The use of anti-interleukin-2 receptor antibodies in pediatric liver transplantation

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.

Obesidade e adipocinas inflamatórias: implicações práticas para a prescrição de exercício

A obesidade é uma doença complexa de etiologia multifacetada, com sua própria fisiopatologia, comorbidades e capacidades desabilitantes. Aceitar a obesidade como uma doença é fundamental para o seu tratamento. Atualmente, o tecido adiposo é um dos principais focos das pesquisas em obesidade, devido a uma revolução no entendimento da função biológica desse tecido desde a última década. Já está muito claro que o tecido adiposo branco secreta múltiplos peptídeos bioativos, denominados adipocinas (proteínas sintetizadas e secretadas pelo tecido adiposo). Dessa forma, o objetivo deste trabalho de revisão foi investigar a relação entre obesidade e adipocinas inflamatórias, buscando discutir o papel do exercício físico no tratamento dessa patologia. Os resultados demonstram que uma das mais importantes descobertas das pesquisas recentes em obesidade é o conceito de que ela é caracterizada por uma inflamação crônica. Dentre todas as adipocinas, sem dúvida, a IL-6, o TNF-α, a leptina (pró-inflamatórias) e a adiponectina (anti-inflamatória) vêm recebendo atenção especial da literatura especializada. O aumento da concentração dessas adipocinas promove grande impacto em diversas funções corporais que estão fortemente correlacionadas com doenças cardiovasculares. Uma vez que a obesidade é considerada uma doença inflamatória e o exercício físico modula de forma direta tais processos, é essencial que tenhamos como um dos objetivos principais de nossos programas de exercícios físicos a melhora da resposta inflamatória de obesos.

Calcineurin inhibitor minimization in pediatric liver allograft recipients

The use of CNI in pediatric LTx has dramatically improved the outcome for children with end-stage liver disease by significantly reducing the rate of acute and chronic rejection. Long-term concerns about CNI-induced nephrotoxicity and other adverse effects remain an issue, particularly as the emphasis moves from short-term survival to long-term quality of life. This review summarizes lessons learnt from pediatric and adult solid organ transplantation in minimizing CNI use in immunosuppression protocols in children following LTx. There are three models for CNI minimization: dose reduction, withdrawal or avoidance, supplemented by the use of IL-2 receptor blocking antibodies in the peri-transplant period, and early transition to alternate drugs such as MMF or SRL. Prospective studies evaluating reduction or withdrawal protocols in adult and pediatric LTx indicate that rejection rates are comparable with traditional CNI-based immunosuppression and that two and five yr patient and graft survival are similar, with recovery in renal function. There are few studies evaluating complete avoidance of CNI, apart from that in renal transplantation, although the benefits of long-term reduction in cardiovascular, metabolic, and possibly neoplastic side effects may justify this approach. It is not clear yet how CNI minimization will affect the development of tolerance but experimental and preliminary clinical studies indicate that CNI and steroid avoidance or minimization in the peri-operative period may favor the development of long-term graft tolerance. In summary, CNI minimization may be safe and effective in the short term but large-scale pediatric randomized studies are required to evaluate the long-term efficacy of these regimes in the development of chronic rejection, PTLD, and graft tolerance.

Steroid-free, tacrolimus-basiliximab immunosuppression in pediatric liver transplantation: clinical and pharmacoeconomic study in 50 children

Corticosteroid-free immunosuppression (IS) may be potentially beneficial for transplanted patients, particularly children. The purpose of this study was to evaluate the efficacy and cost of such strategy in primary pediatric liver transplantation (LT). Fifty pediatric LT recipients were prospectively treated with a steroid-free, tacrolimus-basiliximab-based IS (group TB). A group of 34 children transplanted under a conventional tacrolimus-steroids regimen served as control series (group TS). Groups TB and TS were compared regarding patient and graft survival, rejection incidence, infectious complications, and growth, as well as cost of the transplant procedure. Patient and graft survivals at 3 years were 96% and 94% in group TB, versus 91% and 88% in group TS (P = 0.380 and P = 0.370, respectively). Rejection-free graft survival at 3 years was 72% in group TB, versus 41% in group TS (P = 0.007). Patients in group TB had significantly less viral infections than patients in group TS (P = 0.045). Height standard deviation score was significantly enhanced in children from group TB, when compared to group TS. Medical care costs were similar in both groups. Steroid avoidance together with basiliximab immunoprophylaxis was not harmful in terms of allograft acceptance, and even seemed to be beneficial in the long term.

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.

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.

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.

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.