Sirolimus in Combination with Tacrolimus Is Associated with Worse Renal Allograft Survival Compared to Mycophenolate Mofetil Combined with Tacrolimus

Cyclosporine (CsA) nephrotoxicity is enhanced by sirolimus (SRL). Tacrolimus is perceived to be less nephrotoxic than CsA, and therefore, CsA has been largely replaced by tacrolimus (TAC) when calcineurin inhibitors are used with SRL. We analyzed 44 915 adult renal transplants in the Scientific Renal Transplant Registry (SRTR) from 2000 to 2004. Three thousand five hundred twenty-four (7.8%) patients received a baseline immunosuppressive regimen of TAC/SRL, with an inferior overall (log-rank p<0.001) and death-censored graft survival (p<0.001) as compared to TAC/MMF (N=27 007). This effect was confirmed in multivariate Cox models; the adjusted hazard ratio (AHR) for overall graft loss with TAC/SRL was 1.47 (95% CI=1.32, 1.63) and for CsA/SRL 1.38 (95% CI=1.20, 1.59) relative to TAC/MMF. These effects were most apparent in high-risk transplants. Six-month acute rejection rates were low (11.5-12.6%) and not different between groups. In summary, national data indicate that TAC/SRL as compared to TAC/MMF is associated with significantly worse renal allograft survival in all subgroups of patients and, in particular, higher-risk transplants. These results have to be interpreted in the context of the inherent limitations of any retrospective database analysis and evaluated in context with data from prospective clinical trials.     

Randomized trial of tacrolimus plus mycophenolate mofetil or azathioprine versus cyclosporine oral solution (modified) plus mycophenolate mofetil after cadaveric kidney transplantation: results at 2 years

BACKGROUND: A previous report described the 1-year results of a prospective, randomized trial designed to investigate the optimal combination of immunosuppressants in kidney transplantation. Recipients of first cadaveric kidney allografts were treated with tacrolimus+mycophenolate mofetil (MMF), cyclosporine oral solution (modified) (CsA)+MMF, or tacrolimus+azathioprine (AZA). Results at 1 year revealed that optimal efficacy and safety were achieved with a regimen containing tacrolimus+MMF. The present report describes results at 2 years. METHODS: Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus+MMF, CsA+MMF, or tacrolimus+AZA. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function. Patients were followed up for 2 years. RESULTS: The results at 2 years corroborate and extend the findings of the previous report. Patients randomized to either treatment arm containing tacrolimus experienced improved kidney function. New-onset insulin dependence remained in four, three, and four patients in the tacrolimus+MMF, CsA+MMF, and tacrolimus+AZA treatment arms, respectively. Furthermore, patients with delayed graft function/acute tubular necrosis who were treated with tacrolimus+MMF experienced a 23% increase in allograft survival compared with patients receiving CsA+MMF (P=0.06). Patients randomized to tacrolimus+MMF received significantly lower doses of MMF compared with those administered CsA+MMF. CONCLUSIONS: All three immunosuppressive regi-mens provided excellent safety and efficacy. How-ever, the best results overall were achieved with tacrolimus+MMF. The combination may provide particular benefit to kidney allograft recipients who develop delayed graft function/acute tubular necrosis. Renal function at 2 years was better in the tacrolimus treatment groups compared with the CsA group.     

Immunosuppressive treatment and progression of histologic lesions in kidney allografts

Renal transplantation is the best therapeutic option for patients with end-stage renal disease. Although short-term results are excellent, long-term graft survival has not improved substantially in recent times. Chronic allograft nephropathy (CAN) and death with a functioning graft are the most important causes of graft loss. Recent evidence shows that nephrotoxicity of calcineurin inhibitors contributes to CAN, and the introduction of non-nephrotoxic drugs such as mycophenolate mofetil (MMF) and mammalian target of rapamycin inhibitors may provide new immunosuppressive strategies to improve long-term results after renal transplantation. MMF decreases the risk of developing chronic allograft failure and is useful for treating established CAN, because it has a beneficial effect on allograft fibrosis. Treatment with sirolimus (SRL), a basic immunosuppressive drug given in association with MMF, may offer better renal function, decrease the prevalence of CAN, and downregulate expression of genes responsible for the progression of CAN than treatment with cyclosporine A (CsA). SRL also permits an early elimination of CsA from SRL-CsA-steroid regimens and shows better renal function and improved renal histology without risk of rejection. Notably, this approach improves graft survival at 4 years. Further multicenter studies are needed to determine whether both approaches produce similar results by comparing immunosuppression caused by SRL-based and tacrolimus (TAC)-based treatments. Because TAC is the most commonly used anticalcineurin drug, it is important to compare the effects of steroid-TAC-SRL treatment with and without elimination of TAC. Finally, although caution is needed, the use of non-nephrotoxic immunosuppressive treatment may change the natural history of CAN.     

Kidney function and morphology after short-term combination therapy with cyclosporine A, tacrolimus and sirolimus in the rat.

BACKGROUND: Sirolimus (SRL) may supplement calcineurin inhibitors in clinical organ transplantation. These are nephrotoxic, but SRL seems to act differently displaying only minor nephrotoxic effects, although this question is still open. In a number of treatment protocols where SRL was combined with a calcineurin inhibitor indications of a synergistic nephrotoxic effect were described. The aim of this study was to examine further the renal function, including morphological analysis of the kidneys of male Sprague-Dawley rats treated with either cyclosporine A (CsA), tacrolimus (FK506) or SRL as monotherapies or in different combinations. METHODS: For a period of 2 weeks, CsA 15 mg/kg/day (given orally), FK506 3.0 mg/kg/day (given orally) or SRL 0.4 mg/kg/day (given intraperitoneally) was administered once a day as these doses have earlier been found to achieve a significant immunosuppressive effect in Sprague-Dawley rats. In the 'conscious catheterized rat' model, the glomerular filtration rate (GFR) was measured as the clearance of Cr(EDTA). The morphological analysis of the kidneys included a semi-quantitative scoring system analysing the degree of striped fibrosis, subcapsular fibrosis and the number of basophilic tubules, plus an additional stereological analysis of the total grade of fibrosis in the cortex stained with Sirius Red. RESULTS: CsA, FK506 and SRL all significantly decreased the GFR. A further deterioration was seen when CsA was combined with either FK506 or SRL, whereas the GFR remained unchanged in the group treated with FK506 plus SRL when compared with treatment with any of the single substances. The morphological changes presented a similar pattern. The semi-quantitative scoring was significantly worst in the group treated with CsA plus SRL (P<0.001 compared with controls) and the analysis of the total grade of fibrosis also showed the highest proportion in the same group and was significantly different from controls (P<0.02). The FK506 plus SRL combination showed only a marginally higher degree of fibrosis as compared with controls (P=0.05). CONCLUSION: This rat study demonstrated a synergistic nephrotoxic effect of CsA plus SRL, whereas FK506 plus SRL was better tolerated.     

Immunosuppression with Belatacept‐Based,Corticosteroid‐Avoiding Regimens in De Novo Kidney Transplant Recipients

Current immunosuppressive regimens in renal transplantation typically include calcineurin inhibitors (CNIs) and corticosteroids, both of which have toxicities that can impair recipient and allograft health. This 1‐year, randomized, controlled, open‐label, exploratory study assessed two belatacept‐based regimens compared to a tacrolimus (TAC)‐based, steroid‐avoiding regimen. Recipients of living and deceased donor renal allografts were randomized 1:1:1 to receive belatacept‐mycophenolate mofetil (MMF), belatacept‐sirolimus (SRL), or TAC‐MMF. All patients received induction with 4 doses of Thymoglobulin (6 mg/kg maximum) and an associated short course of corticosteroids. Eighty‐nine patients were randomized and transplanted. Acute rejection occurred in 4, 1 and 1 patient in the belatacept‐MMF, belatacept‐SRL and TAC‐MMF groups, respectively, by Month 6; most acute rejection occurred in the first 3 months. More than two‐thirds of patients in the belatacept groups remained on CNI‐ and steroid‐free regimens at 12 months and the calculated glomerular filtration rate was 8–10 mL/min higher with either belatacept regimen than with TAC‐MMF. Overall safety was comparable between groups. In conclusion, primary immunosuppression with belatacept may enable the simultaneous avoidance of both CNIs and corticosteroids in recipients of living and deceased standard criteria donor kidneys, with acceptable rates of acute rejection and improved renal function relative to a TAC‐based regimen.     

Albuminuria after renal transplantation: maintenance with sirolimus/low-dose tacrolimus vs. mycophenolate mofetil/high-dose tacrolimus

Maintenance immunosuppression with sirolimus (SRL) in renal transplantation has been associated with proteinuria. We report long-term outcomes of kidney transplant recipients maintained on steroid-free regimens, either SRL with low-dose tacrolimus (SRL/L-Tac) or mycophenolate mofetil (MMF) with high-dose tacrolimus (MMF/H-Tac). We conducted a case-matched study of 50 patients receiving MMF/H-Tac, matched 1:2 with 100 patients maintained on SRL/L-Tac. All patients were induced with rabbit antithymocyte globulin followed by early steroid withdrawal. Comparisons were made of patient and graft survival, graft function, acute rejection, and albuminuria. There were no significant differences between the SRL/L-Tac and MMF/H-Tac groups for patient survival, graft survival, occurrence of acute rejection, or graft function. There was no difference in the proportion of patients with albumin/creatinine ratio (ACR) ≥300 μg/mg (19% vs. 20%), but more patients in the SRL group were receiving renin-angiotensin system blocking agents (72% vs. 53%, p = 0.04). Only flushing the donor kidney with histidine-tryptophan-ketoglutarate solution (vs. UW solution) was predictive of albuminuria. Long-term outcomes are similar at our center for kidney transplant patients receiving either SRL/L-Tac or MMF/H-Tac. Although the occurrence of albuminuria was not different, significantly more SRL-treated patients were receiving antiproteinuric medications.     

Mycophenolate mofetil-based immunosuppression with sirolimus in renal transplantation: a randomized, controlled Spare-the-Nephron trial

As part of the Spare-the-Nephron trial, we evaluated the combination mycophenolate mofetil (MMF) and sirolimus (SRL) as a calcineurin inhibitor (CNI)-free regimen for the preservation of renal function in renal allograft recipients. This 2-year, open-label, multicenter trial randomized 299 patients of which 151 were maintained on MMF and a CNI, 148 on MMF plus SRL (n=120, tacrolimus; n=31, cyclosporine). Baseline characteristics including measured (iothalamate) glomerular filtration rate (GFR) were similar between groups. After 1 year, the mean percentage change from baseline in the primary end point of measured GFR was significantly higher in the MMF/SRL group compared with the MMF/CNI group. After 2 years, the change was indistinguishable. Calculated creatinine clearance and GFR were significantly greater with MMF/SRL at 2 years within which biopsy-proven acute rejection (BPAR) occurred in 14 MMF/SRL-treated patients (3 graft losses) and in 17 receiving the MMF/CNI (6 graft losses). Significantly, no patients receiving MMF/SRL but five treated with MMF/CNI died. Thus, compared with MMF/CNI treatment, a 2-year regimen of MMF/SRL resulted in similar measures of renal function but with fewer deaths and a trend to less BPAR and graft loss.     

Synergistic effects of sirolimus with cyclosporine and tacrolimus: analysis of immunosuppression on lymphocyte proliferation and activation in rat whole blood

BACKGROUND: Whole-blood analysis of lymphocyte function was used to investigate the pharmacodynamic (PD) interaction of sirolimus (SRL) with cyclosporine (CsA) or tacrolimus (TRL) in vitro and to determine the relation between PD and pharmacokinetics (PK) of SRL in an in vivo rat model. METHODS: In vitro, experiments involved incubation of increasing concentrations (0.25-25 [corrected] nM) of SRL with either CsA or TRL in rat whole blood. For the in vivo study, rats were orally treated with different doses of SRL alone (1, 3, 5, or 8 mg/kg) or with a combination of 3 mg/kg SRL plus 2.5 or 5 mg/kg CsA. Blood was obtained before and at different times after dosing. Inhibition of lymphocyte proliferation (proliferating cell nuclear antigen [PCNA]) and activation (CD25, CD71, CD11a, CD134) in mitogen-stimulated blood was determined using fluorescence-activated cell sorter analysis. SRL and CsA blood concentrations were determined at the same time points by light chromatography tandem mass spectrometry (LC-MS). RESULTS: In vitro, concentrations of SRL between 0.25-25 [corrected] nM acted synergistically in combination with CsA or TRL at concentrations between 0.25-1.0 [corrected] nM. Higher SRL concentrations did not further increase inhibition of lymphocyte function in these combinations. In vivo, good correlations (r=0.68-0.94) were observed between PD parameters of lymphocyte function and SRL-PK and dose. Increasing SRL doses produced higher blood concentrations, but SRL doses of 8 mg/kg did not further increase inhibition of lymphocyte function. PD effects on lymphocyte function were prolonged, but maximal inhibition was not increased when SRL was applied in combination with CsA as compared to SRL mono therapy. CONCLUSIONS: The results suggest that analysis of lymphocyte function in whole blood may be useful to optimize dosing of SRL in combination with CsA or TRL and that PD monitoring of immunosuppressive drugs will enhance the value of PK monitoring.     

西罗莫司在肝移植术后肾功能异常患者中的应用

目的 探讨西罗莫司替换钙调磷酸酶抑制剂治疗肝移植术后肾功能不全的安全性和有效性.方法 北将肝移植术后发生肾功能不全的62例患者随机分为对照组和转换组.对照组29例,继续采用Tac(或CsA)、MMF及Pred的方案,血Tac(或CsA)浓度调整在治疗窗范围的下限;转换组33例,用SRL替换原方案中的Tac(或CsA),SRL的起始用量为2 mg/d,以后根据血SRL浓度及不良反应作相应调整,Tac(或CsA)减少至原用量的1/3～1/2,3 d后停用,MMF和Pred的用法不变.转换治疗后,对患者的肝肾功能、急性排斥反应及存活率进行随访监测,并观察患者在转换治疗期间发生的不良反应.结果 共有49例患者痊愈或者好转,13例死亡,对照组死亡8例,转换组死亡5例.随访9～51个月,转换组存活患者肝功能稳定,均未发生急性排斥反应.两组存活患者肾功能恢复后均未再出现反复,且转换组患者肾功能恢复时间明显缩短,治疗效果较好.转换组存活患者未发生严重不良反应,与对照组肺部感染发生率的比较,差异无统计学意义(P>0.05).结论 肝移植术后并发肾功能不全时,采用西罗莫司替换原免疫抑制方案中的CNI治疗是安全有效的.     

Immunosuppression for Dual Kidney Transplantation with Marginal Organs: The Old Is Better Yet

Immunosuppressive protocols in dual kidney transplantation (DKT) are based on calcineurin inhibitors (CNI). We wonder whether a CNI-free immunosuppression can improve outcome in older patients receiving a DKT with marginal donor organs. Thirty-six were treated with CsA, MMF and prednisone (CsA group) and 42 with rATG, SRL, MMF and prednisone (SRL group). Incidence of delayed graft function and acute rejection was 44% and 11% in the CsA group, and 40% and 8% in the SRL group. CMV infection incidence was low in both protocols. Three-year patient survival was 89% in the CsA and 76% in the SRL group. One- and 3-year graft survival after censoring for dead with a functioning allograft was 94.2% and 94% in CsA and 95% and 90% in SRL, respectively. Renal function was similar in both groups whereas proteinuria was higher in the SRL group. Uninephrectomy due to graft thrombosis or urinary-related complications was numerically higher in the SRL (21%) than in the CsA group (8%) (p = 0.13) and it was associated with renal failure and proteinuria. In DKT, a new induction immunosuppressive protocol based on rATG, SRL, MMF and prednisone does not offer any advantage in comparison to the old CsA, MMF and prednisone.     

Increased Risk of Thrombotic Microangiopathy in Patients Receiving a Cyclosporin–Sirolimus Combination

A single-center cohort study of kidney and kidney-pancreas recipients was conducted to evaluate the association between new immunosuppressive regimens and risk of thrombotic microangiopathy (TMA). From January 1st,1996 to December 31, 2002, 368 patients received a kidney or kidney-pancreas transplant at our center. Four immunosuppressive regimens were evaluated as potential risk factors of TMA: cyclosporin + mycophenolate mofetil (CsA + MMF), cyclosporin + sirolimus (CsA + SRL), tacrolimus + myophenolate mofetil (FK + MMF), and tacrolimus + sirolimus (FK + SRL). Thirteen patients developed biopsy-proven TMA in the absence of vascular rejection. The incidence of TMA was significantly different in the four immunosuppressive regimens studied (p < 0.001). The incidence of TMA was highest in the CsA + SRL group (20.7%). The relative risk of TMA was 16.1 [95% confidence interval (CI): 4.3-60.8] for patients in the CsA + SRL group as compared with those in the FK + MMF group. We also investigated in vitro the pathophysiological basis of this association. The CsA-SRL combination was found to be the only regimen that concomitantly displayed pro-necrotic and anti-angiogenic activities on arterial endothelial cells. We propose that this combination concurs to development of TMA through dual activities on endothelial cell death and repair.     

Efficacy on Renal Function of Early Conversion from Cyclosporine to Sirolimus 3 Months After Renal Transplantation: Concept Study

Sirolimus (SRL) allows to minimize the use of cyclosporine (CsA), but de novo administration after transplantation is associated with various complications. We report a prospective, open-label, multicenter randomized study to evaluate conversion from a CsA-based regimen to a SRL-based regimen 3 months after transplantation. One hundred ninety-two of a total of 237 patients were eligible at 3 months to be converted to SRL (n = 95) or to continue CsA (n = 97). All patients were also given mycophenolate mofetil (MMF) and oral steroids, planned to be discontinued at month 8. The primary endpoint, the clearance estimated according to Cockcroft and Gault at week 52, was significantly better in the SRL group (68.9 vs. 64.4 mL/min, p = 0.017). Patient and graft survival were not statistically different. The incidence of acute rejection episodes, mainly occurring after withdrawal of steroids, was numerically but not statistically higher in the SRL group (17% vs. 8%, p = 0.071). Sixteen patients discontinued SRL, mainly for adverse events (n = 11), and seven patients discontinued CsA for renal failure or acute rejection. Significantly, more patients in the SRL group reported aphthous, diarrhea, acne and high triglyceride levels. Conversion CsA to SRL 3 months after transplantation combined with MMF is associated with improvement in renal function.     

Two-year incidence of malignancy in sirolimus-treated renal transplant recipients: results from five multicenter studies

We examined the rates of malignancy at 2 yr after transplantation in renal allograft patients receiving sirolimus (SRL) in continuous combination with cyclosporine (CsA), SRL as base therapy or SRL maintenance therapy after early withdrawal of CsA. A total of 1295 patients were enrolled in two double-blind studies comparing SRL with azathioprine (AZA) or placebo administered in continuous regimens with CsA. In two other trials (n = 161), SRL given as base therapy was compared with CsA. In the fifth trial, patients were randomly assigned at 3 months to either remain on CsA + SRL therapy (n = 215) or to have CsA eliminated with SRL being continued in concentration-controlled doses (n = 215). At 2 yr after transplantation, patients receiving SRL in continuous combination with CsA had a significantly lower incidence of skin cancer compared with patients receiving placebo. Patients receiving SRL as base therapy had no malignancies compared with a 5% incidence in those receiving CsA. The incidence of malignancy was significantly lower in patients receiving concentration-controlled SRL with elimination of CsA compared with those who remained on CsA + SRL. Based on the currently available data, patients receiving SRL-based therapy without CsA or SRL maintenance therapy after early CsA withdrawal have lower rates of malignancy in the first 2 yr after renal transplantation. SRL immunotherapy may be beneficial in protecting renal transplant patients from skin cancer even when given in combination with CsA.     

Effect on kidney graft survival of reducing or discontinuing maintenance immunosuppression after the first year posttransplant

BACKGROUND: Data are scarce concerning the impact of maintenance immunosuppression dose reductions posttransplant. METHODS: Graft survival according to dose reduction or discontinuation of calcineurin inhibitors or mycophenolate mofetil (MMF) after the first year posttransplant was evaluated in 25,045 patients undergoing kidney transplantation during 1996 to 2005. No patient in this analysis had experienced a rejection and all had good graft function before dose reduction. RESULTS: Reduction of cyclosporine (CsA) dose to less than or equal to 150 mg/day, tacrolimus to less than or equal to 2 mg/day, or MMF to less than or equal to 1.0 g/day in patients on CsA or less than or equal to 0.5 g/day in patients on tacrolimus during the second year posttransplant was associated with a statistically significant reduction in graft survival (hazard ratios between 1.37 and 1.65). Withdrawal of CsA, tacrolimus, or MMF during year 2 was also associated with an increase in the risk of graft loss compared with continuing treatment (hazard ratio 1.52-1.73). CONCLUSIONS: This observational analysis indicates that in kidney transplant patients with good graft function, withdrawing maintenance CsA, tacrolimus or MMF, or reducing the dose of these agents below certain thresholds after the first year posttransplant is associated with a significant risk of graft loss.     

Long-term renal allograft function on a tacrolimus-based, pred-free maintenance immunosuppression comparing sirolimus vs. MMF.

It is not known how different steroid-free immunosuppressive combinations affect renal graft survival and long-term kidney transplant function. Here we sought to compare the impact on graft survival and long-term graft function of two tacrolimus (Tac)-based, prednisone-free maintenance immunosuppressive protocols: Tac/Mycophenolate Mofetil (MMF) vs. Tac/Sirolimus (SRL). Renal transplant patients given induction therapy with IL2-RA and methylprednisolone on days 0, 1 and 2 post-transplant were prospectively randomized to two maintenance immunosuppressive regimens with Tac/MMF (n = 45) or Tac/SRL (n = 37). During the 3-year follow-up the following data were collected: patient survival, renal allograft survival, incidence of acute rejection and glomerular filtration rate (GFR) at different time-points post-transplant. Cumulative graft survival was significantly different in the two groups: one kidney loss in the Tac/MMF vs. six kidney losses in the Tac/SRL (log-rank test p = 0.04). GFR at different time-points post-transplant was consistently and statistically better in the Tac/MMF than in the Tac/SRL group. The slope of GFR decline per month was flatter in the Tac/MMF than in the Tac/SRL group. This study showed that renal graft survival and graft function were significantly lower in the combination of Tac/SRL than Tac/MMF.     

Calcineurin-inhibitor-sparing immunosuppressive protocols

Calcineurin inhibitors (CNI) have played an important role in improving graft survival. However, the balance between preventing immunologic allograft losses and the management of CNI-related nephrotoxicity is still an issue in renal transplantation. There are three major CNI-sparing strategies. CNI MINIMIZATION: The advent of mycophenolate mofetil (MMF) allows cyclosporine (CsA) reduction to ameliorate renal function in patients with chronic renal allograft dysfunction, without increasing acute rejection rates. In combination with mTOR inhibitors, very low CNI levels may be sufficient to prevent acute rejection. However, in this association, CNI nephrotoxicity is magnified by pharmacokinetic interaction. CNI WITHDRAWAL: CNI withdrawal has been attempted in regimens containing MMF or sirolimus (SRL). Introduction of MMF in patients with chronic allograft nephropathy (CAN) followed by CNI withdrawal resulted in stabilization or improvement of renal function and hypertension profile, although there is some risk of acute rejection. In regimes based on SRL, CNI withdrawal is a safety strategy, achieving a sustained improvement of renal function, histology, and graft survival. There is not consensus at all whether MMF should be added or not in patients converted from CNI to mTOR inhibitor. CNI AVOIDANCE: Polyclonal-based regimens with MMF and steroids have shown acceptable acute rejection rates, but high rates of cytomegalovirus (CMV) and opportunistic infections. Conversely, anti-IL-2R in combination with MMF and steroids resulted in 50% incidence of acute rejection, thus suggesting that CNI avoidance is not feasible in a regimen based on MMF. Alternatively, a protocol based on anti-IL-2R induction therapy combined with SRL, MMF, and prednisone has shown an efficient prevention of acute rejection, higher creatinine clearance and lower rate of CAN in comparison with a group treated with CNI. New strategies using costimulation blockade may help in the development of safe CNI-free regimens. In summary, in renal transplantation the new immunosuppressive medications have made feasible old aspirations such as minimization, withdrawal, or even avoidance of CNI.     

Randomized trial of tacrolimus + mycophenolate mofetil or azathioprine versus cyclosporine + mycophenolate mofetil after cadaveric kidney transplantation: results at three years

METHODS: Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus (TAC) + mycophenolate mofetil (MMF), TAC + azathioprine (AZA), or cyclosporine (Neoral; CsA) + MMF. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function (DGF). Patients were followed-up for 3 years. RESULTS: The results at 3 years corroborate and extend the findings of the 2-year results. Patients with DGF treated with TAC+MMF experienced an increase in 3-year allograft survival compared with patients receiving CsA+MMF (84.1% vs. 49.9%, P=0.02). Patients randomized to either treatment arm containing TAC exhibited numerically superior kidney function when compared with CsA. During the 3 years, new-onset insulin dependence occurred in 6, 3, and 11 patients in the TAC+MMF, CsA+MMF, and TAC+AZA treatment arms, respectively. Furthermore, patients randomized to TAC+MMF received significantly lower doses of MMF as compared with those who received CsA+MMF. CONCLUSION: All three immunosuppressive regimens provided excellent safety and efficacy. However, the best results overall were achieved with TAC+MMF. The combination may provide particular benefit to kidney allograft recipients with DGF. In patients who experienced DGF, graft survival was better at 3 years in those patients receiving TAC in combination with either MMF or AZA as compared with the patients receiving CsA with MMF.     

Renal function after liver transplantation: calcineurin inhibitor nephrotoxicity

Renal failure, mainly due to calcineurin inhibitor (CNI) nephrotoxicity, is the most common complication following orthotopic liver transplantation (ltx). The aim of this study was to evaluate the incidence and course of renal failure in adult ltx patients. Severe acute renal failure in early postoperative period due to impaired hemodynamics and CNI nephrotoxicity, occurred in 14 patients, 3 of whom required dialysis. The creatinine clearance after ltx showed a tendency to decrease, but there was no statistically significant difference (P >.05) in the change in serum creatinine clearance levels between patients treated with tacrolimus (TAC) versus Cyclosporine (CsA) during the first 2 years of follow-up. Fourteen patients required conversion of their regimen because of CNI nephrotoxicity namely, dose reduction (n = 7) or discontinuation of CNI therapy with the replacement by mycophenolate mofetil (MMF) (n = 5) or SRL (n = 5). Dose reduction or CNI withdrawal significantly improved the creatinine clearance (P <.05) without affecting lives graft function. No episode of acute rejection was observed after conversion. Neither conversion of CsA to TAC nor the reverse maneuver significantly influenced the serum creatinine level (P >.05). Reduction of the CNI dose or CNI discontinuation or replacement with MMF or SRL in patients with stable liver but impaired renal function is safe, resulting in a significant improvement in renal function.     

Clinically Relevant Immunosuppressants Influence UVB-Induced Tumor Size Through Effects on Inflammation and Angiogenesis

Immunosuppressive therapies allow long-term patient and transplant survival, but are associated with increased development of UV-induced skin cancers, particularly squamous cell carcinomas. The mechanisms by which CsA, MMF, tacrolimus (TAC) or sirolimus (SRL), alone or in dual combinations, influence tumor development and progression are not completely understood. In the current study, chronically UV-exposed mice treated with SRL alone or in combination with CsA or TAC developed more tumors than mice treated with vehicle or other immunosuppressants, but the tumors were significantly smaller and less advanced. Mice treated with CsA or TAC developed significantly larger tumors than vehicle-treated mice, and a larger percentage in the CsA group were malignant. The addition of MMF to CsA, but not to TAC, significantly reduced tumor size. Immunosuppressant effects on UVB-induced inflammation and tumor angiogenesis may explain these findings. CsA enhanced both UVB-induced inflammation and tumor blood vessel density, while MMF reduced inflammation. Addition of MMF to CsA reduced tumor size and vascularity. SRL did not affect inflammation, but significantly reduced tumor vascularity. Thus the choice of immunosuppressants has important implications for tumor number, size and progression, likely due to the influence of immunosuppressants on UVB-induced inflammation and angiogenesis.     

Early conversion to a sirolimus-based, calcineurin-inhibitor-free immunosuppression in the SMART trial: observational results at 24 and 36months after transplantation

Early conversion to a calcineurin‐inhibitor (CNI)‐free maintenance immunosuppression with sirolimus (SRL), mycophenolate mofetil (MMF) and steroids was associated with an improved 1‐year renal function as compared with a cyclosporine (CsA)‐based regimen (SMART core‐study). This observational follow‐up describes 132 patients followed up within the SMART study framework for 36 months. At 36 months, renal function continued to be superior in SRL‐treated patients [ITT‐eGFR_@36m: 60.88 vs. 53.72 (CsA) ml/min/1.73 m², P = 0.031]. However, significantly more patients discontinued therapy in the SRL group 59.4% vs.42.3% (CsA). Patient [99% (SRL) vs.97% (CsA) and graft 96% (SRL) vs.94% (CsA)] survival at 36 months was excellent in both arms. There was no difference in late rejection episodes. Late infections and adverse events were similar in both arms except of a higher rate of hyperlipidemia in SRL and a higher incidence of malignancy in CsA‐treated patients. In a multivariate analysis, donor age >60 years, S‐creatinine at conversion >2 mg/dl, CMV naïve(‐) recipients and immunosuppression with CsA were predictive of an impaired renal function at 36 months. Early conversion to a CNI‐free SRL‐based immunosuppression is associated with a sustained improvement of renal function up to 36 months after transplantation. Patient selection will be key to derive long‐term benefit and avoid treatment failure using this mTOR‐inhibitor‐based immunosuppressive regimen.