Type 2 diabetes: is pancreas transplantation an option?

Pancreas Transplantation in Minorities including Patients with a Type 2 Diabetes Phenotype

Background: Prior to year 2000, the majority of pancreas transplants (PTx) were performed as simultaneous pancreas-kidney transplants (SPKTs) in Caucasian adults with end stage renal failure secondary to type 1 diabetes mellitus (T1DM) who were middle-aged. In the new millennium, improving outcomes have led to expanded recipient selection that includes patients with a type 2 diabetes mellitus (T2DM) phenotype, which excessively affects minority populations. Methods: Using PubMed® to identify appropriate citations, we performed a literature review of PTx in minorities and in patients with a T2DM phenotype. Results: Mid-term outcomes with SPKT in patients with uremia and circulating C-peptide levels (T2DMphenotype) are comparable to those patients with T1DM although there may exist a selection bias in the former group. Excellent outcomes with SPKT suggests that the pathophysiology of T2DM is heterogeneous with elements consisting of both insulin deficiency and resistance related to beta-cell failure. As a result, increasing endogenous insulin (Cp) production following PTx may lead to freedom checking blood sugars or taking insulin, better metabolic counter-regulation, and improvements in quality of life and life expectancy compared to other available treatment options. Experience with solitary PTx for T2DM or in minorities is limited but largely mirrors the trends reported in SPKT. Conclusions: PTx is a viable treatment option in patients with pancreas endocrine failure who are selected appropriately regardless of diabetes type or recipient race. This review will summarize data that unconventional patient populations with insulin-requiring diabetes may gain value from PTx with an emphasis on contemporary experiences and appropriate selection in minorities in the new millennium.

Pancreas Transplantation in Black, Asian and Minority Ethnic Patients-Single Centre Experience in the UK

Ethnic disparities in the outcomes after simultaneous pancreas kidney (SPK) transplantation still exist. The influence of ethnicity on the outcomes of pancreas transplantation in the UK has not been reported and hence we aimed to investigate our cohort. A retrospective analysis of all pancreas transplant recipients (n = 171; Caucasians = 118/Black Asian Ethnic Minorities, BAME = 53) from 2006 to 2020 was done. The median follow-up was 80 months. Patient & pancreas graft survival, rejection rate, steroid free maintenance rate, HbA1c, weight gain, and the incidence of secondary diabetic complications post-transplant were compared between the groups. p < 0.003 was considered significant (corrected for multiple hypothesis testing). Immunosuppression consisted of alemtuzumab induction and steroid free maintenance with tacrolimus and mycophenolate mofetil. Pancreas graft & patient survival were equivalent in both the groups. BAME recipients had a higher prevalence of type-2 diabetes mellitus pre-transplant (BAME = 30.19% vs. Caucasians = 0.85%, p < 0.0001), and waited for a similar time to transplantation once waitlisted, although pre-emptive SPK transplantation rate was higher for Caucasian recipients (Caucasians = 78.5% vs. BAME = 0.85%, p < 0.0001). Despite equivalent rejections & steroid usage, BAME recipients gained more weight (BAME = 7.7% vs. Caucasians = 1.8%, p = 0.001), but had similar HbA1c (functioning grafts) at 3-,12-, 36-, and 60-months post-transplant.

Do pretransplant C-peptide levels predict outcomes following simultaneous pancreas-kidney transplantation? A matched case-control study

Following simultaneous pancreas-kidney transplantation (SPKT), survival outcomes are reported as equivalent in patients with detectable pretransplant C-peptide levels (Cp+) and a "type 2″ diabetes mellitus (DM) phenotype compared to type 1 (Cp negative [Cp-]) DM. We retrospectively compared 46 Cp+ patients pretransplant (≥2.0 ng/mL, mean 5.4 ng/mL) to 46 Cp- (level < 0.5 ng/mL) case controls matched for recipient age, gender, race, and transplant date. Early outcomes were comparable. Actual 5-year patient survival (91% versus 94%), kidney graft survival (69% versus 86%, p = .15), and pancreas graft survival (60% versus 86%, p = .03) rates were lower in Cp+ versus Cp- patients, respectively. The Cp+ group had more pancreas graft failures due to insulin resistance (13% Cp+ versus 0% Cp-, p = .026) or rejection (17% Cp+ versus 6.5% Cp-, p = .2). Post-transplant weight gain > 5 kg occurred in 72% of Cp+ versus 26% of Cp- patients (p = .0001). In patients with functioning grafts, mean one-year post-transplant HbA1c levels (5.0 Cp+ versus 5.2% Cp-) were comparable, whereas Cp levels were higher in Cp+ patients (5.0 Cp+ versus 2.6 ng/mL Cp-). In this matched case-control study, outcomes were inferior in Cp+ compared to Cp- patients following SPKT, with post-transplant weight gain, insulin resistance, and rejection as potential mitigating factors.

A comparative study of pancreas transplantation between type 1 and 2 diabetes mellitus

Background

Pancreas transplantation remains the best long-term treatment option to achieve physiological euglycemia and insulin independence in patients with labile diabetes mellitus (DM). It is widely accepted as an optimal procedure for type 1 DM (T1DM), but its application in type 2 DM (T2DM) is not unanimously acknowledged.

Methods

In total, 146 diabetes patients undergoing pancreas transplantation were included in this study. Clinical data and outcomes were compared between the T1DM and T2DM groups.

Results

Majority (93%) of the pancreas transplantations in T2DM were for uremic recipients. Complications occurred in 106 (73%) patients, including 70 (48%) with early complications before discharge and 79 (54%) with late complications during follow-up period. Overall, rejection of pancreas graft occurred in 37 (25%) patients. Total rejection rate in T2DM recipients was significantly lower than that in T1DM. The short- and long-term outcomes for endocrine function in terms of fasting blood sugar and hemoglobin A1c levels and graft survival rates are comparable between the T2DM and T1DM groups.

Conclusions

T2DM is not inferior to T1DM after pancreas transplantation in terms of surgical risks, immunological and endocrine outcomes, and graft survival rates. Therefore, pancreas transplantation could be an effective option to treat selected uremic T2DM patients without significant insulin resistance.

Simultaneous pancreas and kidney transplantation for end-stage kidney disease patients with type 2 diabetes mellitus: a systematic review and meta-analysis

PURPOSE

The indications for patients with type 2 diabetes mellitus (T2DM) combined with end-stage kidney disease (ESKD) undertaking simultaneous pancreas and kidney transplantation (SPK) remain an unresolved issue. This study aimed to systematically review the survival outcomes of SPK among T2DM-ESKD patients.

METHODS

Online databases including PubMed, MEDLINE, EMBASE, and the CENTRAL Library, CNKI, Chinese Biomedical Literature Database, and Wan-Fang database were used to locate the studies of ESKD patients with T2DM undertaking SPK up to May 2021. A third reviewer was consulted if there were disagreements. Data were analyzed with STATA (15.0).

RESULTS

Nine cohort studies were identified. The pooled 1-year, 3-year, and 5-year patient survival rates of patients with T2DM and ESKD after SPK were 98%, 95%, and 91% respectively. Comparing the treatment effect of SPK between type 1 diabetes mellitus (T1DM) and T2DM, the survival estimates were comparable. For T2DM patients, SPK had a survival advantage compared with KTA.

CONCLUSIONS

The synthesized clinical outcomes of T2DM patients with ESKD after SPK were relatively better than KTA, but a subset of T2DM-ESKD patients who would benefit the most from SPK was to be defined. PROSPERO registration number CRD42019118321. Date of registration: 14 Jan 2019 (retrospectively registered).

Lack of Improvement in Insulin Sensitivity After Pancreas Transplantation in Recipients With a High Level of Calcineurin Inhibitors

OBJECTIVES

This study aimed to assess posttransplant changes in insulin sensitivity and β-cell function of pancreas transplant recipients according to the type of diabetes mellitus (DM) and the pretransplant insulin sensitivity measured by the Matsuda Index (MI).

METHODS

We analyzed 60 patients who underwent pancreas transplantation and oral glucose tolerance test pretransplant and at 1 month posttransplant.

RESULTS

At 1 month posttransplant, insulin sensitivity did not show significant improvement; particularly, the MI was significantly lower after transplant in recipients with type 1 DM (T1DM) and those with pretransplant MI of 5 or greater. β-cell function was significantly improved after transplant in all recipients regardless of the type of DM and pretransplant MI values. Glucose control was significantly improved in recipients with T1DM and in all recipients regardless of the pretransplant MI values. Additional oral glucose tolerance test at 1 year posttransplant revealed that insulin sensitivity remained unimproved and β-cell function was higher compared with pretransplant. Glucose control had partially reverted to pretransplant levels in recipients with T1DM and those with pretransplant MI of 5 or greater.

CONCLUSIONS

Unlike β-cell function and glucose control, insulin sensitivity did not significantly improve until posttransplant 1 year after pancreas transplantation regardless of the type of DM or the degree of pretransplant insulin sensitivity.

Retrospective Analysis of Pancreas Transplants in Poland in Years 1998-2015

Transplantation of the pancreas is an established method for the treatment of complicated diabetes mellitus. As the numbers of diabetic patients increase so does the need for efficient treatment methods. Despite significant perioperative risk and complications related to immunosuppression, pancreas transplant remains the best therapeutic option for selected patients.

METHODS

The analysis was based on the comparison of characteristics of all organ donors and recipients in years 1998 to 2015. The collected data were divided into 2 periods to facilitate identification of populational changes.

RESULTS

The total number of pancreas transplants in Poland was 139 in years 1998 to 2006 and 268 in years 2007 to 2015. The largest differences revealed by the comparison of donor-related variables in both periods were those related to the doses of pressor amines, duration of circulatory arrest, and duration of stay at the intensive care unit. The critical finding consisted in the improvement of short-term survival of recipients and organs being observed in contrast to the surprising lack of improvement in long-term survival. Reduced likelihood of transplantation success was observed already in overweight patients (body mass index 25-29.99 kg/m²).

CONCLUSIONS

No significant changes were observed with regard to pancreas transplant outcomes over the period of many years. Transplantation success is determined by 1-year survival of the organ, and the therapeutic success is measured by long-term disease-free survival of the patient. In the era of rapid advances in numerous areas of medicine, the lack of significant extension of patient survival times warrants a closer look of our knowledge on pancreas transplants.

Short and long-term metabolic outcomes in patients with type 1 and type 2 diabetes receiving a simultaneous pancreas kidney allograft

BACKGROUND

In contrast to insulin-dependent type 1 diabetes mellitus (T1DM), the indication for Simultaneous pancreas-kidney transplantation (SPK) in patients with type 2 diabetes mellitus (T2DM) is still ambiguous and wisely Eurotransplant (ET) only granted transplant-permission in a selected group of patients. However, with regard to improvement of metabolic conditions SPK might still be a considerable treatment option for lean insulin dependent type 2 diabetics suffering from renal disease.

METHODS

Medical data (2001-2013) from all consecutive T1DM and T2DM patients who received a SPK or kidney transplant alone (KTA) at the University Hospital of Leipzig were analyzed. Donor, recipients and long-term endocrine, metabolic and graft outcomes were investigated for T1DM and T2DM-SPK recipients (transplanted upon a special request allocation by ET) and T2DM patients who received a KTA during the same period.

RESULTS

Eighty nine T1DM and 12 T2DM patients received a SPK and 26 T2DM patients received a KTA. Patient survival at 1 and 5 years was 89.9 and 88.8% for the T1DM group, 91.7 and 83.3% for the T2DM group, and 92.3 and 69.2% for the T2DM KTA group, respectively (p < 0.01). Actuarial pancreas graft survival for SPK recipients at 1 and 5 years was 83.1 and 78.7% for the T1DM group and 91.7 and 83.3% for the T2DM group, respectively (p = 0.71). Kidney allograft survival at 5 years was 79.8% for T1DM, 83.3% for T2DM, and 65.4% for T2DM KTA (p < 0.01). Delayed graft function (DGF) rate was significantly higher in type 2 diabetics received a KTA. Surgical, immunological and infectious complications showed similar results for T1DM and T2DM recipients after SPK transplant and KTA, respectively. With regard to the lipid profile, the mean high-density lipoprotein (HDL)- cholesterol levels were significantly higher in T1DM recipients compared to T2DM patients before transplantation (p = 0.02) and remained significantly during follow up period.

CONCLUSION

Our data demonstrate that with regard to metabolic function a selected group of patients with T2DM benefit from SPK transplantation. Consensus guidelines and further studies for SPK transplant indications in T2DM patients are still warranted.

Novel surgical technique and efficacy analysis of donor pancreas preparation without vascular reconstruction in pancreas transplantation

Objective

Because of the complicated blood supply and vascular structure of the pancreas, blood vessel reconstruction and reshaping are generally required during pancreas transplantation. We modified the vascular preparation procedure for the donor pancreas (i.e., no vascular reconstruction was performed) based on experiences in our department and in other domestic and international transplantation centers.

Methods

Twelve donor pancreas preparations without vascular reconstruction were performed. The patch (Carrel patch), celiac trunk, and superior mesenteric artery were preserved as arterial inflow channels for the donor pancreas. The common hepatic artery and the gastroduodenal artery were transected at a site 0.5 cm away from the bifurcation. The bifurcated portion was preserved for the donor liver. The stumps of the gastroduodenal artery and common hepatic artery were then ligated. The portal vein was transected in the middle of the hepatoduodenal ligament during separation of the liver and pancreas. The partial portal vein preserved with the pancreas was used as the outflow channel of the donor pancreas.

Results

The transplanted pancreas functioned well in the recipients, and no vascular complications were reported.

Conclusion

The overall efficacy of pancreas transplantation without vascular reconstruction has been improved.

Pancreas transplantation in type 2 diabetes: expanding the criteria

PURPOSE OF REVIEW

Pancreas transplantation in type 2 diabetes mellitus (T2DM) candidates remains disproportionately lower than in type 1 diabetes mellitus (T1DM); however, outcomes in carefully selected patients mirrors that of T1DM. Despite the 2014 United Network for Organ Sharing (UNOS) eligibility criteria for simultaneous pancreas/kidney transplant (SPK) transplantation in T2DM patients, an expected increase in the number of transplants was not observed.

RECENT FINDINGS

In an updated International Pancreas and Transplant Registry (IPTR) analysis, 1514 primary deceased donor pancreas transplants were performed in T2DM recipients [1995-2015, SPK 88%, pancreas after kidney (PAK) 9%, pancreas transplant alone (PTA) 3%]. In contrast to the declining number of SPK transplants for T1DM, the number of primary SPK transplants in T2DM patients is increasing over time in the USA. Improvement over time was noted for T2DM SPK patient and graft survival, and the rate of technical failures decreased, paralleling similar overall trends for pancreas transplants in general. Long-term follow-up data of pancreas outcomes in C-peptide positive vs. negative demonstrate noninferior outcomes. BMI does not appear to impact outcomes in carefully selected T2DM candidates.

SUMMARY

The current UNOS regulations that currently limit access of T2DM to pancreas transplantation based on strict BMI criteria and C-peptide levels need to be liberated.

Simultaneous pancreas-kidney transplantation. Experience of the Doce de Octubre Hospital

INTRODUCTION

Simultaneous pancreas-kidney transplantation (SPKT) constitutes the therapy of choice for diabetes type1 or type2 associated with end-stage renal disease, because is the only proven method to restore normo-glicemic control in the diabetic patient.

METHODS

Retrospective and descriptive study of a series of 175 patients who underwent SPKT from March 1995 to April 2016. We analyze donor and recipient characteristics, perioperative variables and immunosuppression, post-transplant morbi-mortality, patient and graft survival, and risk factors related with patient and graft survival.

RESULTS

Median age of the donors was 28years and mean age of recipients was 38.8±7.3years, being 103 males and 72 females. Enteric drainage of the exocrine pancreas was performed in 113 patients and bladder drainage in 62. Regarding post-transplant complications, the overall rate of infections was 70.3%; graft pancreatitis 26.3%; intraabdominal bleeding 17.7%; graft thrombosis 12.6%; and overall pancreas graft rejection 10.9%. The causes of mortality were mainly cardiovascular and infectious complications. Patient survival at 1, 3 and 5-year were 95.4%, 93% and 92.4%, respectively, and pancreas graft survival at 1, 3 and 5-year were 81.6%, 77.9% y 72.3%, respectively.

CONCLUSIONS

In our 20-year experience of simultaneous pancreas-kidney transplantation, the morbidity rate, and 5-year patient and pancreas graft survivals were similar to those previously reported from the international pancreas transplant registries.

Long-term Metabolic Outcomes of Functioning Pancreas Transplants in Type 2 Diabetic Recipients

BACKGROUND

Limited data are available regarding the long-term metabolic outcomes of functioning pancreas transplants in patients with type 2 diabetes mellitus (T2DM).

METHODS

To compare the long-term effects of pancreas transplantation in terms of insulin resistance and β cell function, comparison of metabolic variables was performed between type 1 diabetes mellitus (T1DM) and T2DM patients from 1-month posttransplant to 5 years using generalized, linear-mixed models for repeated measures.

RESULTS

Among 217 consecutive patients who underwent pancreas transplantation at our center between August 2004 and January 2015, 193 patients (151 T1DM and 42 T2DM) were included in this study. Throughout the follow-up period, postoperative hemoglobin A1c did not differ significantly between T1DM and T2DM patients, and the levels were constantly below 6% (42 mmol/mol) until 5 years posttransplant, whereas C-peptide was significantly higher in T2DM (P = 0.014). There was no difference in fasting insulin, homeostasis model assessment (HOMA) of insulin resistance, HOMA β cell, or the insulinogenic index between the groups. Furthermore, fasting insulin and HOMA-insulin resistance steadily decreased in both groups during the follow-up period.

CONCLUSIONS

There was no significant difference in the insulin resistance or β-cell function after pancreas transplantation between T1DM and T2DM patients. We demonstrated that pancreas transplantation is capable of sustaining favorable endocrine functions for more than 5 years in T2DM recipients.

Challenges in pancreas transplantation

Whole-organ pancreas transplantation, either alone or combined with a kidney transplant, is the only definitive treatment for many patients with type 1 diabetes that restores normal glucose homoeostasis and insulin independence. Pancreas transplantation delays, or potentially prevents, secondary diabetes complications and is associated with improvement in patient survival when compared with either patients remaining on the waiting list or those receiving kidney transplant alone. Pancreas transplantation is safe and effective, with 1-year patient survival >97 % and graft survival rates of 85 % at 1 year and 76 % at 5 years in recent UK data. This review focuses on some current areas of interest in pancreas transplantation.

Biomarkers in pancreas transplant

PURPOSE OF REVIEW

The review analyzes the current biomarkers used in monitoring pancreas transplant, from the simple and time-tested, to more sophisticated, including markers of allo- and autoimmunity, that are likely to play a larger role in future studies.

RECENT FINDINGS

Evaluation of alloimmunity includes serum levels of donor-specific antibody, and, ultimately, pancreas transplant biopsies with C4d staining. Our center has focused on markers of autoimmunity, including assessment of autoantibodies and autoreactive T cells. We have found that conversion of autoantibodies (including GAD65, IA-2, and ZnT8), or the development of a new positive autoantibody, particularly ZnT8, are associated with type 1 diabetes (T1D) recurrence in the pancreas transplant. Autoreactive T cells have also been identified in the peripheral blood, pancreas transplant and peripancreas transplant-lymph nodes, that have the potential to mediate human β/islet cell destruction in vivo.

SUMMARY

The monitoring of pancreas transplant biomarkers, particularly those associated with autoimmunity, has led to new insights into the pathogenesis of T1D. Progress in the elucidation of mechanisms of autoimmunity may lead to novel therapeutic approaches to both T1D recurrence of the pancreas transplant and perhaps also new onset T1D.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 6: patient selection for pilot clinical trials of islet xenotransplantation

Patients in whom type 1 diabetes is complicated by impaired awareness of hypoglycemia and recurrent episodes of severe hypoglycemia are candidates for islet or pancreas transplantation if severe hypoglycemia persists after completion of a structured stepped care approach or a formalized medical optimization run-in period that provides access to hypoglycemia-specific education including behavioral therapies, insulin analogs, and diabetes technologies under the close supervision of a specialist hypoglycemia service. Patients with type 1 diabetes and end-stage renal failure who cannot meet clinically appropriate glycemic goals or continue to experience severe hypoglycemia after completion of a formalized medical optimization program under the guidance of an expert diabetes care team are candidates for islet or pancreas transplantation either simultaneously with or after a previous kidney transplant. Similarly, patients with type 2 diabetes and problematic hypoglycemia or renal failure who meet these criteria are considered candidates for islet replacement. Likewise, patients with pancreatectomy-induced diabetes in whom an islet autograft was not available or deemed inappropriate are candidates for islet or pancreas transplantation if extreme glycemic lability persists despite best medical therapy. To justify participation of these transplant candidates in early-phase trials of porcine islet cell products, lack of timely access to islet or pancreas allotransplantation due to allosensitization, high islet dose requirements, or other factors, or alternatively, a more favorable benefit-risk determination associated with the xenoislet than the alloislet or allopancreas transplant must be demonstrated. Additionally, in non-uremic xenoislet recipients, the risks associated with diabetes must be perceived to be more serious than the risks associated with the xenoislet product and the rejection prophylaxis, and in xenoislet recipients with renal failure, the xenoislet product and immunosuppression must not impact negatively on renal transplant outcomes. The most appropriate patient group for islet xenotransplantation trials will be defined by the specific characteristics of each investigational xenoislet product and related technologies applied for preventing rejection. Selecting recipients who are more likely to experience prolonged benefits associated with the islet xenograft will help these patients comply with lifelong monitoring and other public health measures.

Simultaneous pancreas and kidney transplantation: current trends and future directions

Purpose of review

Important trends are being observed in pancreas transplantation in the USA. We will describe recent trends in simultaneous pancreas kidney (SPK) transplantation related to immunosuppression, treatment of rejection, and transplantation for patients of advanced age and C-peptide positive diabetes.

Recent findings

Rates of pancreas transplantation have declined, despite improved pancreatic graft outcomes. Regarding immunosuppression, trends in SPK transplantation include T-cell depletion induction therapy, waning mammalian target of rapamycin inhibitor use and steroid use in greater than 50% of pancreas transplant recipients with few patients undergoing late steroid weaning. Rejection of the pancreas may be discordant with the kidney after SPK and there is a greater appreciation of antibody-mediated rejection of the pancreas allograft. De-novo donor-specific antibody without graft dysfunction remains an active area of study, and the treatment for this condition is unclear. SPKs are being performed with greater frequency in type 2 diabetes mellitus patients and in patients of advanced age, with exemplary results.

Summary

The current state of the art in SPK transplantation is yielding superb and improving results.