritis.

PURPOSE OF REVIEW: This review summarizes the literature about the transition from psoriasis to psoriatic arthritis (PsA), focusing on musculoskeletal ultrasound (MSUS) for detecting subclinical inflammation and its role in diagnosis and triage of high-risk patients. RECENT FINDINGS: MSUS effectively detects subclinical musculoskeletal inflammation in patients with psoriasis; however, some of these lesions are non-specific and can be found in healthy individuals. Preliminary evidence suggest that subclinical sonographic findings may predict progression to PsA in psoriasis patients. MSUS can also improve referrals' accuracy and its integration in the PsA classification criteria may improve early PsA detection. MSUS is a valuable tool for detecting subclinical abnormalities in psoriasis patients, which indicate an increased likelihood of progressing to PsA. Its integration into referral protocols and clinical use could improve PsA diagnosis. We propose an MSUS-inclusive algorithm for PsA referrals and triage, which requires validation. The potential of early intervention in reducing PsA progression in psoriasis patients with subclinical inflammation remains to be established.

Negative predictive value of procalcitonin to rule out bacterial respiratory co-infection in critical covid-19 patients.

BACKGROUND: Procalcitonin (PCT) and C-Reactive Protein (CRP) are useful biomarkers to differentiate bacterial from viral or fungal infections, although the association between them and co-infection or mortality in COVID-19 remains unclear. METHODS: The study represents a retrospective cohort study of patients admitted for COVID-19 pneumonia to 84 ICUs from ten countries between (March 2020-January 2021). Primary outcome was to determine whether PCT or CRP at admission could predict community-acquired bacterial respiratory co-infection (BC) and its added clinical value by determining the best discriminating cut-off values. Secondary outcome was to investigate its association with mortality. To evaluate the main outcome, a binary logistic regression was performed. The area under the curve evaluated diagnostic performance for BC prediction. RESULTS: 4635 patients were included, 7.6% fulfilled BC diagnosis. PCT (0.25[IQR 0.1-0.7] versus 0.20[IQR 0.1-0.5]ng/mL, p<0.001) and CRP (14.8[IQR 8.2-23.8] versus 13.3 [7-21.7]mg/dL, p=0.01) were higher in BC group. Neither PCT nor CRP were independently associated with BC and both had a poor ability to predict BC (AUC for PCT 0.56, for CRP 0.54). Baseline values of PCT<0.3ng/mL, could be helpful to rule out BC (negative predictive value 91.1%) and PCT≥0.50ng/mL was associated with ICU mortality (OR 1.5,p<0.001). CONCLUSIONS: These biomarkers at ICU admission led to a poor ability to predict BC among patients with COVID-19 pneumonia. Baseline values of PCT<0.3ng/mL may be useful to rule out BC, providing clinicians a valuable tool to guide antibiotic stewardship and allowing the unjustified overuse of antibiotics observed during the pandemic, additionally PCT≥0.50ng/mL might predict worsening outcomes.

Clinical characteristics, systemic complications, and in-hospital outcomes for patients with COVID-19 in Latin America. LIVEN-Covid-19 study: A prospective, multicenter, multinational, cohort study.

PURPOSE: The COVID-19 pandemic has spread worldwide, and almost 396 million people have been infected around the globe. Latin American countries have been deeply affected, and there is a lack of data in this regard. This study aims to identify the clinical characteristics, in-hospital outcomes, and factors associated with ICU admission due to COVID-19. Furthermore, to describe the functional status of patients at hospital discharge after the acute episode of COVID-19. MATERIAL AND METHODS: This was a prospective, multicenter, multinational observational cohort study of subjects admitted to 22 hospitals within Latin America. Data were collected prospectively. Descriptive statistics were used to characterize patients, and multivariate regression was carried out to identify factors associated with severe COVID-19. RESULTS: A total of 3008 patients were included in the study. A total of 64.3% of patients had severe COVID-19 and were admitted to the ICU. Patients admitted to the ICU had a higher mean (SD) 4C score (10 [3] vs. 7 [3)], p<0.001). The risk factors independently associated with progression to ICU admission were age, shortness of breath, and obesity. In-hospital mortality was 24.1%, whereas the ICU mortality rate was 35.1%. Most patients had equal self-care ability at discharge 43.8%; however, ICU patients had worse self-care ability at hospital discharge (25.7% [497/1934] vs. 3.7% [40/1074], p<0.001). CONCLUSIONS: This study confirms that patients with SARS CoV-2 in the Latin American population had a lower mortality rate than previously reported. Systemic complications are frequent in patients admitted to the ICU due to COVID-19, as previously described in high-income countries.

Structure and Contact Angle in Sessile Droplets of Binary Mixtures of Lennard-Jones Chains: A Molecular Dynamics Study.

Molecular dynamics simulations were carried out to investigate cylindrical droplets consisting of binary mixtures of Lennard-Jones (LJ) fluids in contact with a solid substrate. The droplets are composed of mixtures of the monomeric LJ fluid plus linear-tangent chains of 2, 10, 20, and 30 segments per chain that interact through a harmonic potential and the spherically truncated and shifted potential Lennard-Jones. The solid surface was modeled as a semi-infinite platinum substrate with an FCC structure that interacts with the fluid by means of a LJ 9-3 potential. We place emphasis on the effect of mixing a monomeric LJ fluid with heavy components on the contact angle and on the droplet structure, especially in the liquid-solid region. The density profiles of the droplets reveal a strong discrete layering of the fluid in the vicinity of the solid-liquid interface. The layering is more pronounced at low temperatures and for mixtures of short chains (symmetric mixtures). The ordering of the fluid was much less intense for fluids of long chains (asymmetric mixtures), and some cases even show gas enrichment at the solid-liquid interface. Enrichment at the vapor-liquid interfaces and density inversion can also be observed. However, these effects are not as marked as in planar interfaces. The contact angle between the droplet and the substrate is calculated by fitting an ellipse to the vapor-liquid interface defined by the Gibbs dividing surface. In general, an increment in the concentration of the heavy component and a reduction of the temperature resulted in an increase of the contact angle, which in turn disfavored the wetting of the droplet.

Interfacial properties of binary mixtures of Lennard-Jones chains in planar interfaces by molecular dynamics simulation.

Binary mixtures of fully flexible linear tangent chains composed of bonded Lennard-Jones interaction sites (monomers) were studied using the molecular dynamics simulation in the NVT ensemble. Their interfacial properties were investigated in planar interfaces by direct simulation of an explicit liquid film in equilibrium with its vapor. A method for the calculation of long-range interactions in inhomogeneous fluids was implemented to take into account the potential truncation effects. Surface tension and the pressure tensor were calculated via the classical Irving-Kirkwood method; vapor pressure, orthobaric densities, density profiles, and Gibbs relative adsorption of the volatile component with respect to the heavy component were also obtained. The properties were studied as a function of the temperature, molar concentration of the heavy component, and the asymmetry of the mixture. According to the results of this work, the temperature loses influence on the surface tension, vapor pressure, and Gibbs relative adsorption curves as the molecular length of the heavy component increases. This suggests that the universal behavior observed in pure fluids of Lennard-Jones chains also holds for binary mixtures. The contribution of the long-range interactions turned out to account for about 60%, 20%, and 10% of the surface tension, vapor pressure, and orthobaric density final values, respectively. This contribution was even larger at high temperatures and for large molecules. Strong enrichment of the volatile component at the interface was observed in the asymmetric mixtures. One of these mixtures even showed a barotropic effect at elevated pressures and a class III phase behavior.

Burden of invasive pneumococcal disease (IPD) over a 10-year period in Bogotá, Colombia.

BACKGROUND: Invasive pneumococcal disease (IPD) is the leading cause of infectious death worldwide. This study aimed to describe the epidemiology of IPD and the impact of pneumococcal conjugate vaccine-10 (PCV-10) over a 10-year period in Bogotá, Colombia. METHODS: This was a laboratory-based surveillance study of Streptococcus pneumoniae isolated from patients with IPD from 82 hospitals over 10 years in Bogotá, Colombia. Data were compared between two periods: 2007-2011 (before the introduction of PCV-10) and 2012-2017 (after the introduction of PCV-10). RESULTS: In total, 1670 patients with IPD were included in the study between 2007 and 2017. Between 2007 and 2011, the most common serotypes were 14, 1, 6B, 6A and 3. Between 2012 and 2017, the most common serotypes were 19A, 3, 14 and 1. A decrease in the incidence of IPD, particularly in children aged 0-4 years, was noted after the introduction of PCV-10. Importantly, this reduction in incidence was not observed in patients aged ≥50 years. CONCLUSIONS: The IPD burden in Bogotá remained stable between 2007 and 2017. The incidence of IPD decreased in children but not in older adults. The introduction of PCV-10 led to a change in the most prevalent serotypes to serotypes that are not included in PCV-10.

Results of a global, patient-based survey assessing the impact of psoriatic arthritis discussed in the context of the Psoriatic Arthritis Impact of Disease (PsAID) questionnaire.

BACKGROUND: Psoriatic arthritis (PsA) is a chronic immune-mediated inflammatory musculoskeletal disease, manifesting as peripheral arthritis, enthesitis, dactylitis, spondylitis, and skin and nail psoriasis. A core set of domains for measuring the impact of PsA has been developed, including pain, patient global assessment, physical function, health-related quality of life (HRQoL), and fatigue. To understand the impact of PsA on health domains from a patient's perspective, a global survey was developed and results reported in the context of the 12-item Psoriatic Arthritis Impact of Disease (PsAID-12) questionnaire. METHODS: An online patient-based global survey was conducted by The Harris Poll in Australia, Brazil, Canada, France, Spain, Taiwan, the UK, and the US between November 2, 2017 and March 12, 2018. Eligible patients were ≥ 18 years old with a diagnosis of PsA for > 1 year, had visited a rheumatologist/dermatologist in the past 12 months and reported using ≥ 1 synthetic/biologic disease-modifying antirheumatic drug for PsA. Patients reported on PsA severity and symptoms, and the impact of PsA on HRQoL. After survey completion, responses were aligned with PsAID health domains. Descriptive statistics and chi-square tests were conducted. RESULTS: This analysis included 1286 patients from eight countries. Most patients (97%) reported musculoskeletal symptoms relating to PsA in the past year. Common moderate/major impacts of PsA were on physical activity (78%), ability to perform certain activities (76%), work productivity (62%), and career path (57%). Skin/nail symptoms occurred in 80% of patients. Overall, 69% of patients reported that PsA had a moderate/major impact on emotional/mental wellbeing, 56% on romantic relationships/intimacy, and 44% on relationships with family and friends. Social impacts included emotional distress (58%), social shame or disapproval (32%), and ceased participation in social activities (45%). Over half of all patients experienced unusual fatigue over the past 12 months (52%). The health domains that patients reported as being impacted by PsA aligned with life impact domains of the patient-derived PsAID health domains. CONCLUSION: These results highlight the impact of PsA on multiple health domains from a patient perspective that should be considered during shared decision-making processes between healthcare providers and patients.

Imiquimod-loaded nanoarchaeosomes as a promising immunotherapy against Trypanosoma cruzi infection.

The purpose of this study was to evaluate the efficacy of imiquimod-containing nanovesicles prepared with lipids extracted from the hyperhalophile archaebacterium Halorubrum tebenquichense (nanoARC-IMQ) to induce protection against Trypanosoma cruzi infection. The therapeutic efficacy of archaeolipid nanovesicles was assessed in an experimental murine model of acute infection with T. cruzi. The administration of nanoARQ-IMQ prevented mortality as compared to infected untreated animals, reduced parasitemia levels and diminished myocardial and musculoskeletal lesions in mice infected with a lethal strain of T. cruzi. Our findings suggest that the immunotherapy with nanoARC-IMQ has potential to limit the progression of Chagas disease.

A simple, rapid and low cost reversed-phase dispersive liquid-liquid microextraction for the determination of Na, K, Ca and Mg in biodiesel.

In this work a method based on reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) as sample preparation for the extraction and preconcentration of Na, K, Ca and Mg in biodiesel samples was developed. The analytes determination was performed by flame atomic absorption spectrometry (FAAS), operating in emission mode for Na and K and in absorption mode for Ca and Mg. The extraction/preconcentration step of the analytes was performed by using a mixture of dispersant and extractant solvents (isopropanol and HNO3, respectively) and the aqueous phase containing the analytes was separated by centrifugation. Some parameters such as sample mass, type and volume of dispersant and extractant solutions, HNO3 concentration (extraction solution), use of ultrasound, centrifugation time and temperature were evaluated. During the optimization of RP-DLLME, biodiesel samples were spiked with a multi-element biodiesel B100 (Conostan®) with final concentration of 1.0 µg g-1 of the analytes. Analytes determination was performed by FAAS using external calibration with aqueous reference solutions. The limits of quantification (LOQ) for Na, K, Ca and Mg were 0.04; 0.02; 0.05 and 0.08 µg kg respectively. The accuracy was evaluated by recovery tests, which ranged from 93.9% to 108.1%, with relative standard deviation lower than 3% for all analytes. Then, the proposed method was applied for analytes determination in five biodiesel samples produced from different raw materials. Comparing to conventional methods for elements determination in biodiesel (e.g., dilution with organic solvent, sample digestion, etc.), RP-DLLME combined to FAAS is simple, low cost, low reagents consumption and provides LOQs values significantly below compared to the limits established in the legislation for these elements in biodiesel.

Athenolide A, a New Steroidal Lactone from the Leaves of Athenaea martiana (Solanaceae) Determined by Means of HPLC-HR-MS-SPE-NMR Analysis.

Athenaea (Solanaceae) is an endemic genus belonging to the Brazilian Atlantic Rainforest. Recently, botanical investigations suggested the re-evaluation of the generic status of the genus Athenaea as a synonym of Aureliana. In this study, the first investigation of the Athenaea genus performed on Athenaea martiana by means of HPLC-HR-MS-SPE-NMR combined with high-resolution radical scavenging profile led to identification of several phenolic acids as radical scavengers: protocatechuic acid (1), 4-hydroxybenzoic acid (2), caffeic acid (3), vanillic acid (4), and ferulic acid (6). Additional analysis revealed a new steroidal lactone, named athenolide A (9). Their structures were elucidated by extensive use of NMR spectroscopy as well as HR-MS. Chemotaxonomic considerations based on these results supported the chemical relationships between the Athenaea and Aureliana genera, in agreement with the recent botanical findings.

Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill.

Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid (1) and 3-indolecarboxylic acid (6) associated with radical scavenging activity, and the amide alkaloids N-trans-p-coumaroyloctopamine (3), N-trans-p-feruloyloctopamine (4), N-trans-p-coumaroyltyramine (8) and N-trans-p-feruloyltyramine (9) correlated with α-glucosidase inhibitory activity as well as radical scavenging activity. Further analysis revealed a new lactone, methyl 5-ethyl-4-hydroxy-5-methyl-2-oxotetrahydro-2H-pyran-4-carboxylate (7) and a new steroid with a rare F ring (11). Corchorifatty acid B (12) was reported for the first time in the Solanaceae family. Their structures were elucidated by extensive use of 1D and 2D NMR spectroscopy as well as HRMS analysis.

Dendritic nanoparticles for cutaneous drug delivery--testing in human skin and reconstructed human skin.

Dendritic nanoparticles have been developed with auspicious properties like high loading capacity for guest molecules, low polydispersity and tunable end groups. Demonstrating increased cellular uptake and bypassed efflux transporters, dendritic nanoparticles may offer new treatment options for therapy-resistant diseases. New core-shell architectures address the drawbacks of initial approaches. Especially tecto-dendrimers, bearing low-radii dendrimers on the surface of a bigger dendrimer, as well as the core-multishell architectures with an alkyl inner shell and a monomethylpoly(ethylene glycol) outer shell, gained interest for dermatotherapy. Moreover, the integration of e.g. pH labile groups into dendritic nanoparticles may offer triggered drug release. However, before declaring dendritic nanoparticles as an ultimate drug delivery system for skin penetration, dendritic nanoparticles need to prove their efficacy and safety in non-clinical, and subsequently in clinical studies. Here, we review major characteristics of human skin, and thus target structures for topical drug delivery systems. Focusing on the use as in vitro test system, we summarize the features of reconstructed human skin. Since drug delivery systems are intended to be applied to diseased skin, we additionally review latest insights into disease-related changes in the highly prevalent skin diseases such as atopic dermatitis, and cutaneous squamous cell carcinoma, as well as in their respective human cell-based skin disease models. We will conclude with the proposal of an integrated test strategy to promote the introduction of dendritic nanoparticles into medicinal products.

Enhanced photodynamic leishmanicidal activity of hydrophobic zinc phthalocyanine within archaeolipids containing liposomes.

In this work, the in vitro anti-Leishmania activity of photodynamic liposomes made of soybean phosphatidylcholine, sodium cholate, total polar archaeolipids (TPAs) extracted from the hyperhalophile archaea Halorubrum tebenquichense and the photosensitizer zinc phthalocyanine (ZnPcAL) was compared to that of ultradeformable photodynamic liposomes lacking TPAs (ZnPcUDLs). We found that while ZnPcUDLs and ZnPcALs (130 nm mean diameter and -35 mV zeta potential) were innocuous against promastigotes, a low concentration (0.01 µM ZnPc and 7.6 µM phospholipids) of ZnPcALs irradiated at a very low-energy density (0.2 J/cm(2)) eliminated L. braziliensis amastigotes from J774 macrophages, without reducing the viability of the host cells. In such conditions, ZnPcALs were harmless for J774 macrophages, HaCaT keratinocytes, and bone marrow-derived dendritic cells. Therefore, topical photodynamic treatment would not likely affect skin-associated lymphoid tissue. ZnPcALs were extensively captured by macrophages, but ZnPcUDLs were not, leading to 2.5-fold increased intracellular delivery of ZnPc than with ZnPcUDLs. Despite mediating low levels of reactive oxygen species, the higher delivery of ZnPc and the multiple (caveolin- and clathrin-dependent plus phagocytic) intracellular pathway followed by ZnPc would have been the reason for the higher antiamastigote activity of ZnPcALs. The leishmanicidal activity of photodynamic liposomal ZnPc was improved by TPA-containing liposomes.

The correlation between carotid artery atherosclerosis and clinical ischemic heart disease in lupus patients.

AIM: The extent of subclinical atherosclerosis can be assessed by ultrasound measurement of carotid intima-media thickness (cIMT) and total plaque area (TPA). We aimed to investigate the correlation between measures of atherosclerosis as documented on imaging studies of the carotid vasculature and clinical coronary artery disease (CAD) in systemic lupus erythematosus (SLE). METHODS: The study patients were recruited from the University of Toronto prospective cohort of SLE patients. Patients who had a history of CAD were compared to those without CAD. TPA and cIMT were measured using high-resolution optimized ultrasound systems. Logistic regression models were used to investigate the strength of association between ultrasound measures of atherosclerosis and CAD. The strength of association as expressed by odds ratio (OR) was compared between TPA and cIMT. RESULTS: A total of 103 SLE patients were analyzed (27 patients with a history of CAD). Carotid IMT correlated only moderately with TPA (r = 0.43, p < 0.001). Both measures were significantly associated with the presence of CAD. However, TPA showed a stronger association than cIMT (OR 9.55 vs. 2.02, respectively). TPA was also more strongly associated with dyslipidemia and hypertension compared to cIMT. CONCLUSIONS: In SLE patients, cIMT correlates only moderately with TPA, suggesting that they measure different phenotypes of atherosclerosis. Carotid TPA correlated better than cIMT with cardiovascular risk factors and CAD, suggesting that it may serve as a better tool for the investigation of atherosclerosis in SLE.

Damage in lupus patients--what have we learned so far?

With the improvement of survival of systemic lupus erythematosus (SLE) patients, prevention of organ damage has become a major goal in the management of these patients. The need for a reliable tool for assessment of cumulative damage over time led to the development of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI) that allowed a standardized measurement of damage and facilitated research in the field. Damage accumulates over the course of the disease; however, some patients do not accrue any damage even after many years. Damage accrues at a higher rate among patients with more active disease, highlighting the importance of prompt control of disease manifestations. However, medications administered to control disease activity, particularly corticosteroids, can also result in organ damage, emphasizing the need for adjustment of these agents as soon as disease is under control.

Thromboelastometric detection of clotting Factor XIII deficiency in cardiac surgery patients.

AIM(S): In this article, we aimed to investigate plasma Factor XIII levels after extracorporeal circulation in cardiac surgery by thromboelastometric detection, as extracorporeal circulation causes various coagulation disorders due to the exposure of blood to artificial surfaces, inflammatory induction and mechanical destruction of platelets and coagulation factors, which may particularly affect factors with long half-lives, such as Factor XIII. BACKGROUND: Since transfusion algorithms are often empirical and laboratory analysis of Factor XIII plasma levels may not be available 24 h a day, bed-side testing using rotational thromboelastometry (ROTEM) could offer a splendid option to define the cause of excessive peri-operative bleeding disorders in general and Factor XIII levels in particular in a timely manner and thus facilitating exact substitution therapy. METHODS: In this trial, we investigated 25 cardiac surgery patients with extracorporeal bypass times over 100 min. Standard laboratory and ROTEM analyses were performed post-operatively at the time of intensive care unit admission and 6 h later. We implemented EXTEM with additional Factor XIII (teenTEM) as additional test by adding 0·625 IU Factor XIII to standard EXTEM reagents. RESULTS: In this observational study, we could not demonstrate a correlation between Factor XIII and MCFEXTEM , CFTEXTEM or MLEXTEM . Neither Factor XIII plasma levels nor MCFEXTEM could predict blood loss. In accordance with previous findings, we were able to demonstrate increased maximum clot firmness (MCF), decreased clot formation time and decreased maximum lysis by adding Factor XIII in vitro (teenTEM vs EXTEM) indicating an improvement in the coagulation process. As shown before, we also found a strong correlation between MCF and platelet and fibrinogen plasma levels. CONCLUSION: In summary, 'teenTEM' test does not seem to detect Factor XIII deficient patients in cardiac surgery. Furthermore, post-operative blood loss could not be predicted neither by ROTEM nor by laboratory analysis of Factor XIII. In vitro administration of Factor XIII appears to improve laboratory measures of haemostasis.

The functional MICA-129 polymorphism is associated with skin but not joint manifestations of psoriatic disease independently of HLA-B and HLA-C.

A methionine/valine polymorphism at amino acid 129 of the major histocompatibility complex class I chain-related gene A (MICA-129) categorizes alleles into strong and weak binders of the natural killer (NK) and T-cell receptor NKG2D. We investigated whether MICA-129 is differentially associated with skin and joint manifestations of psoriatic disease (PsD) independently of human leukocyte antigen (HLA)-C and HLA-B in patients and controls from Toronto and St. John's. The MICA-129 methionine (Met) allele, particularly Met/Met homozygosity, was strongly associated with both cutaneous psoriasis (PsC) and psoriatic arthritis (PsA) independently of HLA-B and HLA-C in Toronto patients, and was also associated with PsA in St. John's patients, but with no additional effect of Met/Met homozygosity. No association remained after adjustment for HLA alleles in St. John's patients. MICA-129 was not associated with PsA when compared with PsC. We conclude that MICA-129 is a marker of skin manifestations of PsD that is independent of HLA class I in Toronto patients.

Archaeosomes display immunoadjuvant potential for a vaccine against Chagas disease.

Archaeosomes (ARC), vesicles made from lipids extracted from Archaea, display strong adjuvant properties. In this study, we evaluated the ability of the highly stable ARC formulated from total polar lipids of a new Halorubrum tebenquichense strain found in Argentinean Patagonia, to act as adjuvant for soluble parasite antigens in developing prophylactic vaccine against the intracellular protozoan T. cruzi, the etiologic agent of Chagas disease. We demonstrated for the first time that C3H/HeN mice subcutaneously immunized with trypanosomal antigens entrapped in these ARC (ARC-TcAg) rapidly developed higher levels of circulating T. cruzi antibodies than those measured in the sera from animals receiving the antigen alone. Enhanced humoral responses elicited by ARC-TcAg presented a dominant IgG2a antibody isotype, usually associated with Th1-type immunity and resistance against T. cruzi. More importantly, ARC-TcAg-vaccinated mice displayed reduced parasitemia during early infection and were protected against an otherwise lethal challenge with the virulent Tulahuén strain of the parasite. Our findings suggest that, as an adjuvant, H. tebenquichense-derived ARC may hold great potential to develop a safe and helpful vaccine against this relevant human pathogen.