OPTN/SRTR 2011 Annual Data Report: intestine

Development and validation of a novel nomogram model for predicting delayed graft function in deceased donor kidney transplantation based on pre-transplant biopsies

BACKGROUND

Delayed graft function (DGF) is an important complication after kidney transplantation surgery. The present study aimed to develop and validate a nomogram for preoperative prediction of DGF on the basis of clinical and histological risk factors.

METHODS

The prediction model was constructed in a development cohort comprising 492 kidney transplant recipients from May 2018 to December 2019. Data regarding donor and recipient characteristics, pre-transplantation biopsy results, and machine perfusion parameters were collected, and univariate analysis was performed. The least absolute shrinkage and selection operator regression model was used for variable selection. The prediction model was developed by multivariate logistic regression analysis and presented as a nomogram. An external validation cohort comprising 105 transplantation cases from January 2020 to April 2020 was included in the analysis.

RESULTS

266 donors were included in the development cohort, 458 kidneys (93.1%) were preserved by hypothermic machine perfusion (HMP), 96 (19.51%) of 492 recipients developed DGF. Twenty-eight variables measured before transplantation surgery were included in the LASSO regression model. The nomogram consisted of 12 variables from donor characteristics, pre-transplantation biopsy results and machine perfusion parameters. Internal and external validation showed good discrimination and calibration of the nomogram, with Area Under Curve (AUC) 0.83 (95%CI, 0.78-0.88) and 0.87 (95%CI, 0.80-0.94). Decision curve analysis demonstrated that the nomogram was clinically useful.

CONCLUSION

A DGF predicting nomogram was developed that incorporated donor characteristics, pre-transplantation biopsy results, and machine perfusion parameters. This nomogram can be conveniently used for preoperative individualized prediction of DGF in kidney transplant recipients.

Intestinal Rehabilitation Programs in the Management of Pediatric Intestinal Failure and Short Bowel Syndrome

Intestinal failure is a rare, debilitating condition that presents both acute and chronic medical management challenges. The condition is incompatible with life in the absence of the safe application of specialized and individualized medical therapy that includes surgery, medical equipment, nutritional products, and standard nursing care. Intestinal rehabilitation programs are best suited to provide such complex care with the goal of achieving enteral autonomy and oral feeding with or without intestinal transplantation. These programs almost all include pediatric surgeons, pediatric gastroenterologists, specialized nurses, and dietitians; many also include a variety of other medical and allied medical specialists. Intestinal rehabilitation programs provide integrated interdisciplinary care, more discussion of patient management by involved specialists, continuity of care through various treatment interventions, close follow-up of outpatients, improved patient and family education, earlier treatment of complications, and learning from the accumulated patient databases. Quality assurance and research collaboration among centers are also goals of many of these programs. The combined and coordinated talents and skills of multiple types of health care practitioners have the potential to ameliorate the impact of intestinal failure and improve health outcomes and quality of life.

Intestine Transplantation Across a Positive Crossmatch With Preformed Donor-Specific Antibodies

BACKGROUND

We describe our experience using a modified protocol for immunosuppression for intestine transplantation across a positive crossmatch. Patients who underwent transplantation in 2013 were evaluated over a 12-month period for rejection and infectious events with comparison to procedure-matched controls on our standard protocol of immunosuppression.

PATIENTS AND METHODS

We used a modified protocol for intestine and multivisceral transplantation for patients with a positive flow crossmatch. In addition to our standard protocol, patients with positive crossmatch were given rituximab and intravenous immunoglobulin (IVIg) preoperatively. DSA was sent for clinical evaluation at monthly intervals. Patients were screened for rejection by endoscopic evaluation.

RESULTS

Four patients underwent transplantation within a single year across a positive crossmatch. Two received isolated intestine transplants and 2 had multivisceral transplantation (MVT). During the 12-month follow-up, 1 patients had an episode of severe acute cellular rejection, which was managed with increased immunosuppression. None of the patients had episodes of cytomegalovirus infection. One patient developed major infection and 3 patients developed minor bacterial infections. Among procedure-matched controls with negative final crossmatch on standard management (no preoperative rituximab or IVIg), 2 developed mild acute cellular rejection and 2 developed minor infections. One developed cytomegalovirus viremia with invasion to the colonic mucosa.

CONCLUSIONS

We report our protocol for immunosuppression for IT and MVT across a positive crossmatch. This allowed transplantation despite the presence of a positive crossmatch, with low rejection rates but potentially increased risk for major infections compared to the negative crossmatch controls on our standard protocol.

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.

Mortality and Rates of Graft Rejection or Failure Following Intestinal Transplantation in Patients With vs Without Crohn's Disease

BACKGROUND & AIMS

Treatment of Crohn's disease (CD) may require multiple bowel resections that lead to short bowel syndrome. Intestinal transplantation is an effective treatment for short bowel syndrome, but limited data are available on long-term outcomes in CD. We aimed to characterize the long-term risk of rejection, graft failure, and death among patients with CD after intestinal transplantation, and compare their outcomes with those of patients without CD.

METHODS

We performed a retrospective study of adults in the Scientific Registry of Transplant Recipients who received intestinal transplants in the United States from May 1990 through June 2014. Outcomes data were collected at 3 months, 6 months, 1 year, and every year after the procedure. We compared risks of rejection at 1 year after transplantation between patients with and without CD using the chi-square test and logistic regression. Longitudinal risks of graft failure and death were compared between patients with and without CD using the Kaplan-Meier method and Cox proportional hazards. Multivariable analyses adjusted for recipient, donor, and institutional characteristics.

RESULTS

Of 1115 cases of intestinal transplantation, 142 were performed for CD and 973 for non-CD indications. One year after the procedure, the transplant was rejected in 36.9% of patients with CD and 33.3% of patients without CD (P = .48). For patients with CD, the actuarial risk of graft failure at 1, 5, and 10 years after intestinal transplantation was 18.6%, 38.7%, and 49.2%; the risk of death was 22.5%, 50.3%, and 59.7%, respectively. The risk of graft failure was greater for patients with CD (adjusted hazard ratio [aHR], 1.48; 95% CI, 1.03-2.13; P = .04), but patients with versus without CD had similar risks of death (aHR, 0.88; 95% CI, 0.64-1.20; P = .41). In subgroup analyses, the risk of graft failure was increased among patients with CD undergoing transplantation between 1990 and 2000 (aHR, 3.49; 95% CI, 1.23-9.92; P = .02), but not after 2000 (aHR, 1.37; 95% CI, 0.92-2.04; P = .12).

CONCLUSIONS

In an analysis of patients who received intestinal transplants, the risks of graft rejection or death were similar between patients with versus without CD. Before year 2000, patients with CD had an increased risk of graft failure, but not thereafter. Changes in posttransplant immunosuppression around the same time might be analyzed to learn more about the mechanisms and management strategies to reduce graft failure in CD.

The use of renal replacement therapy in critically ill pediatric small bowel transplantation candidates and recipients: Experience from one center

Outcomes for pediatric SBT patients requiring perioperative RRT in the PICU remain unknown. The objectives were to document our center's experience with PICU SBT patients receiving perioperative RRT and to identify variables predictive of survival to discharge. A retrospective chart review of patients (ages, 0-18 yr) between January 1, 2000 and December 31, 2011 that received RRT within a SBT perioperative period and were transplanted at our university-affiliated, tertiary care children's hospital was performed. Six SBT patients received perioperative RRT (ages, 5-12 yr). Three patients (50%) survived to hospital discharge. Among survivors, RRT was required for a total of 1-112 days (mean, 49.7 days). All three survivors survived to hospital discharge without renal transplantation and free of RRT. There was a trend toward increased survival among older patients receiving RRT (p = 0.05). Survivors had a higher I-125 GFR prior to PICU admission (p = 0.045). A higher I-125 GFR prior to PICU admission among survivors may support this test's utility during SBT evaluation. In our experience, a high survival rate and freedom from RRT at the time of discharge support RRT use in the SBT population.

Cost-effectiveness of intestinal transplantation for adult patients with intestinal failure: a simulation study

BACKGROUND

Home parenteral nutrition (HPN) and intestinal transplantation (ITx) are the 2 treatment options for irreversible intestinal failure (IF).

OBJECTIVE

This study simulated the disease course of irreversible IF and both of these treatments--HPN and ITx--to estimate the cost-effectiveness of ITx.

DESIGN

We simulated IF treatment in adults as a discrete event model with variables derived from the Dutch Registry of Intestinal Failure and Intestinal Transplantation, the Intestinal Transplant Registry, hospital records, the literature, and expert opinions. Simulated patients were enrolled at a rate of 40/mo for 10 y. The maximum follow-up was 40 y. Survival was simulated as a probabilistic function. ITx was offered to 10% of patients with <12 mo of remaining life expectancy with HPN if they did not undergo ITx. Costs were calculated according to Dutch guidelines, with discounting. We evaluated the cost-effectiveness of ITx by comparing models conducted with and without ITx and by calculating the cost difference per life-year gained [incremental cost-effectiveness ratio (ICER)].

RESULTS

The average survival was 14.6 y without ITx and 14.9 y with ITx. HPN costs were €13,276 for treatment introduction, followed by €77,652 annually. The costs of ITx were ∼€73,000 during the first year and then €13,000 annually. The ICER was €19,529 per life-year gained.

CONCLUSION

Our simulations show that ITx slightly improves survival of patients with IF in comparison with HPN at an additional cost of €19,529 per life-year gained.

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

Intestinal Transplantation from Living Donors

Intestinal transplantation (ITx) represents the physiologic alternative to total parenteral nutrition (TPN) for patients suffering from life-threatening complications of irreversible intestinal failure. The number of transplants performed worldwide has been increasing for several years until recently. ITx has recently become a valid therapeutic option with a graft survival rate between 80 % and 90 % at 1 year, in experienced centers. These results have been achieved due to a combination of several factors: better understanding of the pathophysiology of intestinal graft, improved immunosuppression techniques, more efficient strategies for the monitoring of the bowel graft, as well as control of infectious complications and posttransplant lymphoproliferative disease (PTLD). In fact, this procedure is associated with a relatively high rate of complications, such as infections, acute rejection, graft versus host disease (GVHD), and PTLD, if compared to the transplantation of other organs. These complications may be, at least in part, the consequence of the peculiarity of this graft, which contains gut-associated lymphoid tissue and potentially pathogenic enteric flora. Furthermore, in these patients, the existing disease and the relative malnutrition could predispose them to infectious complications. Additionally, other factors associated with the procedure, such as laparotomy, preservation injury, abnormal motility, and lymphatic disruption, could all be implicated in the development of complications.

Cannabinoids inhibit T-cells via cannabinoid receptor 2 in an in vitro assay for graft rejection, the mixed lymphocyte reaction

Cannabinoids are known to have anti-inflammatory and immunomodulatory properties. Cannabinoid receptor 2 (CB2) is expressed mainly on leukocytes and is the receptor implicated in mediating many of the effects of cannabinoids on immune processes. This study tested the capacity of Δ(9)-tetrahydrocannabinol (Δ(9)-THC) and of two CB2-selective agonists to inhibit the murine Mixed Lymphocyte Reaction (MLR), an in vitro correlate of graft rejection following skin and organ transplantation. Both CB2-selective agonists and Δ(9)-THC significantly suppressed the MLR in a dose dependent fashion. The inhibition was via CB2, as suppression could be blocked by pretreatment with a CB2-selective antagonist, but not by a CB1 antagonist, and none of the compounds suppressed the MLR when splenocytes from CB2 deficient mice were used. The CB2 agonists were shown to act directly on T-cells, as exposure of CD3(+) cells to these compounds completely inhibited their action in a reconstituted MLR. Further, the CB2-selective agonists completely inhibited proliferation of purified T-cells activated by anti-CD3 and anti-CD28 antibodies. T-cell function was decreased by the CB2 agonists, as an ELISA of MLR culture supernatants revealed IL-2 release was significantly decreased in the cannabinoid treated cells. Together, these data support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients.

Successful rehabilitation in pediatric ultrashort small bowel syndrome

OBJECTIVE

To examine treatment outcomes in pediatric patients with ultrashort small bowel (USSB) syndrome in an intestinal rehabilitation program (IRP).

STUDY DESIGN

We reviewed IRP records for 2001-2011 and identified 28 children with USSB (≤ 20 cm of small bowel). We performed univariate analysis using the Fisher exact test and Wilcoxon rank-sum test to compare characteristics of children who achieved parenteral nutrition (PN) independence with intact native bowel and those who did not. Growth, nutritional status, and hepatic laboratory test results were compared from the time of enrollment to the most recent values using the Wilcoxon signed-rank test.

RESULTS

Of the 28 patients identified, 27 (96%) survived. Almost one-half (48%) of these survivors achieved PN independence with their native bowel. The successfully rehabilitated patients were more likely to have an intact colon and ileocecal valve (P = .01). Significant improvements in PN kcal/kg, total bilirubin, and height and weight z-scores were seen in all patients, but serum hepatic transaminase levels did not improve in the nonrehabilitated patients.

CONCLUSION

Enrollment in an IRP provides an excellent probability of survival for children with USSB. The presence of an intact ileocecal valve and colon are positively associated with rehabilitation in this population, but are not requisite. Approximately one-half of patients with USSB can achieve rehabilitation, with a median time to PN independence of less than 2 years. The USSB population can attain reduced PN dependence, improvement of PN-associated liver disease, and enhanced growth with the aid of an IRP.