Intestinal transplantation: An overview

Association between oral nutrition and inflammation after intestinal transplantation

Intestinal transplantation (Itx) can be a life-saving treatment for certain patient populations, including those patients with intestinal failure (IF) who develop life-threatening complications due to the use of parenteral nutrition (PN). Most patients who have undergone Itx are eventually able to tolerate a full oral diet. However, little guidance or consensus exists regarding optimizing the specific components of an oral diet for Itx patients, including macronutrients, micronutrients and dietary patterns. While oral dietary prescriptions have moved to the forefront of primary and preventive care, this movement has yet to occur across the field of organ transplantation. Evidence to date points to the role of systemic chronic inflammation (SCI) in a wide variety of chronic diseases as well as post-transplant graft dysfunction. This review will discuss current trends in oral nutrition for Itx patients and also offer novel insights into nutritional management techniques that may help to decrease SCI and chronic disease risk as well as optimize graft function.

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.

Gastrointestinal Neuropathies: New Insights and Emerging Therapies

The bewildering complexity of the enteric nervous system makes it susceptible to develop a wide array of motility disorders, collectively called enteric neuropathies. These gastrointestinal conditions are among the most challenging to manage, mainly given poor characterization of their etiopathophysiology and outcomes. Not surprisingly, therefore, targeted or curative therapies for enteric neuropathies are lacking and management is largely symptomatic. Nonetheless, recent advances in neurogastroenterology have witnessed improvements in established strategies, such as intestinal transplantation and the emergence of new treatments including novel drugs, electrical pacing, and manipulation of fecal microbiota, as well as stem cell and gene therapy.

Paediatric Intestinal Pseudo-obstruction: Evidence and Consensus-based Recommendations From an ESPGHAN-Led Expert Group

OBJECTIVES

Chronic intestinal pseudo-obstructive (CIPO) conditions are considered the most severe disorders of gut motility. They continue to present significant challenges in clinical care despite considerable recent progress in our understanding of pathophysiology, resulting in unacceptable levels of morbidity and mortality. Major contributors to the disappointing lack of progress in paediatric CIPO include a dearth of clarity and uniformity across all aspects of clinical care from definition and diagnosis to management. In order to assist medical care providers in identifying, evaluating, and managing children with CIPO, experts in this condition within the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition as well as selected external experts, were charged with the task of developing a uniform document of evidence- and consensus-based recommendations.

METHODS

Ten clinically relevant questions addressing terminology, diagnostic, therapeutic, and prognostic topics were formulated. A systematic literature search was performed from inception to June 2017 using a number of established electronic databases as well as repositories. The approach of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to evaluate outcome measures for the research questions. Levels of evidence and quality of evidence were assessed using the classification system of the Oxford Centre for Evidence-Based Medicine (diagnosis) and the GRADE system (treatment). Each of the recommendations were discussed, finalized, and voted upon using the nominal voting technique to obtain consensus.

RESULTS

This evidence- and consensus-based position paper provides recommendations specifically for chronic intestinal pseudo-obstruction in infants and children. It proposes these be termed paediatric intestinal pseudo-obstructive (PIPO) disorders to distinguish them from adult onset CIPO. The manuscript provides guidance on the diagnosis, evaluation, and treatment of children with PIPO in an effort to standardise the quality of clinical care and improve short- and long-term outcomes. Key recommendations include the development of specific diagnostic criteria for PIPO, red flags to alert clinicians to the diagnosis and guidance on the use of available investigative modalities. The group advocates early collaboration with expert centres where structured diagnosis and management is guided by a multi-disciplinary team, and include targeted nutritional, medical, and surgical interventions as well as transition to adult services.

CONCLUSIONS

This document is intended to be used in daily practice from the time of first presentation and definitive diagnosis PIPO through to the complex management and treatment interventions such as intestinal transplantation. Significant challenges remain to be addressed through collaborative clinical and research interactions.

Long-Term Outcomes of Intestinal and Multivisceral Transplantation at a Single Center in Argentina

BACKGROUND

Intestinal failure (IF) patients received parenteral nutrition (PN) as the only available therapy until intestinal transplantation (ITx) evolved as an accepted treatment. The aim of this article is to report the long-term outcomes of a series of ITx performed in pediatric and adult patients at a single center 9 years after its creation.

PATIENTS AND METHODS

This is a retrospective analysis of the ITx performed between May 2006 and January 2015. Diagnoses, pre-ITx mean time on PN, indications for ITx, time on the waiting list for types of ITx, mean total ischemia time, and warm ischemia time, time until PN discontinuation, incidence of acute and chronic rejection, and 5-year actuarial patient survival are reported.

RESULTS

A total of 42 patients received ITx; 80% had short gut syndrome (SG); the mean time on PN was 1620 days. The main indication for ITx was lack of central venous access followed by intestinal failure-associated liver disease (IFALD) and catheter-related infectious complications. The mean time on the waiting list was 188 days (standard deviation, ±183 days). ITx were performed in 26 children and 14 adults. In all, 32 procedures were isolated ITx (IITX); 10 were multiorgan Tx (MOT; 3 combined, 7 multivisceral Tx (MVTx), 1 modified MVTx and 2 with kidney); 2 (4.7 %) were retransplantations: 1 IITx, 1 MVTx, and 5 including the right colon. Thirteen patients (31%) received abdominal rectus fascia. All procedures were performed by the same surgical team. Total ischemia time was 7:53 ± 2:04 hours, and warm ischemia time was 40.2 ± 10.5 minutes. The mean length of implanted intestine was 325 ± 63 cm. Bishop-Koop ileostomy was performed in 67% of cases. In all, 16 of 42 Tx required early reoperations. The overall mean follow-up time was 41 ± 35.6 months. The mean time to PN discontinuation after Tx was 68 days (P = .001). The total number of acute cellular rejection (ACR) episodes until the last follow-up was 83; the total number of grafts lost due to ACR was 4; and the total graft lost due to chronic rejection was 3. At the time of writing, the overall 5-year patient survival is 55% (65% for IITx vs 22% for MOT; P = .0001); 60% for pediatric recipients vs 47% for adults (P = NS); 64% when the indication for ITx was SG vs 25% for non-SG (P = .002).

CONCLUSIONS

At this center, candidates with SG, in the absence of IFALD requiring IITx, showed the best long-term outcomes, independent of recipient age. A multidisciplinary approach is mandatory for the care of intestinal failure patients, to sustain a rehabilitation and transplantation program over time.

Orthotopic liver transplant for multifocal lymphangioendotheliomatosis with thrombocytopenia

An eight-yr-old female with a history of multifocal lymphangioendotheliomatosis and thrombocytopenia presented for MVT. The patient had multiple vascular lesions in the skin and stomach in infancy. Although her cutaneous lesions resolved with vincristine and methylprednisolone, her gastric lesions persisted. Eight yr later, she was diagnosed with portal hypertension and decompensating liver function despite therapy with bevacizumab, propranolol, furosemide, and spironolactone. Upon presentation, she was found to have a Kasabach-Merritt-like coagulopathy in association with multiple lesions in her GI tract and persistent gastric lesions. Although treatment with methylprednisolone and sirolimus normalized her coagulation factors and d-dimer levels, she never developed sustained improvement in her thrombocytopenia. Her liver function continued to deteriorate and she developed hepatorenal syndrome. Given better outcomes after OLT in comparison with MVT, she underwent OLT, with the plan to manage her GI lesions with APC post-transplant. Post-transplant, her liver function and coagulopathy normalized, and GI tract lesions disappeared upon screening with capsule endoscopy. The patient is doing well, without recurrence of either GI lesions or thrombocytopenia, at 18 months after transplantation.

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.

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.