Adverse Events Associated with Nifurtimox Treatment for Chagas Disease in Children and Adults

Targeting ESE3/EHF With Nifurtimox Inhibits CXCR2+ Neutrophil Infiltration and Overcomes Pancreatic Cancer Resistance to Chemotherapy and Immunotherapy

BACKGROUND & AIMS

Because pancreatic cancer responds poorly to chemotherapy and immunotherapy, it is necessary to identify novel targets and compounds to overcome resistance to treatment.

METHODS

This study analyzed genomic single nucleotide polymorphism sequencing, single-cell RNA sequencing, and spatial transcriptomics. Ehf-knockout mice, KPC (LSL-KrasG12D/+, LSL-Trp53R172H/+ and Pdx1-Cre) mice, CD45.1+ BALB/C nude mice, and CD34+ humanized mice were also used as subjects. Multiplexed immunohistochemistry and flow cytometry were performed to investigate the proportion of tumor-infiltrated C-X-C motif chemokine receptor 2 (CXCR2)+ neutrophils. In addition, multiplexed cytokines assays and chromatin immunoprecipitation assays were used to examine the mechanism.

RESULTS

The TP53 mutation-mediated loss of tumoral EHF increased the recruitment of CXCR2+ neutrophils, modulated their spatial distribution, and further induced chemo- and immunotherapy resistance in clinical cohorts and preclinical syngeneic mice models. Mechanistically, EHF deficiency induced C-X-C motif chemokine ligand 1 (CXCL1) transcription to enhance in vitro and in vivo CXCR2+ neutrophils migration. Moreover, CXCL1 or CXCR2 blockade completely abolished the effect, indicating that EHF regulated CXCR2+ neutrophils migration in a CXCL1-CXCR2-dependent manner. The depletion of CXCR2+ neutrophils also blocked the in vivo effects of EHF deficiency on chemotherapy and immunotherapy resistance. The single-cell RNA-sequencing results of PDAC treated with Nifurtimox highlighted the therapeutic significance of Nifurtimox by elevating the expression of tumoral EHF and decreasing the weightage of CXCL1-CXCR2 pathway within the microenvironment. Importantly, by simultaneously inhibiting the JAK1/STAT1 pathway, it could significantly suppress the recruitment and function of CXCR2+ neutrophils, further sensitizing PDAC to chemotherapy and immunotherapies.

CONCLUSIONS

The study demonstrated the role of EHF in the recruitment of CXCR2+ neutrophils and the promising role of Nifurtimox in sensitizing pancreatic cancer to chemotherapy and immunotherapy.

Enteric nervous system regeneration and functional cure of experimental digestive Chagas disease with trypanocidal chemotherapy

Digestive Chagas disease (DCD) is an enteric neuropathy caused by Trypanosoma cruzi infection. There is a lack of evidence on the mechanism of pathogenesis and rationales for treatment. We used a female C3H/HeN mouse model that recapitulates key clinical manifestations to study how infection dynamics shape DCD pathology and the impact of treatment with the front-line, anti-parasitic drug benznidazole. Curative treatment 6 weeks post-infection resulted in sustained recovery of gastrointestinal transit function, whereas treatment failure led to infection relapse and gradual return of DCD symptoms. Neuro/immune gene expression patterns shifted from chronic inflammation to a tissue repair profile after cure, accompanied by increased cellular proliferation, glial cell marker expression and recovery of neuronal density in the myenteric plexus. Delaying treatment until 24 weeks post-infection led to partial reversal of DCD, suggesting the accumulation of permanent tissue damage over the course of chronic infection. Our study shows that murine DCD pathogenesis is sustained by chronic T. cruzi infection and is not an inevitable consequence of acute stage denervation. The risk of irreversible enteric neuromuscular tissue damage and dysfunction developing highlights the importance of prompt diagnosis and treatment. These findings support the concept of treating asymptomatic, T. cruzi-infected individuals with benznidazole to prevent DCD development.

Chagas disease

Chagas disease persists as a global public health problem due to the high morbidity and mortality burden. Despite the possibility of a cure and advances in transmission control, epidemiological transformations, such as urbanisation and globalisation, and the emerging importance of oral and vertical transmission mean that Chagas disease should be considered an emerging disease, with new cases occurring worldwide. Important barriers to diagnosis, treatment, and care remain, resulting in repressed numbers of reported cases, which in turn leads to inadequate public policies. The validation of new diagnostic tools and treatment options is needed, as existing tools pose serious limitations to access to health care. Integrated models of surveillance, with community and intersectional participation, embedded in the concept of One Health, are essential for control. In addition, mitigation strategies for the main social determinants of health, including difficulties imposed by migration, are important to improve access to comprehensive health care in a globalised scenario.

Green Synthetic Strategies and Pharmaceutical Applications of Thiazine and its Derivatives: An Updated Review

Thiazines are a sizable class of organic heterocycles that are notable for their skeletal versatility and relative chemical simplicity, making them among the most flexible sources of biologically active compounds. The term "green synthesis" refers to implementing energy-efficient procedures for the nature-friendly production of materials and chemicals using green solvents, catalysts, and suitable reaction conditions. Considering the importance of green chemistry and the outstanding therapeutic profile of thiazines, the present work was designed to review the recent advances in green chemistry-based synthetic strategies of thiazine and its derivatives. The green synthetic approaches, including microwave-assisted, ultrasound-assisted, and various other synthetic methods for thiazine and its derivatives, were discussed and generalized. In addition, applications of thiazine and its derivatives in pharmaceutical sciences were explained with examples of marketed drugs.The discussed sustainable synthetic methods for thiazines and their derivatives could be useful in developing other medicinally important lead molecules. They could also aid in developing new synthetic schemes and apparatuses that may simplify chemical manufacturing processes and enable novel reactions with minimal by-products while questing for optimal, green solvents. This review can help anyone interested in this fascinating class of heterocycles to make decisions about selecting targets and tasks for future research.

Long-term cardiology outcomes in children after early treatment for Chagas disease, an observational study

BACKGROUND

Parasite persistence after acute infection with Trypanosoma cruzi is an important factor in the development of Chagas disease (CD) cardiomyopathy. Few studies have investigated the clinical effectiveness of CD treatment through the evaluation of cardiological events by long term follow-up of treated children. Cardiological evaluation in children is challenging since features that would be diagnosed as abnormal in an adult's ECG may be normal, age-related findings in a pediatric ECG trace. The objective was to evaluate cardiac involvement in patients with Chagas disease with a minimum follow-up of 6 years post-treatment.

METHODOLOGY

A descriptive study of a cohort of pediatric patients with CD treated with benznidazole (Bz) or nifurtimox (Nf) was conducted. Children (N = 234) with at least 6 years post CD treatment followed at the Parasitology and Chagas Service, Buenos Aires Children's Hospital (Argentina) were enrolled. By convenience sampling, children who attended a clinical visit between August 2015 and November 2019 were also invited to participate for additional cardiovascular studies like 24-hour Holter monitoring and speckle-tracking 2D echocardiogram (STE). Benznidazole was prescribed in 171 patients and nifurtimox in 63 patients. Baseline parasitemia data was available for 168/234 patients. During the follow-up period, alterations in routine ECG were observed in 11/234 (4.7%, 95% CI [2-7.4%]) patients. In only four patients, with complete right bundle branch block (cRBBB) and left anterior fascicular block (LAFB), ECG alterations were considered probably related to CD. During follow-up, 129/130 (99%) treated patients achieved persistent negative parasitemia by qPCR. Also decrease in T.cruzi antibodies titers was observed in all patients and negative seroconversion occurred in 123/234 (52%) patients.

CONCLUSIONS

A low incidence of cardiological lesions related to CD was observed in patients treated early for pediatric CD. This suggests a protective effect of parasiticidal treatment on the development of cardiological lesions and highlights the importance of early treatment of infected children.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04090489.

Effectiveness of Nifurtimox in the Treatment of Chagas Disease: a Long-Term Retrospective Cohort Study in Children and Adults

Chagas disease (ChD), caused by Trypanosoma cruzi, has a global prevalence due to patient migration. However, despite its worldwide distribution, long-term follow-up efficacy studies with nifurtimox (NF) are scarce and have been conducted with only small numbers of patients. A retrospective study of a large cohort of ChD treated children and adults with NF. Treatment response was evaluated by clinical, parasitological, and serological after-treatment evaluation. A total of 289 patients were enrolled, of which 199 were children and 90 adults. At diagnosis, 89.6% of patients were asymptomatic. Overall, all symptomatic patients showed clinical improvement. At baseline, parasitemia was positive in 130 of 260 (50%) patients. All but one adult patient had cleared their parasitemia by the end of treatment. That patient was considered a treatment failure. Median follow-up time for children was 37.7 months, with an interquartile range of (IQR_25–75 12.2 to 85.3), and for adults was 14.2 months (IQR_25–75, 1.9 to 33.8). After treatment, a decrease of T. cruzi antibodies and seroconversion were observed in 34.6% of patients. The seroconversion profile showed that, the younger the patient, the higher the rate of seroconversion (log rank test; P value, <0.01). At least 20% seroreduction at 1 year follow-up was observed in 33.2% of patients. Nifurtimox was highly effective for ChD treatment. Patients had excellent treatment responses with fully resolved symptoms related to acute T. cruzi infection. Clearance of parasitemia and a decrease in T. cruzi antibodies were observed as markers of treatment response. This study reinforces the importance of treating patients during childhood since the treatment response was more marked in younger subjects. (This protocol was registered at ClinicalTrials.gov under registration number NCT04274101).

Trypanocidal effect of alcoholic extract of Castanedia santamartensis (Asteraceae) leaves is based on altered mitochondrial function

The deficit of effective treatments for Chagas disease has led to searching for new substances with therapeutic potential. Natural products possess a wide variety of chemical structural motifs and are thus a valuable source of diverse lead compounds for the development of new drugs. Castanedia santamartensis is endemic to Colombia, and local indigenous communities often use it to treat skin sores from leishmaniasis; however, its mechanism of action against the infective form of Trypanosoma cruzi has not been determined. Thus, we performed chemical and biological studies of two alcoholic leaf extracts of C. santamartensis to identify their active fractions and relate them to a trypanocidal effect and evaluate their mechanism of action. Alcoholic extracts were obtained through cold maceration at room temperature and fractionated using classical column chromatography. Both ethanolic and methanolic extracts displayed activity against T. cruzi. Chemical studies revealed that kaurenoic acid was the major component of one fraction of the methanolic extract and two fractions of the ethanolic extract of C. santamartensis leaves. Moreover, caryophyllene oxide, kaurenol, taraxasterol acetate, pentadecanone, and methyl and ethyl esters of palmitate, as well as a group of phenolic compounds, including ferulic acid, caffeic acid, chlorogenic acid, myricetin, quercitrin, and cryptochlorogenic acid were identified in the most active fractions. Kaurenoic acid and the most active fractions CS400 and CS402 collapsed the mitochondrial membrane potential in trypomastigotes, demonstrating for the first time the likely mechanism against T. cruzi, probably due to interactions with other components of the fractions.

7-Aryl-7-deazapurine 3'-deoxyribonucleoside derivative as a novel lead for Chagas' disease therapy: in vitro and in vivo pharmacology

Background

The protozoan Trypanosoma cruzi is auxotrophic for purines and causes Chagas’ disease (CD), a neglected illness affecting >6 million people. Combining the 3-deoxyribofuranose part of cordycepin with the modified purine ring of a nucleoside ‘hit’ led to the discovery of 4-amino-5-(4-chlorophenyl)-N7-(3′-deoxy-β-d-ribofuranosyl)-pyrrolo[2,3-d]pyrimidine (Cpd1), revealing promising anti-T. cruzi activity.

Objectives

To further evaluate Cpd1 in vitro and in vivo to fully assess its therapeutic potential against CD, covering cell culture sterilization through washout assays, drug combination with benznidazole and long-term administration in T. cruzi-infected mice.

Results

Although less susceptible to Cpd1 than amastigotes, trypomastigotes present an impaired capacity to successfully establish intracellular infection of cardiac cultures. Combination of benznidazole with Cpd1 indicated no interaction (additive effect) (FIC index = 0.72) while administration to mice at one-tenth of the optimal dose (2.5 mg/kg and 10 mg/kg for Cpd1 and benznidazole, respectively) suppressed parasitaemia but failed to avoid mortality. Long-term treatment (60 days) gave a rapid drop of the parasitaemia (>98% decline) and 100% mice survival but only 16% cure. In vitro washout experiments demonstrated that although parasite release into the supernatant of infected cardiac cultures was reduced by >94%, parasite recrudescence did occur after treatment.

Conclusions

Parasite recrudescence did occur after treatment corroborating the hypothesis of therapeutic failure due to subpopulations of dormant forms and/or genetic factors in persister parasites involved in natural drug resistance.

A Rapid Review on the Efficacy and Safety of Pharmacological Treatments for Chagas Disease

Chagas disease remains a neglected tropical disease, causing significant burden in the Americas and countries that receive immigrants from endemic nations. Current pharmaceutical treatments are suboptimal, not only varying drastically in efficacy, depending on the stage of disease, but also presenting significant risk of adverse events. The objective of this review is to provide a timely update on the efficacy and safety of current trypanocidals. Eligible studies published from January 2015 to December 2020 were retrieved by one reviewer from six electronic databases. Ana-lysis was done with review management software and risk of bias was assessed using tools appropriate for the type of study (i.e., experimental or observational). Thirteen studies (10 observational and three RCTs) were included in the analysis. All 13 studies tested Benznidazole (BNZ) or Nifurtimox (NFX), and two studies also tested Posaconazole (POS) or E1224 (Ravucanazole). BNZ was found to be the most efficacious trypanocidal drug compared to Nifurtimox, POS, and E1224; it also resulted in the highest percentage of adverse effects (AEs) and treatment discontinuation due to its toxicity. Adults experienced higher frequency of neurological AEs while taking BNZ or NFX compared to children. Children had a higher frequency of general AEs compared to adults while taking BNZ. Overall, BNZ is still the most efficacious, but development of new, less toxic drugs is paramount for the quality of life of patients. Studies testing combination therapies and shorter regimens are needed, as is the devising of better clinical parameters and laboratory biomarkers to evaluate treatment efficacy. Considering the variability in methodology and reporting of the studies included in the present analysis, we offer some recommendations for the improvement and replicability of clinical studies investigating pharmacological treatment of Chagas disease. These include full disclosure of methodology, standardization of outcome measures, and always collecting and reporting data on both the efficacy of trypanocidals and on safety outcomes.

Chagas Cardiomyopathy: From Romaña Sign to Heart Failure and Sudden Cardiac Death

Despite nearly a century of research and accounting for the highest disease burden of any parasitic disease in the Western Hemisphere, Chagas disease (CD) is still a challenging diagnosis, primarily due to its poor recognition outside of Latin America. Although initially considered endemic to Central and South America, globalization, urbanization, and increased migration have spread the disease worldwide in the last few years, making it a significant public health threat. The international medical community's apparent lack of interest in this disease that was previously thought to be geographically restricted has delayed research on the complex host-parasite relationship that determines myocardial involvement and its differential behavior from other forms of cardiomyopathy, particularly regarding treatment strategies. Multiple cellular and molecular mechanisms that contribute to degenerative, inflammatory, and fibrotic myocardial responses have been identified and warrant further research to expand the therapeutic arsenal and impact the high burden attributed to CD. Altogether, cardiac dysautonomia, microvascular disturbances, parasite-mediated myocardial damage, and chronic immune-mediated injury are responsible for the disease's clinical manifestations, ranging from asymptomatic disease to severe cardiac and gastrointestinal involvement. It is crucial for healthcare workers to better understand CD transmission and disease dynamics, including its behavior on both its acute and chronic phases, to make adequate and evidence-based decisions regarding the disease. This review aims to summarize the most recent information on the epidemiology, pathogenesis, clinical presentation, diagnosis, screening, and treatment of CD, emphasizing on Chagasic cardiomyopathy's (Ch-CMP) clinical presentation and pathobiological mechanisms leading to sudden cardiac death.