Predicting long-term kidney graft survival: can new trials be performed?

Strategies to Prevent Chronic Allograft Nephropathy in Kidney Transplantation: Focus on Calcineurin Inhibitors

Chronic allograft nephropathy is one of the leading causes of long-term graft failure in kidney transplant recipients. The etiology of this condition is multifactorial, but administration of calcineurin inhibitors is often implicated. With the introduction of newer immunosuppressive agents, strategies for calcineurin inhibitor minimization, avoidance, and withdrawal have been emerging in the literature. These strategies may improve long-term kidney allograft function, but are not without risks. Results from recent clinical trials evaluating the safety and efficacy of these strategies to prevent chronic allograft nephropathy in kidney transplant recipients are summarized and reviewed. Patients who had never received a calcineurin inhibitor or who had cyclosporine withdrawn from their regimens had better kidney function than patients who received or kept receiving a calcineurin inhibitor. The impact of the improvement in kidney function on long-term graft survival remains to be determined. In addition, the benefit in renal function must be weighed against the bone marrow toxicities and/or metabolic complications associated with these regimens.

Living or deceased donor kidney transplantation: a comparison of results and survival rates among Iranian patients

OBJECTIVE

Kidney transplantation is the selective treatment of end-stage renal disease. Although most previous studies have concluded that living kidney donation achieves better graft survival, some factors may limit this type of donation. This study investigated the survival rates of living and deceased donor kidney transplantations among Iranian patients.

MATERIALS AND METHODS

The records of kidney transplantations up to year 2005 were used to compare 50 deceased (group I) with 50 living donor transplants (group II). The recipients were matched by transplantation time. We used SPSS version 15 software to analyze the data.

RESULTS

Group I patients included 28 males and 22 females of mean age of 38 +/- 13 years, while 26 males and 24 females in group II had a mean age of 34.6 +/- 14 years. The rejection and graft nephrectomy rates were significantly higher among group I than group II (P = .01, P = .02). The first-year graft survival was higher in group II (P = .001). The graft survival was significantly lower in recipients who needed a biopsy or dialysis (P = .006 and P = .02, respectively) and higher among those who had a urine volume >4200 mL within the first 24 hours after transplantation (P = .003). Patient survivals were not significantly different between the groups.

CONCLUSION

Living donor kidney transplantations showed higher graft survival and lower acute rejection rates compared with those from deceased donors.

CD127(low) expression in CD4+CD25(high) T cells as immune biomarker of renal function in transplant patients

BACKGROUND

Noninvasive tests measuring cellular immunity could help predict immunologic risk and subsequent allograft dysfunction in transplant patients. CD25 is a promising marker of activation. Recent descriptions of CD127 expression as a discriminating factor between regulatory and activated T cells suggest its potential utility.

METHODS

Expression of CD127 in CD4+CD25 T cells was analyzed by flow cytometry in peripheral blood from 62 renal transplanted patients and 30 healthy controls. Forty patients presented stable graft function and 22 suffered renal failure.

RESULTS

Renal transplant patients showed higher levels of CD127(high) and a lower frequency of CD127(low) than healthy controls (0.63% vs. 0.29% [P<0.001] and 1.4% vs. 2.4% [P<0.001], respectively). However, high frequencies of not only CD127(high) but also CD127(low) showed a significant correlation with serum creatinine levels (P=0.012 and P=0.003, respectively). Allogenic stimulation in vitro increased the frequency of CD127(low) subset in a dose dependent manner. Furthermore, in patients with a high frequency of CD127(low) subset, this consisted mostly of FoxP3 negative cells, discarding their regulatory origin. Median frequency of CD127(low), but not CD127(high), cells showed significant differences between patients with stable function and with renal failure (P<0.005), with 16.7% and 53.1% of individuals above the median CD127(low) value (1.4%), respectively.

CONCLUSION

Quantification of CD127(low) subset through staining of CD4+ T cells with the combined markers CD127/CD25/CD45RO has been demonstrated to be a significant tool for monitoring the outcome course of renal transplant patients.

Pretransplant donor-specific and non-specific immune parameters associated with early acute rejection

BACKGROUND

New immunosuppression protocols have resulted in decreased rates of biopsy-proven acute rejection; however, it is unclear whether recipients without biopsy-proven acute rejection are still at risk for immune complication and chronic allograft dysfunction. The aim of our studies was to determine whether pretransplant immune parameters were associated with posttransplant early acute rejection, unstable creatinine courses, and poor graft outcome.

METHODS

Immune parameters, including human leukocyte antigen (HLA) mismatch, HLA-specific antibodies, global CD4+ cellular response as measured by intracellular adenosine triphosphate (iATP) synthesis, and IFN-gamma precursor frequencies to donor or third-party cells as measured by ELISPOT were determined for a total of 126 kidney recipients treated with a protocol, including rapid discontinuation of prednisone.

RESULTS

The donor specific pretransplant parameters of HLA class I mismatches (P=0.04) and total HLA mismatches (P=0.04) with the donor as well as the pretransplant HLA-donor specific antibodies (P=0.002) were associated with biopsy-proven acute rejection. Higher pretransplant iATP levels, a donor nonspecific parameter, were found associated with biopsy proven acute rejection (P=0.04). Pretransplant iATP levels were significantly greater for recipients with early unstable creatinine levels (P=0.01). Recipients with a pretransplant iATP value greater than 375 ng/ml were 3.67 times more likely to experience acute rejection (P=0.03).

CONCLUSIONS

Pretransplant assessment of donor specific and nonspecific immune parameters may identify recipients who can benefit from closer clinical and immunological surveillance to allow for tailored immunsuppression and selective intervention aimed at optimizing both short and long-term graft outcome.

Risk factors for rising creatinine in renal allografts with 1 and 3 yr survival

BACKGROUND

Determining factors associated with negative slope of inverse creatinine vs. time (1/Cr vs. t) may help prevent a decline in renal allograft function.

METHODS

A total of 1389 adult recipients of primary renal transplants were divided into quartiles based on the slope of 1/Cr vs. t calculated from 6 and 12 months post transplant. A multivariate analysis of risk factors for being in the worst vs. best quartile employed these variables: donor source, HLA mismatch, recipient age, donor age, panel-reactive antibody (PRA), acute rejection (AR), 3-month cyclosporin A (CsA) level, 1-yr CsA level and acute tubular necrosis. Two separate analyses compared risk factors in patients with 1 and 3 yr survival, respectively.

RESULTS

In recipients with > or = 1 yr graft survival, high PRA and AR were associated with negative slopes of 1/Cr vs. t. For those with > or = 3 yr graft survival, both AR and 3-month CsA level > 150 ng/mL were significant risk factors, using both 6- and 12-month slopes. Stratification of AR showed 1 AR episode > or = 6 months and multiple AR episodes carried significant risk for negative slopes.

CONCLUSION

Optimization of allograft function invokes a conundrum between the needs to avoid both AR and high early CsA levels. We support a policy of carefully balancing these two risks.

Target of rapamycin inhibitors (sirolimus and everolimus) for primary immunosuppression of kidney transplant recipients: a systematic review and meta-analysis of randomized trials

BACKGROUND

Target of rapamycin inhibitors (TOR-I) have a novel mode of action but uncertain clinical role. We performed a systematic review of randomized trials where immunosuppressive regimens containing TOR-I were compared with other regimens as initial therapy for kidney transplant recipients.

METHODS

Databases (inception, June 2005) and conference proceedings (1996-2005) were searched. Two independent reviewers assessed trials for eligibility and quality. Results at 1 year, are expressed as relative risk (RR), where values<1 favor TOR-I, or lower dose of TOR-I, and for continuous outcomes are expressed as weighted mean difference (WMD), both expressed with 95% confidence intervals (CI).

RESULTS

Thirty-three trials (142 reports) were included (27 trials of sirolimus, 5 of everolimus, and 1 of head-to-head comparison). When TOR-I replaced calcineurin inhibitors (CNI) (8 trials with 750 participants), there was no difference in acute rejection (RR, 1.03; 95% CI, 0.74-1.44), but serum creatinine was lower (WMD, -18.31 micromol/L; 95% CI, -30.96 to -5.67) and bone marrow more suppressed (leukopenia: RR 2.02; 95% CI, 1.12-3.66; thrombocytopenia: RR, 6.97; 95% CI, 2.97-16.36; and anaemia: RR, 1.67; 95% CI, 1.27-2.20). When TOR-I replaced antimetabolites (11 trials with 3966 participants), acute rejection and cytomegalovirus infection (CMV) were reduced (RR, 0.84; 95% CI, 0.71-0.99; RR, 0.49; 95% CI, 0.37-0.65, respectively), but hypercholesterolemia was increased (RR, 1.65; 95% CI, 1.32-2.06). When low- was compared with high-dose TOR-I, with equal CNI dose (10 trials with 3,175 participants), rejection was increased (RR, 1.23; 95% CI, 1.06-1.43) but calculated glomerular filtration rate (GFR) higher (WMD, 4.27 mL/min; 95% CI, 1.12-7.41), and when lower-dose TOR-I and standard-dose CNI were compared with higher-dose TOR-I and reduced CNI, acute rejection was reduced (RR, 0.67; 95% CI, 0.52-0.88), but calculated GFR was also reduced (WMD, -9.46 mL/min; 95% CI, -12.16 to -6.76). There was no significant difference in mortality, graft loss, or malignancy risk for TOR-I in any comparison.

CONCLUSIONS

TOR-I have been evaluated in four different primary immunosuppressive algorithms: as replacement for CNI and antimetabolites, in combination with CNI at low and high doses, and with a variable dose of CNI. Generally, surrogate endpoints for graft survival favor TOR-I (lower risk of acute rejection and higher GFR), and surrogate endpoints for patient outcomes are worsened by TOR-I (bone marrow suppression and lipid disturbance). Long-term hard-endpoint data from methodologically robust randomized trials are still required.

Target of rapamycin inhibitors (TOR-I; sirolimus and everolimus) for primary immunosuppression in kidney transplant recipients

BACKGROUND

Target of rapamycin inhibitors (TOR-I) (sirolimus, everolimus) are immunosuppressive agents with a novel mode of action but an uncertain clinical role.

OBJECTIVES

To investigate the benefits and harms of immunosuppressive regimens containing TOR-I when compared to other regimens as initial therapy for kidney transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (in The Cochrane Library, issue 2, 2005), MEDLINE (1966-June 2005), EMBASE (1980-June 2005), the specialised register of the Cochrane Renal Group (June 2005)., and contacted authors and pharmaceutical companies to identify relevant studies.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs where drug regimens containing TOR-I were compared to alternative drug regimens in the immediate post-transplant period were included, without age restriction, dosage or language of report.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trials for eligibility and quality, and extracted data. Results are expressed as relative risk (RR) or weight mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

Thirty three trials (142 reports) were included (sirolimus (27), everolimus (5), head-to-head (1)). When TOR-I replaced CNI there was no difference in acute rejection, but serum creatinine was lower (MD -18.31 micromol/L, -30.96 to -5.67), and bone marrow more suppressed (leucopenia: RR 2.02 1.12 to 3.66; thrombocytopenia: RR 6.97 2.97 to 16.36; anaemia: RR 1.67, 1.27 to 2.20). When TOR-I replaced antimetabolites, acute rejection (RR 0.84, 0.71 to 0.99) and cytomegalovirus infection (CMV) (RR 0.49; 0.37 to 0.65) were reduced, but hypercholesterolaemia was increased (RR 1.65, 1.32 to 2.06). For low versus high-dose TOR-I, with equal CNI dose, rejection was increased (RR 1.23, 1.06 to 1.43) but calculated GFR higher (MD 4.27 mL/min, 1.12 to 7.41), and for low-dose TOR-I/standard-dose CNI versus higher-dose TOR-I/reduced CNI, acute rejection (RR 0.67, 0.52 to 0.88) and calculated GFR (MD -9.46 mL/min, -12.16 to -6.76) were reduced. There was no significant difference in mortality, graft loss or malignancy risk for TOR-I in any comparison.

AUTHORS' CONCLUSIONS

TOR-I have been evaluated in four different primary immunosuppressive algorithms; as replacement for CNI and for antimetabolites, in combination with CNI at low and high dose and with variable dose of CNI. Generally, surrogate endpoints for graft survival favour TOR-I (lower risk of acute rejection and higher GFR) and surrogate endpoints for patient outcomes are worsened by TOR-I (bone marrow suppression, lipid disturbance). Long-term hard-endpoint data from methodologically robust RCTs are still needed.

Major effects of delayed graft function and cold ischaemia time on renal allograft survival

BACKGROUND

There is mounting evidence from experimental and clinical studies that the quality of organs from cadaver donors may be influenced by events occurring around the time of brain death, and that these may affect transplant outcome. The aim of this study is to investigate the influence of donor factors on renal allograft outcome in a homogeneous cohort of 518 patients transplanted in a single centre over a 9 year period.

METHODS

Endpoints of the study were delayed graft function (DGF), acute rejection (AR), 1 year graft survival and long-term survival of those grafts that reached 1 year. Multivariate analysis was performed to determine factors that may have influenced the graft outcome indicators.

RESULTS

DGF was the major predictor of graft failure overall with cold ischaemia time (CIT) as an important independent factor. The level of histocompatibility did not influence graft survival. DGF was the major factor affecting 1 year graft survival (P<0.0005) with effects persisting beyond 1 year. DGF was significantly influenced by CIT, donor age, female kidney into male recipient and donor creatinine (P<0.05). Other donor factors and factors associated with donor management were not risk factors for DGF, rejection episodes or graft survival. The risk factors for a number of AR episodes were HLA-DR mismatch and DGF (P<0.005). When grafts surviving for 1 year were considered, only CIT, recipient age and creatinine at 1 year (P<0.05) were found to affect graft survival significantly.

CONCLUSIONS

The results of this analysis of well-matched transplant recipients show that CIT and DGF are the most important predictors of poor short and long-term graft survival. Therefore, in order to improve the long-term survival of renal allografts efforts should focus on limiting CIT and the damage that occurs during this period and on improving our understanding of DGF.

What we CAN do about chronic allograft nephropathy: Role of immunosuppressive modulations

Given the potency of modern immunosuppressive agents, kidney transplantation across alloantingen barriers is a routine phenomenon with excellent 1-year graft survival in most centers. However, the improvement in 1-year graft survival has not been matched by improvements in long-term graft function and chronic allograft nephropathy (CAN) remains the second commonest cause of graft attrition over time. Calcineurin inhibitors, namely cyclosporine A (CyA) and tacrolimus, have been implicated as causal agents in the development of the fibrotic processes that are the hallmarks of CAN. Many studies have, therefore, concentrated on the improvement of long term graft function through the modulation of immunosuppressive therapy. It is the purpose of this review to describe and appraise the available evidence for the prevention and management of CAN through modulation of immunosuppressive agents.

Calcineurin inhibitor withdrawal from sirolimus-based therapy in kidney transplantation: a systematic review of randomized trials

Calcineurin inhibitor (CNI) withdrawal has been used as a strategy to improve renal allograft function, however, it also carries risk of acute rejection. We conducted a systematic review of randomized trials that involved CNI withdrawal from a sirolimus-based immunosuppressive regimen. The search strategy yielded six trials (n = 1047 patients) reported in eight publications. CNI withdrawal from sirolimus-based therapy, was associated with an increased risk of acute rejection (risk difference, 6%; 95% CI 2-10%, p = 0.002) but a higher creatinine clearance (mean difference, 7.49 mL/min; 95% CI 5.08-9.89 mL/min, p < 0.00001) at 1 year compared to continued CNI and sirolimus therapy. Graft loss (relative risk, 0.87; 95% CI 0.46-1.64, p = 0.66) and death (relative risk, 0.88; CI 0.40-1.96, p = 0.76) were similar in both groups at 1 year. Hypertension was significantly reduced in the CNI withdrawal group (relative risk, 0.56; 95% CI 0.40-0.78, p = 0.0006). CNI withdrawal from sirolimus-based therapy is associated with an increased risk of acute rejection in the short term with a significant improvement in renal function and a reduction in hypertension. Longer follow-up is needed to determine if these changes will result in a significant improvement in patient and graft survival.

Accurate Prediction of Kidney Allograft Outcome Based on Creatinine Course in the First 6 Months Posttransplant

Most attempts to predict early kidney allograft loss are based on the patient and donor characteristics at baseline. We investigated how the early posttransplant creatinine course compares to baseline information in the prediction of kidney graft failure within the first 4 years after transplantation. Two approaches to create a prediction rule for early graft failure were evaluated. First, the whole data set was analysed using a decision-tree building software. The software, rpart, builds classification or regression models; the resulting models can be represented as binary trees. In the second approach, a Hill-Climbing algorithm was applied to define cut-off values for the median creatinine level and creatinine slope in the period between day 60 and 180 after transplantation. Of the 497 patients available for analysis, 52 (10.5%) experienced an early graft loss (graft loss within the first 4 years after transplantation). From the rpart algorithm, a single decision criterion emerged: Median creatinine value on days 60 to 180 higher than 3.1 mg/dL predicts early graft failure (accuracy 95.2% but sensitivity = 42.3%). In contrast, the Hill-Climbing algorithm delivered a cut-off of 1.8 mg/dL for the median creatinine level and a cut-off of 0.3 mg/dL per month for the creatinine slope (sensitivity = 69.5% and specificity 79.0%). Prediction rules based on median and slope of creatinine levels in the first half year after transplantation allow early identification of patients who are at risk of loosing their graft early after transplantation. These patients may benefit from therapeutic measures tailored for this high-risk setting.

Strategies to prevent chronic allograft nephropathy in kidney transplantation: focus on calcineurin inhibitors

Chronic allograft nephropathy is one of the leading causes of long-term graft failure in kidney transplant recipients. The etiology of this condition is multifactorial, but administration of calcineurin inhibitors is often implicated. With the introduction of newer immunosuppressive agents, strategies for calcineurin inhibitor minimization, avoidance, and withdrawal have been emerging in the literature. These strategies may improve long-term kidney allograft function, but are not without risks. Results from recent clinical trials evaluating the safety and efficacy of these strategies to prevent chronic allograft nephropathy in kidney transplant recipients are summarized and reviewed. Patients who had never received a calcineurin inhibitor or who had cyclosporine withdrawn from their regimens had better kidney function than patients who received or kept receiving a calcineurin inhibitor. The impact of the improvement in kidney function on long-term graft survival remains to be determined. In addition, the benefit in renal function must be weighed against the bone marrow toxicities and/or metabolic complications associated with these regimens.

Prognostic factors affecting graft and patient survival in cadaveric and living kidney transplantation

Numerous studies have reported various prognostic factors that affect graft and patient survival in living and cadaveric donor kidney transplantation (KT). The purpose of this study was to evaluate the clinical outcomes and prognostic factors affecting graft and patient survivals in living and cadaveric donor KT. Between February 1995 and December 2001, 421 patients who had undergone cadaveric donor KT (group I: 216 cases, 51.3%) or living donor KT (group II: 205 cases, 48.7%), were retrospectively analyzed. Five-year overall graft survival rates in living was significantly better than that in cadaveric donor KT, respectively (P = .0234). There was no difference in patient survival rates between the two groups. Such factors as absence of rejection, female donor, female recipient, adult KT according to recipient age (>14 years), and donor serum creatinine level just before transplantation (< 2.5 mg/dL) were significantly associated with good graft survival among cadaveric donor KT, whereas two factors-absence of rejection and adult KT according to recipient age (>14 years)-influenced graft survival in living donor KT. In multivariate analysis, the only significant prognostic factor related to graft survival was the presence of rejection. In conclusion, we suggest that the presence of rejection is the only factor that impairs graft survival in both cadaveric and living donor KT, while other factors affected graft survival differently in the two groups.

An open randomized study comparing immunosuppression therapy initiated before or after kidney transplantation in haploidentical living recipients

BACKGROUND

Acute rejection is the most important risk factor for graft survival. Although many centers start immunosuppressive therapy days before the surgery in living donors, there is no systematic study concerning the possible advantages of this procedure. In this open randomized study, we compared the efficacy and safety of administration of cyclosporine (CSA; Neoral) and azathioprine before renal transplantation with the administration of the same schema after transplantation, in HLA haploidentical grafts.

METHODS

Sixty renal transplant recipients of an HLA haploidentical allograft from living donors were randomized in two groups: (A) patients that started immunosuppression 3 d before transplantation (n = 30) and (B) those who started the drug schema on the first day after surgery (n = 30). We analyzed the incidence and severity of acute rejection, graft function and infection during the first 3 months after transplantation.

RESULTS

The group of patients who started immunosuppression before had a mean trough level of CSA (299.70 +/- 154.03 ng/mL) in the expected range for an efficacious prevention of acute rejection at the surgery day. Thirteen patients (43.3%) in each group had acute rejection during the follow up (p = 1.00). Two grafts losses (3.3%) occurred, one in each group. Both groups had similar 3-month rejection-free graft survival (56.7 and 56.3%). The incidence of infection was also statistical comparable between groups A and B (56.7 vs. 46.7, p = 0.430). Graft function was similar in patients from both groups.

CONCLUSIONS

Pre-transplant administration of immunosuppression did not reduce the incidence or severity of acute rejection episodes during the first 3 months of transplantation. Immunosuppressive drugs administered before engraftment did not increase the incidence of graft dysfunction or infection.

Long-term renal allograft survival: have we made significant progress or is it time to rethink our analytic and therapeutic strategies?

Impressive renal allograft survival improvement between 1988 and 1995 has been described using projections of half-lives based on limited actual follow up. We aimed, now with sufficient follow up available to calculate real half-lives. Real half-lives calculated from Kaplan-Meier curves for the overall population as well as subsets of repeat transplants and African Americans recipients were examined. Real half-lives were substantially shorter than projected half-lives. As a whole, half-lives have improved by about 2 years between 1988 and 1995 as compared to the earlier projected 6 years of improvement. The improvement seems to be driven primarily by the improvement in graft survival of re-transplants. First transplants showed a cumulative increase in graft survival of less than 6 months. Projected half-lives are a risky estimation of long-term survival especially when based on short actual follow up. First transplant survival has only marginally improved during the early years of post transplant follow up while no significant improvement in long-term survival could be detected between 1988 and 1995. Redirection of attention from early endpoints towards the process of long-term graft loss may be necessary to sustain early gains in the long term.

Comparison of sirolimus-based calcineurin inhibitor-sparing and calcineurin inhibitor-free regimens in cadaveric renal transplantation

INTRODUCTION

This study examines the efficacy and toxicity of sirolimus used as primary immunosuppression in combination with reduced dose tacrolimus (calcineurin inhibitor [CI]-sparing regimen) or mycophenolate mofetil (CI-free regimen) in high-risk cadaveric renal transplantation.

METHODS

Seventy subjects were treated in a quadruple sequential protocol in which 41 were treated with a CI-sparing regimen and 29 were treated with a CI-free regimen. The efficacy and toxicity profiles of these regimens were prospectively monitored and compared.

RESULTS

The study consisted of African Americans (71%), cadaveric donors (100%), donors aged more than 50 years (30%), and patients with delayed graft function (47%). At 1 year, patient survival, graft survival, and incidence of biopsy-proven acute rejection were 98%, 80%, and 10%, respectively, in the CI-sparing group and 100%, 89%, and 7%, respectively, in the CI-free group. Three-month protocol biopsies were performed in 41% (17/41) and 67% (20/29) of the subjects in the CI-sparing and CI-free groups, respectively. Subclinical rejection was detected in 6% (1/17) and 15% (3/20) of the subjects in the CI-sparing and CI-free groups, respectively. Histologic evidence of chronic allograft nephropathy was more prevalent in the CI-sparing group. At 1 year, the mean estimated creatinine clearance was higher in the CI-free group than in the CI-sparing group (72.4 +/-20.0 mL/min vs. 50.5 +/-20.8 mL/min, P <0.01). The two regimens had similar toxicity profiles (hospital readmission, infection, wound complications, and metabolic complications).

CONCLUSIONS

Both sirolimus-based CI-sparing and CI-free regimens are safe and effective in a population with high immunologic risk. The CI-free regimen is associated with better renal function at 1 year post-transplant. Long-term follow-up will aid in determining the risk and benefit ratio of these regimens.

Sirolimus-based therapy following early cyclosporine withdrawal provides significantly improved renal histology and function at 3 years

Graft function and histology are predictive of renal transplant survival. The Rapamune Maintenance Regimen study demonstrated that early cyclosporine (CsA) withdrawal from a sirolimus (SRL)-CsA-steroid (ST) regimen improved renal function and blood pressure. We report the protocol-mandated biopsy findings from that study. Renal transplant patients (n = 430) receiving SRL-CsA-ST were randomized at 3 months after transplantation to remain on SRL-CsA-ST, or to have CsA withdrawn (SRL-ST group). Protocol-mandated biopsies were performed at engraftment and at 12 and 36 months. Two pathologists blindly evaluated 484 biopsies to obtain the Chronic Allograft Damage Index (CADI) scores. At 36 months among patients with serial biopsies (n = 63), the mean CADI score was significantly lower with SRL-ST(4.70 vs. 3.20, p = 0.003), as was the mean tubular atrophy score (0.77 vs. 0.32, p < 0.001). All six components of the CADI score were numerically lower in SRL-ST group; moreover, inflammation and the tubular atrophy scores decreased significantly in the SRL-ST group between 12 and 36 months. The calculated glomerular filtration rate at 36 months was significantly better in the CsA-withdrawal group (54.8 vs. 68.2 mL/min, p = 0.009). In conclusion, withdrawing CsA from the SRL-CsA-ST regimen resulted in improved renal histology and function.

Immunosuppression for Long-Term Maintenance of Renal Allograft Function

The incidence and severity of acute rejection episodes was markedly reduced by the introduction of new immunosuppressive drug regimens for renal transplantation, resulting in improved graft survival at 1 year. However, only modest improvement has been shown in long-term graft function rates. This overview evaluates the efficacy of currently used immunosuppressive drugs and drug combinations for long-term maintenance therapy. Prospective controlled trials rarely extend beyond 5 years; therefore, registry data and retrospective reports have also been employed. From currently available data it may be concluded that the initial beneficial effect of ciclosporin (cyclosporin) is lost 10 years after transplantation. Tacrolimus is an alternative to ciclosporin with a different profile of adverse effects and a higher efficacy in acute rejection treatment. For long-term maintenance, projected half-lives of kidney graft function are in favour of tacrolimus. Mycophenolate mofetil (MMF) has been shown to significantly reduce the incidence of early rejections. However, the improved long-term graft survival reported in retrospective studies has still to be confirmed in controlled trials. There is no convincing evidence for superiority of triple therapy including prednisone (or prednisolone), calcineurin inhibitors and azathioprine/MMF over dual therapy without azathioprine/MMF with respect to long-term outcome. Withdrawal of corticosteroids or calcineurin inhibitors clearly reduces adverse drug effects but carries the risk of acute rejection episodes. Avoidance of corticosteroids by using new immunosuppressive drug combinations may be an option to minimise toxic adverse effects in the future. At present, it seems unjustified to convert renal transplant recipients with stable graft function and tolerable adverse effects from one drug to another solely in expectation of future benefits. Acute early or late rejection episodes and intolerable adverse effects are good reasons for conversions between calcineurin inhibitors or cytotoxic agents. Chronic allograft nephropathy with slowly deteriorating graft function remains an unresolved problem.