Infectious, malignant, and autoimmune complications in pediatric heart transplant recipients

Case Report: "Primary Immunodeficiency"-Severe Autoimmune Enteropathy in a Pediatric Heart Transplant Recipient Treated With Abatacept and Alemtuzumab

Disorders of immune dysregulation following heart transplantation in children have been reported; however, the management of such disorders remains uncertain and challenging. In this case report, we describe a clinical course of a child with severe autoimmune enteropathy after a heart transplant in infancy and detail a treatment approach with abatacept and alemtuzumab. A 21-month-old girl with a medical history of congenital dilated cardiomyopathy and heart transplantation at 2 months was evaluated for chronic hematochezia. The patient underwent an extensive workup, including endoscopic biopsy which showed crypt apoptosis, similar to that seen with graft-versus-host disease (GVHD). Results of her immune workup were consistent with status post-thymectomy but also demonstrated evidence of immune dysregulation. Specifically, her immune phenotype at diagnosis demonstrated T-cell lymphopenia, restricted TCR repertoire and skewing of T-cell compartment toward memory phenotype, increase in serum soluble ILR2a, and hypergammaglobulinemia. In the absence of response to more standard immune modulation, the patient was treated with CTLA4-Ig (abatacept), followed by a combination of abatacept and a JAK inhibitor and, finally, a combination of abatacept and alemtuzumab. Following therapy with alemtuzumab, the patient achieved remission for the first time in her life. Her clinical course was complicated by a relapse after 6 months which again readily responded to alemtuzumab. Ultimately, despite these remissions, the patient suffered an additional relapse. This case highlights the challenges of neonatal thymectomy and adds new insights into the pathogenesis, diagnosis, and management of severe autoimmune enteropathy in pediatric heart transplant recipients.

Beta-blockers for congestive heart failure in children

BACKGROUND

Beta-blockers are an essential part of standard therapy in adult congestive heart failure and therefore, are expected to be beneficial in children. However, congestive heart failure in children differs from that in adults in terms of characteristics, aetiology, and drug clearance. Therefore, paediatric needs must be specifically investigated. This is an update of a Cochrane review previously published in 2009.

OBJECTIVES

To assess the effect of beta-adrenoceptor-blockers (beta-blockers) in children with congestive heart failure.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and LILACS up to November 2015. Bibliographies of identified studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised, controlled, clinical trials investigating the effect of beta-blocker therapy on paediatric congestive heart failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and assessed data from the included trials.

MAIN RESULTS

We identified four new studies for the review update; the review now includes seven studies with 420 participants. Four small studies with 20 to 30 children each, and two larger studies of 80 children each, showed an improvement of congestive heart failure with beta-blocker therapy. A larger study with 161 participants showed no evidence of benefit over placebo in a composite measure of heart failure outcomes. The included studies showed no significant difference in mortality or heart transplantation rates between the beta-blocker and control groups. No significant adverse events were reported with beta-blockers, apart from one episode of complete heart block. A meta-analysis of left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) data showed a very small improvement with beta-blockers. However, there were vast differences in the age, age range, and health of the participants (aetiology and severity of heart failure; heterogeneity of diagnoses and co-morbidities); there was a range of treatments across studies (choice of beta-blocker, dosing, duration of treatment); and a lack of standardised methods and outcome measures. Therefore, the primary outcomes could not be pooled in meta-analyses.

AUTHORS' CONCLUSIONS

There is not enough evidence to support or discourage the use of beta-blockers in children with congestive heart failure, or to propose a paediatric dosing scheme. However, the sparse data available suggested that children with congestive heart failure might benefit from beta-blocker treatment. Further investigations in clearly defined populations with standardised methodology are required to establish guidelines for therapy. Pharmacokinetic investigations of beta-blockers in children are also required to provide effective dosing in future trials.

Comparison of tuberculin skin test and interferon gamma release assay in pediatric candidates of heart transplantation and a 2-year follow-up

BACKGROUND

Currently, tuberculin skin test (TST) and interferon gamma release assay (IGRA) are used to find the latent tuberculosis infection (LTBI) cases in the candidates of heart transplantation. Therefore, this study aimed to compare TST and IGRA to diagnose LTBI in pediatric heart transplant candidates.

METHODS

This cross-sectional study was performed on 50 children, who were candidates for heart transplantation, of whom 42 cases underwent heart transplantation in Shahid Rajaie Cardiovascular, Medical, and Research center, Tehran, Iran, from 2016 to 2017.

RESULTS

Participants of the study included 24 male patients (%48) (p-value = 0.67). The mean age of the patients was 8.18 ± 4.27 years (1-16 years). According to the results, IGRA was negative in all patients, and no indeterminate result was reported, while the purified derivative test (PPD) was positive in three (6%) cases. In comparison with QFT, an accuracy of 94% was achieved for TST to diagnose Mycobacterium tuberculosis infection.

CONCLUSIONS

It seems that TST can still be used as an accurate test for screening LTBI in pediatric candidates for heart transplantation.

Toward a solution for cardiac failure in the newborn

The newborn infant with severe cardiac failure owed to congenital structural heart disease or cardiomyopathy poses a daunting therapeutic challenge. The ideal solution for both might be cardiac transplantation if availability of hearts was not limiting and if tolerance could be induced, obviating toxicity of immunosuppressive therapy. If one could safely and effectively exploit neonatal tolerance for successful xenotransplantation of the heart, the challenge of severe cardiac failure in the newborn infant might be met. We discuss the need, the potential for applying neonatal tolerance in the setting of xenotransplantation and the possibility that other approaches to this problem might emerge.

Recurrent oral ulcerations following heart transplant in a pediatric patient: A diagnostic dilemma

Oral ulceration is a non-specific clinical finding with many potential causes. The persistence of oral ulcers in the context of a patient post-SOT is concerning for PTLD. There is growing evidence that SOT recipients may also be at higher risk of autoimmune diseases. This case report describes a pediatric patient with persistent oral ulcers after heart transplant, who underwent an extensive workup for PTLD, including repeat investigations, with a subsequent diagnosis of Behçet's disease.

Heart Transplantation in Children with Turner Syndrome: Analysis of a Linked Dataset

Turner syndrome (TS) patients with hypoplastic left heart syndrome (HLHS) have poor single ventricle palliation outcomes; therefore, consideration of other potential management strategies is important. Little is known about heart transplantation (HTx) in this group, as standard HTx databases do not allow for identification of TS. This study describes experiences and outcomes of HTx in TS using a unique linkage between the Scientific Registry of Transplant Recipients and the Pediatric Health Information System databases. All pediatric HTx recipients (2002-2016) with TS were identified in the database using ICD-9 code 758.6 (gonadal dysgenesis) in conjunction with female sex. Patient characteristics and outcomes were described. Fourteen patients with TS were identified who underwent 16 HTx procedures at eight centers. For initial HTx, HLHS was the most common indication (10/14) with a median age of 10 months (IQR 3-73 months). Median transplant-free survival following initial HTx was 4.1 years (IQR 16 days-10.5 years), with all deaths occurring in the first year post-HTx. For patients that survived past 1 year (8/14), follow-up ranged from 4.1 to 10.9 years (median 8.0 years) with no deaths observed. Our cohort demonstrates that while there is a clear risk for early mortality, there is the potential for favorable outcomes following HTx in patients with TS. Therefore, TS should not be viewed as an absolute contraindication to HTx, but careful assessment of candidate risk is needed. Primary palliation with HTx for HLHS and TS may be a reasonable consideration given the poor outcomes of single ventricle palliation in this group. Further research is needed to fully delineate the outcomes and characteristics of this unique population.

Bacterial infections after pediatric heart transplantation: Epidemiology, risk factors and outcomes

BACKGROUND

Bacterial infections represent a major cause of morbidity and mortality in heart transplant recipients. However, data describing the epidemiology and outcomes of these infections in children are limited.

METHODS

We analyzed the Pediatric Heart Transplant Study database of patients transplanted between 1993 and 2014 to determine the etiologies, risk factors and outcomes of children with bacterial infections post-heart transplantation.

RESULTS

Of 4,458 primary transplants in the database, there were 4,815 infections that required hospitalization or intravenous therapy, 2,047 (42.51%) of which were bacterial. The risk of bacterial infection was highest in the first month post-transplant, and the bloodstream was the most common site (24.82%). In the early post-transplant period (<30 days post-transplant), coagulase-negative staphylococci were the most common pathogens (16.97%), followed by Enterobacter sp (11.99%) and Pseudomonas sp (11.62%). In the late post-transplant period, community-acquired pathogens Streptococcus pneumoniae (6.27%) and Haemophilus influenzae (2.82%) were also commonly identified. Patients' characteristics independently associated with acquisition of bacterial infection included younger age (p < 0.0001) and ventilator (p < 0.0001) or extracorporeal membrane oxygenation (p = 0.03) use at time of transplant. Overall mortality post-bacterial infection was 33.78%, and previous cardiac surgery (p < 0.001) and multiple sites of infection (p = 0.004) were independent predictors of death.

CONCLUSIONS

Bacteria were the most common causes of severe infections in pediatric heart transplant recipients and were associated with high mortality rates. The risk of acquiring a bacterial infection was highest in the first month post-transplant, and a large proportion of the infections were caused by multidrug-resistant pathogens.

Pediatric Heart Transplantation: Report from a Single Center in China

BACKGROUND

Although heart transplantation (HTx) has become a standard therapy for end-stage heart diseases, experience with pediatric HTx is limited in China. In this article, we will try to provide the experience with indications, complications, perioperative management, immunosuppressive therapy, and survival for pediatric HTx based on our clinical work.

METHODS

This is a retrospective chart review of the pediatric patients undergoing HTx at Department of Cardiovascular Surgery of Union Hospital from September 2008 to December 2014. We summarized the indications, surgical variables, postoperative complications, and survival for these patients.

RESULTS

Nineteen pediatric patients presented for HTx at Union Hospital of Tongji Medical College, of whom 10 were male. The age at the time of transplantation ranged from 3 months to 18 years (median 15 years). Patient weight ranged from 5.2 kg to 57.0 kg (median 38.0 kg). Pretransplant diagnosis included cardiomyopathy (14 cases), complex congenital heart disease (3 cases), and tumor (2 cases). All recipients received ABO-compatible donor hearts. Postoperative complications occurred in 12 patients, including cardiac dysfunction, arrhythmia, pulmonary infection, renal dysfunction, and rejection. Two of them experienced cardiac failure and required extracorporeal membrane oxygenation. The immunosuppression regimen was comprised of prednisone, a calcineurin inhibitor, and mycophenolate. All patients recovered with New York Heart Association (NYHA) Class I-II cardiac function and were discharged. Only one patient suffered sudden death 19 months after transplantation.

CONCLUSION

Orthotopic HTx is a promising therapeutic option with satisfying survival for the pediatric population in China with end-stage heart disease.

Beta-blockers for congestive heart failure in children

BACKGROUND

Beta-blockers are an essential part of standard therapy in adult congestive heart failure and therefore, are expected to be beneficial in children. However, congestive heart failure in children differs from that in adults in terms of characteristics, aetiology, and drug clearance. Therefore, paediatric needs must be specifically investigated. This is an update of a Cochrane review previously published in 2009.

OBJECTIVES

To assess the effect of beta-adrenoceptor-blockers (beta-blockers) in children with congestive heart failure.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and LILACS up to November 2015. Bibliographies of identified studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised, controlled, clinical trials investigating the effect of beta-blocker therapy on paediatric congestive heart failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and assessed data from the included trials.

MAIN RESULTS

We identified four new studies for the review update; the review now includes seven studies with 420 participants. Four small studies with 20 to 30 children each, and two larger studies of 80 children each, showed an improvement of congestive heart failure with beta-blocker therapy. A larger study with 161 participants showed no evidence of benefit over placebo in a composite measure of heart failure outcomes. The included studies showed no significant difference in mortality or heart transplantation rates between the beta-blocker and control groups. No significant adverse events were reported with beta-blockers, apart from one episode of complete heart block. A meta-analysis of left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) data showed a very small improvement with beta-blockers.However, there were vast differences in the age, age range, and health of the participants (aetiology and severity of heart failure; heterogeneity of diagnoses and co-morbidities); there was a range of treatments across studies (choice of beta-blocker, dosing, duration of treatment); and a lack of standardised methods and outcome measures. Therefore, the primary outcomes could not be pooled in meta-analyses.

AUTHORS' CONCLUSIONS

There is not enough evidence to support or discourage the use of beta-blockers in children with congestive heart failure, or to propose a paediatric dosing scheme. However, the sparse data available suggested that children with congestive heart failure might benefit from beta-blocker treatment. Further investigations in clearly defined populations with standardised methodology are required to establish guidelines for therapy. Pharmacokinetic investigations of beta-blockers in children are also required to provide effective dosing in future trials.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Clinical predictors of autoimmune and severe atopic disease in pediatric heart transplant recipients

Autoimmune and allergic diseases cause morbidity and diminished quality of life in pediatric organ transplant recipients. We hypothesize that younger age at transplantation and immunosuppression regimen play a role in the development of immune-mediated disease following heart transplant. A single institution retrospective review identified all patients undergoing heart transplant at ≤18 yr of age from 1987 to 2010 who survived ≥1 yr. Using medical record and database review, patients were evaluated for development of autoimmune or severe allergic disease. Of 129 patients who met criteria, seven patients (5.4%) with autoimmune or severe atopic disease were identified. Immune-mediated diseases included inflammatory bowel disease (n = 3), eosinophilic esophagitis/colitis (n = 4), and chronic bullous disease of childhood (n = 1). Patients <1 yr of age at transplant were at greater risk of developing autoimmune disease than patients 1-18 yr at transplant (OR = 9.3, 95% CI 1.1-79.2, p = 0.02). All affected patients underwent thymectomy at <1 yr of age (7/71 vs. 0/58, p = 0.02). In our experience, heart transplantation in infancy is associated with the development of immune-mediated gastrointestinal and dermatologic diseases. Further study is needed to determine risk factors for the development of immune-mediated disease to identify best practices to decrease incidence.

Heart transplantation for congenital heart disease in the first year of life

Successful infant heart transplantation has now been performed for over 25 years. Assessment of long term outcomes is now possible. We report clinical outcomes for322 patients who received their heart transplant during infancy. Actuarial graft survival for newborn recipients is 59% at 25 years. Survival has improved in the most recent era. Cardiac allograft vasculopathy is the most important late cause of death with an actuarial incidence at 25 years of 35%. Post-transplant lymphoma is estimated to occur in 20% of infant recipients by25 years. Chronic kidney disease grade 3 or worse is present in 31% of survivors. The epidemiology of infant heart transplantation has changed through the years as the results for staged repair improved and donor resources remained stagnant. Most centers now employ staged repair for hypoplastic left heart syndrome and similar extreme forms of congenital heart disease. Techniques for staged repair, including the hybrid procedure, are described. The lack of donors is described with particular note regarding decreased donors due to newer programs for appropriate infant sleep positioning and infant car seats. ABO incompatible donors are a newer resource for maximizing donor resources, as is donation after circulatory determination of death and techniques to properly utilize more donors by expanding the criteria for what is an acceptable donor. An immunological advantage for the youngest recipients has long been postulated, and evaluation of this phenomenon may provide clues to the development of accommodation and/or tolerance.

Association of genetic polymorphisms and risk of late post-transplantation infection in pediatric heart recipients

BACKGROUND

Late infections are common causes of morbidity and mortality after pediatric heart transplantation. In this multicenter study from 6 centers, we investigated the association between genetic polymorphisms (GPs) in immune response genes and late post-transplantation infections in 524 patients.

METHODS

Late infection was defined as a clinical infectious process occurring >60 days after transplantation and requiring hospitalization, intravenous antimicrobial therapy, or a life-threatening infection requiring oral therapy. All patients provided a blood sample for GP analyses of 18 GPs in cytokine, growth factor, and effector molecule genes by single specific primer-polymerase chain reaction and/or sequencing. Significant associations in univariable analyses were tested in multivariable Cox regression models.

RESULTS

Late infection was common, with 48.7% of patients experiencing ≥ 1 late infection, 25.2% had ≥ 1 late bacterial infection, and 30.5% had ≥ 1 late viral infection. Older age at transplantation was a protective factor for late infection, both bacterial and viral (hazard ratio [HR] 0.89-0.92 per 1-year age increase, p < 0.001). Adjusting for age, race, and transplant etiology, late bacterial infection was associated with HMOX1 A+326G AG and GG genotypes (HR, 2.41, 95% confidence interval [CI] 1.35-4.30; p = 0.003) and GZMB A-295G AA genotype (HR, 1.47; 95% CI; 1.03-2.1; p = 0.036). Late viral infection was associated with FAS A-670G GG genotype (HR, 1.42; 95% CI, 1.00-2.00; p = 0.050) in the adjusted model and with CTLA4 A+49G AA and AG genotypes (HR, 1.49; 95% CI, 1.02-2.19; p = 0.041) in univariable analysis.

CONCLUSION

We found an association between late bacterial infection and GP of HMOX1, which may control macrophage activation. A weaker association was also found between late viral infection and GP of CTLA4, a regulator of T-cell activation. This represents progress toward understanding the clinical and genetic risk factors of outcomes after transplantation.

Heart transplantation in children

In the last 40 years, orthotopic heart transplantation has been established as a realistic treatment strategy for infants and children with severe forms of congenital heart disease and cardiomyopathy. The evaluation, management, and outcomes of these patients have continued to improve. These achievements have advanced pediatric cardiac transplantation and allowed more attention to be focused on improving quality of life after transplantation and reducing the long-term complications.

Lessons from cardiac transplantation in infancy

Besides correcting devastating pathophysiology, cardiac transplantation in infancy offers an incomparable model for exploring the structure and function of the immune system. Infants and young children have relatively few memory B cells and T cells. Hence, the response of the young to allotransplantation better represents a primary immune response and may be better suited to testing spontaneous tolerance. Those who undergo cardiac transplantation in infancy are also unique because they are often subjected to thymectomy and depletion of mature T cells. These subjects can have a dramatic contraction of T cell diversity, allowing the testing of how diversity contributes to function.

Update on infectious diseases in pediatric solid organ transplantation

PURPOSE OF REVIEW

Numerous recent advances have been made in the field of infectious diseases and pediatric solid organ transplant.

RECENT FINDINGS

Although many studies contain somewhat small cohorts of individuals, when summarized together they contribute significantly to our knowledge about pediatric solid organ transplant, especially regarding risk factors for infection, management of BK virus nephropathy, the use of live viral vaccines, and consideration for rare infections as well as donor-derived infections.

SUMMARY

In sum, these recent advances in infection in the field of pediatric solid organ transplant will help decrease infection, thus improving morbidity and mortality, as well as transplant outcomes, especially by decreasing direct (graft injury) and indirect (immune upregulation) effects on organ transplantation. This review will focus on recent advances in the field of infectious diseases in pediatric solid organ transplant by highlighting some of the most important and interesting articles in the field within the past few years.

Beta-blockers for congestive heart failure in children

BACKGROUND

Beta-blockers are an essential part of standard therapy in adult congestive heart failure and are therefore also expected to be beneficial in children. However, congestive heart failure in children differs strongly from that in adults in terms of characteristics and aetiology; also, an increased drug clearance has been reported. Paediatric needs have therefore to be specifically investigated.

OBJECTIVES

To assess the effect of beta-adrenoceptor-blockers in children with congestive heart failure.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 4 2007), MEDLINE (1966 to January 2008), EMBASE (1980 to January 2008), and LILACS (1980 to January 2008). Bibliographies of identified studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised, controlled clinical trials investigating the effect of beta-blocker therapy on paediatric congestive heart failure.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted and assessed data from the included trials.

MAIN RESULTS

Three studies with an overall number of 203 participants were identified. Two small studies, with 20 and 22 children respectively, showed an improvement of congestive heart failure, while a larger study with 161 participants showed no evidence of benefit over placebo in the composite measure of heart failure outcomes which was the main outcome measure of the trial (56% improvement in both the placebo and the treatment group, p=0.74). However, study populations showed vast differences with regard to treatment (choice of beta-blocker, dosing, duration of treatment), age and age range of the participants and in particular with regard to condition (aetiology and severity of heart failure; homogeneity of condition in the study population). In addition methods and outcome measures differed strongly and were not standardised. The results can therefore not be compared against each other.

AUTHORS' CONCLUSIONS

There are not enough data to recommend or discourage the use of beta-blockers in children with congestive heart failure. Further investigations in clearly defined populations with standardised methodology are required to establish guidelines for therapy. Pharmacokinetic investigations of beta-blockers in children are required to provide effective dosing in future trials.