Improvements in intestine transplantation

Survival Benefit of Solid-Organ Transplantation: 10-Year Update

IMPORTANCE

Transplantation has transformed into a burgeoning field that is rapidly evolving to optimize organ distribution and survival outcomes. The years since 2012 (the last comprehensive study) have seen changes in transplantation, such as advances in immunotherapy and novel indices, that necessitate an updated analysis of survival benefit.

DESIGN

Our goal was to determine the survival benefit for solid-organ transplants in the United Network for Organ Sharing (UNOS) database for a three decade period and provide updates on advancements since 2012. Our retrospective analysis examined data containing U.S. patient records from September 1, 1987, to September 1, 2021.

RESULTS

We found that 3,430,272 life-years were saved over our transplant period (4.33 life-years saved per patient); kidney-1,998,492 life-years; liver -767,414; heart-435,312; lung-116,625; pancreas-kidney-123,463; pancreas-30,575; intestine-7901. After matching, 3,296,851 life-years were saved. Life-years saved and median survival increased for all organs between 2012 and 2021. Compared to 2012, median survival increased in kidney (from 12.4 to 14.76 years), liver (from 11.6 to 14.59), heart (9.5 to 11.73), lung (5.2 to 5.63), pancreas-kidney (from 14.5 to 16.88), pancreas (from 13.3 to 16.10). When compared to 2012, the percent transplanted increased in kidney, liver, heart, lung, and intestine, while pancreas-kidney and pancreas show decreased percent transplanted.

CONCLUSION

Our study underscores the tremendous survival benefits of solid organ transplantation (over 3.4 million life-years saved) and shows improvements since 2012. Our study also highlights areas of transplantation, notably pancreas transplants, that may necessitate reinvigorated attention.

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.

Overview of Physical, Neurocognitive, and Psychosocial Outcomes in Pediatric Intestinal Failure and Transplantation

PURPOSE OF REVIEW

Intestinal failure and transplantation may significantly impact physical, neurocognitive, and psychosocial development in pediatric patients. Currently, there is a paucity of literature on the effects of intestinal failure and transplantation on these aspects of development. This article will review the current literature and discuss the short and long-term impacts as well as interventions to improve clinical outcomes in children with intestinal failure or those undergoing transplantation.

RECENT FINDINGS

Psychological disorders, neurodevelopmental delay, and social maladaptation are frequently encountered in this patient population. While the main focus is often on medical management, equal emphasis should be placed on other aspects of development such as increasing social support and improving school performance. The transition to adulthood also presents many obstacles for patients and healthcare providers should anticipate challenges such as childbirth, employment, and raising a family. The pre-operative, perioperative, and post-operative periods all represent opportunities for medical intervention. Frequent monitoring of physical, psychosocial, and neurocognitive status helps to improve clinical outcomes and long-term quality of life. Future research should emphasize continued development of multidisciplinary programs and specialized services to help address the physical and psychosocial needs of children with intestinal failure as well as transplant recipients.

Pediatric intestinal transplantation

Advancements in donor management, organ preservation and operative techniques, as well as immunosuppressive therapies, have provided children with intestinal failure and its complications a chance not only for enteral autonomy but also long-term survival through intestinal transplantation (ITx). First described in the 1960's, experience has grown in managing these complex patients both pre- and post-transplant. The goals of this review are to provide a brief history of intestinal transplantation and intestinal rehabilitation in pediatric patients, followed by focused discussions of the indications for ITx, induction and maintenance immunosuppression therapies, common post-operative complications, and outcomes/quality of life post-transplant.

Long-term outcomes of intestinal transplantation from donors aged under 1 year

BACKGROUND

The aim of the study was to analyze the long-term outcomes of transplants utilizing ITx donors <1 year and to compare these results with older donors.

METHODS

Between January 2007 and December 2019, the primary ITx donors in the Children's Hospital of Pittsburgh of UPMC were retrospectively reviewed. Short- and long-term outcomes of recipients receiving a deceased donor organ from donors <1 year were compared with those found in all other recipients.

RESULTS

During the study period, there were 89 primary ITx donors, using 30 donors (33.7%) aged <1 year. The mean age of their recipients was 1.6 ± 0.7 (0.7-3.2) years. The 30 graft types were isolated intestine (n = 3, 10.0%), liver bowel (n = 20, 66.7%), and multivisceral (n = 7, 23.3%). Technical complications occurred in 12 (40.0%) recipients. Candidates transplanted with intestine allografts from donors <1 year of age had shorter wait times (p < .001), more liver-inclusive grafts (p < .001), and less donor-specific antibodies (DSA) (p = .014). During follow-up, the recipients had less graft loss (p = .018), and more remained alive with graft in place (p = .011). Among children transplanted with such donors, 3-year and graft survival rates were 86.7% and 82.9% compared to 62.8% and 49.9% in the cohort of donors >1 year (p = .032 and .011).

CONCLUSIONS

Donor age <1 year was associated with improved graft survival. Optimal utilization of this population for toddler candidates would increase intestine availability, reduce time to transplantation, and potentially improve long-term outcome.

Grant monitoring after intestinal transplantation

PURPOSE OF REVIEW

The current review aims to describe in detail the most common practices utilized to monitor graft function in intestinal transplant (ITx) recipients. In addition, to discussing the role of endoscopy and stool studies it will examine the use of other potential biomarkers which have been utilized. Data will be discussed from contemporary publications in the field, the Intestinal Transplant Registry as well as detailed data from a large, ITx single-center.

RECENT FINDINGS

Significant improvements have been made in early outcomes following ITx, yet long-term survival remains challenged by infection and rejection, both of which can present with diarrhea. While endoscopy and stool studies are the gold-standard for graft monitoring, calprotectin, citrulline, measurements of immunoreactivity and donor-specific antibodies have been investigated in the field and are herein reviewed.

SUMMARY

Despite a number of tests which are currently available for monitoring ITx recipients, a strong need exists for improved noninvasive, timely and accurate biomarkers to help improve ITx graft and patient survival.

Current status of pediatric intestinal transplantation in the United States

PURPOSE OF REVIEW

The present review aims to describe in detail the characteristics, outcomes, and recent trends in the field of pediatric intestinal transplantation in the United States. It will examine the route cause and future implications of these developments. The review will draw from recent publications in the field, the Intestinal Transplant Registry, and contemporary data from large U.S. single centers.

RECENT FINDINGS

More than 1500 pediatric intestinal transplants have been performed in the United States since 1985, however, over the past decade there have been fewer than 50 transplants/year nationwide. This trend is largely a result of stagnant long-term ITx outcomes and advancements in intestinal rehabilitation programs. Nationally the overall 1-year and 5-year graft survival are 68 and 50% respectively, whereas certain high-volume centers have experienced significantly better results. Sepsis is the leading cause of death following pediatric ITx, whereas rejection is the leading cause of graft loss. Chronic kidney disease and posttransplant lymphoproliferative disorder are significant and relatively prevalent long-term complications. The majority of pediatric ITx recipients receive T-cell depleting induction agents and are on Tacrolimus-based immunosuppression. Most recipient are off parenteral nutrition, but may require supplemental tube feeds. Many pediatric ITx recipients require special education, and in certain domains some report lower health related quality of life.

SUMMARY

As intestinal rehabilitation has improved in the modern era, the volume of pediatric ITx in the United States has decreased. Although pediatric ITx results have room for improvement nationwide, successful outcomes have been reported at experienced American centers.

A detailed analysis of the current status of intestinal transplantation in the middle east

PURPOSE OF REVIEW

Intestinal transplantations are among the most complex transplantations, which are performed in few centers in the world. When patients develop intestinal failure, different treatment modalities including parenteral nutrition, autologous gastrointestinal tract reconstructive surgery, and intestinal transplantations are considered. The Middle East is a region where reports on intestinal failures and intestinal transplantations are mainly lacking. In the present review, we highlighted the status of intestinal transplantations in the Middle East and focused on existing reports from this region.

RECENT FINDINGS

Very few countries in the Middle East have the facilities for home parenteral nutrition and only two countries including Iran and Turkey perform intestinal transplantations in the region. With advances in intestinal rehabilitation units and development of autologous gastrointestinal tract reconstructive surgery, some centers have been able to reduce the number of patients in need of intestinal transplantations.

SUMMARY

An overview of the condition of intestinal transplantations in the Middle East shows that the issue of intestinal failure and the treatment facilities still remain an unsolved problem. Although there exists a high need for intestinal transplantation, advances in reconstructive surgeries and the development of parenteral nutrition in this region can significantly reduce the need for intestinal transplantations among patients with intestinal failure.

Bench to Bedside: Approaches for Engineered Intestine, Esophagus, and Colon

The generation of tissue engineered organs from autologous cells will allow replacement of diseased or absent organs without the need for immunosuppression. Common steps of tissue engineering include isolation of pluripotent or multipotent stem cells, preparation of synthetic or biologic scaffold, and implantation into a host to support the proliferation of engineered tissue. Some organs have been successfully transplanted in human patients; gastrointestinal tract tissues are nearing clinical introduction. The state of the science has progressed rapidly and providers and researchers alike must take appropriate steps to ensure strict adherence to ethical standards before introduction to human therapy.