Pancreas transplant alone as an independent risk factor for the development of renal failure: a retrospective study

Kidney disease in non-kidney solid organ transplantation

Kidney disease after non-kidney solid organ transplantation (NKSOT) is a common post-transplant complication associated with deleterious outcomes. Kidney disease, both acute kidney injury and chronic kidney disease (CKD) alike, emanates from multifactorial, summative pre-, peri- and post-transplant events. Several factors leading to kidney disease are shared amongst solid organ transplantation in addition to distinct mechanisms unique to individual transplant types. The aim of this review is to summarize the current literature describing kidney disease in NKSOT. We conducted a narrative review of pertinent studies on the subject, limiting our search to full text studies in the English language. Kidney disease after NKSOT is prevalent, particularly in intestinal and lung transplantation. Management strategies in the peri-operative and post-transplant periods including proteinuria management, calcineurin-inhibitor minimization/ sparing approaches, and nephrology referral can counteract CKD progression and/or aid in subsequent kidney after solid organ transplantation. Kidney disease after NKSOT is an important consideration in organ allocation practices, ethics of transplantation. Kidney disease after SOT is an incipient condition demanding further inquiry. While some truths have been revealed about this chronic disease, as we have aimed to describe in this review, continued multidisciplinary efforts are needed more than ever to combat this threat to patient and allograft survival.

Surgical options for glycaemic control in Type 1 diabetes

In recent years, bariatric surgery, also referred to as metabolic surgery, has become the most successful treatment option in those with Type 2 diabetes and obesity. There are some similarities in the pathological pathways in Type 1 and Type 2 diabetes, but the use of surgery in Type 1 diabetes remains unestablished and controversial. The treatment and management of Type 1 diabetes can be very challenging but recent advances in surgical interventions and technology has the potential to expand and optimize treatment options. This review discusses the current status of some surgical options available to people with Type 1 diabetes. These include implantable continuous glucose monitoring systems, continuous intraperitoneal insulin infusion pumps, closed-loop insulin delivery systems (also known as the artificial pancreas system) utilizing the latter two modalities of glucose monitoring and insulin delivery, and bariatric or metabolic surgery. Whole pancreas and islet transplantation are beyond the scope of this review but are briefly discussed.

Solid pancreas transplant: Pushing forward

Pancreas transplant has evolved significantly in recent years. It has now become a viable treatment option on type 1 diabetic patients with poorly controlled diabetes on conventional treatment, insulin intolerance, hypoglycaemia unawareness, brittle diabetes and/ or end-stage kidney disease. The purpose of this review is to provide an overview of pancreas transplant historical origins and current barriers to broader utilization of pancreata for transplant, with a focus on areas for future improvement to better pancreas transplant care. Donor pancreata remain underutilized; pancreatic allograft discard rates remain close to 30% in the United States. Donations after cardiac death (DCD) pancreata are seldom procured. Study groups from Europe and the United Kingdom showed that procurement professionalization and standardization of technique, as well as development of independent regional procurement teams might increase organ procurement efficiency, decrease discards and increase pancreatic allograft utilization. Pancreas transplant programs should consider exploring pancreas procurement opportunities on DCD and obese donors. Selected type 2 diabetics should be considered for pancreas transplant. Longer follow-up studies need to be performed in order to ascertain the long-term cardiovascular and quality of life benefits following pancreas transplant; the outcomes of which might eventually spearhead advocacy towards broader application of pancreas transplant among diabetics.

Protocol Duodenal Graft Biopsies Aid Pancreas Graft Surveillance

BACKGROUND

Histological evaluation of the pancreas graft is usually done on demand resulting in significant delays. This analysis reports on endoscopic protocol duodenal graft biopsies at regular intervals to determine feasibility, safety, and monitoring benefits.

METHODS

Protocol duodenal graft biopsies in 27 consecutive pancreas transplants (10 simultaneous pancreas kidney [SPK], 17 pancreas after kidney [PAK]) with a follow-up of a minimum of 12 months were performed at days 14, 30, 90, 180, 360, 430. University of Pittsburgh Medical Center classification for intestinal rejection was used. C4d staining was performed when antibody-mediated rejection was suspected.

RESULTS

Overall patient and pancreas graft survival was 100% and 93% at a mean follow-up of 2.8 years. One hundred sixty-seven endoscopic biopsy procedures were performed in 27 grafts without any complication. Biopsies revealed rejection in 3 (30%) SPK recipients and in 15 (82%) of PAK recipients as early as 14 days posttransplant. Two patients underwent PAK retransplantation diagnosed with acute rejection at day 180. All except 1 recipient being treated for rejection, showed histological improvement following antirejection treatment. Following transient treatment success, a total of 3 pancreas grafts were lost for immunological reason. One loss was immediate despite antirejection treatment, 1 secondary to nonresolving rejection at 7 months and the third due to recurrent rejection 15 months posttransplantation. Additionally, biopsies detected vascular (venous thrombosis) and overimmunosuppression (cytomegalovirus infection) complications.

CONCLUSIONS

Protocol graft duodenal biopsies detect complications after whole-organ pancreas transplantation, are useful in guiding therapy, and carry potential for improving outcome.

Successful pancreas transplantation alone is associated with excellent self-identified health score and glucose control: A retrospective study from a high-volume center in the United States

BACKGROUND

The benefits of pancreas transplantation are often difficult to measure. Here, we sought to determine the difference in quality of life for diabetic patients with and without a functional pancreas transplant alone (PTA).

METHODS

Pancreas transplant alone cases from 1993 to 2015 were considered. An IRB-approved survey inclusive of 15 questions spanning four domains was employed. Chi-square, Fisher's exact, and the T test were used where appropriate.

RESULTS

A total of 137 PTAs were performed during the study period. Of those reached (n = 32), 94% responded to the survey. Self-reported health scores were better (2.1 vs 3.0) for those with functioning pancreata (n = 18) vs those with a non-functional pancreas (n = 14), respectively (P = .036). Those with a functional pancreas had a HgbA1c of 5.3, vs 7.7 for a non-functional pancreas (P = .016). Significant hypoglycemia was reported in two of 18 with a functional transplant vs nine of 14 patients with a failed transplant (P = .003). Daily frustration with blood sugar affecting quality of life was significantly higher for patients with non-functional pancreas grafts (P < .001).

CONCLUSIONS

Pancreas transplantation alone is associated with better glucose control than insulin. In addition, recipients of functional PTAs have improved quality of life and better overall health scores than those with failed grafts.

Advances in pancreas transplantation

The potential to reverse diabetes has to be balanced against the morbidity of long-term immunosuppression associated with transplantation. For a patient with renal failure, the treatment of choice is often a simultaneous transplant of the pancreas and kidney or pancreas after kidney. For a patient with glycaemic instability, choices between a solid organ or islet transplant have to be weighed against benefits and risks of remaining on insulin. Results of simultaneous transplant of the pancreas and kidney transplantation are comparable to other solid-organ transplants, and there is evidence of improved quality of life and life expectancy. There is some evidence of benefit with respect to the progression of secondary diabetic complications in patients with functioning transplants for several years.

Pancreas Transplantation: Past, Present, Future

Diabetes is the pandemic disease of the modern era, with 10% of these patients having type 1 diabetes mellitus. Despite the prevalence, morbidities, and associated financial burden, treatment options have not changed since the introduction of injectable insulin. To date, over 40,000 pancreas transplants have been performed globally. It remains the only known method for restoring glycemic control and thus curing type 1 diabetes mellitus. The aim of this review is to bring pancreatic transplantation out of the specialist realm, informing practitioners about this important procedure, so that they feel better equipped to refer suitable patients for transplantation and manage, counsel, and support when encountering them within their own specialty. This study was a narrative review conducted in October 2015, with OVID interface searching EMBASE and MEDLINE databases, using Timeframe: Inception to October 2015. Articles were assessed for clinical relevance and most up-to-date content, with articles written in English as the only inclusion criterion. Other sources used included conference proceedings/presentations and unpublished data from our institution (Oxford Transplant Centre). Pancreatic transplantation is growing and has quickly become the gold standard of care for patients with type 1 diabetes mellitus and renal failure. Significant improvements in quality of life and life expectancy make pancreatic transplant a viable and economically feasible intervention. It remains the most effective method of establishing and maintaining euglycemia, halting and potentially reversing complications associated with diabetes.

Outcomes of Recipients With Pancreas Transplant Alone Who Develop End-Stage Renal Disease

Recipients of pancreas transplant alone (PTA) may be at increased risk for developing end-stage renal disease (ESRD). The survival experience of PTA recipients developing ESRD has not been described. Furthermore, the relative survival of these patients as compared to diabetics on chronic dialysis is unknown. We studied all adult PTA recipients from January 1, 1990 to September 1, 2008 using the Scientific Registry of Transplant Recipients. Each PTA recipient developing ESRD was matched to 10 diabetics on chronic dialysis from the United States Renal Data System. Cox proportional hazards models were fitted to determine the relation between ESRD and mortality among PTA recipients, and the relation between PTA and mortality among diabetics on chronic dialysis. There were 1597 PTA recipients in the study, of which 207 developed ESRD. Those with ESRD had a threefold increase in mortality versus those without (adjusted hazard ratio 3.28 [95% confidence interval: 2.27, 4.76]). There was no significant difference in the risk of death among PTA recipients with ESRD versus diabetics on dialysis. PTA recipients developing ESRD are three times more likely to die than PTA recipients without ESRD; however, the risk of death in these patients was similar to diabetics on chronic dialysis without PTA.

Tacrolimus for the prevention and treatment of rejection of solid organ transplants

Since its introduction to the antirejection armamentarium in 1994, tacrolimus has become the workhorse of transplant professionals for avoidance of solid organ transplant rejection. Not only does tacrolimus have potent immunosuppressive qualities that prevent rejection, but dosing is straight forward and it is generally well tolerated. However, in the long term, conditions such as calcineurin inhibitor nephrotoxicity can become a problem. A discussion of the compound, the pharmacokinetics, history, and current approved uses for tacrolimus is described. Indeed, tacrolimus is the most important drug for preventing transplant rejection. However, the increased appreciation for significant side effects, particularly in the long term, has led to building interest in new agents with different mechanisms of action and different metabolism.

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.

Diabetic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes

The incidence and prevalence of diabetes mellitus (DM) continue to grow markedly throughout the world, due primarily to the increase in type 2 DM (T2DM). Although improvements in DM and hypertension management have reduced the proportion of diabetic individuals who develop chronic kidney disease (CKD) and progress to end-stage renal disease (ESRD), the sheer increase in people developing DM will have a major impact on dialysis and transplant needs. This KDIGO conference addressed a number of controversial areas in the management of DM patients with CKD, including aspects of screening for CKD with measurements of albuminuria and estimated glomerular filtration rate (eGFR); defining treatment outcomes; glycemic management in both those developing CKD and those with ESRD; hypertension goals and management, including blockers of the renin-angiotensin-aldosterone system; and lipid management.

Follow-up of secondary diabetic complications after pancreas transplantation

PURPOSE OF REVIEW

Successful pancreas transplantation restores physiologic glycemic and metabolic control. Its effects on overall patient survival (especially for simultaneous pancreas-kidney transplantation) are clear-cut. We herein review the available literature to define the impact of pancreas transplantation on chronic complications of diabetes mellitus.

RECENT FINDINGS

With longer-term follow-up, wider patient populations, and more accurate investigational tools (clinical and functional tests, noninvasive imaging, histology, and molecular biology), growing data show that successful pancreas transplantation may slow the progression, stabilize, and even favor the regression of secondary complications of diabetes, both microvascular and macrovascular, in a relevant proportion of recipients.

SUMMARY

Patients who are referred for pancreas transplantation usually suffer from advanced chronic complications of diabetes, which have classically been deemed irreversible. A successful pancreas transplantation is often able to slow the progression, stabilize, and even reverse many microvascular and macrovascular complications of diabetes. Growing clinical evidence shows that the expected natural history of long-term diabetic complications can be significantly modified by successful pancreas transplantation.

Pancreas transplant as treatment to arrest renal function decline in patients with type 1 diabetes and proteinuria

Recent findings from the Diabetes Control and Complications Trial and Epidemiology of Diabetes Interventions and Complications study showed that long-term improved glycemic control in patients with type 1 diabetes with normal renal function and normoalbuminuria can delay development of impaired renal function by at least 6.5 years, although the reduction in the relative risk of end-stage renal disease (ESRD) was not significant. The unanswered question is: can improvement of glycemic control delay the onset of ESRD in patients with established diabetic nephropathy? In this context, pancreas transplantation (PATx) can be considered the most effective intervention to restore normoglycemia. Can this aggressive/experimental intervention be applied to arrest/retard renal function decline? To answer this question, this review summarizes the relevant findings from observational studies conducted in cohorts of patients, followed up for 4 to 15 years, who underwent PATx. These noncontrolled studies provided positive answers to the earlier question, principally concerning a significant decrease in albumin excretion levels. However, current drugs used to prevent rejection could impair renal function, principally in recipients with low pretransplant estimated glomerular filtration rate (ie, <60 mL/min). Unfortunately, all these studies had shortcuts that qualify interpretation of the findings. First, it is unclear how much initial estimated glomerular filtration rate loss results from nephrotoxic effect of antirejection drugs, and how much results from improved glycemia and its impact on the reduction of hyperfiltration. Second, the study designs did not consider the wide variation in rates of renal function loss observed in patients with established nephropathy (ie, one third are nonprogressors, one third are slow progressors, and one third are rapid progressors). Third, all studies were observational in nature and clinical trials are needed to properly evaluate the effectiveness of normalization of hyperglycemia through PATx on postponing the onset of ESRD in type 1 diabetes.

Surgical strategies for type II diabetes

Diabetes mellitus type II (or type 2 diabetes; DM2) has multiple definitions but is generally considered to be a disease marked by insulin resistance and loss of β cell function that develops in adulthood. Today, greater than 90% of patients with diabetes have DM2. When uncontrolled, DM2 may result in comorbidities such as cardiovascular disease, retinopathy, neuropathy, immune system dysfunction, and renal failure. Classically, treatment of type 2 diabetes has included dietary and lifestyle changes. Even with behavior modification and oral hypoglycemics, many patients are unable to maintain glycemic control. With a growing understanding of the hormonal signals involved in the pathogenesis of type 2 diabetes, there has been a shift in the therapeutic approach to this growing epidemic. Bariatric surgery has been shown to decrease the progression and potentially reverse the effects of diabetes in 80% to 90% of patients. In addition, bariatric operations are associated with sustained weight loss in contrast to nonsurgical options. The antidiabetic effect of bariatric operations is likely due to the improvement in the hormonal dysregulation associated with the development of diabetes. Many patients with diabetes, however, have irreparably damaged insulin production capabilities as well. In addition, it is well recognized that transplantation may be required for patients with severe loss of islet cell function. Surgery for type 2 diabetes, via bariatric procedures and transplantation, has become an important treatment modality for patients with advanced disease.

Renal function in type 1 diabetics one year after successful pancreas transplantation

The effect of pancreas transplantation on renal function remains a matter of debate. The purpose of this retrospective, single-unit study is a preliminary analysis of renal function one yr after pancreas transplant (pancreas alone [PTA] or pancreas after kidney [PAK]). Fifty-nine patients were included. Serum creatinine and estimated glomerular filtration rate (eGFR) levels were compared three, six, and 12 months post-transplantation for the whole sample and separately for PTA and PAK and high (>45 mL/min/1.73 m(2)) and low (≤45 mL/min/1.73 m(2)) pre-transplant eGFR subgroups. Overall, eGFR did not change significantly (p = 0.228) at the end of the first year post-transplant, with patients of low initial eGFR presenting a more prominent trend toward stable or improved levels. In the PAK subgroup, eGFR was significantly improved (p = 0.035). High eGFR subgroup demonstrated no significant deterioration in renal function, while patients with low initial eGFR had significantly higher levels 3 (p = 0.012) and six months (p = 0.009) post-transplant. Our study shows that renal function did not deteriorate significantly one yr after pancreas transplant (PTA or PAK), even in patients with substantial pre-existing renal dysfunction. Evaluation at a wider scale and identification of risk factors for potential deterioration are challenges for future research.

Risk analysis for deterioration of renal function after pancreas alone transplant

The risk of progression to renal replacement after pancreas transplant alone (PTA) is a concern in patients with pre-transplant estimated glomerular filtration rate (eGFR) < 70 mL/min/1.73 m(2). This is a retrospective, single-center risk analysis of potential factors affecting renal function after PTA. Twenty-four patients, transplanted over a three-yr period, with functioning pancreatic grafts at the study's end point were included. High tacrolimus levels (> 12 mg/dL) at six months post-transplant was the only independent risk factor identifying a substantial decline in native renal function by Cox regression analysis (HR = 14.300, CI = 1.271-160.907, p = 0.031). The presence of severe pre-transplant proteinuria (urine Pr/Cr ≥ 100 mg/mmol) marginally failed to reach significance (p = 0.056). Low eGFR levels alone (≤ 45 and ≤ 40 mL/min/1.73 m(2)) at the time of transplant did not correlate with substantial decline in renal function. Our data suggest that PTA is a justifiable therapy for patients with hypoglycemia unawareness or other life-threatening diabetic complications, even in those with borderline renal function, provided that they do not suffer from severe proteinuria and appropriate monitoring and tailoring of immunosuppression is ensured.

Results of pancreas transplantation alone with special attention to native kidney function and proteinuria in type 1 diabetes patients

We report on our single-center experience with pancreas transplantation alone (PTA) in 71 patients with type 1 diabetes, and a 4-year follow-up. Portal insulin delivery was used in 73.2% of cases and enteric drainage of exocrine secretion in 100%. Immunosuppression consisted of basiliximab (76%), or thymoglobulin (24%), followed by mycophenolate mofetil, tacrolimus, and low-dose steroids. Actuarial patient and pancreas survival at 4 years were 98.4% and 76.7%, respectively. Relaparatomy was needed in 18.3% of patients. Restored endogenous insulin secretion resulted in sustained normalization of fasting plasma glucose levels and HbA1c concentration in all technically successful transplantations. Protenuria (24-hour) improved significantly after PTA. Renal function declined only in recipients with pretransplant glomerular filtration rate (GFR) greater than 90 ml/min, possibly as a result of correction of hyperfiltration following normalization of glucose metabolism. Further improvements were recorded in several cardiovascular risk factors, retinopathy, and neuropathy. We conclude that PTA was an effective and reasonably safe procedure in this single-center experience.

Current status of pancreas transplantation

Pancreas transplantation has emerged as the treatment of choice for patients with end-stage diabetes mellitus. Over the last four decades, many improvements have been made in the surgical techniques and immunosuppressive regimens, which contributed to increased number of indications and improved allograft survival. Pancreas transplantation can be justified on the basis that patients replace daily injections of insulin with an improved quality of life but at the expense of a major surgical procedure with a relatively higher complication rate, and lifelong immunosuppression. Therefore, efforts to develop more minimally invasive techniques for endocrine replacement therapy such as islet transplantation have been in progress. This article summarizes the current understanding of pancreas transplantation-associated indications, donor selection, surgical techniques, immunosuppression, and rejection.

Pancreas transplantation

Since the introduction of pancreas transplantation more than 40 years ago, efforts to develop more minimally invasive techniques for endocrine replacement therapy have been in progress, yet this surgical procedure still remains the treatment of choice for diabetic patients with end-stage renal failure. Many improvements have been made in the surgical techniques and immunosuppressive regimens, both of which have contributed to an increasing number of indications for pancreas transplantation. This operation can be justified on the basis that patients replace daily injections of insulin with an improved quality of life but at the expense of a major surgical procedure and lifelong immunosuppression. The various indications, categories, and outcomes of patients having a pancreas transplant are discussed, particularly with reference to the effect on long-term diabetic complications.