Transplantation for Chagas’ disease: an overview of immunosuppression and reactivation in the last two decades

Survival of Heart Transplant Patients with Chagas' Disease Under Different Antiproliferative Immunosuppressive Regimens

Chagas' disease (CD) is an important cause of heart transplantation (HT). The main obstacle is Chagas' disease reactivation (CDR), usually associated to high doses of immunosuppressants. Previous studies have suggested an association of mycophenolate mofetil with increased CDR. However, mortality predictors are unknown. To identify mortality risk factors in heart transplant patients with CD and the impact of antiproliferative regimen on survival. Retrospective study with CD patients who underwent HT between January 2004 and September 2020, under immunosuppression protocol that prioritized azathioprine and change to mycophenolate mofetil in case of rejection. We performed univariate regression to identify mortality predictors; and compared survival, rejection and evidence of CDR between who received azathioprine, mycophenolate mofetil and those who changed from azathioprine to mycophenolate mofetil after discharge ("Change" group). A p-value < 0.05 was considered statistically significant. Eighty-five patients were included, 54.1% men, median age 49 (39-57) years, and 91.8% were given priority in waiting list. Nineteen (22.4%) used azathioprine, 37 (43.5%) mycophenolate mofetil and 29 (34.1%) switched therapy; survival was not different between groups, 2.9 (1.6-5.0) x 2.9 (1.8-4.8) x 4.2 (2.0-5.0) years, respectively; p=0.4. There was no difference in rejection (42%, 73% and 59% respectively; p=0.08) or in CDR (T. cruzi positive by endomyocardial biopsy 5% x 11% x 7%; p=0.7; benznidazole use 58% x 65% x 69%; p=0.8; positive PCR for T. cruzi 20% x 68% x 42% respectively; p=0.1) rates. This retrospective study did not show difference in survival in heart transplant patients with CD receiving different antiproliferative regimens. Mycophenolate mofetil was not associated with statistically higher rates of CDR or graft rejection in this cohort. New randomized clinical trials are necessary to address this issue.

WHF Recommendations for the Use of Echocardiography in Chagas Disease

Chagas disease (ChD) represents a significant health burden in endemic regions of Latin America and is increasingly being recognized as a global health issue. The cardiac involvement in ChD, known as Chagas cardiomyopathy (ChCM), is the most severe manifestation and a leading cause of heart failure and mortality in affected individuals. Echocardiography, a non-invasive imaging modality, plays a crucial role in the diagnosis, monitoring, and risk stratification of ChCM. This consensus recommendation aims to provide guidance on the appropriate use of echocardiography in ChD. An international panel of experts, including cardiologists, infectious disease specialists, and echocardiography specialists, convened to review the available evidence and provide practical recommendations based on their collective expertise. The consensus addresses key aspects related to echocardiography in ChD, including its role in the initial evaluation, serial monitoring, and risk assessment of patients. It emphasizes the importance of standardized echocardiographic protocols, including the assessment of left ventricular function, chamber dimensions, wall motion abnormalities, valvular involvement, and the presence of ventricular aneurysm. Additionally, the consensus discusses the utility of advanced echocardiographic techniques, such as strain imaging and 3D echocardiography, in assessing myocardial mechanics and ventricular remodeling.

Transplantation for chagas' disease: closing the knowledge gap

PURPOSE OF THE REVIEW

This review examines the most recent literature on the epidemiology and treatment of Chagas Disease and the risk of Chagas Disease Reactivation and donor-derived disease in solid organ transplant recipients.

RECENT FINDINGS

Chagas disease is caused by infection with the parasite Trypansoma cruzi . In nonendemic countries the disease is seen primarily in immigrants from Mexico, Central America and South America where the disease is endemic. Benznidazole or nifurtimox can be used for treatment. Posaconazole and fosravuconazole did not provide any additional benefit compared to benznidazole alone or in combination. A phase 2 randomized controlled trial suggests that shorter or reduced dosed regimes of benznidazole could be used. Based on a large randomized controlled trial, benznidazole is unlikely to have a significant preventive effect for established Chagas cardiomyopathy. Transplantation has become the treatment of choice for individuals with refractory Chagas cardiomyopathy. Cohort studies show similar posttransplant outcomes for these patients compared to other indications. Transplant candidates and donors with chronic T. cruzi infection are at risk for Chagas disease reactivation and transmitting infection. Screening them via serology is the first line of prevention. Recipients with chronic infection and those receiving organs from infected donors should undergo sequential monitoring with polymerase chain reaction for early detection of reactivation and preemptive treatment with antitrypanosomal therapy.

SUMMARY

Patients with chronic T. cruzi infection can be safely transplanted and be noncardiac organ donors.

Different profiles and epidemiological scenarios: past, present and future

The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.

Unexpected Case of Chagas Disease Reactivation in Endomyocardial Biopsy for Evaluation of Cardiac Allograft Rejection

Acute Chagas disease reactivation (CDR) after cardiac transplantation is a well-known phenomenon in endemic countries of Central and South America and Mexico, but is rare outside of those countries. In this report, we describe a case of a 49 year old male who presented 25 weeks after heart transplant with clinical features concerning for acute rejection, including malaise, anorexia, weight loss, and fever. His immunosuppression therapy included tacrolimus, mycophenolate, and prednisone. An endomyocardial biopsy revealed lymphocytic and eosinophilic inflammation, myocyte damage, and rare foci of intracellular organisms consistent with Trypanosoma cruzi amastigotes. The patient had no known history of Chagas disease. Upon additional questioning, the patient endorsed bites from reduviid bugs during childhood in El Salvador. Follow-up serum PCR testing was positive for T. cruzi DNA. Tests for other infectious organisms and donor specific antibodies were negative. This case illustrates the striking clinical and histologic similarities between acute cellular rejection and acute CDR with cardiac involvement in heart transplant patients, and thus emphasizes the importance of pre-transplant testing for Chagas in patients with epidemiologic risk factors.

Parasitic Load Correlates With Left Ventricular Dysfunction in Patients With Chronic Chagas Cardiomyopathy

Background: Chronic Chagas disease (CChD), one of the infectious parasitic diseases with the greatest social and economic impact upon a large part of the American continent, has distinct clinical manifestations in humans (cardiac, digestive, or mixed clinical forms). The mechanisms underlying the development of the most common and ominous clinical form, the chronic Chagas cardiomyopathy (CCC) have not been completely elucidated, despite the fact that a high intensity of parasite persistence in the myocardium is deemed responsible for an untoward evolution of the disease. The present study aimed to assess the parasite load CCC and its relation to left ventricular ejection fraction (LVEF), a definite prognostic marker in patients with CCC.

Methods: Patients with CCC were clinically evaluated using 12-lead-electrocardiogram, echocardiogram, chest X-ray. Peripheral blood sampling (5 ml of venous blood in guanidine/EDTA) was collected from each patient for subsequent DNA extraction and the quantification of the parasite load using real-time PCR.

Results: One-hundred and eighty-one patients with CCC were evaluated. A total of 140 (77.3%) had preserved left ventricular ejection fraction (of ≥40%), and 41 individuals had LV dysfunction (LVEF of <40%). A wide variation in parasite load was observed with a, mean of 1.3460 ± 2.0593 (0.01 to 12.3830) par. Eq./mL. The mean ± SD of the parasite load was 0.6768 ± 0.9874 par. Eq./mL and 3.6312 ± 2.9414 par. Eq./mL in the patients with LVEF ≥ 40% and <40%, respectively.

Conclusion: The blood parasite load is highly variable and seems to be directly related to the reduction of LVEF, an important prognostic factor in CCC patients.

Sixteen Years of Heart Transplant in an Open Cohort in Brazil: Analysis of Graft Survival of Patients using Immunosuppressants

BACKGROUND

Heart transplant is the main therapeutic alternative for advanced heart failure patients. Several risk factors affect these patients' survival; however, few studies about the topic are available in Brazil.

OBJECTIVES

To review the survival rates of heart transplant patients in the Brazilian Public Health System (Sistema Único de Saúde - SUS) between 2000 and 2015.

METHODS

This is a non-concurrent, open cohort study, involving cardiac transplant patients in Brazil. The cumulative survival probability was estimated by the Kaplan-Meier curve, and the curve comparison was done using the Log-Rank test. The Cox model was used to calculate the Hazard-Ratio (HR). Analyses were conducted at the 95% confidence level.

RESULTS

The heart transplant survival rate median in Brazil, during the period, was 8.3 years. Each additional year in the recipient's age, the occurrence of infections, and the performance of the surgical procedure in the South Region were associated with a higher risk of graft loss. A higher use ratio of immunosuppressants mycophenolate and azathioprine acted as a protection factor.

CONCLUSIONS

The analyses conducted provide the first information about the median survival time in heart transplant patients in Brazil. The difference noticed among the geographical regions may be related to the different treatment protocols adopted in the country, especially in the early 2000s. The rate of mycophenolate and azathioprine use as a protection factor suggests that, despite the absence of differences among therapeutic strategies, use of these drugs may favor survival of certain patients. The study provides robust epidemiological data, which are relevant for public health.

Lobular panniculitis of the thigh as the only cutaneous manifestation of reactivation of Chagas disease in a renal transplant patient: a case report

Reactivation of chronic Trypanosoma cruzi infection in solid organ transplant recipients (SOTRs) has been reported. The patient presented with a 2-week history of two painful erythematous, infiltrated plaques with central ulceration and necrotic crust on the left thigh. She had a history of chronic indeterminate Chagas disease (CD) and had received a kidney transplant before 2 months. Skin biopsies revealed lobular panniculitis with intracellular amastigote forms of T. cruzi. The patient was diagnosed with CD reactivation. Treatment with benznidazole significantly improved her condition. CD reactivation should be suspected in SOTRs living in endemic areas with clinical polymorphism of skin lesions.

Usefulness of PCR for Trypanosoma cruzi DNA in blood and endomyocardial biopsies for detection of Chagas disease reactivation after heart transplantation: A comparative study

BACKGROUND

Chagas disease reactivation (CDR) after heart transplantation is characterized by relapse of the infectious disease with proliferation and dissemination of Trypanosoma cruzi parasites. Serial blood PCR testing is consensually recommended for CDR monitoring, but there is uncertainty about the incremental value in performing the molecular tests in endomyocardial biopsies (EMB).

METHODS

We compared qualitative and quantitative results of PCR for T cruzi DNA in 62 pairs of blood and EMB collected with a maximum time interval of 7 days, from 34 heart-transplanted, chagasic patients.

RESULTS

Blood PCR resulted positive in 39/62 (62.9%) samples, with PL ranging from 0.14 to 1610.73 (median: 3.31). PCR resulted positive in 8/60 (13.3%) EMB, with PL ranging from 2.82 to 1670.55 (median: 65.63). All blood samples which tested negative presented a paired EMB which also tested negative. However, 31/39 (79.5%) blood samples which tested positive presented a paired EMB which tested negative. There was poor agreement between blood and EMB PCR (kappa = 0.153). CDR affecting the myocardium (myo-CDR) was diagnosed in three occasions. PCR resulted positive in both blood and EMB at the time of myo-CDR, with PL ranging from 0.61 to 1610.73 in blood and 13.8 to 1670.55 in EMB.

CONCLUSIONS

Negative PCR for T cruzi in blood rules out myo-CDR, with no value of testing EMB. Positive PCR in blood with high PL is diagnostic for myo-CDR. If PCR in blood results positive with low PL, testing EMB is useful: negative PCR turns unlikely, and positive PCR reinforces greatly the possibility of myo-CDR.

Survival after heart transplantation for Chagas cardiomyopathy using a conventional protocol: A 10-year experience in a single center

BACKGROUND

Heart transplant (HT) remains the most frequently indicated therapy for patients with end-stage heart failure that improves prognosis in Chagas cardiomyopathy (CCM). However, the lack of benznidazole therapy and availability of RT-PCR follow-up in many centers is a major limitation to perform this life-saving intervention, as there are concerns related with the risk of reactivation. We aimed to describe the outcomes of a cohort of patients with CCM who underwent HT using a conventional protocol with mycophenolate mofetil, without benznidazole prophylaxis or RT-PCR follow-up.

METHODS

Retrospective cohort study. Between 2008 and 2018, 43 patients with CCM underwent HT. A descriptive analysis to characterize outcomes as rejection, infectious and neoplastic complications and a survival analysis was carried out.

RESULTS

Median of follow-up was 4.3 (IR 4.28) years. Survival at 1 month, 1 year, and 5 years was 95%, 85%, and 75%, respectively, infections being the main cause of death (60%). Reactivations occurred in only three patients (7.34%) and were not related to mortality.

CONCLUSION

This cohort showed a favorable survival and a low reactivation rate without an impact on mortality. Our results suggest that performing HT in patients with CCM following conventional guidelines and recommendations for other etiologies is a safe approach.

Circulating Trypanosoma cruzi load and major cardiovascular outcomes in patients with chronic Chagas cardiomyopathy: a prospective cohort study

OBJECTIVES

To analyse the effect of parasite load assessed by quantitative reverse transcription PCR (RT-qPCR) in serum on the prognosis of patients with chronic Chagas cardiomyopathy (CCM) after a 2-year follow-up.

METHODS

Prospective cohort study conducted between 2015 and 2017. One hundred patients with CCM were included. Basal parasitaemia levels of Trypanosoma cruzi (T. cruzi) were measured using a quantitative polymerase chain reaction (qPCR) test. The primary composite outcome (CO) was all-cause mortality, cardiac transplantation and implantation of a left ventricular assist device. Secondary outcomes were the baseline levels of serum biomarkers and echocardiographic variables.

RESULTS

After a 2 years of follow-up, the primary CO rate was 16%. A positive qPCR was not associated with a higher risk of the CO. However, when parasitaemia was evaluated by comparing tertiles (tertile 1: undetectable parasitaemia, tertile 2: low parasitaemia and tertile 3: high parasitaemia), a higher risk of the CO (HR 3.66; 95% CI 1.11-12.21) was evidenced in tertile 2. Moreover, patients in tertile 2 had significantly higher levels of high-sensitivity troponin T and cystatin C and more frequently exhibited an ejection fraction <50%.

CONCLUSION

Low parasitaemia was associated with severity markers of myocardial injury and a higher risk of the composite outcome when compared with undetectable parasitaemia. This finding could be hypothetically explained by a more vigorous immune response in patients with low parasitaemia that could decrease T. cruzi load more efficiently, but be associated with increased myocardial damage. Additional studies with a larger number of patients and cytokine measurement are required to support this hypothesis.

Benznidazole as Prophylaxis for Chagas Disease Infection Reactivation in Heart Transplant Patients: A Case Series in Brazil

Background—Patients with Chagas cardiomyopathy (CC) have high mortality, and CC is a common indication for heart transplantation (HTx) in endemic countries. Chagas disease reactivation (CDR) is common after transplantation and is likely to cause adverse outcomes unless detected and treated appropriately. This study reviews our experiences with HTx among patients with CC, and the use of benznidazole (BZ) before transplantation. Methods—During the 18-year period from 1996 through 2014, 70 of 353 patients who underwent HTx (19.8%) had CC, and 53 patients met the inclusion criteria. The effectiveness of prophylactic treatment with BZ (dose of 5 mg/kg/day, two times per day, for at least four weeks and for a maximum of eight weeks) was determined based on the observed reduction in the incidence of CDR during the post-HTx period. Results—Prophylactic therapy was administered to 18/53 patients (34.0%). During the follow-up period, the incidence rate of CDR in our study was 34.0% (18/53). Based on logistic regression analysis, only prophylaxis (OR = 0.12; CI 0.02–0.76; p = 0.025) was considered to protect against CDR. Conclusion—Our study suggests that the use of BZ may reduce the incidence of CDR in patients undergoing HTx and warrants further investigation in a prospective, randomized trial.

Chagas Disease Infection Reactivation after Heart Transplant

Chagas disease, caused by a Trypanosona cruzi infection, is one of the main causes of heart failure in Latin America. It was originally a health problem endemic to South America, predominantly affecting residents of poor rural areas. With globalization and increasing migratory flows from these areas to large cities, the immigration of T. cruzi chronically-infected people to developed, non-endemic countries has occurred. This issue has emerged as an important consideration for heart transplant professionals. Currently, Chagas patients with end-stage heart failure may need a heart transplantation (HTx). This implies that in post-transplant immunosuppression therapy to avoid rejection in the recipient, there is the possibility of T. cruzi infection reactivation, increasing the morbidity and mortality rates. The management of heart transplant recipients due to Chagas disease requires awareness for early recognition and parasitic treatment of T. cruzi infection reactivation. This issue poses challenges for heart transplant professionals, especially regarding the differential diagnosis between rejection and reactivation episodes. The aim of this review is to discuss the complexity of the Chagas disease reactivation phenomenon in patients submitted to HTx for end-stage chagasic cardiomyopathy.

Chagas Disease: Chronic Chagas Cardiomyopathy

Chagas disease (CD) is a tropical vector-borne infection caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), also known as American Trypanosomiasis. It is considered endemic in all South and Central America and in this past decades its becoming a burden particularly in the United States and Europe due to human migration. The vast majority of patients during the acute phase are asymptomatic, while chronic symptomatic phase appears years later, with around 30% progressing toward detectable organ damage affecting mainly the cardiovascular and digestive systems. Chagas cardiomyopathy is the leading cause of nonischemic cardiomyopathy (NICM) in Latin America and affects around 30% of infected patients. The foremost characteristics are a diffuse myocarditis with focal fibrosis, mainly located in the apex and basal segments of the posterior and inferior wall, leading to a highly arrhythmogenic disease. Treatment can be etiologic during the parasitic infection, without and established efficacy during the advanced chronic symptomatic phase. Chronic Chagas cardiomyopathy treatment consists in guided medical therapy for non-ischemic cardiomyopathy, but more studies are imperative to improve clinical outcomes, some of them already in progress, and hopefully soon refine treatment and recommendations.

Chagas Disease and Heart Failure: An Expanding Issue Worldwide

Chagas disease, originally a South American endemic health problem, is expanding worldwide because of people migration. Its main impact is on the cardiovascular system, producing myocardial damage that frequently results in heart failure. Pathogenic pathways are mainly related to inmunoinflamatory reactions in the myocardium and, less frequently, in the gastrointestinal tract. The heart usually shows fibrosis, producing dilatation and damage of the electrogenic cardiac system. These changes result in cardiomyopathy with heart failure and frequent cardiac arrhythmias and heart blocks. Diagnosis of the disease must include a lab test to detect the parasite or its immune reactions and the usual techniques to evaluate cardiac function. Therapeutic management of Chagas heart failure does not differ significantly from the most common treatment for dilated cardiomyopathy, with special focus on arrhythmias and several degrees of heart block. Heart transplantation is reserved for end-stage cases. Major international scientific organisations are delivering recommendations for prevention and early diagnosis. This article provides an analysis of epidemiology, prevention, treatment and the relationship between Chagas disease and heart failure.

Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of tissue and blood protozoal infections in the pre- and post-transplant period. Significant new developments in the field have made it necessary to divide the previous single guideline published in 2013 into two sections, with the intestinal parasites separated from this guideline devoted to tissue and blood protozoa. The current update reflects the increased focus on donor screening and risk-based recipient monitoring for parasitic infections. Increased donor testing has led to new recommendations for recipient management of Toxoplasma gondii and Trypanosoma cruzi. Molecular diagnostics have impacted the field, with access to rapid diagnostic testing for malaria and polymerase chain reaction testing for Leishmania. Changes in Babesia treatment regimens in the immunocompromised host are outlined. The risk of donor transmission of free-living amebae infection is reviewed. Changing immigration patterns and the expansion of transplant medicine in developing countries has contributed to the recognition of parasitic infections as an important threat to transplant outcomes. Medications such as benznidazole and miltefosine are now available to US prescribers as access to treatment of tissue and blood protozoa is increasingly prioritized.

Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association

Background:

Chagas disease, resulting from the protozoan Trypanosoma cruzi , is an important cause of heart failure, stroke, arrhythmia, and sudden death. Traditionally regarded as a tropical disease found only in Central America and South America, Chagas disease now affects at least 300 000 residents of the United States and is growing in prevalence in other traditionally nonendemic areas. Healthcare providers and health systems outside of Latin America need to be equipped to recognize, diagnose, and treat Chagas disease and to prevent further disease transmission.

Methods and Results:

The American Heart Association and the Inter-American Society of Cardiology commissioned this statement to increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments. In this document, we summarize the most updated information on diagnosis, screening, and treatment of T cruzi infection, focusing primarily on its cardiovascular aspects. This document also provides quick reference tables, highlighting salient considerations for a patient with suspected or confirmed Chagas disease.

Conclusions:

This statement provides a broad summary of current knowledge and practice in the diagnosis and management of Chagas cardiomyopathy. It is our intent that this document will serve to increase the recognition of Chagas cardiomyopathy in low-prevalence areas and to improve care for patients with Chagas heart disease around the world.

An unusual case of congestive heart failure in the Netherlands

Introduction

Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. It is endemic to the American continent due to the distribution of its insect vectors. The disease is occasionally imported to other continents by travel of infected individuals. It is rarely diagnosed in the Netherlands and exact numbers of infected individuals are unknown. Clinical manifestations can start with an acute phase of 4-8 weeks with non-specific, mild symptoms and febrile illness. In the chronic phase, it can lead to fatal cardiac and gastro-intestinal complications.

Case presentation

We describe a case of a 40-year-old man with end-stage cardiomyopathy due to Chagas disease. He lived in Surinam for more than 20 years and had an unremarkable medical history until he was hospitalized due to pneumonia and congestive heart failure. Despite antibiotic treatment and optimizing cardiac medication, his disease progressed to end-stage heart failure for which cardiac transplantation was the only remaining treatment. A left ventricular assist device (LVAD) was implanted as a bridge to transplantation. Tissue analysis after LVAD surgery revealed ongoing myocarditis caused by Chagas disease. Based on a literature review, a scheme for follow up and treatment after transplantation was postulated.

Conclusion

Chagas disease should be taken into account in patients from endemic countries who have corresponding clinical signs. Heart transplantation in patients with Chagas cardiomyopathy is accompanied by specific challenges due to the required immunosuppressive therapy and the thereby increased risk of reactivation of a latent T. cruzi infection.

Heart transplantation for Chagas cardiomyopathy

Chagas disease is an endemic disease in Latin America that is increasingly found in non-endemic areas all over the world due to the flow of migrants from Central and South America. We present the case of a Brazilian immigrant in Portugal who underwent orthotopic heart transplantation for end-stage Chagas cardiomyopathy. Immunosuppressive therapy included prednisone, mycophenolate mofetil and tacrolimus. Twelve months after the procedure she is asymptomatic, with good graft function, and with no evidence of complications such as graft rejection, opportunistic infections, neoplasms or reactivation of Trypanosoma cruzi infection. By reporting the first case in Portugal of heart transplantation for Chagas cardiomyopathy, we aim to increase awareness of Chagas disease as an emerging global problem and of Chagas cardiomyopathy as a serious complication for which heart transplantation is a valuable therapeutic option.

Early polymerase chain reaction detection of Chagas disease reactivation in heart transplant patients

BACKGROUND

Heart transplantation is a valuable therapeutic option for Chagas disease patients with severe cardiomyopathy. During patient follow-up, the differential diagnosis between cardiac transplant rejection and Chagas disease infection reactivation remains a challenging task, which hinders rapid implementation of the appropriate treatment. Herein we investigate whether polymerase chain reaction (PCR) strategies could facilitate early detection of Trypanosoma cruzi (T cruzi) in transplanted endomyocardial biopsies (EMBs).

METHODS

In this study we analyzed 500 EMB specimens obtained from 58 chagasic cardiac transplant patients, using PCR approaches targeted to nuclear (rDNA 24Sα) and kinetoplastid (kDNA) markers, and compared the efficiency of these approaches with that of other tests routinely used.

RESULTS

T cruzi DNA was detected in 112 EMB specimens derived from 39 patients (67.2%). The first positive result occurred at a median 1.0 month post-transplant. Conventional histopathologic, blood smear and hemoculture analyses showed lower sensitivity and higher median time to the first positive result. Patient follow-up revealed that 31 of 39 PCR-positive cases presented clinical reactivation of Chagas disease at different time-points after transplantation. PCR techniques showed considerable sensitivity (0.82) and specificity (0.60), with area under the receiver operating characteristic (ROC) curves of 0.708 (p = 0.001). Moreover, PCR techniques anticipated the clinical signs of Chagas disease reactivation by up to 36 months, with a median time of 6 months and an average of 9.1 months.

CONCLUSIONS

We found a good association between the PCR diagnosis and the clinical signs of the disease, indicating that the PCR approaches used herein are suitable for early diagnosis of Chagas disease reactivation, with high potential to assist physicians in treatment decisions. For this purpose, an algorithm is proposed for surveillance based on the molecular tests.

Heart transplant recipient with history of Chagas disease and elevated panel-reactive antibodies

Chagas disease is caused by a protozoan named Trypanosoma cruzi transmitted to humans by reduviid bugs. Severe dilated cardiomyopathy from chronic T cruzi infection is the most common finding, leading to end-stage heart failure. Heart transplant is an effective treatment for Chagas heart disease. However, T cruzi reactivation is of great concern, predisposing patients to episodes of myocarditis and rejection. A 56-year-old woman with a history of Chagas disease and elevated calculated panel reactive antibodies (CPRAs) underwent induction therapy and desensitization strategies aimed at lowering CPRAs, as elevated CPRAs have been implicated in the development of antibody-mediated rejection and reduced allograft survival. Clinical phases and signs and symptoms of Chagas disease are briefly described in an attempt to promote awareness of the disease among clinicians. In addition, serology assays approved in the United States as well as recommendations of experts on Chagas disease to assess tissues and blood specimens from endemic areas are outlined. Ultimately, the importance of ongoing surveillance is emphasized, as the future of heart transplant recipients with Chagas disease is unpredictable and the presence or reactivation of the disease requires prompt attention in an effort to prevent graft failure and death.

Sustained Domestic Vector Exposure Is Associated With Increased Chagas Cardiomyopathy Risk but Decreased Parasitemia and Congenital Transmission Risk Among Young Women in Bolivia

BACKGROUND

We studied women and their infants to evaluate risk factors for congenital transmission and cardiomyopathy in Trypanosoma cruzi-infected women.

METHODS

Women provided data and blood for serology and quantitative polymerase chain reaction (PCR). Infants of infected women had blood tested at 0 and 1 month by microscopy, PCR and immunoblot, and serology at 6 and 9 months. Women underwent electrocardiography (ECG).

RESULTS

Of 1696 women, 456 (26.9%) were infected; 31 (6.8%) transmitted T. cruzi to their infants. Women who transmitted had higher parasite loads than those who did not (median, 62.0 [interquartile range {IQR}, 25.8-204.8] vs 0.05 [IQR, 0-29.6]; P < .0001). Transmission was higher in twin than in singleton births (27.3% vs 6.4%; P = .04). Women who had not lived in infested houses transmitted more frequently (9.7% vs 4.6%; P = .04), were more likely to have positive results by PCR (65.5% vs 33.9%; P < .001), and had higher parasite loads than those who had lived in infested houses (median, 25.8 [IQR, 0-64.1] vs 0 [IQR, 0-12.3]; P < .001). Of 302 infected women, 28 (9.3%) had ECG abnormalities consistent with Chagas cardiomyopathy; risk was higher for older women (odds ratio [OR], 1.06 [95% confidence interval {CI}, 1.01-1.12] per year) and those with vector exposure (OR, 3.7 [95% CI, 1.4-10.2]). We observed a strong dose-response relationship between ECG abnormalities and reported years of living in an infested house.

CONCLUSIONS

We hypothesize that repeated vector-borne infection sustains antigen exposure and the consequent inflammatory response at a higher chronic level, increasing cardiac morbidity, but possibly enabling exposed women to control parasitemia in the face of pregnancy-induced Th2 polarization.

Transplantation in the tropics: lessons on prevention and management of tropical infectious diseases

Tropical infectious diseases (IDs) remain a rare complication in transplant recipients even in tropical settings, but this topic has become increasingly important during the last decade due to multiple factors. Interestingly, non-tropical countries report most of the experiences with tropical diseases. The reported experience from non-endemic regions, however, does not always reflect the experience of endemic areas. Most of the guidelines and recommendations in the literature may not be applicable in tropical settings due to logistical difficulties, cost, and lack of proven benefit. In addition, certain post-transplant prevention measures, as prophylaxis and reducing exposure risk, are not feasible. Nonetheless, risk assessment and post-transplant management of tropical IDs in tropical areas should not be neglected, and clinicians need to have a higher clinical awareness for tropical ID occurring in this population. Herein, we review the more significant tropical ID in transplant patients, focusing on relevant experience reported by tropical settings.

Adipose Tissue-Derived Mesenchymal Stromal Cells Protect Mice Infected with Trypanosoma cruzi from Cardiac Damage through Modulation of Anti-parasite Immunity

BACKGROUND

Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is a complex disease endemic in Central and South America. It has been gathering interest due to increases in non-vectorial forms of transmission, especially in developed countries. The objective of this work was to investigate if adipose tissue-derived mesenchymal stromal cells (ASC) can alter the course of the disease and attenuate pathology in a mouse model of chagasic cardiomyopathy.

METHODOLOGY/PRINCIPAL FINDINGS

ASC were injected intraperitoneally at 3 days post-infection (dpi). Tracking by bioluminescence showed that cells remained in the abdominal cavity for up to 9 days after injection and most of them migrated to the abdominal or subcutaneous fat, an early parasite reservoir. ASC injection resulted in a significant reduction in blood parasitemia, which was followed by a decrease in cardiac tissue inflammation, parasitism and fibrosis at 30 dpi. At the same time point, analyses of cytokine release in cells isolated from the heart and exposed to T. cruzi antigens indicated an anti-inflammatory response in ASC-treated animals. In parallel, splenocytes exposed to the same antigens produced a pro-inflammatory response, which is important for the control of parasite replication, in placebo and ASC-treated groups. However, splenocytes from the ASC group released higher levels of IL-10. At 60 dpi, magnetic resonance imaging revealed that right ventricular (RV) dilation was prevented in ASC-treated mice.

CONCLUSIONS/SIGNIFICANCE

In conclusion, the injection of ASC early after T. cruzi infection prevents RV remodeling through the modulation of immune responses. Lymphoid organ response to the parasite promoted the control of parasite burden, while the heart, a target organ of Chagas disease, was protected from damage due to an improved control of inflammation in ASC-treated mice.

Chagas disease in the immunosuppressed patient

This review addresses relevant aspects of Chagas disease in the immunocompromised host. Chagas disease--one of the world's most neglected diseases-has become a global public health concern. Novel transmission modalities, such as organ transplantation, evidence of parasite persistence in chronically infected individuals--with the potential for reactivation under immunosuppression--and the prolonged survival of immunosuppressed patients call for an appraisal of the disease in this particular setting. The management and outcome of solid organ transplantation in the infected recipient with special focus on heart transplantation is addressed. The guidelines for management and the outcome of the recipients of organs from infected donors are discussed, and comments on haematopoietic stem cell transplantation are included. Finally, Chagas disease in other situations of impairment of the immune system, such as HIV/AIDS and autoimmune diseases, are considered. Immunosuppression has become an increasingly frequent condition that might modify the natural history of Trypanosoma cruzi infection. A number of strategies are available for Chagas disease management in the immunosuppressed patient. First, according to recent recommendations from the health authorities in Argentina, most infected patients would benefit from being treated at diagnosis. This has not been validated for patients with different immunosuppressive disorders. A different strategy would involve treating only patients with documented reactivation (either parasitaemia or clinical manifestations). These different approaches are discussed. To reach a diagnosis of parasitaemia, monitoring is essential, either with conventional methods or with molecular techniques that are not yet available in all centres. Collaborative studies are needed to improve the level of evidence, which will allow for better guidelines.

An approach to the management of Trypanosoma cruzi infection (Chagas' disease) in immunocompromised patients

The epidemiology of Chagas disease has changed in the last decades due to migration movements, population ageing and the emergence of new transmission routes. In endemic countries, health facilities and access to healthcare are improving and T. cruzi infected patients are also benefiting from medical advances. The HIV epidemic has spread to both endemic and non-endemic areas for T. cruzi, organ transplant rates have increased recently, especially in Latin America, and other medical conditions affecting the immune system are increasing their global burden. The natural course of Chagas disease is mainly determined by the host's cellular immune response. These conditions may therefore overlap with T. cruzi infection and alter the disease's natural history which may present with atypical clinical forms and a higher associated morbidity and mortality in immunocompromised patients. The present review aims to contribute to the management of immunosuppressed patients with T. cruzi infection.

Modulation of biotransformation systems and ABC transporters by benznidazole in rats

The effect of antichagasic benznidazole (BZL; 100 mg/kg body weight/day, 3 consecutive days, intraperitoneally) on biotransformation systems and ABC transporters was evaluated in rats. Expression of cytochrome P-450 (CYP3A), UDP-glucuronosyltransferase (UGT1A), glutathione S-transferases (alpha glutathione S-transferase [GST-α], GST-μ, and GST-π), multidrug-resistance-associated protein 2 (Mrp2), and P glycoprotein (P-gp) in liver, small intestine, and kidney was estimated by Western blotting. Increases in hepatic CYP3A (30%) and GST-μ (40%) and in intestinal GST-α (72% in jejunum and 136% in ileum) were detected. Significant increases in Mrp2 (300%) and P-gp (500%) proteins in liver from BZL-treated rats were observed without changes in kidney. P-gp and Mrp2 were also increased by BZL in jejunum (170% and 120%, respectively). In ileum, only P-gp was increased by BZL (50%). The activities of GST, P-gp, and Mrp2 correlated well with the upregulation of proteins in liver and jejunum. Plasma decay of a test dose of BZL (5 mg/kg body weight) administered intraduodenally was faster (295%) and the area under the concentration-time curve (AUC) was lower (41%) for BZL-pretreated rats than for controls. The biliary excretion of BZL was higher (60%) in the BZL group, and urinary excretion of BZL did not show differences between groups. The amount of absorbed BZL in intestinal sacs was lower (25%) in pretreated rats than in controls. In conclusion, induction of biotransformation enzymes and/or transporters by BZL could increase the clearance and/or decrease the intestinal absorption of coadministered drugs that are substrates of these systems, including BZL itself.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

American trypanosomiasis

American trypanosomiasis is a parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. Chagas disease is endemic in Latin America, where an estimated 10-14 million people are infected, and an emerging disease in Europe and the USA. Trypanosoma cruzi is transmitted by blood-sucking bugs of the family Reduviidae. Rhodnius prolixus, Panstrongylus megistus, Triatoma infestans, and T. dimidiata are the main vectors in the sylvatic cycle. Non vector-borne transmission includes blood transfusion, congenital and oral transmission, transplantation, and accidental infections. Most cases of acute infection occur in childhood and are usually asymptomatic, although severe myocarditis and meningoencephalitis may occur. Approximately 30% of T. cruzi-infected people will develop the chronic stage of the disease. Chronic chagasic cardiomyopathy is characterized by progressive heart failure, arrhythmias, intraventricular conduction defects, sudden death, and peripheral thromboembolism. Acute exacerbation can occur in individuals with involvement of cellular immunity such as advanced AIDS (acquired immunodeficiency syndrome), and transplant-associated immunosuppression. Neurological involvement may present with encephalitis, meningoencephalitis, or a space-occupying cerebral lesion called chagoma. Chagas disease is a major cause of ischemic stroke in Latin America. Several epidemiological studies have found an association between T. cruzi infection and cardioembolic ischemic stroke. Benznidazole and nifurtimox are the two available trypanocide drugs against T. cruzi.

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.

Transplant-associated and blood transfusion-associated tropical and parasitic infections

Blood transfusion and transplantation may represent efficient mechanisms of spreading infectious agents to naive populations. In the developed countries, as a consequence of globalization, several factors such as international commerce, tourism, and immigration have acted as important features for the emergence or reemergence of infectious diseases previously referred to as tropical. This article reviews the relevant bacterial, protozoan and viral infections that are more frequently associated with blood transfusion and/or solid organ or marrow transplantation and may affect susceptible populations worldwide.