Minimization of steroids in kidney transplantation

Impact of early corticosteroid withdrawal on simultaneous pancreas-kidney transplant long-term outcomes: Single center experience and comparison to the International Pancreas Transplant Registry

BACKGROUND

There remains a paucity of modern data comparing early steroid withdrawal (ESW) versus chronic corticosteroid (CCS) immunosuppression in simultaneous pancreas kidney (SPK) transplant recipients with long-term follow-up. Therefore, the purpose of this study is to assess the effectiveness and tolerability of ESW compared to CCS post-SPK.

METHODS

This was a retrospective single-center matched comparison with the International Pancreas Transplant Registry (IPTR). Patients from University of Illinois Hospital (UIH) represented the ESW group and were compared to those matched CCS patients from the IPTR. Included patients were adult recipients of a primary SPK transplant between 2003 and 2018 within the US receiving rabbit anti-thymocyte globulin induction. Patients were excluded if they had early technical failures, missing IPTR data, graft thrombosis, re-transplant, or positive crossmatch SPK.

RESULTS

A total of 156 patients were matched and included in the analysis. Patients were predominantly African American (46.15%) males (64.1%) with Type 1 diabetes etiology (92.31%). Overall pancreas allograft survival (hazard ratio [HR] = .89, 95% confidence interval [CI] .34-2.30, p = .81) and kidney allograft survival (HR = .80, 95%CI .32-2.03, p = .64) were similar between the two groups. Immunologic pancreas allograft loss was statistically similar at 1-year (ESW 1.3% vs. CCS 0%, p = .16), 5-year (ESW 1.3% vs. CCS 7.7%, p = .16), and 10-year (ESW 11.0% vs. CCS 7.7%, p = .99). The 1-year (ESW 2.6% vs. CCS 0%, p > .05), 5-year (ESW 8.3% vs. CCS 7.0%, p > .05), and 10-year (ESW 22.7% vs. CCS 9.9%, p = .2575) immunologic kidney allograft loss were also statistically similar. There was no difference in 10-year overall patient survival (ESW 76.2% vs. CCS 65.6%, p = .63).

CONCLUSIONS

No differences were found between allograft or patient survival post-SPK when comparing an ESW or CCS protocol. Future assessment is needed to determine differences in metabolic outcomes.

Corticosteroid Dose in Kidney Transplantation and Its Effect on Surgical Complication: A Systematic Review

OBJECTIVES

Although several studies have explored the connection between corticosteroids and renal transplant surgical complications, these studies have overlooked several factors. In addition, no review of the literature, to our knowledge, has been conducted to evaluate corticosteroid dose and incidence of posttransplant surgical complications in these patients. Thus, our objective was to carry out a systematic investigation ofthe correlationbetween corticosteroids and surgical complications in renaltransplant patients.

MATERIALS AND METHODS

A systematic search was conducted on the PubMed and Embase databases from their inception until April 2023. Retrospective and prospective cohort studies were included if they met the association between corticosteroids and surgical complications. The search strategy was performed using MeSH and non-MeSH key words. Terms used in the electronic search included kidney transplant* OR kidney transplant(mesh) AND steroid* OR steroids(mesh) AND complication* OR intraoperative complications(mesh).

RESULTS

From 3274 articles, 8 articles were included in the systematic review. Six studies were conducted as retrospective cohorts and 2 studies as prospective cohorts. The mean age of patients included in the studies was 42.1 years. The studies were conducted between 1981 and 2023. Findings suggested that decreasing the postoperative corticosteroid dosage was associated with a lower incidence of various postoperative surgical complications.

CONCLUSIONS

We investigated the potential benefits of reducing the dose of corticosteroids following kidney transplant. Findings suggested thatreducing the dose of corticosteroids following kidney transplant might be a viable strategy for minimizing the risk of surgical complications. However, it is essential to note that the optimal dosage and duration of corticosteroid therapy after kidney transplant may vary for each patient and should be carefully determined by the health care provider.

Steroid-free maintenance immunosuppression using alemtuzumab in pediatric kidney transplantation: Long-term longitudinal follow-up

BACKGROUND

There is a scarcity of long-term data on steroid-free immunosuppression using alemtuzumab in pediatric kidney transplantation (KTx). This study examines long-term outcomes with alemtuzumab without steroid maintenance therapy in pediatric KTx.

METHODS

From July 2005 to June 2015, 71 pediatric KTx recipients received alemtuzumab without steroid maintenance. They were followed from 4.1 to 14.1 years post KTx.

RESULTS

Patient survival: One child expired with a functioning graft from post-transplant lymphoproliferative disorder (PTLD). Patient survival was 98.6%. Graft survival: Eighteen grafts were lost (16 from chronic rejection). Graft survival at 5 and 10 years was 92.3% and 61.3%, respectively. Rejection: Twenty-three (32.4%) patients were free from T-cell-mediated rejection (TCMR), 16 (22.5%) had >3 episodes. Sixteen (22.5%) were treated for antibody-mediated rejection (AMR). Infection: Twenty-three children developed Epstein-Barr virus (EBV), 5 developed cytomegalovirus (CMV), and 20 developed BK virus infection. Four (5.6%) developed PTLD. Twenty-two (31.0%) required treatment for neutropenia. Growth parameters: Mean height and weight increased by 0.56 and 0.69 SDS (standard deviation score), respectively. Body mass index increased by 5.1 kg/m² at 10 years. Less than 40% required antihypertensive medications at all-time points.

CONCLUSION

Alemtuzumab, without corticosteroid maintenance, offers 98.6% patient survival at 14 years with five and 10-year graft survival of 92.3% and 61.3%, respectively. TCMR and AMR requiring treatment were 67.4% and 22.5%, respectively. CMV, EBV, and BK viremia rates were 7.0%, 32.4%, and 28.2%, respectively. Thirty-one percent were treated for neutropenia; 5.6% developed PTLD. There were improvements in growth parameters and blood pressure.

Antithymocyte induction dosing and incidence of opportunistic viral infections using steroid-free maintenance immunosuppression

BACKGROUND

Currently, there is limited literature evaluating rATG induction dosing and incidence of opportunistic viral infections when using steroid-free maintenance immunosuppression.

METHODS

This single-center, retrospective, study compared high rATG (>4.5 mg/kg) versus low (<4.5 mg/kg) induction dosing and the overall incidence of early opportunistic viral infection at 180 days in the setting of maintenance immunosuppression consisting of tacrolimus, mycophenolate, rapid steroid withdrawal, and a tiered antiviral prevention strategy based on donor-recipient Cytomegalovirus (CMV) serostatus.

RESULTS

A total of 209 patients were included; 76 patients received low-dose and 133 patients received high-dose rATG. Incidence of overall opportunistic viral infection occurred more frequently in patients who received high compared to low dose (29.8% vs 25% p = .030). Incidence of CMV infection was also significantly increased in the high-dose group (31.6% vs 18.4% p = .039). In a multivariable model, rATG dose, as a continuous variable, remained a significant independent predictor of infection along with CMV risk (OR 1.46, 95% CI 1.02-2.09) controlling for age and CMV risk. There were no differences in graft-related outcomes at 180 days.

CONCLUSION

Higher cumulative rATG induction dose was associated with increased incidence of opportunistic viral infections, in the setting of a steroid-free maintenance immunosuppression in the early post-transplant period.

Anti-CD40 antibody 2C10 binds to a conformational epitope at the CD40-CD154 interface that is conserved among primate species

The antagonistic anti-CD40 antibody, 2C10, and its recombinant primate derivative, 2C10R4, are potent immunosuppressive antibodies whose utility in allo- and xenotransplantation have been demonstrated in nonhuman primate studies. In this study, we defined the 2C10 binding epitope and found only slight differences in affinity of 2C10 for CD40 derived from four primate species. Staining of truncation mutants mapped the 2C10 binding epitope to the N-terminal portion of CD40. Alanine scanning mutagenesis of the first 60 residues in the CD40 ectodomain highlighted key amino acids important for binding of 2C10 and for binding of the noncross-blocking anti-CD40 antibodies 3A8 and 5D12. All four 2C10-binding residues defined by mutagenesis clustered near the membrane-distal tip of CD40 and partially overlap the CD154 binding surface. In contrast, the overlapping 3A8 and 5D12 epitopes map to an opposing surface away from the CD154 binding domain. This biochemical characterization of 2C10 confirms the validity of nonhuman primate studies in the translation of this therapeutic antibody and provides insight its mechanism of action.

Ten-year observational follow-up of a randomized trial comparing cyclosporine and tacrolimus therapy combined with steroid withdrawal in living-donor renal transplantation

Although various strategies for steroid withdrawal after transplantation have been attempted, there are few reports of the long-term results of steroid withdrawal regimens in kidney transplantation. Earlier, we reported on a 5-year prospective, randomized, single-center trial comparing the safety and efficacy of cyclosporine (CsA) plus mycophenolate mofetil (MMF) with that of tacrolimus (TAC) plus MMF, when steroids were withdrawn 6 months after kidney transplantation in low-risk patients. We now report the 10-year observational data on the study population. We collected data from the database of the Organ Transplantation Center, Samsung Medical Center for 5 years after completion of the original study (TAC group n = 62; CsA group n = 55). The 10-year patient survival, death-censored graft survival, and acute rejection-free survival did not differ between groups (98% vs 96%; P = 0.49, 78% vs 85%; P = 0.75 and 84% vs 76%; P = 0.14 in the TAC group vs CsA group, respectively). In low-risk patients, there was no difference in long-term patient and graft survival between TAC- and CsA-based late steroid withdrawal regimens that included MMF treatment. More long-term randomized clinical trials are needed to clarify the benefits of late steroid withdrawal in kidney transplantation.

Late Steroid Withdrawal Following AB0-Incompatible Renal Transplantation

BACKGROUND

Current evidence on steroid withdrawal following AB0-incompatible (AB0i) renal transplantation is low. We compared clinical outcomes of patients who agreed to late steroid withdrawal and patients who remained on steroid treatment.

METHODS

Steroid withdrawal was carried out in 11 patients at ≥12 months after transplantation (group W). For comparison, we analyzed 19 patients who remained on triple immunosuppression including steroids (group M). Minimum follow-up was 24 months following transplantation and 12 months after steroid withdrawal.

RESULTS

Baseline characteristics, including observation times, were not different between groups W and M. Graft survival was 100% in group W compared with 84% (16/19) in group M (P = .15). In group M, 1 patient experienced graft failure because of suspected antibody-mediated rejection (ABMR) following temporary cessation of mycophenolate treatment after a diagnosis of cryptococcal pneumonia. Two patients died with functioning graft because of sepsis. In group W, we observed 1 episode of ABMR following steroid withdrawal. At the end of follow-up, estimated glomerular filtration rates (eGFR) were 54 (19-91) versus 60 (15-85) mL/min/1.73 m² in group W versus M, respectively (P = .67).

CONCLUSIONS

Late steroid withdrawal following AB0i transplantation is feasible at a moderate risk of rejection. We recommend close monitoring of renal function and HLA antibodies during and after steroid withdrawal. On the other hand, the occurrence of severe infections causing death and graft loss in patients on triple maintenance immunosuppression including steroids should remind us to consider the overall immunosuppressive burden.

Targeting B Cells and Plasma Cells in Glomerular Diseases: Translational Perspectives

The unique contributions of memory B cells and plasma cells in kidney diseases remain unclear. In this review, we evaluate the clinical experience with treatments directed at B cells, such as rituximab, and at plasma cells, such as proteasome inhibition, to shed light on the role of these two B lineage compartments in glomerular diseases. Specifically, analysis of these targeted interventions in diseases such as ANCA-associated vasculitis, SLE, and antibody-mediated transplant rejection permits insight into the pathogenetic effect of these cells. Notwithstanding the limitations of preclinical models and clinical studies (heterogeneous populations, among others), the data suggest that memory B and plasma cells represent two engines of autoimmunity, with variable involvement in these diseases. Whereas memory B cells and plasma cells appear to be key in ANCA-associated vasculitis and antibody-mediated transplant rejection, respectively, SLE seems likely to be driven by both autoimmune compartments. These conclusions have implications for the future development of targeted therapeutics in immune-mediated renal disease.

Immunosuppressive Medications

Immunosuppressive agents are commonly used in the nephrologist's practice in the treatment of autoimmune and immune-mediated diseases and transplantation, and they are investigational in the treatment of AKI and ESRD. Drug development has been rapid over the past decades as mechanisms of the immune response have been better defined both by serendipity (the discovery of agents with immunosuppressive activity that led to greater understanding of the immune response) and through mechanistic study (the study of immune deficiencies and autoimmune diseases and the critical pathways or mutations that contribute to disease). Toxicities of early immunosuppressive agents, such as corticosteroids, azathioprine, and cyclophosphamide, stimulated intense investigation for agents with more specificity and less harmful effects. Because the mechanisms of the immune response were better delineated over the past 30 years, this specialty is now bestowed with a multitude of therapeutic options that have reduced rejection rates and improved graft survival in kidney transplantation, provided alternatives to cytotoxic therapy in immune-mediated diseases, and opened new opportunities for intervention in diseases both common (AKI) and rare (atypical hemolytic syndrome). Rather than summarizing clinical indications and clinical trials for all currently available immunosuppressive medications, the purpose of this review is to place these agents into mechanistic context together with a brief discussion of unique features of development and use that are of interest to the nephrologist.

A Randomized 2x2 Factorial Clinical Trial of Renal Transplantation: Steroid-Free Maintenance Immunosuppression with Calcineurin Inhibitor Withdrawal after Six Months Associates with Improved Renal Function and Reduced Chronic Histopathology

INTRODUCTION

The two most significant impediments to renal allograft survival are rejection and the direct nephrotoxicity of the immunosuppressant drugs required to prevent it. Calcineurin inhibitors (CNI), a mainstay of most immunosuppression regimens, are particularly nephrotoxic. Until less toxic antirejection agents become available, the only option is to optimize our use of those at hand.

AIM

To determine whether intensive rabbit anti-thymocyte globulin (rATG) induction followed by CNI withdrawal would individually or combined improve graft function and reduce graft chronic histopathology-surrogates for graft and, therefore, patient survival. As previously reported, a single large rATG dose over 24 hours was well-tolerated and associated with better renal function, fewer infections, and improved patient survival. Here we report testing whether complete CNI discontinuation would improve renal function and decrease graft pathology.

METHODS

Between April 20, 2004 and 4-14-2009 we conducted a prospective, randomized, non-blinded renal transplantation trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment = 180). Subsequent maintenance immunosuppression consisted of tacrolimus, a CNI, and sirolimus, a mammalian target of rapamycin inhibitor. We report here the outcome of converting patients after six months either to minimized tacrolimus/sirolimus or mycophenolate mofetil/sirolimus. Primary endpoints were graft function and chronic histopathology from protocol kidney biopsies at 12 and 24 months.

RESULTS

CNI withdrawal (on-treatment analysis) associated with better graft function (p <0.001) and lower chronic histopathology composite scores in protocol biopsies at 12 (p = 0.003) and 24 (p = 0.013) months, without affecting patient (p = 0.81) or graft (p = 0.93) survival, or rejection rate (p = 0.17).

CONCLUSION

CNI (tacrolimus) withdrawal at six months may provide a strategy for decreased nephrotoxicity and improved long-term function in steroid-free low immunological risk renal transplant patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00556933.

Immune minimization strategies in renal transplantation

Very low early rejection rates and excellent short-term kidney allograft outcomes have been the mainstay of forwarding the field of Kidney Transplantation in the last few decades. This progress is mainly achieved by using the current armamentarium of maintenance immunosuppression in different combinations and dosages of calcineurin inhibitors (CNI), corticosteroids and antiproliferative drugs. Metabolic risks and nephrotoxicity of CNIs has led to a search for strategies to minimize their use. Similarly, metabolic risks, mood abnormalities and Cushing-like side effects of steroids have forced physicians and patients alike to try to minimize their use in transplantation. Here, we review the most recent randomized controlled trials of minimization of CNI/steroids in a manner (with incident immunologic risks, state of net immunosuppression and side- effects) that may be helpful to choose the best strategy for the individual patient. New trials testing minimization strategies should include in their design, an assessment of the impact of minimization on development of donor specific antibodies and antibody-mediated rejection as well as long-term outcomes.

A randomized 2×2 factorial trial, part 1: single-dose rabbit antithymocyte globulin induction may improve renal transplantation outcomes

Supplemental digital content is available in the text.

Background

We conducted a randomized and unblinded 2×2 sequential-factorial trial, composed of an induction arm (part 1) comparing single-dose (SD) versus divided-dose rabbit antithymocyte globulin (rATG), and a maintenance arm (part 2) comparing tacrolimus minimization versus withdrawal. We report the long-term safety and efficacy of SD-rATG induction in the context of early steroid withdrawal and tacrolimus minimization or withdrawal.

Methods

Patients (n=180) received 6 mg/kg rATG, SD or four alternate-day doses (1.5 mg/kg/dose), with early steroid withdrawal and tacrolimus or sirolimus maintenance. After 6 months targeted maintenance levels were tacrolimus, 2 to 4 ng/mL and sirolimus, 4 to 6 ng/mL or, if calcineurin inhibitor–withdrawn, sirolimus 8 to 12 ng/mL with mycophenolate mofetil 2 g two times per day. Primary endpoints were renal function (abbreviated modification of diet in renal disease) and chronic graft histopathology (Banff). Secondary endpoints included patient survival, graft survival, biopsy-proven rejection, and infectious or noninfectious complications.

Results

Follow-up averaged longer than 4 years. Tacrolimus or sirolimus and mycophenolate mofetil exposure was identical between groups. The SD-rATG associated with improved renal function (2-36 months; P<0.001) in deceased donor recipients. The SD-rATG associated with quicker lymphocyte, CD4 T cell, and CD4-CD8 recovery and fewer infections. Cox multivariate hazard modeling showed divided-dose–rATG (P=0.019), deceased donor (P=0.003), serious infection (P=0.0.018), and lower lymphocyte count (P=0.001) associated with increased mortality. Patients with all four covariates showed a 27-fold increased likelihood of death (P=0.00002). Chronic graft histopathology, rejection rates, and death-censored graft survival were not significantly different between groups.

Conclusion

The SD-rATG induction improves the 3-year renal function in recipients of deceased donor kidneys. This benefit, along with possibly improved patient survival and fewer infections suggest that how rATG is administered may impact its efficacy and safety.

Steroid-free and steroid withdrawal protocols in heart transplantation: the review of literature

Corticosteroids (CSs) are still the mainstay of induction, rescue, and maintenance in heart transplantation (HTx). However, their use is associated with significant and well-documented side effects usually related to the dose administered and the duration of therapy. Moreover, CSs interfere with the recipient's quality of life and with the active process of graft tolerance. Physicians have been exploring ways to avoid or reduce CSs in association with other immunosuppressive drugs, minimizing side effects and costs. The regimens are classified as steroid-free or steroid withdrawal protocols. The studies analyzed in this review come to similar conclusions as benefits and adverse consequences: steroid-free protocols should be advisable and mandatory in pediatric patients, insulin-dependent diabetes mellitus (IDDM), presence of infection, familial metabolic disorders/obesity, severe osteoporosis, and in the elderly. On the other hand, steroid withdrawal can be successfully achieved in 50-80%, with late better than early withdrawal, no increase in rejection-related mortality, no adverse impact on survival, and probably a better quality of live. Safety and efficacy can certainly be improved by an individualized approach to the transplant recipient.

Influence of steroid maintenance on the outcomes in deceased donor kidney transplant recipients experiencing delayed graft function

Delayed graft function (DGF) is a risk factor for poor long-term graft and patient survival after kidney transplantation. The aim of our study was to explore the beneficial effect of steroid maintenance on outcomes in deceased donor kidney (DDK) transplant recipients with DGF. Using organ procurement and transplant network/United network of organ sharing (OPTN/UNOS) database, we identified adult patients who developed DGF following DDK transplantation performed between January 2000 and December 2008. They received induction with rabbit antithymocyte globulin (r-ATG), alemtuzumab or an interluekin-2 receptor blocker (IL-2B) and were discharged on a calcineurin inhibitor (CNI)/mycophenolate (MMF) based immunosuppression with or without steroids. Adjusted graft and patient survivals were compared between steroid versus no steroid groups for each induction modality. Median follow-up was 29.6 months for the 10,058 patients who developed DGF. There were 5624 patients in r-ATG (steroid, n = 4569, no steroid, n = 1055), 819 in alemtuzumab (steroid, n = 301, no steroid, n = 518) and 3615 in IL-2B (steroid, n = 3380, no steroid, n = 235) groups. Adjusted graft survivals were similar for steroid versus no-steroid groups in patients who received r-ATG (HR: 0.98, 95% CI 0.85-1.13, P = 0.75), alemtuzumab (HR 0.88, 95% CI 0.65-1.19, P = 0.41), and IL-2B (HR 1.01, 95%CI 0.78-1.30, P = 0.96) inductions. The adjusted patient survivals were also similar in r-ATG (HR: 1.19, 95% CI 0.96-1.46, P = 0.19), alemtuzumab (HR: 0.89, 95% CI: 0.57-1.39, P = 0.96), and IL-2R (HR: 1.07, 95% CI: 0.77-1.49, P = 0.96) groups. Our study failed to show any significant graft or patient survival benefits associated with steroid addition to CNI/MMF regimen in DDK recipients with DGF. This may be related to the early immunogenic and non-immunogenic allograft damage from DGF with long-term consequences that are unaltered by steroids.

Maintenance immunosuppression in renal transplantation

The need to maintain allograft recipients on immunosuppression is nearly universal. Immunosuppressive agents used in organ transplantation target one or more steps of the host alloimmune response, specifically processes related to CD4-positive T lymphocytes. Calcineurin-inhibitor based steroid-containing regimens have been the mainstay of maintenance immunosuppression over the last two decades. Newer agents have shown efficacy in this role in recent trials with comparable allograft and patient outcomes. These agents have permitted calcineurin-inhibitor minimization and steroid-sparing strategies in selected groups of patients.

Methylprednisolone treatment increases the proportion of the highly suppressive HLA-DR(+)-Treg-cells in transplanted patients

Methylprednisolone is widely used to improve immune suppression in transplanted patients threatened by acute rejection. Recently, we showed that the suppressive activity of a Treg cell population depends decisively on their percentage of highly suppressive HLA-DR(high+)-Treg cells, which are strongly reduced in rejecting transplant patients. In order to examine whether the composition of the total CD4(+)CD127(low+/-)FoxP3(+)-Treg cell pool with different Treg-subsets (DR(high+)CD45RA(-)-Tregs, DR(low+)CD45RA(-)-Tregs, DR(-)CD45RA(-)-Tregs, DR(-)CD45RA(+)-Tregs) is affected by methylprednisolone bolus therapy we compared the percentages of these four different Treg cell subsets in transplant patients with biopsy proven rejection before and after steroid bolus therapy (n=23). In patients treated with steroid bolus therapy, the percentage of the naïve DR(-)CD45RA(+)-Tregs was significantly decreased, whereas the percentage of the DR(+)CD45RA(-)-Tregs was significantly increased. By that, the strongest increase was detected for the most suppressive DR(high+)CD45RA(-)-Tregs. However, these effects were only temporarily and closely associated to the duration of the bolus therapy. Our results suggest that besides various anti-inflammatory effects on cells of the adaptive and innate immune system, methylprednisolone also has the capacity to enhance the suppressive activity of the total Treg cell pool by increasing its percentage of highly differentiated and highly suppressive DR(high+)CD45RA(-)-Tregs.

The impact of early corticosteroid withdrawal on graft survival in liver transplant recipients

BACKGROUND

There has been increased interest in recent years in reducing or eliminating steroids from the immunosuppression regimen of transplant recipients to reduce adverse effects associated with their use. The purpose of this study was to compare clinical outcomes between early versus late steroid withdrawal after liver transplant to determine the optimal duration of steroid use in this population.

METHODS

This large-scale, retrospective analysis of liver transplants occurred at our institution between 2000 and 2009. Patients were excluded if they were <18 years old, received a multiorgan transplant, or remained on steroids for >1 year. The early steroid withdrawal group had steroids eliminated by 3 months posttransplant; late steroid withdrawal patients had steroids withdrawn between 3 and 12 months posttransplant.

RESULTS

A total of 586 liver transplants occurred during the study period; 330 patients were included in the analysis. Graft survival was significantly lower in the early steroid withdrawal group. There was no difference in patient survival or overall acute rejection. However, the late steroid withdrawal group had a significantly higher rate of early acute rejection episodes. There was no difference with regard to new-onset diabetes after transplant, hyperlipidemia, or cardiovascular events between groups.

CONCLUSION

The results of this study suggest that late corticosteroid withdrawal is associated with better long-term graft survival without increasing the rates of diabetes, hyperlipidemia, or cardiovascular events in liver transplant recipients. A prospective study is warranted to confirm these findings.

Dosing equation for tacrolimus using genetic variants and clinical factors

AIM

To develop a dosing equation for tacrolimus, using genetic and clinical factors from a large cohort of kidney transplant recipients. Clinical factors and six genetic variants were screened for importance towards tacrolimus clearance (CL/F).

METHODS

Clinical data, tacrolimus troughs and corresponding doses were collected from 681 kidney transplant recipients in a multicentre observational study in the USA and Canada for the first 6 months post transplant. The patients were genotyped for 2,724 single nucleotide polymorphisms using a customized Affymetrix SNP chip. Clinical factors and the most important SNPs (rs776746, rs12114000, rs3734354, rs4926, rs3135506 and rs2608555) were analysed for their influence on tacrolimus CL/F.

RESULTS

The CYP3A5*1 genotype, days post transplant, age, transplant at a steroid sparing centre and calcium channel blocker (CCB) use significantly influenced tacrolimus CL/F. The final model describing CL/F (l h(-1)) was: 38.4 ×[(0.86, if days 6-10) or (0.71, if days 11-180)]×[(1.69, if CYP3A5*1/*3 genotype) or (2.00, if CYP3A5*1/*1 genotype)]× (0.70, if receiving a transplant at a steroid sparing centre) × ([age in years/50](-0.4)) × (0.94, if CCB is present). The dose to achieve the desired trough is then prospectively determined using the individuals CL/F estimate.

CONCLUSIONS

The CYP3A5*1 genotype and four clinical factors were important for tacrolimus CL/F. An individualized dose is easily determined from the predicted CL/F. This study is important towards individualization of dosing in the clinical setting and may increase the number of patients achieving the target concentration. This equation requires validation in an independent cohort of kidney transplant recipients.

Ten-year outcome after rapid discontinuation of prednisone in adult primary kidney transplantation

BACKGROUND AND OBJECTIVES

Rapid discontinuation of prednisone after kidney transplantation potentially allows for minimization of steroid-related side effects. Although intermediate-term data with rapid discontinuation of prednisone have been promising, concern still exists regarding long-term outcomes. The 10-year experience is reported herein.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between October 1, 1999 and December 31, 2010, 1241 adult primary kidney transplants (791 living donor and 450 deceased donor) were performed using a protocol in which prednisone is discontinued after postoperative day 5. The 10-year actuarial recipient and graft survival rates and prednisone-related side effects were studied.

RESULTS

Ten-year actuarial patient survival was 71% for living donor transplants and 62% for deceased donor transplants; 10-year graft survival was 61% for living donor transplants and 51% for deceased donor transplants, and was comparable to 10-year Scientific Registry of Transplant Recipients national data. Ten-year death-censored graft survival was 79% for living donor transplants and 80% for deceased donor transplants. Ten-year acute rejection rates were 25% for deceased donor transplants and 31% for living donor transplants; 10-year chronic rejection (interstitial fibrosis/tubular atrophy) rates were 39% for deceased donor transplants and 47% for living donor transplants. For nondiabetic recipients of living donor or deceased donor allografts, the incidence of new-onset diabetes was significantly lower than in historical controls on prednisone (P<0.001). We also found significantly reduced rates of cataracts, avascular necrosis, and cytomegalovirus infection in some subgroups.

CONCLUSIONS

Prednisone-related side effects can be minimized in a protocol incorporating rapid discontinuation of prednisone for maintenance immunosuppression. Ten-year patient and graft outcomes remain acceptable.

Early steroid withdrawal in pediatric renal transplant: five years of follow-up

This prospective, comparative trial investigated the impact on mean change in height standard deviation score (SDS), acute rejection rate, and renal function of early steroid withdrawal in 96 recipients with 5 years of follow-up. Recipients under basiliximab induction and steroid withdrawal (SW: TAC/MMF; n = 55) were compared with a matched steroid control group (SC: TAC/MMF/STEROID, n = 41). SW received steroids until Day 6, SC decreased to 10 mg/m(2) within 2 months post-transplant. Five years after SW, the longitudinal growth (SDS) gain was 1.4 ± 0.4 vs. 1.1 ± 0.3 for SC group (p < 0.02). Height benefits in prepubertal and pubertal status in both groups were demonstrated in the delta growth trends (mixed model; p < 0.01). Biopsy-proven acute rejection in SW was 11% and 17.5%, SC (p: ns). Mean eGFR (ml/min/1.73 m(2)) at 5 years post-transplant was SW 80.6 ± 27.8 vs. 82.6 ± 25.1 for SC (p: ns). The death-censored graft survival rate at 1 and 5 years was 99 and 90% for SW; 98 and 96% for SC (p = ns). PTLD incidence in SW 3.3 vs. 2.5% in SC (p: ns). Five years post-transplant, early steroid withdrawal showed positive impacts on growth, stable renal function without increased acute rejection risk, and PTLD incidence.

Consideration of donor age and human leukocyte antigen matching in the setting of multiple potential living kidney donors

BACKGROUND

Defining living donor (LD)-related risk factors affecting kidney transplant outcome will allow better donor selection and more educated informed consent when there is more than one potential donor. We studied risk factors in a large cohort at a single institution.

METHODS

We reviewed 1632 recipients who underwent LD kidney transplantation at the University of Minnesota between January 1, 1990, and October 1, 2009. Using Cox regression, we studied the effect of donor and recipient risk factors on patient and graft survival. We specifically examined the effect of donor age and human leukocyte antigen (HLA) matching because these are variables that may help clinical decision making when multiple potential donors exist.

RESULTS

Mean donor age was 40.6 years for all transplants; 180 (11%) donors were 55 years or older, and 24 (1.5%) donors were older than 65 years. Mean number of HLA mismatches (per transplant) was 2.9 (29.2% of recipients had one to two HLA mismatches, 39.8% had three to four HLA mismatches, and 25% had five to six HLA mismatches). Donor age more than 65 years, five to six HLA mismatches, delayed graft function, and acute rejection were independent predictors of decreased patient and graft survival. When controlling for recipient age, donor age more than 65 years remained a risk factor for worse outcome.

CONCLUSIONS

Our data suggest that advanced donor age (>65 years) and degree of HLA mismatch (≥5) are independent donor-related risk factors associated with worse outcome. When multiple potential LDs exist, it may be ideal to attempt to use a donor younger than 65 years and with less than five HLA mismatches.

Finding the right time for weaning off immunosuppression in solid organ transplant recipients

Solid organ transplantation (SOT) requires lifelong immunosuppression (IS) to prevent rejection and graft loss. The currently adopted immunosuppressive protocols are numerous and are based on the administration of at least two molecules with diverse mechanisms of action. Owing to the fact that the majority of immunosuppressants act non-selectively, the immune system is normally oversuppressed, and as a result is less able to both defend the host against infection and to control the spread of malignant cells. Consequently, long-term IS is burdened by chronic toxicity, which may be highly invalidating and may significantly influence patient's quality of life, compliance to treatment, overall success rate, and patient and graft survival. In an ideal scenario, SOT recipients should initially receive just enough IS to favor the onset of clinical operational tolerance (COT), a condition where the immune system of the host does not attack the graft in the absence of any immunosuppressant. COT has been documented after liver transplantation (LT) and renal transplantation (RT). First, COT was accidentally detected in patients who were nonadherent to treatment and who spontaneously decided to stop all IS without any medical guidance or surveillance. Later, it was described in recipients who required IS withdrawal following the occurrence of malignant diseases. Based on strikingly convincing experimental data, several tolerogenic protocols have recently been applied in patients but overall the results have been disappointing. The current literature demonstrates that COT can be safely achieved in stable LT recipients, with completely different strategies. Importantly, the onset of an episode of acute rejection during the attempt of IS withdrawal would not worsen the clinical outcome. On the contrary, COT remains a major challenge after RT because the onset of acute rejection will substantiate in graft loss. Currently, a major field of investigation aims to define markers of COT, which will allow the selection of individuals who are more prone to develop COT. Preliminary results in both RT and LT have just been announced; however, these markers will require validation in prospective studies.

Influence of African-American ethnicity on acute rejection after early steroid withdrawal in primary kidney transplant recipients

BACKGROUND AND PURPOSE

The influence of African-American ethnicity on outcomes of kidney transplant recipients subjected to early steroid withdrawal remains controversial. Recent studies that suggest no higher risk among African Americans may be biased by recruitment of relatively small number of African Americans or by patient selection. We compared outcomes of African Americans to non-African Americans in a center in which early steroid withdrawal has become the standard of practice.

METHODS

This was a single-center prospective study of 133 consecutive patients receiving primary kidney transplants between January 2006 and December 2008, followed for >or=3 months, and managed with a similar immunosuppression regimen that included induction antibody therapy, tacrolimus, mycophenolate mofetil, and withdrawal of steroids on postoperative day 5. Acute rejection and other outcomes were compared in African-American patients (n = 55) and compared with those of non-African-American patients (n = 78).

RESULTS

During the first 12 months after early steroid withdrawal, African-American patients experienced a significantly higher cumulative incidence of acute rejection than non-African Americans (23.6% vs 7.7%; P = .020). Using multivariate logistic regression, ethnicity (odds ratio 3.33; P = .047) and HLA mismatch (odds ratio 1.44; P = .041) were significantly correlated with acute rejection independent of recipient age, gender, historical peak panel reactive antibody level (PRA) or PRA at time of transplant, time on dialysis, or donor source.

CONCLUSIONS

African Americans are at increased risk of acute rejection after early steroid withdrawal, particularly when they receive kidneys from poorly matched donors.

Late steroid withdrawal after ABO blood group-incompatible living donor kidney transplantation: high rate of mild cellular rejection

BACKGROUND

Little is known about the safety of steroid withdrawal after ABO blood group-incompatible living donor kidney transplantation.

METHODS

Between September 2005 and November 2007, a total of 15 patients were successfully transplanted over the blood group barrier in our transplantation centers. Similarly to transplant recipients with normal immunological risk, we aimed to taper and eventually stop oral prednisone because of the well-known negative impact of steroids on cardiovascular morbidity and mortality, which in turn is limiting graft survival.

RESULTS

Up to now, patient and graft survival is 100% after a median follow-up of 839 days (range, 513-1281 days). On the basis of serial protocol biopsies, late steroid withdrawal could successfully be performed in only 5 of 11 patients. Nevertheless, the remaining 6 patients showed histologic signs of mild and subclinical acute rejection shortly after complete withdrawal or even during steroid tapering.

CONCLUSIONS

With this elevated risk of at least subclinical acute rejection after late steroid withdrawal, we propose that steroid withdrawal in ABO blood group-incompatible kidney graft recipients should only be performed after a protocol biopsy showing normal tissue and together with a thorough clinical and in doubtful cases also histologic follow-up.

Effects of steroid avoidance and novel protocols on growth in paediatric renal transplant patients

The vast majority of kidney transplant recipients undergo triple maintenance immunosuppression that includes the use of steroids. Irrespective of their long history in organ transplantation and proven efficacy in preventing acute graft rejection, steroids exhibit an unfavourable toxicity profile, including growth retardation in children. Given these negative effects, therapeutic approaches that will substantially decrease patients' exposure to steroids have been considered. The planned approaches included alternate day administration, rapid or late steroid withdrawal at the pre-scheduled time after transplantation and complete steroid avoidance. All three of these strategies have been tested in single- or multicentre studies and shown to have distinct clinical advantages in terms of decreasing the incidence and severity of specific adverse events. However, the safety of these protocols could not be universally proven. The Stanford study showed that a complete steroid avoidance under the "cover" of tacrolimus, mycophenolate mofetil and extended daclizumab induction is a very effective regimen for obtaining an improvement in post-transplantation growth. The recently reported international randomized TWIST trial demonstrated growth improvement as early as 6 months post-transplantation. These protocols may potentially enable paediatric renal graft recipients to safely avoid steroid exposure.

[Transplantation without corticosteroids]

Used in kidney transplantation to prevent and treat rejection, corticosteroids induce a number of adverse side effects over the long term. With the arrival of new immunosuppressive drugs, trials on rapid corticosteroid interruption, a few days or weeks after transplantation, and transplantation without corticosteroids other than the intraoperative bolus, have been conducted in patients at low immunological risk and on particular patient profiles such as children and Afro-Americans. These studies show that early cessation of corticosteroids, whether in these two categories of patients or in patients at low immunological risk, make it possible to reduce the adverse side effects with no harmful influence on patient or graft survival or renal function. The increase in the rejection rate observed with this procedure has no consequences over the medium term after treatment. However, for full success, this strategy must absolutely be carried out under the cover of an induction and an immunosuppressive bitherapy. In these conditions, early interruption of corticosteroids also has beneficial effects over the longer term: it encourages the reduction in the frequency and/or severity of diabetes, weight gain, hypertension, or dyslipidemia and seems to better preserve patients'bone status.