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.     

Emerging and under-recognized Chagas cardiomyopathy in non-endemic countries

Due to recent population emigration movements,an epidemic of Chagas disease is currently menacing most developed countries.The authors report the case of a 53-year-old Brazilian woman living in Europe for the last 10 years who developed heart failure symptoms,having a previous symptomatic sinus node disease with a pacemaker implant at age of 40 years.The diagnosis was based on serology and myocardial biopsy and the patient was treated with nifurtimox.The authors emphasize the need of a high level of suspicion in patients with suggestive epidemiology and the needof populational screening of specific high risk groups.New treatment options are also discussed.     

Toxic and therapeutic effects of Nifurtimox and Benznidazol on Trypanosoma cruzi ex vivo infection of human placental chorionic villi explants

Nifurtimox (Nfx) and Benznidazole (Bnz) are the only available drugs in use for the treatment of Chagas disease. These drugs are recommended but not fully validated in evidence-based medicine and reports about the differential toxicity of both drugs are controversial. Here, we evaluated the toxic and therapeutic effects of Nfx and Bnz on human placental chorionic villi explants (HPCVE) during ex vivo infection of Trypanosoma cruzi, performing histopathological, histochemical, immunohistochemical as well as immunofluorescence analysis of the tissue. Additionally, we determined the effect of both drugs on parasite load by real time PCR. Bnz prevents the parasite induced tissue damage in ex vivo infected HPCVE compared to Nfx, which is toxic per se. The presence of T. cruzi antigens and DNA in infected explants suggests that these drugs do not impair parasite invasion into the HPCVE. Additionally, our results confirm reports suggesting that Bnz is less toxic than Nfx and support the need for the development of more effective and better-tolerated drugs.     

Diagnóstico y tratamiento de la enfermedad de Chagas

Trypanosoma cruzi infection, or Chagas disease, was discovered more than 100 years ago by Carlos Chagas. Although the infection kills more than 15.000 people each year, it is still classified as a neglected tropical disease. Today, this disease affects eight million people in 21 Latin American countries and, due to immigration, is also present in non-endemic countries. In recent years, the size of the immigrant population with chronic imported forms of Chagas disease has increased in Spain. In addition, several cases of congenital transmission have been reported. Some patients have severe infection and require specialized treatment such as pacemaker implantation or even heart transplantation, representing a considerable clinical, social and economic burden, particularly in areas with a large immigrant population. Since the 1960s, the only drugs available for the etiological treatment of this infection have been benznidazole and nifurtimox. Although new, more effective and better tolerated compounds are urgently needed, treatment with these trypanocidal drugs is recommended in both the acute and chronic stages of Chagas disease. New strategies for diagnosis and infection control in chronically infected patients have recently been reported, allowing the effectiveness of treatments to be assessed.     

Mucosal leishmaniasis . Current scenario and prospects for treatment

Leishmaniasis causes significant morbidity and mortality and thus constitutes a serious public health problem. Even though it has long been endemic in developing countries, in recent years the economic globalization and the increased volume of international travel have extended its prevalence in developed countries. In addition, native populations may be exposed to the infection through blood transfusion and the use of blood products produced from infected asymptomatic individuals. Mucosal leishmaniasis (ML) is a chronic form of this infection, which attacks the mucosa. In most cases this form of leishmaniasis results from the metastatic spread of Leishmania (Viannia) braziliensis from cutaneous lesions. It is a healthcare issue because of its wide demographic distribution, its association with significant morbidity levels, and because of the pressing concern that tourists who travel to endemic areas might present the disease even years later. The treatment currently available for ML is based on drugs such as pentavalent antimony-containing compounds, amphotericin B deoxycholate and pentamidine and often guarantees a satisfactory clinical response. Nevertheless, it also frequently provokes serious side effects. This review offers a critical analysis of the drugs now available for the treatment of ML as also of the future prospects for the treatment of the disease.     

New treatment options for delta virus: Is a cure in sight?

Current treatment of chronic hepatitis D viral infection with interferons is poorly tolerated and effective only in a minority of patients. Despite delta virus causing the most severe form of chronic viral hepatitis, no other treatments are available. After many years of inactivity, there is now hope for new treatment approaches for delta virus and some are likely to enter clinical practice in the near future. Four new treatment approaches are currently being evaluated in phase 2 studies. These involve the hepatocyte entry inhibitor myrcludex B, the farnesyl transferase inhibitor lonafarnib, the nucleic acid inhibitor REP 2139 Ca and pegylated interferon lambda. Results obtained so far are promising, and phase 3 studies are expected shortly. This review summarizes the available data on the efficacy and safety of these new drugs.     

Chagas pediátrico en zona no endémica

Introduction

Immigration has introduced new diseases into Spanish society, one of which is Chagas disease. Young women of childbearing age and children infected with Trypanosoma cruzi from endemic areas are at risk of developing the disease years later, and pregnant women can transmit the infection through the placenta.

Methods

Serological screening for anti-T. cruzi antibodies was performed on all immigrant children coming from a Chagas endemic area and seen in our Pathology Unit between 2003 and 2008, as well as on newborns of T. cruzi positive infected pregnant women coming from Latin America. Two ELISA tests were used (bioelisa Chagas Biokit^® with recombinant antigens, and an ‘in house’ ELISA with crude antigen). Patients with sufficient sample were also screened by nested PCR (TCZ3/Z4).

Results

A total of 202 children, aged 1 day to 14 years old were included in the study, of whom 22 (10.8%) were diagnosed with asymptomatic infection, 5 of which were congenital as they were born in this country. All infected patients received treatment with benznidazole, with three of them currently with a serologically negative result after treatment.

Conclusion

Chagas disease is a new imported paediatric disease that can affect children from endemic countries, but can also be acquired in our country by vertical transmission. Therefore, we believe that it is essential to perform serological screening on all children and pregnant women in the prenatal care from endemic areas, and provide specific treatment for those infected patients, given the good results observed in the paediatric population.     

Emerging biologics in inflammatory bowel disease

Early biologic therapy is recommended in patients with inflammatory bowel disease and poor prognostic factors and in those refractory to conventional medications. Anti-tumor necrosis factor (anti-TNF) agents are the most commonly used biologic agents. However, some patients may not have an initial response to anti-TNF therapy, and one-third will develop loss of response over time. Anti-TNF drugs can also be associated with side effects. In addition, the use of biologics is currently limited by their cost, especially in developing countries. A number of new therapeutic targets, including novel small molecules, and cellular therapy are available or under investigation. These novel molecules include oral Janus kinase (JAK) inhibitor (tofacitinib), interleukin inhibitor (ustekinumab), oral SMAD7 antisense oligonucleotide (mongersen), and anti-integrin inhibitors (vedolizumab). Here, we review the mechanisms of action, the efficacy, and the safety data of these novel agents. Biological products that are highly similar to reference biologic products whose patents have expired—also known as "biosimilars"—can be produced at lower cost with similar efficacy, and are also available for the treatment of IBD. We review the efficacy data for such agents as well.

     

Intravitreous anti-VEGF for diabetic retinopathy: hopes and fears for a new therapeutic strategy

Vascular endothelial growth factor (VEGF) plays a key role in the development of both proliferative diabetic retinopathy (PDR) and diabetic macular oedema (DMO). In recent years, anti-VEGF agents have emerged as new approaches to the treatment of these devastating diabetic complications. Although Phase III studies in the diabetic population are needed, intravitreal anti-VEGF therapy is currently being used in clinical practice. Intravitreal injection is an effective means of delivering anti-VEGF drugs to the retina. However, this is an invasive procedure associated with potentially serious complications, such as endophthalmitis or retinal detachment, which may be significant for patients requiring serial treatment over many years. In addition, although delivered within the vitreous, anti-VEGF drugs could pass into the systemic circulation, which could potentially result in hypertension, proteinuria, increased cardiovascular events and impaired wound healing. Pegaptanib, ranibizumab and bevacizumab are the currently available anti-VEGF agents. Ranibizumab and bevacizumab block all VEGF isoforms, thus impairing both physiological and pathological neovascularisation. Pegaptanib only blocks the VEGF₁₆₅ isoform, and would therefore seem the best option for avoiding systemic adverse effects in diabetic patients, although this remains to be demonstrated in clinical trials. In this regard, head-to-head studies designed to evaluate not only the efficacy, but also the systemic adverse effects of these drugs in a high-risk population such as diabetic patients are warranted.     

New tuberculosis therapeutics: a growing pipeline

Novel chemotherapeutic drugs are needed to improve tuberculosis (TB) control, especially in the developing world. Given the magnitude of the problem and the resources available in countries that have the highest burden of disease, the present standards of care for the treatment of drug-susceptible TB, drug-resistant TB, TB/human immunodeficiency virus (HIV) coinfection, and latent TB infection are all unsatisfactory. Because no truly novel compounds for the treatment of TB have been discovered in the past 40 years, the recent enhanced activity in the research and development of new TB drugs is extremely encouraging. Seven compounds are presently in clinical development specifically for the treatment of TB. Other known antibiotic compound families are being investigated preclinically, in an attempt to identify new antimicrobial drugs with specific antituberculous activity. In addition, novel targets have been identified and are the subject of efforts to validate their potential usefulness in the treatment of TB.     

New treatment options for multidrug-resistant tuberculosis

Despite the development of effective treatments, tuberculosis (TB) remains a major health problem. TB continues to infect new victims and kills nearly 2 million people annually. The problem is much greater in resource-limited countries but is present worldwide. Inadequate public health resources, cost, the obligatory long treatment period, and adverse drug effects contribute to treatment failures and relapses. Drug-resistant Mycobacterium tuberculosis (MTB) strains arise spontaneously and are propagated by inadequate treatment. According to World Health Organization global data, 17% of MTB strains in new, previously untreated cases are resistant to at least one drug. Approximately, 3.3% of new MTB cases are resistant to both isoniazid and rifampin, also called multidrug resistant (MDR), and rates of MDR-TB are greater than 60% in previously treated patients in some countries. Approximately 5% of cases of MDR-TB are also resistant to fluoroquinolones and to injectable drugs, and are called extensively drug resistant (XDR). Recently, XDR strains have been isolated that are also resistant to all standard second-line anti-TB medications. Successful drug treatment of TB with complex resistance profiles is virtually impossible with currently available drugs. There is a desperate need for new compounds that cure strains resistant to currently available drugs and for drugs that are better tolerated and will shorten treatment regimens. In the short term, new strategies for the management of drug-resistant TB with currently available drugs are being explored. These include the use of high-dose isoniazid, substitution of rifabutin in a small proportion of rifampin-resistant cases, linezolid, fluoroquinolones, and phenothiazines. A number of novel drugs are undergoing clinical testing and will hopefully be available in the near future. These include the newer oxazolidinones, diarylquinolines, nitroimidazopyrans, ethenylenediamines, pyrroles, and benzothiazinones.     

Host Genetic Variants in the Pathogenesis of Hepatitis C

Direct-acting antiviral drugs (DAAs) are currently replacing antiviral therapy for Hepatitis C infection. Treatment related side effects are even worse and the emergence of resistant viruses must be avoided because of the direct-antiviral action. Altogether it remains a challenge to take treatment decisions in a clinical setting with cost restrictions. Genetic host factors are hereby essential to implement an individualized treatment concept. In recent years results on different genetic variants have been published with a strong association with therapy response, fibrosis and treatment-related side effects. Polymorphisms of the IL28B gene were identified as accurate predictors for therapy response and spontaneous clearance of HCV infection and are already used for diagnostic decisions. For RBV-induced side effects, such as hemolytic anemia, associations to genetic variants of inosine triphosphatase (ITPA) were described and different SLC28 transporters for RBV-uptake have been successfully analyzed. Fibrosis progression has been associated with variants of Vitamin D receptor (VDR) and ABCB11 (bile salt export pump). Cirrhotic patients especially have a high treatment risk and low therapy response, so that personalized antiviral treatment is mandatory. This review focuses on different host genetic variants in the pathogenesis of Hepatitis C at the beginning of a new area of treatment.     

Surveillance of Chagas disease among at-risk blood donors in Italy: preliminary results from Umberto I Polyclinic in Rome

Background

Chagas disease is a parasitic disease due to Trypanosoma cruzi, endemic in Central and Southern America, where the protozoon infects about 8–10 million people. In rural areas the infection is acquired mostly through reduviidae insect vectors, whereas in urban ones it is acquired mainly through the transfusion of blood products, vertical transmission and organ transplantation. The important migratory flows of the last decades have focused attention on possible T. cruzi transmission by transfusion also in non-endemic countries, and platelets have been recognised as the main origin of infection for recipients from serologically-positive Latino-American donors.

Materials and methods

In order to avoid the occurrence of transfusion-related cases, in 2010 systematic screening for anti-T. cruzi antibodies was started at the Umberto I Polyclinic in Rome, controlling blood donors born and/or coming from Latin-American countries in which the disease is endemic. The aim of this paper is to report the preliminary results achieved since the introduction of this screening.

Results

Anti-T. cruzi antibodies have been detected to date in 3.9% out of the 128 people examined. A seropositive subject also proved positive by polymerase chain reaction analysis and showed very light parasitaemia.

Discussion

The preliminary results are quite alarming. Indeed, serological findings exceed those reported in other non-endemic countries, and Italian travellers proved to be an insidious possible source of direct transmission. The need for systematic screening of at-risk blood donors also in non-endemic countries is emphasised.     

<Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis> Infections in Asthma

Chlamydia pneumoniae is an intracellular pathogen that has been suggested to play a role in the pathology of asthma. However, so far none of the studies have provided clear evidence for a causative role of C. pneumoniae infections in asthma, although there is little doubt that chronic C. pneumoniae infection does aggravate asthma and should be treated.The diagnosis of C. pneumoniae infection is still a matter of concern for it is dependent on trained skilled personnel and can vary significantly between different diagnostic laboratories. This fact is also one of the major problems encountered when comparing epidemiological studies investigating the possible role of C. pneumoniae infections and their impact on the pathogenesis of other diseases.With regard to therapy, long-term treatment with macrolides is the best available method to eradicate C. pneumoniae. Successful therapy for C. pneumoniae, however, can also be complicated by the high possibility of de novo infection as epidemiological studies have shown that the prevalence of antibodies to C. pneumoniae increases with age in all populations studied. In the northern hemisphere the prevalence of C. pneumoniae is also affected by seasonal conditions. It is too early to draw any conclusions from the equatorial belt countries. The available data on C. pneumoniae in tropical countries indicate a much faster infection rate during early adulthood with 100% serological prevalence at an age greater than 25 years. This data, if confirmed, would argue against C. pneumoniae causing asthma since the asthma prevalence in those countries does not increase in a parallel pattern.An alternative interpretation of most studies could be that the increased rate of C. pneumoniae infections in patients with asthma results from a modified susceptibility towards the microorganism, due to yet unknown changes of the host cell’s physiology. It should be kept in mind that increased prevalence of C. pneumoniae infection is not restricted to asthma.Further studies are needed to understand the role of C. pneumoniae, especially of chronic infection, in the pathogenesis of inflammatory diseases with a specific focus on the effect that the microorganism triggers in the infected host cell. Only when we understand what C. pneumoniae does to its host cell will we be able to judge its impact on the overall status of an affected patient, and this knowledge will help us to develop a successful therapy.     

Disease status and therapeutic end points in hepatitis B

Chronic hepatitis B virus (HBV) infection is the leading cause of cirrhosis and hepatocellular carcinoma. The availability of universal vaccination has made a significant impact in reducing the incidence of these complications. Several developments have been made in the treatment of chronic HBV infection. Three drugs (interferon alpha, lamivudine, and adefovir dipivoxil) are currently approved for use in HBV infection in the United States; these treatments have been shown to reduce morbidity and mortality for some individuals with chronic hepatitis B. However, these therapies are not universally successful and have limited long-term efficacy. In addition, the development of drug-resistant HBV mutants also impacts on the long-term benefit of some of these agents. Several new agents are currently undergoing study and will add to the list of available agents for the treatment of chronic HBV infection. In addition, the role of combination therapy using two or more agents has not been well defined in the management of hepatitis B.     

Intravenous immunoglobulin increases survival time in the acute phase of experimental Chagas disease

Chagas disease induced by Trypanosoma cruzi (Tc) infection is an important cause of mortality and morbidity affecting the cardiovascular system for which presently available therapies are insufficient and largely inadequate. Intravenous immunoglobulin (IVIg) is a therapeutic preparation containing normal polyspecific IgG obtained from plasma pools of several thousand healthy donors and is used in several autoimmune, inflammatory and infectious diseases. In the study of heart from mice chronically infected with Tc, we observed that IVIg restores type 1 atrioventricular block or bradycardia. In the present study, we investigated the effects of IVIg in acute Tc infection. Intravenous immunoglobulin administration after the first week of infection was associated with an increase in survival time. Taken together, results observed in the chronic and in the acute phase associate IVIg treatment with a favourable outcome in T. cruzi infection.     

抗隐孢子虫药物的研究进展

隐孢子虫(Cryptosporidium)是一种重要的机会致病性人兽共患寄生原虫,发展中国家第二大儿童致腹泻病原体,隐孢子虫病每年导致近840万伤残调整生命年。硝唑尼特是被美国FDA批准用于治疗隐孢子虫病的唯一药物,然而其对艾滋病人合并隐孢子虫感染者无效。由于临床上抗隐孢子虫药物的迫切需要,先后有超过200种化合物被用于隐孢子虫病的治疗研究,然而到目前仍没有筛选到适合的抗隐孢子虫药物。本文将近些年来国内外有关抗隐孢子虫药物的种类及作用方式的研究进展进行综述,以期对临床治疗隐孢子虫病提供帮助。     

Technology Insight: an overview of research in drug-eluting stents

Drug-eluting stents (DESs) have revolutionized interventional cardiology over the past few years to the extent that balloon angioplasty and bare stents did in the 1980s and 1990s. The first DESs became commercially available in Europe in 2002 and in the US in 2003, and it is estimated that up to 80% of patients who undergo stent implantation in the US now receive a DES. Two devices, Cypher sirolimus-eluting stents (Cordis Corporation, Miami Lakes, FL) and Taxus paclitaxel-eluting stents (Boston Scientific Corporation, Natick, MN), are currently licensed for sale in both regions. Multiple new devices using different drugs, carriers and stents are currently undergoing clinical trials to establish their efficacy and obtain approval for commercialization. While the remarkable reduction of restenosis has accounted for the success of DESs, concerns remain regarding long-term follow-up; published 3-year follow-up results are available for fewer than 200 patients overall. Reports of late stent thrombosis have emerged, particularly in relation to discontinuation of antiplatelet therapy. In patients treated with DESs, long-term administration of at least one antiplatelet agent must be continued following completion of the mandatory dual antiplatelet regimen. In this review, we summarize the findings available for DESs so far, discuss emerging safety and efficacy data, and look at the future directions for these devices.     

Challenges in the development of drugs for the treatment of tuberculosis

Tuberculosis infection is a serious human health threat and the early 21st century has seen a remarkable increase in global tuberculosis activity. The pathogen responsible for tuberculosis is Mycobacterium tuberculosis, which adopts diverse strategies in order to survive in a variety of host lesions. These survival mechanisms make the pathogen resistant to currently available drugs, a major contributing factor in the failure to control the spread of tuberculosis. Multiple drugs are available for clinical use and several potential compounds are being screened, synthesized, or evaluated in preclinical or clinical studies. Lasting and effective achievements in the development of anti-tuberculosis drugs will depend largely on the proper understanding of the complex interactions between the pathogen and its human host. Ample evidence exists to explain the characteristics of tuberculosis. In this study, we highlighted the challenges for the development of novel drugs with potent bacteriostatic or bactericidal activity, which reduce the minimum time required to cure tuberculosis infection.     

Benznidazole treatment in chronic children infected with Trypanosoma cruzi: Serological and molecular follow-up of patients and identification of Discrete Typing Units

A total of 221 children from two rural settlements in Northeast Argentina were examined for T. cruzi infection. Blood samples were taken for serology tests and PCR assays. In addition, T. cruzi Discrete Typing Units (DTUs) were determined by hybridization with specific DNA probes of the minicircle hypervariable regions (mHVR). Serological results indicated that 26% (57/215) were reactive against T. cruzi antigens. PCR analyses were performed on seropositive samples showing presence of parasite DNA in 31 out of 53 samples (58.5%). All seropositive children underwent specific chemotherapy with Benznidazole (5 mg/kg/day) for a period of two months and were monitored two and five years after treatment. Overall the treatment was well tolerated and low side effects were observed. Serological conversion was observed at two years post -treatment in one child form Pampa Ávila and at five years in two children from Tres Estacas. However, at the end of the follow-up period, T. cruzi DNA could not be detected by PCR in samples from treated children, except in two cases. In addition, the results of hybridizations with specific DNA probes showed that DTU TcV was detected in 68% (21/31), TcVI in 7% (2/31) and TcV/VI in 3% (1/31) of the samples. Altogether, results of the follow-up of treated children showed a low rate of seroconversion; however trend toward seroconversion was evident at five years post-treatment. On the other hand, detection of T. cruzi DNA by PCR significantly decreased after Benznidazole treatment. The existence of data regarding serological and molecular follow-ups from controlled studies in the Chaco Region will be important for future treatment efforts against T. cruzi infection in this region. The results obtained in the present study represent a contribution in this regard.