Effects of pancreas-kidney transplantation on diabetic retinopathy

Intravenous injection of cyclosporin A loaded lipid nanocapsules fights inflammation and immune system activation in a mouse model of diabetic retinopathy

Inflammation and immune system activation are key pathologic events in the onset and escalation of diabetic retinopathy (DR). Both are driven by cytokines and complement originating from the retinal pigment epithelium (RPE). Despite the RPE's pivotal role, there is no therapeutic tool to specifically interfere with the RPE-related pathomechanism. A therapy that addresses RPE cells and counteracts inflammation and immune response would be of paramount value for the early treatment of DR, where currently are no specific therapies available. Here, we utilized lipoprotein-mimetic lipid nanocapsules to deliver the anti-inflammatory and immunosuppressive drug cyclosporin A (CsA) to RPE cells. Using a mouse model of DR that mirrors all pathologic aspects of human DR, we demonstrate that intravenously applied CsA-loaded lipid nanocapsules comprehensively counteract inflammation and immune system activation. One single injection suppressed the expression of pro-inflammatory cytokines, dampened macrophage infiltration, and prevented macrophage and microglia activation in eyes with DR. This work shows that CsA-loaded lipid nanocapsules can offer new avenues for the treatment of DR.

Jejunal or Ileal Exocrine Drainage in Pancreas Transplantation: Impact on Gastrointestinal Function

OBJECTIVES

Pancreas transplant can have serious complications requiring salvage pancreatectomy, and surgical approaches should be carefully considered, with jejunal or ileal anastomoses most often employed. The jejunum may reduce gastrointestinal disturbance, whereas the ileum is more immunogenic. Proximal gastrointestinal anastomoses pose challenges with salvage pancreatectomy and creation of high-output stoma, often in the context of end-stage renal failure. Here, we compared outcomes between these techniques.

MATERIALS AND METHODS

We retrospectively analyzed patient records of simultaneous pancreas and kidney transplants at a single center between 2013 and 2015, with follow-up to 2020.

RESULTS

Our center performed 86 simultaneous pancreas and kidney transplants during the study period; 10 patients were excluded because of incomplete records of anastomosis type. Of included recipients, 59.2% were men (mean age 41.5 ± 8.4 y), 72.4% were donors after brain death, and 98.7% had received a first pancreas transplant. Forty-three simultaneous pancreas and kidney transplants were performed with ileal anastomosis and 33 with jejunal anastomosis. We found no significant differences in recipient or donor factors or immunosuppression regimen between anastomosis groups and no significant differences in overall patient, pancreas, or kidney graft survival or in gastrointestinal complications. Hospital length of stay was higher with ileal anastomosis (median 14 vs 19 days; P < .05), as was cold ischemic time (median 8:48 vs 9:31 hours; P < .05). Three patients required salvage pancre-atectomy and loop ileostomy formation with multiorgan support, prolonged intensive care unit stay, relaparotomy, and/or laparostomy.

CONCLUSIONS

Long-term outcomes were comparable between our patient groups. Catastrophic complica-tions occur in a minority of cases, requiring salvage surgery. More complications occurred with ileal anastomosis, but this approach allows graft pancreatectomy and formation of loop ileostomy, avoiding a more proximal stoma in clinically unstable patients. Further studies are needed to examine the impact of enteric anastomosis site.

Hemoperfusion and functional state of the macula after simultaneous pancreas and kidney transplantation

Simultaneous pancreas and kidney transplantation (SPK) provides effective treatment in patients with type 1 diabetes mellitus (T1DM) and end-stage renal failure (ESRF), mitigating the hyperglycemia and uremic syndrome. The study aimed at the assessment of morphofunctional status of the macula and macular hemodynamics in patients with T1DM after SPK. The study enrolled 45 patients subdivided into three groups: Group A — patients with T1DM after SPK; Group B — patients with T1DM and ESRF, maintained on programmed hemodialysis (PH), on waiting list for SPK; and Group C — individuals without ophthalmic or systemic pathologies. All patients were subject to the standard ophthalmological examination complemented by measurements of the central retinal thickness (CRT) and the average perfusion density (PD) in four vascular layers: superficial capillary plexus of the retina (SCP), deep capillary plexus of the retina (DCP), choriocapillaris, and choroid. The patients after SPK had significantly lower CRT (241 ± 33 µm in Group A, 309±10 µm in Group B; p < 0.05) and significantly higher PD of the macular region in both the retina (Group A: SCP — 19.0 ± 1.6%, DCP — 10.7 ± 1.3%; Group B: SCP — 11.7 ± 0.8%, DCP — 4.8 ± 0.8%; p < 0.05) and the choroid (Group A: choriocapillaris — 28.1 ± 1.8%, choroid — 31.3 ± 1.6%; Group B: choriocapillaris — 20.4 ± 1.6%, choroid — 21.8 ± 1.3%; p < 0.05), as well as significantly higher visual acuity (Group A: 0.7 ± 0.1; Group B: 0.5 ± 0.1; p < 0.05) and macular light threshold (Group A: 25.9 ± 1.4 dB; Group B: 22.3 ± 1.1 dB; p < 0.05) compared with the patients on PH. Thus, the normalization of carbohydrate metabolism and the mitigation of uremic syndrome in patients with T1DM and ESRF after SPK favorably affect the functional condition of the macular area, as indicated by the improvement in macular blood flow and visual functions.

First World Consensus Conference on pancreas transplantation: Part II - recommendations

The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Factors affecting diabetic patient's long-term quality of life after simultaneous pancreas-kidney transplantation: a single-center analysis

PURPOSE

Pancreas transplantation (PT) is one of the few ways to restore euglycemia within diabetic patients; however, the high morbidity caused by surgical complications and the need for immunosuppressive therapy has raised controversy about PT improving the health-related quality-of-life (HRQoL). The aim of this study is to assess the long-term (≥ 5 years after PT) HRQoL and to identify the factors affecting it.

METHODS

A single-center, cross-sectional study of 49 sequential PT was performed. All patients conducted a telephone interview to fulfill the modification of Medical Outcome Health Survey Short Form questionnaire (SF-36v2) and were compared to similar post-PT studies from the literature.

RESULTS

Patients with a history of replacement renal therapy (RRT) or neuropathy undergoing a PT were associated to a worse bodily pain (P = 0.03) and physical function (P = 0.04), respectively, whereas those with retinopathy showed an improved Role Emotional (P = 0.04). Multivariate analysis revealed the presence of RRT as the only independent prognostic factor for a worse bodily pain [relative risk = 3.9; 95% confidence interval (1.1-14.6)], (P = 0.04). Furthermore, nearly all PT recipients (91.8%) claimed an overall better health than prior to PT.

CONCLUSION

Our study confirms that PT recipients' HRQoL improves after PT, showing similar HRQoL scores across different populations and suggests that patients in predialysis could benefit from an improved HRQoL if transplanted on the early stages of the disease.

Early worsening of diabetic retinopathy after simultaneous pancreas and kidney transplantation-Myth or reality?

Early worsening of diabetic retinopathy due to sudden glucose normalization is a feared complication of pancreas transplantation; however, its rate or severity has not been studied prospectively. We followed up 43 pancreas and kidney recipients for a composite endpoint comprising new need for laser therapy, newly diagnosed proliferation, macular edema, visual acuity worsening, and blindness over 12 months. Although 37% of patients met this primary endpoint, its severity was rather low. Mean central retinal thickness and proportion of patients with subclinical macular edema increased significantly, with spontaneous resolution in half of them. Visual acuity did not change. There was no significant difference in the absolute glycated hemoglobin (HbA1c) drop, age, and diabetes duration between the patients who met and those who did not meet the primary endpoint, but a higher proportion of patients with worsening had a recent history of laser treatment. Retinopathy remained stable in 62.8% of patients. In 26%, the visual acuity significantly improved. Although retinopathy worsening was documented in more than one-third of patients, its evolution was not related to the magnitude of metabolic change; rather, it corresponded to the expected natural course of retinopathy. Nonetheless, comprehensive ophthalmologic care should be a substantial component of the recipient management.

Retrospective Analysis of Bone Metabolism in Patients on Waiting List for Simultaneous Pancreas-Kidney Transplantation

Posttransplant osteoporosis, which evolves from preexisting bone pathologies, represents a serious complication with deteriorating consequences. The aim of our study was to evaluate epidemiological data on bone mineral density (BMD) in subjects with type 1 diabetes (T1DM) in advanced stages of diabetic nephropathy indicated for simultaneous pancreas-kidney transplantation (SPK). We retrospectively compiled biochemical and densitometrical data from 177 patients with T1DM at CKD (chronic kidney disease) stages G4-G5 (115 men, 62 women, median age 40 yr, diabetes duration 23 yr) enrolled on waiting list for SPK for the first time between the years 2011 and 2016. Median Z-scores were as follows: lumbar spine (LS): -0.8 [interquartile range -1.75 to 0.1]; total hip (TH): -1.2 [-1.75 to -0.6]; femoral neck (FN): -1.2 [-1.9 to -0.7]; and distal radius (DR): -0.8 [-1.4 to -0.1]. We noted a gender difference in LS, with worse results for men (-1.1 vs. -0.3) even after adjusting for BMI (body mass index) and glomerular filtration (p < 0.001). Osteoporotic and osteopenic ranges (based on T-scores) for all major sites were 27.7% and 56.5%, respectively, with similar results across both genders. Women had a significantly higher proportion of normal BMD in LS than men (67.7 vs. 49.4%, p < 0.05). Patients with T1DM at CKD stages G4-G5 exhibited serious BMD impairment despite their young age. Men surprisingly displayed lower Z-scores and higher percentages of pathological BMD values in LS than women did. The introduction of adequate preventive measures during the advanced stages of diabetic nephropathy to prevent bone loss is recommended.

Long-term Effects of Pancreas Transplantation on Diabetic Retinopathy and Incidence and Predictive Risk Factors for Early Worsening

BACKGROUND

Limited data are available regarding the long-term effects of pancreas transplantation on the progression of diabetic retinopathy (DR) and the incidence and associated risk factors for early worsening of DR.

METHODS

Patients who underwent successful pancreas transplantation between January 2007 and October 2015 and were followed for 1 year or longer were consecutively enrolled. Variables regarding demographic, systemic, metabolic, and surgical factors were reviewed for each patient. DR progression was defined as (i) development or aggravation of macular edema requiring intravitreal anti-VEGF injections and/or (ii) progression of DR severity requiring panretinal photocoagulation (PRP) and/or pars planar vitrectomy (PPV). Early worsening was defined as progression within 1 year of posttransplant.

RESULTS

Three hundred three eyes of 153 patients were included in the analysis. At the pretransplant ocular evaluation, 221 eyes (72.9%) showed advanced DR with history of PRP and/or PPV. During a mean follow-up period of 4.2 years, 62 eyes (20.5%) experienced DR progression, and early worsening was noted in 57 eyes (18.8%). DR with recent PRP within pretransplant 1 year and pancreas transplant alone were significant risk factors for early worsening.

CONCLUSIONS

In 4 of 5 patients who received pancreas transplant, the degree of DR remained stable over time after transplantation. Meanwhile, early worsening of DR could occur in patients at risk, particularly within the first posttransplant year. We suggest that physicians should have a high index of suspicion and carefully monitor for early worsening of DR and timely manage possible ocular deterioration.

Long-term diabetes complications after pancreas transplantation

PURPOSE OF REVIEW

The intention of this study is to summarize present knowledge about adverse effects of hyperglycemia in diabetes, and in this context review more recent data concerning the effects of pancreas transplantation on a wide range of diabetic complications.

RECENT FINDINGS

Effective blood glucose control by insulin delays progression of microvascular complications and probably improves survival in type 1 diabetes. A successful pancreas transplantation combined with a kidney graft has recently been found to prevent diabetic kidney lesions, and registry data support improved long-term patient survival. Cardiovascular mortality was reduced in one study, even though coronary heart disease was not significantly altered. Advanced coronary lesions may be too advanced in these patients at baseline. However, with a successful single pancreas transplant, which is generally performed in patients with near-normal kidney function, pancreas transplantation may improve left ventricular function. Development of retinopathy and neuropathy is delayed with functioning pancreas grafts, and both quality of life and certain skin lesions may improve after pancreas transplantation.

SUMMARY

In patients with type 1 diabetes, pancreas transplantation may improve cardiac outcomes and ameliorate diabetic lesions in the kidney transplant. Also quality of life, neuropathy, retinopathy, and healing of certain skin lesions may be improved.

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.

Retinal changes in solid organ and bone marrow transplantation patients

Objective

To evaluate retinal changes in patients who underwent solid organ or bone marrow transplantation.

Methods

A retrospective analysis of medical records of patients evaluated from February 2009 to December 2016. All patients included underwent funduscopy. Clinical and demographic data regarding transplantation and ophthalmological changes were collected.

Results

A total of 126 patients were analyzed; of these, 108 underwent transplantation and 18 were in the waiting list. Transplantation modalities were heart, lung, kidney, liver, pancreas, combined pancreas and kidney and bone marrow transplantation. The main pre-transplantation comorbidities were diabetes and arterial hypertension. Of the 108 transplanted patients, 82 (76%) had retinal changes. All patients who underwent pancreas or combined pancreas and kidney transplantation had diabetic retinopathy. The main retinal changes found were diabetic retinopathy, hypertensive retinopathy, retinal vascular occlusions, chorioretinal infections and central serous chorioretinopathy.

Conclusion

Retinal changes were either related to preexisting conditions, mainly diabetic retinopathy, or developed postoperatively as a complication of the surgical procedure, or as an infection related to the immunosuppressive status, or due to drug toxicity. These patients may present with complex ophthalmological changes and should be carefully evaluated prior to surgery and further followed by an ophthalmologist skilled in the management of diabetic retinopathy and posterior pole infections.

Interventions for Diabetic Retinopathy in Type 1 Diabetes: Systematic Review and Meta-Analysis

PURPOSE

To systematically review the effectiveness of systemic interventions for diabetic retinopathy (DR) in type 1 diabetes.

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE and Cochrane Library were searched for studies published from January 1990 to December 2014. Randomized controlled trials and controlled cohort studies reporting incidence or progression of DR following systemic intervention were included. Two reviewers selected studies, extracted data, and assessed risk of bias. For each intervention, pooled outcomes were reported as relative risk (RR) estimates with 95% confidence intervals (CI).

RESULTS

Twenty-four studies involving 9302 patients met inclusion criteria. Incident DR was reduced by intensive vs conventional insulin therapy (RR 0.43; 95% CI 0.23-0.83), insulin pumps vs multiple daily injections (RR 0.45; 95% CI 0.24-0.83), and angiotensin receptor blockade vs placebo (RR 0.65; 95% CI 0.49-0.85). The benefit of insulin pumps over multiple daily infections was independent of HbA1c. DR progression was reduced by intensive vs conventional insulin therapy (RR 0.63; 95% CI 0.43-0.92), angiotensin-converting enzyme inhibition vs placebo (RR 0.60; 95% CI 0.41-0.86), and islet cell transplantation vs medical therapy (RR 0.25; 95% CI 0.08-0.71).

CONCLUSIONS

Intensive insulin therapy, and specifically insulin pump therapy vs multiple daily injections, prevents DR in both adults and adolescents with type 1 diabetes. Antihypertensive agents provide protection in normotensive, normoalbuminuric adults. In patients with type 1 diabetes of longer duration, islet cell transplantation may be more effective than medical therapy. There is insufficient evidence for antilipid therapy or other systemic interventions.

Successful Combined Pancreas Fourth-Kidney Third and Pancreas Third-Kidney Second Transplantation: A Case Report

Extremely few reports have been published on experience with multiple combined pancreas-kidney re-transplantation including long-term results. We here analyze our experience with two patients following successful combined pancreas fourth-kidney third and pancreas third-kidney second transplantation.

METHODS

Patient and graft survival as well as graft function and major complications were recorded. Patient 1 (women, 47 years) underwent combined pancreas fourth-kidney third transplantation after previous removal of the first and second renal and the second pancreatic grafts. Patient 2 (men, 51 years) underwent combined pancreas third-kidney second transplantation after nephrectomy of the first renal graft. Immunosuppression consisted of induction with alemtuzumab and maintenance with tacrolimus, mycophenolate mofetil/mycophenolic acid and steroids.

RESULTS

After a follow-up of 44 and 49 months, respectively, both patients are doing well with stable graft function. Leukopenia, thrombocytopenia, bacterial sepsis, and chronic hepatitis C as major complications were controllable.

CONCLUSIONS

Multiple pancreas-retransplantations combined with simultaneous renal transplantation are feasible. Meticulous immunosuppression, careful monitoring, and excellent patient adherence are of crucial importance.

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.

Extended pancreas donor program - the EXPAND study rationale and study protocol

BACKGROUND

Simultaneous pancreas kidney transplantation (SPK), pancreas transplantation alone (PTA) or pancreas transplantation after kidney (PAK) are the only curative treatment options for patients with type 1 (juvenile) diabetes mellitus with or without impaired renal function. Unfortunately, transplant waiting lists for this indication are increasing because the current organ acceptability criteria are restrictive; morbidity and mortality significantly increase with time on the waitlist. Currently, only pancreas organs from donors younger than 50 years of age and with a body mass index (BMI) less than 30 are allocated for transplantation in the Eurotransplant (ET) area. To address this issue we designed a study to increase the available donor pool for these patients.

METHODS/DESIGN

This study is a prospective, multicenter (20 German centers), single blinded, non-randomized, two armed trial comparing outcome after SPK, PTA or PAK between organs with the currently allowed donor criteria versus selected organs from donors with extended criteria. Extended donor criteria are defined as organs procured from donors with a BMI of 30 to 34 or a donor age between 50 and 60 years. Immunosuppression is generally standardized using induction therapy with Myfortic, tacrolimus and low dose steroids. In principle, all patients on the waitlist for primary SPK, PTA or PAK are eligible for the clinical trial when they consent to possibly receiving an extended donor criteria organ. Patients receiving an organ meeting the current standard criteria for pancreas allocation (control arm) are compared to those receiving extended criteria organ (study arm); patients are blinded for a follow-up period of one year. The combined primary endpoint is survival of the pancreas allograft and pancreas allograft function after three months, as an early relevant outcome parameter for pancreas transplantation.

DISCUSSION

The EXPAND Study has been initiated to investigate the hypothesis that locally allocated extended criteria organs can be transplanted with similar results compared to the currently allowed standard ET organ allocation. If our study shows a favorable comparison to standard organ allocation criteria, the morbidity and mortality for patients waiting for transplantation could be reduced in the future.

TRIAL REGISTRATION

Trial registered at: NCT01384006.

[Role of simultaneous pancreas-kidney transplantation in the treatment of diabetes mellitus]

The life expectancy of patients with type 1 diabetes mellitus is inferior to that of patients with some malignancies. Simultaneous pancreas-kidney transplantation is the procedure providing the best survival results among all options of renal replacement therapy. The operative techniques and immunosuppresion have been standardized in the last decade. Although the number of transplantable organs falls behind the need, simultaneous pancreas-kidney transplantation is the method of choice for the eligible patients. The results of the two Hungarian simultaneous pancreas-kidney transplantation programs are in accordance with data published in the international literature.

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.

Corneal confocal microscopy detects early nerve regeneration in diabetic neuropathy after simultaneous pancreas and kidney transplantation

Diabetic neuropathy is associated with increased morbidity and mortality. To date, limited data in subjects with impaired glucose tolerance and diabetes demonstrate nerve fiber repair after intervention. This may reflect a lack of efficacy of the interventions but may also reflect difficulty of the tests currently deployed to adequately assess nerve fiber repair, particularly in short-term studies. Corneal confocal microscopy (CCM) represents a novel noninvasive means to quantify nerve fiber damage and repair. Fifteen type 1 diabetic patients undergoing simultaneous pancreas-kidney transplantation (SPK) underwent detailed assessment of neurologic deficits, quantitative sensory testing (QST), electrophysiology, skin biopsy, corneal sensitivity, and CCM at baseline and at 6 and 12 months after successful SPK. At baseline, diabetic patients had a significant neuropathy compared with control subjects. After successful SPK there was no significant change in neurologic impairment, neurophysiology, QST, corneal sensitivity, and intraepidermal nerve fiber density (IENFD). However, CCM demonstrated significant improvements in corneal nerve fiber density, branch density, and length at 12 months. Normalization of glycemia after SPK shows no significant improvement in neuropathy assessed by the neurologic deficits, QST, electrophysiology, and IENFD. However, CCM shows a significant improvement in nerve morphology, providing a novel noninvasive means to establish early nerve repair that is missed by currently advocated assessment techniques.

A Modified Perfusion Method to Improve the Quality of Procured Donor Pancreas in Rats

Background

In this animal study, we evaluated a modified pancreas perfusion method to improve the quality of harvested pancreas in rats. In this model, the portal vein was used as the outflow route during the pancreas perfusion.

Methods

Forty-eight male Wistar rats were randomly divided into study group and control group, with 24 rats in each group. In the study group, the portal vein was used as outflow of perfusion. While in the control group, the post-hepatic vein (right artrium) was used as perfusion outflow. UW solution was used as perfusion and preservation solution. Pancreas tissue samples were collected at 6, 10, and 14 hours after perfusion and cold preserved for histology and immunohistochemistry examination, P-selection (PS) and ICAM-1 were determined. Pancreas samples were also examined using electronic microscope for ultra-structures.

Results

Compared with the study group, in the pancreas of control group there were significant pathological impairments and cellular ultra-structural alterations observed by immunohistochemistry and electronic microscope, and these impairments aggravated with time. There were mild histological alterations in the pancreas of study group.

Conclusions

During the donor pancreas perfusion, the early opening of portal vein as the outflow is better than the opening of the post-hepatic vein for the preservation of donor graft pancreas and the reduction of tissue impairments.

Transplantation of the pancreas

Pancreas transplantation consistently induces insulin-independence in beta-cell-penic diabetic patients, but at the cost of major surgery and life-long immunosuppression. One year after grafting, patient survival rate now exceeds 95 % across recipient categories, while insulin independence is maintained in some 85 % of simultaneous pancreas and kidney recipients and in nearly 80 % of solitary pancreas transplant recipients. The half-life of the pancreas graft currently averages 16.7 years, being the longest among extrarenal grafts, and substantially matching the one of renal grafts from deceased donors. The difference between expected (100 %) and actual insulin-independence rate is mostly explained by technical failure in the postoperative phase, and rejection in the long-term period. Death with a functioning graft remains a further major issue, especially in uremic patients who have undergone prolonged periods of dialysis. Refinements in graft preservation, surgical techniques, immunosuppression, and prophylactic treatments are expected to further improve the results of pancreas transplantation.

Curing diabetes with transplantation?

Type 1 diabetes affects >1 million people in the United States, where it accounts for up to 10% of all diabetes cases. Glycemic control via the use of exogenous insulin injections in diabetic patients is incomplete, resulting in multiple long-term complications such as retinopathy, neuropathy, vasculopathy, and nephropathy. The goal of beta-cell replacement by whole-pancreas or islet transplantation is to achieve long-term insulin independence, and the proposed benefits are improved quality of life, prevention of recurrent diabetic nephropathy, stabilization or improvement in secondary complications, and improved mortality. No other regimen of insulin delivery can achieve this level of physiologic regulation.

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.

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

BACKGROUND

Pancreas and islet transplantation are the only available options to replace beta-cell function in patients with type 1 diabetes. Great variability in terms of rate of success for both approaches is reported in the literature and it is difficult to compare the respective risks and benefits.

OBJECTIVES

The aim of this study was to analyze risks and benefits of pancreas transplantation alone (PTA) and islet transplantation alone (ITA) by making use of the long-term experience of a single center where both transplantations are performed. We focused on the risks and benefits of both procedures, with the objective of better defining indications and providing evidence to support the decision-making process. The outcomes of 33 PTA and 33 ITA were analyzed, and pancreas and islet function (i.e., insulin independence), perioperative events, and long-term adverse events were recorded.

RESULTS

We observed a higher rate of insulin independence in PTA (75%) versus ITA (59%), with the longer insulin independence among PTA patients receiving tacrolimus. The occurrence of adverse events was higher for PTA patients in terms of hospitalization length and frequency, re-intervention for surgical and immunological acute complications, CMV reactivation, and other infections.

CONCLUSIONS

In conclusion, these results support the practice of listing patients for PTA when the metabolic control and the progression of chronic complications require a rapid normalization of glucose levels, with the exception of patients with cardiovascular disease, because of the high surgical risks. ITA is indicated when replacement of beta-cell mass is needed in patients with a high surgical risk.

Reduced progression of diabetic microvascular complications with islet cell transplantation compared with intensive medical therapy

BACKGROUND

The effect of islet cell transplantation (ICT) on the progression of diabetic microvascular complications is not well understood.

METHODS

We have conducted a prospective, crossover, cohort study comparing ICT with intensive medical therapy on the progression of diabetic nephropathy, retinopathy, and neuropathy.

RESULTS

The rate of decline in glomerular filtration rate is slower after ICT than on medical therapy. There was significantly more progression of retinopathy in medically treated patients than post-ICT. There was a nonsignificant trend for improved nerve conduction velocity post-ICT.

CONCLUSIONS

ICT is associated with less progression of microvascular complications than intensive medical therapy. Multicenter, randomized trials are needed to further study the role of ICT in slowing the progression of diabetic complications.

Evolution of β-Cell Replacement Therapy in Diabetes Mellitus: Pancreas Transplantation

Diabetes mellitus remains one of the leading causes of morbidity and mortality worldwide. According to the Centers for Disease Control and Prevention, approximately 23.6 million people in the United States are affected. Of these individuals, 5-10% have been diagnosed with type 1 diabetes mellitus (TIDM), an autoimmune disease. Although it often appears in childhood, T1DM may manifest at any age. The effects of T1DM can be devastating, as the disease often leads to significant secondary complications, morbidity, and decreased quality of life. Since the late 1960s, surgical treatment for diabetes mellitus has continued to evolve and has become a viable alternative to chronic insulin administration. In this review, the historical evolution, current status, graft efficacy, benefits, and complications of pancreas transplantation are explored.

Islet versus pancreas transplantation in type 1 diabetes: competitive or complementary?

Whole organ pancreas and pancreatic islet transplantation are currently the only forms of clinically available β-cell replacement. Both therapeutic options can provide good glycemic control and prevention or stabilization of diabetic complications, but at the price of permanent immunosuppression. Therefore, the indication for transplantation of type 1 diabetes patients must be balanced carefully and should be restricted to a subgroup of patients with extreme lability of metabolic control and frequent hypoglycemia despite optimal medical therapy.

Impact of pancreas transplantation on type 1 diabetes-related complications

PURPOSE OF REVIEW

Type 1 diabetes is a chronic disease that can impact patient survival and quality of life because of acute and chronic complications. Although intensive insulin scheme treatment has been shown to reduce the incidence of diabetes-related complications, only pancreas transplantation has been shown to be able to alter them and in some cases to revert them. In this review, an extensive view of the effect of pancreas transplantation on diabetes-related complication will be described.

RECENT FINDINGS

This review will focus on patients survival, diabetic nephropathy, neuropathy, cardiovascular event, comparing their incidence in type 1 diabetic patients treated with insulin and in type 1 diabetic patients receiving kidney, kidney-pancreas or pancreas alone graft. The review will focus mostly on the papers published in the last decade, with a particular attention to those on new aspects of graft function analysis like spectroscopy. Moreover, a comparison with islet transplantation procedure will be performed.

SUMMARY

This review will give an update on the potential of pancreas transplantation, give a guide for clinical practice and help to consider pancreas transplantation as an alternative to insulin treatment for selected patients.

Simultaneous pancreas kidney transplantation: a critical appraisal of the risks and benefits compared with other treatment alternatives

Advances in technical aspects of pancreas transplantation and improvements in immunosuppression over the last decade have led to significant improvements in pancreas transplant outcomes in the short-term. Simultaneous kidney pancreas transplantation remains an attractive option for patients with type 1 diabetes (T1DM) and late chronic kidney disease (CKD), with 1-year pancreas graft survival rates of 86% in 2004. For the individual patient with T1DM and CKD, the various transplant options must be considered carefully, with attention to the timing of surgery relative to the need for dialysis, the challenge in managing diabetes with noninvasive medical therapy, and the assumption of risks attendant to each surgical option. This review summarizes the current status of simultaneous pancreas kidney transplantation and compares and contrasts outcomes with other potential treatment options.

A multi-year analysis of islet transplantation compared with intensive medical therapy on progression of complications in type 1 diabetes

BACKGROUND

We hypothesized that transplantation of islets into type 1 diabetics could improve outcomes of glucose metabolism, renal function, retinopathy, and neuropathy compared with intensive medical therapy.

METHODS

We conducted a prospective, crossover, cohort study of intensive medical therapy (group 1) versus islet cell transplantation (group 2) in 42 patients. All were enrolled in group 1 then 31 crossed over with group 2 when islet donation became available. Transplantation was performed by portal venous embolization of more than 12,000 islet equivalents/kg body weight under cover of immunosuppression with antithymocyte globulin, tacrolimus, and mycophenolate. Outcome measures were HbA1c, change in glomerular filtration rate (GFR), progression of retinopathy, and change in nerve conduction velocity. This report details interim analysis of outcomes after 34+/-18 months (group 1) and 38+/-18 months (group 2).

RESULTS

HbA1c (%) in group 1 was 7.5+/-0.9 versus 6.6+/-0.7 in group 2 (P<0.01). GFR (mL/min/month) declined in both groups (group 1 -0.45+/-0.7 vs. group 2 -0.12+/-0.7, P=0.1). Slope of the GFR decline in group 1 was significantly more than 0. Retinopathy progressed in 10 of 82 eyes in group 1 versus 0 of 51 in group 2 (P<0.01). Nerve conduction velocity (m/sec) remained stable in group 1 (47.8+/-5 to 47.1+/-5 m/sec) and group 2 (47.2+/-4.5 to 47.7+/-3.5).

CONCLUSION

Islet transplantation yields improved HbA1c and less progression of retinopathy compared with intensive medical therapy during 3 years follow-up.

Management of painful diabetic neuropathy

The commonest cause of peripheral neuropathy is diabetes and pain occurs in approximately 30% of diabetic patients with neuropathy. It is extremely distressing for the patient and poses significant difficulties in management, as no treatment to date provides total relief and the side effects of therapy limit dose titration. Understanding the pathogenesis of diabetic neuropathy may lead to the development of new treatments for preventing nerve damage. Furthermore, a better understanding of the mechanisms that modulate pain may lead to more effective relief of painful symptoms. This review provides an update on the assessment and treatment of painful diabetic neuropathy.

Temporal relationship between successful pancreas transplantation and control of ocular complications in alloxan-induced diabetic rats

PURPOSE

The impact of pancreas transplantation (PT) on the progression of eye disease is still controversial. This study evaluated the course of retinopathy in transplanted rats in two different diabetic stages.

METHODS

Sixty inbred male Lewis rats were assigned to four experimental groups: NC-15 nondiabetic control rats; DC-15 untreated diabetic control rats; PT1-15 diabetic rats that received syngeneic pancreas transplants 2 weeks after alloxan diabetes induction; PT2-15 diabetic rats that received pancreas transplants 12 weeks after diabetes onset. Clinical and laboratory parameters and lens opacity were examined in all rats prior to treatment and at 1-, 6-, and 12-months follow-up. Nucleated eyes from five rats in each group processed for ultrastructural study of the retinal at 6 and 12 months after PT or at follow-up.

RESULTS

Cataracts were observed in 20%, 60%, and 100% of DC rats at 1-, 6-, and 12-months follow-up, respectively. Early PT (2 weeks) significantly reduced the prevalence of this complication but not late (12 weeks) PT. PT1 rats also showed improved ultrastructure of the superficial and deep capillary plexuses of the retina, and of Müller cells, compared with DC and PT2. In the last group, retinopathy continued to evolve despite successful PT.

CONCLUSION

Our results suggested that prevention of diabetic ocular lesions by PT was closely dependent on earlier performance of the procedure.

Comparison of pancreas-transplanted type 1 diabetic patients with portal-venous versus systemic-venous graft drainage: impact on glucose regulatory hormones and the growth hormone/insulin-like growth factor-I axis

CONTEXT

Pancreas grafts can be drained through the iliac vein (systemic drainage) or the portal vein.

OBJECTIVE

We hypothesized that normalization of portal insulin in patients with portal pancreas graft drainage stimulates the GH/IGF-I axis and thereby contributes to glucose control.

METHODS

We compared patients after combined kidney and pancreas transplantation with portal drainage (n = 7) to patients with systemic drainage of the pancreas graft (n = 8) and nondiabetic controls (n = 8). Overnight fasting sera were analyzed for free and total IGF-I and IGF-binding proteins. Glucose regulatory hormones were examined after an oral glucose tolerance test and GH after stimulation with GHRH.

RESULTS

Systemic drainage led to higher basal and stimulated insulin levels than portal drainage (P < 0.05), but increments in response to oral glucose were reduced in both transplanted groups (P < 0.05 vs. controls). However, glucose tolerance was similar in all groups. Circulating free and total IGF-I and IGF-binding protein-3 were similar to control levels in the systemic drainage group but elevated in the portal drainage group (P < 0.05). Consistently, the GH response was reduced in the portal drainage group (P < 0.05 vs. controls) and correlated inversely with free IGF-I (r = -0.63, P < 0.05).

CONCLUSION

Portal drainage of pancreatic endocrine secretion in pancreas graft recipients raises IGF-I and lowers GH secretion. These changes might explain that glucose regulation is maintained despite lower peripheral insulin levels, compared with patients with systemic graft drainage and nondiabetic control subjects.

Pancreas transplantation prevents cellular oxidative stress in kidneys of alloxan-induced diabetic rats

PURPOSE

Oxidative stress is one of the most important mechanisms to explain genesis of the complications in the chronic progression of diabetes. In this investigation we studied the effects of pancreas transplantation (PT) on the imbalance caused by excessive production of free oxygen radicals by antioxidant defenses of rats with serious chronic hyperglycemia induced by alloxan.

METHODS

Ninety inbred male Lewis rats were randomly distributed into three groups: NC-30 nondiabetic controls; DC-30 diabetic controls without any treatment; PT-30 diabetic rats undergoing syngeneic PT from normal donor Lewis rats. Each experimental group was then split into three subgroups of 10 animals for sacrifice after 1, 3, or 6 months. Clinical and laboratory parameters from all rats as well as lipid hydroperoxide (LPO) concentrations and renal tissue enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were recorded for all rats.

RESULTS

Successful PT corrected clinical and laboratory alterations in diabetic rats with sustained normoglycemia throughout the study. A significant increase in LPO concentration and a marked reduction in SOD and CAT enzyme activity were observed in DC rats; there was no significant variation in renal tissue GSH-Px in this group. However, alterations in DC rats were completely restored from 1st month after PT; all evaluated enzyme levels did not significantly differ (P < .01) from those in NC controls.

CONCLUSION

Successful PT controlled cellular oxidative stress in diabetic kidneys, which may prevent chronic lesions.

Corneal confocal microscopy detects early nerve regeneration after pancreas transplantation in patients with type 1 diabetes

OBJECTIVE

Corneal confocal microscopy (CCM) is a rapid, noninvasive, clinical examination technique that quantifies small nerve fiber pathology. We have used it to assess the neurological benefits of pancreas transplantation in type 1 diabetic patients.

RESEARCH DESIGN AND METHODS

In 20 patients with type 1 diabetes undergoing simultaneous pancreas and kidney transplantation (SPK) and 15 control subjects, corneal sensitivity was evaluated using noncontact corneal esthesiometry, and small nerve fiber morphology was assessed using CCM.

RESULTS

Corneal sensitivity (1.54 +/- 0.28 vs. 0.77 +/- 0.02, P < 0.0001), nerve fiber density (NFD) (13.8 +/- 2.1 vs. 42 +/- 3.2, P < 0.0001), nerve branch density (NBD) (4.04 +/- 1.5 vs. 26.7 +/- 2.5, P < 0.0001), and nerve fiber length (NFL) (2.23 +/- 0.2 vs. 9.69 +/- 0.7, P < 0.0001) were significantly reduced, and nerve fiber tortuosity (NFT) (15.7 +/- 1.02 vs. 19.56 +/- 1.34, P = 0.04) was increased in diabetic patients before pancreas transplantation. Six months after SPK, 15 patients underwent a second assessment and showed a significant improvement in NFD (18.04 +/- 10.48 vs. 9.25 +/- 1.87, P = 0.001) and NFL (3.60 +/- 0.33 vs. 1.84 +/- 0.33, P = 0.002) with no change in NBD (1.38 +/- 0.74 vs. 1.38 +/- 1.00, P = 1.0), NFT (15.58 +/- 1.20 vs. 16.30 +/- 1.19, P = 0.67), or corneal sensitivity (1.23 +/- 0.39 vs. 1.54 +/- 00.42, P = 0.59).

CONCLUSIONS

Despite marked nerve fiber damage in type 1 diabetic patients undergoing pancreas transplantation, small fiber repair can be detected within 6 months of pancreas transplantation using CCM. CCM is a novel noninvasive clinical technique to assess the benefits of therapeutic intervention in human diabetic neuropathy.

Pancreas and islet cell transplantation in diabetes

PURPOSE OF REVIEW

The following review of the field of whole organ pancreas and islet cell transplantation for type 1 diabetes mellitus is timely and relevant, since new findings and outcomes in both fields have emerged in the recent past.

RECENT FINDINGS

Research in the field of whole organ pancreas transplantation is characterized by small advances in knowledge in an established, but not widely used procedure. For islet transplantation, the field is evolving more rapidly. Disappointing clinical trial results, however, have hampered enthusiasm for this procedure. Islet transplantation research recently has focused on delineating possible causes of failure to achieve or sustain insulin independence and innovations to address both this failure and the current shortage of islets for clinical transplantation. Pancreas transplantation research is less innovative at this point, focusing mainly on optimizing clinical results.

SUMMARY

These published findings suggest that at the present time, clinical application of islet transplantation should be limited to clinical trials, focusing on techniques to enhance islet engraftment and survival. Whole organ pancreas transplantation remains the preferable transplant option for the type one diabetic patient.

Management strategies for brittle diabetes

Type 1 diabetes is an intrinsically unstable condition. However, the term "brittle diabetes" is reserved for those cases in which the instability, whatever its cause, results in disruption of life and often recurrent and/or prolonged hospitalization. It affects 3/1000 insulin-dependent diabetic patients, mainly young women. Its prognosis is poor with lower quality of life scores, more microvascular and pregnancy complications and shortened life expectancy. Three forms have been described: recurrent diabetic ketoacidosis, predominant hypoglycemic forms and mixed instability. Main causes of brittleness include malabsorption, certain drugs (alcohol, antipsychotics), defective insulin absorption or degradation, defect of hyperglycemic hormones especially glucocorticoid and glucagon, and above all delayed gastric emptying as a result of autonomic neuropathy. Psychosocial factors are very important and factitious brittleness may lead to a self-perpetuating condition. The assessment of brittle diabetes requires quantification of the variability of blood glucose levels. To quantify instability, measures which have been developed, include Mean Amplitude of the largest Glycemic Excursions (MAGE), Mean Of Daily Differences (MODD), Lability Index (LI), Low Blood Glucose Index (LBGI), Clarke's score, Hyposcore, and continuous blood glucose monitoring. Once psychogenic problems have been excluded, therapeutic strategies require firstly, the treatment of underlying organic causes of the brittleness whenever possible and secondly optimising standard insulin therapy using analogues, multiple injections and consideration of Continuous Subcutaneous Insulin Infusion. Alternative approaches may still be needed for the most severely affected patients. Isolated islet transplantation (IIT), which restores glucose sensing, should be considered in cases of hypoglycaemic unawareness and/or lability especially if the body mass index is < 25, but with current immunosuppressive protocols patients must have normal renal function and preferably no plans for pregnancy. Implantable pumps have advantages for patients who either weigh more than 80 kgs or have abnormalities of kidney or liver function or are highly sensitised.