OPTN/SRTR 2022 Annual Data Report: Pancreas.

The postpandemic recovery did not occur in pancreas transplantation as in other organs. The number of pancreas transplants in the United States decreased to 918 in 2022 from 963 in 2021. The number of simultaneous pancreas-kidney transplants decreased to 810 in 2022 from 820 in 2021, but the largest decrease was in pancreas transplant alone: 62 in 2022 compared with 92 in 2021. Pancreas-after-kidney transplants decreased to 46 in 2022 from 51 in 2021. The trend of increasing proportions of pancreas transplants in patients with type 2 diabetes seen over the past few years ended in 2022; there were 22.4% of such transplants in 2022 compared with 25.8% in 2021. The proportion of recipients older than 45 years decreased in 2022 as well. However, the proportions of candidates with type 2 diabetes and older candidates on the waiting list did not decrease. The number of pancreas donors decreased and the pancreas nonuse rate increased in 2022. Outcomes after pancreas transplant continued to improve, with an impressive 8.1% pancreas and 4.3% kidney graft failure rate for simultaneous pancreas-kidney transplant at 1 year in 2022. The proportion of pancreas transplants performed by medium-volume centers (11-24 transplants/year) returned to 37.2% in 2022 from a high of 48.3% in 2021, whereas the proportion of those done by large-volume centers (25 or more transplants/year) returned to 25.3% in 2022 from a low of 15.9% in 2021.

Banff 2022 pancreas transplantation multidisciplinary report: Refinement of guidelines for T cell-mediated rejection, antibody-mediated rejection and islet pathology. Assessment of duodenal cuff biopsies and noninvasive diagnostic methods.

The Banff pancreas working schema for diagnosis and grading of rejection is widely used for treatment guidance and risk stratification in centers that perform pancreas allograft biopsies. Since the last update, various studies have provided additional insight regarding the application of the schema and enhanced our understanding of additional clinicopathologic entities. This update aims to clarify terminology and lesion description for T cell-mediated and antibody-mediated allograft rejections, in both active and chronic forms. In addition, morphologic and immunohistochemical tools are described to help distinguish rejection from nonrejection pathologies. For the first time, a clinicopathologic approach to islet pathology in the early and late posttransplant periods is discussed. This update also includes a discussion and recommendations on the utilization of endoscopic duodenal donor cuff biopsies as surrogates for pancreas biopsies in various clinical settings. Finally, an analysis and recommendations on the use of donor-derived cell-free DNA for monitoring pancreas graft recipients are provided. This multidisciplinary effort assesses the current role of pancreas allograft biopsies and offers practical guidelines that can be helpful to pancreas transplant practitioners as well as experienced pathologists and pathologists in training.

Evolution of Pancreas Transplantation At A Single Institution-50+ Years and 2,500 Transplants.

OBJECTIVE: To describe the evolution of pancreas transplantation, including improved outcomes and factors associated with improved outcomes over the past five decades. BACKGROUND: The world's first successful pancreas transplant was performed in December 1966 at the University of Minnesota. As new modalities for diabetes treatment mature, we must carefully assess the current state of pancreas transplantation to determine its ongoing role in patient care. METHODS: A single-center retrospective review of 2,500 pancreas transplants performed over >50 years in bivariate and multivariable models. Transplants were divided into six eras; outcomes are presented for the entire cohort and by era. RESULTS: All measures of patient and graft survival improved progressively through the six transplant eras. The overall death censored (DC) pancreas graft half-lives were >35 years for simultaneous pancreas and kidney (SPK), 7.1 years for pancreas after kidney (PAK), and 3.3 years for pancreas transplants alone (PTA). The 10-year DC pancreas graft survival rate in the most recent era was 86.9% for SPK recipients, 58.2% for PAK recipients, and 47.6% for PTA. Overall graft loss was most influenced by patient survival in SPK transplants, whereas graft loss in PAK and PTA recipients was more often due to graft failures. Predictors of improved pancreas graft survival were primary transplants, bladder drainage of exocrine secretions, younger donor age, and shorter preservation time. CONCLUSIONS: Pancreas outcomes have significantly improved over time via sequential, but overlapping, advances in surgical technique, immunosuppressive protocols, reduced preservation time, and the more recent reduction of immune-mediated graft loss.

OPTN/SRTR 2021 Annual Data Report: Pancreas.

The number of pancreas transplants in the United States was largely unchanged in 2021 at 963 transplants compared with 962 in 2020, showing that recovery from the COVID-19 pandemic was not as pronounced in pancreas transplantation as in other organs. The number of simultaneous pancreas-kidney transplants (SPKs) decreased from 827 to 820, whereas the number of pancreas-after-kidney transplants and pancreas transplants alone increased marginally to compensate. The proportion of patients with type 2 diabetes on the waiting list increased to 22.9% in 2021, compared with 20.1% in 2020. Consequently, the proportion of transplants in patients with type 2 diabetes increased from 21.3% in 2020 to 25.9% in 2021. The proportion of transplants in older recipients (aged 55 years or older) also increased to 13.5% in 2021 from 11.7% in 2020. Outcomes after SPK continue to be the best of the three categories of pancreas transplants: 1-year graft failure for kidney at 5.7% and pancreas at 10.5% for transplants performed in 2020. The proportion of pancreas transplants performed by medium-volume centers (11-24 transplants per year) increased sharply to 48.3% in 2021 from 35.1% in 2020, with a corresponding decrease in transplants in large-volume centers (25 or more transplants per year) to 15.9% in 2021 from 25.7% in 2020.

The John S. Najarian symposium: The past, present, and future of surgery and transplantation, May 20, 2022, Minneapolis, MN.

Dr John S Najarian (1927-2020), chairman of the Department of Surgery at the University of Minnesota from 1967 to 1993, was a pioneer in surgery, clinical immunology and transplantation. A Covid-delayed Festschrift was held in his honor on May 20, 2022. The speakers reflected on his myriad contributions to surgery, transplantation, and resident/fellow training, as well as current areas of ongoing research to improve clinical outcomes. Of note, Dr Najarian was a founder of the journal Clinical Transplantation.

Effective treatment of diabetes, improved quality of life and accelerated cognitive development after pancreas transplantation in a child with type 1 diabetes and allergy to manufactured insulin preparations.

BACKGROUND: Insulin hypersensitivity reactions are rare but serious and significantly affect the treatment of diabetes in children. METHODS: A 13-year-old girl with type 1 diabetes, hypoglycemic unawareness, and treatment refractory allergy to available insulin preparations underwent a solitary pancreas transplant. Before the pancreas transplantation, she was receiving a continuous subcutaneous infusion of rapid-acting insulin with an increasing need for antihistamines and steroids, negatively impacting her cognitive and social development. Her diabetes was poorly controlled, and her quality of life was progressively worsening. RESULTS: Following the transplant, she recovered well from surgery and achieved euglycemia without needing exogenous insulin. She had two biopsy proven episodes of acute cellular rejection, successfully treated. Her cognitive development also accelerated. Notable improvement was noted both in her personal quality of life and her family's overall well-being. CONCLUSIONS: This is the youngest pancreas transplant recipient with over 1-year graft survival reported in the literature. Pancreas transplant alone in a teenager without indications for kidney transplantation could be considered a last resort treatment for diabetes when continuing insulin therapy presents a high level of morbidity. A pancreas transplant is a feasible treatment modality for patients with refractory insulin allergy.

First world consensus conference on pancreas transplantation: Part I-Methods and results of literature search.

Comprehensive evidence-based guidelines for the practice of pancreas transplantation are yet to be established. The First World Consensus Conference on Pancreas Transplantation was convened for this purpose. A steering committee selected the participants and defined the questions to be addressed. A group of literature reviewers identified 597 studies to be included in summaries for guidelines production. Expert groups formulated the first draft of recommendations. Two rounds of discussion and voting occurred online, using the Delphi method (agreement rate ≥85%). After each round, critical responses of experts were reviewed, and recommendations were amended accordingly. Recommendations were finalized after live discussions. Each session was preceded by expert presentations and a summary of results of systematic literature review. Up to three voting rounds were allowed for each recommendation. To avoid potential conflicts of interest, deliberations on issues regarding the impact of pancreas transplantation on the management of diabetes were conducted by an independent jury. Recommendations on technical issues were determined by experts and validated using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. Quality of evidence was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) methodology. Each recommendation received a GRADE rating (Grading of Recommendations, Assessment, Development and Evaluations).

The demise of islet allotransplantation in the United States: A call for an urgent regulatory update.

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.

Survival benefit of the homologous kidney allograft in simultaneous pancreas-kidney transplants and its potential protective role.

The superior death-censored graft survival of the pancreas allograft in simultaneous pancreas kidney transplants (SPK) over pancreas alone transplants (PTA) has long been recognized. Using data from the Scientific Registry of Transplant Recipients (SRTR) and a high-volume pancreas transplant program, we investigated the possible protective role of the kidney allograft in SPK transplants. We analyzed 19 043 primary pancreas transplants between 2000 and 2020, including 735 transplants performed at the University of Minnesota. SPK transplants demonstrated a superior death-censored graft survival over pancreas after kidney (PAK) and simultaneous pancreas and living donor kidney (SPLK) transplants, which both demonstrated better survival than PTA transplants. This effect was not affected by mode or duration of renal replacement therapy prior to transplant. Furthermore, we found that HLA match at the B-locus between the prior kidney and current pancreas allografts demonstrated a protective effect (HR .54; 95% confidence interval .29-1.00), with a 2-antigen match demonstrating superior death-censored graft survival to a 1- or 0-antigen match. We propose that a homologous kidney allograft in SPK transplants affords protection to the pancreas allograft-likely through a combination of better surveillance for rejection and direct immunoprotection offered by the same-donor kidney.

Best practice recommendations for the use of hepatitis C viremic donor organs for hepatitis C virus naïve recipients.

The combination of the transplant organ deficit, the increase in HCV nucleic acid positive donors (HCV NAT+), and the development of direct-acting antiviral agents (DAAs) has resulted in a rapid increase in HCV NAT+ organ transplants into HCV naïve recipients. Early clinical experience with HCV NAT+ donor organs has shown promising outcomes; however, best practices are lacking to guide transplant programs during all phases of patient care. Transplant programs developing protocols for the utilization of HCV NAT+ organs will need a multidisciplinary team to address all aspects of pre-transplant and post-transplant patient care. Reports of fibrosing cholestatic hepatitis in HCV NAT+ organ transplant recipients receiving delayed DAA initiation highlight the need for the transplant community to develop safe and effective protocols. A failure to do so will inevitably lead to the erosion of public trust from cases of missed or inadequately treated donor-derived HCV infections. Herein, we provide best practice guidelines for the utilization of HCV NAT+ organs into HCV-negative recipients based on literature review and expert opinion from the faculty of the ASTS Standards and Quality Committee.

Improving safety in organ recovery transportation: Report from the ASTS/UNOS/AST/AOPO transportation safety summit.

Despite the passage of a decade since the tragic loss of an organ recovery team from the University of Michigan, there are currently no national standards governing air and ground transportation of organ recovery personnel. Consequently, the American Society of Transplant Surgeons, the Association of Organ Procurement Organizations, and the United Network for Organ Sharing jointly convened a transportation summit to review and update recommendations for national transportation standards. Expanded air transport quality assurance protocols, including a requirement for two engine turbine-powered aircraft piloted by two qualified pilots certified through onsite inspections was recommended. Ground transportation providers must ensure adequate safety restraints are available, ambulance avoided if possible, and the use of lights and sirens minimized. Finally, adequate insurance coverage for all team members, including trainees should be provided and should not rely on carrier liability insurance policies. The summit participants have committed the support of their organizations to promote and enact these regulations nationally.

Predictors of Survival After Liver Transplantation in Patients With the Highest Acuity (MELD ≥40).

OBJECTIVE: To identify factors that accurately predict 1-year survival for liver transplant recipients with a MELD score ≥40. BACKGROUND: Although transplant is beneficial for patients with the highest acuity (MELD ≥40), mortality in this group is high. Predicting which patients are likely to survive for >1 year would be medically and economically helpful. METHODS: The Scientific Registry of Transplant Recipients database was reviewed to identify adult liver transplant recipients from 2002 through 2016 with MELD score ≥40 at transplant. The relationships between 44 recipient and donor factors and 1-year patient survival were examined using random survival forests methods. Variable importance measures were used to identify the factors with the strongest influence on survival, and partial dependence plots were used to determine the dependence of survival on the target variable while adjusting for all other variables. RESULTS: We identified 5309 liver transplants that met our criteria. The overall 1-year survival of high-acuity patients improved from 69% in 2001 to 87% in 2016. The strongest predictors of death within 1 year of transplant were patient on mechanical ventilator before transplantation, prior liver transplant, older recipient age, older donor age, donation after cardiac death, and longer cold ischemia. CONCLUSIONS: Liver transplant outcomes continue to improve even for patients with high medical acuity. Applying ensemble learning methods to recipient and donor factors available before transplant can predict survival probabilities for future transplant cases. This information can be used to facilitate donor/recipient matching and to improve informed consent.

A call to action: Feasible strategies to reduce the discard of transplantable kidneys in the United States.

Changes to the United States kidney allocation system targeted at reducing organ discard have failed to improve organ utilization. High Kidney Donor Profile Index kidneys continue to be discarded at high rates as a result of the regulatory and financial barriers to widespread utilization of these organs. However, there are potential changes to clinical practice that could improve organ utilization. Expediting the time from initial offer to final organ acceptance would reduce cold ischemic time and should improve utilization. Implementation of procurement biopsy standards to avoid biopsy of low risk organs may prevent organ discards due to inaccurate data or excessive cold ischemia time. Further, standardization of procurement biopsy pathological interpretation coupled with electronic accessibility would enable early acceptance of difficult to transplant organs. These changes to allocation practice patterns are vital given proposals to expand the geographic sharing of deceased donor kidneys. Implementation of new allocation policies must be evaluated to ensure they result in higher transplant rates and acceptable post-transplant outcomes.

Long-Term Infectious and Noninfectious Outcomes of Monthly Alemtuzumab as a Calcineurin Inhibitor- and Steroid-Free Regimen for Pancreas Transplant Recipients.

Multiple doses of alemtuzumab for immunosuppressive therapy of patients with hematologic malignancies and hematopoietic stem cell transplant have been associated with a high rate of infection. In transplantation, limited alemtuzumab dosing has been successfully used as induction immunosuppression. The effect of multiple doses of alemtuzumab, used as maintenance therapy to minimize steroid and/or calcineurin inhibitor toxicity in solid organ transplant recipients, is unknown. We evaluated the infectious and noninfectious outcomes of 179 pancreas transplant recipients treated with alemtuzumab for induction and maintenance therapy (extended alemtuzumab exposure (EAE)) from 2/28/2003 through 8/31/2005, compared with 159 pancreas transplant recipients with standard induction and maintenance (SIM) therapy performed before (1/1/2002 until 12/31/2002) and after (1/1/2006 until 12/31/2006) the implementation of EAE. EAE was associated with higher risk of overall infections (hazard ratio (HR) 1.33 (1.06-1.66), P=0.01), bacterial infections (HR 1.33 (1.05-1.67), P=0.02), fungal infections (HR 1.86 (1.28-2.71), P < 0.01), and cytomegalovirus infections (HR 2.29 (1.39-3.77), P < 0.01). In addition, EAE was associated with higher risk of acute cellular rejection (HR 2.09 (1.46-2.99), P < 0.01). In conclusion, while a limited alemtuzumab dosing is safe and effective for induction therapy in pancreas transplantation, EAE combined with steroid and calcineurin minimization is associated with a high risk of infectious complications and acute cellular rejection.

Influence of the procurement surgeon on transplanted abdominal organ outcomes: An SRTR analysis to evaluate regional organ procurement collaboration.

Single-center studies have demonstrated regional organ procurement collaboration to reduce travel redundancy and improve procurement efficiency. We studied deceased donor kidney, liver, and pancreas transplants performed in the United States between 2002 and 2014 using the Scientific Registry of Transplant Recipients (SRTR). We compared graft failure (GF), death-censored graft failure (DCGF), and patient death (PD) between organs procured by surgeons from the recipient's center (transplant procurement team [TPT]) versus surgeons from a different center (NTPT). Primary nonfunction (PNF) was assessed for liver and kidney and delayed graft function (DGF) for kidney using mixed-effects logistic modeling. There were 64 906 liver (61.6% TPT), 118 152 kidney (26.1% TPT), 10 832 simultaneous pancreas kidney (SPK; 56.6% TPT), and 4378 solitary pancreas (SP; 34.0% TPT) transplants. When compared to NTPT, DCGF for organs procured by TPT was significantly less for liver (adjusted HR: 0.93; 95% CI: 0.88-0.98) and marginally significant for kidney (0.97; 0.93-1.00) and SPK (0.90; 0.82-1.00), and not significant for SP (0.98; 0.86 -1.11). DGF for TPT kidney was significantly lower (adjusted OR 0.91; 0.87-0.95). Albeit modest, our findings demonstrate a difference between locally procured organs and those procured by the implanting team. Elucidating the etiology of these differences will enhance regional organ procurement collaboration.

Delivery of transplant care among Hmong kidney transplant recipients: Outcomes from a single institution.

Kidney transplantation entails well-coordinated complex care delivery. Patient-provider cultural and linguistic discordance can lead to healthcare disparities. We analyzed kidney transplantation outcomes among our institution's Hmong recipients using a retrospective cohort study. From 1995 to 2015, 2164 adult (age ≥18) recipients underwent kidney transplantation at our institution; 78 self-identified as Hmong. Survival rates were analyzed and compared to Caucasian recipients (n = 2086). Fifty (64.1%) Hmong recipients consistently requested interpreters. Mean follow-up was 9.8 years for both groups. Hmong recipients (N = 78) were on average younger at transplant (45.7 vs 49.7 years; P = 0.02), more likely to be female (56% vs 38%; P = 0.001), and had higher gravidity (5.0 vs 1.9 births; P < 0.001). There were 13 (16.7%) Hmong living donor recipients, who were younger (32.8 vs 42.9 years; P = 0.006) at transplant compared to Caucasians (1429, 68.5%). Hmong 1- and 5-year patient survival was 100%; Caucasians, 97.1% and 88% (P < 0.001). Hmong 1- and 5-year graft survival was 98.7% and 84.9%; Caucasians 94.8% and 80.9% (P = 0.013). One- and 5-year rejection-free survival showed no difference (88.9% vs 82.4%; 86.7% vs 83.4%, P = 0.996). Despite cultural and linguistic differences between Hmong recipients and providers, we found no evidence of inferiority in KT outcomes in the Hmong population.

The liver recipient with acute renal dysfunction: A single institution evaluation of the simultaneous liver-kidney transplant candidate.

The Organ Procurement Transplant Network (OPTN) listing criteria for simultaneous liver-kidney transplant (SLK) are not well defined. Concerns remain about rising numbers of SLKs, which divert quality kidneys from candidates awaiting kidney transplants (KT). We performed a retrospective review of liver transplants (LTs) at our center from 2004 to 2014; 127 recipients (liver transplant alone; 102 LTA, 25 SLK) were identified with short-term preoperative kidney dysfunction (creatinine >4 mg/dL or preoperative hemodialysis [HD] for <6 weeks). Both cohorts had comparable baseline demographic characteristics with the exception of higher model for end-stage liver disease (MELD) score in the LTA group (41.4 vs 32.9, P < .0001) and higher incidence of pre-LT diabetes in the SLK cohort (52% vs 26.5%, P = .0176). Duration of pre-LT HD was higher in SLK recipients, but the difference was not statistically significant (P = .39). Renal nonrecovery (RNR) rate in LTA cohort was low (<5%). No significant difference was noted in 1-year mortality, liver graft rejection/failure, or length of stay (LOS) between the cohorts. Thus, it appears that liver recipients with short-term (<6 weeks) HD or AKI without HD have comparable outcomes between LTA and SLK. With provisions for a KT safety net, as proposed by OPTN, LTA may be the most adequate option for these patients.

Age alone is not a contraindication to kidney donation: Outcomes of donor nephrectomy in the elderly.

With increasing organ demand, living kidney donation from older donors (>60-years-old) has become more common. Between 1975 and 2014, 3752 donor nephrectomies (DN) were performed at University of Minnesota; 167 (4.5%) were >60-years-old Short- and long-term outcomes were compared between contemporaneous >60-years-old and <60-years-old donors. On univariate analysis, >60-years-old were more likely to have had prior abdominal surgery and hypertension; and less likely to smoke. Baseline estimated glomerular filtration rate (eGFR) was lower in >60-years-old (80 ± 16 vs 101 ± 26 mL/min/1.73 m2 ; P < .001). Intraoperative and postoperative complications were similar, except a higher prevalence of <30 day ileus (3% vs 7%; P = .021) and longer postoperative length of stay (LOS) (4.2 vs 4.6 days; P = .005). On multivariate analysis, <30 day ileus and LOS continued to be significantly greater for >60-years-old After >20 years post-DN, systolic blood pressure was significantly higher among >60-years-old (142 vs 125 mm Hg; P < .001) and HTN was diagnosed earlier (9 vs 14 years). After donation, eGFR was significantly lower for >60-years-old but slope of eGFR and rates of end-stage renal disease (ESRD) were not significantly different >20 years post-DN. Thus, kidney donation among carefully selected >60-years-old poses minimal perioperative risks and no added risk of long-term ESRD.

Outcomes of Endovascular Management of Late Vascular Hemorrhage After Pancreatic Transplant.

OBJECTIVE: The aim of this retrospective study is to evaluate the endovascular treatment of hemorrhage in the nonperioperative setting in pancreas transplant recipients. MATERIALS AND METHODS: All angiograms performed between January 1, 1999, and June 1, 2016, to treat hemorrhage after pancreatic transplant at a single large-volume transplant center were reviewed. Fourteen patients who underwent 21 angiograms were identified. The patients' charts were reviewed for clinical indications, technical aspects of the endovascular interventions, outcomes, and complications. RESULTS: The mean number of angiograms was 1.5 per patient. The primary and primary assisted clinical success rates were 64.3% (9/14 patients) and 71.4% (10/14 patients), respectively. Five patients (35.7%) experienced complications. At presentation, eight patients had functioning grafts and seven of these eight patients (87.5%) maintained graft function. CONCLUSION: It is critical to recognize transplant-related hemorrhage after pancreas transplant. Endovascular management is associated with high clinical success and rarely results in loss of graft function, suggesting that it should be a consideration for first-line therapy in this patient population.

Defining outcomes for ß-cell replacement therapy in the treatment of diabetes: a consensus report on the Igls criteria from the IPITA/EPITA opinion leaders workshop.

ß-cell replacement therapy, available currently as pancreas or islet transplantation, has developed without a clear definition of graft functional and clinical outcomes. The International Pancreas & Islet Transplant Association (IPITA) and European Pancreas & Islet Transplantation Association (EPITA) held a workshop to develop consensus for an IPITA/EPITA Statement on the definition of function and failure of current and future forms of ß-cell replacement therapy. There was consensus that ß-cell replacement therapy could be considered as a treatment for ß-cell failure, regardless of etiology and without requiring undetectable C-peptide, accompanied by glycemic instability with either problematic hypoglycemia or hyperglycemia. Glycemic control should be assessed at a minimum by glycated hemoglobin (HbA1c ) and the occurrence of severe hypoglycemia. Optimal ß-cell graft function is defined by near-normal glycemic control [HbA1c  ≤ 6.5% (48 mmol/mol)] without severe hypoglycemia or requirement for insulin or other antihyperglycemic therapy, and with an increase over pretransplant measurement of C-peptide. Good ß-cell graft function requires HbA1c  < 7.0% (53 mmol/mol) without severe hypoglycemia and with a significant (>50%) reduction in insulin requirements and restoration of clinically significant C-peptide production. Marginal ß-cell graft function is defined by failure to achieve HbA1c  < 7.0% (53 mmol/mol), the occurrence of any severe hypoglycemia, or less than 50% reduction in insulin requirements when there is restoration of clinically significant C-peptide production documented by improvement in hypoglycemia awareness/severity, or glycemic variability/lability. A failed ß-cell graft is defined by the absence of any evidence for clinically significant C-peptide production. Optimal and good functional outcomes are considered successful clinical outcomes.