Randomized clinical trial of tacrolimus- vs cyclosporine-based immunosuppression in pediatric heart transplantation: preliminary results at 15-month follow-up

Clinical approach to acute cellular rejection from the pediatric heart transplant society

BACKGROUND

Early detection of cardiac allograft rejection is crucial for post-transplant graft survival. Despite the progress made in immunosuppression strategies, acute cellular rejection remains a serious complication during and after the first post-transplant year, and there is a continued lack of consensus regarding its treatment, especially in pediatric transplant patients.

METHODS

An open request was placed via the listserv to the membership of the Pediatric Heart Transplant Society (PHTS). Along with a broad literature search, numerous institutional protocols were pooled, analyzed and consolidated. A clinical approach document was generated highlighting areas of consensus and practice variation.

RESULTS

The clinical approach document divides cellular rejection by International Society for Heart and Lung Transplantation grades and provides management strategies for each, including persistent cellular rejection.

CONCLUSIONS

Cellular rejection treatment can be tailored to the clinical status, graft function, and the grade of cellular rejection. A case of mild and asymptomatic rejection may not require treatment, whereas a higher-grade rejection or rejection with graft dysfunction or hemodynamic compromise may require aggressive intravenous therapies, changes to maintenance immunosuppression therapy and augmented surveillance.

Heart Transplantation for Pediatric and Congenital Cardiac Disease: A Comparison of Two Eras over 23 Years and 188 Transplants at a Single Institution

BACKGROUND

To assess changes in patterns of practice and outcomes over time, we reviewed all patients who underwent heart transplantation (HTx) at our institution and compared two consecutive eras with significantly different immunosuppressive protocols (cohort 1 [80 HTx, June 1995-June 2006]; cohort 2 [108 HTx, July 2006-September 2018]).

METHODS

Retrospective study of 180 patients undergoing 188 HTx (June 1995-September 2018; 176 first time HTx, 10 second HTx, and 2 third HTx). In 2006, we commenced pre-HTx desensitization for highly sensitized patients and started using tacrolimus as our primary postoperative immunosuppressive agent. The primary outcome was mortality. Survival was modeled by the Kaplan-Meier method. Univariable and multivariable Cox proportional hazard models were created to identify prognostic factors for survival.

RESULTS

Our 188 HTx included 18 neonates, 85 infants, 83 children, and 2 adults (>18 years). Median age was 260.0 days (range: 5 days-23.8 years). Median weight was 7.5 kg (range: 2.2-113 kg). Patients in cohort 1 were less likely to have been immunosensitized preoperatively (12.5% vs 28.7%, P = .017). Nevertheless, Kaplan-Meier analysis suggested superior survival in cohort 2 (P = .0045). Patients in cohort 2 were more likely to be alive one year, five years, and ten years after HTx. Multivariable analysis identified the earlier era (hazard ratio [HR] [95% confidence interval] for recent era = 0.32 [0.14-0.73]), transplantation after prior Norwood operation (HR = 4.44 [1.46-13.46]), and number of prior cardiac operations (HR = 1.33 [1.03-1.71]) as risk factors for mortality.

CONCLUSIONS

Our analysis of 23 years of pediatric and congenital HTx reveals superior survival in the most recent 12-year era, despite the higher proportion of patients with elevated panel reactive antibody in the most recent era. This improvement was temporally associated with changes in our immunosuppressive strategy.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Immune Therapy

OBJECTIVE

In this Consensus Statement, we review the etiology and pathophysiology of inflammatory processes seen in critically ill children with cardiac disease. Immunomodulatory therapies aimed at improving outcomes in patients with myocarditis, heart failure, and transplantation are extensively reviewed.

DATA SOURCES

The author team experience and along with an extensive review of the medical literature were used as data sources.

DATA SYNTHESIS

The authors synthesized the data in the literature to present current immumodulatory therapies. For each drug, the physiologic rationale, mechanism of action, and pharmacokinetics are synthesized, and the evidence in the literature to support the therapy is discussed.

CONCLUSIONS

Immunomodulation has a crucial role in the treatment of certain pediatric cardiac diseases. Immunomodulatory treatments that have been used to treat myocarditis include corticosteroids, IV immunoglobulin, cyclosporine, and azathioprine. Contemporary outcomes of pediatric transplant recipients have improved over the past few decades, partly related to improvements in immunomodulatory therapy to prevent rejection of the donor heart. Immunosuppression therapy is commonly divided into induction, maintenance, and acute rejection therapy. Common induction medications include antithymocyte globulin, muromonab-CD3, and basiliximab. Maintenance therapy includes chronic medications that are used daily to prevent rejection episodes. Examples of maintenance medications are corticosteroids, cyclosporine, tacrolimus, sirolimus, everolimus, azathioprine, and mycophenolate mofetil. Rejection of the donor heart is diagnosed either by clinically or by biopsy and is treated with intensification of immunosuppression.

Does the calcineurin inhibitor have influence on cytomegalovirus infection in heart transplantation?

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in heart transplant (HTx). Our aim was to analyze the rate of CMV infection in HTx patients receiving treatment with cyclosporine (CsA) or tacrolimus (Tac). Ninety-five patients were randomized to receive either CsA (53.7%) or Tac (46.3%). We performed prophylaxis with valganciclovir in patients with the highest risk of CMV infection. We considered CMV infection as an increased viral load or the presence of CMV in histological samples. We analyzed baseline characteristics, CMV infection, and other complications. Event-free rates were calculated using the Kaplan-Meier method. There were no significant differences in baseline characteristics between both groups. CMV infection was detected in 31.6% of patients (in 66.7% due to asymptomatic replication). The group treated with Tac had a lower rate of CMV infection (15.9% vs. 45.1%, p = 0.002) and longer CMV infection-free survival time (1440 vs. 899 d, p = 0.001). No differences were observed in the complications analyzed in both groups. The independent risk factors for infection identified in the multivariate analysis were treatment with CsA and bacterial infections. This was the first study to demonstrate a lower rate of CMV infection in patients treated with Tac vs. those treated with CsA after HTx.

Postoperative care of the transplanted patient

The successful delivery of optimal peri-operative care to pediatric heart transplant recipients is a vital determinant of their overall outcomes. The practitioner caring for these patients must be familiar with and treat multiple simultaneous issues in a patient who may have been critically ill preoperatively. In addition to the complexities involved in treating any child following cardiac surgery, caretakers of newly transplanted patients encounter multiple transplant-specific issues. This chapter details peri-operative management strategies, frequently encountered early morbidities, initiation of immunosuppression including induction, and short-term outcomes.

Pediatric heart transplantation: demographics, outcomes, and anesthetic implications

The evolving demographics, outcomes, and anesthetic management of pediatric heart transplant recipients are reviewed. As survival continues to improve, an increasing number of these patients will present to our operating rooms and sedation suites. It is therefore important that all anesthesiologists, not only those specialized in cardiac anesthesia, have a basic understanding of the physiologic changes in the transplanted heart and the anesthetic implications thereof.

Strategies to prevent cellular rejection in pediatric heart transplant recipients

Despite more than 40 years' experience in pediatric heart transplantation, cellular rejection remains a significant cause of morbidity and mortality. In this review, strategies and agents to prevent acute cellular rejection are discussed. Strategies to prevent rejection are divided into two phases - induction and maintenance therapies. Currently, the most commonly used induction agents are polyclonal antibodies (rabbit or equine antithymocyte globulin) and interleukin-2 receptor antibodies (daclizumab or basiliximab). Induction therapies have reduced early rejection, are renal sparing, and can reduce corticosteroid exposure, but have not yet been shown to have a longer term survival benefit. Multiple maintenance immunosuppressants are available. Nearly all regimens include a calcineurin inhibitor (either ciclosporin [cyclosporine] or tacrolimus). Most combinations in pediatric heart transplantation include an antiproliferative agent (azathioprine, mycophenolate mofetil or, less commonly, sirolimus). Everolimus has seen increasing use in adult heart transplant patients in Europe but, to date, its use is rare in pediatric heart transplantation. The use of corticosteroids as a third agent is still common, but strategies to avoid or minimize their use are increasing. The 'best' combination of therapies varies between studies. By gaining a better understanding of individuals' genetic and environmental risk factors, we may in the future be able to better predict the course of cardiac allografts and enhance our ability to tailor immunosuppression to individual patient variables with the ultimate goal of inducing a state of immune tolerance.

Tacrolimus versus cyclosporine as primary immunosuppression after heart transplantation: systematic review with meta-analyses and trial sequential analyses of randomised trials

PURPOSE

We conducted a systematic review of randomized trials to compare the benefits and harms of tacrolimus versus cyclosporine as primary immunosuppression after heart transplantation.

METHODS AND RESULTS

We searched electronic databases and bibliographies up to April 2010. Our review followed the Cochrane and PRISMA guidelines. The meta-analysis included 10 randomized trials with 952 patients. Tacrolimus was significantly superior to cyclosporine (both formula-combined) with regard to hypertension (relative risk [RR] 0.8; 95% confidence interval [CI] 0.69-0.93, p = 0.003), hyperlipidaemia (RR 0.57; 95% CI 0.44-0.74, p < 0.0001), hirsutism (RR 0.17 95% CI 0.04-0.62, p = 0.008), and gingival hyperplasia (RR 0.07 95% CI 0.01-0.37, p = 0.002). No significant differences between the two calcineurin inhibitors were found with regard to acute rejections causing haemodynamic instability, diabetes, renal dysfunction, infection, malignancy, or neurotoxicity. Tacrolimus was significantly superior to microemulsion cyclosporine with regard to mortality (RR 0.64; 95% CI 0.42-0.96, p = 0.03), acute severe biopsy-proven rejection (RR 0.71; 95% CI 0.56-0.90, p = 0.004), hyperlipidaemia (RR 0.57; 95% CI 0.41-0.79, p = 0.0009), hirsutism (RR 0.17 95% CI 0.04-0.62, p = 0.008), and gingival hyperplasia (RR 0.07; 95% CI 0.01-0.37, p = 0.002). Tacrolimus was significantly superior to oil-based cyclosporine with regard to hypertension (RR 0.66; 95% CI 0.54-0.80, p < 0.0001), and hyperlipidaemia (RR 0.57; 95% CI 0.38-0.87, p = 0.009).

CONCLUSION

Tacrolimus seems to be superior to cyclosporine in heart transplant patients with regard to hypertension, hyperlipidaemia, gingival hyperplasia and hirsutism. In addition, tacrolimus seems to be superior to microemulsion cyclosporine in heart transplant patients with regard to a number of outcomes, including death. More trials with a low risk of bias are needed to determine if the results of the present meta-analysis can be confirmed.

Decline in rejection in the first year after pediatric cardiac transplantation: a multi-institutional study

BACKGROUND

Rejection is a major cause of morbidity and mortality after pediatric heart transplantation (HTx). Survival after pediatric HTx has improved over time, but whether there has been an era-related improvement in the occurrence of allograft rejection is unknown.

METHODS

The Pediatric Heart Transplant Study (PHTS) database was queried for patients who underwent HTx from January 1993 to December 2005 to determine the incidence of rejection and identify factors associated with the first episode of rejection in the first year after HTx.

RESULTS

Data were reviewed in 1,852 patients from 36 centers. The incidence of rejection declined over 13 years at a rate of -2.58 +/- 0.41 (p < 0.001) from approximately 60% to 40% (p < 0.001). The mean number of episodes of rejection also significantly fell at a rate of -0.05 +/- 0.01 per patient/year from 1.19 to 0.66 (p < 0.001). The incidence of rejection with hemodynamic compromise and death from rejection did not change. Multivariate analysis for the risk of a first rejection episode demonstrated decreased risk of rejection with later year of HTx (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.85-0.91; p < 0.001) and use of mechanical support (OR, 0.65; 95% CI, 0.42-0.99; p = 0.046). Increased risk of rejection was associated with positive donor-specific crossmatch (OR, 1.85; 95% CI, 1.18-2.88; p = 0.007) and older recipient age (OR, 1.05; 95% CI, 1.02-1.07; p < 0.001).

CONCLUSIONS

Although the overall incidence and prevalence of rejection has substantially decreased over time in pediatric HTx recipients in the first year after HTx, the rate of rejection with hemodynamic compromise or death from rejection remains unchanged.

The profile of renal function over time in a cohort of pediatric heart transplant recipients

To assess the burden over time of renal dysfunction in pediatric heart transplant patients using an objective measure on an annual basis for serial comparison. GFR was measured at regular interval by nuclear medicine scintigraphy. Results were analyzed in relation to age, time post-transplantation, gender, and average calcineurin-inhibitor dose for the first two months post-transplantation. Results were compared with cGFR using the Schwartz equation. A total of 91 patients (56 males) transplanted between 1990 and 2004 underwent 373 GFR measurements. Median age at transplantation was 3.3 yr (birth - 17.8). Median first GFR at 0.7 yr (0.1-4.1) post-transplant was normal (94 mL/kg/1.73 m(2)). Freedom from at least mild renal insufficiency was 84% and 33% at one and five years post-transplant. Females had better renal function early post-transplant (GFR 105 mL/min/1.73 m(2)) but an increased probability of an abnormal GFR over time. Higher calcineurin inhibitor dose in the first two months post-transplantation was associated with an increasing probability of an abnormal GFR over time. The cGFR overestimated the measured GFR by 33 +/- 26 mL/kg/1.73 m(2). Renal insufficiency is an important morbidity after pediatric transplantation with the majority of patients experiencing at least mild renal dysfunction. Calculated GFR significantly underestimates the burden of renal insufficiency in this patient population.

Tacrolimus versus cyclosporine microemulsion for heart transplant recipients: a meta-analysis

BACKGROUND

Tacrolimus and cyclosporine microemulsion are the 2 major immunosuppressants for heart transplantation. Several studies have compared these 2 drugs, but the outcomes were not consistent. This meta-analysis of randomized controlled trials compared the beneficial and harmful effects of tacrolimus and microemulsion cyclosporine for heart transplant recipients.

METHODS

Electronic databases and manual bibliography searches were conducted. A meta-analysis was performed of all randomized controlled trials comparing tacrolimus with cyclosporine microemulsion as primary immunosuppression for heart transplant recipients. Data for mortality, acute rejection, withdrawals, and adverse events were extracted. The combined results of the data of the randomized controlled trials were summarized as relative risk with 95% confidence intervals.

RESULTS

The study assessed 7 randomized controlled trials including 885 patients. There was no difference in mortality at 1 year between recipients treated with tacrolimus and cyclosporine microemulsion. Tacrolimus-treated patients had less acute rejection risk at 6 months and 1 year. Fewer patients stopped tacrolimus than cyclosporine microemulsion. The rate of new-onset diabetes mellitus requiring insulin treatment was higher with tacrolimus. More post-transplantation hypertension occurred with cyclosporine microemulsion. The groups had comparable incidences of malignancy and renal failure needing dialysis.

CONCLUSIONS

The use of tacrolimus as primary immunosuppressant for heart transplant recipients results in comparable survival and a significant reduction in acute rejection compared with cyclosporine microemulsion.

The first year post-heart transplantation: use of immunosuppressive drugs and early complications

A large number of heart transplants are performed annually in different transplant centers in the United States. This is partly because of the improved survival of patients who undergo cardiac transplantation, thus making it a more viable option in the management of end-stage heart failure. The survival benefit after heart transplantation is a result of newer immunosuppressive drug regimens and a better understanding of their effects and interactions. Several studies, mostly involving a small number of patients, describe use and comparison of the many distinct immunosuppressive drugs available to date. Interestingly, many transplant centers perform in-house typical induction treatment regimens because of their own experience and intra-institutional preference. This review summarizes current practices of immunosuppressive drug therapy in the first year post-heart transplant based on the available clinical evidence and discusses future options of heart transplant immunosuppressive drug therapies.

A randomized controlled trial of tacrolimus versus cyclosporine after lung transplantation

BACKGROUND

The optimal maintenance immunosuppressive regimen after lung transplantation is uncertain.

METHODS

We conducted a randomized controlled trial of tacrolimus versus cyclosporine in combination with azathioprine and prednisone after lung transplantation. Ninety adults were randomized to tacrolimus (n = 44) or cyclosporine (n = 46). The primary end point was a composite of a cumulative acute rejection A score of 3 or higher, a cumulative lymphocytic bronchitis B score of 4 or higher, or the onset of bronchiolitis obliterans syndrome (BOS) stage 0-p.

RESULTS

Recipients randomized to cyclosporine were significantly more likely to develop the primary end point than those randomized to tacrolimus. During the study period, the primary end point developed in 39 of 46 cyclosporine subjects compared with 24 of 44 tacrolimus subjects (p = 0.002); acute rejection or lymphocytic bronchitis end points developed in 29 of 46 cyclosporine subjects compared with 18 of 44 tacrolimus subjects (p = 0.036). Furthermore, BOS stage 0-p was more likely to develop in the cyclosporine group than in the tacrolimus group, but this was not statistically significant (log-rank p = 0.1). In addition, there was a trend to a higher incidence of diabetes among those in the tacrolimus group, but there was no significant difference in graft survival or the total number of infections, or in the incidence of hypertension, chronic kidney disease, or cancer between the 2 groups.

CONCLUSIONS

Tacrolimus is associated with a lower burden of acute rejection and lymphocytic bronchitis and a trend to a greater freedom from BOS stage 0-p than cyclosporine after lung transplantation.

Tacrolimus: in heart transplant recipients

Tacrolimus is a calcineurin inhibitor recently approved in the US and throughout the EU for the prevention of allograft rejection in heart transplant recipients. It is commonly administered orally for long-term immunosuppression. The incidence of mild to severe acute rejection in the first 6 months following heart transplantation was significantly lower in tacrolimus recipients than in ciclosporin recipients (54% vs 66%) in a large, phase III trial conducted in Europe. A large, phase III trial conducted in the US did not show a significant difference between tacrolimus and ciclosporin in the incidence of severe rejection or haemodynamic compromise rejection requiring treatment within the first 6 months post-transplant (22% vs 32%), but did show a significant difference in the incidence at 1 year (23% vs 37%). In phase III trials, 1-year patient survival was similar between tacrolimus and ciclosporin recipients in the EU (93% vs 92%) and the US (95% vs 90%). Tacrolimus was shown to be effective in the prevention of rejection in paediatric and African American heart transplant recipients. The tolerability profile of tacrolimus in heart transplant recipients was broadly similar to that of ciclosporin, although tacrolimus was usually associated with lower incidences of post-transplant hypertension and dyslipidaemia.

Cellular pharmacodynamics of immunosuppressive drugs for individualized medicine

The therapeutic effects of immunosuppressive drugs are known to deviate largely between patients, but efficient strategies for the differentiation of patients who show clinical resistance to immunosuppressive therapies have not been established. Accordingly, a considerable number of patients receive treatment with immunosuppressive drugs despite the onset of serious side effects and poor responses. Cellular pharmacodynamics of immunosuppressive drugs in vitro using peripheral lymphocytes derived from each patient, an attractive way to distinguish resistant patients, is respected and has been applied to the carrying out of individualized immunosuppressive therapy. In this article, I summarize experimental procedures for assaying immune cell responses to immunosuppressive drugs in vitro, and highlight the relationship between cellular sensitivity to immunosuppressive drugs and the therapeutic efficacy of drugs in organ transplantation and several immunological disorders. I will also overview the molecular mechanisms and genetic bases for cellular and clinical resistance to immunosuppressive drugs. Lastly, the future clinical prospects for the application of in vitro drug sensitivity tests for "patient-tailored" immunosuppressive therapies are discussed.

Heart and lung transplantation in children

During the past two decades, several advances have resulted in marked improvement in medium-term survival for infants and children undergoing heart transplantation. Unfortunately, progress has been less dramatic in the field of lung and heart-lung transplantation, where there is little evidence of improved outcomes. The procedures remain palliative and all transplant recipients are at risk for the adverse effects of non-specific immunosuppression, including infections, lymphoproliferative disorders, and non-lymphoid malignancies. In addition, current immunosuppressive agents have narrow therapeutic windows and exhibit a wide array of organ toxicities, posing special challenges for the young patient who must endure life-long immunosuppression. New immunosuppressive regimens have lowered the rates of acute rejection but appear to have had relatively little impact on the incidence of chronic rejection, the principal cause of late graft loss. The ultimate goal is to induce a state of donor-specific tolerance, wherein the recipient will accept the allograft indefinitely without the need for long-term immunosuppression. This quest is currently being realised in animal models of solid organ transplantation, and offers great hope for children undergoing heart and lung transplantation in the future.

Leukocyte Suppression is Associated with Improved Clinical Outcomes in Children’s Status after Orthotopic Heart Transplantation

BACKGROUND

Leukocyte suppression is a sequela of immunosuppressive therapy after orthotopic heart transplantation and may result in discontinuation of anti-proliferative agents. Clinical outcomes in this patient population have not been well delineated.

METHODS

This study was a retrospective review of children who underwent orthotopic heart transplantation at our institution from 1986 to 2003. Leukocyte suppression was defined as a white blood cell count <5,000, prompting the withdrawal of anti-proliferative agents. The population was divided into 2 groups, leukosuppressed (LS) and non-leukosuppressed (NLS), and their clinical outcomes were compared.

RESULTS

The study included 109 patients, of which 44 (40%) became leukosuppressed. The 2 groups were similar regarding demographic data and initial management. The LS Group had a significantly decreased incidence of rejection, being 7 times less likely to have recurrent rejection (p = 0.001). The median time to rejection was 0.8 +/- 0.6 years for the NLS Group, whereas the median time to rejection was not yet reached at 17 years for the LS Group. The LS Group also tended toward a decreased incidence of retransplantation or death (p = 0.06). The organ "half-life" in the NLS Group was 7.5 years vs 12.5 years in the LS Group. There was no difference between the 2 groups in regards to other adverse effects of immunosuppression.

CONCLUSIONS

Children who have undergone orthotopic heart transplantation and subsequently become leukosuppressed have a lower incidence of rejection and a tendency toward less organ loss than children who do not become leukosuppressed, without having an increased incidence of adverse side effects.