Retrospective analysis of posttransplantation diabetes mellitus in black renal allograft recipients

Inhibitory effects of immunosuppressive drugs on insulin secretion from HIT-T15 cells and Wistar rat islets

Until recently, islet allotransplantation for type 1 diabetic patients has been largely unsuccessful. Previous pharmacologic studies of single drugs have suggested that one factor contributing to this poor success is toxicity of immunosuppressive drugs on transplanted islets. However, no comprehensive study of agents currently used for islet transplantation has been previously reported. Consequently, we exposed HIT-T15 cells and Wistar rat islets to various concentrations of five immunosuppressive agents for 48 and 24 hr, respectively, and measured glucose-stimulated insulin secretion during subsequent static incubations. Results are expressed as percent reduction of insulin secretion at the lower and upper limits, respectively, of plasma drug concentrations used in clinical transplantation compared with control (no drug exposure). Insulin secretion from HIT-T15 cells was significantly inhibited by 74% and 90% after exposure to methylprednisolone (P<0.05), 11% and 24% after exposure to cyclosporine (P<0.01), 60% and 83% after exposure to mycophenolate (P<0.05), 56% and 63% after exposure to sirolimus (P<0.001), and 10% and 20% after exposure to tacrolimus (P<0.001). Insulin secretion from Wistar rat islets was reduced by 0% and 48% after exposure to mycophenolate (P<0.001) and 20% and 31% after exposure to tacrolimus (P<0.05). No reduction in insulin secretion was observed from either HIT-T15 cells or rat islets after exposure to daclizumab. The results support the hypothesis that toxicity of certain immunosuppressive drugs on beta-cell function plays a role in the poor success of islet allotransplantation. This is especially true of intrahepatically transplanted islets, which are exposed to higher portal concentrations of immunosuppressive agents. These findings support the use of low-dose immunosuppressive drug protocols in clinical islet transplantation.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Altered body composition and fuel metabolism in stable kidney transplant patients on immuno-suppressive monotherapy with cyclosporine A

Glucocorticoid associated altered body fat distribution and muscle wasting are well known following kidney grafting. Whether an immunosuppressive regimen after glucocorticoid withdrawal (i.e. monotherapy with cyclosporine A (CsA)) is associated with normalization of altered body fat distribution and muscle mass remains to be determined. Therefore 18 renal transplant patients (nine males and nine females, 64 +/- 5 (mean +/- SEM) months since transplantation; CsA-monotherapy: 38 +/- 7 months) and 18 age, sex and body mass index matched healthy volunteers were investigated using indirect calorimetry and dual energy X-ray absorptiometry. Lean body mass (LBM) was decreased in patients mostly due to loss of striated muscle in the legs (P < 0.01). Compared to healthy controls, fat mass was increased in head and trunk (P < 0.01) and similar in extremities. Resting energy expenditure expressed per kg LBM was increased by more than 10% (P < 0.05) in patients vs. controls. Plasma insulin and glucose concentrations, total serum cholesterol (C), triglyceride levels and the ratio of LDL-C to HDL-C were all elevated (P < 0.01) in patients as compared with controls. In summary, renal transplant patients on immunosuppressive monotherapy with CsA demonstrate decreased muscle mass despite discontinuation of prednisone therapy. The increased upper body fat might account, at least in part, for peripheral hyperinsulinaemia and dyslipidaemia observed in kidney transplant patients even years after successful transplantation.