mTOR Inhibition and Clinical Transplantation: Pancreas and Islet.

This brief overview discusses the beneficial and deleterious effects of mammalian target of rapamycin (mTOR) inhibitors on ß cells, and how sirolimus- and everolimus-based immunosuppression have impacted on practices and outcomes of pancreas and islet transplantation. Sirolimus was the cornerstone of immunosuppressive regimens in islet transplantation at the turn of the millenium, but utilization of mTOR inhibitors has progressively decreased from greater than 80% to less than 50% of islet transplant recipients in more recent years. For whole pancreas transplantation, mTOR inhibitors were used in approximately 20% of patients in the early 2000s, but this dropped over the years to less than 10% currently. This decrease is arguably due to less well-tolerated side effects without the advantage of better outcomes. Nonetheless, mTOR inhibitors remain extremely valuable as second-line immunosuppressants in pancreas and islet transplantation.

European Renal Best Practice Guideline on kidney donor and recipient evaluation and perioperative care.

The European Best Practice Guideline group (EBPG) issued guidelines on the evaluation and selection of kidney donor and kidney transplant candidates, as well as post-transplant recipient care, in the year 2000 and 2002. The new European Renal Best Practice board decided in 2009 that these guidelines needed updating. In order to avoid duplication of efforts with kidney disease improving global outcomes, which published in 2009 clinical practice guidelines on the post-transplant care of kidney transplant recipients, we did not address these issues in the present guidelines.The guideline was developed following a rigorous methodological approach: (i) identification of clinical questions, (ii) prioritization of questions, (iii) systematic literature review and critical appraisal of available evidence and (iv) formulation of recommendations and grading according to Grades of Recommendation Assessment, Development, and Evaluation (GRADE). The strength of each recommendation is rated 1 or 2, with 1 being a 'We recommend' statement, and 2 being a 'We suggest' statement. In addition, each statement is assigned an overall grade for the quality of evidence: A (high), B (moderate), C (low) or D (very low). The guideline makes recommendations for the evaluation of the kidney transplant candidate as well as the potential deceased and living donor, the immunological work-up of kidney donors and recipients and perioperative recipient care.All together, the work group issued 112 statements. There were 51 (45%) recommendations graded '1', 18 (16%) were graded '2' and 43 (38%) statements were not graded. There were 0 (0%) recommendations graded '1A', 15 (13%) were '1B', 19 (17%) '1C' and 17 (15%) '1D'. None (0%) were graded '2A', 1 (0.9%) was '2B', 8 (7%) were '2C' and 9 (8%) '2D'. Limitations of the evidence, especially the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.We present here the complete recommendations about the evaluation of the kidney transplant candidate as well as the potential deceased and living donor, the immunological work-up of kidney donors and recipients and the perioperative recipient care. We hope that this document will help caregivers to improve the quality of care they deliver to patients. The full version with methods, rationale and references is published in Nephrol Dial Transplant (2013) 28: i1-i71; doi: 10.1093/ndt/gft218 and can be downloaded freely from http://www.oxfordjournals.org/our_journals/ndt/era_edta.html.

Tacrolimus-based, steroid-free regimens in renal transplantation: 3-year follow-up of the ATLAS trial.

BACKGROUND: Long-term use of corticosteroids is associated with considerable morbidity, including cardiovascular and metabolic adverse effects. METHODS: This study evaluated the long-term efficacy and safety of two steroid-free regimens compared with a triple immunosuppressive therapy in renal transplant recipients. This was a 3-year follow-up to a 6-month, open-label, randomized, multicenter study. RESULTS: Data from 3 years were available for 421 (93.3%) of 451 patients in the original intent-to-treat population (143 tacrolimus/basiliximab [Tac/Bas], 139 tacrolimus/mycophenolate mofetil [Tac/MMF], and 139 tacrolimus/MMF/steroids [triple therapy]). In the time interval from 6 months to 3 years after transplantation, the incidence of biopsy-proven acute rejection was low and similar (Tac/Bas, 2.1%; Tac/MMF, 2.2%; triple therapy, 2.2%); Most rejection episodes occurred during the first 6 months of the study. Graft survival was high (Kaplan-Meier estimates: 92.7%, 92.5%, and 92.5%), as was patient survival (93.1%, 96.4%, and 97.0%). There were 10 graft losses (n=2, 4, and 4) and 12 patient deaths (n=5, 2, and 5). Renal function was well preserved throughout the study and similar between groups. There was a trend toward improved cardiovascular risk factors in the Tac/Bas group, including reduced total and low-density lipoprotein cholesterol and lower new-onset insulin use. There were no between-group differences in the incidence or type of adverse events. CONCLUSION: Higher rates of acute rejection early in treatment were seen with the steroid-free regimens, but this did not translate into poorer long-term outcomes, such as graft and patient survival and renal function. A trend for a more favorable cardiovascular risk profile was observed for steroid-free immunosuppression with Tac/Bas.

A multicenter, randomized, double-blind study comparing different FK778 doses (manitimus) with tacrolimus and steroids vs. MMF with tacrolimus and steroids in renal transplantation.

BACKGROUND: This multicenter phase II study in renal transplantation compared 3 concentration-controlled ranges of FK778 (manitimus) with mycophenolate mofetil (MMF) both given in combination with tacrolimus and corticosteroids. METHODS: 364 patients were randomized to 12-month treatment: high-level FK778 group (H, N=87) received 4 x 600 mg/day (4 days) followed by 120 mg/day; mid-level FK778 group (M, N=92) received 3 x 600 mg/day (3 days) followed by 110 mg/day, low-level FK778 group (L, N=92) received 2 x 600 mg/day (2 days) followed by 100 mg/day, and control group received MMF 1 g/day (MMF, N=93). After week 6, FK778 doses were adjusted to trough ranges of 75-125 µg/mL (H), 50-100 µg/mL (M) and 25-75 µg/mL (L). Tacrolimus and steroids were administered at the same dose in each of the 4 groups. RESULTS: Biopsy proven acute rejection (BPAR) at 24 weeks, the primary study endpoint, was comparable in the L (22.8%) and MMF (17.2%) groups but higher in the H (34.5%) and M (29.3%) groups. BPAR at 12 months was comparable in the L (23.9%) and MMF (19.4%) groups but higher in the H (34.5%) and M (31.5%) groups. Graft and patient survival were lowest in the H group and renal function was poorest in the H and M groups. Premature study withdrawal was highest in the H group. CONCLUSIONS: Efficacy was similar between the low-level FK778 and MMF groups. Increased FK778 exposure was poorly tolerated and did not improve efficacy.

Machine perfusion versus cold storage for the preservation of kidneys from donors ≥ 65 years allocated in the Eurotransplant Senior Programme.

BACKGROUND: In the Eurotransplant Senior Programme (ESP), kidneys from donors aged ≥ 65 years are preferentially allocated locally and transplanted into patients aged ≥ 65 years on dialysis. The purpose of this study was to analyse whether the results of transplantation in the ESP can be improved by preservation of organs by hypothermic machine perfusion (MP) compared with simple cold storage (CS). METHODS: Overall, 85 deceased heart-beating donors ≥ 65 years of age were included in this analysis with follow-up until 1 year post-transplant. For each donor, one kidney was randomly assigned to preservation by CS and the contralateral kidney to MP from organ procurement until transplantation. Delayed graft function (DGF), primary non-function (PNF) and 1-year patient and graft survival rates were evaluated as primary and secondary endpoints. RESULTS: The median recipient age was 66 years in both groups and the median cold ischaemia time was 11 h for MP and 10.5 h for CS (P = 0.69). The DGF rate was 29.4% for MP and 34.1% for CS (P = 0.58). Only extended duration of cold ischaemia time was an independent risk factor for the development of DGF (odds ratio 1.2, P < 0.0001). PNF was significantly reduced (3.5% MP versus 12.9% CS, P = 0.02). The 1-year patient and graft survival rates were similar for MP and CS (94% versus 95% and 89 versus 81%, P > 0.05). The 1-year graft survival rate was significantly improved after MP in recipients who developed DGF (84% MP versus 48% CS, P = 0.01). CONCLUSIONS: Continuous pulsatile hypothermic MP for kidneys from donors aged ≥ 65 years can reduce the rate of never-functioning kidneys and improve the 1-year graft survival rate of kidneys with DGF. In this small cohort, the known advantage of MP for the reduction of DGF could not be confirmed, possibly due to relatively short cold ischaemia times.

Kidney donation after circulatory death in a country with a high number of brain dead donors: 10-year experience in Belgium.

Worldwide shortage of standard brain dead donors (DBD) has revived the use of kidneys donated after circulatory death (DCD). We reviewed the Belgian DCD kidney transplant (KT) experience since its reintroduction in 2000. Risk factors for delayed graft function (DGF) were identified using multivariate analysis. Five-year patient/graft survival was assessed using Kaplan-Meier curves. The evolution of the kidney donor type and the impact of DCDs on the total KT activity in Belgium were compared with the Netherlands. Between 2000 and 2009, 287 DCD KT were performed. Primary nonfunction occurred in 1% and DGF in 31%. Five-year patient and death-censored graft survival were 93% and 95%, respectively. In multivariate analysis, cold storage (versus machine perfusion), cold ischemic time, and histidine-tryptophan-ketoglutarate solution were independent risk factors for the development of DGF. Despite an increased number of DCD donations and transplantations, the total number of deceased KT did not increase significantly. This could suggest a shift from DBDs to DCDs. To increase KT activity, Belgium should further expand controlled DCD programs while simultaneously improve the identification of all potential DBDs and avoid their referral for donation as DCDs before brain death occurs. Furthermore, living donation remains underused.

Results of kidney transplantation from controlled donors after cardio-circulatory death: a single center experience.

The aim of this study was to determine results of kidney transplantation (KT) from controlled donation after cardio-circulatory death (DCD). Primary end-points were graft and patient survival, and post-transplant complications. The influence of delayed graft function (DGF) on graft survival and DGF risk factors were analyzed as secondary end-points. This is a retrospective mono-center review of a consecutive series of 59 DCD-KT performed between 2005 and 2010. Overall graft survival was 96.6%, 94.6%, and 90.7% at 3 months, 1 and 3 years, respectively. Main cause of graft loss was patient's death with a functioning graft. No primary nonfunction grafts. Renal graft function was suboptimal at hospital discharge, but nearly normalized at 3 months. DGF was observed in 45.6% of all DCD-KT. DGF significantly increased postoperative length of hospitalization, but had no deleterious impact on graft function or survival. Donor body mass index ≥30 was the only donor factor that was found to significantly increase the risk of DGF (P < 0.05). Despite a higher rate of DGF, controlled DCD-KT offers a valuable contribution to the pool of deceased donor kidney grafts, with comparable mid-term results to those procured after brain death.

Outcome of the living kidney donor.

Renal transplantation from living kidney donors is still relatively marginal in most of the European countries. However, this source of kidney grafts may help to overcome in part the organ donor shortage of cadaveric donors. The living donor strategy implies correct and objective information about donation risks and completely free acceptance of the living candidate of the donation. In this paper, we reviewed the consequences of kidney donation on the living donor health, considering very short term (linked to the surgery), short term (effect of nephrectomy on glomerular filtration rate) and long term (risk of mortality, chronic kidney disease, proteinuria and hypertension) consequences of kidney donation.

Machine perfusion versus cold storage for preservation of kidneys from expanded criteria donors after brain death.

The purpose of this study was to analyze the possible effects of machine perfusion (MP) versus cold storage (CS) on delayed graft function (DGF) and early graft survival in expanded criteria donor kidneys (ECD). As part of the previously reported international randomized controlled trial 91 consecutive heart-beating deceased ECDs--defined according to the United Network of Organ Sharing definition--were included in the study. From each donor one kidney was randomized to MP and the contralateral kidney to CS. All recipients were followed for 1 year. The primary endpoint was DGF. Secondary endpoints included primary nonfunction and graft survival. DGF occurred in 27 patients in the CS group (29.7%) and in 20 patients in the MP group (22%). Using the logistic regression model MP significantly reduced the risk of DGF compared with CS (OR 0.460, P=0.047). The incidence of nonfunction in the CS group (12%) was four times higher than in the MP group (3%) (P=0.04). One-year graft survival was significantly higher in machine perfused kidneys compared with cold stored kidneys (92.3% vs. 80.2%, P=0.02). In the present study, MP preservation clearly reduced the risk of DGF and improved 1-year graft survival and function in ECD kidneys. (Current Controlled Trials number: ISRCTN83876362).

Machine perfusion versus cold storage for the preservation of kidneys donated after cardiac death: a multicenter, randomized, controlled trial.

OBJECTIVE: Hypothermic machine perfusion may improve outcome after transplantation of kidneys donated after cardiac death (DCD), but no sufficiently powered prospective studies have been reported. Because organ shortage has led to an increased use of DCD kidneys, we aimed to compare hypothermic machine perfusion with the current standard of static cold storage preservation. METHODS: Eighty-two kidney pairs from consecutive, controlled DCD donors 16 years or older were included in this randomized controlled trial in Eurotransplant. One kidney was randomly assigned to machine perfusion and the contralateral kidney to static cold storage according to computer-generated lists created by the permuted block method. Kidneys were allocated according to standard rules, with concealment of the preservation method. Primary endpoint was delayed graft function (DGF), defined as dialysis requirement in the first week after transplantation. All 164 recipients were followed until 1 year after transplantation. RESULTS: Machine perfusion reduced the incidence of DGF from 69.5% to 53.7% (adjusted odds ratio: 0.43; 95% confidence interval 0.20-0.89; P = 0.025). DGF was 4 days shorter in recipients of machine-perfused kidneys (P = 0.082). Machine-perfused kidneys had a higher creatinine clearance up to 1 month after transplantation (P = 0.027). One-year graft and patient survival was similar in both groups (93.9% vs 95.1%). CONCLUSIONS: Hypothermic machine perfusion was associated with a reduced risk of DGF and better early graft function up to 1 month after transplantation. Routine preservation of DCD kidneys by hypothermic machine perfusion is therefore advisable.

The value of machine perfusion perfusate biomarkers for predicting kidney transplant outcome.

BACKGROUND: Retrospective evidence suggests that lactate dehydrogenase, aspartate aminotransferase, total glutathione-S-transferase (GST), alanine-aminopeptidase, N-acetyl-ß-D-glucosaminidase (NAG), and heart-type fatty acid binding protein (H-FABP) measured during kidney machine perfusion (MP) could have predictive value for posttransplant outcome. However, these data may be biased due to organ discard based on biomarker measurements, and previous analyses were not adjusted for likely confounding factors. No reliable prospective evidence has been available so far. Nevertheless, some centers already use these biomarkers to aid decisions on accepting or discarding a donor kidney. METHODS: From 306 deceased-donor kidneys donated after brain death or controlled cardiac death and included in an international randomized controlled trial, these six biomarkers were measured in the MP perfusate. In this unselected prospective data set, we tested whether concentrations were associated with delayed graft function, primary nonfunction, and graft survival. Multivariate regression models investigated whether the biomarkers remained independent predictors when adjusted for relevant confounding factors. RESULTS: GST, NAG, and H-FABP were independent predictors of delayed graft function but not of primary nonfunction and graft survival. Lactate dehydrogenase, aspartate aminotransferase, and alanine-aminopeptidase had no independent prognostic potential for any of the endpoints. Perfusate biomarker concentrations had no relevant correlation with cold ischemic time or renal vascular resistance on the pump. CONCLUSIONS: Increased GST, NAG, or H-FABP concentrations during MP are an indication to adjust posttransplant recipient management. However, this study shows for the first time that perfusate biomarker measurements should not lead to kidney discard.

Tacrolimus combined with two different corticosteroid-free regimens compared with a standard triple regimen in renal transplantation: one year observational results.

Side effects of steroid use have led to efforts to minimize their use in transplantation. Two corticosteroid-free regimens were compared with a triple immunosuppressive therapy. Data from the original intent-to-treat (ITT) population (153 tacrolimus/basiliximab [Tac/Bas], 151 tacrolimus/MMF [Tac/MMF], and 147 tacrolimus/MMF/steroids [control]) were analyzed in a 12-month follow-up. Percentage of graft survival were 92.8%, 95.4%, and 95.9% (KM estimates 89.9%, 95.3%, 95.9%), percentage of surviving patients were 98.7%, 98.0%, and 100% (KM estimates 95.9%, 92.8%, and 100%). During months 7-12, graft loss occurred in 3 Tac/Bas, 2 Tac/MMF, and zero control patients, patient deaths in 1 Tac/Bas, 2 Tac/MMF, and zero control, and biopsy-proven acute rejection episodes in 4 Tac/Bas, 3 Tac/MMF, and zero control. Mean serum creatinine at month 12 was 141.9 +/- 69.6 microM, 144.0 +/- 82.1 microM, and 134.5 +/- 71.2 microM (ns). New-onset insulin use in previously non-diabetic patients at month 12 was 1/138, 6/127, and 4/126. Patient and graft survival as well as renal function at 12 months were not different between patient groups, despite considerably higher rates of acute rejection occurring within the first six months after transplantation in both steroid-free patient groups. Tac/Bas therapy might offer benefits in terms of a trend for a more favorable cardiovascular risk profile.

Daclizumab versus antithymocyte globulin in high-immunological-risk renal transplant recipients.

Nondepleting anti-CD25 monoclonal antibodies (daclizumab) and depleting polyclonal antithymocyte globulin (Thymoglobulin) both prevent acute rejection, but these therapies have not been directly compared in a high-risk, HLA-sensitized renal transplant population. We randomly assigned 227 patients, who were about to receive a kidney graft from a deceased donor, to either Thymoglobulin or daclizumab if they met one of the following risk factors: current panel reactive antibodies (PRA) >30%; peak PRA >50%; loss of a first kidney graft from rejection within 2 yr of transplantation; or two or three previous grafts. Maintenance immunosuppression comprised tacrolimus, mycophenolate mofetil, and steroids. Compared with the daclizumab group, patients treated with Thymoglobulin had a lower incidence of both biopsy-proven acute rejection (15.0% versus 27.2%; P = 0.016) and steroid-resistant rejection (2.7% versus 14.9%; P = 0.002) at one year. One-year graft and patient survival rates were similar between the two groups. In a comparison of rejectors and nonrejectors, overall graft survival was significantly higher in the rejection-free group (87.2% versus 75.0%; P = 0.037). In conclusion, among high-immunological-risk renal transplant recipients, Thymoglobulin is superior to daclizumab for the prevention of biopsy-proven acute rejection, but there is no significant benefit to one-year graft or patient survival.

Machine perfusion or cold storage in deceased-donor kidney transplantation.

BACKGROUND: Static cold storage is generally used to preserve kidney allografts from deceased donors. Hypothermic machine perfusion may improve outcomes after transplantation, but few sufficiently powered prospective studies have addressed this possibility. METHODS: In this international randomized, controlled trial, we randomly assigned one kidney from 336 consecutive deceased donors to machine perfusion and the other to cold storage. All 672 recipients were followed for 1 year. The primary end point was delayed graft function (requiring dialysis in the first week after transplantation). Secondary end points were the duration of delayed graft function, delayed graft function defined by the rate of the decrease in the serum creatinine level, primary nonfunction, the serum creatinine level and clearance, acute rejection, toxicity of the calcineurin inhibitor, the length of hospital stay, and allograft and patient survival. RESULTS: Machine perfusion significantly reduced the risk of delayed graft function. Delayed graft function developed in 70 patients in the machine-perfusion group versus 89 in the cold-storage group (adjusted odds ratio, 0.57; P=0.01). Machine perfusion also significantly improved the rate of the decrease in the serum creatinine level and reduced the duration of delayed graft function. Machine perfusion was associated with lower serum creatinine levels during the first 2 weeks after transplantation and a reduced risk of graft failure (hazard ratio, 0.52; P=0.03). One-year allograft survival was superior in the machine-perfusion group (94% vs. 90%, P=0.04). No significant differences were observed for the other secondary end points. No serious adverse events were directly attributable to machine perfusion. CONCLUSIONS: Hypothermic machine perfusion was associated with a reduced risk of delayed graft function and improved graft survival in the first year after transplantation. (Current Controlled Trials number, ISRCTN83876362.)

[First acute rejection episode after renal transplantation: study of the histopathological characteristics according to the immunological risk]. / Premier épisode de rejet aigu après transplantation rénale: étude des caractéristiques histopathologiques en fonction du risque immunologique du patient.

Renal allograft biopsies (n=34) of two different populations of patients according to the immunological risk (high versus low-risk) have been compared retrospectively. The presence of polymorphonuclear leukocytes in peritubular capillaries was more frequent in the high-risk group. The C4d staining was positive in 10% of the low-risk patients and in 50% of the high-risk patients (P=0.03). There were more early graft loss, renal infarctions, interstitial hemorrhage, severe glomerulitis, neutrophilic glomerulitis and Banff III grade rejection in the positive C4d group. In conclusion, half of the immunized patients had a humoral rejection, patients with a C4d positive rejection had more early graft loss and more severe histological lesions.