Comparison of azathioprine and mycophenolate mofetil for the prevention of acute rejection in recipients of pancreas transplantation

Simultaneous pancreas-kidney transplantation for end-stage renal failure in type 1 diabetes mellitus: Current perspectives

Type 1 diabetes mellitus (T1DM) is one of the important causes of chronic kidney disease (CKD) and end-stage renal failure (ESRF). Even with the best available treatment options, management of T1DM poses significant challenges for cli nicians across the world, especially when associated with CKD and ESRF. Substantial increases in morbidity and mortality along with marked rise in treatment costs and marked reduction of quality of life are the usual consequences of onset of CKD and progression to ESRF in patients with T1DM. Simultaneous pancreas-kidney transplant (SPK) is an attractive and promising treatment option for patients with advanced CKD/ESRF and T1DM for potential cure of these diseases and possibly several complications. However, limited availability of the organs for transplantation, the need for long-term immunosuppression to prevent rejection, peri- and post-operative complications of SPK, lack of resources and the expertise for the procedure in many centers, and the cost implications related to the surgery and postoperative care of these patients are major issues faced by clinicians across the globe. This clinical update review compiles the latest evidence and current recommendations of SPK for patients with T1DM and advanced CKD/ESRF to enable clinicians to care for these diseases.

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.

Increased Telomere Attrition After Renal Transplantation-Impact of Antimetabolite Therapy

Background

The uremic milieu exposes chronic kidney disease (CKD) patients to premature ageing processes. The impact of renal replacement therapy (dialysis and renal transplantation [RTx]) or immunosuppressive treatment regimens on ageing biomarkers has scarcely been studied.

Methods

In this study telomere length in whole blood cells was measured in 49 dialysis patients and 47 RTx patients close to therapy initiation and again after 12 months. Forty-three non-CKD patients were included as controls.

Results

Non-CKD patients had significantly (P ≤ 0.01) longer telomeres than CKD patients. Telomere attrition after 12 months was significantly greater in RTx patients compared to dialysis patients (P = 0.008). RTx patients receiving mycophenolate mofetil (MMF) had a greater (P = 0.007) degree of telomere attrition compared to those treated with azathioprine. After 12 months, folate was significantly higher in RTx patients than in dialysis patients (P < 0.0001), whereas the opposite was true for homocysteine (P < 0.0001). The azathioprine group had lower levels of folate after 12 months than the MMF group (P = 0.003).

Conclusions

The associations between immunosuppressive therapy, telomere attrition, and changes in folate indicate a link between methyl donor potential, immunosuppressive drugs, and biological ageing. The hypothesis that the increased telomere attrition, observed in the MMF group after RTx, is driven by the immunosuppressive treatment, deserves further attention.

The risk of microscopic colitis in solid-organ transplantation patients: a population-based study

BACKGROUND

Microscopic colitis (MC) has not been recognized as a complication of transplantation because patients are on immunosuppressant medications. The objective of this work was to describe the risk of developing MC after solid-organ transplantation.

METHODS

This population-based cohort study identified all cases of MC diagnosed after kidney, kidney and pancreas, or liver transplantation using pathology and transplantation databases. The annual incidence and point prevalence of MC after transplantation was calculated. The incidence rate of MC among transplantation patients was compared with the general population and presented as a Standardized Incidence Ratio (SIR) with 95% confidence intervals.

RESULTS

Seven cases (0.9%) of MC were diagnosed in kidney (n=2), kidney and pancreas (n=1), and liver (n=4) transplantation recipients. The point prevalence of MC was 8.8 per 1000 transplantation recipients. The annual incidence rate of MC in solid-organ transplantation patients was 5.0 cases per 1000 person-years. The SIR of developing MC after transplantation was 50.5 (95% confidence interval 13.6-131.8). The average age of diagnosis of MC was 49.4+/-5.3 years, average time of onset from transplantation was 67.4+/-27.0 months, and the average latency period was 30.1+/-9.0 months. Once diagnosed, all patients responded to MC-specific therapy.

CONCLUSION

Physicians should have a low threshold to investigate for MC in solid-organ transplantation recipients who present with chronic diarrhea because this population is at an increased risk of developing MC.

[Therapy of diabetes mellitus. Pancreas transplantation, islet transplantation, stem cell and gene therapy]

The long-term normalization of glucose metabolism - a prerequisite for the prevention of secondary complications in patients with diabetes mellitus - is only possible by transplantation of a whole pancreas or a reasonable number of islets. An absolute indication for pancreas grafting is given in type 1 diabetic patients with end-stage renal disease. The 1-year survival after simultaneous kidney/pancreas transplantation is, according to the international registry, 94-100% for patients, 89-92% for kidneys and 85-87% for the pancreas. The high success rate with long lasting normalization of glucose metabolism leads to a stabilization and/or amelioration of secondary complications, to an increase in quality of life and, most importantly, to a significant reduction in mortality when compared to diabetic kidney recipients. The indications for islet transplantation are similar to those for pancreatic grafting. Islet grafting is only a minor surgical procedure, but islet isolation is difficult. The 1-year survival for the recipients is 98%, for the islets 82% and for insulin-independency 42%. There is a significant decline of islet function to 10% 5 years after transplantation. Stem cell therapy would provide a definitive treatment solution not only for patients with type 1 diabetes. So far, this therapeutic option is still at an early stage of development.

Mycophenolate mofetil in islet cell transplant: variable pharmacokinetics but good correlation between total and unbound concentrations

The authors investigated the pharmacokinetics of mycophenolic acid over 1 year in 8 Caucasian women undergoing islet cell transplantation. Total mycophenolic acid AUC(0-12) mcg x h/mL before day 60 was 62.1-67.8, declining to 33.6-64.7 thereafter (P = .61). Median total trough concentrations were 1.16-2.90 mcg/mL. Unbound AUC(0-12) was 412-673 ng x h/mL and did not change over time (P = .30). Median percent unbound mycophenolic acid was 0.95% of total concentrations. Individual unbound and total mycophenolic acid concentrations were highly correlated (r2 = 0.94). Total mycophenolic acid trough concentration and total AUC(0-12) were modestly correlated (r2 = 0.65). Intra- and interpatient variability of systemic mycophenolic acid exposure was high. Six patients required dose reductions prior to day 60 due to adverse effects. All subjects achieved insulin independence; 3 later lost graft function. The trend toward higher exposure in the early periods followed by dose reductions suggests that lower initial doses and therapeutic drug monitoring may be necessary.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.