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

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.

Increase in lumbar spine but not distal radius bone mineral density in adults after pancreas kidney transplantation

Osteoporosis occurs in every third individual after simultaneous pancreas kidney transplantation (SPKT). Currently used bone measures insufficiently predict their fracture risk. Lumbar spine Trabecular bone score (TBS) and distal radius areal and volumetric bone mineral density (BMD) were monitored for the first time in patients with type 1 diabetes and chronic renal failure after SPKT with steroid-sparing protocol. In 33 subjects (mean age 43.4 ± 9.8 years), dual-energy X-ray absorptiometry and peripheral quantitative computed tomography were performed just after SPKT (baseline) and one and three years later. While TBS Z-scores increased (-1.1 ± 1.2 and -0.3 ± 1.0; p˂0.001, at baseline and year three, respectively), trabecular volumetric BMD Z-scores at distal radius metaphysis did not change during the study (-1.3 ± 1.3 and -1.3 ± 1.0; p = 0.38). Similarly, areal BMD Z-scores increased at lumbar spine, total hip and femoral neck (all p < 0.01), but not at the distal radius. SPKT induced bone measures' improvement at lumbar spine and hip but not at distal radius. Before suggesting changes in current clinical care, predictive value of individual bone measures or its combination for fracture risk assessment remains to be elucidated.

Nutritional Considerations for Patients With Renal Failure Undergoing Sleeve Gastrectomy

Obesity is highly prevalent in patients with renal disease, as it contributes to or accelerates the progression of kidney disease and is frequently a barrier to kidney transplantation. Patients with renal disease have unique dietary needs due to various metabolic disturbances resulting from altered processing and clearance of nutrients. They also frequently present with physical disability, resulting in difficulty achieving adequate weight loss through lifestyle modifications. Therefore, kidney transplant candidates may benefit from bariatric surgery, particularly sleeve gastrectomy (SG), as the safest, most effective, and long-lasting weight loss option to improve comorbidities and access to transplantation. However, concerns regarding nutritional risks prevent broader dissemination of SG in this population. No specific guidelines tailored to the nutritional needs of patients with renal disease undergoing SG have been developed. Moreover, appropriate monitoring strategies and interventions for muscle loss and functional status preservation, a major concern in this at-risk population, are unknown. We aimed to summarize the available literature on the nutritional requirements of patients with renal disease seeking SG as a bridge to transplantation. We also provide insight and guidance into the nutritional management pre and post-SG.

Role of Complement-dependent Cytotoxicity Crossmatch and HLA Typing in Solid Organ Transplant

BACKGROUND

Solid organ transplantation is a life-saving medical operation that has progressed greatly because of developments in diagnostic tools and histocompatibility tests. Crossmatching for complement-dependent cytotoxicity (CDC) and human leukocyte antigen (HLA) typing are two important methods for checking graft compatibility and reducing the risk of graft rejection. HLA typing and CDC crossmatching are critical in kidney, heart, lung, liver, pancreas, intestine, and multi-organ transplantation.

METHODS

A systematic literature search was conducted on the internet, using PubMed, Scopus, and Google Scholar databases, to identify peer-reviewed publications about solid organ transplants, HLA typing, and CDC crossmatching.

CONCLUSION

Recent advances in HLA typing have allowed for high-resolution evaluation, epitope matching, and personalized therapy methods. Genomic profiling, next-generation sequencing, and artificial intelligence have improved HLA typing precision, resulting in better patient outcomes. Artificial intelligence (AI) driven virtual crossmatching and predictive algorithms have eliminated the requirement for physical crossmatching in the context of CDC crossmatching, boosting organ allocation and transplant efficiency. This review elaborates on the importance of HLA typing and CDC crossmatching in solid organ transplantation.

[Simultaneous living donor pancreas-kidney transplantation in a patient with type 1 diabetes mellitus after program hemodialysis. Case report]

Simultaneous pancreas-kidney transplantation is an effective treatment option for end-stage renal disease with diabetes mellitus. Successful simultaneous pancreas-kidney transplantation allows achieving euglycemia, stabilizing existing microvascular complications and slowing their progression, improving the patient's quality of life, lipid and calcium-phosphorus metabolism, reducing the risks of cardiovascular events. Therefore, in view of the patient's severe general condition due to prolonged intoxication, hyperglycemia and other complications of chronic kidney disease, the earliest possible surgical treatment with minimization of the patient's stay on dialysis therapy is crucial to improve the outcome of transplantation.

Diabetic Neuropathy Is Independently Associated With Worse Graft Outcomes and Incident Cardiovascular Disease After Pancreas Transplantation: A Retrospective Cohort Study in Type 1 Diabetes

BACKGROUND

Information about the impact of diabetic neuropathy (DN) on outcomes after pancreas transplantation (PT) is scarce. We assessed the independent relationship between DN markers with both graft survival and incident cardiovascular disease (CVD) after transplantation.

METHODS

A cohort study in individuals with type 1 diabetes and end-stage kidney disease who underwent PT between 1999 and 2015 was conducted. DN was assessed with vibration perception thresholds (VPTs) and orthostatic hypotension (pre-PT and 6 mo, 2-3, 5-6, and 8-10 y after transplantation). Pretransplantation and posttransplantation DN markers were related with graft failure/dysfunction and incident CVD during follow-up.

RESULTS

We included 187 participants (70% men, age 39.9 ± 7.1 y, diabetes duration 27.1 y), with a median follow-up of 11.3 y. Abnormal VPTs (≥25 V) were observed in 53%. After transplantation, VPTs improved (22.4 ± 8.4 pretransplant versus 16.1 ± 6.1 V at 8-10 y post-PT; P < 0.001); additionally, the prevalence of abnormal VPTs decreased (53% pretransplant versus 24.4% at 8-10 y; P < 0.001). After adjusting for age, sex, diabetes duration, blood pressure, body mass index, and previous CVD, pretransplant VPTs ≥25 V were independently associated with pancreas graft failure/dysfunction (hazard ratio [HR], 2.01 [1.01-4.00]) and incident CVD (HR, 2.57 [1.17-5.64]). Furthermore, persistent abnormal VPTs after 6 mo posttransplantation were associated with the worst outcomes (HR, 2.80 [1.25-6.23] and HR, 3.19 [1.14-8.96], for graft failure/dysfunction and incident CVD, respectively).

CONCLUSIONS

In individuals with type 1 diabetes and end-stage kidney disease, PT was associated with an improvement of VPTs. This simple and widely available DN study was independently associated with pancreas graft function and CVD posttransplantation.

Comprehensive review: Frailty in pancreas transplant candidates and recipients

Well-selected patients with kidney disease and diabetes mellitus who undergo simultaneous kidney-pancreas transplantation often experience dramatic improvements in quality of life and long-term survival compared to those who remain on medical therapy. Over the past several years the importance of frailty in the pancreas transplant candidate and recipient populations has grown. More patients with advanced age have entered the waitlist, and complications from prolonged diabetes, even in younger patients, have created increased evidence of risk for frailty. Given these concerns, and the broad challenges facing pancreas transplantation volumes overall, we generated this review to help establish the impact and implications. We summarize the interplay of immunological factors, aging, environmental factors, diabetes mellitus, and chronic kidney disease that put these patients at risk for frailty. We discuss its measurement and recommend a combination of two instruments (both well-validated and one entirely objective). We describe the outcomes for patients before and after pancreas transplantation who may have frailty, and what interventions can be taken to mitigate its effects. Broader investigation into frailty in the pancreas transplant population is needed to better understand how to select patients for pancreas transplantation and to how manage its consequences thereafter.

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.

Donor-derived Cell-free DNA Shows High Sensitivity for the Diagnosis of Pancreas Graft Rejection in Simultaneous Pancreas-kidney Transplantation

BACKGROUND

Pancreas graft status in simultaneous pancreas-kidney transplant (SPKTx) is currently assessed by nonspecific biochemical markers, typically amylase or lipase. Identifying a noninvasive biomarker with good sensitivity in detecting early pancreas graft rejection could improve SPKTx management.

METHODS

Here, we developed a pilot study to explore donor-derived cell-free DNA (dd-cfDNA) performance in predicting biopsy-proven acute rejection (P-BPAR) of the pancreas graft in a cohort of 36 SPKTx recipients with biopsy-matched plasma samples. dd-cfDNA was measured using the Prospera test (Natera, Inc.) and reported both as a fraction of the total cfDNA (fraction; %) and as concentration in the recipient's plasma (quantity; copies/mL).

RESULTS

In the absence of P-BPAR, dd-cfDNA was significantly higher in samples collected within the first 45 d after SPKTx compared with those measured afterward (median, 1.00% versus 0.30%; median, 128.2 versus 35.3 cp/mL, respectively with both; P  = 0.001). In samples obtained beyond day 45, P-BPAR samples presented a significantly higher dd-cfDNA fraction (0.83 versus 0.30%; P  = 0.006) and quantity (81.3 versus 35.3 cp/mL; P  = 0.001) than stable samples. Incorporating dd-cfDNA quantity along with dd-cfDNA fraction outperformed dd-cfDNA fraction alone to detect active rejection. Notably, when using a quantity cutoff of 70 cp/mL, dd-cfDNA detected P-BPAR with a sensitivity of 85.7% and a specificity of 93.7%, which was more accurate than current biomarkers (area under curve of 0.89 for dd-cfDNA (cp/ml) compared with 0.74 of lipase and 0.46 for amylase).

CONCLUSIONS

dd-cfDNA measurement through a simple noninvasive blood test could be incorporated into clinical practice to help inform graft management in SPKTx patients.

Pancreatic islet transplantation in type 1 diabetes: 20-year experience from a single-centre cohort in Canada

BACKGROUND

Islet transplantation offers an effective treatment for selected people with type 1 diabetes and intractable hypoglycaemia. Long-term experience, however, remains limited. We report outcomes from a single-centre cohort up to 20 years after islet transplantation.

METHODS

This cohort study included patients older than 18 years with type 1 diabetes undergoing allogeneic islet transplantation between March 11, 1999, and Oct 1, 2019, at the University of Alberta Hospital (Edmonton, AB, Canada). Patients who underwent islet-after-kidney transplantation and islet transplantation alone or islet transplantation before whole-pancreas transplantation (follow-up was censored at the time of whole-pancreas transplantation) were included. Patient survival, graft survival (fasting plasma C-peptide >0·1 nmol/L), insulin independence, glycaemic control, and adverse events are reported. To identify factors associated with prolonged graft survival, recipients with sustained graft survival (≥90% of patient follow-up duration) were compared with those who had non-sustained graft survival (<90% of follow-up duration). Multivariate binary logistic regression analyses were done to determine predictors of sustained graft survival.

FINDINGS

Between March 11, 1999, and Oct 1, 2019, 255 patients underwent islet transplantation and were included in the analyses (149 [58%] were female and 218 [85%] were White). Over a median follow-up of 7·4 years (IQR 4·4-12·2), 230 (90%) patients survived. Median graft survival was 5·9 years (IQR 3·0-9·5), and graft failure occurred in 91 (36%) patients. 178 (70%) recipients had sustained graft survival, and 77 (30%) had non-sustained graft survival. At baseline, compared with patients with non-sustained graft survival, those with sustained graft survival had longer median type 1 diabetes duration (33·5 years [IQR 24·3-41·7] vs 26·2 years [17·0-35·5]; p=0·0003), median older age (49·4 years [43·5-56·1] vs 44·2 years [35·4-54·2]; p=0·0011), and lower median insulin requirements (0·53 units/kg per day [0·45-0·67] vs 0·59 units/kg per day [0·48-0·70]; p=0·032), but median HbA_1c concentrations were similar (8·2% [7·5-9·0] vs 8·5% [7·8-9·2]; p=0·23). 201 (79%) recipients had insulin independence, with a Kaplan-Meier estimate of 61% (95% CI 54-67) at 1 year, 32% (25-39) at 5 years, 20% (14-27) at 10 years, 11% (6-18) at 15 years, and 8% (2-17) at 20 years. Patients with sustained graft survival had significantly higher rates of insulin independence (160 [90%] of 178 vs 41 [53%] of 77; p<0·0001) and sustained improvements in glycaemic control mixed-main-effects model group effect, p<0·0001) compared with those with non-sustained graft survival. Multivariate analyses identified the combined use of anakinra plus etanercept (adjusted odds ratio 7·5 [95% CI 2·7-21·0], p<0·0001) and the BETA-2 score of 15 or higher (4·1 [1·5-11·4], p=0·0066) as factors associated with sustained graft survival. In recipients with sustained graft survival, the incidence of procedural complications was lower (23 [5%] of 443 infusions vs 17 [10%] of 167 infusions; p=0·027), whereas the incidence of cancer was higher (29 of [16%] of 178 vs four [5%] of 77; p=0·015) than in those with non-sustained graft survival; most were skin cancers (22 [67%] of 33). End-stage renal disease and severe infections were similar between groups.

INTERPRETATION

We present the largest single-centre cohort study of long-term outcomes following islet transplantation. Although some limitations with our study remain, such as the retrospective component, a relatively small sample size, and the absence of non-transplant controls, we found that the combined use of anakinra plus etanercept and the BETA-2 score were associated with improved outcomes, and therefore these factors could inform clinical practice.

FUNDING

None.

Temporal Trends in Renal Replacement Therapy in Community-Based People with or without Type 2 Diabetes: The Fremantle Diabetes Study

Background: Although rates of cardiovascular disease complicating type 2 diabetes are declining, equivalent data for renal replacement therapy (RRT) are conflicting. The aim of this study was to characterize temporal changes in RRT incidence rates (IRs) in Australians with or without type 2 diabetes. Methods: Participants with type 2 diabetes from the Fremantle Diabetes Study Phases I (FDS1; n = 1291 recruited 1993–1996) and II (FDS2; n = 1509 recruited 2008–2011) were age-, sex- and postcode-matched 1:4 to people without diabetes and followed for first hospitalization for/with RRT. Five-year IRs, IR ratios (IRRs) for those with versus without diabetes in FDS1 and FDS2, and IR differences (IRDs), were calculated. Results: The 13,995 participants had a mean age of 64.8 years and 50.4% were males. For the type 2 diabetes cohorts, the 5-year RRT IR was nearly threefold higher in FDS2 versus FDS1 (IRR (95% CI): 2.85 (1.01–9.87)). Sixteen more participants with type 2 diabetes/10,000 person-years received RRT in FDS2 than FDS1 compared with an IRD of 2/10,000 person-years in those without diabetes. Type 2 diabetes increased RRT risk at least 5-fold. This increased risk was greater in Aboriginal participants who were relatively young when RRT was initiated and more prone to rapid progression to RRT. Multivariable analysis using the combined FDS type 2 diabetes cohorts confirmed albuminuria as a strong independent RRT risk factor. Conclusions: The incidence of RRT is increasing substantially in Australians with type 2 diabetes, especially in Aboriginals who progress to RRT more rapidly at a younger age than non-Aboriginals.