Reduction in carotid intima-media thickness after pancreatic islet transplantation in patients with type 1 diabetes

The Impact of Kidney/Pancreas Transplantation on Peripheral Arterial Disease

INTRODUCTION

It is unclear whether kidney/pancreas (KP) transplantation will prevent the progression of peripheral arterial disease (PAD) in patients with insulin dependent diabetes (IDDM) and end-stage renal disease. We sought to determine the pre- and posttransplant prevalence of symptomatic PAD and changes in carotid artery intima-media thickness (IMT) in KP recipients.

METHODS

In this single center study, outcomes were compared between KP recipients with and without a history of PAD. A subset of recipients underwent pre- and posttransplant IMT measurements.

RESULTS

Among the study group (N = 107), 18 (17%) recipients admitted to a pretransplant history of symptomatic PAD, comprised 11 foot infections and 7 amputations (5 minor and 2 major). Baseline characteristics of age, gender, race, years of diabetes, dialysis history, smoking history, years of hypertension, and history of coronary artery disease (CAD) were equivalent between PAD and non-PAD cohorts. At a median follow-up of 60 months (IQR: 28, 110), 16 (15%) KP recipients had suffered a PAD event. In multivariate analysis, a pretransplant history of PAD (hazard ratio [HR] 9.66, p < 0.001) and CAD (HR 3.33, p = 0.04) were independent predictors of posttransplant PAD events. Among a subset of 20 recipients (3 with PAD), mean IMT measurements pretransplant and at a median of 24 (range 18-24) months posttransplant, showed no evidence of disease progression.

CONCLUSION

Based on IMT measurements and clinical results, KP transplantation stabilized PAD in most patients, but did not alter outcomes of symptomatic PAD recipients. A pretransplant history of PAD and CAD was an independent predictor of posttransplant PAD events.

A scalable human islet 3D-culture platform maintains cell mass and function long-term for transplantation

Present-day islet culture methods provide short-term maintenance of cell viability and function, limiting access to islet transplantation. Attempts to lengthen culture intervals remain unsuccessful. A new method was developed to permit the long-term culture of islets. Human islets were embedded in polysaccharide 3D-hydrogel in cell culture inserts or gas-permeable chambers with serum-free CMRL 1066 supplemented media for up to 8 weeks. The long-term cultured islets maintained better morphology, cell mass, and viability at 4 weeks than islets in conventional suspension culture. In fact, islets cultured in the 3D-hydrogel retained β cell mass and function on par with freshly isolated islets in vitro and, when transplanted into diabetic mice, restored glucose balance similar to fresh islets. Using gas-permeable chambers, the 3D-hydrogel culture method was scaled up over 10-fold and maintained islet viability and function, although the cell mass recovery rate was 50%. Additional optimization of scale-up methods continues. If successful, this technology could afford flexibility and expand access to islet transplantation, especially single-donor islet-after-kidney transplantation.

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.

Felix dies natalis, insulin… ceterum autem censeo "beta is better"

One hundred years after its discovery, insulin remains the life-saving therapy for many patients with diabetes. It has been a 100-years-old success story thanks to the fact that insulin therapy has continuously integrated the knowledge developed over a century. In 1982, insulin becomes the first therapeutic protein to be produced using recombinant DNA technology. The first "mini" insulin pump and the first insulin pen become available in 1983 and 1985, respectively. In 1996, the first generation of insulin analogues were produced. In 1999, the first continuous glucose-monitoring device for reading interstitial glucose was approved by the FDA. In 2010s, the ultra-long action insulins were introduced. An equally exciting story developed in parallel. In 1966. Kelly et al. performed the first clinical pancreas transplant at the University of Minnesota, and now it is a well-established clinical option. First successful islet transplantations in humans were obtained in the late 1980s and 1990s. Their ability to consistently re-establish the endogenous insulin secretion was obtained in 2000s. More recently, the possibility to generate large numbers of functional human β cells from pluripotent stem cells was demonstrated, and the first clinical trial using stem cell-derived insulin producing cell was started in 2014. This year, the discovery of this life-saving hormone turns 100 years. This provides a unique opportunity not only to celebrate this extraordinary success story, but also to reflect on the limits of insulin therapy and renew the commitment of the scientific community to an insulin free world for our patients.

Glucose as a modifiable cause of atherosclerotic cardiovascular disease: Insights from type 1 diabetes and transplantation

Diabetes is a major risk factor for cardiovascular (CV) disease. In contrast to the clear benefits from treatments which reduce blood pressure and lipids, clinical trials targeting blood glucose have not shown clear CV benefits. Interventions to intensify glycemic control early in the course of diabetes may have benefits in long term observational studies (DCCT-EDIC/UKPDS), but may not be helpful if introduced late in the course of type 2 diabetes (ACCORD, ADVANCE, VA-DT). More recent CVOT in high risk subjects suggest that the benefits of SGLT2 and GLP1-RA are glucose-independent. Type 1 diabetes provides a "cleaner" model to study the links between glucose and cardiovascular disease. Abnormalities of glucose regulation in type 1 diabetes is not restricted to hyperglycemia, but includes glycemic variability and hypoglycemia. Increasingly the mechanisms linking glycemic variability and hypoglycemia as key mediators of cardiovascular complications are being understood. Furthermore, data from pancreas and islet transplantation showing reduced cardiovascular mortality and regression of intima-media thickness supports a causal role for glucose in the pathogenesis of atherosclerosis, but suggests that restoration of normal glucose regulation may be required to demonstrate substantial impact on CV risk accrued over decades of type 1 diabetes. Considering the limited organ supply and risks of immunosuppression, advances in biology (stem cell derived beta cells) or technology (automated insulin delivery systems) will be required to provide a scalable solution to deliver optimal glucose control and reduce CV risk for people with type 1 diabetes.

Assessment of Risks and Benefits of Beta Cell Replacement Versus Automated Insulin Delivery Systems for Type 1 Diabetes

PURPOSE OF REVIEW

Current approaches to insulin replacement in type 1 diabetes are unable to achieve optimal levels of glycemic control without substantial risk of hypoglycemia and substantial burden of self-management. Advances in biology and technology present beta cell replacement and automated insulin delivery as two alternative approaches. Here we discuss current and future prospects for the relative risks and benefits for biological and psychosocial outcomes from the perspective of researchers, clinicians, and persons living with diabetes.

RECENT FINDINGS

Beta cell replacement using pancreas or islet transplant can achieve insulin independence but requires immunosuppression. Although insulin independence may not be sustained, time in range of 80-90%, minimal glycemic variability and abolition of hypoglycemia is routine after islet transplantation. Clinical trials of potentially unlimited supply of stem cell-derived beta cells are showing promise. Automated insulin delivery (AID) systems can achieve 70-75% time in range, with reduced glycemic variability. Impatient with the pace of commercially available AID, users have developed their own algorithms which appear to be at least equivalent to systems developed within conventional regulatory frameworks. The importance of psychosocial factors and the preferences and values of persons living with diabetes are emerging as key elements on which therapies should be evaluated beyond their impact of biological outcomes. Biology or technology to deliver glucose dependent insulin secretion is associated with substantial improvements in glycemia and prevention of hypoglycemia while relieving much of the substantial burden of diabetes. Automated insulin delivery, currently, represents a more accessible bridge to a biologic cure that we expect future cellular therapies to deliver.

β-Cell and renal transplantation options for diabetes

Despite major advances in structured education, insulin delivery and glucose monitoring, diabetes self-management remains an unremitting challenge. Insulin therapy is inextricably linked to risk of dangerous hypoglycaemia and sustained hyperglycaemia remains a leading cause of renal failure. This review sets out to demystify transplantation for diabetes multidisciplinary teams, facilitating consideration and incorporation within holistic overall person-centred management. Deceased and living donor kidney, whole pancreas and isolated islet transplant procedures, indications and potential benefits are described, in addition to outcomes within the integrated UK transplant programme.

Ultrasound Assessment of Intima-media Thickness and Diameter of Carotid Arteries in Patients Undergoing Hemodialysis or Renal Transplantation

Renal transplant (RT) recipients have a high risk of developing cardiovascular diseases. However, the effects of renal transplantation on the development of arteriosclerosis have been controversial. The carotid intima-media thickness (СШТ) and diameter (CD) are important indicators of vascular remodeling and arteriosclerosis. In this study, 31 patients with hemodialysis (HD), 31 RT recipients and 84 age- and gender-matched control subjects were enrolled. Their CIMT and CD were measured by ultrasonic radiofrequency tracking, and the linear regression models and Z test were used to identify the progression of arteriosclerosis and the risk factors. Compared with HD group, RT group had significantly lower CIMT and CD. CIMT was found to be associated with age, body weight, resistance index and diastolic velocity, while CD was associated significantly with age, body weight, pulsatility index, end diastolic velocity and diastolic blood pressure (DBP), respectively. The correlation curves between CIMT and age showed the slopes of curves were decreased successively in control, RT and HD groups, and the curves between CD and age showed the slopes were decreased in order of RT > control > HD groups. It was concluded that CIMT and CD were significantly correlated with age in RT and moderately with age in HD patients. RT could reduce the progress of arteriosclerosis in patients with end-stage renal disease.

An improvement of carotid intima-media thickness and pulse wave velocity in renal transplant recipients

Background

Renal transplantation can significantly improve the quality of life of patients with end stage renal disease (ESRD) who would otherwise require dialysis. Renal transplant (RT) recipients have higher risks of cardiovascular disease compared with general population. The carotid intima-media thickness (CIMT) and pulse wave velocity (PWV) have been used as the important predicting factor of vascular arteriosclerosis. Therefore, this study was to investigate the improvement of carotid intima-media thickness and pulse wave velocity in renal transplant recipients.

Methods

Thirty-one patients with chronic kidney disease being treated with hemodialysis, 31 renal transplant recipients and 84 healthy control subjects were included to have the clinical evaluations and ultrasonography of bilateral carotid arteries. CIMT and PWV were independently measured by two ultrasonographers using the technique of ultrasonic radiofrequency tracking and correlated with arteriosclerosis risk factors. The progression of CIMT and PWV with age were analyzed by linear regression models, and the slopes of curves were compared using Z test.

Results

Compared with the patients on hemodialysis, the CIMT was significantly lower in renal transplant recipients and healthy control. The PWV were higher in hemodialysis patients and renal transplant recipients than that of the subjects in control group. The progression is CIMT positively corelated with age and cumulative duration in renal transplant recipients and hemodialysis patients. In both hemodialysis patients and renal transplant recipients, age and cumulative time on dialysis were all positively correlated with the increase of PWV as well.

Conclusions

Carotid intima-media thickness and pulse wave velocity is the predicting factors of developing arteriosclerosis, which were improved in renal transplant recipients.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0263-7) contains supplementary material, which is available to authorized users.

Coronary artery calcium may stabilize following islet cell transplantation in patients with type 1 diabetes

Islet cell transplantation can functionally cure type 1 diabetes and also improve carotid intima-media thickness. This study provides a preliminary description of changes in coronary artery calcium following islet transplantation, and associated factors. Coronary artery calcium was measured in 14 patients with type 1 diabetes (11 had measures both pre- and post-transplant [mean 2.3 years]) in the University of Illinois at Chicago's clinical trial. Multivariable mixed-effects linear regression of repeated measures was used to quantify calcium change and determine if this change was longitudinally associated with risk/protective factors. Thirteen of the patients were female, with mean baseline age, diabetes duration, and BMI of 47.6 and 28.7 years, and 23.1, respectively. Over half (57%) had detectable coronary artery calcium pre-transplant. Minimal change (0.39 mm³ /y, P = .02) occurred in coronary artery calcium levels pre- to post-transplant. No patient met criteria for calcium progression. Coronary artery calcium was positively associated with total and small VLDL particles (P ≤ .02), statin dose (P = .02), and urine albumin-to-creatinine ratio (P = .04) and negatively associated with free fatty acids (P = .03), total HDL (P = .03), large HDL particles (P = .005), and tacrolimus dose (P = .02). Islet transplant may stabilize coronary artery calcium, with optimal management of lipids and kidney function remaining key therapeutic targets. [NCT00679041].

Islet Microencapsulation: Strategies and Clinical Status in Diabetes

PURPOSE OF REVIEW

Type 1 diabetes mellitus (T1DM) is an autoimmune disease that results from the destruction of insulin-producing pancreatic β cells in the islets of Langerhans. Islet cell transplantation has become a successful therapy for specific patients with T1DM with hypoglycemic unawareness. The reversal of T1DM by islet transplantation is now performed at many major medical facilities throughout the world. However, many challenges must still be overcome in order to achieve continuous, long-term successful transplant outcomes. Two major obstacles to this therapy are a lack of islet cells for transplantation and the need for life-long immunosuppressive treatment. Microencapsulation is seen as a technology that can overcome both these limitations of islet cell transplantation. This review depicts the present state of microencapsulated islet transplantation.

RECENT FINDINGS

Microencapsulation can play a significant role in overcoming the need for immunosuppression and lack of donor islet cells. This review focuses on microencapsulation and the clinical status of the technology in combating T1DM.

Islet Cell Transplantation and Alternative Therapies

Even though type 2 diabetes rates plateaued, type 1 diabetes continues to increase. Pancreas transplantation is a treatment modality for patients who suffer hypoglycemic unawareness or complications from diabetes. Islet cell transplantation success rates have improved with modification and advances in isolation, transplantation, and new immunosuppression regimens. The new cell sources as well as delivery ways are explored and being tested in human trials.

Synergistic effect of PEGylation and pentoxifylline addition on immunoprotection of pancreatic islets

In this study, a method is proposed to reduce immunological response of immune system against Langerhans islets by PEGylation of islets combined with adjuvant therapy. For this purpose, the best composition for a mixture of succinimidyl valeric acid activated mPEG (mPEG-SVA) with different molecular weights (MWs) and for a mixture of succinimidyl carbonate activated mPEG (mPEG-SC) with different MWs was determined separately. Then, the effect of pentoxifylline (PTX) as an adjuvant drug on immunological response against PEGylated islets at best mPEG composition was studied. The extent of mPEGs reaction, the amount of interlukin-2 (IL-2) and perforin secretion, and the viability of lymphocytes and islets in homo and co-cultures in the presence of PTX at different concentrations were considered for the in vitro evaluation of the proposed method. It was found, that a mixture of mPEG-SVA with MWs of 10 and 5 kDa at a composition of 75 and 25%, respectively, was the best formulation. Also, the addition of PTX drug to co-culture medium increased the protection of PEGylated islets against immune system and a concentration of 75 μg mL^-1 of PTX was suitable for islet protection with no adverse effect on immune cells.

Portal Venous Interventions: State of the Art

In recent decades, there have been numerous advances in the management of liver cancer, cirrhosis, and diabetes mellitus. Although these diseases are wide ranging in their clinical manifestations, each can potentially be treated by exploiting the blood flow dynamics within the portal venous system, and in some cases, adding cellular therapies. To aid in the management of these disease states, minimally invasive transcatheter portal venous interventions have been developed to improve the safety of major hepatic resection, to reduce the untoward effects of sequelae from end-stage liver disease, and to minimize the requirement of exogenously administered insulin for patients with diabetes mellitus. This state of the art review therefore provides an overview of the most recent data and strategies for utilization of preoperative portal vein embolization, transjugular intrahepatic portosystemic shunt placement, balloon retrograde transvenous obliteration, and islet cell transplantation.

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.

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.

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.

Use of glucagon-like peptide-1 agonists to improve islet graft performance

Human islet transplantation is an effective and promising therapy for type I diabetes. However, long-term insulin independence is both difficult to achieve and inconsistent. De novo or early administration of incretin-based drugs is being explored for improving islet engraftment. In addition to its glucose-dependent insulinotropic effects, incretins also lower postprandial glucose excursion by inhibiting glucagon secretion, delaying gastric emptying, and can protect beta-cell function. Incretin therapy has so far proven clinically safe and tolerable with little hypoglycemic risk. The present review aims to highlight the new frontiers in research involving incretins from both in vitro and in vivo animal studies in the field of islet transplant. It also provides an overview of the current clinical status of incretin usage in islet transplantation in the management of type I diabetes.

Islet transplantation in type 1 diabetes: ongoing challenges, refined procedures, and long-term outcome

Remarkable progress has been made in islet transplantation over a span of 40 years. Once just an experimental curiosity in mice, this therapy has moved forward, and can now provide robust therapy for highly selected patients with type 1 diabetes (T1D), refractory to stabilization by other means. This progress could not have occurred without extensive dynamic international collaboration. Currently, 1,085 patients have undergone islet transplantation at 40 international sites since the Edmonton Protocol was reported in 2000 (752 allografts, 333 autografts), according to the Collaborative Islet Transplant Registry. The long-term results of islet transplantation in selected centers now match registry data of pancreas-alone transplantation, with 6 sites reporting five-year insulin independence rates ≥50%. Islet transplantation has been criticized for the use of multiple donor pancreas organs, but progress has also occurred in single-donor success, with 10 sites reporting increased single-donor engraftment. The next wave of innovative clinical trial interventions will address instant blood-mediated inflammatory reaction (IBMIR), apoptosis, and inflammation, and will translate into further marked improvements in single-donor success. Effective control of auto- and alloimmunity is the key to long-term islet function, and high-resolution cellular and antibody-based assays will add considerable precision to this process. Advances in immunosuppression, with new antibody-based targeting of costimulatory blockade and other T-B cellular signaling, will have further profound impact on the safety record of immunotherapy. Clinical trials will move forward shortly to test out new human stem cell derived islets, and in parallel trials will move forward, testing pig islets for compatibility in patients. Induction of immunological tolerance to self-islet antigens and to allografts is a difficult challenge, but potentially within our grasp.