Risks and benefits of transplantation in the cure of type 1 diabetes: whole pancreas versus islet transplantation. A single center study

Primary Graft Function and 5 Year Insulin Independence After Pancreas and Islet Transplantation for Type 1 Diabetes: A Retrospective Parallel Cohort Study

In islet transplantation (ITx), primary graft function (PGF) or beta cell function measured early after last infusion is closely associated with long term clinical outcomes. We investigated the association between PGF and 5 year insulin independence rate in ITx and pancreas transplantation (PTx) recipients. This retrospective multicenter study included type 1 diabetes patients who underwent ITx in Lille and PTx in Nantes from 2000 to 2022. PGF was assessed using the validated Beta2-score and compared to normoglycemic control subjects. Subsequently, the 5 year insulin independence rates, as predicted by a validated PGF-based model, were compared to the actual rates observed in ITx and PTx patients. The study enrolled 39 ITx (23 ITA, 16 IAK), 209 PTx recipients (23 PTA, 14 PAK, 172 SPK), and 56 normoglycemic controls. Mean[SD] PGF was lower after ITx (ITA 22.3[5.2], IAK 24.8[6.4], than after PTx (PTA 38.9[15.3], PAK 36.8[9.0], SPK 38.7[10.5]), and lower than mean beta-cell function measured in normoglycemic control: 36.6[4.3]. The insulin independence rates observed at 5 years after PTA and PAK aligned with PGF predictions, and was higher after SPK. Our results indicate a similar relation between PGF and 5 year insulin independence in ITx and solitary PTx, shedding new light on long-term transplantation outcomes.

Pancreas and Islet Transplantation: Comparative Outcome Analysis of a Single-centre Cohort Over 20-years

OBJECTIVE

To provide the largest single-center analysis of islet (ITx) and pancreas (PTx) transplantation.

SUMMARY BACKGROUND DATA

Studies describing long-term outcomes with ITx and PTx are scarce.

METHODS

We included adults undergoing ITx (n=266) and PTx (n=146) at the University of Alberta from January 1999 to October 2019. Outcomes include patient and graft survival, insulin independence, glycemic control, procedure-related complications, and hospital readmissions. Data are presented as medians (interquartile ranges, IQR) and absolute numbers (percentages, %) and compared using Mann-Whitney and χ2 tests. Kaplan-Meier estimates, Cox proportional hazard models and mixed main effects models were implemented.

RESULTS

Crude mortality was 9.4% and 14.4% after ITx and PTx, respectively ( P= 0.141). Sex-adjusted and age-adjusted hazard-ratio for mortality was 2.08 (95% CI, 1.04-4.17, P= 0.038) for PTx versus ITx. Insulin independence occurred in 78.6% and 92.5% in ITx and PTx recipients, respectively ( P= 0.0003), while the total duration of insulin independence was 2.1 (IQR 0.8-4.6) and 6.7 (IQR 2.9-12.4) year for ITx and PTx, respectively ( P= 2.2×10 -22 ). Graft failure ensued in 34.2% and 19.9% after ITx and PTx, respectively ( P =0.002). Glycemic control improved for up to 20-years post-transplant, particularly for PTx recipients (group, P= 7.4×10 -7 , time, P =4.8×10 -6 , group*time, P= 1.2×10 -7 ). Procedure-related complications and hospital readmissions were higher after PTx ( P =2.5×10 -32 and P= 6.4×10 -112 , respectively).

CONCLUSIONS

PTx shows higher sex-adjusted and age-adjusted mortality, procedure-related complications and readmissions compared with ITx. Conversely, insulin independence, graft survival and glycemic control are better with PTx. This study provides data to balance risks and benefits with ITx and PTx, which could improve shared decision-making.

The Evolution of Diabetes Treatment Through the Ages: From Starvation Diets to Insulin, Incretins, SGLT2-Inhibitors and Beyond

Diabetes is an ancient disease and for centuries extreme diets and herbal remedies were used to treat diabetes symptoms. The discovery of insulin in 1921 transformed the landscape of diabetes treatment and was followed by the discovery of several new therapies which improved glycemia and increased patient life span. However, as patients with diabetes lived longer, they developed classic microvascular and macrovascular diabetes complications. In the 1990s, the DCCT and the UKPDS trials demonstrated that tight glucose control reduced the microvascular complications of diabetes, but had marginal effects on cardiovascular disease, the leading cause of death in patients with diabetes. In 2008, the FDA directed that all new diabetes medications demonstrate cardiovascular safety. From this recommendation emerged novel therapeutic classes, the GLP-1 receptor agonists and SGLT2-Inhibitors, which not only improve glycemia, but also provide robust cardio-renal protection. In parallel, developments in diabetes technology like continuous glucose monitoring systems, insulin pumps, telemedicine and precision medicine have advanced diabetes management. Remarkably, a century later, insulin remains a cornerstone of diabetes treatment. Also, diet and physical activity remain important components of any diabetes treatment. Today type 2 diabetes is preventable and long-term remission of diabetes is possible. Finally, progress continues in the field of islet transplantation, perhaps the ultimate frontier in diabetes management.

Pathophysiology and management of hypoglycemia in diabetes

In the century since the discovery of insulin, diabetes has changed from an early death sentence to a manageable chronic disease. This change in longevity and duration of diabetes coupled with significant advances in therapeutic options for patients has fundamentally changed the landscape of diabetes management, particularly in patients with type 1 diabetes mellitus. However, hypoglycemia remains a major barrier to achieving optimal glycemic control. Current understanding of the mechanisms of hypoglycemia has expanded to include not only counter-regulatory hormonal responses but also direct changes in brain glucose, fuel sensing, and utilization, as well as changes in neural networks that modulate behavior, mood, and cognition. Different strategies to prevent and treat hypoglycemia have been developed, including educational strategies, new insulin formulations, delivery devices, novel technologies, and pharmacologic targets. This review article will discuss current literature contributing to our understanding of the myriad of factors that lead to the development of clinically meaningful hypoglycemia and review established and novel therapies for the prevention and treatment of hypoglycemia.

Cell Therapy for Type 1 Diabetes: From Islet Transplantation to Stem Cells

The field of cell therapy of type 1 diabetes is a particularly interesting example in the scenario of regenerative medicine. In fact, β-cell replacement has its roots in the experience of islet transplantation, which began 40 years ago and is currently a rapidly accelerating field, with several ongoing clinical trials using β cells derived from stem cells. Type 1 diabetes is particularly suitable for cell therapy as it is a disease due to the deficiency of only one cell type, the insulin-producing β cell, and this endocrine cell does not need to be positioned inside the pancreas to perform its function. On the other hand, the presence of a double immunological barrier, the allogeneic one and the autoimmune one, makes the protection of β cells from rejection a major challenge. Until today, islet transplantation has taught us a lot, pioneering immunosuppressive therapies, graft encapsulation, tissue engineering, and test of different implant sites and has stimulated a great variety of studies on β-cell function. This review starts from islet transplantation, presenting its current indications and the latest published trials, to arrive at the prospects of stem cell therapy, presenting the latest innovations in the field.

Considerations for an Alternative Site of Islet Cell Transplantation

Islet cell transplantation has been limited most by poor graft survival. Optimizing the site of transplantation could improve clinical outcomes by minimizing required donor cells, increasing graft integration, and simplifying the transplantation and monitoring process. In this article, we review the history and significant human and animal data for clinically relevant sites, including the liver, spleen, and kidney subcapsule, and identify promising new sites for further research. While the liver was the first studied site and has been used the most in clinical practice, the majority of transplanted islets become necrotic. We review the potential causes for graft death, including the instant blood-mediated inflammatory reaction, exposure to immunosuppressive agents, and low oxygen tension. Significant research exists on alternative sites for islet cell transplantation, suggesting a promising future for patients undergoing pancreatectomy.

Optimization of Islet Microencapsulation with Thin Polymer Membranes for Long-Term Stability

Microencapsulation of islets can protect against immune reactions from the host immune system after transplantation. However, sufficient numbers of islets cannot be transplanted due to the increase of the size and total volume. Therefore, thin and stable polymer membranes are required for the microencapsulation. Here, we undertook the cell microencapsulation using poly(ethylene glycol)-conjugated phospholipid (PEG-lipid) and layer-by-layer membrane of multiple-arm PEG. In order to examine the membrane stability, we used different molecular weights of 4-arm PEG (10k, 20k and 40k)-Mal to examine the influence on the polymer membrane stability. We found that the polymer membrane made of 4-arm PEG(40k)-Mal showed the highest stability on the cell surface. Also, the polymer membrane did not disturb the insulin secretion from beta cells.

Advances in β-cell replacement therapy for the treatment of type 1 diabetes

The main goal of treatment for type 1 diabetes is to control glycaemia with insulin therapy to reduce disease complications. For some patients, technological approaches to insulin delivery are inadequate, and allogeneic islet transplantation is a safe alternative for those patients who have had severe hypoglycaemia complicated by impaired hypoglycaemia awareness or glycaemic lability, or who already receive immunosuppressive drugs for a kidney transplant. Since 2000, intrahepatic islet transplantation has proven efficacious in alleviating the burden of labile diabetes and preventing complications related to diabetes, whether or not a previous kidney transplant is present. Age, body-mass index, renal status, and cardiopulmonary status affect the choice between pancreas or islet transplantation. Access to transplantation is limited by the number of deceased donors and the necessity of immunosuppression. Future approaches might include alternative sources of islets (eg, xenogeneic tissue or human stem cells), extrahepatic sites of implantation (eg, omental, subcutaneous, or intramuscular), and induction of immune tolerance or encapsulation of islets.

Effects of Periodic Intensive Insulin Therapy: An Updated Review

Background

Traditional insulin treatment for diabetes mellitus with insulin administered subcutaneously yields nonpulsatile plasma insulin concentrations that represent a fraction of normal portal vein levels. Oral hypoglycemic medications result in the same lack of pulsatile insulin response to blood glucose levels. Intensive treatments of significant complications of diabetes are not recommended due to complicated multidrug regimens, significant weight gain, and the high risk of hypoglycemic complications. Consequently, advanced complications of diabetes do not have an effective treatment option because conventional therapy is not sufficient. Intensive insulin therapy (IIT) simulates normal pancreatic function by closely matching the periodicity and amplitude of insulin secretion in healthy subjects; however, the mechanisms involved with the observed improvement are not clearly understood.

Objective

The current review aims to analyze the pathophysiology of insulin secretion, discuss current therapies for the management of diabetes, provides an updates on the recent advancements of IIT, and proposes its mechanism of action.

Methods

A literature search on PubMed, MEDLINE, Embase, and CrossRef databases was performed on multiple key words regarding the history and current variations of pulsatile and IIT for diabetes treatment. Articles reporting the physiology of insulin secretion, advantages of pulsatile insulin delivery in patients with diabetes patients, efficacy and adverse effects of current conventional insulin therapies for the management of diabetes, benefits and shortcomings of pancreas and islet transplantation, or clinical trials on patients with diabetes treated with pulsed insulin therapy or advanced IIT were included for a qualitative analysis and categorized into the following topics: mechanism of insulin secretion in normal subjects and patients with diabetes and current therapies for the management of diabetes, including oral hypoglycemic agents, insulin therapy, pancreas and islet transplantation, pulsed insulin therapy, and advances in IIT.

Results

Our review of the literature shows that IIT improves the resolution of diabetic ulcers, neuropathy, and nephropathy, and reduces emergency room visits. The likely mechanism responsible for this improvement is increased insulin sensitivity from adipocytes, as well as increased insulin receptor expression.

Conclusions

Recent advancements show that IIT is an effective option for both type 1 diabetes mellitus and type 2 diabetes mellitus patient populations. This treatment resembles normal pancreatic function so closely that it has significantly reduced the effects of relatively common complications of diabetes in comparison to standard treatments. Thus, this new treatment is a promising advancement in the management of diabetes. (Curr Ther Res Clin Exp. 2019; 80:XXX–XXX).

Gray-scale, Doppler and contrast-enhanced ultrasound in pancreatic allograft surveillance: A systematic literature review

BACKGROUND

Gray scale ultrasound (US), Doppler and Contrast Enhanced Ultrasound (CEUS) represent important surveillance tools in the early post-operative period after pancreas transplantation (PTx), when complications are more common. This review summarizes the available evidence on their clinical application in this setting.

METHODS

We searched the Pub-Med database from inception to October 2018 for English literature on the clinical use of US, Doppler and CEUS in the post-PTx surveillance. Article selection was carried out according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria (PRISMA).

RESULTS

Twenty-nine articles concerning the clinical applications of US, Doppler and CEUS were identified, 13 of which, involving 264 patients, were focused on the sonographic findings in immunologic rejection, whereas 11 studies reporting on 887 patients were focused on post-PTx vascular complications. The remaining five articles, involving a total of 196 patients, described US or CEUS applied in the study of pancreatic morphology and texture to diagnose peri-graft fluids collections or to obtain experimental data on allograft endocrine function.

CONCLUSIONS

US, Doppler and CEUS have proven to be valuable assets in post-PTx follow up, thanks to the combination of their non-invasiveness with a high accuracy in the detection of early abnormalities, in particular regarding vascular complications. Preliminary experiences are directing towards functional research; however, future prospective trials are necessary to precisely correlate organ perfusion, early abnormalities and allograft function.

Oxygenation strategies for encapsulated islet and beta cell transplants

Human allogeneic islet transplantation (ITx) is emerging as a promising treatment option for qualified patients with type 1 diabetes. However, widespread clinical application of allogeneic ITx is hindered by two critical barriers: the need for systemic immunosuppression and the limited supply of human islet tissue. Biocompatible, retrievable immunoisolation devices containing glucose-responsive insulin-secreting tissue may address both critical barriers by enabling the more effective and efficient use of allogeneic islets without immunosuppression in the near-term, and ultimately the use of a cell source with a virtually unlimited supply, such as human stem cell-derived β-cells or xenogeneic (porcine) islets with minimal or no immunosuppression. However, even though encapsulation methods have been developed and immunoprotection has been successfully tested in small and large animal models and to a limited extent in proof-of-concept clinical studies, the effective use of encapsulation approaches to convincingly and consistently treat diabetes in humans has yet to be demonstrated. There is increasing consensus that inadequate oxygen supply is a major factor limiting their clinical translation and routine implementation. Poor oxygenation negatively affects cell viability and β-cell function, and the problem is exacerbated with the high-density seeding required for reasonably-sized clinical encapsulation devices. Approaches for enhanced oxygen delivery to encapsulated tissues in implantable devices are therefore being actively developed and tested. This review summarizes fundamental aspects of islet microarchitecture and β-cell physiology as well as encapsulation approaches highlighting the need for adequate oxygenation; it also evaluates existing and emerging approaches for enhanced oxygen delivery to encapsulation devices, particularly with the advent of β-cell sources from stem cells that may enable the large-scale application of this approach.

Who Should Be Considered for Islet Transplantation Alone?

PURPOSE OF REVIEW

Episodic hypoglycemia is an almost inevitable consequence of exogenous insulin treatment of type 1 diabetes, and in up to 30% of patients, this can lead to impaired awareness of hypoglycemia. This predisposes to recurrent severe hypoglycemia and has a huge impact on quality of life. Although many patients can get resolution of severe hypoglycemia through novel education and technology, some patients continue to have ongoing life-threatening hypoglycemia. Islet transplantation offers an alternative therapeutic option for these patients, in whom these conventional approaches have been unsuccessful. This review discusses the selection process of identifying suitable candidates based on recent clinical data.

RECENT FINDINGS

Results from studies of islet transplantation suggest the optimal recipient characteristics for successful islet transplantation include age >35 years, insulin requirements <1.0/kg, and weight < 85 kg. Islet transplantation can completely resolve hypoglycemia and near-normalize glucose levels, achieving insulin independence for a limited period of time in up to 40% of patients. The selection of appropriate candidates, optimizing donor selection, the use of an optimized protocol for islet cell extraction, and immunosuppression therapy have been proved to be the key criteria for a favorable outcome in islet transplantation.

Cost and clinical outcome of islet transplantation in Norway 2010-2015

Islet transplantation is a minimally invasive β-cell replacement strategy. Islet transplantation is a reimbursed treatment in Norway. Here, we summarize the cost and clinical outcome of 31 islet transplantations performed at Oslo University Hospital (OUS) from January 2010 to June 2015. Patients were retrospectively divided into three groups. Thirteen patients received either one or two islet transplantation alone (ITA), while five patients received islet transplantation after previous solid organ transplantation. For the group receiving 2 ITA, Kaplan-Meier estimates show an insulin independence of 20% more than 4 years after their last transplantation. An estimated 70% maintain at least partial graft function, defined as fasting C-peptide >0.1 nmol L^-1 , and 47% maintain a HbA1c below 6.5% or 2 percent points lower than before ITA. For all groups combined, we estimate that 44% of the patients have a 50% reduction in insulin requirement 4 years after the initial islet transplantation. The average cost for an islet transplantation procedure was 347 297±60 588 NOK, or 35 424±6182 EUR, of which isolation expenses represent 34%. We hereby add to the common pool of growing experience with islet transplantation and also describe the cost of the treatment at our center.

Beta-cell replacement therapy: current outcomes and future landscape

PURPOSE OF REVIEW

This article provides a summary of the current outcomes of β-cell replacement strategies, an algorithm for choosing a specific modality while highlighting associated advantages and disadvantages, and outlines remaining challenges and areas of active investigation in β-cell replacement therapy.

RECENT FINDINGS

The most recent reports of islet cell allotransplantation have shown improvements over previous eras and now rival some outcomes of pancreas alone transplantation. Active areas of investigation are focused on improving techniques for islet isolation, graft monitoring, and managing challenges posed by the innate and alloimmune systems.

SUMMARY

Patients with insulin-dependent diabetes who continue to experience life threatening hypoglycemia despite maximal medical management can benefit from β-cell replacement. Emerging nontransplant technologies have not provided a physiologic euglycemic state to the extent offered by transplantation. Islet transplantation eliminates hypoglycemic episodes/unawareness, facilitates normalization of hemoglobin A1c (HbA1c), decreases microvascular disease progression, and improves quality of life for patients with problematic diabetes. Mid- and long-term outcomes of islet transplantation performed at expert centers approximate those of registry reports of solitary pancreas transplant, whereas the complication profile is quite favorable.

A Comparative Analysis of the Safety, Efficacy, and Cost of Islet Versus Pancreas Transplantation in Nonuremic Patients With Type 1 Diabetes

Few current studies compare the outcomes of islet transplantation alone (ITA) and pancreas transplantation alone (PTA) for type 1 diabetes (T1D). We examined these two beta cell replacement therapies in nonuremic patients with T1D with respect to safety, graft function and cost. Sequential patients received PTA (n = 15) or ITA (n = 10) at our institution. Assessments of graft function included duration of insulin independence; glycemic control, as measured by hemoglobin A1c; and elimination of severe hypoglycemia. Cost analysis included all normalized costs associated with transplantation and inpatient management. ITA patients received one (n = 6) or two (n = 4) islet transplants. Mean duration of insulin independence in this group was 35 mo; 90% were independent at 1 year, and 70% were independent at 3 years. Mean duration of insulin independence in PTA was 55 mo; 93% were insulin independent at 1 year, and 64% were independent at 3 years. Glycemic control was comparable in all patients with functioning grafts, as were overall costs ($138 872 for ITA, $134 748 for PTA). We conclude that with advances in islet isolation and posttransplant management, ITA can produce outcomes similar to PTA and represents a clinically viable option to achieve long-term insulin independence in selected patients with T1D.

Cell rearrangement in transplanted human islets

The major feature of the human pancreatic islet architecture is the organization of endocrine cells into clusters comprising central β cells and peripheral α cells surrounded by vasculature. To have an insight into the mechanisms that govern this unique islet architecture, islet cells were isolated, and reaggregation of α and β cells into islet-like structures (pseudoislets) after culture or transplantation into mice was studied by immunohistology. The pseudoislets formed in culture displayed an unusual cell arrangement, contrasting with the transplanted pseudoislets, which exhibited a cell arrangement similar to that observed in native pancreatic islet subunits. The pattern of revascularization and the distribution of extracellular matrix around transplanted pseudoislets were alike to those observed in native pancreatic islets. This organization of transplanted pseudoislets occurred also when revascularization was abolished by treating mice with an anti-VEGF antibody, but not when contact with extracellular matrix was prevented by encapsulation of pseudoislets within alginate hydrogel. These results indicate that the maintenance of islet cell arrangement is dependent on in vivo features such as extracellular matrix but independent of vascularization.

Pancreas After Islet Transplantation: A First Report of the International Pancreas Transplant Registry

Pancreas after islet (PAI) transplantation is a treatment option for patients seeking insulin independence through a whole-organ transplant after a failed cellular transplant. This report from the International Pancreas Transplant Registry (IPTR) and the United Network for Organ Sharing (UNOS) studied PAI transplant outcomes over a 10-year time period. Forty recipients of a failed alloislet transplant subsequently underwent pancreas transplant alone (50%), pancreas after previous kidney transplant (22.5%), or simultaneous pancreas and kidney (SPK) transplant (27.5%). Graft and patient survival rates were not statistically significantly different compared with matched primary pancreas transplants. Regardless of the recipient category, overall 1- and 5-year PAI patient survival rates for all 40 cases were 97% and 83%, respectively; graft survival rates were 84% and 65%, respectively. A failed previous islet transplant had no negative impact on kidney graft survival in the SPK category: It was the same as for primary SPK transplants. According to this IPTR/UNOS analysis, a PAI transplant is a safe procedure with low recipient mortality, high graft-function rates in both the short and long term and excellent kidney graft outcomes. Patients with a failed islet transplant should know about this alternative in their quest for insulin independence through transplantation.

MR Imaging Monitoring of Iron-Labeled Pancreatic Islets in a Small Series of Patients: Islet Fate in Successful, Unsuccessful, and Autotransplantation

Islet transplantation is one of the most promising and effective therapies for restoring normoglycemia in type 1 diabetes (T1D) patients, but islet engraftment is one of the main obstacles hampering long-term success. Monitoring graft loss, caused either by immunological or nonimmunological events, occurring in the first phase after transplantation and at later stages of a patient's life is a very important issue. Among the imaging approaches previously applied, magnetic resonance imaging (MRI) monitoring of islet fate following labeling with superparamagnetic iron oxide agents yielded promising results. The aim of this study was to translate into patients the method of islet labeling and MRI monitoring developed in our preclinical setting and to compare imaging results with graft clinical outcome. Three T1D patients and one nondiabetic patient undergoing autotransplantation following subtotal pancreatectomy received Endorem®-labeled islets. Patients were monitored by MRI and metabolically (HbA1c, exogenous insulin requirement, and C-peptide, TEF) at 1, 3, and 7 days following transplantation and once a month up to 10 months. Labeled transplanted islets appeared as hypointense areas scattered within the liver parenchyma, whose absolute number at 24 h after transplantation reflected the labeling efficiency. In patients #1 and #3 with good midterm graft function, MRI follow-up showed an important early loss of hypointense spots followed by a slow and progressive disappearance at later timepoints. Graft loss of function in patient #2 4 weeks after transplantation was associated with the complete disappearance of all hypointense signals. The autotransplanted patient, stably insulin free, showed no significant signal reduction during the first 3 days, followed by loss of spots similar to a patient with good midterm graft function. These results suggest that MRI monitoring of islet transplantation at early time points could represent a meaningful readout for helping in predicting transplant failure or success, but its relevance for mid/long-term islet function assessment appears evanescent.

Pancreas Islet Transplantation for Patients With Type 1 Diabetes Mellitus: A Clinical Evidence Review

BACKGROUND

Type 1 diabetes mellitus is caused by the autoimmune destruction of pancreatic beta (β) cells, resulting in severe insulin deficiency. Islet transplantation is a β-cell replacement therapeutic option that aims to restore glycemic control in patients with type 1 diabetes. The objective of this study was to determine the clinical effectiveness of islet transplantation in patients with type 1 diabetes, with or without kidney disease.

METHODS

We conducted a systematic review of the literature on islet transplantation for type 1 diabetes, including relevant health technology assessments, systematic reviews, meta-analyses, and observational studies. We used a two-step process: first, we searched for systematic reviews and health technology assessments; second, we searched primary studies to update the chosen health technology assessment. The Assessment of Multiple Systematic Reviews measurement tool was used to examine the methodological quality of the systematic reviews and health technology assessments. We assessed the quality of the body of evidence and the risk of bias according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria.

RESULTS

Our searched yielded 1,354 citations. One health technology assessment, 11 additional observational studies to update the health technology assessment, one registry report, and four guidelines were included; the observational studies examined islet transplantation alone, islet-after-kidney transplantation, and simultaneous islet-kidney transplantation. In general, low to very low quality of evidence exists for islet transplantation in patients with type 1 diabetes with difficult-to-control blood glucose levels, with or without kidney disease, for these outcomes: health-related quality of life, secondary complications of diabetes, glycemic control, and adverse events. However, high quality of evidence exists for the specific glycemic control outcome of insulin independence compared with intensive insulin therapy. For patients without kidney disease, islet transplantation improves glycemic control and diabetic complications for patients with type 1 diabetes when compared with intensive insulin therapy. However, results for health-related quality of life outcomes were mixed, and adverse events were increased compared with intensive insulin therapy. For patients with type 1 diabetes with kidney disease, islet-after-kidney transplantation or simultaneous islet-kidney transplantation also improved glycemic control and secondary diabetic complications, although the evidence was more limited for this patient group. Compared with intensive insulin therapy, adverse events for islet-after-kidney transplantation or simultaneous islet-kidney transplantation were increased, but were in general less severe than with whole pancreas transplantation.

CONCLUSIONS

For patients with type 1 diabetes with difficult-to-control blood glucose levels, islet transplantation may be a beneficial β-cell replacement therapy to improve glycemic control and secondary complications of diabetes. However, there is uncertainty in the estimates of effectiveness because of the generally low to very low quality of evidence for all outcomes of interest.

Glycemic Control in Simultaneous Islet-Kidney Versus Pancreas-Kidney Transplantation in Type 1 Diabetes: A Prospective 13-Year Follow-up

OBJECTIVE

In patients with type 1 diabetes and end-stage renal disease, combined transplantation of a kidney together with a pancreas or isolated pancreatic islets are options to improve glycemic control. The aim of this study was to compare their long-term outcome with regard to metabolic control and surgical complication rate, as well as function of the transplanted kidney.

RESEARCH DESIGN AND METHODS

We conducted a prospective cohort study in consecutive patients receiving either a pancreas or islet transplant simultaneously with or after kidney transplantation (simultaneous pancreas-kidney [SPK]/pancreas-after-kidney [PAK] or simultaneous islet-kidney [SIK]/islet-after-kidney [IAK] transplantation).

RESULTS

Ninety-four patients who had undergone SPK/PAK transplantation were compared with 38 patients who had undergone SIK/IAK transplantation over a period of up to 13 years. HbA1c levels declined from 7.8 ± 1.3% (62 ± 14 mmol/mol) to 5.9 ± 1.1% (41 ± 12 mmol/mol), and from 8.0 ± 1.3% (64 ± 14 mmol/mol) to 6.5 ± 1.1% (48 ± 12 mmol/mol), respectively, in the SPK/PAK and SIK/IAK groups (P < 0.001 for both) and remained stable during follow-up, despite a reduction in the rate of severe hypoglycemia by >90%. The 5-year insulin independence rate was higher in the SPK/PAK group (73.6 vs. 9.3% in the SIK/IAK group), as was the rate of relaparotomy after transplantation (41.5 vs. 10.5% in the SIK/IAK group). There was no difference in the rate of kidney function decline.

CONCLUSIONS

During a long-term follow-up, SPK/PAK transplantation as well as SIK/IAK transplantation resulted in a sustained improvement of glycemic control with a slightly higher glycated hemoglobin level in the SIK/IAK group. While insulin independence is more common in whole-organ pancreas recipients, islet transplantation can be conducted with a much lower surgical complication rate and no difference in kidney function decline.

Clinical results of islet transplantation

Islet transplantation is considered an advanced therapy in the treatment of type-1 diabetes, with a progressive improvement of clinical results as seen in the Collaborative Islet Transplant Registry (CITR) report. It is an accepted method for the stabilization of frequent hypoglycemia, or severe glycemic lability, in patients with hypoglycemic unawareness, poor diabetic control, or a resistance to intensive insulin-based therapies. Worldwide data confirm a positive trend in this field, with the integrated management of pivotal factors: adequate islet mass, immunosuppressive protocols, additional anti-inflammatory therapy, and pre-transplant allo-immunity assessment. Insulin independence has been observed in several clinical trials with different rate, ranging 100-65% of patients; the maintenance of this condition during the follow-up progressively decreased, actually arranged on 44% 3 years after the last infusion, according to data reported from the CITR. Successful duration is progressively increasing, with ≥13 years being the longest reported insulin-free condition on record. The immediate results of functioning islet transplantation are an improvement in hypoglycemic awareness and a reduction in the glycated hemoglobin level. Furthermore, many studies have shown its influence on the chronic complications of diabetes, such as peripheral neuropathy, retinopathy, and macroangiopathy. Pre-transplant nephropathy remains an exclusion criterion as immunosuppressive therapy can exacerbate kidney-function deterioration. The problems linked to immunosuppression following islet transplantation for the treatment of type-1 diabetes need to be considered in order to achieve the correct risk/benefit ratio for each patient.

Human pancreatic islet transplantation: an update and description of the establishment of a pancreatic islet isolation laboratory

Type 1 diabetes mellitus (T1DM) is associated with chronic complications that lead to high morbidity and mortality rates in young adults of productive age. Intensive insulin therapy has been able to reduce the likelihood of the development of chronic diabetes complications. However, this treatment is still associated with an increased incidence of hypoglycemia. In patients with "brittle T1DM", who have severe hypoglycemia without adrenergic symptoms (hypoglycemia unawareness), islet transplantation may be a therapeutic option to restore both insulin secretion and hypoglycemic perception. The Edmonton group demonstrated that most patients who received islet infusions from more than one donor and were treated with steroid-free immunosuppressive drugs displayed a considerable decline in the initial insulin independence rates at eight years following the transplantation, but showed permanent C-peptide secretion, which facilitated glycemic control and protected patients against hypoglycemic episodes. Recently, data published by the Collaborative Islet Transplant Registry (CITR) has revealed that approximately 50% of the patients who undergo islet transplantation are insulin independent after a 3-year follow-up. Therefore, islet transplantation is able to successfully decrease plasma glucose and HbA1c levels, the occurrence of severe hypoglycemia, and improve patient quality of life. The goal of this paper was to review the human islet isolation and transplantation processes, and to describe the establishment of a human islet isolation laboratory at the Endocrine Division of the Hospital de Clínicas de Porto Alegre - Rio Grande do Sul, Brazil.

Current progress in xenotransplantation and organ bioengineering

Organ transplantation represents a unique method of treatment to cure people with end-stage organ failure. Since the first successful organ transplant in 1954, the field of transplantation has made great strides forward. However, despite the ability to transform and save lives, transplant surgery is still faced with a fundamental problem the number of people requiring organ transplants is simply higher than the number of organs available. To put this in stark perspective, because of this critical organ shortage 18 people every day in the United States alone die on a transplant waiting list (U.S. Department of Health & Human Services, http://organdonor.gov/about/data.html). To address this problem, attempts have been made to increase the organ supply through xenotransplantation and more recently, bioengineering. Here we trace the development of both fields, discuss their current status and highlight limitations going forward. Ultimately, lessons learned in each field may prove widely applicable and lead to the successful development of xenografts, bioengineered constructs, and bioengineered xeno-organs, thereby increasing the supply of organs for transplantation.

Novel T-cell inhibiting peptides delay the onset of Type 1 diabetes in non-obese diabetic mice

The aim of this study was to investigate the effectiveness of immunomodulatory peptides in preventing the spontaneous onset of Type 1 diabetes in NOD mice. Two such peptides, CP and C1, were injected intraperitoneally in NOD mice three times a week starting at two different time points, nine weeks and 11 weeks of age, and blood sugar levels monitored for the development of diabetes. CP was shown to be effective in delaying the onset of diabetes compared to control (P = 0.006). The timing of peptide administration was crucial since delay in treatment did not prevent the onset of diabetes (nine weeks versus 11 weeks of age). C1 was effective in delaying the onset of Type 1 diabetes with borderline significance when given at week 11 (P = 0.05). These findings confirm the efficacy of these peptides in the prevention and possible treatment for Type 1 diabetes and thereby create new opportunities for genetic manipulation.

Treating diabetes with islet transplantation: lessons from the past decade in Lille

Type 1 diabetes (T1D) is due to the loss of both beta-cell insulin secretion and glucose sensing, leading to glucose variability and a lack of predictability, a daily issue for patients. Guidelines for the treatment of T1D have become stricter as results from the Diabetes Control and Complications Trial (DCCT) demonstrated the close relationship between microangiopathy and HbA1c levels. In this regard, glucometers, ambulatory continuous glucose monitoring, and subcutaneous and intraperitoneal pumps have been major developments in the management of glucose imbalance. Besides this technological approach, islet transplantation (IT) has emerged as an acceptable safe procedure with results that continue to improve. Research in the last decade of the 20th century focused on the feasibility of islet isolation and transplantation and, since 2000, the success and reproducibility of the Edmonton protocol have been proven, and the mid-term (5-year) benefit-risk ratio evaluated. Currently, a 5-year 50% rate of insulin independence can be expected, with stabilization of microangiopathy and macroangiopathy, but the possible side-effects of immunosuppressants, limited availability of islets and still limited duration of insulin independence restrict the procedure to cases of brittle diabetes in patients who are not overweight or have no associated insulin resistance. However, various prognostic factors have been identified that may extend islet graft survival and reduce the number of islet injections required; these include graft quality, autoimmunity, immunosuppressant regimen and non-specific inflammatory reactions. Finally, alternative injection sites and unlimited sources of islets are likely to make IT a routine procedure in the future.

The allocation of pancreas allografts on donor age and duration of intensive care unit stay: the experience of the North Italy Transplant program

Starting in 2011, the North Italy Transplant program (NITp) has based on the allocation of pancreas allografts on donor age and duration of intensive care unit (ICU) stay, but not on donor weight or BMI. We analyzed the detailed allocation protocols of all NITp pancreas donors (2011-2012; n = 433). Outcome measures included donor characteristics and pancreas loss reasons during the allocation process. Twenty-three percent of the 433 pancreases offered for allocation were transplanted. Younger age, shorter ICU stay, traumatic brain death, and higher eGFR were predictors of pancreas transplant, either as vascularized organ or as islets. Among pancreas allografts offered to vascularized organ programs, 35% were indeed transplanted, and younger donor age was the only predictor of transplant. The most common reasons for pancreas withdrawal from the allocation process were donor-related factors. Among pancreas offered to islet programs, 48% were processed, but only 14.2% were indeed transplanted, with unsuccessful isolation being the most common reason for pancreas loss. Younger donor age and higher BMI were predictors of islet allograft transplant. The current allocation strategy has allowed an equal distribution of pancreas allografts between programs for either vascularized organ or islet transplant. The high rate of discarded organs remained an unresolved issue.

Islet transplantation stabilizes hemostatic abnormalities and cerebral metabolism in individuals with type 1 diabetes

OBJECTIVE Islets after kidney transplantation have been shown to positively affect the quality of life of individuals with type 1 diabetes (T1D) by reducing the burden of diabetes complications, but fewer data are available for islet transplantation alone (ITA). The aim of this study was to assess whether ITA has a positive impact on hemostatic and cerebral abnormalities in individuals with T1D. RESEARCH DESIGN AND METHODS Prothrombotic factors, platelet function/ultrastructure, and cerebral morphology, metabolism, and function have been investigated over a 15-month follow-up period using ELISA/electron microscopy and magnetic resonance imaging, nuclear magnetic resonance spectroscopy, and neuropsychological evaluation (Profile of Mood States test and paced auditory serial addition test) in 22 individuals with T1D who underwent ITA (n = 12) or remained on the waiting list (n = 10). Patients were homogeneous with regard to metabolic criteria, hemostatic parameters, and cerebral morphology/metabolism/function at the time of enrollment on the waiting list. RESULTS At the 15-month follow-up, the group undergoing ITA, but not individuals with T1D who remained on the waiting list, showed 1) improved glucose metabolism; 2) near-normal platelet activation and prothrombotic factor levels; 3) near-normal cerebral metabolism and function; and 4) a near-normal neuropsychological test. CONCLUSIONS ITA, despite immunosuppressive therapy, is associated with a near-normalization of hemostatic and cerebral abnormalities.

Impact of islet size on pancreatic islet transplantation and potential interventions to improve outcome

Better results have been recently reported in clinical pancreatic islet transplantation (ITX) due mostly to improved isolation techniques and immunosuppression; however, some limitations still exist. It is known that following transplantation, 30% to 60% of the islets are lost. In our study, we have investigated 1) the role of size as a factor affecting islet engraftment and 2) potential procedural manipulations to increase the number of smaller functional islets that can be transplanted. C57/BL10 mice were used as donors and recipients in a syngeneic islet transplant model. Isolated islets were divided by size (large, >300 μm; medium 150-300 μm; small, <150 μm). Each size was transplanted in chemically induced diabetic mice as full (600 IEQ), suboptimal (400 IEQ), and marginal mass (200 IEQ). Control animals received all size islets. Engraftment was defined as reversal of diabetes by day 7 posttransplantation. When the superiority of smaller islets was observed, strategies of overdigestion and fragmentation were adopted during islet isolation in the attempt to reduce islet size and improve engraftment. Smaller islets were significantly superior in engraftment compared to medium, large, and control (all sizes) groups. This was more evident when marginal mass data were compared. In all masses, success decreased as islet size increased. Once islets were engrafted, functionality was not affected by size. When larger islets were fragmented, a significant decrease in islet functionality was observed. On the contrary, if pancreata were slightly overdigested, although not as successful as small naive islets, an increase in engraftment was observed when compared to the control group. In conclusion, smaller islets are superior in engraftment following islet transplantation. Fragmentation has a deleterious effect on islet engraftment. Islet isolations can be performed by reducing islet size with slight overdigestion, and it can be safely adopted to improve clinical outcome.

The current state of pancreas transplantation

For many patients with type 1 diabetes mellitus and selected patients with type 2 diabetes mellitus, a successful pancreas transplant is the only definitive long-term treatment that both restores euglycaemia without the risk of severe hypoglycaemia and prevents, halts or reverses secondary complications. These benefits come at the cost of major surgery and lifelong immunosuppression. Nevertheless, pancreas transplants are safe and effective, with patient survival rates currently >95% at 1 year and >88% at 5 years; graft survival rates are almost 85% at 1 year and >60% at 5 years. The estimated half-life of a pancreas graft is now 7-14 years. The improvements in graft survival are attributable to considerable reductions in technical failures and in immunologic graft losses. Pancreas recipients have reduced mortality compared with waiting candidates or patients with diabetes mellitus who undergo a kidney transplant alone. Pancreas transplants should be more frequently offered to nonuraemic patients with brittle diabetes mellitus to prevent the development of secondary diabetic complications and to avoid the need for a kidney transplant. Although the results of islet transplantation have also improved, islet recipients rarely maintain long-term insulin independence despite the use of multiple organ donor pancreases. Pancreas transplants and islet transplants should be considered complementary, not mutually exclusive, procedures that are chosen on the basis of the individual patient's surgical risk.

Pancreas transplant alone: a procedure coming of age

The goal of this review is to highlight the significant improvements, over the past four decades, in outcomes after a pancreas transplant alone (PTA) in patients with brittle diabetes and recurrent episodes of hypoglycemia and/or hypoglycemic unawareness. A successful PTA-in contrast to intensive insulin regimens and insulin pumps-restores normoglycemia without the risk of hypoglycemia and prevents, halts, or reverses the development or progression of secondary diabetes complications. In this International Pancreas Transplant Registry (IPTR) analysis, we reviewed the records of 1,929 PTA recipients from December 1966 to December 2011. We computed graft survival rates according to the Kaplan-Meier method and used uni- and multivariate analyses. In the most recent era (January 2007-December 2011), patient survival rates were >95% at 1 year posttransplant and >90% at 5 years. Graft survival rates with tacrolimus-based maintenance therapy were 86% at 1 year and 69% at 3 years and with sirolimus, 94 and 84%. Graft survival rates have significantly improved owing to marked decreases in technical and immunologic graft failure rates (P < 0.05). As a result, the need for a subsequent kidney transplant has significantly decreased, over time, to only 6% at 5 years. With patient survival rates of almost 100% and graft survival rates of up to 94% at 1 year, a PTA is now a highly successful long-term option. It should be considered in nonuremic patients with brittle diabetes in order to achieve normoglycemia, to avoid hypoglycemia, and to prevent the development or progression of secondary diabetes complications.

Why is organ transplantation clinically important?

Solid organ transplantations save lives in patients affected by terminal organ failures and improve quality of life. Organ transplantations have gradually ameliorated in the last two decades and usually provide excellent results in children and young adults, and are increasingly challenged by the growing proportion of elderly transplant patients with comorbidities. Renal transplantation increases patient survival over dialysis, and lifesaving transplants are indispensible to treat patients with liver, heart, or lung irreversible diseases. Solid organ transplant programs activity has been steadily growing but is still far from global needs, with great differences among countries. Solid organ transplantations are essential for developed and mature health care systems.

Perceptions of diabetes in rural areas of Eastern Uganda

BACKGROUND

People diagnosed with diabetes mellitus are increasing in sub-Saharan Africa and prompt care seeking depends on perceptions of the illness.

OBJECTIVE

The objective was to explore perceptions of diabetes in rural areas.

METHOD

We conducted a qualitative, explorative and descriptive study in rural eastern Uganda. Eight focus group discussions with community members were conducted. Community members were presented with a story about a person with diabetes symptoms and their perceptions of the diagnosis and treatment elicited. Four focus group discussions with people with diabetes and seven key informant interviews with health workers were conducted. Respondents were asked how the community interpreted symptoms of diabetes, its causes and whether it was curable. Manifest content analysis was used.

RESULTS

Some respondents thought people with diabetes symptoms had HIV or were bewitched. Causes of diabetes mentioned included consuming too much fatty food. Some respondents thought diabetes is transmitted through air, sharing utensils with or sitting close to people with diabetes. Some respondents thought that diabetes could heal fast whilst others thought it was incurable.

CONCLUSION

Misdiagnosis may cause delay in seeking proper care. Preventive programmes could build on people's thinking that too much fatty food causes diabetes to promote diets with less fat. The perception of diabetes as a contagious disease leads to stigmatisation and affects treatment seeking. Seeing diabetes as curable could create patient expectations that may not be fulfilled in the management of diabetes. Rural communities would benefit from campaigns creating awareness of prevention, symptoms, diagnosis and management of diabetes.

25 YEARS OF THE RICORDI AUTOMATED METHOD FOR ISLET ISOLATION

The year 2013 marks the 25^th anniversary of the Automated Method for islet isolation. The dissociation chamber at the core of the Automated Method was developed by Dr. Camillo Ricordi in 1988 to enhance the disassembling of the pancreatic tissue via a combined enzymatic and mechanical digestion while preserving endocrine cell cluster integrity. This method has ever since become the gold standard for human and large animal pancreas processing, contributing to the success and increasing number of clinical trials of islet transplantation worldwide. Herein we offer an attempt to a comprehensive, yet unavoidably incomplete, historical review of the progress in the field of islet cell transplantation to restore beta-cell function in patients with diabetes.

Adipose tissue, hormones, and treatment of type 1 diabetes

Type 1 diabetes (T1D) is a serious disease with increasing incidence worldwide, with fatal consequences if untreated. Traditional therapies require direct or indirect insulin replacement, which involves numerous limitations and complications. While insulin is the major regulator of blood glucose, recent reports demonstrate the ability of several extra-pancreatic hormones to decrease blood glucose and improve metabolic homeostasis. Such hormones mainly include adipokines originating from adipose tissue (AT), while specific factors from the gut and liver also contribute to glucose homeostasis. Correction of T1D with adipokines is progressively becoming a realistic option, with the potential to overcome many problems associated with insulin replacement. Several recent studies demonstrate insulin-independent reversal or amelioration of T1D through administration of specific adipokines. Our recent work demonstrates the ability of healthy AT to compensate for the function of endocrine pancreas in long-term correction of T1D. This review discusses the potential of AT-related therapies for T1D as viable alternatives to insulin replacement.

Case report: gastrointestinal hemorrhage caused by a pancreas transplant arteriovenous fistula with large psuedoanuerysm 9 years after transplantation

Reported cases of arteriovenous fistulae in transplant recipients are uncommon. We present a case of an arteriovenous fistula associated with a large pseudoaneurysm in the root of the small bowel mesentery of a pancreas transplant. Uniquely, in our case, the arteriovenous fistula presented with an episode of gastrointestinal (GI) hemorrhage 9 years postoperatively. Radiographic imaging including coronal computed tomography angiogram and conventional angiogram demonstrated an arteriovenous fistula in the patient's pancreas transplant between the distal superior mesenteric artery (SMA) and superior mesenteric vein (SMV) with 6 cm aneurysmal dilatation. The tremendous flow in the fistula in the root of the graft small intestine mesentery led to graft duodenal mucosal congestion and lower GI hemorrhage. After successful embolization of the SMA-SMV fistula and pseudoaneurysm using interventional radiographic techniques, the arteriovenous fistula remained thrombosed. The patient had no further episodes of GI bleeding and her endoscopic evaluation was otherwise negative. The presence of arteriovenous fistulae and pseudoaneurysms in pancreas transplant recipients is uncommon, but has been previously documented. This case is further distinguished from previous reports by the notable 9-year interval between transplantation and the onset of hemorrhage. Historically, symptomatic vascular malformations have been associated with significant patient morbidity and mortality. Successful patient management involves timely and accurate diagnosis and intervention.