A phase II trial of nifurtimox combined with topotecan and cyclophosphamide for refractory or relapsed neuroblastoma and medulloblastoma.

Children with relapsed/refractory (R/R) neuroblastoma (NB) and medulloblastoma (MB) have poor outcomes. We evaluated the efficacy of nifurtimox (Nfx) in a clinical trial for children with R/R NB and MB. Subjects were divided into three strata: first relapse NB, multiply R/R NB, and R/R MB. All patients received Nfx (30 mg/kg/day divided TID daily), Topotecan (0.75 mg/m2 /dose, days 1-5) and Cyclophosphamide (250 mg/m2 /dose, days 1-5) every 3 weeks. Response was assessed after every two courses using International Neuroblastoma Response Criteria and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. One hundred and twelve eligible patients were enrolled with 110 evaluable for safety and 76 evaluable for response. In stratum 1, there was a 53.9% response rate (CR + PR), and a 69.3% total benefit rate (CR + PR + SD), with an average time on therapy of 165.2 days. In stratum 2, there was a 16.3% response rate, and a 72.1% total benefit rate, and an average time on study of 158.4 days. In stratum 3, there was a 20% response rate and a 65% total benefit rate, an average time on therapy of 105.0 days. The most common side effects included bone marrow suppression and reversible neurologic complications. The combination of Nfx, topotecan and cyclophosphamide was tolerated, and the objective response rate plus SD of 69.8% in these heavily pretreated populations suggests that this combination is an effective option for patients with R/R NB and MB. Although few objective responses were observed, the high percentage of stabilization of disease and prolonged response rate in patients with multiply relapsed disease shows this combination therapy warrants further testing.

Selected Aspects of the Analytical and Pharmaceutical Profiles of Nifurtimox.

Nifurtimox is a nitroheterocyclic drug employed for treatment of trypanosomiases (Chagas disease and West African sleeping sickness); its use for certain cancers has also been assessed. Despite having been in the market for over 50 years, knowledge of nifurtimox is still fragmentary and incomplete. Relevant aspects of the chemistry and biology of nifurtimox are reviewed to summarize the current knowledge of this drug. These comprise its chemical synthesis and the preparation of some analogues, as well as its chemical degradation. Selected physical data and physicochemical properties are also listed, along with different approaches toward the analytical characterization of the drug, including electrochemical (polarography, cyclic voltammetry), spectroscopic (ultraviolet-visible, nuclear magnetic resonance, electron spin resonance), and single crystal X-ray diffractometry. The array of polarographic, ultraviolet-visible spectroscopic, and chromatographic methods available for the analytical determination of nifurtimox (in bulk drug, pharmaceutical formulations, and biological samples), are also presented and discussed, along with chiral chromatographic and electrophoretic alternatives for the separation of the enantiomers of the drug. Aspects of the drug likeliness of nifurtimox, its classification in the Biopharmaceutical Classification System, and available pharmaceutical formulations are detailed, whereas pharmacological, chemical, and biological aspects of its metabolism and disposition are discussed.

Trypanosoma cruzi Mitochondrial Peroxiredoxin Promotes Infectivity in Macrophages and Attenuates Nifurtimox Toxicity.

Trypanosoma cruzi is the causative agent of Chagas disease which is currently treated by nifurtimox (NFX) and benznidazole (BZ). Nevertheless, the mechanism of action of NFX is not completely established. Herein, we show the protective effects of T. cruzi mitochondrial peroxiredoxin (MPX) in macrophage infections and in response to NFX toxicity. After a 3-day treatment of epimastigotes with NFX, MPX content increased (2.5-fold) with respect to control, and interestingly, an MPX-overexpressing strain was more resistant to the drug. The generation of mitochondrial reactive species and the redox status of the low molecular weight thiols of the parasite were not affected by NFX treatment indicating the absence of oxidative stress in this condition. Since MPX was shown to be protective and overexpressed in drug-challenged parasites, non-classical peroxiredoxin activity was studied. We found that recombinant MPX exhibits holdase activity independently of its redox state and that its overexpression was also observed in temperature-challenged parasites. Moreover, increased holdase activity (2-fold) together with an augmented protease activity (proteasome-related) and an enhancement in ubiquitinylated proteins was found in NFX-treated parasites. These results suggest a protective role of MPX holdase activity toward NFX toxicity. Trypanosoma cruzi has a complex life cycle, part of which involves the invasion of mammalian cells, where parasite replication inside the host occurs. In the early stages of the infection, macrophages recognize and engulf T. cruzi with the generation of reactive oxygen and nitrogen species toward the internalized parasite. Parasites overexpressing MPX produced higher macrophage infection yield compared with wild-type parasites. The relevance of peroxidase vs. holdase activity of MPX during macrophage infections was assessed using conoidin A (CA), a covalent, cell-permeable inhibitor of peroxiredoxin peroxidase activity. Covalent adducts of MPX were detected in CA-treated parasites, which proves its action in vivo. The pretreatment of parasites with CA led to a reduced infection index in macrophages revealing that the peroxidase activity of peroxiredoxin is crucial during this infection process. Our results confirm the importance of peroxidase activity during macrophage infection and provide insights for the relevance of MPX holdase activity in NFX resistance.

Nifurtimox Hampered the Progression of Astroglioma In vivo Via Manipulating the AKT-GSK3ß axis.

BACKGROUND: Astroglioma, one major form of brain tumors, has remained principally tough to handle for decades, due to the complexity of tumor pathology and the poor response to chemo- and radio-therapies. METHODS: Our previous study demonstrated that nifurtimox could regulate the signaling axis of AKT-GSK3ß in various tumor types including the astroglioma U251 cells. Intriguingly, earlier case studies suggested that nifurtimox could possibly permeate the blood brain barrier and arrest neuroblastoma in the brain. These observations jointly encouraged us to explore whether nifurtimox would hinder the growth of astroglioma in vivo. RESULTS: Our results exhibited that nifurtimox could competently hinder the development of astroglioma in the mouse brain as compared to temozolomide, the first line of drug for brain tumors. Meanwhile the surviving rate, as well as the body-weight was dramatically upregulated upon nifurtimox treatment, as compared to that of temozolomide. These findings offered nifurtimox as a better alternative drug in treating astroglioma in vivo. CONCLUSION: Persistently, the manipulation of the signaling axis of AKT-GSK3ß in astroglioma was found in line with earlier findings in neuroblastoma when treated with nifurtimox.

Enfermedad de chagas congénito: presentación de caso clínico / Congenital chagas disease: case report

El agente etiológico de la enfermedad de Chagas es un protozoario parásito (Tripano-soma Cruzi) que causa una infección aguda y crónica, en humanos. La extensión del daño varía de acuerdo a las cepas parasita-rias y características individuales del hués-ped; puede causar incapacidad y muerte. Han sido descritas diferentes vías de infec-ción: vectorial, transfusional, accidental, digestiva y congénita. Esta última vía de la infección depende de dos indicadores bási-cos, la prevalencia de gestantes chagásicas e incidencia de la transmisión vertical. El diagnóstico presenta un desafío en aquellos lugares del país en donde, si bien la enfer-medad es considerada endémica, no se realiza actualmente el screening obligatorio en la embarazada. Es importante saber que el tratamiento antes del primer año de vida tiene una excelente respuesta y evita secue-las crónicas que pueden ser invalidantes en etapa adulta...(AU)

Synergic Effect of Allopurinol in Combination with Nitroheterocyclic Compounds against Trypanosoma cruzi.

Combination therapy has gained attention as a possible strategy for overcoming the limitations of the present therapeutic arsenal for Chagas disease. The aim of this study was to evaluate the effect of allopurinol in association with nitroheterocyclic compounds on infection with the Y strain of Trypanosoma cruzi The in vitro effect of allopurinol plus benznidazole or nifurtimox on intracellular amastigotes in infected H9c2 cells was assessed in a 72-h assay. The interactions were classified as synergic for both allopurinol-nifurtimox (sums of fractional inhibitory concentrations [∑FICs] = 0.49 ± 0.08) and allopurinol-benznidazole (∑FICs = 0.48 ± 0.09). In the next step, infected Swiss mice were treated with allopurinol at 30, 60, and 90 mg/kg of body weight and with benznidazole at 25, 50, and 75 mg/kg in monotherapy and in combination at the same doses; as a reference treatment, another group of animals received benznidazole at 100 mg/kg. Allopurinol in monotherapy led to a smaller or nil effect in the reduction of parasite load and mortality rate. Treatment with benznidazole at suboptimal doses induced a transient suppression of parasitaemia with subsequent relapse in all animals treated with 25 and 50 mg/kg and in 80% of those that received 75 mg/kg. Administration of the drugs in combination significantly increased the cure rate to 60 to 100% among mice treated with benznidazole at 75 mg/kg plus 30, 60, or 90 mg/kg of allopurinol. These results show a positive interaction between allopurinol and benznidazole, and since both drugs are commercially available, their use in combination may be considered for the assessment in the treatment of Chagas disease patients.

Therapeutic drug monitoring of benznidazole and nifurtimox: a systematic review and quality assessment of published clinical practice guidelines

Abstract The pharmacological management of adults with chronic-phase Chagas disease is challenging despite it being the recent focus of extensive research. One of the challenges in the current clinical practice guidelines (CPGs) landscape is the existence of non-evidence-based recommendations for the use of laboratory tests in treatment monitoring. This study aimed to systematically assess the quality and consistency of recommendations of CPGs on the pharmacological management of adults with chronic-phase Chagas disease. Systematic literature searches were conducted in MEDLINE, EMBASE, SciELO and Google to identify all published CPGs relevant to the pharmacological management of Chagas disease, between January 2010 and March 2016. Three independent reviewers assessed the quality of each CPG using the Appraisal of Guidelines Research and Evaluation (AGREE) II instrument. A total of five CPGs were included and the overall quality of the guidelines for therapeutic drug monitoring of Chagas disease was moderate-to-low. There was considerable variation in the quality of the CPGs across the AGREE II domains. The domains of scope/purpose, stakeholder involvement, and clarity of presentation were rated well, and the domains of applicability and editorial independence received poor ratings. This review showed that the methodological quality of CPGs for Chagas disease was generally inappropriate, and there was no explicit link between the best available evidence and current recommendations.

Dipyridamole potentiated the trypanocidal effect of nifurtimox and improved the cardiac function in NMRI mice with acute chagasic myocarditis

BACKGROUND As chronic Chagas disease does not have a definitive treatment, the development of alternative therapeutic protocols is a priority. Dipyridamole (DPY) is an alternative to counteract the pathophysiological phenomena involved in Chagas cardiomyopathy. OBJECTIVE To evaluate the therapeutic efficacy of DPY associated with nifurtimox (Nfx) in epimastigote axenic cultures and in mice with acute Chagas disease. METHODS NMRI adult male mice were divided into nine groups: three healthy and six Trypanosoma cruzi-infected groups. Mice received vehicle, Nfx or DPY, alone or combined. The doses assayed were Nfx 10 and 40 mg/kg and DPY 30 mg/kg. The treatment efficacy was evaluated by clinical, electrocardiographic, parasitological, biochemical and histopathological methods. FINDINGS In vitro, DPY and Nfx had a trypanocidal effect with IC50 values of 372 ± 52 and 21.53 ± 2.13 µM, respectively; DPY potentiated the Nfx effect. In vivo, Nfx (40 mg/kg) with or without DPY had a therapeutic effect, which was reflected in the 84-92% survival rate and elimination of parasitaemia and heart tissue amastigotes. Nfx (10 mg/kg) had a subtherapeutic effect with no survival and persistence of amastigotes, inflammation and fibrosis in heart tissue; adding DPY increased the survival rate to 85%, and all tested parameters were significantly improved. MAIN CONCLUSION DPY has a trypanocidal effect in vitro and enhances the Nfx therapeutic effect in an in vivo murine model.

Terapia de Resgate com Nifurtimox e Dipiridamol na Miocardite Chagásica Aguda Grave com Insuficiência Cardíaca em Camundongos NMRI / Rescue Therapy with Nifurtimox and Dipyridamole for Severe Acute Chagas Myocarditis with Congestive Heart Failure in NMRI Albino Mice

Fundamento: A doença de Chagas é um problema de saúde global, sendo necessário o desenvolvimento de novos protocolos terapêuticos. Nosso grupo demonstrou recentemente que o nifurtimox associado ao dipiridamol tem efeitos curativos em camundongos com doença de Chagas aguda. Neste estudo, avaliamos o efeito deste protocolo terapêutico em camundongos chagásicos com insuficiência cardíaca. Objetivo: Avaliar se o nifurtimox e o dipiridamol são úteis no tratamento de resgate em camundongos com miocardite chagásica aguda com insuficiência cardíaca. Métodos: Foram divididos em três grupos 42 camundongos com miocardite chagásica aguda e insuficiência cardíaca congestiva: Controle Chagas (n = 11); Nif-Dip, tratados com nifurtimox e dipiridamol (n = 14); e Nif-Dip-Insuficiência Cardíaca, tratados com nifurtimox e dipiridamol, associados com digoxina, furosemida e captopril (n = 17). As doses de nifurtimox e dipiridamol foram de 40 e 30mg/kg/dia, respectivamente, durante 6 semanas. Os camundongos foram submetidos a avaliações clínicas, eletrocardiográficas, hemoparasitológicas e histopatológicas. Resultados: Observou-se menor mortalidade no Grupo Nif-Dip (n = 4; 28,57%) em relação ao Controle Chagas (n = 6; 54,54%) e ao Nif-Dip-Insuficiência Cardíaca (n = 9; 52,9%). Clinicamente, os camundongos tratados com nifurtimox e dipiridamol aumentaram o peso corporal e melhoraram a insuficiência cardíaca, sem mostrar esplenomegalia. Nestes grupos, foram erradicadas as parasitemias e os parasitas teciduais; a fibrose, a miocitólise, o infiltrado de células inflamatórias e os mastócitos diminuíram. Os distúrbios de repolarização, os intervalos QRS e o QT prolongados, o aumento da amplitude da onda S e a dissociação atrioventricular foram revertidos pelo tratamento. Conclusão: O tratamento com nifurtimox e dipiridamol pode ser usado no resgate em camundongos com doença chagásica aguda grave, já que o nifurtimox teve atividade tripanocida, e o dipiridamole potenciou seu efeito. O dipiridamol seria útil na insuficiência cardíaca chagásica

Background: Chagas disease is a global health problem; therefore, the development of new therapeutic protocols is necessary. Our group recently demonstrated that nifurtimox associated with dipyridamole has curative effects in mice with acute Chagas disease. In this study, we assess the effect of this therapeutic protocol in chagasic mice with heart failure. Objective: To evaluate whether nifurtimox and dipyridamole are useful to rescue mice with severe acute chagasic myocarditis with heart failure. Methods: 42 mice with acute chagasic myocarditis and congestive heart failure were divided into three groups: control chagas (n = 11), Nif-Dip treated with nifurtimox and dipyridamole (n = 14) and Nif-Dip-heart failure treated with nifurtimox and dipyridamole associated with digoxin, furosemide, and captopril (n = 17). Nifurtimox and dipyridamole doses were 40 and 30 mg/kg/day, respectively, for 6 weeks. Mice underwent clinical, electrocardiographic, hemoparasitological and histopathological assessments. Results: Lower mortality in Nif-Dip (28.57%; n = 4) compared to control chagas (54.54%; n = 6) and Nif-Dip-heart failure (52.9%; n = 9) was observed. Clinically, nifurtimox and dipyridamole-treated mice increased body weight and improved heart failure without splenomegaly. In these groups, parasitemia and tissue parasites were eradicated; fibrosis, myocytolysis, inflammatory cell infiltrate and mast cells decreased. Repolarization disorders, prolonged QRS and QT intervals, increase of S wave amplitude and atrioventricular dissociation were reversed by the treatment. Conclusion: Nifurtimox with dipyridamole can rescue NMRI mice from severe acute chagas disease, as nifurtimox showed trypanocidal activity and dipyridamole potentiated its effect. Dipyridamole would be useful in chagasic heart failure

Chagas congénito de segunda generación en Uruguay: Primer caso sintomático descrito en el país / Second generation congenital Chagas disease in Uruguay: First symptomatic case described in the country

El Chagas congénito se produce cuando la embarazada infectada trasmite el parásito al feto, situación que puede suceder en cualquier estadio de la enfermedad y momento del embarazo. Es el único mecanismo de trasmisión presente actualmente en Uruguay, con una incidencia cercana al 4%. La mayoría de los neonatos infectados nacen asintomáticos y un 10% al 40% presentan síntomas que son indistinguibles de otras infecciones de trasmisión vertical. La prematurez, el bajo peso, la hepatoesplenomegalia y las alteraciones hematológicas son los síntomas más frecuentes. El diagnóstico representa un desafío en aquellos lugares del país en donde, si bien la enfermedad era considerada endémica, no se realiza actualmente el screening obligatorio de la embarazada. Se describe un lactante procedente de Paysandú, de medio socioeconómico deficitario, que fue pretérmino severo y que presentó al nacer alteraciones hematológicas de las tres series y hepatoesplenomegalia, lo cual motivó múltiples estudios. Sin embargo, no se sospechó la enfermedad hasta los 5 meses de vida, cuando volvió a ingresar por otra patología. Se confirmó la infección a los 9 meses mediante tres técnicas serológicas diferentes. Se indicó tratamiento con nifurtimox por 2 meses y a los 26 y 36 meses de vida presentó serología negativa. Consideramos importante tener alto índice de sospecha de la enfermedad en neonatos con signos de infección congénita y sin serología materna que la descarte. Es importante saber que el tratamiento antes del primer año de vida tiene una excelente respuesta y evita secuelas crónicas que pueden ser invalidantes en etapa adulta.

Congenital Chagas disease occurs when an infected pregnant woman transmits the parasite to the fetus, a situation that can happen at any stage of disease and time of pregnancy. It is the only transmission mechanism currently present in Uruguay, with an incidence close to 4%. Most infected infants are born asymptomatic and 10 to 40% have symptoms that are indistinguishable from other infections’ vertical transmission. Prematurity, low birth weight, hepatosplenomegaly and hematological disorders are the most common symptoms. Diagnosis is a challenge in those areas where there is no current compulsory screening for pregnant women in spite of the disease being considered endemic. The study presents the case of an infant from Paysandú, coming from a low socio-economic environment, which was a severe preterm, and presented hematologic disorders of the three series at birth and hepatosplenomegaly, which caused many studies. However, there was no suspicion of the disease until the infant was five months old when re-entering by other pathology. Infection at nine months is confirmed by three different serological techniques. Nifurtimox therapy is indicated for two months and at twenty six and thirty six months of life the patient presents negative serology. A high level of suspicion is needed in order to diagnose the disease in infants with signs of congenital infection without maternal serology. It is important to know that treatment before the first year of life has excellent response and prevents chronic sequelae that can be disabling in adulthood.

Chagas disease and transfusion medicine: a perspective from non-endemic countries.

In the last decades, increasing international migration and travel from Latin America to Europe have favoured the emergence of tropical diseases outside their "historical" boundaries. Chagas disease, a zoonosis endemic in rural areas of Central and South America represents a clear example of this phenomenon. In the absence of the vector, one of the potential modes of transmission of Chagas disease in non-endemic regions is through blood and blood products. As most patients with Chagas disease are asymptomatic and unaware of their condition, in case of blood donation they can inadvertently represent a serious threat to the safety of the blood supply in non-endemic areas. Since the first cases of transfusion-transmitted Chagas disease were described in the last years, non-endemic countries began to develop ad hoc strategies to prevent and control the spread of the infection. United States, Spain, United Kingdom and France first recognised the need for Trypanosoma cruzi screening in at-risk blood donors. In this review, we trace an up-to-date perspective on Chagas disease, describing its peculiar features, from epidemiological, pathological, clinical and diagnostic points of view. Moreover, we describe the possible transmission of Chagas disease through blood or blood products and the current strategies for its control, focusing on non-endemic areas.

Hepatotoxicity in mice of a novel anti-parasite drug candidate hydroxymethylnitrofurazone: a comparison with Benznidazole.

BACKGROUND: Treatment of Chagas disease, caused by Trypanosoma cruzi, relies on nifurtimox and benznidazole (BZL), which present side effects in adult patients, and natural resistance in some parasite strains. Hydroxymethylnitrofurazone (NFOH) is a new drug candidate with demonstrated trypanocidal activity; however, its safety is not known. METHODS: HepG2 cells dose response to NFOH and BZL (5-100 µM) was assessed by measurement of ROS, DNA damage and survival. Swiss mice were treated with NFOH or BZL for short-term (ST, 21 d) or long-term (LT, 60 d) periods. Sera levels of cellular injury markers, liver inflammatory and oxidative stress, and fibrotic remodeling were monitored. RESULTS: HepG2 cells exhibited mild stress, evidenced by increased ROS and DNA damage, in response to NFOH, while BZL at 100 µM concentration induced >33% cell death in 24 h. In mice, NFOH ST treatment resulted in mild-to-no increase in the liver injury biomarkers (GOT, GPT), and liver levels of inflammatory (myeloperoxidase, TNF-α), oxidative (lipid peroxides) and nitrosative (3-nitrotyrosine) stress. These stress responses in NFOH LT treated mice were normalized to control levels. BZL-treated mice exhibited a >5-fold increase in GOT, GPT and TNF-α (LT) and a 20-40% increase in liver levels of MPO activity (ST and LT) in comparison with NFOH-treated mice. The liver inflammatory infiltrate was noted in the order of BZL>vehicle≥NFOH and BZL>NFOH≥vehicle, respectively, after ST and LT treatments. Liver fibrotic remodeling, identified after ST treatment, was in the order of BZL>vehicle>NFOH; lipid deposits, indicative of mitochondrial dysfunction and in the order of NFOH>vehicle>BZL were evidenced after LT treatment. CONCLUSIONS: NFOH induces mild ST hepatotoxicity that is normalized during LT treatment in mice. Our results suggest that additional studies to determine the efficacy and toxicity of NFOH are warranted.

Experiencia terapéutica en un centro para la enfermedad de Chagas / Therapeutic experience in a Chagas disease center

American Trypanosomiasis or Chagas Disease is a major public health problem, endemic in the American continent since prehistoric times. Its natural course is towardschronicity in the immunocompetent host, often leading to severe cardiopathy or bowelinvolvement. Pharmacologic therapy is restricted to two drugs and only one of themis currently available in Chile. Both have poor effectiveness in the chronic stages ofthe disease and cause frequent adverse reactions. Many physicians avoid their use,despite published evidences about the usefulness. We herein report the experienceof our Center in the treatment of Chronic Chagas Disease in adults using the drugnifurtimox, emphasizing its degree of acceptability and its secondary effects.

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease / Avaliação do tratamento tripanossomicida em coorte de adultos chagásicos crônicos através de técnicas sorológicas convencionais e ELISA-F29

This work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

Este trabalho comparou os tempos de soroconversão negativos obtidos pela sorologia convencional (CS) e teste ELISA-F29 em uma coorte de pacientes chagásicos crônicos tratados com nifurtimox ou benznidazol. Um estudo retrospectivo foi realizado com soro preservado de 66 adultos chagásicos assintomáticos com acompanhamento clínico e sorológico semestral ao longo de um seguimento médio de 23 anos. 29 pacientes receberam tratamento tripanossomicida e 37 outras permaneceram sem tratamento. O teste ELISA-F29 usou um antígeno recombinante obtido por expressão do gene de uma proteína flagelar de Trypanosoma cruzi de ligação de cálcio em Escherichia coli. Entre os pacientes não tratados, 36 mantiveram os títulos da CS. Um paciente apresentou sorologia duvidosa em alguns controles. ELISA-F29 apresentou reatividade constante em 35/37 e foi negativo no paciente com CS flutuante. Os pacientes tratados foram agrupados de acordo com os títulos da CS, em três grupos: 13 tornaram-se negativos, 12 diminuíram e quatro permaneceram inalterados. ELISA-F29 foi negativo nos dois primeiros grupos. O tempo de negativização foi significativamente menor para o teste ELISA-F29 do que para CS (14,5 ± 5,7 e 22 ± 4,9 anos, respectivamente). A soroconversão negativa foi observada somente nos pacientes tratados. Os resultados obtidos confirmam que o teste ELISA-F29 é útil como um indicador precoce de soronegativação em pacientes crônicos tratados.

Nifurtimox therapy for Chagas disease does not cause hypersensitivity reactions in patients with such previous adverse reactions during benznidazole treatment.

Currently, only two drugs are approved for treating Trypanosoma cruzi infection: benznidazole and nifurtimox. Adverse reactions are frequent with both drugs: they have chemical similarities and common metabolic pathways making cross reactions a possibility. Our objective was to describe the safety/tolerability profile of nifurtimox in patients who had previously discontinued benznidazole due to hypersensitivity reactions. We performed a prospective observational study from September 2009 to December 2011. Patients who discontinued benznidazole therapy due to hypersensitivity reactions (HR) and were later treated with nifurtimox were included. HR to benznidazole were defined as presence of a rash with or without mucosal involvement, fever or laboratory abnormalities (such as eosinophilia, leucopaenia or impaired liver function tests). The drugs were prescribed for 60 days (benznidazole) or 60-90 days (nifurtimox). The National Cancer Institute criteria (CTCAE, 2006, Version 3.0) were used for grading and reporting of adverse reactions (AR). Eighteen patients (16 females, two males, median age 35.5 years, range 15-50 years) with asymptomatic late chronic infection, were included. Median time between benznidazole interruption and start of therapy with nifurtimox was 121.5 days (IQR 72-223 days). Fifteen patients (83.3%) developed an AR to nifurtimox, gastrointestinal complaints and anorexia being the most common, and 13 patients (72%) completed the treatment schedule. Five patients interrupted therapy (27.8%) mainly because of gastrointestinal intolerance and/or nervous system toxicity. Only one patient developed skin lesions, a mild maculopapular rash not requiring specific therapy or treatment withdrawal. There was no severe AR. Nifurtimox as second line therapy in patients who discontinued benznidazole specifically due to HR appears to be safe and does not seem to be associated with a higher incidence of AR.

Immunosuppression and Chagas disease: a management challenge.

Immunosuppression, which has become an increasingly relevant clinical condition in the last 50 years, modifies the natural history of Trypanosoma cruzi infection in most patients with Chagas disease. The main goal in this setting is to prevent the consequences of reactivation of T. cruzi infection by close monitoring. We analyze the relationship between Chagas disease and three immunosuppressant conditions, including a description of clinical cases seen at our center, a brief review of the literature, and recommendations for the management of these patients based on our experience and on the data in the literature. T. cruzi infection is considered an opportunistic parasitic infection indicative of AIDS, and clinical manifestations of reactivation are more severe than in acute Chagas disease. Parasitemia is the most important defining feature of reactivation. Treatment with benznidazole and/or nifurtimox is strongly recommended in such cases. It seems reasonable to administer trypanocidal treatment only to asymptomatic immunosuppressed patients with detectable parasitemia, and/or patients with clinically defined reactivation. Specific treatment for Chagas disease does not appear to be related to a higher incidence of neoplasms, and a direct role of T. cruzi in the etiology of neoplastic disease has not been confirmed. Systemic immunosuppressive diseases or immunosuppressants can modify the natural course of T. cruzi infection. Immunosuppressive doses of corticosteroids have not been associated with higher rates of reactivation of Chagas disease. Despite a lack of evidence-based data, treatment with benznidazole or nifurtimox should be initiated before immunosuppression where possible to reduce the risk of reactivation. Timely antiparasitic treatment with benznidazole and nifurtimox (or with posaconazole in cases of therapeutic failure) has proven to be highly effective in preventing Chagas disease reactivation, even if such treatment has not been formally incorporated into management protocols for immunosuppressed patients. International consensus guidelines based on expert opinion would greatly contribute to standardizing the management of immunosuppressed patients with Chagas disease.

Profilaxis de enfermedad de Chagas en niños y adultos sometidos a trasplante de órganos sólidos y de precursores hematopoyéticos / Prophylaxis against Chagas disease in pediatric and adult patients undergoing solid organ and hematopoietic stem cells transplantation

Chagas disease is a zoonosis caused by T. cruzi. The estimated prevalence in endemic areas is 0.6-0.9 / 100,000. In immunocompromised behaves as an opportunistic pathogen highly aggressive and can evolve with meningoencephalitis, myocarditis or systemic disease. We recommend obtaining serology for all donor and recipient of SOT and HSCT. An infected donor should be discarded as such. In the case of D (-) R (+) exists controversy between prophylaxis and pre emptive therapy. The chosen drug for prophylaxis is nifurtimox for 3 months, effective but with relevant adverse effects. Monitoring should be done with RPC and MicroStrout weekly until six months post-transplant, then on a monthly basis for the duration of immunosuppression and continued for life clinical monitoring (C3).

La enfermedad de Chagas es una zoonosis producida por T. cruzi. La prevalencia estimada en áreas endémicas es de 0,6-0,9/100.000 habitantes . En inmunocomprome-tidos se comporta como un patógeno oportunista de alta agresividad, pudiendo evolucionar con cuadros meningo-encefálicos, miocárdicos o sistémicos. Se recomienda obtener serología para todo donante y receptor de TOS y TPH. Un donante infectado se descarta como tal. En caso de D (-) R (+) existe controversia entre realizar proilaxis o vigilancia más terapia anticipada. La proilaxis aceptada es con nifurtimox por tres meses, efectiva pero con efectos adversos importantes. El seguimiento debe realizarse con RPC y MicroStrout semanal hasta los seis meses post-trasplante; luego, en forma mensual mientras dure la inmunosupresión y continuar de por vida la vigilancia clínica (C3).

Reactivation of Chagas' disease: cutaneous manifestations in two immunosuppressed patients.

BACKGROUND: Chagas' disease is a zoonosis caused by a protozoan agent, Trypanosoma cruzi. Patients undergoing immunosuppressive treatment due to organ transplant, malignancies, infections, or chemotherapy may reactivate a preexisting chronic or indeterminate Trypanosoma cruzi infection. METHODS: We present two transplant patients who underwent reactivation of Chagas' disease with cutaneous manifestations after an augmentation in their immunosuppressive therapy. A 38-year-old man was hospitalized on day 69 after receiving an allogeneic bone marrow transplant; he developed multiple painful erythematous plaques with diffuse borders, confined to the right cheek, trunk, thigh, elbows, and feet. A 59-year-old woman with a 14-year history of Chagasic cardiomyopathy presented one month after heart transplantation with a painful infiltrated purpuric plaque on the back of her right leg. RESULTS: In both cases, histologic examination of skin biopsies showed dermal infiltration with intrahistiocytic amastigotes. In one of the reported cases, the Strout method detected parasitemia. Treatments with nifurtimox (600 mg/d) in case 1 and benznidazole (400 mg/d) in case 2 were started. Fever and cutaneous lesions resolved immediately after seven days of treatment. CONCLUSIONS: Reactivation of Chagas' disease is a serious complication that usually occurs in immunocompromised patients. Clinical manifestations include febrile illness occasionally associated with painful skin lesions. Early diagnosis and proper treatment can significantly improve these patients' outcome.