The survival advantage of pancreas after kidney transplant

New onset diabetic ketoacidosis in a renal transplant recipient

Post-transplant diabetes mellitus (PTDM) is a well-known solid organ transplant complication, which can be related to immunosuppressants, particularly tacrolimus. We report an unusual presentation of PTDM with diabetic ketoacidosis (DKA). This is unique as PTDM typically resembles Type 2 DM, whereas DKA is associated with Type 1 DM and has rarely been reported as a complication of tacrolimus. A 38-year-old African American male on LCP-tacrolimus presented four months post kidney transplant with vomiting, weakness, poor appetite, and polyuria. Labs demonstrated hyperglycemia, ketonuria, and high anion gap metabolic acidosis. He was nonobese and had no personal or family history of Type 2 DM. DKA was suspected to be secondary to tacrolimus-induced pancreatic beta cell damage worsened by supratherapeutic tacrolimus levels. Latent autoimmune diabetes in adults (LADA) was diagnosed when further testing showed insulinopenia, low C-peptide, and anti-glutamic acid decarboxylase (GAD) autoantibodies. He required 120-units of subcutaneous insulin daily. Our literature review revealed only 16 other tacrolimus-induced DKA cases. No cases reported anti-GAD positivity and most showed beta cell toxicity reversibility with tacrolimus tapering or substitution. Our patient was early post-transplant with leukocytopenia, so tacrolimus was not exchanged. This unusual PTDM case may have resulted from both autoimmune and tacrolimus-induced beta cell destruction. Physicians should be aware of new onset LADA post-transplantation and tacrolimus toxicity leading to DKA, even in patients without traditional risk factors. Anti-GAD antibody screening in patients on tacrolimus who develop PTDM may identify patients less likely to recover beta cell function with immunosuppression augmentation which requires careful monitoring.

Generating strategies for a national comeback in pancreas transplantation: A Delphi survey and US conference report

In the United States, potential transplant candidates with insulin-dependent diabetes mellitus are inconsistently offered pancreas transplantation (PTx), contributing to a dramatic decline in pancreas allograft utilization over the past 2 decades. The American Society of Transplantation organized a workshop to identify barriers inhibiting PTx and to develop strategies for a national comeback. The 2-day workshop focused on 4 main topics: (1) referral/candidate selection, (2) organ recovery/utilization, (3) program performance/patient outcomes, and (4) enhanced education/research. Topics were explored through expert presentations, patient testimonials, breakout sessions, and strategic planning, including the identification of tasks for immediate focus. Additionally, a modified-Delphi survey was conducted among workshop members to develop and rate the importance of barriers, and the impact and feasibility of workgroup-identified improvement strategies. The panelists identified 16 barriers to progress and 44 strategies for consideration. The steps for a national comeback in PTx involve greater emphasis on efficient referral and candidate selection, better donor pancreas utilization practices, eliminating financial barriers to procurement and transplant, improving collaboration between transplant and diabetes societies and professionals, and increasing focus on PTx training, education, and research. Partnership between national societies, patient advocacy groups, and professionals will be essential to realizing this critical agenda.

The Pancreas After Kidney Transplant is a Competitive Option, Comparable to the Simultaneous Pancreas and Kidney Transplant

BACKGROUND

Simultaneous pancreas and kidney transplant (SPK) is the most common type of pancreas transplant performed worldwide. In contrast, there are a few drawbacks to pancreas after kidney transplant (PAK), such as the requirement for an additional operation, the immunologic risk, etc. SPK is the best option, but because of a lack of deceased donors and a lengthy waiting period, it is not always possible to use it.

METHODS

From 2015 to 2022, we performed 23 SPKs and 21 PAKs at the Pusan National University Yangsan Hospital in Korea. We compared the findings of PAK and SPK conducted within the same time period.

RESULTS

The waiting time for pancreatic graft was significantly shorter in the PAK than SPK group (345 days vs 1350 days, P ≤ .001). Throughout the monitoring period, just 1 pancreatic graft was lost in patients who underwent PAK, and the 7-year graft survival was 95%, with no statistically significant difference compared to SPK (90.3%, P = .600). Moreover, the graft survival of SPK or PAK was superior to that of pancreatic transplant alone (63.7%, P = .016). Only 1 pancreatic graft loss was a case of mortality with a functioning graft. No additional kidney transplant loss was observed in PAK recipients. There was no variation in creatinine levels between the pretransplant and posttransplant periods. There were 2 incidents of pancreatic graft and kidney graft rejection, respectively, but the grafts entirely recovered following rejection treatment.

CONCLUSION

According to our experiences, PAK could be another best choice for individuals with diabetic end-stage renal disease, especially in cases where deceased donors were severely deficient but living donor kidney transplants were actively performed in countries like Korea.

Effect of Remote Ischemic Conditioning on Organ Transplantation: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Remote ischemic conditioning (RIC) has shown great advantages in protecting organs from ischemia-reperfusion loss and applied research on RIC continues to increase. We performed a systematic review and meta-analysis to comprehensively investigate the value of RIC for different organ transplantation.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library from inception to November 1, 2023, for randomized controlled trials investigating whether RIC has an advantage in organ transplantation (including heart, lung, liver, and kidney) compared with controls. The primary outcomes varied according to the transplanted organ, including liver transplantation (graft loss, early allograft dysfunction, acute kidney injury, days in hospital, and mortality); kidney transplantation (delayed graft function, acute rejection (AR), graft loss, 50% decrease in serum creatinine, glomerular filtration rate, days in hospital, and mortality); heart and lung transplantation (AR, mortality). Two investigators independently selected suitable trials, assessed trial quality, and extracted the data.

RESULTS

A total of 11 randomized controlled trials were included in this study, including six kidney transplants, three liver transplants, and one heart and lung transplant each, with 561 RIC cases and 564 controls, and a total of 1125 patients. The results showed that RIC did not reduce mortality in transplant patients compared with controls (liver transplant: RR0.9, 95% confidence interval [0.31-2.66]; kidney transplant: RR 0.76, 95% confidence interval [0.17-3.33]), graft failure rate (liver transplantation: RR 0.3, 95% confidence interval [0.07, 1.19]; kidney transplantation: RR 0.89, 95% confidence interval [0.35, 2.27]), length of hospital stay (liver transplantation: standard mean difference [SMD] 0.14, 95% confidence interval [-0.15, 0.42]; kidney transplantation: SMD -0.1, 95% confidence interval [-0.3, 0.11]). In addition, RIC did not improve early liver function after liver transplantation (RR 0.97, 95% confidence interval [0.55,1.7]), acute kidney injury after liver transplantation (RR 1.17 95% confidence interval [0.9, 1.54]), delayed functional recovery after renal transplantation (RR 0.84, 95% confidence interval [0.62, 1.15]), AR rate (RR 1.04, 95% confidence interval [0.72, 1.49]), 50% serum creatinine decline rate (RR 1.1, 95% confidence interval [0.88, 1.37]), glomerular filtration rate 3 months after surgery (SMD 0.13, 95% confidence interval [-0.05, 0.31]) and postoperative 12 months glomerular filtration rate (SMD 0.13, 95% confidence interval [-0.06, 0.31]).

CONCLUSION

Remote ischemic modulation does not improve clinical outcomes in patients undergoing organ transplantation (heart, lung, liver, and kidney).

Pancreas after kidney transplantation, is it the time to overcome the stigma?

BACKGROUND

Pancreas transplantation is the most effective treatment to improve quality of life and overcome complications in patients with end-stage renal disease and diabetes mellitus. One of the main approaches for concurrent renal disease and diabetes mellitus which has been underutilized during the past decade is a pancreas transplant after kidney transplantation. Our study aimed to quantify outcomes following pancreas after kidney transplants (PAKs) in the United States from 2001 to 2020 with an emphasis on graft and patient survival.

METHODS AND MATERIALS

A retrospective registry analysis was performed by accessing the OPTN/UNOS database for PAKs that were performed in the United States from January 2001 to April 2020. The study population was divided into two subgroups: patients receiving a pancreas transplant between 2001 and 2010 and those receiving a pancreas transplant between 2011 and 2020.

RESULTS

The study examined a total number of 3706 PAK recipients; patients who received a PAK from January 2001 through December 2010 (n = 2892) and those who received a PAK from January 2011 to April 2020 (n = 814). The selection process of transplant recipients did not drastically change throughout the 2001-2010 and 2011-2020 periods. Length of stay at the hospital after the transplantation improved significantly in the 2011-2020 group relative to the 2001-2010 group (8.48 vs. 10.08 days, mean, p < 0.01). Additionally, more transplantation with 4-6 human leukocyte antigen mismatch occurred in the 2011-2020 group than in the 2001-2010 group (80.6% vs. 71.4%, p < 0.01). The pancreas preservation time of 13.35 h in the 2001-2010 group decreased significantly to 11.17 h in the 2011-2020 group (p < 0.001). The mean donor's amylase and lipase also decreased significantly in the 2011-2020 cohort. Significant graft survival improvement was observed in the 2011-2020 group compared to the 2001-2010 group after a long-term follow-up (p < 0.001). The mean Calculated Pancreas Donor Risk Index was 1.08 for the 2001-2010 group and 0.99 for the 2011-2020 group with a significant difference (p < 0.001).

CONCLUSION

The beneficial results and improved outcomes observed in PAK patients demonstrate the effectiveness of the operation for individuals in need of a pancreas transplant. PAKs can prove to be a meaningful solution to overcome long waiting times, decrease the donor-recipient imbalance, expand the donor pool, and overcome the current underutilization in order to improve the short- and long-term quality of life in the groups of interest.

Effects of simultaneous pancreas and kidney transplantation in Japanese individuals with type 1 diabetes and end-stage kidney disease

This single-center observational cohort study aimed to assess the potential benefits of simultaneous pancreas and kidney transplantation (SPK) in terms of mortality and kidney graft outcomes in Japanese individuals with type 1 diabetes (T1D) and end-stage kidney disease (ESKD). We first compared all-cause mortality rates between 78 SPK recipients and 108 non-transplanted individuals with T1D and ESKD. To mitigate the bias stemming from immortal time before receiving SPK, we utilized Cox regression models treating SPK as a time-dependent covariate. Next, we compared all-cause mortality rates and kidney graft loss rates between 65 SPK recipients and 58 kidney transplantation alone (KTA) recipients. Multivariate Cox hazard models and Fine and Gray competing-risk models were employed. SPK recipients experienced significantly lower all-cause mortality rates than non-transplanted individuals, even after accounting for immortal time bias (p = 0.015 by log-rank test, hazard ratio [HR] = 0.334, p = 0.025). When comparing SPK and KTA recipients, no statistically significant difference was observed in mortality rates (HR = 0.627, p = 0.588 by Cox model; HR = 0.385, p = 0.412 by Fine and Gray model) or kidney graft loss rates (HR = 0.612, p = 0.436 by Cox model; HR = 0.639, p = 0.376 by Fine and Gray model). Dysglycemia-associated mortality were observed in non-transplanted individuals and KTA recipients, but not in SPK recipients. These findings highlight the potential life-saving impact of SPK compared with intensive insulin therapy and dialysis. Additionally, this study suggests that both SPK and KTA may offer comparable outcomes. These findings have significant implications for clinical decision-making in the context of organ transplantation for individuals with T1D and ESKD.

Multi-Centre UK Analysis of Simultaneous Pancreas and Kidney (SPK) Transplant in Recipients With Type 2 Diabetes Mellitus

90% of the UK diabetic population are classified as T2DM. This study aims to compare outcomes after SPK transplant between recipients with T1DM or T2DM. Data on all UK SPK transplants from 2003-2019 were obtained from the NHSBT Registry (n = 2,236). Current SPK transplant selection criteria for T2DM requires insulin treatment and recipient BMI < 30 kg/m2. After exclusions (re-transplants/ambiguous type of diabetes) we had a cohort of n = 2,154. Graft (GS) and patient (PS) survival analyses were conducted using Kaplan-Meier plots and Cox-regression models. Complications were compared using chi-squared analyses. 95.6% of SPK transplants were performed in recipients with T1DM (n = 2,060). Univariate analysis showed comparable outcomes for pancreas GS at 1 year (p = 0.120), 3 years (p = 0.237), and 10 years (p = 0.196) and kidney GS at 1 year (p = 0.438), 3 years (p = 0.548), and 10 years (p = 0.947). PS was comparable at 1 year (p = 0.886) and 3 years (p = 0.237) and at 10 years (p = 0.161). Multi-variate analysis showed comparable outcomes in pancreas GS (p = 0.564, HR 1.221, 95% CI 0.619, 2.406) and PS(p = 0.556, HR 1.280, 95% CI 0.563, 2.911). Comparable rates of common complications were demonstrated. This is the largest series outside of the US evaluating outcomes after SPK transplants and shows similar outcomes between T1DM and T2DM recipients. It is hoped dissemination of this data will lead to increased referral rates and assessment of T2DM patients who could benefit from SPK transplantation.

Transportability of causal inference under random dynamic treatment regimes for kidney-pancreas transplantation

A difficult decision for patients in need of kidney-pancreas transplant is whether to seek a living kidney donor or wait to receive both organs from one deceased donor. The framework of dynamic treatment regimes (DTRs) can inform this choice, but a patient-relevant strategy such as "wait for deceased-donor transplant" is ill-defined because there are multiple versions of treatment (i.e., wait times, organ qualities). Existing DTR methods average over the distribution of treatment versions in the data, estimating survival under a "representative intervention." This is undesirable if transporting inferences to a target population such as patients today, who experience shorter wait times thanks to evolutions in allocation policy. We, therefore, propose the concept of a generalized representative intervention (GRI): a random DTR that assigns treatment version by drawing from the distribution among strategy compliers in the target population (e.g., patients today). We describe an inverse-probability-weighted product-limit estimator of survival under a GRI that performs well in simulations and can be implemented in standard statistical software. For continuous treatments (e.g., organ quality), weights are reformulated to depend on probabilities only, not densities. We apply our method to a national database of kidney-pancreas transplant candidates from 2001-2020 to illustrate that variability in transplant rate across years and centers results in qualitative differences in the optimal strategy for patient survival.

When pancreata fly: Outcomes and lessons learned from the development of a Pancreas Transplant Import Program

BACKGROUND

To address long waitlist times and increase pancreas transplantation, our center has implemented a protocol for long-distance importation of pancreata.

METHODS

We conducted a retrospective review of pancreas transplantation at our institution from January 1, 2014, the start of our importation program, through September 30, 2021. Outcomes were compared between locally procured grafts and imported grafts, defined as grafts procured greater than 250 nautical miles (NM) from our center.

RESULTS

Eighty-one patients underwent pancreas transplantation during the study time period; 19 (23.5%) received imported grafts. There were no significant differences in recipient demographics or type of transplant received. Mean distance of import was 644.2 ± 234.0 NM. Imported grafts were more likely to be from pediatric donors <18 years old (p = .02) and a significantly higher proportion of imported grafts came from donors weighing <30 kg (26.3 vs. 3.2%, p = .007). Cold ischemic time was longer for imported grafts than for local grafts (13.4 ± 2.3 h vs. 9.8 ± 2.2 h, p < .01). There was no significant difference in deaths or graft losses within 90 days or at 1 year between groups.

CONCLUSION

Centers should consider expanding criteria for acceptance of imported pancreata to increase the number of transplants and combat organ nonutilization.

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.

Pancreas transplantation with grafts obtained from donation after cardiac death or donation after brain death results in comparable outcomes

Introduction

Pancreas organ shortages and long recipient waitlist times are critical components that limit recipients from receiving a pancreas transplant. Over the last decade, our center has been using donation after cardiac death (DCD) donors as an adjunct to donation after brain death (DBD) donors to expand the organ pool. The aim of this study was to compare recipient and graft survival between DCD and DBD recipients.

Methods

A retrospective single center propensity matched analysis (2011-2020) of 32 DCD vs 96 DBD pancreas transplants was performed.

Results

8-year recipient survival was similar between DCD and DBD groups (87.4% vs 92.7%, p=0.35) as was simultaneous kidney and pancreas transplant (SPK) 8-year kidney (88.9 vs 96.9%, p=0.219) and pancreas graft survival (77.4% vs 86.7%, p=0.344). There was no difference in vascular thrombosis rate between DCD and DBD pancreas grafts (3.1% vs 7.3%, p=0.73). DCD kidneys had a higher rate of DGF vs DBD kidneys (28.1% vs 6.3%, p=0.004), without any significant difference in long term kidney failure (12.5% vs 8.3%, p=0.5).

Discussion

Recipients of DCD grafts demonstrate equivalent long-term patient and graft survival compared to DBD recipients for pancreas transplantation. Increased utilization of well selected DCD donors is a safe strategy to increase the donor pool.

A comprehensive update of the metabolic and toxicological considerations for immunosuppressive drugs used during pancreas transplantation

INTRODUCTION

Despite significant advancements in immunosuppressive regimens and surgical techniques, the prevalence of adverse events related to immunosuppression remains a major challenge affecting the long-term survival rates of pancreas and kidney allografts.

AREAS COVERED

This article presents a comprehensive review of the literature and knowledge (Jan/2012-Feb/2023) concerning glucose metabolism disorders and nephrotoxicity associated with tacrolimus and mammalian target of rapamycin inhibitors (mTORi). Novel signaling pathways potentially implicated in these adverse events are discussed. Furthermore, we extensively examine the findings from clinical trials evaluating the efficacy and safety of tacrolimus, mTORi, and steroid minimization.

EXPERT OPINION

Tacrolimus-based regimens continue to be the standard treatment following pancreas transplants. However, prolonged use of tacrolimus and mTORi may lead to hyperglycemia and nephrotoxicity. Understanding and interpreting experimental data, particularly concerning novel signaling pathways beyond calcineurin-NFAT and mTOR pathways, can offer valuable insights for therapeutic interventions to mitigate hyperglycemia and nephrotoxicity. Additionally, critically analyzing clinical trial results can identify opportunities for personalized safety-based approaches to minimize side effects. It is imperative to conduct randomized-controlled studies to assess the impact of mTORi use and steroid-free protocols on pancreatic allograft survival. Such studies will aid in tailoring treatment strategies for improved transplant outcomes.

Comparison of Outcomes and Survival of Two Cohorts of Patients with Simultaneous Pancreas-Kidney Transplantation: A Retrospective Cohort Study in a Latin American Hospital

Background

Simultaneous pancreas-kidney transplantation (SPKT) is a complex and demanding procedure with a considerable risk of morbidity and mortality. Advances in surgical techniques and organ preservation have introduced changes in care protocols. Two cohorts of patients receiving SPKT with two different protocols were compared to determine overall survival and pancreatic and renal graft failure-free survival.

Methods

This retrospective observational study was conducted in two cohorts of SPKT recipient patients that underwent surgery between 2001 and 2021. Outcomes were compared in transplant patients between 2001 and 2011 (cohort 1; initial protocol) and 2012-2021 (cohort 2; improved protocol). In addition to the temporality, the cohorts were defined by a protocolization of technical aspects and medical management in cohort 2 (improved protocol), compared to a wide variability in the procedures carried out in cohort 1 (initial protocol). Overall survival and pancreatic and renal graft failure-free survival were the primary outcomes. These outcomes were determined using Kaplan-Meier survival analysis and the log-rank test.

Results

Fifty-five SPKT were performed during the study period: 32 in cohort 1 and 23 in cohort 2. In the survival analysis, an average of 2546 days (95% CI: 1902-3190) was found in cohort 1, while in cohort 2, it was 2540 days (95% CI: 2100-3204) (p > 0.05). Pancreatic graft failure-free survival had an average of 1705 days (95% CI: 1037-2373) in cohort 1, lower than the average in cohort 2 (2337 days; 95% CI: 1887-2788) (p = 0.016). Similarly, renal graft failure-free survival had an average of 2167 days (95% CI: 1485-2849) in cohort 1, lower than the average in cohort 2 (2583 days; 95% CI: 2159-3006) (p = 0.017).

Conclusions

This analysis indicates that pancreatic and renal graft failure-free survival associated with SPKT decreased significantly in cohort 2, with results related to improvements in the treatment protocol implemented in that cohort.

An Initial Analysis of the Baseline Levels of Dd-cfDNA After Pancreas Transplantation: A Prospective Study From High-volume Centers in the United States

Pancreas transplantation offers patients with diabetes an opportunity for glucose homeostasis. Current blood tests to surveil for rejection have poor sensitivity and specificity for identifying rejection, and pancreas biopsies are challenging and associated with morbidity and graft loss. Donor-derived cell-free DNA (dd-cfDNA) is shed from transplanted organs and detectable in peripheral blood. Thus, a potential dd-cfDNA blood test assessing rejection would be clinically advantageous.

Methods

One hundred eighty-one dd-cfDNA samples (n) were collected from 77 patients (N) up to 132 mo posttransplant.

Results

The median dd-cfDNA level among all subjects was 0.28% (0.13%, 0.71%). In simultaneous pancreas-kidney (SPK) transplant recipients, the median dd-cfDNA level was 0.29% (0.13%, 0.71%), and it was 0.23% (0.08%, 0.71%) in pancreas transplant alone (PTA) recipients. When isolating for when without infection or rejection, the median dd-cfDNA level was 0.28% (0.13%, 0.64%) for SPK and 0.20% (0.00%, 0.32%) for PTA. Both transplant types approached 1.0% ≤1 mo posttransplant followed by a decrease in median dd-cfDNA. During episodes of rejection or infection, median dd-cfDNA levels were greater among all transplant types.

Conclusions

The mean dd-cfDNA level for all pancreas transplant recipients is <1.0%, consistent with the published kidney transplant rejection threshold (>1.0%), regardless of SPK or PTA. Early posttransplant dd-cfDNA levels are transiently higher than later measurements. Dd-cfDNA elevation also correlates with rejection and infection and thus is a promising biomarker for surveilling pancreas transplant dysfunction.

Pancreas Transplantation: Current Challenges, Considerations, and Controversies

Pancreas transplantation (PTx) reestablishes an autoregulating source of endogenous insulin responsive to normal feedback controls. In addition to achieving complete β-cell replacement that frees the patient with diabetes from the need to monitor serum glucose and administer exogenous insulin, successful PTx provides counterregulatory hormone secretion and exocrine function. A functioning PTx mitigates glycemic variability, eliminates the daily stigma and burden of diabetes, restores normal glucose homeostasis in patients with complicated diabetes, and improves quality of life and life expectancy. The tradeoff is that it entails a major surgical procedure and requisite long-term immunosuppression. Despite the high likelihood of rendering patients euglycemic independent of exogenous insulin, PTx is considered a treatment rather than a cure. In spite of steadily improving outcomes in each successive era coupled with expansion of recipient selection criteria to include patients with a type 2 diabetes phenotype, a decline in PTx activity has occurred in the new millennium related to a number of factors including: (1) lack of a primary referral source and general acceptance by the diabetes care community; (2) absence of consensus criteria; and (3) access, education, and resource issues within the transplant community. In the author's experience, patients who present as potential candidates for PTx have felt as though they needed to circumvent the conventional diabetes care model to gain access to transplant options. PTx should be featured more prominently in the management algorithms for patients with insulin requiring diabetes who are failing exogenous insulin therapy or experiencing progressive diabetic complications regardless of diabetes type. Furthermore, all patients with diabetes and chronic kidney disease should undergo consideration for simultaneous pancreas-kidney transplantation independent of geography or location.

Patient and graft survival in pancreas transplant recipients: The EFISPAN study

INTRODUCTION AND OBJECTIVES

Graft outcomes in pancreas transplantation have improved in recent decades, but data are mainly derived from registries or prospective single-centre studies. This large epidemiological study was undertaken to investigate the impact of clinical and demographic factors on graft and patient survival in pancreas transplant recipients in Spain, and to provide robust, country-wide, practice-based data to complement registry findings.

PATIENTS AND METHODS

We conducted a retrospective, longitudinal, epidemiological study to assess risk factors impacting patient and graft survival in pancreas transplant recipients in eight centres in Spain. All patients transplanted between 1 January 2008 and 31 December 2012 were included; data were collected until 31 December 2015. The Kaplan-Meier method was used for all time-to-event analyses, including patient survival, graft survival, acute rejection, and BPAR. For graft survival analysis, in cases of death with functioning graft, patients were censored without any event on the date of death. For acute rejection and BPAR, patients were censored without any event on the date of death or graft loss. Univariable and multivariable analyses (Cox proportional hazards model) were conducted to assess the association between baseline clinical and demographic characteristics and patient/graft survival.

RESULTS

Data were included for 241 (80.1%) simultaneous pancreas-kidney transplants, 56 (18.6%) pancreas-after-kidney transplants and 4 (1.3%) pancreas transplants alone. Mean±standard deviation time from diagnosis until transplantation was 26.1±7.5 years. Nineteen patients died, mainly due to infections (n=10); the remaining 282 patients (93.7%) survived from transplantation until the end of the study. Among 55 patients (18.3%) with pancreas graft loss, the main reasons were vascular thrombosis (n=19), chronic rejection (n=10), acute rejection (n=6) and death with a functioning graft (n=5). The overall rate of vascular-related death was 1.3% at 5 years post transplant. Univariable analysis showed that patient age and weight, donor age, previous kidney transplantation, previous cardiovascular events and need for insulin more than 48h post transplantation were significantly associated with pancreas graft survival. Of these, in multivariable analyses pancreas graft survival was inferior in patients who had received a previous kidney transplant prior to pancreas transplantation (log-rank test, p=0.0002). Glucose metabolism, renal function and cardiovascular risk factors were generally stable following transplantation.

CONCLUSIONS

The results of this multicentre study highlight the excellent patient and graft outcomes following pancreas transplantation, with a notably low incidence of cardiovascular events.

Modern indications for referral for kidney and pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation (PTx) is currently the only therapy that can predictably achieve sustained euglycemia independent of exogenous insulin administration in patients with insulin-dependent diabetes mellitus. This procedure involves a complex abdominal operation and lifetime dependence on immunosuppressive medications. Therefore, PTx is most frequently performed in combination with other organs, usually a kidney transplant for end stage diabetic nephropathy. Less frequently, solitary PTx may be indicated in patients with potentially life-threatening complications of diabetes mellitus. There remains confusion and misperceptions regarding indications and timing of patient referral for PTx.

RECENT FINDINGS

In this review, the referral, evaluation, and listing process for PTx is described, including a detailed discussion of candidate assessment, indications, contraindications, and outcomes.

SUMMARY

Because the progression of diabetic kidney disease may be less predictable than other forms of kidney failure, early referral for planning of renal and/or pancreas transplantation is paramount to optimize patient care and allow for possible preemptive transplantation.

From islet of Langerhans transplantation to the bioartificial pancreas

Type 1 diabetes is a disease resulting from autoimmune destruction of the insulin-producing beta cells in the pancreas. When type 1 diabetes develops into severe secondary complications, in particular end-stage nephropathy, or life-threatening severe hypoglycemia, the best therapeutic approach is pancreas transplantation, or more recently transplantation of the pancreatic islets of Langerhans. Islet transplantation is a cell therapy procedure, that is minimally invasive and has a low morbidity, but does not display the same rate of functional success as the more invasive pancreas transplantation because of suboptimal engraftment and survival. Another issue is that pancreas or islet transplantation (collectively known as beta cell replacement therapy) is limited by the shortage of organ donors and by the need for lifelong immunosuppression to prevent immune rejection and recurrence of autoimmunity. A bioartificial pancreas is a construct made of functional, insulin-producing tissue, embedded in an anti-inflammatory, immunomodulatory microenvironment and encapsulated in a perm-selective membrane allowing glucose sensing and insulin release, but isolating from attacks by cells of the immune system. A successful bioartificial pancreas would address the issues of engraftment, survival and rejection. Inclusion of unlimited sources of insulin-producing cells, such as xenogeneic porcine islets or stem cell-derived beta cells would further solve the problem of organ shortage. This article reviews the current status of clinical islet transplantation, the strategies aiming at developing a bioartificial pancreas, the clinical trials conducted in the field and the perspectives for further progress.

Early Increases in Posttransplant Pancreatic Enzymes Are Associated With Surgical Complications But Not Graft Failure Among Pancreas Transplant Recipients

OBJECTIVES

This study aimed to find the association between immediate postoperative increases in pancreatic enzymes and posttransplant complications among pancreas transplant recipients (PTRs).

METHODS

We analyzed all PTRs transplanted at the University of Wisconsin between June 2009 and September 2018. Enzyme levels were presented as a ratio of absolute numbers to the upper limit of normal value, with value >1 considered as abnormal. We specifically evaluated bleeding, fluid collections, and thrombosis complications based on the amylase or lipase ratios on day 1 (Amylase1, Lipase1) and maximum ratios within 5 days of transplant (Amylasemax, Lipasemax). For early complications, we focused on technical complications that occurred within 90 days of transplant. For long-term outcomes, we assessed patient and graft survival, and rejections.

RESULTS

There were a total of 443 PTRs, 287 were simultaneous pancreas and kidney recipients, and 156 were solitary pancreas recipients. Higher Amylase1, Liplase1, Amylasemax, and Lipasemax were associated with an increase in early complications, mainly need for pancreatectomy, fluid collections, bleeding complications, or graft thrombosis, particularly in the solitary pancreas group.

CONCLUSIONS

Our finding suggests that cases of early perioperative enzyme increase merit consideration for early imaging investigation to mitigate detrimental outcomes.

Pancreatic transplant surgery and stem cell therapy: Finding the balance between therapeutic advances and ethical principles

The latest achievements in the field of pancreas transplantation and stem cell therapy require an effort by the scientific community to clarify the ethical implications of pioneering treatments, often characterized by high complexity from a surgical point of view, due to transplantation of multiple organs at the same time or at different times, and from an immunological point of view for stem cell therapy. The fundamental value in the field of organ transplants is, of course, a solidarity principle, namely that of protecting the health and life of people for whom transplantation is a condition of functional recovery, or even of survival. The nature of this value is that of a concept to which the legal discipline of transplants entrusts its own ethical dignity and for which it has ensured a constitutional recognition in different systems. The general principle of respect for human life, both of the donor and of the recipient, evokes the need not to put oneself and one’s neighbor in dangerous conditions. The present ethical reflection aims to find a balance between the latest therapeutic advances and several concepts including the idea of the person, the respect due to the dead, the voluntary nature of the donation and the consent to the same, the gratuitousness of the donation, the scientific progress and the development of surgical techniques, and the policies of health promotion.

Association of human leukocyte antigen mismatches between donor-recipient and donor-donor in pancreas after kidney transplant recipients

The effects of HLA mismatching on pancreas outcomes among pancreas after kidney (PAK) recipients are undefined. Outcomes might potentially differ depending on whether there is a mismatch between pancreas donor and recipient (PD-R) or pancreas donor and kidney donor(PD-KD). All primary PAK at our centre were included in this study. Patients were divided into two groups based on the degree of HLA mismatching: low (L-MM) as 0-4 and high (H-MM) as 5-6. We analysed all (N = 73) PAK for PD-R mismatch and the subset of PAK for PD-KD mismatch (N = 71). Comparing PD-R L-MM (n = 39) and H-MM (n = 34) PAKs, we observed no difference in the rate of pancreas graft failure. There was also no difference in the rate of rejection (L-MM 33% vs. H-MM 41%) or the severity of rejection. However, we observed a significantly (P < 0.01) shorter time to acute pancreas rejection in the H-MM group (6.8 ± 8.7 mo) versus the L-MM cohort (29.0 ± 36.2 mo) (P < 0.001). Similar to the PD-R mismatched cohort, we did not observe a detrimental effect of HLA mismatching on graft outcomes in the PD-KD cohort; time to rejection was again shorter in the H-MM subset. In this study, we found no impact of HLA mismatch on either pancreas graft survival or rejection rates, though rejection occurred earlier in high mismatched PAK transplants.

Single center results of simultaneous pancreas-kidney transplantation in patients with type 2 diabetes

Studies have found similar outcomes of Simultaneous Pancreas-Kidney transplantation (SPKT) in patients with Type 2 (T2D) and Type 1 diabetes (T1D). However, there are scarce data evaluating the association of recipient factors such as age, BMI, or pretransplant insulin requirements with outcomes, thus the criteria for the optimal recipient selection remains unclear. In this study, 284 T1D and 39 T2D patients, who underwent SPKT between 2006 and 2017 with 1 year of follow-up at minimum, were assessed for potential relationship of pretransplant BMI and insulin requirements with posttransplant diabetes and pancreatic graft failure. Kaplan-Meier analysis showed similar rates of freedom from posttransplant diabetes (94.7% T2D vs. 92.3% T1D at 1 yr, and 88.1% T2D vs. 81.1% T1D at 5 yrs) and graft survival (89.7% T2D vs. 90.4% T1D at 1 yr, and 89.7% T2D vs. 81.2% T1D at 5 yrs). There was no significant association between BMI or pretransplant insulin requirements with posttransplant diabetes occurrence in either T1D (p = .10, .43, respectively) or T2D (p = .12, .63) patients in the cohort; or with graft failure (T1D: p = .40, .09; T2D: p = .71, .28). These observations suggest a less restricted approach to selective use of SPKT in patients with T2D.

Current state of pancreas transplantation in Japan based on the nationwide registry

In Japan, 437 pancreas transplantations (PTx) were carried out between 2000 and 2019. Clinical data for all PTx cases are registered in the Japan Pancreas Transplant Registry of the Japan Society for Pancreas and Islet Transplantation. Here we analyzed the registry data to describe the current status of PTx in Japan. The 437 PTx included 410 from deceased donors (407 from brain-dead and 3 from non-heart-beating donors) and 27 from living donors. We investigated the clinical characteristics of the 410 PTx from deceased donors. The rate of marginal donors using expanded donor criteria was higher in Japan than in other countries. At 1/5/10 years post-PTx, the overall survival rates were 95.8%/94.2%/88.7%, and the graft survival rates were 85.9%/76.2%/67.4% for pancreas and 93.2%/90.8%/78.2% for kidney (non-censored for death). These rates were comparable to those in other countries. When stratified by PTx category, survival was significantly better following simultaneous pancreas-kidney transplantation (SPK) compared to pancreas-after-kidney transplantation (PAK) or PTx alone (PTA). Immunological rejection was more frequently the cause of graft loss in PAK/PTA cases than in SPK cases, potentially contributing to the poorer survival in PAK/PTA. These outcomes highlight two main concerns: substantial incidence of pancreas graft loss, and inferior outcomes after PAK/PTA. Overall, PTx outcome is favorable in Japan, despite the high rate of marginal donors. To improve outcomes, it is important to prevent and manage each cause of pancreas graft loss. Overcoming the poorer survival in PAK/PTA may require new immunosuppressive protocols or allogenic islet transplantation.

Transplant Options for Patients With Diabetes and Advanced Kidney Disease: A Review

Optimal glycemic control in kidney transplant recipients with diabetes is associated with improved morbidity and better patient and allograft survival. Transplant options for patients with diabetes requiring insulin therapy and chronic kidney disease who are suitable candidates for kidney transplantation should include consideration of β-cell replacement therapy: pancreas or islet transplantation. International variation related to national regulatory policies exists in offering one or both options to suitable candidates and is further affected by pancreas/islet allocation policies and transplant waiting list dynamics. The selection of appropriate candidates depends on patient age, coexistent morbidities, the timing of referral to the transplant center (predialysis versus on dialysis) and availability of living kidney donors. Therefore, early referral (estimated glomerular filtration rate < 30 mL/min/1.73 m²) is of the utmost importance to ensure adequate time for informed decision making and thorough pretransplant evaluation. Obesity, cardiovascular disease, peripheral vascular disease, smoking, and frailty are some of the conditions that need to be addressed before acceptance on the transplant list, and ideally before dialysis becoming imminent. This review offers insights into selection of pancreas/islet transplant candidates by transplant centers and an update on posttransplant outcomes, which may have practice implications for referring nephrologists.

Influence of dialysis duration on outcomes of simultaneous pancreas-kidney transplant

OBJECTIVE

The objective of this study was to assess how pre-transplant dialysis duration affects transplant outcomes after simultaneous pancreas-kidney transplant (SPK) in patients with type 1 diabetes mellitus (T1DM).

METHODS

Data of 6887 T1DM patients who underwent SPK transplantation between 2008 and 2018 were obtained from the Scientific Registry of Transplant Recipients database. According to pre-transplant dialysis duration, the patients were divided into the preemptive SPK, 0-2 years, 2-5 years, and >5 years dialysis groups. Kaplan-Meier survival analysis was performed to compare patient and graft survival among the groups. Univariate and multivariate Cox regression analyses were used to identify predictors of transplant outcomes.

RESULTS

The mean follow-up period was 56.7 ± 34.7 months. Compared with no dialysis or preemptive SPK, dialysis for 0-2 years was not significantly associated with patient or kidney graft survival, while long-term dialysis of 2-5 years and >5 years was significantly associated with increased risk of death and kidney graft failure. However, the duration of dialysis was not associated with pancreas graft survival.

CONCLUSION

Long-term dialysis duration before SPK transplant is an independent predictor of patient death and kidney graft failure in T1DM patients.

Pancreas transplant versus islet transplant versus insulin pump therapy: in which patients and when?

PURPOSE OF REVIEW

The aim of the present review is to gather recent reports on the use of pancreas and islet transplantation and conventional insulin therapy for treating patients experiencing diabetes and its related complications. The present review directs attention to the current status, challenges and perspectives of these therapies and sheds light on potential future cellular therapies.

RECENT FINDINGS

The risks and benefits of diabetes treatment modalities continue to evolve, altering the risk versus benefit calculation for patients. As continuous subcutaneous insulin infusion and monitoring technologies demonstrate increasing effectiveness in achieving better diabetes control and reducing hypoglycemia frequency, so are pancreas and islet transplantation improving and becoming more effective and safer. Both beta-cell replacement therapies, however, are limited by a dependence on immunosuppression and a shortage of cadaver donors, restricting more widespread and safer deployment. Based on the effectiveness of clinical beta-cell replacement for lengthening lifespan and improving quality of life, scientists are aggressively investigating alternative cell sources, transplant platforms, and means of preventing immunological damage of transplanted cells to overcome these principle limitations.

SUMMARY

Essential goals of diabetes therapy are euglycemia, avoidance of hypoglycemia, and prevention or stabilization of end-organ damage. With these goals in mind, all therapeutic options should be considered.

Kidney-Pancreas Transplant Recipients Experience Higher Risk of Complications Compared to the General Population after Undergoing Coronary Artery Bypass Grafting

This retrospective analysis aims to identify differences in surgical outcomes between pancreas and/or kidney transplant recipients compared with the general population undergoing coronary artery bypass grafting (CABG). Using Nationwide Inpatient Sample (NIS) data from 2005 to 2014, patients who underwent CABG were stratified by either no history of transplant, or history of pancreas and/or kidney transplant. Multivariate analysis was used to calculate odds ratio (OR) to evaluate in-hospital mortality, morbidity, length of stay (LOS), and total hospital charge in all centers. The analysis was performed for both nonemergency and emergency CABG. Overall, 2,678 KTx (kidney transplant alone), 184 PTx (pancreas transplant alone), 254 KPTx (kidney-pancreas transplant recipients), and 1,796,186 Non-Tx (nontransplant) met inclusion criteria. KPTx experienced higher complication rates compared with Non-Tx (78.3 vs. 47.8%, p  < 0.01). Those with PTx incurred greater total hospital charge and LOS. On weighted multivariate analysis, KPTx was associated with an increased risk for developing any complication following CABG (OR 3.512, p  < 0.01) and emergency CABG (3.707, p  < 0.01). This risk was even higher at transplant centers (CABG OR 4.302, p  < 0.01; emergency CABG OR 10.072, p  < 0.001). KTx was associated with increased in-hospital mortality following emergency CABG, while PTx and KPTx had no mortality to analyze. KPTx experienced a significantly higher risk of complications compared with the general population after undergoing CABG, in both transplant and nontransplant centers. These outcomes should be considered when providing perioperative care.

Single center results of simultaneous pancreas-kidney transplantation in patients with type 2 diabetes

Studies have found similar outcomes of Simultaneous Pancreas-Kidney transplantation (SPKT) in patients with Type 2 (T2D) and Type 1 diabetes (T1D). However, there are scarce data evaluating the association of recipient factors such as age, BMI, or pretransplant insulin requirements with outcomes, thus the criteria for the optimal recipient selection remains unclear. In this study, 284 T1D and 39 T2D patients, who underwent SPKT between 2006 and 2017 with 1 year of follow-up at minimum, were assessed for potential relationship of pretransplant BMI and insulin requirements with posttransplant diabetes and pancreatic graft failure. Kaplan-Meier analysis showed similar rates of freedom from posttransplant diabetes (94.7% T2D vs. 92.3% T1D at 1 yr, and 88.1% T2D vs. 81.1% T1D at 5 yrs) and graft survival (89.7% T2D vs. 90.4% T1D at 1 yr, and 89.7% T2D vs. 81.2% T1D at 5 yrs). There was no significant association between BMI or pretransplant insulin requirements with posttransplant diabetes occurrence in either T1D (p = .10, .43, respectively) or T2D (p = .12, .63) patients in the cohort; or with graft failure (T1D: p = .40, .09; T2D: p = .71, .28). These observations suggest a less restricted approach to selective use of SPKT in patients with T2D.

Is Prophylactic Drainage After Pancreas Transplant Associated With Reduced Reoperation Rate?

OBJECTIVES

Advances in surgery and perioperative care have contributed to improved outcomes after pancreas transplant. However, the development of peripancreatic infections carries a poor prognosis. It is not clear whether abdominal drainage is helpful in collection prevention.

MATERIALS AND METHODS

A retrospective review of adult consecutive pancreas transplants at a single institution between January 2017 and December 2018 was undertaken. Postoperative outcomes were compared between patients in whom prophylactic intraoperative drains were placed and patients with no drains.

RESULTS

We identified 83 patients who underwent pancreas transplant with a median age of 45 years; 54.2% were males, and median body mass index was 25.8. Thirty patients had 1 or 2 drains placed (36.1%). There was no difference in the readmission rate (70.0% vs 60.4%; P = .48), reoperation (20.0% vs 30.2%; P = .44), or percutaneous drainage of peripancreatic infections (20.0% vs 15.1%; P = .56) between patients with drains and no drains, respectively. However, prophylactic drainage was associated with a lower rate of reoperation for peripancreatic infections compared with those who were not drained (0.0% vs 13.2%; P < .05). No graft loss occurred in the drain group.

CONCLUSIONS

Prophylactic drainage after pancreas transplant may be helpful for reduction in the infection rate after reoperation. The risks of drain placement should be weighed against those of drain avoidance.

Outcomes of pancreas transplantation in older diabetic patients

OBJECTIVE

Improvement in insulin alternatives is leading to a delayed presentation of microvascular and macrovascular complications of diabetes. The objective of this study was to evaluate the long-term outcomes of older (≥50 years) diabetic patients who receive a pancreas transplantation (PT).

RESEARCH DESIGN AND METHODS

We retrospectively evaluated all 338 PTs performed at our center between 2000 and 2016 (mean follow-up 9.4±4.9 years). Recipient and graft survivals were estimated for up to 10 years after PT. Major adverse cardiovascular events (MACEs) before and after PT were included in the analysis.

RESULTS

Thirty-nine patients (12%) were ≥50 years old (52.7±2.3 years) at the day of PT, of which 29 received a simultaneous pancreas-kidney transplantation (SPK) and 10 a pancreas after kidney transplantation (PAK). SPK recipients were first transplants, whereas in the PAK up to 50% were pancreas re-transplantations. Recipient and pancreas graft survivals at 10 years were similar between the group <50 years old and the older group for both SPK and PAK (log-rank p>0.05). The prevalence of MACE prior to PT was similar between both groups (31% vs 29%). Following PT, older recipients presented inferior post-transplant MACE-free survival. In a multivariate regression model, diabetes vintage (HR 1.054, p=0.03) and pre-transplantation MACE (HR 1.98, p=0.011), but not recipient age (HR 1.45, p=0.339), were associated with post-transplant MACE.

CONCLUSIONS

Long-term survival of older pancreas transplant recipients are similar to younger counterparts. Diabetes vintage, but not age, increased the risk of post-transplantation MACE. These results suggest pancreas transplantation is a valuable treatment alternative to older diabetic patients.

Pancreas Retransplant After Pancreas Graft Failure in Simultaneous Pancreas-kidney Transplants Is Associated With Better Kidney Graft Survival

Background.

Simultaneous pancreas-kidney (SPK) transplant is usually the best option for the diabetic end-stage renal disease patient. There is limited information about kidney graft outcomes in SPK recipients with isolated pancreas graft failure who do versus do not undergo pancreas retransplantation.

Methods.

Patients were divided into 2 groups based on whether they underwent pancreas retransplant (ReTx⁺) or not (ReTx⁻). Kidney graft function and survival were the primary endpoints.

Results.

One hundred and nine patients satisfied our selection criteria, 25 in ReTx⁺ and 84 in ReTx⁻. Mean interval from SPK to pancreas failure was significantly shorter in the ReTx⁺ compared with the ReTx⁻ group, 19.3 ± 36.7 versus 45.7 ± 47.0 months (P = 0.01), respectively. There was no significant difference in kidney graft follow-up post SPK between 2 groups (P = 0.48). At last follow-up, 15 of the 25 (60%) of the repeat pancreas graft had failed, with a mean graft survival among these failed pancreas graft of 2.6 ± 2.7 years, ranging from 0 to 8.1 years. Uncensored kidney graft failure was significantly lower in the ReTx⁺ group compared with the ReTx⁻ group, 44% versus 67% (P = 0.04). Death-censored kidney graft failure was also lower in the ReTx⁺ group, 24% versus 48% (P = 0.04). The difference in patient survival did not reach statistical significance. In adjusted Cox regression analysis, rejection as a cause of pancreas failure was associated with increased risk of death-censored kidney graft failure, and pancreas retransplantation was associated with decreased risk of kidney graft failure. A similar pattern was seen after 1:1 matching for the interval between SPK and pancreas graft failure.

Conclusions.

Even though ReTx⁺ patients accept the risks associated with repeat pancreas surgery, providers should consider this option in suitable otherwise healthy patients.

Machine Perfusion and the Pancreas: Will It Increase the Donor Pool?

PURPOSE OF REVIEW

Pancreas transplantation enables complete patient independence from exogenous insulin administration and increases both patient survival and quality of life. Despite this, there has been a decline in pancreas transplantation for the past 20 years, influenced by changing donor demographics with more high-risk extended criteria (ECD) and donation after cardiac death (DCD) donors. This review discusses whether the advent of machine perfusion (MP), if extended to the pancreas, can increase the pool of suitable donor organs.

RECENT FINDINGS

Hypothermic and normothermic MP, as forms of preservation deemed superior to cold storage for high-risk kidney and liver donor organs, have opened the avenue for translation of this work into the pancreas. Recent experimental models of porcine and human ex-vivo pancreatic MP are promising. Applications of MP to the pancreas however need refinement-focusing on perfusion protocols and viability assessment tools. Emerging research shows pancreatic MP can potentially offer superior preservation capacity, the ability to both resuscitate and manipulate organs, and assess functional and metabolic organ viability. The future of MP will lie in organ assessment and resuscitation after retrieval, where ultimately organs initially considered high risk and unsuitable for transplantation will be optimised and transformed, making them then available for clinical use, thus increasing the pool of suitably viable pancreata for transplantation.