Intestinal transplantation: current outcomes and opportunities. Curr Opin Organ Transplant. 2009;14:515-521. [PMID: 19623070 DOI: 10.1097/mot.0b013e328330680d]

Mechanistic Understanding of EBV+Lymphoproliferative Disease Development After Transplantation

Posttransplant lymphoproliferative disorders (PTLDs) are among the most common malignant complications after transplantation, leading to a drastic reduction in patient survival rates. The majority of PTLDs are tightly linked to Epstein-Barr virus (EBV+PTLDs) and are the result of an uncontrolled proliferation of EBV-infected cells. However, although EBV infections are a common finding in transplant recipients, most patients with high EBV loads will never develop EBV+PTLD. Natural killer cells and EBV-specific CD8+ T lymphocytes are critical for controlling EBV-infected cells, and the impairment of these cytotoxic immune responses facilitates the unfettered proliferation of EBV-infected cells. Recent years have seen a considerable increase in available literature aiming to describe novel risk factors associated with the development of EBV+PTLD, which may critically relate to the strength of EBV-specific natural killer cell and EBV-CD8+ T lymphocyte responses. The accumulation of risk factors and the increased risk of developing EBV+PTLD go hand in hand. On the one hand, most of these risk factors, such as the level of immunosuppression or the EBV donor and recipient serologic mismatch, and distinct genetic risk factors are host related and affect cytotoxic EBV-specific immune responses. On the other hand, there is growing evidence that distinct EBV variants may have an increased malignant potential and are thus more likely to induce EBV+PTLD. Here, we aim to review, from a mechanistic point of view, the risk factors for EBV+PTLD in the host and the infecting EBV variants that may explain why only a minority of transplant recipients develop EBV+PTLD.

Vacuum assisted closure for defects of the abdominal wall after intestinal transplantation

Background

Isolated intestinal transplantation (IT) is indicated in cases of intestinal failure (IF) in the absence of severe liver dysfunction. Short bowel syndrome (SBS) is the most frequent IF etiology, and due to the absence or considerable reduction of intestinal loops in the abdominal cavity in these patients, there is atrophy and muscle retraction of the abdominal wall, leading to loss of the abdominal domain and elasticity and preventing the primary closure of the abdominal wall. This study aimed to describe a technique for the closure of the abdominal wall after IT without using prostheses.

Methods

Four patients underwent IT with the impossibility of primary closure of the abdominal wall. We describe a novel technique, associating a series of vacuum-assisted closure dressings, components separation, and relaxation incisions.

Results

All patients presented a successful closure of the abdominal wall with the described technique, with no complications related to the abdominal wall.

Conclusion

The technique proved to be safe, effective, and reproducible as an option for abdominal wall closure after IT. Employing this technique in a greater number of cases is necessary to confirm these results.

Late graft loss after intestinal transplantation

PURPOSE OF REVIEW

Despite improvement in short-term outcomes after intestinal transplantation in the last 20 years, long-term rates of graft attrition and patient survival remain unchanged, with worse outcomes compared with other solid organ transplants. This review investigates the multiple causes of late graft loss, including chronic rejection, infection, graft-versus-host disease, posttransplant lymphoproliferative disorder and postsurgical complications.

RECENT FINDINGS

New insights into immunology of the intestine and evolution of immunosuppression, as well as review of current persistent causes of late graft loss, shed light on findings that may help improve long-term intestinal allograft survival.

SUMMARY

Although intestinal transplantation remains a life-saving intervention with significant advancements since its inception, further understanding of mechanisms of injury is needed to improve long-term outcomes and prevent late intestinal graft loss.

Outcomes of Adult Intestinal Transplant Recipients Requiring Dialysis and Renal Transplantation

Supplemental digital content is available in the text.

Background

Data on dialysis and renal transplantation (RT) after intestinal transplantation (IT) are sparse. Whether changes in immunosuppression and surgical techniques have modified these outcomes is unknown.

Methods

Two hundred eighty-eight adult intestinal transplants performed between 1990 and 2014 at the University of Pittsburgh were analyzed for incidence, risk factors and outcomes after dialysis and RT. Cohort was divided into 3 eras based on immunosuppression and surgical technique (1990-1994, 1995-2001, and 2001-2014). Receiving RT, or dialysis for 90 days or longer was considered as end-stage renal disease (ESRD).

Results

During a median follow-up of 5.7 years, 71 (24.7%) patients required dialysis, 38 (13.2%) required long-term dialysis and 17 (6%) received RT after IT. One-, 3-, and 5-year ESRD risk was 2%, 7%, and 14%, respectively. No significant era-based differences were noted. Higher baseline creatinine (hazard ratio [HR], 3.40 per unit increase, P < 0.01) and use of liver containing grafts (HR, 2.01; P = 0.04) had an increased ESRD risk. Median patient survival after dialysis initiation was 6 months, with a 3-year survival of 21%. Any dialysis (HR, 12.74; 95% CI 8.46-19.20; P < 0.01) and ESRD (HR, 9.53; 95% CI, 5.87-15.49; P < 0.01) had higher mortality after adjusting for covariates. For renal after IT, 1- and 3-year kidney and patient survivals were 70% and 49%, respectively. All graft losses were from death with a functioning graft, primarily related to infectious complications (55%).

Conclusions

In intestinal transplant recipients, renal failure requiring dialysis or RT is high and is associated with increased mortality. Additionally, the outcomes for kidney after IT are suboptimal due to death with a functioning graft.

Updates on antibody-mediated rejection in intestinal transplantation

Antibody-mediated rejection (ABMR) has increasingly emerged as an important cause of allograft loss after intestinal transplantation (ITx). Compelling evidence indicates that donor-specific antibodies can mediate and promote acute and chronic rejection after ITx. However, diagnostic criteria for ABMR after ITx have not been established yet and the mechanisms of antibody-mediated graft injury are not well-known. Effective approaches to prevent and treat ABMR are required to improve long-term outcomes of intestine recipients. Clearly, ABMR after ITx has become an important area for research and clinical investigation.

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.

Small bowel transplantation

BACKGROUND

Small bowel transplantation evolution, because of its complexity, was slower than other solid organs. Several advances have enabled its clinical application.

AIM

To review intestinal transplantation evolution and its current status.

METHOD

Search in MEDLINE and ScIELO literature. The terms used as descriptors were: intestinal failure, intestinal transplantation, small bowel transplantation, multivisceral transplantation. Were analyzed data on historical evolution, centers experience, indications, types of grafts, selection and organ procurement, postoperative management, complications and results.

CONCLUSION

Despite a slower evolution, intestinal transplantation is currently the standard therapy for patients with intestinal failure and life-threatening parenteral nutrition complications. It involves some modalities: small bowel transplantation, liver-intestinal transplantation, multivisceral transplantation and modified multivisceral transplantation. Currently, survival rate is similar to other solid organs. Most of the patients become free of parenteral nutrition.

Assessment and outcome of children with intestinal failure referred for intestinal transplantation

BACKGROUND & AIMS

Chronic intestinal failure (CIF) requires long term parenteral nutrition (PN) and, in some patients, intestinal transplantation (ITx). Indications and timing for ITx remain poorly defined. In the present study we aimed to analyze causes and outcome of children with CIF.

METHODS

118 consecutive patients referred to our institution were assessed by a multidisciplinary team and four different categories were defined retrospectively based on their clinical course: Group 1: patients with reversible intestinal failure; group 2: patients unsuitable for ITx, group 3: patients listed for ITx; group 4: patients stable under PN. Analysis involved comparison between groups for nutritional status, central venous catheter (CVC) related complications, liver disease, and outcome after transplantation by using non parametric tests, Mann-Whitney tests, Kruskal-Wallis, Wilcoxon signed rank tests and chi square distribution for percentage.

RESULTS

118 children (72 boys) with a median age of 15 months at referral (2 months-16 years) were assessed. Etiology of IF was short bowel syndrome [n = 47], intractable diarrhea of infancy [n = 37], total intestinal aganglionosis [n = 18], and chronic intestinal pseudoobstruction [n = 17]. Most patients (89.8%) were totally PN dependent, with 48 children (40.7%) on home-PN prior to admission. Nutritional status was poor with a median body weight at -1.5 z-score (ranges: -5 to +2.5) and median length at -2.0 z-score (ranges: -5.5 to +2.3). The mean number of CVC inserted per patient was 5.2 (range 1-20) and the mean number of CRS per patient was 5.5 (median: 5; range 0-12) Fifty-five patients (46.6%) had thrombosis of ≥2 main venous axis. At admission 34.7% of patients had elevated bilirubin (≥50 μmol/l), and 19.5% had platelets <100,000/ml, and 15% had both. Liver biopsy performed in 79 children was normal (n = 4), or showed F1 or F2 fibrosis (n = 29), bridging fibrosis F3 (n = 20), or cirrhosis (n = 26). Group 1 included 10 children finally weaned from PN (7-years survival: 100%). Group 2 included 12 children with severe liver disease and associated disorders unsuitable for transplantation (7-years survival: 16.6%). Group 3 included 66 patients (56%) who were listed for small bowel or liver-small bowel transplantation, 62/66 have been transplanted (7 years survival: 74.6%). Factors influencing outcome after liver-ITx were body weight (p < .004), length (p < .001), pre-Tx bilirubin plasma level (p < .001) and thrombosis (p < .01) for isolated ITx, Group 4 included 30 children (25.4%) with irreversible IF considered as potential candidates for isolated ITx. Four children were lost from follow up and 3 died within 2 years (survival 88.5%). Among potential candidates, the following parameters improved significantly during the first 12 months of follow up: Body weight (p.0001), length (p < .0001) and bilirubin (p < .0001).

CONCLUSIONS

many patients had a poor nutritional status with severe complications especially liver disease. PN related complications were the most relevant indication for ITx, but also a negative predictor for outcome. Early patient referral for Tx-assessment might help to identify and separate children with irreversible IF from children with transient IF or uncomplicated long-term PN, allowing to adapt a patient-based treatment strategy including or not ITx.

Mucosal changes induced by ischemia-reperfusion injury in a jejunal loop transplanted in oropharynx

Tissues exposed to ischemia and reperfusion develop an inflammatory response. We investigate the morphological and immunological changes occurring in the mucosa of a jejunal loop transplanted in the oropharynx of a man undergoing circular pharyngolaryngectomy. Jejunal biopsies were collected during the transplantation procedures (cold and warm ischemia, reperfusion), during the 7 post-operative days through an exteriorized jejunal segment for flap monitoring, and 45 days after transplantation through an upper endoscopy. Matrix metalloproteinase (MMP)-3 and MMP-12 increase was accompanied by a parallel rise in apoptotic enterocytes, and by a concomitant reduction of surface area to volume ratio and enterocyte height. Goblet cell hyperplasia is coupled with Paneth cell disappearance at the crypt base. CD8-positive intraepithelial lymphocytes initially decrease, then they increase in accordance with the peak of enterocyte apoptosis. We identified alterations in lymphocyte infiltration, mucosal architecture and epithelial cell turnover, which may give a window to mechanisms of small bowel ischemia-reperfusion in humans.

Survival of patients evaluated for intestinal and multivisceral transplantation - the Scandinavian experience

OBJECTIVE

The current treatment of choice for patients with intestinal failure is parenteral nutrition, whereas medical therapy or resection is preferred for patients with neuroendocrine pancreatic tumors (NEPT) along with liver metastasis. As the survival of patients undergoing intestinal and multivisceral transplantation is improving, the discussion for expansion of treatment options has become a subject of debate. The aim was to investigate the outcome for patients referred for intestinal and multivisceral transplantation and to determine which patient group are the ones most likely to benefit the most from transplantation.

METHODS

The authors included all patients evaluated for intestinal and multivisceral transplantation at the Sahlgrenska University Hospital and The Queen Silvia Children's Hospital center between February 1998 and November 2009. Patients were classified according to proposed treatment strategy, and the outcome was evaluated.

RESULTS

A total of 43 adults and 19 children with either intestinal failure or NEPT with liver metastases were evaluated for transplantation. Of these patients, 15 adults and 5 children were transplanted. Transplantation was lifesaving for most children - all the children survived after transplantation, but 70% (4/6) died while awaiting transplantation. Among the adult patients with intestinal failure, the survival rate for patients considered to be stable on parenteral nutrition was higher than the transplanted adult patients. The survival rate of patients with NEPT was similar to the results seen among patients transplanted for intestinal failure.

CONCLUSION

The results confirm the poor prognosis of patients with intestinal failure awaiting transplantation and indicate that different transplantation criteria may be applied for adults and children, especially when early transplantation is the preferred treatment. The role of multivisceral transplantation in patients with NEPT remains uncertain.

Implications for Interleukin-33 in solid organ transplantation

Interleukin(IL)-33 is a member of the IL-1 cytokine family that has been attributed T helper (Th) type 2 immunity-promoting capacity. However, new studies indicate that IL-33 is a multifunctional protein that acts as transcriptional/signaling repressor, functions as an alarmin alerting the immune system to necrosis, as well as serves as a cytokine that targets cells expressing ST2, the IL-33 receptor. Interestingly, IL-33 is also emerging as a pleiotropic cytokine. Depending on the innate or adaptive immune cells targeted by IL-33, it can not only promote type 2, but also IFN-γ dominated type 1 immunity. In addition, IL-33 expands regulatory T cells. In this review, we assimilate the current knowledge of IL-33 immunobiology and discuss how IL-33 may mediate such diverse roles in the immune response to pathogens and development of immune-mediated pathologies. The function of IL-33 in shaping alloimmune responses to transplanted organs is poorly explored, but a particularly beneficial role of IL-33 in experimental heart transplant models is summarized. Finally, given the implication of IL-33 in pathologies of the lung and intestine, we discuss how IL-33 may contribute to the comparatively poor outcomes following transplantation of these two organs.

Short bowel syndrome in the NICU

Short bowel syndrome (SBS) is the most common cause of intestinal failure in infants. In neonates and young infants, necrotizing enterocolitis, gastroschisis, intestinal atresia, and intestinal malrotation/volvulus are the leading causes of SBS. Following an acute postsurgical phase, the residual gastrointestinal tract adapts with reorganization of the crypt-villus histoarchitecture and functional changes in nutrient absorption and motility. A cohesive, multidisciplinary approach can allow most neonates with SBS to transition to full enteral feeds and achieve normal growth and development. In this article, the clinical features, management, complications, and prognostic factors in SBS are reviewed.

Epstein-Barr virus infection and posttransplant lymphoproliferative disorder

Epstein-Barr virus (EBV) is an important pathogen in recipients of solid organ transplants (SOT). Infection with EBV manifests as a spectrum of diseases/malignancies ranging from asymptomatic viremia through infectious mononucleosis to posttransplant lymphoproliferative disorder (PTLD). EBV disease and its associated PTLD is more frequently seen when primary EBV infection occurs after transplant, a common scenario in pediatric SOT recipients. Intensity of immunosuppressive therapies also influences the risk for PTLD. The use of EBV viral load monitoring facilitates the diagnosis and management of EBV/PTLD as well as being used to inform preemptive therapy with reduction of immunosuppression, the most effective intervention for prevention of and treatment for PTLD. Other therapies, including the rituximab (anti-CD20 monoclonal antibody) and traditional chemotherapy, are also useful in the treatment of established PTLD. The future development of standards for management based on EBV viral load and routine monitoring of EBV-specific CTL responses promise further improvement in outcomes with EBV and PTLD.

Short bowel syndrome in children: current and potential therapies

Short bowel syndrome (SBS) reflects a state of malabsorption that occurs due to loss of a significant portion of the small bowel. The pathophysiology of SBS is determined largely by the process of adaptation, which is the innate attempt by the remnant portions of the intestine to increase fluid and nutrient reabsorption. In recent years, emphasis has been placed on intestinal rehabilitation with multidisciplinary teams as a comprehensive approach to the management of patients with SBS. In our institution, the multidisciplinary team members include pediatric gastroenterologists, pediatric surgeons, pediatric dieticians, physical therapists, occupational therapists, neonatologists (especially for patients still under their care), transplant surgeons, transplant coordinators and social workers. Parenteral nutrition plays a significant role in the management of SBS, but its use is associated with many potential complications, including cholestatic liver disease. Fish oil-based lipid emulsions have shown promise in their ability to reverse and also prevent the development of cholestasis in these patients. Clinical trials have shown that growth factors and other trophic hormones facilitate the process of adaptation. The most significant impact has been shown with the use of glucagon-like peptide-2 and its analog (teduglutide). Surgical interventions remain an important part of the management of SBS to facilitate adaptation and treat complications. Intestinal transplantation is a last resort option when the process of adaptation is unsuccessful. This review article is intended to provide an overview of the conventional and emerging therapies for pediatric SBS.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.