Pediatric small bowel transplantation

The Outcomes of Treatment in Infants with Short Bowel Syndrome

Objective We reviewed 50 infant cases with short bowel syndrome (SBS) to examine the treatment outcome of SBS management in a tertiary hospital in Vietnam.

Material and Methods A case series was performed at the National Children's Hospital, Hanoi, Vietnam. A total of 50 cases with SBS were reviewed. Clinical and laboratory characteristics before and after treatment were collected.

Results The most common cause of SBS was necrotizing enterocolitis. Common clinical symptoms included watery stools, dehydration, and malnutrition. After treatment, the patient's weight, albumin, and prothrombin improved markedly. There are 72% of children with good or fair treatment results. The rate of sepsis was high (18%). There was one case with complications of catheter infection and one case of liver failure. Three children died during treatment, one died from septic shock and multiple organ failure, and two died from respiratory failure.

Conclusion This study showed promising treatment outcomes in pediatrics.

Operational tolerance after intestine re-transplantation in childhood and immunological correlates. Case report and review

BACKGROUND

Operational tolerance after retransplantation of the intestine has never been reported.

PURPOSE

To two recently described intestine transplant recipients with operational tolerance, we now add a third.

METHODS

Review of case record and immunological testing to confirm donor-specific hyporesponsiveness in multiple immune cell compartments.

RESULTS

Re-transplanted with a multivisceral liver- and kidney-inclusive intestine allograft at age 12 years, this recipient self-discontinued immunosuppression 14 years after the retransplant and has been rejection free for 2 years thereafter. As in the two previous reports, immunological testing demonstrated decreased donor-specific inflammatory response of T-cytotoxic memory cells and B-cells, decreased presentation of donor antigen by B-cells and monocytes, absence of donor-specific anti-HLA antibodies, circulating FOXP3 + T-helper cells, and intact cellular and humoral immunity to cytomegalovirus and Epstein-Barr virus. Additionally, our recipient demonstrated enhanced donor-activation-induced apoptosis of alloreactive T-cytotoxic memory cells.

CONCLUSIONS

Despite variable paths to tolerance which include graft versus host disease in two previous cases, and rejection-related loss of the primary isolated intestinal allograft in our recipient, the three cases with operational tolerance are bound by common themes: a relatively large donor antigenic load transmitted during intestine transplantation, and donor-specific hyporesponsiveness. Cell-based assays suggest enhanced donor-induced apoptosis of recipient T-cells and circulating T-regulatory cells as mechanistic links between antigenic load and donor-specific hyporesponsiveness.

Endoscopic ultrasound in the monitoring of the intestinal allograft

Objective

Chronic rejection (CR) of the small intestinal allograft includes mucosal fibrosis, bowel thickening and arteriopathy in the outer wall layers and the mesentery. CR lacks non-invasive markers and reliable diagnostic methods. We evaluated endoscopic ultrasound (EUS) as a novel approach for monitoring of the intestinal allograft with respect to CR.

Design

In intestinal graft recipients, EUS and enteroscopy with ileal mucosal biopsy were performed via the ileostomy. At EUS, the wall thickness of the intestinal graft was measured in standard mode, whereas the resistive index (RI) of the supplying artery was assessed in pulsed Doppler mode. At enteroscopy, the intestinal mucosa was assessed. Findings were compared with histopathology and clinical follow-up.

Results

EUS was successfully performed in all 11 patients (adequate clinical course (AC) n=9; CR n=2) after a median interval of 1537 days (range: 170–5204), post-transplantation. The total diameter of the wall (layer I–V) was comparable in all patients. Meanwhile, the diameter of the outermost part (layer IV–V; that is, muscularis propria–serosa) was among the two CR patients (range: 1.3–1.4 mm) in the upper end of measurements as compared with the nine AC patients (range: 0.5–1.4 mm). The RI was >0.9 in both CR patients, while the RI was ≤0.8 in all AC patients. Both CR patients had abnormal findings at enteroscopy and histopathology and deceased during follow-up.

Conclusion

EUS is a promising tool providing detailed information on the intestinal graft morphology and rheology, which may be used for assessment of potential CR in long-term follow-up of intestinal allograft recipients.

Differential cytokine and chemokine expression during rejection and infection following intestinal transplantation

BACKGROUND/OBJECTIVES

Rejection and infectious enteritis in intestinal transplant (ITx) patients present with virtually identical symptoms. Currently, the gold standard for differentiating between these two conditions is endoscopy, which is invasive and costly. Our primary aim was to identify differences in peripheral blood cytokines during episodes of acute cellular rejection (ACR) and infectious enteritis in patients with intestinal transplants.

METHODS

This was a prospective, cross-sectional study involving ITx patients transplanted between 2000 and 2016. We studied 63 blood samples collected from 29 ITx patients during periods of normal (n = 24) and abnormal (n = 17) allograft function. PBMCs from whole blood samples were cultured under unstimulated or stimulated conditions with phytohemagglutinin (PHA). The supernatant from these cultures were collected to measure cytokine and chemokine levels using a 38-plex luminex panel.

RESULTS

Our study found that cytokines and chemokines are differentially expressed in normal, ACR, and infectious enteritis samples under unstimulated conditions based on heatmap analysis. Although each cohort displayed distinctive signatures, only MDC (p = 0.037) was found to be significantly different between ACR and infectious enteritis. Upon stimulation of PBMCs, patients with ACR demonstrated increased immune reactivity compared to infectious enteritis; though this did not reach statistical significance.

CONCLUSIONS

To our knowledge, this is the first comprehensive study comparing cytokine expression during acute rejection and infectious enteritis in intestinal transplant recipients. Our results suggest that cytokines have the potential to be used as clinical markers for risk stratification and/or diagnosis of ACR and infectious enteritis.

Mesenchymal Stromal Cell Therapy in Solid Organ Transplantation

Transplantation is the gold-standard treatment for the failure of several solid organs, including the kidneys, liver, heart, lung and small bowel. The use of tailored immunosuppressive agents has improved graft and patient survival remarkably in early post-transplant stages, but long-term outcomes are frequently unsatisfactory due to the development of chronic graft rejection, which ultimately leads to transplant failure. Moreover, prolonged immunosuppression entails severe side effects that severely impact patient survival and quality of life. The achievement of tolerance, i.e., stable graft function without the need for immunosuppression, is considered the Holy Grail of the field of solid organ transplantation. However, spontaneous tolerance in solid allograft recipients is a rare and unpredictable event. Several strategies that include peri-transplant administration of non-hematopoietic immunomodulatory cells can safely and effectively induce tolerance in pre-clinical models of solid organ transplantation. Mesenchymal stromal cells (MSC), non-hematopoietic cells that can be obtained from several adult and fetal tissues, are among the most promising candidates. In this review, we will focus on current pre-clinical evidence of the immunomodulatory effect of MSC in solid organ transplantation, and discuss the available evidence of their safety and efficacy in clinical trials.

Induction regimens and post-transplantation lymphoproliferative disorder after pediatric intestinal transplantation: Single-center experience

Pediatric recipients of intestinal transplants have a high incidence of PTLD, but the impact of specific induction immunosuppression agents is unclear. In this single-center retrospective review from 2000 to 2017, we describe the incidence, characteristics, and outcomes of PTLD after primary intestinal transplantation in 173 children with or without liver, after induction with rATG, alemtuzumab, or anti-IL-2R agents. Thirty cases of PTLD occurred among 28 children, 28 EBV+ and 2 EBV-. Although not statistically significant, the PTLD incidence was higher after isolated intestinal transplant compared with liver-inclusive allograft (19.3% vs 13.3%, P = .393) and after induction with anti-IL-2R antibody and alemtuzumab compared with rATG (28.6% and 27.3% vs 13.3%, P = .076). The 30 PTLD cases included 13 monomorphic PTLD, 13 polymorphic PTLD, one spindle cell, one Burkitt lymphoma, and two cases too necrotic to classify. After reduction of immunosuppression, management was based on disease histology and extent. Resection with or without rituximab was used for polymorphic tumors and limited disease extent, whereas chemotherapy was used for diffuse disease. Of the 28 patients, 11 recovered with functioning allografts (39.3%), 10 recovered after enterectomy (35.7%), and seven patients died (25%), three due to PTLD and four due to other causes. All who died of progressive PTLD had received chemotherapy, highlighting the mortality of PTLD, toxicity of treatment and need for novel agents. Alemtuzumab is no longer used for induction at our center.

Pediatric intestinal transplantation: Analysis of the intestinal transplant registry

The ITR serves as an international database for centers around the world to contribute to current knowledge about intestinal transplant outcomes. Led by the IRTA and managed by the Terasaki Research Institute, the ITR collects data annually and uses these data to generate reports that guide management strategies and policy statements. The aim of this manuscript was to analyze outcomes specific to pediatric intestinal transplantation. Outcome data for children transplanted from 1985 to 2017 were analyzed and predictive factors assessed. A total of 2010 children received 2080 intestine containing allografts during this period. Overall, 1-year and 5-year patient and graft survival were 72.7%/66.1% and 57.2/48.8%, respectively. One-year conditional survival was most strongly associated with being a first-time transplant recipient and liver-inclusive grafts. Patient survival was most strongly associated with elective status of transplantation as compared with hospitalized status. Enteral autonomy following transplantation has continued to improve by era with colonic inclusion demonstrating additional incremental improvement in enteral autonomy and freedom from intravenous fluid. While PTLD and technical complications contribute less to graft loss than in earlier eras, rejection remains the largest contributor to long-term graft loss. Re-transplantation is linked with significantly worse conditional graft survival, and sepsis remains the largest contributor to patient death. Newer data elements are focusing on impact of donor variables, donor and recipient tissue typing, and impact of the development of de novo antibodies.

The colon as an energy salvage organ for children with short bowel syndrome

BACKGROUND

The main cause of intestinal failure is short bowel syndrome (SBS). The management goal for children with SBS is to promote intestinal adaptation while preserving growth and development with the use of parenteral nutrition (PN).

OBJECTIVES

This study evaluated the intestinal absorption rate in children with SBS, focusing on the role of the remnant colon. In addition, the relation between intestinal absorption rate, citrulline concentration, and small bowel length was studied.

METHODS

Thirty-two children with SBS on PN were included. They were divided into 3 groups according to the European Society for Clinical Nutrition and Metabolism (ESPEN) anatomical classification system: type 1 SBS (n = 9), type 2 (n = 13), and type 3 (n = 10). Intestinal absorption rate was assessed by a stool balance analysis of a 3-d collection of stools. Plasma citrulline concentrations were measured and the level of PN dependency was calculated.

RESULTS

The total energy absorption rate did not differ significantly between the 3 groups: 68% (61-79% ) for type 1, 60% (40-77%) for type 2, and 60% (40-77%) for type 3 ( P = 0.45). Children with type 2 or 3 SBS had significantly shorter small bowel length than children with type 1: 28 cm (19-36 cm) and 16 cm (2-29 cm), respectively, compared with 60 cm (45-78 cm) ( P = 0.04). Plasma citrulline concentrations were lower in type 3 SBS but not significantly different: 15 µmol/L (11-25 µmol/L) in type 1, 14 µmol/L (7-21 µmol/L) in type 2 , and 9 µmol/L (6-14 µmol/L) in type 3 ( P = 0.141). A multivariate analysis confirmed the role of the remnant colon in providing additional energy absorption.

CONCLUSION

This study demonstrated the importance of the colon as a salvage organ in children with SBS. Plasma citrulline concentrations should be interpreted according to the type of SBS. Efforts should focus on conservative surgery, early re-establishment of a colon in continuity, and preserving the intestinal microbiota.

Update on Chronic Rejection After Intestinal Transplant: An Overview From Experimental Settings to Clinical Outcomes

Chronic rejection affects the long-term survival of solid-organ transplants, accounting for an incidence of between 5% and 10% after intestinal/multivisceral transplant. Because of unclear symptoms and signs and endoscopic findings, the diagnosis is often delayed. Presently, allograft removal represents the only available therapy due to the absence of effective pharmacologic approaches. Extensive research, through animal models, has been performed over the past 20 years to clarify the complex immune- and nonimmune-mediated mechanisms behind the development of chronic allograft enteropathy, with the aim of elucidating how to avert chronic rejection. The role of donor-specific antibodies and the way to challenge them in the clinic have gained acceptance among transplant centers as one of the main steps to prevent chronic rejection, although no common protocol exists that can be applied in a systematic fashion. The adjunct of a liver graft when retrans planting is needed in a sensitized recipient due to its protective effect against humoral immunity. Multicenter studies and clinical trials are required to better understand the pathogenesis of chronic rejection and to find the therapeutic answer to this clinical query.

The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation

Despite recent advances, cytomegalovirus (CMV) infections remain one of the most common complications affecting solid organ transplant recipients, conveying higher risks of complications, graft loss, morbidity, and mortality. Research in the field and development of prior consensus guidelines supported by The Transplantation Society has allowed a more standardized approach to CMV management. An international multidisciplinary panel of experts was convened to expand and revise evidence and expert opinion-based consensus guidelines on CMV management including prevention, treatment, diagnostics, immunology, drug resistance, and pediatric issues. Highlights include advances in molecular and immunologic diagnostics, improved understanding of diagnostic thresholds, optimized methods of prevention, advances in the use of novel antiviral therapies and certain immunosuppressive agents, and more savvy approaches to treatment resistant/refractory disease. The following report summarizes the updated recommendations.

Improvements in intestine transplantation

Transplantation of the intestine in children has presented significant challenges even as it has become a standard to treat nutritional failure due to short gut syndrome. These challenges have been addressed in part by significant improvements in short and long-term care. Noteworthy enhancements include reduced need for intestine transplantation, drug-sparing immunosuppressive regimens, immune monitoring, and improved surveillance and management of PTLD and non-adherence.

Chronic Rejection After Intestinal Transplant: Where Are We in Order to Avert It?

Chronic rejection affects the long-term survival of all solid organ transplants and, among intestinal allografts, occurs in up to 10% of the recipients. The insidious clinical evolution of the chronic allograft enteropathy, the absence of noninvasive biomarkers, and the late endoscopic findings delay its diagnosis. No pharmacological approach has been proven effective, and allograft removal nowadays still represents the only available therapy. The inclusion of the liver in the visceral allograft appears to be the only intervention affecting the development of chronic rejection, as revealed by large-center studies and registry reports. A significant body of evidence emerged from the experimental setting and provided essential knowledge on the complex mechanisms behind the development of chronic allograft enteropathy. More recently, donor-specific antibodies have been suggested as an early, key element in the natural history of chronic allograft enteropathy and several novel approaches, tackling the antibody-mediated graft injury, have gained acceptance in clinical settings and are believed to impact on chronic rejection. The inclusion of a liver allograft is advocated when re-transplanting a sensitized recipient, due to its protective effect against humoral immunity. Multicenter trials are required to understand and tackle chronic rejection, and find the therapeutic answer to this clinical dilemma.

Advances in small bowel transplantation

Small bowel transplantation is a life-saving surgery for patients with intestinal failure. The biggest problem in intestinal transplantation is graft rejection. Graft rejection is the main reason for morbidity and mortality. Rejection has a negative effect on the survival of the graft. While 50%-75% of small bowel transplantation patients experience acute rejection, chronic rejection occurs in approximately 15% of patients. Immune monitoring is crucial after small bowel transplantation. Unlike other types of transplantation, there are no non-invasive or reliable markers to predict rejection in small bowel transplantation. The diagnosis of AR is confirmed by clinical symptoms, endoscopic appearance, and pathological specimens taken by endoscopy. Thus, histopathological examinations obtained by protocol biopsies remain as the gold standard for intestinal graft monitoring; however, biopsies have some complications, especially in small grafts. In addition to the high complication rate, biopsies are non-diagnostic; thus, multiple biopsies should be performed to exclude rejection. Therefore, auxiliary assays, such as measurements of citrulline and calprotectin in the blood, cytofluorographic examination of peripheral blood immune cells, cytokine profiling, and distinct gene-set-change measurements, are increasingly being used in small bowel transplantation. Developments in the understanding of genes seem to be promising that limited gene sets, taken from blood or from intestinal biopsies, will enhance pathological diagnosis. Bone marrow mesenchymal stem cell transplantation with SBT and tissue engineering are also promising procedures.

Predicting Cellular Rejection With a Cell-Based Assay: Preclinical Evaluation in Children

BACKGROUND

Allospecific CD154+T-cytotoxic memory cells (CD154+TcM) predict acute cellular rejection after liver transplantation (LTx) or intestine transplantation (ITx) in small cohorts of children and can enhance immunosuppression management, but await validation and clinical implementation.

METHODS

To establish safety and probable benefit, CD154+TcM were measured in cryopreserved samples from 214 children younger than 21 years (National Clinical Trial 1163578). Training set samples (n = 158) were tested with research-grade reagents and 122 independent validation set samples were tested with current good manufacturing practices-manufactured reagents after assay standardization and reproducibility testing. Recipient CD154+TcM induced by stimulation with donor cells were expressed as a fraction of those induced by HLA nonidentical cells in parallel cultures. The resulting immunoreactivity index (IR) if greater than 1 implies increased rejection-risk.

RESULTS

Training and validation set subjects were demographically similar. Mean coefficient of test variation was less than 10% under several conditions. Logistic regression incorporating several confounding variables identified separate pretransplant and posttransplant IR thresholds for prediction of rejection in the respective training set samples. An IR of 1.1 or greater in posttransplant training samples and IR of 1.23 or greater in pretransplant training samples predicted LTx or ITx rejection in corresponding validation set samples in the 60-day postsampling period with sensitivity, specificity, positive, and negative predictive values of 84%, 80%, 64%, and 92%, respectively (area under the receiver operator characteristic curve, 0.792), and 57%, 89%, 78%, and 74%, respectively (area under the receiver operator characteristic curve, 0.848). No adverse events were encountered due to phlebotomy.

CONCLUSIONS

Allospecific CD154+T-cytotoxic memory cells predict acute cellular rejection after LTx or ITx in children. Adjunctive use can enhance clinical outcomes.

Profile of the Pleximmune blood test for transplant rejection risk prediction

The Pleximmune™ test (Plexision Inc., Pittsburgh, PA, USA) is the first cell-based test approved by the US FDA, which predicts acute cellular rejection in children with liver- or intestine transplantation. The test addresses an unmet need to improve management of immunosuppression, which incurs greater risks of opportunistic infections and Epstein-Barr virus-induced malignancy during childhood. High-dose immunosuppression and recurrent rejection after intestine transplantation also result in a 5-year graft loss rate of up to 50%. Such outcomes seem increasingly unacceptable because children can experience rejection-free survival with reduced immunosuppression. Pleximmune test sensitivity and specificity for predicting acute cellular rejection is 84% and 80% respectively in training set-validation set testing of 214 children. Among existing gold standards, the biopsy detects but cannot predict rejection. Anti-donor antibodies, which presage antibody-mediated injury, reflect late-stage allosensitization as a downstream effect of engagement between recipient and donor cells. Therefore, durable graft and patient outcomes also require accurate management of cellular immune responses in clinical practice.

Energy expenditure and growth failure after intestinal transplantation: A case report

We present a 12-yr-old boy who received a combined liver-pancreas small bowel transplantation at the age of two. The post-operative period was complicated by wound closure problems resulting in a large asymptomatic abdominal wall defect. Further follow-up was uneventful, with the exception of new onset growth failure not explained by extensive routine investigations. An indirect calorimetry was performed. The resting energy expenditure (REE) was significantly increased (126% of predicted), demanding a daily caloric intake of 123 kcal/kg body weight (normal for age: 80 kcal/kg). In the absence of classic reasons for increased REE, a thermal camera revealed increased dermal heat loss at the abdominal wall defect (estimated surplus in energy loss of at least 29 kcal/day: 10.4% of the elevated REE). In addition, we found lower total lung capacity due to impaired abdominal breathing. In the exploration of growth failure in children after (ITx), increased REE must be taken into account. Indirect calorimetry can serve as a valuable diagnostic tool for evaluating individual energy requirements and nutritional support. In this child, exaggerated heat loss through an aberrant abdominal wall could be a potential important contributor to the patient's increased energy requirements.

Risks and Epidemiology of Infections After Intestinal Transplantation

Intestinal transplantation has become a well-accepted and successful procedure to save the lives of patients suffering from intestinal failure and who have developed life-threatening complications of parenteral nutrition. Advances in all aspects of care, from the role of multidisciplinary intestinal rehabilitation services prior to transplant to the development strategies for early recognition of infectious sequelae and even the increasing availability of preventive strategies, have led to improved outcomes and a dramatic decline in infection-associated morbidity and mortality in children undergoing intestinal transplantation. Improvements in surgical techniques and immunosuppressive regimens have been essential components in these improvements, reducing risk of infection through reduction of technical complications and more optimal immunosuppression regimens. In addition, the development of molecular tools for early recognition of viral pathogens and an understanding of the timing and risks for infection have allowed for earlier and more successful treatments. Despite these improvements, infectious sequelae remain an important problem in this population, and additional efforts are needed to further minimize the risk of infectious sequelae in those children requiring this procedure.

IDO expressing dendritic cells suppress allograft rejection of small bowel transplantation in mice by expansion of Foxp3+ regulatory T cells

BACKGROUND

Indoleamine 2,3-dioxygenase (IDO), the enzyme that catalyzes the first and rate-limiting step of tryptophan catabolism, suppresses T-cell responses by tryptophan depletion and accumulation of kynurenine metabolites. IDO prevents allograft rejection in various transplantations.

METHODS

Dendritic cells (DC) highly expressing IDO (IDO(+) DC) were cultured through transduction of adenovirus vectors carrying the IDO sequence. IDO(+) DC were incubated with CD4(+) CD25(-) T cells to detect T cell proliferation. The effects of IDO(+) DC and 3-Hydroxyanthranilic acid (3-HAA) were verified in an allogeneic murine small bowel transplantation (SBT) model. Foxp3(+) Treg cells of recipient mice were detected by flow cytometry and cytokines in plasma were determined by ELISA.

RESULTS

IDO(+) DC effectively suppressed proliferation of CD4(+) CD25(-) T cells in vitro, and this effect could be enhanced by adding 3-HAA. In the SBT transplantation model, both 3-HAA (P < 0.05) and IDO(+) DC (P < 0.01) prolonged the survival time of transplanted mice. Mice treated with IDO(+) DC achieved longer mean survival time than 3-HAA administrated mice (11.5d vs. 18.5d). Grafts from IDO(+) DC, 3-HAA and combination treatment group showed reduced inflammation and minimal architectural distortion. IFN-γ production was significantly inhibited by IDO(+) DC and 3-HAA (P<0.05). The expression of IL-2 was slightly lower with 3-HAA or IDO(+) DC treatment. However, IL-10 was higher in 3-HAA, IDO(+) DC and combination treatment groups, while TGF-β was elevated in all non-control groups.

CONCLUSIONS

IDO(+) DC plus 3-HAA has an immunoprotective role and represents a potential strategy to suppress acute rejection and prolong survival of grafts in SBT.

The natural history of cirrhosis from parenteral nutrition-associated liver disease after resolution of cholestasis with parenteral fish oil therapy

OBJECTIVE

To determine the natural history of cirrhosis from parenteral nutrition-associated liver disease (PNALD) after resolution of cholestasis with fish oil (FO) therapy.

BACKGROUND

Historically, cirrhosis from PNALD resulted in end-stage liver disease, often requiring transplantation for survival. With FO therapy, most children now experience resolution of cholestasis and rarely progress to end-stage liver disease. However, outcomes for cirrhosis after resolution of cholestasis are unknown and patients continue to be considered for liver/multivisceral transplantation.

METHODS

Prospectively collected data were reviewed for children with cirrhosis because of PNALD who had resolution of cholestasis after treatment with FO from 2004 to 2012. Outcomes evaluated included need for liver/multivisceral transplantation, mortality, and the clinical progression of liver disease.

RESULTS

Fifty-one patients with cirrhosis from PNALD were identified, with 76% demonstrating resolution of cholestasis after FO therapy. The mean direct bilirubin decreased from 6.4 ± 4 mg/dL to 0.2 ± 0.1 mg/dL (P < 0.001) 12 months after resolution of cholestasis, with a mean time to resolution of 74 days. None of the patients required transplantation or died from end-stage liver disease. Pediatric End-Stage Liver Disease scores decreased from 16 ± 4.6 to -1.2 ± 4.6, 12 months after resolution of cholestasis (P < 0.001). In children who remained PN-dependent, the Pediatric End-Stage Liver Disease score remained normal throughout the follow-up period.

CONCLUSIONS

Cirrhosis from PNALD may be stable rather than progressive once cholestasis resolves with FO therapy. Furthermore, these patients may not require transplantation and show no clinical evidence of liver disease progression, even when persistently PN-dependent.

Enteral autonomy in pediatric short bowel syndrome: predictive factors one year after diagnosis

PURPOSE

This study examined predictors of achieving enteral autonomy among pediatric short bowel syndrome (SBS) patients remaining on parenteral nutrition (PN) beyond one year.

METHODS

A retrospective single-institution study of 171 pediatric SBS patients (defined as ≥50% small bowel (SB) loss or ≥60 days of PN with onset before 6 weeks of age) was performed. Multivariate Cox proportional hazards analysis was conducted, with subgroup analysis of patients on PN for ≥1 year (n=59). Primary outcome was successful wean from PN.

RESULTS

Over a follow-up of 4.1±4.8 years, 64.3% of children weaned from PN. Mortality was 15.2%. Presence of ≥10% expected SB length (hazard ratio [HR] 6.48, p=0.002) or an ileocecal valve (ICV; HR, 2.86, p<0.001) predicted PN weaning. Of those on PN ≥1 year, the wean rate was 50.8%, and ICV no longer predicted weaning (p=0.153). Predictors among those on PN ≥1 year were: ≥10% expected SB length (HR, 8.27, p=0.010), intestinal atresia (HR, 4.26, p=0.011), and necrotizing enterocolitis (NEC, HR, 2.84, p=0.025).

CONCLUSIONS

SBS children on PN ≥1 year continue to wean from PN, and those with ≥10% of predicted SB length, NEC, or atresia are more likely to do so. These findings may help direct management and advice for these challenging patients.

Intestinal transplant registry report: global activity and trends

The Registry has gathered information on intestine transplantation (IT) since 1985. During this time, individual centers have reported progress but small case volumes potentially limit the generalizability of this information. The present study was undertaken to examine recent global IT activity. Activity was assessed with descriptive statistics, Kaplan-Meier survival curves and a multiple variable analysis. Eighty-two programs reported 2887 transplants in 2699 patients. Regional practices and outcomes are now similar worldwide. Current actuarial patient survival rates are 76%, 56% and 43% at 1, 5 and 10 years, respectively. Rates of graft loss beyond 1 year have not improved. Grafts that included a colon segment had better function. Waiting at home for IT, the use of induction immune-suppression therapy, inclusion of a liver component and maintenance therapy with rapamycin were associated with better graft survival. Outcomes of IT have modestly improved over the past decade. Case volumes have recently declined. Identifying the root reasons for late graft loss is difficult due to the low case volumes at most centers. The high participation rate in the Registry provides unique opportunities to study these issues.

Short bowel syndrome in children: surgical and medical perspectives

The main cause of intestinal failure in children is due to short bowel syndrome (SBS) resulting from congenital or acquired intestinal lesions. From the first lengthening procedure introduced by Bianchi, the last three decades have seen lengthening procedures established as fundamental components of multidisciplinary intestinal rehabilitation programs. Debate on indications and timing of the procedures is still open leaving SBS surgical treatment a great challenge. However, enteral autonomy is possible only with an individualized approach remembering that each SBS patient is unique. Current literature on autologous gastrointestinal reconstruction technique was reviewed aiming to assess a comprehensive pathway in SBS non-transplant management.

Prolonged post-reperfusion syndrome during multivisceral organ transplantation in a pediatric patient: a case report

Multivisceral organ transplantation involves the transplantation of three or more abdominal organs, including small bowel, duodenum, stomach, liver, pancreas, colon, and so on. The large amounts of cold and acidic loading into systemic circulation from the graft during multivisceral organ transplantation may result in severe post-reperfusion syndrome (PRS). We describe here a 6-year-old pediatric patient with chronic intestinal pseudo-obstruction who experienced prolonged PRS and severe metabolic acidosis during seven abdominal organ transplantation including the liver, spleen, stomach, duodenum, small bowel, colon and pancreas. The hypotensive period lasted approximately 10 minutes after graft reperfusion and was accompanied by severe metabolic acidosis and hypothermia. Since PRS can be easily associated with adverse outcomes, such as poor early graft function and primary non-function, not only meticulous surveillance for aggravating factors for PRS but also their immediate correction were necessary in managing a pediatric patient undergoing multivisceral organ transplantation.

Mesenchymal stem cell therapy in patients with small bowel transplantation: Single center experience

AIM: To study the effects of mesenchymal stem cell (MSC) therapy on the prevention of acute rejection and graft vs host disease following small bowel transplantation.

METHODS: In our transplantation center, 6 isolated intestinal transplants have been performed with MSC therapy since 2009. The primary reasons for transplants were short gut syndrome caused by surgical intestine resection for superior mesenteric artery thrombosis (n = 4), Crohn’s disease (n = 1) and intestinal aganglionosis (n = 1). Two of the patients were children. At the time of reperfusion, the first dose of MSCs cultured from the patient’s bone marrow was passed into the transplanted intestinal artery at a dose of 1000000 cells/kg. The second and third doses of MSCs were given directly into the mesenteric artery through the arterial anastomosis using an angiography catheter on day 15 and 30 post-transplant.

RESULTS: The median follow-up for these patients was 10.6 mo (min: 2 mo-max: 30 mo). Three of the patients developed severe acute rejection. One of these patients did not respond to bolus steroid therapy. Although the other two patients did respond to anti-rejection treatment, they developed severe fungal and bacterial infections. All of these patients died in the 2^nd and 3^rd months post-transplant due to sepsis. The remaining patients who did not have acute rejection had good quality of life with no complications observed during the follow-up period. In addition, their intestinal grafts were functioning properly in the 13^th, 25^th and 30^th month post-transplant. The patients who survived did not encounter any problems related to MSC transplantation.

CONCLUSION: Although this is a small case series and not a randomized study, it is our opinion that small bowel transplantation is an effective treatment for intestinal failure, and MSC therapy may help to prevent acute rejection and graft vs host disease following intestinal transplantation.

Updates on acute and chronic rejection in small bowel and multivisceral allografts

PURPOSE OF REVIEW

The surgical management of short bowel syndrome now includes intestinal (ITx) and multivisceral transplantation (MVTx), which has advanced and is now a sustainable option for the treatment of intestinal failure. Improvements in immunosuppressive therapies, excellence in surgical and medical management and enhanced post-transplant monitoring have all contributed to optimizing this solid organ transplant as a means of supplanting the diseased native bowel and alimentary tract with a functional alternative.

RECENT FINDINGS

Post-transplant management is a critical and challenging phase of gastrointestinal transplantation, and the transplant pathologist is an essential member of the transplant team who identifies many of the early and late complications after ITx and MVTx. Among the most injurious and common complications of ITx and MVTx is acute rejection and, to a lesser degree, chronic rejection. Both of these broad categories of rejection are principally identified by histopathological changes in the allograft; however, biomarkers and other laboratory analytes are rapidly evolving into critical ancillary tools in identifying and further characterizing the rejection process. Thus, the transplant pathologist must also be able to utilize numerous other laboratory tests and panels of molecular biomarkers that provide supplementary information to accompany the biopsy interpretation and clinical suspicion of rejection.

SUMMARY

Using biopsies and an assortment of additional approaches, the transplant pathologist is now able to provide swift and detailed information regarding the rejection process in the gastrointestinal transplant. This enables the clinical team to properly and successfully intercede, contributing to enhanced patient and graft survival.

Social circumstances and medical complications in children with intestinal failure

Although most children discharged on home parenteral nutrition (HPN) will achieve enteral autonomy, some remain parenteral nutrition dependent; those who develop life-threatening complications may undergo small bowel transplantation (SBTx). The aim of this study was to investigate the relationship between social circumstances, compliance and complications.

SUBJECTS AND METHODS

An observational study in 2008-2012 on 64 children (34 HPN, 30 SBTx) from three units (two regional gastroenterology; one transplant). Social circumstances were assessed routinely as part of discharge planning; adherence by families to home care management was scored, and episodes of catheter-related blood stream infection and graft rejection were recorded for 2 years and related to compliance and social circumstances.

RESULTS

A quarter of families had a disadvantaged parent: non-English speaking (n=11), unable to read (n=5), physical disability (n=3), mental health problems disclosed (n=10); 20% children were cared for by a lone parent. Discharge home was delayed by social factors (n=9) and need for rehousing (n=17, 27%). 17/34 (50%) of HPN and 12/30 (40%) of transplant families were assessed as fully adherent. 10 families were assessed as non-adherent, eight were subject to child protection review and care was taken over by another family member (n=3) or foster parents (n=2). The risk of catheter-related blood stream infection was increased by parental disadvantage and age <3 years (p<0.05). Poor compliance was associated with complications in HPN and SBTx recipients.

CONCLUSIONS

Children receiving complex home care may be socially isolated and measures to support improved compliance such as increased community support, social care involvement and respite care may improve outcomes.

Growth following solid organ transplantation in childhood

One of the ultimate goals of successful transplantation in pediatric solid organ transplant recipients is the attainment of optimal final adult height. This manuscript will discuss the attainment of height following solid organ transplantation in pediatric recipients of kidney, liver, heart, lung, and small bowel transplantation. Age is a primary factor with younger recipients exhibiting the greatest immediate catch up growth. Graft function is a significant contributory factor with a reduction in glomerular filtration rate correlating with poor growth in kidney recipients and the need for re-transplantation with impaired growth in liver recipients. The known adverse impact of steroids on growth has led to modification of steroid dosage and even to steroid withdrawal and steroid avoidance. In kidney and liver recipients, this has been associated with the development on occasion of acute rejection episodes. In infant heart transplantation, avoidance of maintenance corticosteroid immunosuppression is associated with normal growth velocity in the majority of patients. With marked improvement in patient and graft survival rates in pediatric organ graft recipients, it is timely that the quality of life issues, such as normal adult height, receive paramount attention. In general, normal growth post-transplantation should be an achievable goal that results in normal adult height for many solid organ transplantation recipients.

Neurologic aspects of multiple organ transplantation

Complex multiorgan failure may require simultaneous transplantation of several organs, including heart-lung, kidney-pancreas, or multivisceral transplantation. Solid organ transplantation can also be combined with hematopoietic stem cell transplantation to modulate immunologic response to a solid organ allograft. Combined multiorgan transplantation may offer a lower rate of allograft rejection and lower immunosuppression needs. In recent years, intestinal and multivisceral transplantations became viable as a rescue treatment for patients with irreversible intestinal failure who can no longer tolerate total parenteral nutrition with 70% survival after 5 years which is comparable to other types of solid organ allografts. Post-transplant neurologic complications were reported in up to 86% of allograft recipients and greatly overlap in intestinal and multivisceral allograft recipients, without a significant effect on the outcome of transplantation. Other common organ combinations in multiorgan transplantation include kidney-pancreas, which is mostly used for patients with renal failure and uncontrolled diabetes, and heart-lung for patients with congenital heart disease and idiopathic pulmonary arterial hypertension. Kidney-pancreas transplantation frequently results in an improvement of diabetic complications, including diabetic neuropathy. Heart-lung allograft recipients have very similar clinical course and spectrum of neurologic complications to lung transplant recipients. At this time there are no reports of an increased risk of graft-versus-host disease with combined transplantation of solid organ allograft and hematopoietic stem cells. Chronic immunosuppression and complex toxic-metabolic disturbances after multiorgan transplantation create a permissive environment for development of a wide spectrum of neurologic complications which largely resemble complications after transplantations of individual components of complex multiorgan allografts.

Growth following solid organ transplantation in childhood

One of the ultimate goals of successful solid organ transplantation in pediatric recipients is attaining an optimal final adult height. This manuscript will discuss growth following transplantation in pediatric recipients of kidney, liver, heart, lung or small bowel transplants. Remarkably similar factors impact growth in all of these recipients. Age is a primary factor, with younger recipients exhibiting the greatest immediate catch-up growth. Graft function is a significant contributing factor, with a reduced glomerular filtration rate correlating with poor growth in kidney recipients and the need for re-transplantation with impaired growth in liver recipients. The known adverse impact of steroids on growth has led to modification of the steroid dose and even steroid withdrawal and avoidance. In kidney and liver recipients, this strategy has been associated with the development of acute rejection. In infant heart transplantation, avoiding maintenance corticosteroid immunosuppression is associated with normal growth velocity in the majority of patients. With marked improvements in patient and graft survival rates in pediatric organ recipients, quality of life issues, such as normal adult height, should now receive paramount attention. In general, normal growth following solid organ transplantation should be an achievable goal that results in normal adult height.

Neurologic complications of pancreas and small bowel transplantation

In the past decade, substantial improvements in patient and graft survival for pancreas and small bowel transplants have been achieved. Despite this progress, many patients still develop neurologic complications in the course of their illness. Small bowel transplants produce more neurologic complications because of the complex metabolic environment in which the procedure is performed and because of the intense immune suppression necessitated by the greater immunogenicity of the intestinal mucosa. Pancreas transplants stabilize and/or improve the signs and symptoms of diabetic neuropathy over time. Because transplantation of the pancreas is often coupled with a kidney transplant and small intestine with liver, neurologic complications in these patients sometimes reflect problems involving the organ partner or both organs. The spectrum of neurologic complications for pancreas and small bowel transplant recipients is similar to other organ transplants but their frequency varies depending on the type of transplant performed.

Management of short bowel syndrome

Most intestinal failure in children is due to short bowel syndrome (SBS) where congenital or acquired lesions have led to an extensive loss of intestinal mass. The vast majority of morbidity and mortality of patients with SBS is due to complications secondary to their long term dependence on parenteral nutrition. In response to SBS, the intestine undergoes a process of remodeling termed adaptation. Principles guiding the medical management of SBS include providing adequate parenteral nutrition, fluids and electrolytes for growth and normal development, promoting small bowel adaptation, and preventing and treating complications related to the patient's underlying disease and their parenteral nutrition. Catheter associated blood stream infection (CABSI) is major source of morbidity and mortality in patients with intestinal failure from SBS. Intestinal failure associated liver disease (IFALD)is another major source of morbidity and mortality in patients with SBS. IFALD is the most consistent negative predictor of outcome including death and continued parenteral nutrition dependence. Enteral nutrition is critical for intestinal adaptation and preventing IFALD. Patients with SBS who develop dilated dysmotile segments may benefit from autologous intestinal reconstruction surgery (AIRS) with the goal of decreasing stasis and disordered motility through intestinal narrowing and lengthening. Patients with SBS should be referred for transplantation if they have failed intestinal rehabilitation including AIRS, have no reasonable chance for enteral feeding tolerance, develop irreversible IFALD, have recurrent sepsis, or have exhausted their central venous access sites. With improvements in medical and surgical care, overall survival of patients with SBS now exceeds 90%.

Updated international consensus guidelines on the management of cytomegalovirus in solid-organ transplantation

Cytomegalovirus (CMV) continues to be one of the most common infections after solid-organ transplantation, resulting in significant morbidity, graft loss, and adverse outcomes. Management of CMV varies considerably among transplant centers but has been become more standardized by publication of consensus guidelines by the Infectious Diseases Section of The Transplantation Society. An international panel of experts was reconvened in October 2012 to revise and expand evidence and expert opinion-based consensus guidelines on CMV management, including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues. The following report summarizes the recommendations.

Intestinal absorption rate in children after small intestinal transplantation

BACKGROUND

Small bowel transplantation has now become a recognized treatment of irreversible, permanent, and subtotal intestinal failure.

OBJECTIVE

The aim of this study was to assess intestinal absorption at the time of weaning from parenteral nutrition in a series of children after intestinal transplantation.

DESIGN

Twenty-four children (age range: 14-115 mo) received intestinal transplantation, together with the liver in 6 children and the colon in 16 children. Parenteral nutrition was slowly tapered while increasing enteral tube feeding. The absorption rate was measured from a 3-d stool balance analysis performed a few days after the child had weaned from parenteral nutrition to exclusive enteral tube feeding. Results were analyzed according to the resting energy expenditure (REE; Schofield formula).

RESULTS

All children were weaned from parenteral nutrition between 31 and 85 d posttransplantation. Median intakes were as follows: energy, 107 kcal · kg(-1) · d(-1) (range: 79-168 kcal · kg(-1) · d(-1)); lipids, 39 kcal · kg(-1) · d(-1) (range: 20-70 kcal · kg(-1) · d(-1)); and nitrogen, 17 kcal · kg(-1) · d(-1) (range: 11-27 kcal · kg(-1) · d(-1)). Median daily stool output was 998 mL/d (range: 220-2025 mL/d). Median absorption rates were 88% (range: 75-96%) for energy, 82% (range: 55-98%) for lipids, and 77% (range: 61-88%) for nitrogen. The ratios for ingested energy to REE and absorbed energy to REE were 2.2 (range: 1.6-3.6) and 1.8 (range: 1.3-3.3), respectively.

CONCLUSION

These data indicate a suboptimal intestinal graft absorption capacity with fat malabsorption, which necessitates energy intakes of at least twice the REE.

Mucosal plasma cell barrier disruption during intestine transplant rejection

BACKGROUND

Intestinal allograft mucosa undergoes repopulation with host immunocytes. However, critical changes within key immunocyte subsets are not known.

METHODS

To explain acute cellular rejection after intestine transplantation (ITx) on the basis of altered mucosal immunocytes, rejecting and rejection-free ITx allografts (n=17) were compared with genome-wide expression arrays. Cells identified by cell/lineage-specific genes were evaluated by immunohistochemistry. The corresponding phenotype and donor-specific alloreactivity were characterized in peripheral blood. Time-dependent changes in candidate cell(s) were evaluated in biopsies from an independent cohort of 12 children with ITx.

RESULTS

Among 107 differentially expressed genes, three B-cell lineage-specific genes, CCR10, STAP1, and IGLL1, were down-regulated during ITx rejection and were selected for and achieved technical quantitative reverse transcription polymerase chain reaction replication. Down-regulation of the immunoglobulin (Ig)A+ plasma cell-specific CCR10 gene correlated with decreased mature mucosal CD138+ plasma cell numbers in corresponding biopsy specimens (r=0.761, P=0.006) and inversely correlated with enhanced alloreactivity of CD154+ T-cytotoxic memory cells (r=-0.56, P=0.031), which predict acute cellular rejection with high sensitivity. An independent cohort of serial biopsy specimens from 12 ITx recipients (1) confirmed relative CD138+ plasma cell depletion during rejection (P=0.042) and (2) showed increased IgG+-to-IgA+ cell ratios within 4 hr of reperfusion in rejection-prone allografts (P=0.037) and during ITx rejection (P=0.025), compared with rejection-free allografts. No differences existed late after ITx. Increased peripheral IgG+ CD27+ CD19+ memory B cells (P=0.004) were seen during ITx rejection in archived peripheral blood lymphocyte from test and replication cohorts.

CONCLUSIONS

Protracted depletion of the mucosal CD138+ plasma cell barrier and early mucosal infiltration with memory IgG+ cells characterize the rejection-prone intestine allograft. Mucosal IgA+ plasma cell barrier reconstitution may augur resolution of ITx rejection.

Age-based disparity in outcomes of intestinal transplants in pediatric patients

Outcomes of intestinal transplants (ITx; n = 977) for pediatric patients are examined using the United Network for Organ Sharing data from 1987 to 2009. Recipients were divided into four age groups: (1) <2 years of age (n = 569), (2) 2-6 years (n = 219), (3) 6-12 years (n = 121) and (4) 12-18 years (n = 68). Of 977 ITx, 287 (29.4%) were isolated ITx and 690 (70.6%) were liver and ITx (L-ITx). Patient survival for isolated ITx at 1, 3 and 5 years, 85.3%, 71.3% and 65.0%, respectively, was significantly better than L-ITx, 68.4%, 57.0% and 51.4%, respectively, (p = 0.0001); this was true for all age groups, except for patients <2 years of age. The difference in graft survival between isolated ITx and L-ITx was significant at 1 and 3 years (Wilcoxon test, p = 0.0012). After attrition analysis of graft survival of patients who survived past first year, 3 and 5 years, graft survival for L-ITx patient was significantly better than those for isolated ITx. Isolated ITx should be considered early before the onset of liver disease in children >2 with intestinal failure but is not advantageous in patients <2 years.

Small-Bowel Allograft Biopsies in the Management of Small-Intestinal and Multivisceral Transplant Recipients: Histopathologic Review and Clinical Correlations

Context.—Intestinal transplant has become a standard treatment option in the management of patients with irreversible intestinal failure. The histologic evaluation of small-bowel allograft biopsy specimens plays a central role in assessing the integrity of the graft. It is essential for the management of acute cellular and chronic rejection; detection of infections, particularly with respect to specific viruses (cytomegalovirus, adenovirus, Epstein-Barr virus); and immunosuppression-related lymphoproliferative disease.

Objective.—To provide a comprehensive review of the literature and illustrate key histologic findings in small-bowel biopsy specimen evaluation of patients with small-bowel or multivisceral transplants.

Data Sources.—Literature review using PubMed (US National Library of Medicine) and data obtained from national and international transplant registries in addition to case material at Columbia University, Presbyterian Hospital, and Mount Sinai Medical Center, New York, New York.

Conclusions.—Key to the success of small-bowel transplantation and multivisceral transplantation are the close monitoring and appropriate clinical management of patients in the posttransplant period, requiring coordinated input from all members of the transplant team with the integration of clinical, laboratory, and histopathologic parameters.

Nonsurgical care of intestinal and multivisceral transplant recipients: a review for the intensivist

Intestinal and multivisceral transplantation has evolved from an experimental procedure to the treatment of choice for patients with irreversible intestinal failure and serious complications related to long-term parenteral nutrition. Increased numbers of transplant recipients and improved survival rates have led to an increased prevalence of this patient population in intensive care units. Management of intestinal and multivisceral transplant recipients is uniquely challenging because of complications arising from the high incidence of transplant rejection and its treatment. Long-term comorbidities, such as diabetes, hypertension, chronic kidney failure, and neurological sequelae, also develop in this patient population as survival improves. This article is intended for intensivists who provide care to critically ill recipients of intestinal and multivisceral transplants. As perioperative care of intestinal/multivisceral transplant recipients has been described elsewhere, this review focuses on common nonsurgical complications with which one should be familiar in order to provide optimal care. The article is both a review of the current literature on multivisceral and isolated intestinal transplantation as well as a reflection of our own experience at the University of Miami.

Increased monocyte expression of sialoadhesin during acute cellular rejection and other enteritides after intestine transplantation in children

BACKGROUND

Sialoadhesin (CD169) facilitates T-cell priming when overexpressed on inflammatory monocytes. Monocyte-derived macrophages prime acute cellular rejection after intestine transplantation (ITx).The purpose of this study was to evaluate whether CD169-expressing activated monocytes associate with or predict ITx rejection.

METHODS

After informed consent (ClinicalTrials.gov NCT No. 01163578), activated CD169+CD14+monocytes were measured by flow cytometry in five normal healthy adult volunteers (group A), and 56 children with ITx sampled cross-sectionally (group B, 26), longitudinally (group C, 18), or during infection/inflammation without rejection (group D: acute enteritis, 9; Helicobacter pylori, 1; Streptococcal pharyngitis 1; and posttransplant lymphoma, 1). Activated monocytes were tested for correlations with donor-specific alloreactivity in simultaneous mixed lymphocyte co-cultures.

RESULTS

Median age was 3 years (range 0.5-21 yr), and distribution of ITx-alone:combined liver-ITx was 25:31. Higher frequencies (%) of activated monocytes were seen during rejection in group B and infection/inflammation without rejection in group D (58 ± 28 and 73 ± 26), compared with nonrejectors or normal controls (10.6 ± 7.9 or 10.7 ± 6.5, P=0.001). In longitudinal monitoring, rejectors also showed higher activated monocyte frequencies (%) before ITx (64 ± 26 vs. 13.4 ± 8.6, P=0.0007) and during acute cellular rejection (55 ± 28 vs. 22.4 ± 15, P=0.006) when compared with nonrejectors. Activated monocytes correlated significantly with allospecific CD154+T-cytotoxic memory cells (Spearman r=0.688, P=7.1E-05) and CD154+B cells (r=0.518, P=0.005) in ITx recipients without inflammation/infection but not in group D.

CONCLUSIONS

Monocytes overexpress sialoadhesin nonspecifically during ITx rejection and systemic or enteritic inflammatory states. When combined with allospecific T and B cells, this information may differentiate between rejection and other enteritides.

Intestinal rehabilitation and bowel reconstructive surgery: improved outcomes in children with short bowel syndrome

BACKGROUND AND AIM

Short bowel syndrome poses a great challenge to pediatric teams. Several innovative techniques in the management of total parenteral nutrition (TPN) and bowel reconstructive surgery have improved the outcomes of these children. The authors present their experience during the last decade as a specialist unit using improved techniques and multidisciplinary approaches in the management of this condition.

METHODS

All of the children presenting with short bowel syndrome between 2000 and 2009 were identified. Diagnosis, length of residual gut, age at definitive surgery, length of gut prelengthening, length of gut postlengthening, TPN status, and survival were recorded. Median values were calculated.

RESULTS

Twenty-seven children were identified (14 boys, 13 girls). Overall survival was 92%. Two children died. Nineteen children required bowel lengthening and 8 children had simple bowel reconstruction while on our protocol. Overall median age at definitive surgery was 12 months. Overall median residual gut length for these was 35.5 cm, whereas the median residual gut length for patients undergoing bowel lengthening was 25 cm. Postbowel lengthening, the median gut length was 90 cm. TPN data were unavailable for 2 patients. Overall, excluding the 2 patients who died and the 2 we have no TPN data on, of 23 patients, 21 (91%) are now off TPN.

CONCLUSIONS

Our series shows improved results not only with survival but also in the number of patients that are off TPN. Multidisciplinary approach consisting of both medical and surgical expertise is necessary in the management of these patients. The authors advocate centralisation of short gut services to experienced centers with multidisciplinary expertise.

Current status of pediatric intestinal failure, rehabilitation, and transplantation: summary of a colloquium

An international symposium convened September 9-11, 2010, in Chicago to present the state of the art and science of the multidisciplinary care of intestinal failure in children. Medical and surgical management of the child with intestinal failure was presented with a focus on the importance of multidisciplinary intestinal failure management. Issues of timing of referral and benefit risk analysis for intestine "rehabilitation" and transplant were presented. Areas of opportunity such as increased donor recovery, improvement of long-term transplant outcomes, optimization of immune monitoring, and quality-of-life outcomes were reviewed.

Allospecific CD154 + T-cytotoxic memory cells as potential surrogate for rejection risk in pediatric intestine transplantation

Clinical end-points dictate large trial enrollments and exclude children with the rare intestine transplant procedure (ITx), who experience higher drug-related morbidity. We evaluate the novel rejection-risk parameter, allo-(antigen)-specific CD154 + TcMs (i) as surrogates for ACR using Prentice's criteria, (ii) for association with immunosuppression targets to determine Fleming's surrogate end-point designation, and (iii) as time-to-event end-point in a simulated comparison of alemtuzumab (NCT#01208337, n = 14) and rabbit anti-human thymocyte globulin (rATG, n = 16) among 30 children with ITx. CD154 + TcM were measured in MLR before, and at 1-60 and 61-200 days after ITx (NCT#01163578). CD154 + TcM correlate significantly with rejection severity (Spearman r = 0.685, p = 2.03E-5) and associate with biopsy-proven ITx rejection with sensitivity/specificity of 94%/84% [corrected] independent of immunosuppressant. Previously stated sensitivity of 90% is incorrect. [corrected]. The rejection-risk threshold of CD154 + TcM resolves rapidly in 200-day follow-up (46 ± 20 vs. 158 ± 59 days, p = 0.009, K-M) with alemtuzumab, which demonstrates lower 90-day ACR incidence (50% vs. 69%, p=NS, Fisher's exact), and is associated with accelerated prednisone minimization to ≤2.5 mg/day, compared with rATG (120 ± 28 vs. 180 ± 30 days, p = 0.027, K-M). As a surrogate end-point, time-to-rejection-risk resolution measured with CD154 + TcM portends 50% reduction in sample sizes in a simulated trial of alemtuzumab vs. rATG. Rejection-risk assessment with CD154 + TcM may enable informed immunosuppression minimization, and preliminary efficacy comparisons in pediatric ITx.