First experience with basiliximab in pediatric liver graft recipients

Survival Time to Biopsy-Proven Acute Rejection and Tacrolimus Adverse Drug Reactions in Pediatric Liver Transplantation

BACKGROUND

Despite advances in surgical procedures and the optimization of immunosuppressive therapies in pediatric liver transplantation, acute rejection (AR) and serious adverse drug reaction (ADR) to tacrolimus still contribute to morbidity and mortality. Identifying risk factors of safety and efficacy parameters may help in optimizing individual immunosuppressive therapies. This study aimed to identify peritransplant predictors of AR and factors related to the risk of ADR to tacrolimus in a large Latin American cohort of pediatric liver transplant patients.

METHODS

We performed a retrospective cohort study in a pediatric liver transplant population (n = 72). Peritransplant variables were collected retrospectively including demographic, clinical, laboratory parameters, genomic (CYP3A5 donor and recipients polymorphism), and tacrolimus trough concentrations (C0) over a 2-year follow-up period. Variability in tacrolimus C0 was calculated using percent coefficient of variation and tortuosity. ADR- and AR-free survival rates were calculated using the Kaplan-Meier method, and risk factors were identified by multivariate Cox regression models.

RESULTS

Cox-proportional hazard models identified that high tortuosity in tacrolimus C0 was associated with an 80% increased risk of AR [hazard ratio (HR), 1.80; 95% confidence interval (CI), 1.01-3.22; P < 0.05], whereas steroid in maintenance doses decreased this risk (HR, 0.56; 95% CI, 0.31-0.99; P < 0.05). Forty-six patients experienced at least one ADR including hypomagnesemia, nephrotoxicity, hypertension, malignancies, and tremor as a first event. Multivariate analysis showed that C0 values 10 days before the event (HR, 1.25; 95% CI, 1.21-1.39; P < 0.0001) and CYP3A5 expresser recipients (HR, 2.05; 95% CI, 1.03-4.06; P < 0.05) were independent predictors of ADR.

CONCLUSIONS

Tacrolimus C0 values, its variability, and CYP3A5 polymorphisms were identified as risk factors of AR and tacrolimus ADR. This knowledge may help to control and reduce their incidence in pediatric liver transplant patients. Prospective studies are important to validate these results.

Basiliximab treatment for steroid-resistant rejection in pediatric patients following liver transplantation for acute liver failure

An IL-2 receptor antagonist, basiliximab, decreases the frequency of ACR in liver transplant (LT) recipients as induction therapy. The aim of this study was to evaluate the effectiveness of basiliximab against SRR as rescue therapy in pediatric LT patients with ALF. Forty pediatric ALF patients underwent LT between November 2005 and July 2013. Among them, seven patients suffering from SRR were enrolled in this study. The median age at LT was 10 months (6-12 months). SRR was defined as the occurrence of refractory rejection after more than two courses of steroid pulse therapy. Basiliximab was administered to all patients. The withdrawal of steroids without deterioration of the liver function was achieved in six patients treated with basiliximab therapy without patient mortality, although one patient developed graft loss and required retransplantation for veno-occlusive disease. The pathological examinations of liver biopsies in the patients suffering from SRR revealed severe centrilobular injuries, particularly fibrosis within one month after LT. We demonstrated the effectiveness and safety of rescue therapy consisting of basiliximab for SRR in pediatric LT recipients with ALF.

The role of everolimus in liver transplantation

During the last 5 decades, liver transplantation has witnessed rapid development in terms of both technical and pharmacologic advances. Since their discovery, calcineurin inhibitors (CNIs) have remained the standard of care for immunosuppression therapy in liver transplantation, improving both patient and graft survival. However, adverse events, particularly posttransplant nephrotoxicity, associated with long-term CNI use have necessitated the development of alternate treatment approaches. These include combination therapy with a CNI and the inosine monophosphate dehydrogenase inhibitor mycophenolic acid and use of mammalian target of rapamycin (mTOR) inhibitors. Everolimus, a 40-O-(2-hydroxyethyl) derivative of mTOR inhibitor sirolimus, has a distinct pharmacokinetic profile. Several studies have assessed the role of everolimus in liver transplant recipients in combination with CNI reduction or as a CNI withdrawal strategy. The efficacy of everolimus-based immunosuppressive therapy has been demonstrated in both de novo and maintenance liver transplant recipients. A pivotal study in 719 de novo liver transplant recipients formed the basis of the recent approval of everolimus in combination with steroids and reduced-dose tacrolimus in liver transplantation. In this study, everolimus introduced at 30 days posttransplantation in combination with reduced-dose tacrolimus (exposure reduced by 39%) showed comparable efficacy (composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, or death) and achieved superior renal function as early as month 1 and maintained it over 2 years versus standard exposure tacrolimus. This review provides an overview of the efficacy and safety of everolimus-based regimens in liver transplantation in the de novo and maintenance settings, as well as in special populations such as patients with hepatocellular carcinoma recurrence, hepatitis C virus-positive patients, and pediatric transplant recipients. We also provide an overview of ongoing studies and discuss potential expansion of the role for everolimus in these settings.

Antibody induction versus corticosteroid induction for liver transplant recipients

BACKGROUND

Liver transplantation is an established treatment option for end-stage liver failure. To date, no consensus has been reached on the use of immunosuppressive T-cell specific antibody induction compared with corticosteroid induction of immunosuppression after liver transplantation.

OBJECTIVES

To assess the benefits and harms of T-cell specific antibody induction versus corticosteroid induction for prevention of acute rejection in liver transplant recipients.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 30 September 2013 together with reference checking, citation searching, contact with trial authors and pharmaceutical companies to identify additional trials.

SELECTION CRITERIA

We included all randomised clinical trials assessing immunosuppression with T-cell specific antibody induction versus corticosteroid induction in liver transplant recipients. Our inclusion criteria stated that participants within each included trial should have received the same maintenance immunosuppressive therapy.

DATA COLLECTION AND ANALYSIS

We used RevMan for statistical analysis of dichotomous data with risk ratio (RR) and of continuous data with mean difference (MD), both with 95% confidence intervals (CIs). We assessed risk of systematic errors (bias) using bias risk domains with definitions. We used trial sequential analysis to control for random errors (play of chance).

MAIN RESULTS

We included 10 randomised trials with a total of 1589 liver transplant recipients, which studied the use of T-cell specific antibody induction versus corticosteroid induction. All trials were with high risk of bias. We compared any kind of T-cell specific antibody induction versus corticosteroid induction in 10 trials with 1589 participants, including interleukin-2 receptor antagonist induction versus corticosteroid induction in nine trials with 1470 participants, and polyclonal T-cell specific antibody induction versus corticosteroid induction in one trial with 119 participants.Our analyses showed no significant differences regarding mortality (RR 1.01, 95% CI 0.72 to 1.43), graft loss (RR 1.12, 95% CI 0.82 to 1.53) and acute rejection (RR 0.84, 95% CI 0.70 to 1.00), infection (RR 0.96, 95% CI 0.85 to 1.09), hepatitis C virus recurrence (RR 0.89, 95% CI 0.79 to 1.00), malignancy (RR 0.59, 95% CI 0.13 to 2.73), and post-transplantation lymphoproliferative disorder (RR 1.00, 95% CI 0.07 to 15.38) when any kind of T-cell specific antibody induction was compared with corticosteroid induction (all low-quality evidence). Cytomegalovirus infection was less frequent in patients receiving any kind of T-cell specific antibody induction compared with corticosteroid induction (RR 0.50, 95% CI 0.33 to 0.75; low-quality evidence). This was also observed when interleukin-2 receptor antagonist induction was compared with corticosteroid induction (RR 0.55, 95% CI 0.37 to 0.83; low-quality evidence), and when polyclonal T-cell specific antibody induction was compared with corticosteroid induction (RR 0.21, 95% CI 0.06 to 0.70; low-quality evidence). However, when trial sequential analysis regarding cytomegalovirus infection was applied, the required information size was not reached. Furthermore, diabetes mellitus occurred less frequently when T-cell specific antibody induction was compared with corticosteroid induction (RR 0.45, 95% CI 0.34 to 0.60; low-quality evidence), when interleukin-2 receptor antagonist induction was compared with corticosteroid induction (RR 0.45, 95% CI 0.35 to 0.61; low-quality evidence), and when polyclonal T-cell specific antibody induction was compared with corticosteroid induction (RR 0.12, 95% CI 0.02 to 0.95; low-quality evidence). When trial sequential analysis was applied, the trial sequential monitoring boundary for benefit was crossed. We found no subgroup differences for type of interleukin-2 receptor antagonist (basiliximab versus daclizumab). Four trials reported on adverse events. However, no differences between trial groups were noted. Limited data were available for meta-analysis on drug-specific adverse events such as haematological adverse events for antithymocyte globulin. No data were available on quality of life.

AUTHORS' CONCLUSIONS

Because of the low quality of the evidence, the effects of T-cell antibody induction remain uncertain. T-cell specific antibody induction seems to reduce diabetes mellitus and may reduce cytomegalovirus infection when compared with corticosteroid induction. No other clear benefits or harms were associated with the use of T-cell specific antibody induction compared with corticosteroid induction. For some analyses, the number of trials investigating the use of T-cell specific antibody induction after liver transplantation is small, and the numbers of participants and outcomes in these randomised trials are limited. Furthermore, the included trials are heterogeneous in nature and have applied different types of T-cell specific antibody induction therapy. All trials were at high risk of bias. Hence, additional randomised clinical trials are needed to assess the benefits and harms of T-cell specific antibody induction compared with corticosteroid induction for liver transplant recipients. Such trials ought to be conducted with low risks of systematic error and of random error.

Immunosuppression in pediatric liver transplantation: are little people different?

1. Children differ from adults in the pharmacokinetics and dynamics of most immunosuppressive agents. 2. A lack of clinical trials continues to be an issue for newer agents. 3. On the basis of clinical case series, mycophenolate mofetil and sirolimus are increasingly being used as renal-sparing agents. 4. In comparison with adults, the recurrence of both viral hepatitis and hepatocellular carcinoma is less of an issue in children. 5. Particular attention should be paid to complete age-appropriate immunization to avoid vaccine-preventable diseases. 6. Paying special attention to adherence and the transition to adult services is essential for minimizing graft loss.

Pediatric liver transplantation

In previous decades, pediatric liver transplantation has become a state-of-the-art operation with excellent success and limited mortality. Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, immunosuppression, and identification and treatment of postoperative complications. The utilization of split-liver grafts and living-related donors has provided more organs for pediatric patients. Newer immunosuppression regimens, including induction therapy, have had a significant impact on graft and patient survival. Future developments of pediatric liver transplantation will deal with long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible. This review describes the state-of-the-art in pediatric liver transplantation.

Current issues in pediatric transplantation

Pediatric solid organ transplantation is so successful that >80% of children will survive to become teenagers and adults. Therefore, it is essential that these children maintain a good quality life, free of significant long-term side effects. While intensive immunosuppressive regimens (containing CsA, tacrolimus, MMF, and steroids) effectively reduce acute or chronic rejection, they can produce long-term side effects including viral infection, renal dysfunction, hypertension, and stunting. The development of effective methods of diagnosis, prevention, and treatment of CMV means that this is no longer a significant cause of mortality, but morbidity remains high. In contrast, infection rates of EBV remain high in EBV-negative pre-transplant patients. However, pre-emptive reduction of immunosuppression or treatment with rituximab or adoptive T-cell therapy is effective in preventing/treating post-transplant lymphoproliferative disease. Recent protocols have concentrated on reducing CsA immunosuppression, to prevent unacceptable cosmetic effects, and to reduce the hypertension, hyperlipidemia, and nephrotoxicity. Both CsA and tacrolimus cause a 30% reduction in renal function, with 4-5% of patients developing severe chronic renal failure. The use of IL-2 inhibitors for induction therapy with low-dose calcineurin inhibitors, in combination with renal-sparing drugs such as MMF or sirolimus for maintenance immunosuppression, should prevent significant renal dysfunction in the future. The concept of steroid-free immunosuppression with IL-2 inhibitors, tacrolimus, and MMF is an attractive option, which may reduce stunting and renal dysfunction. However, these regimens may be associated with the increased development of de-novo autoimmune hepatitis in 2-3% of children. The most important challenge to long-term survival in transplanted children is the management of non-adherence and other adolescent issues, particularly when transferring to adult units, as this is the time when many successful transplant survivors lose their grafts.

Immunosuppression in pediatric solid organ transplantation

This report reviews the immunosuppressive regimens that are used in pediatric transplantation. There are predominant themes developing in the field involving the minimization of the total exposure of immunosuppression through limiting the number of agents and newer pharmacokinetic modeling. Calcineurin inhibitors are the foundation of most immunosuppressive regimens. However, there are new pharmacologic monitoring techniques to reduce the potential for long-term side effects of this class of agents. Although tacrolimus remains one of the mainstays of current protocols, there are strides being made to reduce the patient's long-term exposure to it with transitioning to sirolimus. Corticosteroids are still used predominantly, but there is growing evidence of successful steroid-sparing protocols that are as effective and avoid the chronic morbidity of steroids. Antibody induction therapy remains a standard with clearer evidence of the efficacy of IL-2 receptor antagonists. There is preliminary clinical evidence that polyclonal antibody therapy is efficacious in pediatric transplantation. Future studies will determine the best way to assess the functional immune status of a pediatric transplant recipient to maintain the fine balance and avoid the complications of either excessive or inadequate immunosuppression.

Randomized trial of basiliximab induction versus steroid therapy in pediatric liver allograft recipients under tacrolimus immunosuppression

Avoidance of corticosteroids could be beneficial after pediatric liver transplantation (LTx). To test this hypothesis, we performed a randomized prospective study to compare immunosuppression with tacrolimus (TAC) and steroids versus TAC and basiliximab (BAS) after pediatric LTx. Seventy-two patients were recruited, 36 receiving TAC and steroids and 36 TAC and BAS. The primary endpoint was the occurrence of the first rejection episode. Secondary endpoints were the cumulative incidence and severity of rejection, patient and graft survival, and incidence of adverse events. Overall 1-year patient and graft survival rates were 91.4% and 85.5% in the steroid group, and 88.6% and 80% in the BAS group (p = NS). Patients free from rejection were 87.7% in the BAS group and 67.7% in the steroid group (p = 0.036). The use of BAS was associated with a 63.6% reduction in incidence of acute rejection episodes. Overall incidence of infection was 72.3% in the steroid group and 50% in the BAS group (p = 0.035). We conclude that the combination of TAC with BAS is an alternative to TAC and steroid immunosuppression in pediatric LTx, which allows for a significant reduction in the incidence of acute rejection and infectious complications.

Long-term results of basiliximab induction immunosuppression in pediatric liver transplant recipients

It has been shown that an induction therapy with the monoclonal anti-interleukin-2 receptor antibody basiliximab (Simulect) is capable to reduce the incidence of acute graft rejection in adult and pediatric liver transplantation (Ltx). However, data on long-term results using basiliximab in children post-Ltx are still pending. Therefore, the objective of our study was to report on the long-term results of basiliximab induction therapy in pediatric liver transplant recipients. A total of 54 children received two single doses of basiliximab in addition to cyclosporine and prednisolone following Ltx. We analyzed the incidence of acute and chronic graft rejection that of post-transplant lymphoproliferative disease (PTLD), and patient and graft survival. The follow-up was 22-46 months. The historical control group (matched controls) consisted of 54 patients treated with a cyclosporine and prednisolone dual therapy. Patient survival was 53 of 54 in the treatment group and 51 of 54 in the controls. One patient was retransplanted in the treatment group vs. three patients in the control group. The incidence of acute graft rejection was 16.6% compared with 53.7% in the control group (p < 0.001), that of chronic rejection was comparable in both groups (one of 54 vs. one of 54). The incidence of steroid resistant rejection was four of 54 vs. six of 54 that of PTLD were one of 54 vs. zero of 54. There were no adverse effects observed, which could be related to the antibody treatment. We conclude that basiliximab provides safe and effective induction immunosuppression in pediatric liver graft recipients. Short- and even long-term results are excellent.

Daclizumab induction therapy associated with tacrolimus-MMF has better outcome compared with tacrolimus-MMF alone in pediatric living donor liver transplantation

AIMS

Immunosuppression therapy for the control of immunologic rejection is a key aspect in liver transplantation. The objective of this study was to evaluate induction therapy with daclizumab (DAC) in living donor liver transplantation (LDLT) in children.

METHODS

We compared 2 different immunosuppression protocols in 30 children undergoing LDLT. The patients were divided into 2 groups: 12 patients received tacrolimus with mycophenolate mofetil (TAC-MMF), and 18 patients received tacrolimus with MMF and DAC induction therapy at days 0 and 14 after LDLT (DAC-TAC-MMF). Both groups were similar with regard to age, sex, weight, and indication for liver transplantation. The incidence of biopsy-proved rejection episodes, posttransplantation lymphoproliferative disease (PTLD), and renal dysfunction were evaluated. Tacrolimus levels at posttransplantation day 14 and at 2 months after transplantation were compared in the 2 groups.

RESULTS

Acute rejection episodes were observed in 8 patients in the TAC-MMF group (66%), and none in the DAC-TAC-MMF group (0%; P < .05). Neither PTLD nor renal dysfunction was seen in any patient. Mean Tacrolimus level on posttransplantation day 14 was 10.67 +/- 5.4 ng/mL in the TAC-MMF group and 5.65 +/- 3.6 ng/mL in the DAC-TAC-MMF group (P < .05). After the second month the mean tacrolimus levels were 7.2 +/- 2.9 ng/mL and 6.8 +/- 3.5 ng/mL in the TAC-MMF and DAC-TAC-MMF groups, respectively. (P = NS).

CONCLUSION

Induction therapy with DAC is safe and associated with a lower incidence of rejection episodes among children undergoing LDLT.

Anti-IL-2 receptor antibody vs. polyclonal anti-lymphocyte antibody as induction therapy in pediatric transplantation

Current concerns in pediatric transplantation focus on chronic rejection which commonly leads to graft loss, and on long-term maintenance immunosuppression toxicity. Acute rejection has been associated with the subsequent development of chronic rejection. Therefore, induction therapy may provide potential benefits by preventing early acute rejection episodes and allowing delayed administration of calcineurin inhibitors or steroid avoidance. This review of the literature showed that induction therapy can reduce early and recurrent acute rejection episodes after pediatric solid organ transplantation. Whether this might result in better long-term graft survival has still to be confirmed. However, induction therapy has beneficial effects in high-risk recipients and allows steroid avoidance or calcineurin inhibitor minimization. Because they are very well tolerated, anti-IL-2 receptor antibodies are increasingly preferred to rabbit-antithymocyte globulin, but the former have not yet been proven to be more effective or to have less late toxicity than polyclonal agents. Benefits in early outcome and no increase in adverse events lead to recommend the use of IL-2 receptor antagonists as induction therapy after pediatric organ transplantation.

Basiliximab-chimeric anti-IL2-R monoclonal antibody in pediatric liver transplantation: comparative study

Basiliximab is a monoclonal antibody that binds to the alpha subunit (CD(25)) of the interleukin-2 receptor of activated T lymphocytes. The advantage of basiliximab in organ transplantation is the reduce possibility to calcineurin inhibitor dosages to avoid nephrotoxicity. Basiliximab has significantly reduced the incidence of acute rejection (AR) in renal transplant recipients; however, the results are uncertain in liver transplantation (LT). The objective of this investigation was to assess the effect of basiliximab to prevent AR in the first 6 months after pediatric LT. From March 2000 to October 2001, 32 recipients of a primary orthotopic cadaveric or living donor LT were given basiliximab by intravenous bolus injection on the day of transplantation (day 0) and on day 4. Four children who received one dose were excluded from the study. The rate and the intensity of AR episodes, the incidence of chronic rejection, serum creatinine level, incidence of infections, adverse side effects, and daily oral dosage of cyclosporine (Neoral) to maintain the target blood level of 850 to 1000 mg/dL at C2, 2 hours after the administration, were analyzed in the remaining 28 recipients. Results were compared to those obtained from a matched historical group (n = 28) of similar age, weight, and hepatic diseases distribution. None of the analyzed parameters was statistically significant (P >.05) except for the daily oral dose of cyclosporine (7 to 13 mg/kg/dose, P <.05). In our series, the addition of basiliximab to the immunosuppressive therapy did not reduce the incidence of AR in pediatric LT.

Hypogammaglobulinemia in pediatric liver transplant recipients

Hypogammaglobulinemia has been reported after solid organ transplantation in adults, however immunoglobulin replacement [intravenous immunoglobulins (IVIG)] is only necessary in a minority of affected patients. We here present three pediatric patients with severe post-transplant hypogammaglobulinemia following liver transplantation (LTx) receiving a cyclosporine-based standard immunosuppression. Patient 1 was transplanted at the age of 10 months for biliary atresia. Eight weeks post-Ltx the serum IgG was 1.7 g/L. Patient 2 was transplanted at the age of 12 yr for acute liver failure. Four weeks post-Ltx the IgG dropped to 2.6 g/L. Patient 3 was transplanted at the age of 4 months for biliary atresia. Ten weeks post-Ltx severe hypogammaglobulinemia (IgG < 1.48 g/L) was diagnosed during a severe infectious complication. Patients 1 and 3 received a steroid bolus therapy for acute graft rejection. All patients had normal IgG concentrations prior to Ltx and lymphocyte subsets were post-operatively in the normal range. There was no extensive loss of protein by ascites. IGIV were replaced in the three patients monthly without further complications. In two of the patients (1 and 3) IVIG therapy was discontinued 8 and 10 months after Ltx when the immunosuppression has been reduced and serum IgG concentrations were found in the normal range without further immunoglobulin replacement. Severe hypogammaglobulinemia is a rare phenomenon following pediatric LTx and seems to be mainly caused by immunosuppressive drugs, however, the exact underlying mechanisms are unclear. A screening for hypogammaglobulinemia is useful after pediatric LTx, especially in patients with an intensified immunosuppression. Moreover, further immunologic research in affected patients is necessary.

Double-Blind Comparison of Hepatitis C Histological Recurrence Rate in HCV+ Liver Transplant Recipients Given Basiliximab+Steroids or Basiliximab+Placebo, in addition to Cyclosporine and Azathioprine

BACKGROUND

Hepatitis C virus (HCV) recurrence in HCV+ liver transplant recipients is almost inevitable and may be promoted by immunosuppression. We compared the amount of liver damage with regard to usage of steroids and basiliximab.

METHODS

A total of 140 HCV+ adult liver transplant recipients were randomly allocated to basiliximab + steroids or basiliximab + placebo (plus cyclosporine and azathioprine). Primary endpoint: hepatitis C histological recurrence (liver damage as for Ishak grading score >or=8 by biopsy at 12 months); secondary endpoints: treatment failure (death, graft loss, patient withdrawal), biopsy proven acute rejection (BPAR), treated acute rejection (tAR), allograft and patient survival rates at 12 months.

RESULTS

Any significant difference has been observed in the 12-month hepatitis C histological recurrence rate (41.2% basiliximab + steroids, 37.5% basiliximab + placebo, P = 0.354). The treatment failure rate was significantly higher in basiliximab + steroids (28.8%) than in basiliximab + placebo (15.6%), P = 0.03; the combination test for the evaluation of the joint hypothesis resulted in a borderline nonsignificant overall result (P = 0.059). BPAR rate was significantly lower in the group treated with steroids (24.3% basiliximab + steroids, 39.4% basiliximab + placebo, P = 0.04), while the tAR rate was similar (29.7% basiliximab + steroids and 37.9% basiliximab + placebo). Any significant differences in 1-year graft and patient survival rates have been observed (72.9% and 84.8% basiliximab+steroids; 81.5% and 89.0% basiliximab + placebo).

CONCLUSIONS

Results suggest that steroid-free therapy is associated with a significantly lower treatment failure rate, although histological recurrence rate of hepatitis C is similar in the two groups. This benefit is not offset by an evident increase in graft rejection rate requiring treatment.

Efficacy and Safety of Basiliximab with a Tacrolimus-Based Regimen in Liver Transplant Recipients

BACKGROUND

Induction with monoclonal antibodies for prevention of acute cellular rejection (ACR) may avoid many of the adverse events associated with polyclonal antibodies. Basiliximab, a chimeric monoclonal antibody directed against the alpha-chain of the interleukin 2 receptor (CD25), has been extensively evaluated as an induction therapy for kidney transplant recipients, more frequently in combination with a cyclosporine-based regimen. In this study, we assessed the efficacy and safety of basiliximab in combination with a tacrolimus-based regimen after liver transplantation.

METHODS

Fifty consecutive liver transplants (47 cadaveric donors; 3 living donors) were analyzed. All patients received two 20-mg doses of basiliximab (days 0 and 4 after transplantation) followed by tacrolimus (0.15 mg/kg/day; 10-15 ng/mL target trough levels) and a tapered dose regimen of steroids. Follow-up ranged from 404 to 1,364 days after transplantation (mean 799.89 days, SD+/-257.37; median 796 days).

RESULTS

A total of 88% of patients remained rejection-free during follow-up with an actuarial rejection-free probability of 75% within 3 months. The actuarial patient survival rate at 3 years was 88%, and the graft survival rate was 75%. Twelve (24%) patients experienced one episode of sepsis, requiring temporary reduction of immunosuppressive therapy. There were no immediate side effects associated with basiliximab and no evidence of cytomegalovirus infection or posttransplant lymphoproliferative disorder.

CONCLUSIONS

Basiliximab in combination with a tacrolimus-based immunosuppressive regimen is effective in reducing episodes of ACR and increasing ACR-free survival after liver transplantation. In addition, basiliximab does not increase the incidence of adverse effects or infections.

Evolution of immunosuppression in liver transplantation: contribution of cyclosporine

Liver transplantation has become the standard therapy for patients with end-stage liver disease or acute liver failure, with excellent outcomes in terms of quality of life and length of survival. The use of immunosuppressive agents, without any doubt, has played a crucial role in the establishment of this technique and improved short- and long-term survival rates. Eventually, mortality from acute or chronic rejection may be entirely eliminated. Minimizing the adverse effects of immunosuppressive agents is essential to improve long-term survival and quality of life. In this chapter, we review the history of immunosuppressive agents for liver transplantation with consideration of the pre- and the postcyclosporine eras. We also review the development and contributions of cyclosporine, the excellent outcomes from C2 monitoring, comparisons between the cyclosporine microemulsion and the oil-based formula, as well as between cyclosporine microemulsion versus tacrolimus. In addition, details are provided on the newer immunosuppressive agents: mycophenolate mofetil, sirolimus, and the IL-2 receptor antagonists, as well as agents in development: CAMPATH 1-H, thymoglobulin, everolimus, FT720, and FK778.

The impact of cyclosporine on the development of immunosuppressive therapy for pediatric liver transplantation

Since the introduction of cyclosporine into pediatric liver transplantation remarkable progress in patient and graft survival has been observed: survival rates 60%; acute (60%), steroid-resistant (22%) and chronic rejection (4%); infections (60%); and side effects (20%). Individualization of cyclosporine therapy complements the development of new immunosuppressive agents such as tacrolimus, mycophenolate mofetil, and sirolimus for specific indications. The ultimate goal of transplantation to achieve immunotolerance a waits future progress.

Current status of liver transplantation in children

There are two critical issues on opposite ends of the timeline for patients who are eligible for liver transplantation. On the one hand, the crisis in the cadaveric organ supply makes surviving to transplant ever more risky. On the other hand, patients who receive successful transplants face the consequences of long-term immunosuppression and its potentially life-threatening complications. The donor shortage is forcing difficult decisions that affect all patients who await liver transplantation. It is important to scrutinize carefully the results of all policies that govern allocation and the ethics of the solutions we advocate to ensure that no patient subgroup is being at a disadvantage. Current immunosuppression practices are being challenged by an increasing understanding of the immunologic events triggered by the allograft and the goal to free patients from consequences of a lifetime of immunosuppression. Clinicians can expect, and perhaps require, that new immunosuppressive protocols will address how the planned intervention might be expected to advance the understanding of tolerance mechanisms. As knowledge increases, clinicians can anticipate innovative new immunosuppressive proposals. Calcineurin and steroid-free induction, the use of donor-derived bone marrow infusion, recipient pretreatment, costimulatory blockade, and new antibody induction approaches are all being proposed--often in combination--for clinical trials. Researchers face additional challenges in defining endpoints if the goal is not just the short-term reduction in rejection but the minimization, and eventual discontinuation, of immunosuppressive drugs while maintaining excellent long-term graft function. How much "failure" will be accepted and how will it be defined? How will clinicians interpret liver biopsies if they begin to accept that some lymphocytic infiltrates may be beneficial mediators of the ongoing immune activation necessary for the maintenance of tolerance? How will they adjust immunosuppression practices to the dynamic processes in the immune response that maintain tolerance? Remarkable short-term successes in providing transplants for thousands of children with liver failure have brought these challenges into sharp focus. Clinicians must seek to move the life-giving science of transplantation toward a new goal: providing long lifetimes of excellent graft function with minimal toxicity from immunosuppressive drugs and the hope of freedom from immunosuppression altogether. Pediatric liver recipients, whose grafts have inherent tolerogenic potential and for whom we can anticipate decades of life after transplant, may prove to be an ideal study population to further these goals.

Current status of liver transplantation

Liver transplantation is accepted therapy for acute or chronic liver failure. Survival after LT has improved significantly in developed countries and this has increased the awareness of this treatment modality in the developing world. Successful LT in both children and adults have now been reported from India. Chronic liver failure secondary to cholestatic liver disease in the most frequent indication for LT, with biliary with atresia as the single commonest cause. Innovative techniques such as reduced size, splint, and living donor liver transplantation are being applied more often to decrease long waiting times and reduce associated morbidity and mortality. Early postoperative complications include primary graft failure, venous thrombosis, rejection, biliary complications and infections. Late complication includes CMV or EBV infections, side effects of immunosuppression, post transplantation lymphoproliferative disease and late biliary strictures. Most children achieve good quality of life. There are still many lessons to learn and there are future challenges such as the ever increasing problems of donor scarcity and the search for potent but less toxic immunosuppressive agents.

Strategies for optimizing immunosuppression in adolescent transplant recipients: a focus on liver transplantation

Adolescence is a difficult time for transplant recipients; they must learn to take responsibility for their own behavior and medication, and to balance their developing sexuality in a body that has been transformed by the adverse effects of immunosuppression. More than 80% of children survive transplantation to adolescence and adulthood, thus long-term outcome and tailoring of immunosuppression is of great importance. To date, the most experience with long-term immunosuppression regimens is cyclosporine, which is well tolerated and effective. Long-term adverse effects include hypertension, nephrotoxicity, and post-transplant lymphoproliferative disease (PTLD). The recent development of tacrolimus has improved the cosmetic adverse effects related to cyclosporine, but has similar rates of hypertension and nephrotoxicity, and possibly a higher rate of PTLD. There has been a recent, welcome development in renal sparing drugs, such as mycophenolate mofetil, which has no cosmetic adverse effects, does not require drug level monitoring and is thus particularly attractive to teenagers. Recent surveys demonstrate recovery of renal function with mycophenolate mofetil, if started prior to irreversible renal dysfunction. There are currently little published data on the use of sirolimus (rapamycin) in the pediatric population, but preliminary studies suggest that the future use of interleukin-2 receptor antibodies may be beneficial for immediate post-transplant induction of immunosuppression. It is important when planning immunosuppression for adolescents to consider the effects of drug therapy on both males and females in order to maintain fertility and to ensure safety in pregnancy. Noncompliance is a problem in this age group, but adequate practical measures and support should reduce noncompliance, and allow good, long-term graft function.

Use of basiliximab in pediatric liver transplantation for Langerhans cell histiocytosis

This report describes a 16-month-old girl with multi-system Langerhans cell histiocytosis (LCH), who developed end-stage liver disease despite intensive chemotherapy. She underwent a liver transplant at 28 months of age while receiving maintenance chemotherapy for bony lesions. In view of previous reports of a high incidence of acute cellular rejection and post-transplant lymphoproliferative disease (PTLD) in children transplanted for LCH, basiliximab was added to the post-transplant immunosuppression regime of tacrolimus and prednisolone. Sixteen months post-transplant, she has had no episodes of acute rejection or PTLD and her LCH has remained in remission. Current literature regarding liver transplantation (LTx) for LCH and the use of basiliximab in pediatric LTx is reviewed.

Basiliximab (Simulect) for the treatment of steroid-resistant rejection in pediatric liver transpland recipients: a preliminary experience

BACKGROUND

The role of interleukin-2 receptor antibodies as rescue therapy in steroid-resistant rejection (SRR) has not been studied. We evaluated the safety and efficacy of an interleukin-2 receptor antibody, basiliximab (Simulect, Novartis, East Hanover, NJ), in treating SRR in pediatric liver transplant recipients.

METHODS

This was a prospective study of seven pediatric liver transplant recipients with biopsy-proven SRR who would have otherwise received OKT3 or antithymocyte globulin. The primary immunosuppression consisted of cyclosporine (Neoral, Novartis), azathioprine, and prednisolone in four patients and tacrolimus and prednisolone in three patients who had undergone retransplantation for chronic rejection (n=2) and hyperacute rejection (n=1). Four patients had received two cycles of high-dose steroids, and three patients had received a single cycle; all had been converted to tacrolimus, followed by the addition of mycophenolate mofetil.

RESULTS

The median time from transplant to SRR was 30 days (range, 8 days-23 months). Five children received two doses of basiliximab (10 mg, 3-7 days apart), and two children received a single dose. Aspartate aminotransferase levels normalized in three children 12, 21, and 30 days after basiliximab treatment. Aspartate aminotransferase levels decreased without normalizing in two children, but there was no further evidence of cellular rejection on repeat biopsies. All five children are rejection-free with a median follow-up of 22 months (range, 5-32 months). Biochemical abnormalities persisted in the remaining two children, and both developed chronic rejection. There were no immediate side effects associated with basiliximab. Two patients were treated empirically for possible cytomegalovirus infection 21 and 57 days after basiliximab treatment, with no evidence of cytomegalovirus disease.

CONCLUSION

Five of seven pediatric liver transplant recipients with SRR experienced successful outcomes with basiliximab treatment without major side effects, indicating that it is a safe alternative to OKT3 and other antilymphocyte antibodies.

Long-term survival and late graft loss in pediatric liver transplant recipients--a 15-year single-center experience

Increasing numbers of children undergo successful liver transplantation. Limited data exist on long-term survival and late graft loss. Survival and graft loss were studied in 376 primary liver graft recipients who survived more than 3 months after transplantation (80.5% of all primary graft recipients). Patient records were reviewed retrospectively for causes of graft loss. Risk factors were identified by analyzing graft, recipient, and posttransplant variables using multivariate Cox regression. One-, 5-, and 10-year actuarial graft survival rates in the study population were 94.6%, 87.3%, and 86.3%, respectively. Corresponding patient survival rates were 95.7%, 91.4%, and 90.4%. Forty-seven (12.5%) grafts were lost subsequently, 15 by patient death with preserved graft function. Survival rate after late retransplantation was 63.3%. Causes of late graft loss were infection (21.2%), posttransplant lymphoproliferative disease (PTLD, 21.2%), chronic rejection (17%), biliary complications (14.8%), and recurrence of malignant disease (8.5%). Independent risk factors for late graft loss and patient death included liver malignancy as primary disease, steroid resistant rejection, and PTLD. Graft loss rate was significantly increased for reduced-size grafts. Patients undergoing transplantation after 1991 and recipients of full-size grafts were more likely to survive. In conclusion, the long-term outcome for pediatric primary liver graft recipients surviving the early postoperative period is excellent except for patients with liver malignancy. There is no increased risk of late graft loss with the use of split or living related donor grafts. Technical complications are only a minor factor in late graft loss, but complications related to immunosuppression and infection remain a major hazard and must be addressed.