Evolutionary experience with immunosuppression in pediatric intestinal transplantation

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.

Severe Late-Onset Acute Cellular Rejection in a Pediatric Patient With Isolated Small Intestinal Transplant Rescued With Aggressive Immunosuppressive Approach: A Case Report

Small intestinal transplantation is performed for patients with intestinal failure who failed other surgical and medical treatment. It carries notable risks, including, but not limited to, acute and chronic cellular rejection and graft malfunction. Late severe acute intestinal allograft rejection is associated with increased risk of morbidity and mortality and, in the majority of cases, ends with total enterectomy. It usually results from subtherapeutic immunosuppression or nonadherence to medical treatment. We present the case of a 20-year-old patient who underwent isolated small bowel transplant for total intestinal Hirschsprung disease at age 7. Due to medication nonadherence, she developed severe late-onset acute cellular rejection manifested by high, bloody ostomy output and weight loss. Ileoscopy showed complete loss of normal intestinal anatomic landmarks and ulcerated mucosa. Graft biopsies showed ulceration and granulation tissue with severe architectural distortion consistent with severe intestinal graft rejection. She initially received intravenous corticosteroids and increased tacrolimus dose without significant improvement. Her immunosuppression was escalated to include infliximab and finally antithymocyte globulin. Graft enterectomy was considered repeatedly; however, clinical improvement was noted eventually with evidence of histologic improvement and salvage of the graft. The aggressive antirejection treatment was complicated by development of post-transplant lymphoproliferative disorder that resolved with reducing immunosuppression. Her graft function is currently maintained on tacrolimus, oral prednisone, and a periodic infliximab infusion. We conclude that a prompt and aggressive immunosuppressive approach significantly increases the chance of rescuing small bowel transplant rejection.

Post-intestine transplant graft-vs-host disease associated with inclusion of a liver graft and with a high mortality risk

INTRODUCTION

This study reports the incidence, anatomic location, and outcomes of graft-vs-host disease (GVHD) at a single active intestine transplant center.

METHODS

Records were reviewed for all patients receiving an intestine transplant from 2003 to 2015. Pathology reports and pharmacy records were reviewed to establish the diagnosis, location, and therapeutic interventions for GVHD.

RESULTS

A total of 236 intestine transplants were performed during the study period, with 37 patients (16%) developing GVHD. The median time to onset of disease was 83 days, with 89% of affected patients diagnosed in the first year post-transplant. Mortality for affected patients was 54% in the 1 year after GVHD diagnosis. Skin lesions were the most common manifestation of GVHD. Other sites of disease included lungs, bone marrow, oral mucosa, large intestine, and brain. The incidence of GVHD was 16% in adult patients, and slightly lower in pediatric recipients (13%). In adults, increasing graft volume (isolated vs multi-organ) and liver inclusion were associated with increasing risk of GVHD, though this was not seen in pediatric patients.

CONCLUSION

Overall, 16% of intestine transplant recipients developed GVHD. GVHD is associated with high mortality, and disease in the lungs, brain, and bone marrow was universally fatal.

Graft-versus-host disease in paediatric solid organ transplantation: A review of the literature

GvHD is a rare and serious complication of organ transplantation. The literature is sparse following solid organ transplantation. The aim of this report was to review the literature of GvHD in paediatric solid organ transplantation. We searched PubMed for English-language full-text manuscripts between 1990 and 2015 for eligible studies. A total of 28 publications were found pertaining to paediatric GvHD following solid organ transplantation. GvHD had a mean incidence of 11% (range 8.3-13.4%) following SBTx and 1.5% following liver transplantation. Where described, the most common sites for presentation of GvHD were the skin (87%), the native GI tract (43%), the lungs (7%), the eyes (4%), HA (4%), and the kidneys (1%). Diagnosis was confirmed with biopsy (93%) and/or chimerism (41%). Treatments used include steroids (80%), of which 75% showed partial or complete resolution. Mortality was 33.3% (range 0-100%). Novel therapies include ECP and MSC therapy. GvHD is a rare but serious disease with high mortality. Novel therapies may offer hope in the future, but currently there is limited evidence for their efficacy in the context of intestinal or liver transplantation.

Intestinal and multivisceral retransplantation results: literature review

BACKGROUND

Intestinal/multivisceral transplantation (IT/MVT) is the gold standard treatment for patients with intestinal failure and complications related to total parenteral nutrition, gastrointestinal inoperable indolent tumors, or diffuse portal trombosis. Currently, the reported 1-year patient survival rate is around 80%, similar to other solid organ abdominal transplantations. Unfortunately, the patient survival decreases after the first year with the 5-year rate not close to 70% yet. Acute cellular rejection is the main cause of graft loss. Its early diagnosis may make it possible to improve survival of retransplantations.

OBJECTIVE

To analyze the reported results published in the last 5 years by leading transplant centers to evaluate IT/MVT retransplantation results.

METHODS

We performed a literature review using PubMed focusing on multivisceral and intestinal retransplantation in articles published between 2006 and 2012. In relation to the first transplantation, we analyzed demographics, imunosuppression, rejection, infection as well as graft and patient survival rates.

RESULTS

Two centers reported results on intestinal and multivisceral retransplantations. Mazariegos et al reported their experience with 15 intestinal retransplantations in 14 pediatric recipients. Four patients died from posttransplant lymphoperliferative disease, severe acute cellular rejection, fungal sepsis, or bleeding from a pseudoaneurysm at a mean time of 5.7 months post-transplantation. Total parenteral nutrition was weaned at a median time of 32 days. Abu-Elmaged et al reported 47 cases with a 5-year survival of 47% for all retransplant modalities. Retransplantation with liver-contained visceral allograft achieved a 5-year survival rate of 61% compared with 16% for liver-free visceral grafts.

CONCLUSION

Despite those huge improvements, some transplanted patients develop severe acute cellular rejection, culminating in graft loss and retransplantation. Repots on multivisceral and intestinal retransplantation outcomes suggest that it is a viable procedure with appropriate patient survival after primary graft loss.

Cutaneous graft versus host disease in pediatric multivisceral transplantation

Multivisceral transplantation (MvTx) is the concurrent transplantation of the stomach, pancreaticoduodenal complex, and intestine, with or without the liver. Its use is increasing worldwide as it has been considered as a therapy for patients with functional disturbance of several organs. Graft-versus-host disease (GvHD) has been a relevant clinical problem in MvTx ever since the procedure was first performed, but little has been reported about its specific cutaneous features. Our study included all pediatric patients with clinical and histopathologic evidence of cutaneous GvHD who received MvTx between October 1999 and December 2010 in University Hospital La Paz. Seventeen children underwent MvTx at our center during this period of time. Five patients developed cutaneous GvHD (29.4%). The median onset was 45.2 days after transplantation. Acute cutaneous GvHD, consisting of symmetrical maculopapular exanthema with prominent acral erythema and accentuated lesions on the face and pinnae, was clinically suspected and pathologically confirmed in four patients (80%). Three children (60%) experienced disease progression to a formation and a positive Nikolsky sign. Only one girl (20%) showed lichenoid GvHD. The first therapeutic approach was steroids and tacrolimus adjustment; many other drugs were used in refractory cases. Three of the five patients (60%) died with concomitant GvHD, the immediate cause of death being another comorbid disease. Knowledge of the features of cutaneous GvHD in MvTx allows clinicians early recognition and prompt therapeutic intervention that may prevent progression to higher-grade disease and improve outcomes for these patients.

Intestinal and multivisceral transplantation in patients with chronic intestinal failure

BACKGROUND

Patients with chronic intestinal failure are treated primarily with parenteral nutrition, often for many years. If serious complications arise for intravenous nutritional therapy, it is possible to perform intestinal or multi-organ transplantation in selected patients. We have established a collaboration with Professor Michael Olausson at Sahlgrenska University Hospital in Gothenburg and Professor Andreas Tzakis at the Jackson Memorial Hospital in Miami, USA, to provide an option for Norwegian patients with chronic intestinal failure.

MATERIAL AND METHOD

Retrospective long-term study of seven patients (five in Gothenburg and two in Miami) with chronic intestinal failure who underwent intestinal or multi-organ transplantation (ventricle, duodenum, pancreas and small intestine) in the period 2001-2009. At the same time, liver and kidney transplantations were performed on six and two patients, respectively.

RESULTS

Four of seven patients are alive and have a good quality of life 24-120 months after the transplantation. The graft function is satisfactory, so that the patients' food intake is mainly oral. Three patients died following a serious infection one, ten and 24 months, respectively, after transplantation took place.

INTERPRETATION

Intestinal and multi-organ transplantation is a demanding and expensive treatment. Life-long multi-disciplinary follow-up of the patients is necessary after the transplantation in order to ensure early diagnosis of rejection and infections. Collaboration with international centres has given Norwegian patients with chronic intestinal failure an option of transplantation with satisfactory long-term results.

Intestinal transplantation in children: a review of immunotherapy regimens

This review summarizes the outcomes and known adverse effects of current immunosuppression strategies in use in pediatric intestinal transplantation. Intestinal transplantation has evolved from an experimental therapy to a highly successful treatment for children with intestinal failure who have complications with total parenteral nutrition. Because of continued success with intestinal transplantation over the past decade, the focus of clinicians and researchers is shifting from short-term patient survival to optimizing long-term outcomes. Current 5-year patient and graft survival rates after intestinal transplantation are 58% and 40%, respectively, in the US; single centers have reported nearly 80% patient and 60% graft survival rates at 5 years. The immunosuppression strategy in intestinal transplantation includes a tacrolimus-based regimen, usually in conjunction with an antibody induction therapy such as rabbit-antithymocyte globulin, interleukin-2 receptor antagonists, or alemtuzumab. The use of these immunosuppressive regimens, along with improved medical and surgical care, has contributed significantly toward improved outcomes. Optimization of post-transplant immunosuppression strategies to reduce adverse effects while minimizing acute and chronic graft rejection is a strong clinical and research focus.

Posttransplant lymphoproliferative diseases

The risk of developing cancer after solid organ transplantation (SOT) is about 5- to 10-fold greater than that of the general population. The cumulative risk of cancer rises to more than 50% at 20 years after transplant and increases with age, and so children receiving transplants are at high risk of developing a malignancy. Posttransplant lymphoproliferative disease (PTLD) is the most common cancer observed in children following SOT, accounting for half of all such malignancies. PTLD is a heterogeneous group of disorders with a wide spectrum of pathologic and clinical manifestations and is a major contributor to long-term morbidity and mortality in this population. Among children, most cases are associated with Epstein-Barr virus infection. This article reviews the pathology, immunobiology, epidemiology, and clinical aspects of PTLD, underscoring the need for ongoing systematic study of complex biologic and therapeutic questions.

Current perspectives on pediatric intestinal transplantation

Irreversible intestinal failure in children is predominantly caused by surgical conditions such as volvulus, necrotizing enterocolitis, and gastroschisis. Functional intestinal failure from motility disorders such as intestinal pseudo-obstruction or enterocyte dysfunction with microvillus inclusion disease also may require intestine replacement. Approved indications for intestinal transplantation include liver dysfunction, loss of major venous access, frequent central line-related sepsis, and recurrent episodes of severe dehydration despite intravenous fluid management. Surgical options include transplantation of the isolated intestine, combined liver-intestine transplantation, or multivisceral transplantation of the stomach, duodenum, pancreas, and small bowel (with or without the liver). Immunosuppression for intestinal transplantation is based on tacrolimus therapy, often with induction immunosuppression using antilymphocyte antibodies (eg, antithymocyte antibody and alemtuzumab). Experience at centers of excellence demonstrates 1- and 5-year patient survival rates of 95% and 77%, respectively, with ongoing investigations focusing on lowering long-term causes of graft loss such as chronic rejection.

Rotavirus infection in small bowel transplant: a histologic comparison with acute cellular rejection

Pediatric small bowel transplant recipients are susceptible to diarrhea due to rejection or infectious enteritis, particularly of viral etiology. The most common causes of viral enteritis in this setting are rotavirus, adenovirus, cytomegalovirus, and Epstein-Barr virus. This study is the first to compare the histologic findings of rotavirus infection with acute cellular rejection in small bowel transplant biopsies. Three patients with small bowel transplants had rapid stool antigen test-proven rotavirus infection. Endoscopic biopsies during infection were examined, including material from the allograft, native small bowel, stomach, and colon. Biopsies from 2 of the patients during unrelated episodes of mild acute cellular rejection were also evaluated. Blunting of villi was the most common finding in rotavirus infection. Additionally, there was a mononuclear infiltrate that was "top heavy," or denser towards the lumen. There were surface apoptoses but no increase in crypt apoptotic figures. In contrast, during mild acute cellular rejection, there was no villous blunting, the mononuclear infiltrate was diffuse, and there were increased crypt apoptosis. As expected, the changes of acute cellular rejection were confined to the graft, in contrast to rotavirus infection, in which case native bowel often had more pronounced changes. Although the small number of patients limits this study, several histologic features were helpful in identifying rotavirus infection. These were blunting of villi, distribution of the inflammatory infiltrate, number and location of apoptotic bodies, and anatomic location of the effect. A larger follow-up study would be valuable to confirm these findings.

Current status of small bowel and multivisceral transplantation

Intestinal transplantation has shown exceptional growth over the past 20 years with remarkable progress. As with other solid organ transplants, intestinal transplantation has moved out of the experimental realm to become the stan dard of care for many patients with intestinal failure. Intestinal transplantation may soon be extended routinely to patients who, although not strictly meeting the criteria for intestinal failure, may benefit from intestinal transplantation, such as patients who have nonresectable indolent tumors or diffuse thrombosis of the portomesenteric system. As clinical experience has increased with intestinal transplantation, outcomes have improved. The currently reported 1-year graft and patient survival rate is 80%, which approaches that for other solid abdominal organs. Unfortunately, most of the gains in survival are seen in the first postoperative year, with long-term survival remaining basically unchanged since the early 1990s. With improved outcomes, more centers have entered into the intestinal transplant arena. In the United States alone, 20 centers performed at least one intestinal transplant in 2007. Increase in access to intestinal transplantation and more widespread awareness of this option likely will result in a consistent increase in the number of yearly transplants for the foreseeable future. Immunosuppressive regimens continue to evolve, with induction therapy being the major change in the past 5 years. Although rejection rates in the first year after transplant have been reduced by induction therapy, long-term side effects of heavy immunosuppression continue to weigh negatively on transplant outcomes. The future for immunosuppression lies in two areas: (1) individual monitoring of the immunosuppression level for each individual patient and (2) development of serum and tissue markers for the early identification of rejection. It is likely that a combination of technologies will allow immunosuppression to be tailored to each recipient. Development of these approaches to immunosuppression is necessary to predict graft dysfunction ahead of irreversible graft injury and allows adjustments in immunosuppression before the onset of rejection. Intestinal transplantation continues to be performed only in situations in which all other therapeutic modalities have failed. No randomized trials compare intestinal transplantation to long-term PN to establish guidelines for a timely referral for this treatment option. Late referral remains a crippling problem in the field of intestinal transplantation, with a great number of patients in need of simultaneous liver transplantation at the time of listing for intestinal transplantation. Early referral for isolated intestinal transplant will reduce the need for simultaneous multiorgan transplants and increase the residual organs available for patients in need of (primarily) liver transplantation.

Chronic rejection after combined liver and small bowel transplantation in a child with chronic intestinal pseudo-obstruction: a case report

An 11-year-old boy with irreversible intestinal failure secondary to chronic intestinal pseudo-obstruction (CIPO) and intestinal failure-associated liver disease (IFALD) underwent a combined en bloc reduced liver and small bowel transplantation. He was discharged home after 9 weeks on full oral intake without requiring intravenous nutritional or fluid supplementation. The first episode of mild acute rejection, which occurred 18 months after transplantation, was successfully treated with steroids. An episode of rotavirus gastroenteritis led to severe exfoliative rejection of the bowel graft, which was resistant to steroid and Infliximab treatment but responded to OKT3. There was associated Epstein-Barr virus viremia with no evidence of posttransplant lymphoproliferative disease. Another episode of moderate to severe acute liver rejection occurred 5 months later. At the same time, multiple biliary strictures were diagnosed and treated. Persistent clinical symptoms of abdominal pain and increased stomal output as well as atrophy of the ileal mucosa on several biopsies, suggested the possibility of chronic rejection (CR). A second combined whole liver and small bowel transplant was performed. The diagnosis of CR was confirmed on histology of the explanted graft. The postoperative course was severely complicated and 71 days after the retransplantation, the boy died because of respiratory failure and multiorgan failure. In summary, intestinal transplantation can be successfully performed in children with CIPO, giving them the opportunity to be free from total parenteral nutrition. As survival following intestinal transplantation continues to improve, the problem of CR has become increasingly important and the only treatment available is retransplantation, which is associated with poor outcomes.

Pediatric intestinal and multivisceral transplantation: a new challenge for the pediatric intensivist

Introduction

With increasing survival rates, intestinal transplantation (ITx) and multivisceral transplantation have reached the mainstream of medical care. Pediatric candidates for ITx often suffer from severe multisystem impairments that pose challenges to the medical team. These patients frequently require intensive care preoperatively and have unique intensive care needs postoperatively.

Methods

We reviewed the literature on intensive care of pediatric intestinal transplantation as well as our own experience. This review is not aimed only at pediatric intensivists from ITx centers; these patients frequently require ICU care at other institutions.

Results

Preoperative management focuses on optimization of organ function, minimizing ventilator-induced lung injury, preventing excessive edema yet maintaining adequate organ perfusion, preventing and controlling sepsis and bleeding from varices at enterocutaneous interfaces, and optimizing nutritional support. The goal is to extend life in stable condition to the point of transplantation. Postoperative care focuses on optimizing perfusion of the mesenteric circulation by maintaining intravascular volume, minimizing hypercoagulability, and providing adequate oxygen delivery. Careful monitoring of the stoma and its output and correction of electrolyte imbalances that may require renal replacement therapy is critical, as are monitoring for and aggressively treating infections, which often present with only subtle clinical clues. Signs of intestinal rejection may be non-specific, and early differentiation from other causes of intestinal dysfunction is important. Understanding of the expanding armamentarium of immunosuppressive agents and their side-effects is required.

Conclusions

As outcomes of ITx improve, transplant teams accept patients with higher pre-operative morbidity and at higher risk for complications. Many ITx patients would benefit from earlier referral for transplant evaluation before severe liver disease, recurrent central venous catheter-related sepsis and venous thromboses develop.

Ethics and the pediatric surgeon

PURPOSE

Care of infants and children with life-impairing or life-threatening congenital and acquired disorders often raises ethical concerns for pediatric surgeons. The purpose of this survey was to determine the level of interest in clinical ethics and how respondents would manage ethical dilemmas within several clinical case scenarios.

METHODS

A 12-item validated questionnaire developed by the Ethics and Advocacy Committee was provided for the American Pediatric Surgical Association (APSA; www.eapsa.org) members on the organizational website. General categories of questions included informed consent, patient privacy, and what constitutes research.

RESULTS

The survey was completed by 235 of the 825 APSA members; a response rate of 28.4%. The majority (62%) were in academic practice, 22% had additional education or an advanced degree in ethics, and 11% were members of a hospital ethics committee. There was a clear majority response for seven questions. Topics generating the most controversy included the impact of consent by minors, decision making in the neurologically devastated child, what constitutes research in pediatric surgery, the use of interpreters for consent, and patient privacy. Respondents chose a well-referenced manuscript as the preferred modality for ethics education of the APSA members.

CONCLUSION

Pediatric surgeons have a general interest in clinical ethics as it relates to the care of their patients. An important mission of the Ethics and Advocacy Committee can be to provide education that gives guidance and knowledge to the members of APSA on timely topics in surgical ethics.

Network approach to the child with primary intestinal failure

Intestinal failure (IF) is a rare condition resulting from short gut and other heterogeneous intestinal diseases. Major centers in Italy merged in a national network to build common diagnostic and management approaches and to investigate the natural history of IF. Gastroenterological reference centers with specific expertise in intestinal morphology, diagnosis of autoimmune conditions, intestinal microbiology and parenteral nutrition were identified to act as consultants to the network. These centers of expertise provided specific diagnostic approaches while ensuring high technical standards. The approach allowed each center to learn from a larger cohort of patient samples. A database was set up to investigate etiology, epidemiology and natural history of IF. A common diagnostic algorithm for intractable diarrhea was designed. This process was largely based on electronic communication among centers and specimen shipping. Etiologic diagnosis was obtained in almost all cases of IF secondary to severe protracted diarrhea. The study of the natural history of IF showed a close association between etiology of IF and its outcome. The natural history of IF also provided the starting point for specific therapeutic approaches to its complications such as parenteral nutrition-associated cholestasis and catheter-related sepsis. The network approach to IF provides an effective model to optimize resources and prospectively investigate the natural history of IF, essential steps to design interventions, including intestinal transplantation and improve the outcome of IF.

Mechanical Extension Implants for Short-Bowel Syndrome

Short-bowel syndrome (SBS) is a rare, potentially lethal medical condition where the small intestine is far shorter than required for proper nutrient absorption. Current treatment, including nutritional, hormone-based, and surgical modification, have limited success resulting in 30% to 50% mortality rates. Recent advances in mechanotransduction, stressing the bowel to induce growth, show great promise; but for successful clinical use, more sophisticated devices that can be implanted are required. This paper presents two novel devices that are capable of the long-term gentle stressing. A prototype of each device was designed to fit inside a short section of bowel and slowly extend, allowing the bowel section to grow approximately double its initial length. The first device achieves this through a dual concentric hydraulic piston that generated almost 2-fold growth of a pig small intestine. For a fully implantable extender, a second device was developed based upon a shape memory alloy actuated linear ratchet. The proof-of-concept prototype demonstrated significant force generation and almost double extension when tested on the benchtop and inside an ex-vivo section of pig bowel. This work provides the first steps in the development of an implantable extender for treatment of SBS.

The Bianchi procedure: a 20-year single institution experience

BACKGROUND/PURPOSE

The emergence of improved outcomes for small bowel (SB) transplantation has raised questions regarding the utility of autologous intestinal lengthening for patients with short bowel syndrome (SBS). Chronic immunosuppression, multiple hospitalizations, and posttransplant lymphoproliferative disease are significant adverse factors. The purpose of this study is to evaluate the 20-year single institution experience with the Bianchi procedure and analyze its role in the management of pediatric SBS.

METHODS

Medical records for 19 consecutive patients who underwent the Bianchi procedure from 1984 to 2004 were reviewed. Patients were categorized into 3 groups: less than 5 years, 5 to 9.9 years, and 10 years or more after surgery. Various outcome variables were evaluated. Data are presented in tabular format as the number of patients (%) or average (range).

RESULTS

Nineteen patients were included in the study. Of 16 patients weaned from total parenteral nutrition (TPN), 7 (44%) responded to Bianchi procedure alone and 9 patients (56%) required SB transplant at an average of 4.09 years (range, 0.7-13.64 years) post-Bianchi. Four patients (21%) died, 1 received SB transplant and died of unrelated causes, and 3 were still on TPN and had not received SB transplantation.

CONCLUSION

The Bianchi procedure facilitated weaning from TPN and eliminated the need for supplemental nutrition in select patients. Although the role of surgery is primarily adjunctive in the treatment of SBS, it offers therapeutic benefit in decreasing parenteral nutrition requirements and promoting intestinal adaptation. In particular, the Bianchi procedure has significant potential to improve the prognosis of pediatric patients with SBS.