Cyclosporine withdrawal improves renal function in heart transplant patients on reduced-dose cyclosporine therapy

Maintenance immunosuppression in heart transplantation: insights from network meta-analysis of various immunosuppression regimens

Previous studies have reported superiority of mechanistic target-of-rapamycin (mTOR) antagonists (mTA) over calcineurin inhibitors (CNI) as part of maintenance immunosuppression (IS) in mitigating cardiac allograft vasculopathy (CAV) after heart transplantation (HT). MEDLINE and EMBASE were searched through October 2019 for studies comparing maintenance IS with mTA + antimetabolites (AM), CNI + mTA or CNI + AM post HT. The main outcomes were all-cause mortality, CAV, acute rejection, CMV infections, and change in eGFR. To compare different IS antagonists, a random-effects network meta-analysis was performed. We used p-scores to rank best treatments per outcome. Our search identified fifteen eligible studies (5 studies comparing mTA + AM vs. CNI + AM, 9 comparing CNI + mTA vs. CNI + AM, 1 comparing mTA + AM vs. CNI + mTA, 8 using everolimus and 7 sirolimus as mTA) reporting the selected outcomes. We did not identify any statistical difference in all-cause mortality among the three IS regimens without heterogeneity among studies. CAV rates were significantly lower with CNI + mTA (odds ratio [OR] 0.53, 95% confidence interval [CI] 0.3-0.92). Acute rejection rates were significantly lower with CNI + AM (OR 0.26, 95% CI 0.12-0.56) and with CNI + mTA (OR 0.16, 95% CI 0.07-0.33) compared with mTA + AM without significant heterogeneity (I² = 43%, p = 0.9). CMV infections were significantly lower with mTA + AM (OR 0.13, 95% CI 0.03-0.46) and with CNI + mTA (OR 0.27, 95% CI 0.2-0.38) compared with CNI + AM without heterogeneity. mTA + AM led to higher eGFR compared with CNI + AM (9.06 ml/min/1.73 m2, 95% CI 3.15-14.97) and CNI + Mta (9.64 ml/min/1.73 m2, 95% CI 0.91-18.36), but the heterogeneity among studies was significant. CNI + mTA ranked better for CAV (p = 0.78), and acute rejection (p = 0.99) while mTA + AM for CMV infection (p = 0.94) and improvement in renal function (p = 0.93) than other regimens. Different IS regimens have similar effects on survival post HT, but CNI + mTA was associated with lower CAV rates, and acute rejection, while mTA + AM with less CMV infection post HT.

Sirolimus Adverse Event Profile in a Non-Clinical Trial Cohort of Heart Transplantation Patients

Background

Sirolimus has been used increasingly in heart transplantation for its ability to reduce acute rejection, prevent the progression of cardiac allograft vasculopathy (CAV), and preserve renal function. We sought to assess the adverse reactions associated with the use of sirolimus compared to mycophenolate mofetil (MMF).

Material/Methods

We retrospectively reviewed the charts of 221 adult heart transplant patients who received either sirolimus or MMF as part of their immunosuppression from June 1, 2001 to April 1, 2005. Patients were assigned to 2 groups based upon immunosuppression use. The prevalence and types of complications were recorded in each group.

Results

Sirolimus was received by 109 patients and 112 patients received MMF during the study period. Seventy-seven patients (71%) in the sirolimus group experienced adverse reactions compared to 45 patients (40%) in the MMF group (P<0.01). Compared to MMF, the use of sirolimus was associated with a higher prevalence of elevated triglyceride levels, lower-extremity edema, and oral ulcerations. Sirolimus was discontinued due to adverse reactions in 22% of patients, whereas no patients in the MMF group experienced adverse effects requiring drug discontinuation.

Conclusions

Compared to MMF, sirolimus use is associated with a higher prevalence of adverse reactions requiring drug discontinuation, but most patients were able to stay on therapy despite adverse effects.

Outcomes associated with mammalian target of rapamycin (mTOR) inhibitors in heart transplant recipients: A meta-analysis

BACKGROUND

Data evaluating mTOR inhibitor use heart transplant (HT) patients comes from relatively small studies and controversy exists regarding their specific role. We performed a meta-analysis of randomized trials to evaluate the efficacy and safety of mTOR inhibitors in HT patients.

METHODS

We performed a systematic literature search of Medline and Embase through July 2017 identifying studies evaluating mTOR inhibitors in HT patients reporting effects on coronary allograft vasculopathy (CAV), renal function, acute cellular rejection (ACR), cytomegalovirus (CMV) infection, and discontinuation due to adverse drug events (ADE). Data were pooled using a random-effects model producing a mean difference (MD; for continuous data) or odds ratio (OR; for dichotomous data) and 95% confidence interval (CI).

RESULTS

14 trials reported at least one outcome of interest. Change in mean maximal intimal thickness was significantly reduced with mTOR (-0.04 [-0.07 to -0.02]) compared to calcineurin inhibitor/mycophenolate mofetil (CNI/MMF). Rates of CMV infection were also significantly reduced (0.26; [0.2 to 0.32]) with mTOR regimens compared to CNI/MMF therapy. ACR was more frequent with CNI-sparing regimens 6.46 [1.55 to 26.95]). eGFR was significantly improved with CNI-sparing therapies (mean difference 12.09 mL/min [2.43 to 21.74]), but was similar between CNI/mTOR versus CNI/MMF regimens (p > 0.05). Rates of discontinuation due to ADE were higher in mTOR-containing regimens (OR 2.15 [1.28 to 3.60], p = 0.01), while mortality rates were similar (OR 0.91 [0.61 to 1.37], p = 0.62).

CONCLUSIONS

mTOR-containing regimens can attenuate CAV and CMV risk in HT recipients. A mTOR/MMF combination preserves renal function but increases the risk of ACR.

Calcineurin inhibitor- and corticosteroid-free immunosuppression in pediatric heart transplant patients

Pediatric heart transplant patients at our institution are immunosuppressed with a CNI and another immune-modulating agent without utilizing corticosteroids. Patients whose renal function worsened and who did not respond to CNI minimization had their CNI discontinued. The clinical history of 35 pediatric heart transplant patients with significant renal insufficiency whose CNI was discontinued was retrospectively analyzed. Data including serum creatinine and weight were collected before, at time of, and every 3-6 months after CNI discontinuation. This was used to calculate an eGFR. Cardiac allograft rejection and mortality data were also collected. CNI discontinuation occurred 39 times in 35 patients. The median eGFR significantly increased by 14 mL/min 3 months after CNI discontinuation and the increase continued to be significant (P≤.05) at 5 years. Freedom from rejection analysis showed no difference between graft rejection 2 years before versus after CNI discontinuation (P=.437). No mortality was associated with CNI discontinuation. Immunosuppression free of CNIs and corticosteroids appears to be a safe alternative in pediatric heart transplant patients with significant renal insufficiency. Furthermore, this strategy can significantly reverse renal insufficiency, even late after transplantation.

Acute Kidney Injury in Hematopoietic Stem Cell Transplantation: A Review

Hematopoietic stem cell transplantation (HSCT) is a highly effective treatment strategy for lymphoproliferative disorders and bone marrow failure states including aplastic anemia and thalassemia. However, its use has been limited by the increased treatment related complications, including acute kidney injury (AKI) with an incidence ranging from 20% to 73%. AKI after HSCT has been associated with an increased risk of mortality. The incidence of AKI reported in recipients of myeloablative allogeneic transplant is considerably higher in comparison to other subclasses mainly due to use of cyclosporine and development of graft-versus-host disease (GVHD) in allogeneic groups. Acute GVHD is by itself a major independent risk factor for the development of AKI in HSCT recipients. The other major risk factors are sepsis, nephrotoxic medications (amphotericin B, acyclovir, aminoglycosides, and cyclosporine), hepatic sinusoidal obstruction syndrome (SOS), thrombotic microangiopathy (TMA), marrow infusion toxicity, and tumor lysis syndrome. The mainstay of management of AKI in these patients is avoidance of risk factors contributing to AKI, including use of reduced intensity-conditioning regimen, close monitoring of nephrotoxic medications, and use of alternative antifungals for prophylaxis against infection. Also, early identification and effective management of sepsis, tumor lysis syndrome, marrow infusion toxicity, and hepatic SOS help in reducing the incidence of AKI in HSCT recipients.

Conversion From Calcineurin Inhibitors to Mammalian Target-of-Rapamycin Inhibitors in Heart Transplant Recipients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Conversion from calcineurin inhibitors (CNIs) to mammalian target-of-rapamycin inhibitors (mTORi) was systematically evaluated in heart transplant recipients (HTRs) for the first time.

METHODS

MEDLINE (PUBMED), EMBASE, Cochrane Library, and clinical trial registries were searched comprehensively. After screening for eligibility, the randomized controlled trials (RCTs) comparing continuation of CNI with conversion to mTORi therapy underwent review, quality assessment, and data extraction. Outcomes analyzed including creatinine clearance, serum creatinine level, rejection, adverse effects, and triglyceride levels were expressed as mean differences (MDs) or as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

This is the first systematic review evaluating converting from CNI to mTORi therapy in HTRs. A total of 4 RCTs (231 HTRs, 117 vs 114) were included in our analysis. Patients converted to mTORi had a higher creatinine clearance (MD, 19.31; 95% CI [11.16, 27.46]; P < .00001) and lower serum creatinine levels (MD, -0.15; 95% CI [-0.25, -0.05]; P = .002). Patients converted to mTORi had a significantly higher occurrence of adverse effects, which included skin diseases, gastrointestinal side effects, bone marrow suppression, and infections. There was no significant difference between the 2 groups regarding graft rejection and triglyceride levels (RR, 2.61; 95% CI [0.08, 81.25]; P = .58; MD, 22.89; 95% CI [-21.86, 67.63]; P = .32).

CONCLUSIONS

Conversion from CNI to mTORi therapy may improve the renal function in HTRs, but the patients may suffer from a high incidence of mTORi-associated adverse events. Therefore, conversion to mTORi must be carefully assessed for the benefits and risks.

Chronic renal insufficiency in heart transplant recipients: risk factors and management options

Renal dysfunction after heart transplantation is a frequently observed complication, in some cases resulting in significant limitation of quality of life and reduced survival. Since the pathophysiology of renal failure (RF) is multifactorial, the current etiologic paradigm for chronic kidney disease after heart transplantation relies on the concept of calcineurin inhibitor (CNI)-related nephrotoxicity acting on a predisposed recipient. Until recently, the management of RF has been restricted to the minimization of CNI dosage and general avoidance of classic nephrotoxic risk factors, with somewhat limited success. The recent introduction of proliferation signal inhibitors (PSIs) (sirolimus and everolimus), a new class of immunosuppressive drugs lacking intrinsic nephrotoxicity, has provided a completely new alternative in this clinical setting. As clinical experience with these new drugs increases, new renal-sparing strategies are becoming available. PSIs can be used in combination with reduced doses of CNIs and even in complete CNI-free protocols. Different strategies have been devised, including de novo use to avoid acute renal toxicity in high-risk patients immediately after transplantation, or more delayed introduction in those patients developing chronic RF after prolonged CNI exposure. In this review, the main information on the clinical relevance and pathophysiology of RF after heart transplantation, as well as the currently available experience with renal-sparing immunosuppressive regimens, particularly focused on the use of PSIs, is reviewed and summarized, including the key practical points for their appropriate clinical usage.

Advantageous effects of immunosuppression with tacrolimus in comparison with cyclosporine A regarding renal function in patients after heart transplantation

BACKGROUND

Nephrotoxicity is a serious adverse effect of calcineurin inhibitor therapy in patients after heart transplantation (HTX).

AIM

In this retrospective registry study, renal function within the first 2 years after HTX in patients receiving de novo calcineurin inhibitor treatment, that is, cyclosporine A (CSA) or tacrolimus (TAC), was analyzed. In a consecutive subgroup analysis, renal function in patients receiving conventional tacrolimus (CTAC) was compared with that of patients receiving extended-release tacrolimus (ETAC).

METHODS

Data from 150 HTX patients at Heidelberg Heart Transplantation Center were retrospectively analyzed. All patients were continuously receiving the primarily applied calcineurin inhibitor during the first 2 years after HTX and received follow-up care according to center practice.

RESULTS

Within the first 2 years after HTX, serum creatinine increased significantly in patients receiving CSA (P<0.0001), whereas in patients receiving TAC, change of serum creatinine was not statistically significant (P=not statistically significant [ns]). McNemar's test detected a significant accumulation of patients with deterioration of renal function in the first half year after HTX among patients receiving CSA (P=0.0004). In patients receiving TAC, no significant accumulation of patients with deterioration of renal function during the first 2 years after HTX was detectable (all P=ns). Direct comparison of patients receiving CTAC versus those receiving ETAC detected no significant differences regarding renal function between patients primarily receiving CTAC or ETAC treatment during study period (all P=ns).

CONCLUSION

CSA is associated with a more pronounced deterioration of renal function, especially in the first 6 months after HTX, in comparison with patients receiving TAC as baseline immunosuppressive therapy.

Impact of the reduction of calcineurin inhibitors on renal function in heart transplant patients: a systematic review and meta-analysis

AIMS

Calcineurin inhibitors (CNIs) taken after heart transplantation lead to excellent short-term outcomes, but long-term use may cause chronic nephrotoxicity. Our aim was to identify, appraise, select and analyse all high-quality research evidence relevant to the question of the clinical impact of CNI-sparing strategies in heart transplant patients.

METHODS

We carried out a systematic review and meta-analysis of randomized controlled trials on CNI reduction in heart transplant recipients. Primary outcomes were kidney function and acute rejection after 1 year. Secondary outcomes included graft loss, all-cause mortality and adverse events.

RESULTS

Eight open-label studies were included, with 723 patients (four tested de novo CNI reduction and four maintenance CNI reduction). Calcineurin inhibitor reduction did not improve creatinine clearance at 12 months 5.46 [-1.17, 12.03] P = 0.32 I(2)  = 65.4%. Acute rejection at 12 months (55/360 vs. 52/332), mortality (18/301 vs. 15/270) and adverse event rates (55/294 vs. 52/281) did not differ between the low-CNI and standard-CNI groups. There was significant benefit on creatinine clearance in patients with impaired renal function at 6 months [+12.23 (+5.26, +18.82) ml min(-1) , P = 0.0003] and at 12 months 4.63 [-4.55, 13.82] P = 0.32 I(2)  = 75%.

CONCLUSIONS

This meta-analysis did not demonstrate a favourable effect of CNI reduction on kidney function, but there was no increase in acute rejection. To provide a better analysis of the influence of CNI reduction patterns and associated treatments, a meta-analysis of individual patient data should be performed.

Use of mTOR inhibitors in chronic heart transplant recipients with renal failure: calcineurin-inhibitors conversion or minimization?

BACKGROUND

In the last decade, mTOR inhibitors (mTOR-is) have become the cornerstone of the calcineurin inhibitor (CNI)-reduced/free regimens aimed to the preservation of post-transplant renal function. We compared utility and safety of the total replacement of calcineurin inhibitors with a mTOR-i with a strategy based on calcineurin inhibitor minimization and concomitant use of m-TOR-i.

METHODS

In a retrospective multi-center cohort of 394 maintenance cardiac recipients with renal failure (GFR<60 mL/min/1.73 m(2)), we compared 235 patients in whom CNI was replaced with a mTOR-i (sirolimus or everolimus) with 159 patients in whom mTOR-is were used to minimize CNIs. A propensity score analysis was carried out to balance between group differences.

RESULTS

Overall, after a median time of 2 years from mTOR-i initiation, between group differences for the evolution of renal function were not observed. In a multivariate adjusted model, improvement of renal function was limited to patients with mTOR-i usage within 5years after transplantation, particularly with the conversion strategy, and in those patients who could maintain mTOR-i therapy. Significant differences between strategies were not found for mortality, infection and mTOR-i withdrawal due to drug-related adverse events. However, conversion group tended to have a higher acute rejection incidence than the minimization group (p=0.07).

CONCLUSION

In terms of renal benefits, our results support an earlier use of mTOR-is, irrespective of the strategy. The selection of either a conversion or a CNI minimization protocol should be based on the clinical characteristics of the patients, particularly their rejection risk.

Rejection after conversion to a proliferation signal inhibitor in chronic heart transplantation

We sought to determine the incidence, risk factors, and consequences of acute rejection (AR) after conversion from a calcineurin inhibitor (CNI) to a proliferation signal inhibitor (PSI) in maintenance heart transplantation. Relevant clinical data were retrospectively obtained for 284 long-term heart transplant recipients from nine centers in whom CNIs were replaced with a PSI (sirolimus or everolimus) between October 2001 and March 2009. The rejection rate at one yr was 8.3%, stabilizing to 2% per year thereafter. The incidence rate after conversion (4.9 per 100 patient-years) was significantly higher than that observed on CNI therapy in the pre-conversion period (2.2 per 100 patient-years). By multivariate analysis, rejection risk was associated with a history of late AR prior to PSI conversion, early conversion (<5 yr) after transplantation and age <50 yr at the time of conversion. Use of mycophenolate mofetil was a protective factor. Post-conversion rejection did not significantly influence the evolution of left ventricular ejection fraction, renal function, or mortality during further follow-up. Conversion to a CNI-free immunosuppression based on a PSI results in an increased risk of AR. Awareness of the clinical determinants of post-conversion rejection could help to refine the current PSI conversion strategies.

Calcineurin inhibitor-free immunosuppression using everolimus (Certican) after heart transplantation: 2 years' follow-up from the University Hospital Münster

BACKGROUND

Everolimus is a proliferation-signal inhibitor which was introduced for heart transplant recipients in 2004. To date, there are only sparse data about long-term calcineurin inhibitor (CNI)-free immunosuppression using everolimus.

METHODS

After heart transplantation, patients receiving everolimus were consecutively enrolled. Reasons for switching to everolimus were side effects of CNI immunosuppression, such as deterioration of kidney function and recurrent rejection episodes. All 60 patients underwent standardized switching protocols, 42 patients completed 24-month follow-up. Blood was sampled for lipid status, renal function, routine controls, and levels of immunosuppressive agents. On days 0, 14, and 28, and then every 3 months, echocardiography and physical examination were performed.

RESULTS

After switching to everolimus, most patients recovered from the side effects. Renal function improved significantly after 24 months (creatinine, 2.1 ± 0.6 vs 1.8 ± 1 mg/dL; P < .001; creatinine clearance, 41.8 ± 22 vs 48.6 ± 21.8 mL/min; P < .001). Median blood pressure increased from 120.0/75.0 mm Hg at baseline to 123.8/80.0 mm Hg at month 24 (P values .008 and .003 for systolic and diastolic pressures, respectively). Tremor, peripheral edema, hirsutism, and gingival hyperplasia markedly improved. Levels of interleukin-6 were stable between baseline and 24-month levels. Temporary adverse events occurred in 8 patients [13.3%: interstitial pneumonia (n = 2), skin disorders (n = 2); reactivated hepatitis B (n = 1), and fever of unknown origin (n = 3)].

CONCLUSION

CNI-free immunosuppression using everolimus is safe, with excellent efficacy in maintenance of heart transplant recipients. Arterial hypertension and renal function significantly improved. CNI-induced side effects, such as tremor, peripheral edema, hirsutism, and gingival hyperplasia, markedly improved in most patients.

Prospective study of everolimus with calcineurin inhibitor-free immunosuppression in maintenance heart transplant patients: results at 2 years

BACKGROUND

Few studies have examined everolimus therapy with calcineurin inhibitor (CNI) withdrawal in maintenance heart transplant patients.

METHODS

In a prospective, single-arm, single-center study, CNI-treated heart transplant patients were converted to everolimus and were followed up for 24 months. The primary endpoints were kidney function and arterial hypertension at 12 and 24 months after conversion.

RESULTS

Fifty-eight patients were recruited (mean time posttransplant 5.6±3.7 years), 55 of whom (91.7%) had renal impairment. Mean creatinine clearance increased from 43.6±21.1 mL/min to 49.5±21.2 mL/min at month 24 (P=0.02). Median blood pressure increased from 120/80 mm Hg at baseline to 122.5/80 mm Hg (P=0.008 and 0.006 for systolic and diastolic pressure, respectively). Lipid parameters did not change significantly over the 24-month follow-up. Early resolution of most non-renal CNI-related adverse events was sustained. CNI therapy was re-introduced at a mean of 309 days (range, 31-684 days) in eight patients after month 6 due to adverse events (n=13) or withdrawal of consent (n=2). No significant changes in cardiac function parameters were observed.

CONCLUSIONS

CNI-free immunosuppression with everolimus is an effective and safe option in selected heart transplant maintenance patients. Most adverse effects under everolimus occurred early after conversion and generally resolved without intervention within a few weeks. Refining selection criteria may reduce the need to re-introduce CNI therapy.

Mycophenolate monitoring in liver, thoracic, pancreas, and small bowel transplantation: a consensus report

Assessing the value of mycophenolic acid (MPA) monitoring outside renal transplantation is hindered by the absence of any trial comparing fixed-dose and concentration-controlled therapy. However, in liver and thoracic transplantation particularly, clinical trials, observational studies with comparison groups, and case series have described MPA efficacy, exposure/efficacy relationships, pharmacokinetic variability, and clinical outcomes relating to plasma MPA concentrations. On the basis of this evidence, this report identifies MPA as an immunosuppressant for which the combination of variable disposition, efficacy, and adverse effects contributes to interindividual differences seemingly in excess of those optimal for a fixed-dosage mycophenolate regimen. Combined with experiences of MPA monitoring in other transplant indications, the data have been rationalized to define circumstances in which measurement of MPA concentrations can contribute to improved management of mycophenolate therapy in nonrenal transplant recipients.

Clinical recommendations for the use of everolimus in heart transplantation

Proliferation signal inhibitors (PSIs), everolimus (EVL), and sirolimus are a group of immunosuppressor agents indicated for the prevention of acute rejection in adult heart transplant recipients. Proliferation signal inhibitors have a mechanism of action with both immunosuppressive and antiproliferative effects, representing an especially interesting treatment option for the prevention and management of some specific conditions in heart transplant population, such as graft vasculopathy or malignancies. Proliferation signal inhibitors have been observed to work synergistically with calcineurin inhibitors (CNIs). Data from clinical trials and from the growing clinical experience show that when administered concomitantly with CNIs, PSIs allow significant dose reductions of the latter without loss of efficacy, a fact that has been associated with stabilization or significant improvement in renal function in patients with CNI-induced nephrotoxicity. The purpose of this article was to review the current knowledge of the role of PSIs in heart transplantation to provide recommendations for the proper use of EVL in cardiac transplant recipients, including indications, treatment regimens, monitoring, and management of the adverse events.

Usefulness of sirolimus as rescue therapy in heart transplant recipients with renal failure: analysis of the Spanish Multicenter Observational Study (RAPACOR)

BACKGROUND

Chronic renal failure is a common complication of heart transplantation. Sirolimus (SRL) is an immunosuppressive drug that, unlike calcineurin inhibitors (CNIs), is not associated with nephrotoxicity.

METHODS

We collected efficacy and safety data from a Spanish registry of heart transplant recipients who were switched from a CNI to SRL due to renal failure. Patients were included if the serum creatinine level before switching was >1.5 mg/dL and/or the estimated creatinine clearance level was below 50 mL/min.

RESULTS

Ninety-seven patients started SRL due to renal impairment. When SRL was started, CNIs were progressively tapered and in some cases withdrawn. Mean baseline creatinine level was 2.5 mg/dL and mean creatinine clearance level was 39 mL/min. Only 1 episode of acute rejection was observed in a patient receiving SRL plus cyclosporine (CsA) but the eventual allograft function remained stable. Compared with baseline, a significant improvement in renal function was observed at 6 months among patients who stopped CNIs before the third month after SRL was started, although not among those who continued taking CNIs. Upon multivariate analysis, no predictors of response were observed. SRL was withdrawn in 18% of patients due to adverse events.

CONCLUSIONS

Switching to SRL was safe in heart allograft recipients, improving renal function among those previously receiving a CNI. Renal function improves if CNIs are withdrawn soon after starting SRL.

Reduction of cyclosporine following the introduction of everolimus in maintenance heart transplant recipients: a pilot study

Data are scarce concerning the calcineurin inhibitor dose reduction required following introduction of everolimus in maintenance heart transplant recipients to maintain stable renal function. In a 48-week, multicenter, single-arm pilot study in heart transplant patients >12 months post-transplant, everolimus was started at 1.5 mg/day (subsequently adjusted to target C(0) 5-10 ng/ml). Mycophenolate mofetil or azathioprine was discontinued on the same day and cyclosporine (CsA) dose was reduced by 25%, with a further 25% reduction each time calculated glomerular filtration rate (cGFR) decreased to <75% of baseline. Of 36 patients enrolled, 25 were receiving everolimus at week 48. From baseline to week 48, there was a mean decrease of 44.5%, 50.9% and 44.6% in CsA dose, C(0) and C(2), respectively. Mean cGFR was 68.9 +/- 14.5 ml/min at baseline and 61.6 +/- 11.5 ml/min at week 48 (P = 0.018). The prespecified criterion for stable renal function was met, i.e. a mean decrease <or=25% of cGFR from baseline. Two patients experienced biopsy-proven acute rejection Grade 3A (5.6%). Between baseline and week 48, there were significant increases in total cholesterol, LDL cholesterol and triglycerides, and small but significant elevations in liver enzymes. This 1-year pilot study suggests that CsA dose reduction of ca. 40% after initiation of everolimus was associated with a decrease in cGFR, however, based on the prespecified criteria stable renal function was attained.

Long-term immunosuppression with anti-CD25 monoclonal antibodies in heart transplant patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD), a frequent and serious complication after heart transplantation, is associated with increased mortality. Current strategies include dose reduction or conversion from calcineurin inhibitors (CNIs) to either mycophenolate mofetil and/or rapamycin, with variable results and side-effect profiles.

METHODS

We evaluated the effectiveness of long-term anti-CD25 monoclonal antibody (MAb)-based immunosuppression in 17 adult heart transplant recipients with CKD at 10 +/- 5 years post-transplant. Seven patients had previously been switched to rapamycin but had untreatable side-effects and 10 patients were still on a CNI. The latter were matched with 10 control heart transplant patients whose renal function had remained stable over a similar post-transplant follow-up period, on CNI.

RESULTS

Anti-CD25 MAb were given over 13 +/- 10 months and were well tolerated with CD25 saturation monitoring (target <2% expression). Side-effects secondary to rapamycin resolved in 6 patients. The slope change of the creatinine clearance improved in patients in whom CNIs were discontinued (+0.335 ml/min/month vs -0.124 ml/min/month in controls, p = 0.03). Four patients died. Three died after 2, 6 and 7 months of follow-up, respectively, with the following diagnoses: acute renal failure (the patient refused dialysis); acute rejection (the patient had refused protocol endomyocardial biopsy); and perforated diverticulitis. The fourth patient died of pneumonia, 3 months after conversion from anti-CD25 MAb to rapamycin, because of poor venous access.

CONCLUSIONS

The use of long-term anti-CD25 MAb therapy as a potential replacement for CNI- and rapamycin-based immunosuppression is feasible. It is crucial that rejection surveillance be intensified. A randomized, controlled trial is required to confirm the benefits and safety of this strategy.

Mycophenolate and sirolimus as calcineurin inhibitor-free immunosuppression improves renal function better than calcineurin inhibitor-reduction in late cardiac transplant recipients with chronic renal failure

BACKGROUND

Calcineurin-inhibitor-(CNI)-induced renal failure is one major cause of morbidity in cardiac transplantation (HTx). In this prospective, randomized, multicenter trial, the impact of immunosuppressive conversion toward CNI-free (mycophenolate mofetil [MMF] and sirolimus) or a CNI-reduced immunosuppressive regimen on renal function, efficacy, and safety was evaluated.

METHODS

Since 2004, 63 HTx-patients (0.5-18.4 years after HTx) with CNI-based immunosuppression and reduced creatinine clearance less than 60 mL/min (39+/-15 mL/min) were included in this trial. Patients in the CNI-free-Group (group 1) were converted to sirolimus that was started with 2 mg/day until target trough levels (8-14 ng/mL) were achieved. Subsequently, CNIs were withdrawn. In CNI-reduction-Group (group 2), CNI target trough levels were reduced by 40%. In both groups MMF was continued and trough level adjusted (1.5-4 microg/mL).

RESULTS

Patients demographics and survival (mean follow-up time: 16.7+/-9 months) was equal (100%). Renal function improved significantly after complete CNI withdrawal while remaining unchanged with CNI-reduction (Creatinine clearance after 12 months: 53+/-24 mg/dL [group 1] vs. 38+/-20 mg/dL [group 2], P=0.01). End-stage renal failure (hemodialysis) was avoided by CNI-withdrawal and occurred only after CNI reduction (n=6; P=0.01). Acute rejection episodes were more common in group 2 (4 vs. 2). Graft function remained stable (echocardiography) within both groups. Adverse events were more common in group 1 (65%) than in group 2 (n=40%) and were responsible for discontinuation in 4 and 0 cases, respectively.

CONCLUSIONS

Conversion toward a CNI-free immunosuppression (Mycophenolate, sirolimus) is superior to CNI-reduced immunosuppression in improving renal failure in late HTx-recipients. However, this benefit is relativized by the increased incidence and severity of sirolimus/MMF-associated side effects.

The clinical impact of an early decline in kidney function in patients following heart transplantation

Renal dysfunction is a well-known complication following heart transplantation. We examined an early decline in kidney function as a predictor of progression to end-stage renal disease and mortality in heart transplant recipients. We performed a retrospective cohort study of 233 patients who received a heart transplant between July 1985 and July 2004, and who survived >1 month. The decline in estimated creatinine clearance (CrCl) was used to predict the outcomes of need for chronic dialysis or mortality >1-year posttransplant. The earliest time to chronic dialysis was 484 days. A 30% decline in CrCl between 1 month and 12 months predicted the need for chronic dialysis (p = 0.01), all-cause mortality (p < 0.0001) and time to first CrCl </=30 mL/min at >1-year posttransplant (p = 0.02). A 30% decline in CrCl between 1 month and 3 months also independently predicted the need for chronic dialysis (p = 0.04) and time to first CrCl </= 30 mL/min at >1-year posttransplant (p = 0.01). In conclusion, an early drop in CrCl within the first year is a strong predictor of chronic dialysis and death >1-year postheart transplantation. Future studies should focus on kidney function preservation in those identified at high risk for progression to end-stage kidney disease and mortality.

Development of proteinuria after switch to sirolimus-based immunosuppression in long-term cardiac transplant patients

Calcineurin-inhibitor therapy can lead to renal dysfunction in heart transplantation patients. The novel immunosuppressive (IS) drug sirolmus (Srl) lacks nephrotoxic effects; however, proteinuria associated with Srl has been reported following renal transplantation. In cardiac transplantation, the incidence of proteinuria associated with Srl is unknown. In this study, long-term cardiac transplant patients were switched from cyclosporine to Srl-based IS. Concomitant IS consisted of mycophenolate mofetil +/- steroids. Proteinuria increased significantly from a median of 0.13 g/day (range 0-5.7) preswitch to 0.23 g/day (0-9.88) at 24 months postswitch (p = 0.0024). Before the switch, 11.5% of patients had high-grade proteinuria (>1.0 g/day); this increased to 22.9% postswitch (p = 0.006). ACE inhibitor and angiotensin-releasing blocker (ARB) therapy reduced proteinuria development. Patients without proteinuria had increased renal function (median 42.5 vs. 64.1, p = 0.25), whereas patients who developed high-grade proteinuria showed decreased renal function at the end of follow-up (median 39.6 vs. 29.2, p = 0.125). Thus, proteinuria may develop in cardiac transplant patients after switch to Srl, which may have an adverse effect on renal function in these patients. Srl should be used with ACEi/ARB therapy and patients monitored for proteinuria and increased renal dysfunction.

Possible Role of Everolimus in Improving Renal Function in Long-Term Heart Transplantation

Patient survival after heart transplantation has improved dramatically since the availability of calcineurine inhibitor (CNIs); the number of long-term patients is progressively increasing. However, in these patients, nephrotoxicity of CNIs has been largely responsible for the progressive development of renal dysfunction. Since impaired renal function is an important issue that reduces long-term patient survival, it is important to develop strategies to improve renal function while maintaining immunologic safety to preserve graft function. Everolimus is an mTOR inhibitor sirolimus analogue, that has proved, to be highly efficacious to prevent acute myocardial rejection and reduce the severity of cardiac allograft vasculopathy in de novo HTx patients. There is reasonable evidence that, in long term heart transplanted patients, renal function may improve when everolimus is administered associated with a progressive reduction of CNIs. So far there is no evidence to identify which patient may benefit from this therapeutic approach. Indeed everolimus alone may be equally effective to prevent rejection and improve renal function when CNIs are completely discontinued, but data are still lacking on the risks, dosages and side effects of this type of immunosuppression. Ongoing clinical studies will provide further guidance about the possibility to halt or reduce the progression of renal impairment in long term heart transplant patients.