Slowing the progression of chronic allograft nephropathy by conversion from cyclosporine to tacrolimus: a randomized controlled trial

Optimized immunosuppression to prevent graft failure in renal transplant recipients with HLA antibodies (OuTSMART): a randomised controlled trial

BACKGROUND

3% of kidney transplant recipients return to dialysis annually upon allograft failure. Development of antibodies (Ab) against human leukocyte antigens (HLA) is a validated prognostic biomarker of allograft failure. We tested whether screening for HLA Ab, combined with an intervention to improve adherence and optimization of immunosuppression could prevent allograft failure.

METHODS

Prospective, open-labelled randomised biomarker-based strategy (hybrid) trial in 13 UK transplant centres [EudraCT (2012-004308-36) and ISRCTN (46157828)]. Patients were randomly allocated (1:1) to unblinded or double-blinded arms and screened every 8 months. Unblinded HLA Ab+ patients were interviewed to encourage medication adherence and had tailored optimisation of Tacrolimus, Mycophenolate mofetil and Prednisolone. The primary outcome was time to graft failure in an intention to treat analysis. The trial had 80% power to detect a hazard ratio of 0.49 in donor specific antibody (DSA)+ patients.

FINDINGS

From 11/9/13 to 27/10/16, 5519 were screened for eligibility and 2037 randomised (1028 to unblinded care and 1009 to double blinded care). We identified 198 with DSA and 818 with non-DSA. Development of DSA, but not non-DSA was predictive of graft failure. HRs for graft failure in unblinded DSA+ and non-DSA+ groups were 1.54 (95% CI: 0.72 to 3.30) and 0.97 (0.54-1.74) respectively, providing no evidence of an intervention effect. Non-inferiority for the overall unblinded versus blinded comparison was not demonstrated as the upper confidence limit of the HR for graft failure exceeded 1.4 (1.02, 95% CI: 0.72 to 1.44). The only secondary endpoint reduced in the unblinded arm was biopsy-proven rejection.

INTERPRETATION

Intervention to improve adherence and optimize immunosuppression does not delay failure of renal transplants after development of DSA. Whilst DSA predicts increased risk of allograft failure, novel interventions are needed before screening can be used to direct therapy.

FUNDING

The National Institute for Health Research Efficacy and Mechanism Evaluation programme grant (ref 11/100/34).

Calcineurin inhibitor withdrawal or tapering for kidney transplant recipients

BACKGROUND

Calcineurin inhibitors (CNI) can reduce acute transplant rejection and immediate graft loss but are associated with significant adverse effects such as hypertension and nephrotoxicity which may contribute to chronic rejection. CNI toxicity has led to numerous studies investigating CNI withdrawal and tapering strategies. Despite this, uncertainty remains about minimisation or withdrawal of CNI.

OBJECTIVES

This review aimed to look at the benefits and harms of CNI tapering or withdrawal in terms of graft function and loss, incidence of acute rejection episodes, treatment-related side effects (hypertension, hyperlipidaemia) and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 11 October 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) where drug regimens containing CNI were compared to alternative drug regimens (CNI withdrawal, tapering or low dose) in the post-transplant period were included, without age or dosage restriction.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility, risk of bias, and extracted data. Results were expressed as risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 83 studies that involved 16,156 participants. Most were open-label studies; less than 30% of studies reported randomisation method and allocation concealment. Studies were analysed as intent-to-treat in 60% and all pre-specified outcomes were reported in 54 studies. The attrition and reporting bias were unclear in the remainder of the studies as factors used to judge bias were reported inconsistently. We also noted that 50% (47 studies) of studies were funded by the pharmaceutical industry.We classified studies into four groups: CNI withdrawal or avoidance with or without substitution with mammalian target of rapamycin inhibitors (mTOR-I); and low dose CNI with or without mTOR-I. The withdrawal groups were further stratified as avoidance and withdrawal subgroups for major outcomes.CNI withdrawal may lead to rejection (RR 2.54, 95% CI 1.56 to 4.12; moderate certainty evidence), may make little or no difference to death (RR 1.09, 95% CI 0.96 to 1.24; moderate certainty), and probably slightly reduces graft loss (RR 0.85, 95% CI 0.74 to 0.98; low quality evidence). Hypertension was probably reduced in the CNI withdrawal group (RR 0.82, 95% CI 0.71 to 0.95; low certainty), while CNI withdrawal may make little or no difference to malignancy (RR 1.10, 95% CI 0.93 to 1.30; low certainty), and probably makes little or no difference to cytomegalovirus (CMV) (RR 0.87, 95% CI 0.52 to 1.45; low certainty)CNI avoidance may result in increased acute rejection (RR 2.16, 95% CI 0.85 to 5.49; low certainty) but little or no difference in graft loss (RR 0.96, 95% CI 0.79 to 1.16; low certainty). Late CNI withdrawal increased acute rejection (RR 3.21, 95% CI 1.59 to 6.48; moderate certainty) but probably reduced graft loss (RR 0.84, 95% CI 0.72 to 0.97, low certainty).Results were similar when CNI avoidance or withdrawal was combined with the introduction of mTOR-I; acute rejection was probably increased (RR 1.43; 95% CI 1.15 to 1.78; moderate certainty) and there was probably little or no difference in death (RR 0.96; 95% CI 0.69 to 1.36, moderate certainty). mTOR-I substitution may make little or no difference to graft loss (RR 0.94, 95% CI 0.75 to 1.19; low certainty), probably makes little of no difference to hypertension (RR 0.86, 95% CI 0.64 to 1.15; moderate), and probably reduced the risk of cytomegalovirus (CMV) (RR 0.60, 95% CI 0.44 to 0.82; moderate certainty) and malignancy (RR 0.69, 95% CI 0.47 to 1.00; low certainty). Lymphoceles were increased with mTOR-I substitution (RR 1.45, 95% CI 0.95 to 2.21; low certainty).Low dose CNI combined with mTOR-I probably increased glomerular filtration rate (GFR) (MD 6.24 mL/min, 95% CI 3.28 to 9.119; moderate certainty), reduced graft loss (RR 0.75, 95% CI 0.55 to 1.02; moderate certainty), and made little or no difference to acute rejection (RR 1.13 ; 95% CI 0.91 to 1.40; moderate certainty). Hypertension was decreased (RR 0.98, 95% CI 0.80 to 1.20; low certainty) as was CMV (RR 0.41, 95% CI 0.16 to 1.06; low certainty). Low dose CNI plus mTOR-I makes probably makes little of no difference to malignancy (RR 1.22, 95% CI 0.42 to 3.53; low certainty) and may make little of no difference to death (RR 1.16, 95% CI 0.71 to 1.90; moderate certainty).

AUTHORS' CONCLUSIONS

CNI avoidance increased acute rejection and CNI withdrawal increases acute rejection but reduced graft loss at least over the short-term. Low dose CNI with induction regimens reduced acute rejection and graft loss with no major adverse events, also in the short-term. The use of mTOR-I reduced CMV infections but increased the risk of acute rejection. These conclusions must be tempered by the lack of long-term data in most of the studies, particularly with regards to chronic antibody-mediated rejection, and the suboptimal methodological quality of the included studies.

Late Conversion of Kidney Transplant Recipients from Ciclosporin to Tacrolimus Improves Graft Function: Results from a Randomized Controlled Trial

Background

Tacrolimus (TAC) to ciclosporin A (CSA) conversion studies in stable kidney transplant recipients have reported varying effects on graft function. Here we study graft function (eGFR) trajectories using linear mixed models, which provide effect estimates on both slope and baseline level of GFR and offer increased statistical power.

Methods

Secondary analysis of a randomized controlled trial of CSA treated kidney transplant recipients with stable graft function assigned to receive 0.1 mg/kg/day TAC (target 5–8 ng/ml) or to continue CSA based immunosuppression (target 70–150 ng/ml) at a 2:1 ratio. Renal graft function was estimated via the MDRD (eGFR_MDRD) and CKD-EPI (eGFR_CKD-EPI) formulas.

Results

Forty-five patients continued CSA and 96 patients were converted to TAC with a median follow up of 24 months. Baseline demographics (except for recipient age) including native kidney disease, transplant characteristics, kidney graft function, medication use and comorbid conditions did not differ between groups. In respect to long-term renal graft function, linear mixed models showed significantly improved eGFR trajectories (eGFR_MDRD: p<0.001, eGFR_CKD-EPI: p<0.001) in the TAC versus CSA group over 24 months of follow up. Estimated eGFR_CKD-EPI group differences between TAC and CSA were −3.49 (p = 0.019) at 3 months, −5.50 (p<0.001) at 12 months, and −4.48 ml/min/1.73m² (p = 0.003) at 24 months of follow up. Baseline eGFR was a significant predictor of eGFR trajectories (eGFR_MDRD: p<0.001, eGFR_CKD-EPI: p<0.001). Significant effects for randomization group were evident despite short-term trough levels in the supratherapeutic range (27% (n = 26) of TAC patients at week one). Median TAC trough levels were within target range at week 4 after conversion.

Conclusion

Conversion of CSA treated kidney transplant recipients with stable graft function to TAC (target 5–8 ng/ml) showed significantly improved long-term eGFR trajectories when compared to CSA maintenance (target 70–150 ng/ml).

Trial Registration

ClinicalTrials.gov NCT00182559 EudraCT identifier: 2004-004209-98

Can a combined screening/treatment programme prevent premature failure of renal transplants due to chronic rejection in patients with HLA antibodies: study protocol for the multicentre randomised controlled OuTSMART trial

BACKGROUND

Renal transplantation is the best treatment for kidney failure, in terms of length and quality of life and cost-effectiveness. However, most transplants fail after 10 to 12 years, consigning patients back onto dialysis. Damage by the immune system accounts for approximately 50% of failing transplants and it is possible to identify patients at risk by screening for the presence of antibodies against human leukocyte antigens. However, it is not clear how best to treat patients with antibodies. This trial will test a combined screening and treatment protocol in renal transplant recipients.

METHODS/DESIGN

Recipients>1 year post-transplantation, aged 18 to 70 with an estimated glomerular filtration rate>30 mL/min will be randomly allocated to blinded or unblinded screening arms, before being screened for the presence of antibodies. In the unblinded arm, test results will be revealed. Those with antibodies will have biomarker-led care, consisting of a change in their anti-rejection drugs to prednisone, tacrolimus and mycophenolate mofetil. In the blinded arm, screening results will be double blinded and all recruits will remain on current therapy (standard care). In both arms, those without antibodies will be retested every 8 months for 3 years. The primary outcome is the 3-year kidney failure rate for the antibody-positive recruits, as measured by initiation of long-term dialysis or re-transplantation, predicted to be approximately 20% in the standard care group but <10% in biomarker-led care. The secondary outcomes include the rate of transplant dysfunction, incidence of infection, cancer and diabetes mellitus, an analysis of adherence with medication and a health economic analysis of the combined screening and treatment protocol. Blood samples will be collected and stored every 4 months and will form the basis of separately funded studies to identify new biomarkers associated with the outcomes.

DISCUSSION

We have evidence that the biomarker-led care regime will be effective at preventing graft dysfunction and expect this to feed through to graft survival. This trial will confirm the benefit of routine screening and lead to a greater understanding of how to keep kidney transplants working longer.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN46157828.

Compliance with a structured weight loss program is associated with reduced systolic blood pressure in obese patients with chronic kidney disease

BACKGROUND

The effectiveness of lifestyle-based weight loss programs in obese patients with chronic disease has not been widely studied. This study examined the effectiveness of a weight management program (WMP), and sought to determine factors associated with successful weight loss in obese patients with chronic kidney disease (CKD).

METHODS

In this prospective cohort study, all patients with a body mass index (BMI) of >30 kg/m(2) referred to our clinic from January 2005 to December 2008 and who commenced a structured WMP of an energy-reduced renal diet, exercise, and pharmacotherapy were included in the analyses. Changes in body weight and associated variables up to 24 months were assessed with intention-to-treat mixed linear models and predictors of weight loss were identified with multiple linear regression.

RESULTS

One hundred and thirty-five patients (56% male), of mean age 52.2 years and BMI 36.4 kg/m(2) commenced the WMP. Significant weight loss was achieved for all patients at 6, 12, 18, and 24 months. Weight loss at 12 months was predicted by compliance and age, but not by baseline BMI, blood pressure (BP), stage of CKD or pharmacotherapy use. Greater compliance was associated with decreased systolic BP, with no change in mean antihypertensive medication dose.

CONCLUSIONS

Significant weight loss was achieved, demonstrating the effectiveness of the WMP, and compliance with a structured program improved weight loss and systolic BP.

The effects of AEB071 (sotrastaurin) with tacrolimus on rat heterotopic cardiac allograft rejection and survival

BACKGROUND

AEB071 (sotrastaurin) is a specific inhibitor of protein kinase C that prevents T-cell activation. Our previous study demonstrated that AEB071 monotherapy could prevent acute cardiac allograft rejection in rats. Herein, we investigated the effects of AEB071 combined with various doses of tacrolimus (Tac) on the allograft rejection and survival in a rat heart transplantation model.

MATERIALS AND METHODS

Heterotopic cardiac transplantation from Brown-Norway to Lewis rats was performed. Cardiac allograft survival was assessed by monitoring heartbeats in six recipients of each experimental group. Another four recipient rats were selectively sacrificed in each group at d 7 post-transplantation for histologic examination. Serum transaminases, blood urea nitrogen, and creatinine concentrations were measured.

RESULTS

AEB071 monotherapy prolonged allograft mean survival time (MST) compared with the untreated control group. Also a combination of AEB071 and Tac prolonged MST compared with monotherapy groups with higher dose of Tac. In the cardiac graft histology, AEB071 combined with Tac 0.6 mg/kg/d significantly decreased the rejection grade as indicative of decreased inflammatory cell infiltration into the graft. No experimental group was found with any abnormal histologic or serologic evidence of liver and kidney toxicity.

CONCLUSION

AEB071 combined with a smaller dosage of Tac may be clinically possible to establish calcineurin inhibitor (CNI) minimization protocol in solid organ transplantation.

Use of kidney function end points in kidney transplant trials: a systematic review

BACKGROUND

Clinical trials in kidney transplantation are beginning to include markers of kidney function as end points now that traditional outcomes, such as acute rejection, become increasingly rare events. The frequency and type of kidney function end points used are unknown.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Randomized controlled trials in adult kidney transplant recipients reported in 5 major general medical journals and 5 major subspecialty journals in nephrology and transplantation between January 2003 and November 2008.

SELECTION CRITERIA

Inclusion of at least one kidney function end point at least 1 month posttransplant.

RESULTS

133 (79%) of 169 randomized trials identified used a kidney function end point. Of these, 37 (28%) used one or more measures of kidney function as the primary end point, and 81 (61%), as a secondary end point. For the primary end point, 21 (57%) trials used a creatinine-based estimated glomerular filtration rate (eGFR), 18 (49%) used serum creatinine level, and 7 (19%) used measured GFR. Overall, eGFR was an end point in 81 (61%) trials, and measured GFR, in 12 (9%) trials.

LIMITATIONS

This review is limited by the poor quality of the included trials, with many not defining either primary or secondary end points.

CONCLUSIONS

Measures of kidney function are used commonly as surrogate end points in kidney transplant trials, with eGFR becoming more frequently used over time. Further data are needed to properly validate these surrogate end points and fully understand their limitations when designing and interpreting randomized trials.

AEB071--a promising immunosuppressive agent

In the past decades, allograft survival improved because of the development of new and more specific immunosuppressive agents. The introduction of calcineurin inhibitors was a landmark and acute rejection in organ transplantation decreased remarkably. Calcineurin inhibitor such as ciclosporin A inhibits T-cell activation by interfering with the cytosolic protein cyclophilin (immunophilin). This complex of ciclosporin and cyclophilin inhibits calcineurin, which is responsible for activating the transcription of interleukin-2. More recent research revealed a second pathway for T-cell activation, which is mediated by a specific protein kinase C., e.g., protein kinase C theta. AEB071 represents a selective protein kinase C inhibitor with promising potential for immunosuppression in organ transplantation. In pre-clinical studies, AEB071 prolonged allograft survival in kidney and heart transplant models. In human clinical studies, AEB071 reduced severity of psoriasis symptoms and has shown to be safe up to 750 mg single dose treatment. Important adverse events were gastrointestinal disorders and headaches. AEB071 inhibits early T-cell activation via a calcineurin inhibitor independent pathway and is currently investigated as a therapeutic agent to prevent allograft rejection after renal transplantation.

Treatment strategies to minimize or prevent chronic allograft dysfunction in pediatric renal transplant recipients: an overview

Long-term allograft survival poses a major problem in pediatric renal transplantation, with allograft nephropathy being the principal cause of graft failure after the first post-transplant year. The mechanisms of nephron loss resulting in graft dysfunction are multiple, comprising both immunologic factors such as acute and chronic antibody- or T-cell-mediated rejection and non-immunologic components. The latter include peri-transplant injuries and renovascular lesions (renal artery stenosis, thrombosis) as well as cardiovascular risk factors such as arterial hypertension and hyperlipidemia. Another relevant issue leading to progressive nephron loss and declining kidney transplant function is acute and chronic nephrotoxicity induced by the calcineurin inhibitors (CNIs) ciclosporin (cyclosporine microemulsion) and tacrolimus. Furthermore, the presence of an abnormal lower urinary tract as well as bacterial (recurrent pyelonephritis) and viral (cytomegalovirus [CMV], polyomavirus [BK virus; BKV]) infections are crucial factors involved in the incidence of chronic allograft dysfunction and graft failure. Renovascular lesions and lower urinary tract obstruction are typical indicators for surgical intervention. The aim of treatment in pediatric patients with renal failure secondary to a dysfunctional lower urinary tract is to create a sterile, continent, and nonrefluxive reservoir. Surgical techniques such as bladder augmentation and the introduction of intermittent catheterization and anticholinergic therapy have significantly improved graft outcome. Arterial hypertension, another factor responsible for graft function deterioration in pediatric renal transplant recipients, is controlled preferably by the use of angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor antagonists, which are known to possess nephroprotective properties in addition to their potent antihypertensive effects. Although treatment of subclinical rejection with augmented immunosuppression has been associated with better graft survival, an increase of the immunosuppressive level to avoid subclinical rejection should be weighed against the risk of infection. The majority of viral infections affecting kidney allografts are caused by CMV and BKV. Antiviral CMV prophylaxis or pre-emptive therapy with ganciclovir has been shown to have beneficial effects in the pediatric renal transplant population. Treatment of BKV-induced nephropathy is based on reduction of the immunosuppressant therapy, although specific antiviral agents such as cidofovir and leflunomide are known to inhibit BKV. However, cidofovir itself is nephrotoxic and should therefore be administered cautiously to pediatric renal transplant patients. Since CNIs are likewise known for their nephrotoxic effects, especially with long-term use, alteration of the immunosuppressant regimen is necessary in case of deteriorating graft function due to CNI-induced histopathologic changes. Complete CNI avoidance seems inappropriate because, in this situation in pediatric renal transplant recipients, other relatively potent immunosuppressant agents such as lymphocyte-depleting antibodies, which are frequently accompanied by a higher incidence of infections, are needed for rejection prophylaxis. CNI withdrawal and switching of the immunosuppressant regimen from CNI therapy to sirolimus may be an option for some pediatric renal transplant patients with less advanced graft function deterioration. Nevertheless, potential adverse events such as aggravation of proteinuria, hyperlipidemia, myelosuppression, and hypergonadotropic hypogonadism have to be considered, and controlled studies are lacking. At present, an immunosuppressant maintenance therapy composed of low-dose tacrolimus or ciclosporin (CNI minimization) and mycophenolate mofetil with low-dose corticosteroids appears to be the most promising strategy to adopt in pediatric renal transplant recipients at low or normal immunologic risk.

20-year follow-up results of a randomized controlled trial comparing antilymphocyte globulin induction to no induction in renal transplant patients

BACKGROUND

The purpose of this study was to determine the impact of antilymphocyte globulin (ALG)-induction on long-term outcomes of postrenal transplantation.

METHODS

Between January 1985 and January 1986, 123 consecutive renal transplants from deceased donors were performed at a single institution. Patients were randomized into two groups: group 1 (n=63, 40+/-10 year) received cyclosporine (CsA), prednisone, and azathioprine; and group 2 (n=60, 36+/-9 year) received ALG-induction, CsA, and prednisone and delayed initiation (45-90 days posttransplantation) of azathioprine if the CsA dose was less than 4 mg/kg per day. Target CsA trough levels were 150 to 250 ng/mL. Cytomegalovirus prophylaxis was not used. Human leukocyte antigen matching (2.4+/-1.1 vs. 2.6+/-1.2) and cold ischemia time (38+/-8 hr vs. 39+/-9 hr) did not differ.

RESULTS

The incidence of acute rejection was lower in group 2 (28% vs. 75%, P<0.0001). The incidence of cytomegalovirus infection was 10% in group 1 and 18% in group 2 (P=0.41). The incidence of cancer was 22.2% in group 1 and 11.7% in group 2 (P=0.53) and the incidence of lymphoma did not differ (3% vs. 5%, P=0.77). Patient and graft survival in groups 1 and 2 at 1, 10, and 20 years were 100%/79% vs. 100%/93%, 83%/56% vs. 88%/51%, and 64%/43% vs. 54%/47%, respectively (log-rank test, P=0.18 and P=0.078).

CONCLUSION

The use of ALG-induction resulted in a lower incidence of acute rejection and improved graft survival during the first year postrenal transplantation. Patient and graft survival at 20-year follow-up was not affected by ALG-induction.

Five-year study of tacrolimus as secondary intervention versus continuation of cyclosporine in renal transplant patients at risk for chronic renal allograft failure

BACKGROUND

Chronic allograft nephropathy is the most frequent cause of long-term kidney allograft loss. Studies are desperately needed to improve long-term survival. Tacrolimus has been associated with less rejection and better kidney function compared with cyclosporine in clinical trials. This study tested the hypothesis that conversion from cyclosporine to tacrolimus might improve long-term outcomes in patients with chronic allograft damage.

METHODS

In this multicenter Canadian clinical trial, cyclosporine-treated patients with biopsy-proven chronic allograft nephropathy and impaired renal function were randomly assigned (2:1) to convert to tacrolimus or continue on cyclosporine therapy. A total of 106 (70 tacrolimus and 36 cyclosporine treated) patients were followed-up for up to 5 years. The primary outcome was graft survival.

RESULTS

In an intention to treat analysis, subsequent graft (73% vs. 81%, P=0.2835, log-rank test) and patient survival (91% vs. 92%, P=0.8668, log-rank test) were not different between the tacrolimus and cyclosporine groups, respectively. Changes in Chronic Allograft Damage Index scores on protocol biopsies from baseline to 3 years were not different (+0.4+/-1.8 vs. +1.3+/-3.2, P=0.5910, cyclosporine vs. tacrolimus, respectively). There were no significant differences in biopsy-proven acute rejection (6 [8.6%] vs. 2 [5.6%], tacrolimus vs. cyclosporine, respectively, P=0.5906).

CONCLUSIONS

In this study, patients with chronic allograft damage converted from cyclosporine to tacrolimus demonstrated no apparent benefit.

Comparative risk of impaired glucose metabolism associated with cyclosporine versus tacrolimus in the late posttransplant period

New onset diabetes after transplantation (NODAT) and impaired fasting glucose (IFG) are common in kidney transplant recipients (KTRs). Calcinuerin inhibitor (CNI) therapy is a causal risk factor. NODAT is associated with increased mortality and diminished graft survival. We studied the incidence of NODAT and IFG in KTRs before and after a medically indicated switch of CNI therapy from cyclosporine (CsA) to tacrolimus (Tac). The study population consisted of 704 nondiabetic KTRs. Of them, 171 underwent conversion from CsA to Tac (group I) and 533 remained on the CsA since transplantation (Group II). Time-dependent Cox regression and generalized estimating equations were used to account for sequential CNI exposure. NODAT and IFG occurred in 15.2% and 22.1% of group I subjects and 15.6% and 25.8% of group II subjects, respectively (p = 0.90 for NODAT and p = 0.38 for IFG). Accounting for equal follow-up time since conversion from CsA to Tac, the adjusted 5-year NODAT-free survival was 87.4% and 91.4% in group I and group II, respectively (p = 0.90). In conclusion, conversion to Tac, compared to continuous exposure to CsA, carries quantitatively similar risk of impaired glucose metabolism in KTRs in the late posttransplant period.

Early conversion from cyclosporine to tacrolimus increases renal graft function in chronic allograft nephropathy at BANFF stages I and II

Switching from cyclosporine to tacrolimus without steroid pulse was suggested as a therapeutic option in chronic allograft nephropathy (CAN). Thirty-one renal transplant recipients with CAN were prospectively converted from cyclosporine to tacrolimus (group A), in parallel 31 matched cyclosporin A (CsA) patients (group B) without CAN were followed up for 30 months. In six matching patients of groups A and B inulin and para-aminohippurate (PAH)-clearances and mycophenolate were measured over a span of 3 months. Transplant biopsies of group A were scored according to BANFF. While group A presented with transplant dysfunction compared with group B before switching (2.7 +/- 0.16 mg/dl vs. 1.7 +/- 0.09 mg/dl; P < 0.001), transplant function was equal 30 months later: it ameliorated in group A (2.0 +/- 0.18 mg/dl vs. 2.7 +/- 0.16 mg/dl; P < 0.001) and decreased in group B (1.9 +/- 0.13 mg/dl vs. 1.7 +/- 0.09 mg/dl, P < 0.05). Especially, patients with biopsy scores I and II according to BANFF benefited from tacrolimus. Within 3 months, mycophenolate acid (MPA) levels increased under tacrolimus (P < 0.05) whereas inulin and PAH-clearances remained unchanged. At switching, antihypertensive treatment was more intense in group B, but this difference evened out. Adverse side effects were more frequent under tacrolimus. Patients with mild to moderate CAN significantly benefited from switching to tacrolimus. Increased MPA-levels under tacrolimus might have contributed to this effect.

Ciclosporin A tapering monitored by NFAT-regulated gene expression: a new concept of individual immunosuppression

BACKGROUND

The impact of long-term immunosuppression in renal transplant recipients with respect to safety and efficacy remains undetermined. Pharmacodynamic monitoring of the relative reduction of T-cell-specific gene expression in renal transplant recipients treated with cyclosporine A (CsA) was applied in this study.

METHODS

During the study, 20 stable renal transplant recipients with tapered CsA dose and 20 patients with stable CsA dose (matched for age, gender, CsA dose, time after transplantation) were compared for a median period of 18 months (range 6-44). CsA dose was tapered in two stages of 15% each, and the expression of the nuclear factor of activated T cells (NFAT)-regulated genes was determined by reverse-transcription polymerase chain reaction method at CsA trough level and 2 hr after oral uptake.

RESULTS

The initial residual gene expression at 2 hr after CsA intake increased from 6.31% (range 1.30-16.6) to 21.3% (range 6.58-31.8) in patients with CsA dosage reduction. In one patient, the residual gene expression increased more than 40% and resulted in a reversible Banff 1A rejection episode. Blood pressure was significantly lower after CsA dosage reduction (P<0.05). In the pair-matched control group NFAT-regulated gene expression was comparable before and after the follow-up period (7.45% [range 0.21-18.3] vs. 5.87% [range 0.66-13.2]; P=NS). Estimated glomerular filtration rate was significantly worse in the control group (P<0.05).

CONCLUSION

Our observation suggests that the measurement of the relative gene expression in CsA-treated patients is a promising tool to monitor the CsA dosage reduction in long-term renal transplant patients. An increase in residual expression of NFAT-regulated gene expression may result in an acute rejection episode.

Why hasn't eliminating acute rejection improved graft survival?

Although patients with end-stage renal disease can be maintained with dialysis therapy, the superiority of patient survival with renal transplantation makes transplantation the preferred method of renal replacement. Potent immunosuppressive therapies, particularly calcineurin inhibitors, have greatly reduced the incidence of acute rejection. However, long-term allograft survival remains limited. We discuss the impact of acute rejection on long-term allograft survival and discuss other factors leading to late allograft loss, including calcineurin inhibitor toxicity, chronic allograft nephropathy, and BK virus nephropathy, as well as donor and recipient factors associated with long-term allograft loss.