Cyclosporin A withdrawal in live related renal transplantation: long-term results

Randomized study comparing cyclosporine with azathioprine one year after renal transplantation-15-year outcome data

BACKGROUND

The introduction of cyclosporine (CsA) improved 1-year graft survival and reduced the incidence of acute rejection episodes after renal transplantation compared to azathioprine (Aza). However, CsA has many side effects and reducing exposure of this drug after the first year may benefit long-term patient and graft survival.

METHODS

We report 15-year outcome data from a single center, randomized controlled study comparing CsA withdrawal and conversion to Aza with continuation of CsA 1-year posttransplant.

RESULTS

Two hundred sixteen patients who showed a serum creatinine less than 300 mumol/L with no acute rejection episodes in the preceding 6 months were enrolled (CsA 114, Aza 102). There was no difference in patient survival at 15 years: 62.4% in the CsA group and 64.4% in the Aza group (P=0.6). Fifteen-year transplant survival was 41.9% for the CsA group and 48.8% for the Aza group (P=0.8). Fifteen-year graft survival censoring for death with a functioning graft was 58% in the CsA group and 72% in the Aza group (P=0.5). Predictors of patient survival were younger recipient age (P<0.001) and lower systolic blood pressure at randomization (P=0.01). Predictors of graft survival were older recipient age (P<0.001) and better renal function at randomization (P=0.01). Assigned drug showed no effect on graft or patient survival. Patients assigned to CsA showed significantly worse renal function up to 10 years posttransplantation and required more anti-hypertensive treatment throughout the study period.

CONCLUSION

In a selected group of patients, either Aza or low-dose CsA is safe and effective. Despite lower estimated glomerular filtration rate (eGFR) up to 10 years posttransplantation and increased use of anti-hypertensive agents, low-dose CsA was not associated with a worse patient or graft survival.

Benefit-Risk Assessment of Ciclosporin Withdrawal in Renal Transplant Recipients

Ciclosporin is associated with significant toxicity, including nephrotoxicity, and with an increased risk of cardiovascular events. Many attempts have been made to wean patients from ciclosporin. Before the availability of new immunosuppressive drugs, the acute rejection rate observed after ciclosporin withdrawal did not permit the widespread use of withdrawal regimens even though meta-analysis did not show that they adversely affected patient or graft survival. Nevertheless, maintenance therapy with azathioprine and corticosteroids has not become routine practice. The introduction of mycophenolate mofetil and subsequently sirolimus has increased the number of clinical studies of the effects of ciclosporin withdrawal. In stable patients, this withdrawal is associated with a small but significant increase in the incidence of acute rejection episodes. Declining renal function and other forms of ciclosporin-related toxicity have improved. However, this improvement was also observed when ciclosporin was only reduced (and not withdrawn), which did not increase the risk of acute rejection. More precise definition of the patients who could benefit from ciclosporin-withdrawal may help to optimise the immunosuppressive regimen in this setting. In patients with chronic allograft deterioration, ciclosporin withdrawal together with mycophenolate mofetil introduction has been shown to improve renal function significantly in many small studies, and a large prospective randomised study. For the time being, ciclosporin withdrawal is a good therapeutic option for patients with declining renal function and signs of chronic ciclosporin nephrotoxicity on renal biopsy. Finally, recent preliminary studies have reported the results of complete avoidance of calcineurin inhibitors after renal transplantation. These results are promising as regards the incidence of acute rejection, renal function and safety, but need confirmation in larger trials with a longer follow-up. Nevertheless, it has become clear that the concept of an immunosuppressive regimen with little or no nephrotoxicity after renal transplantation is more and more important and plays a crucial part in tailoring immunosuppression to the needs of specific patient populations.

Outcome of pediatric renal transplants in a developing country

This study was conducted to evaluate the outcome of pediatric renal transplants at our center. A retrospective analysis was done on 39 pediatric transplants (age at transplant <18 years) done at our center over the last 10 years. The mean age at transplant was 15.6+/-1 years (10-17 years). They comprised 4.2% of all renal transplants done at our center (39/921) over the period. Girls comprised 17.5% of total recipients ( n=7). Two patients had a preemptive transplant. The underlying causes of end stage renal disease were chronic glomerulonephritis ( n=21), chronic interstitial nephritis ( n=17) and Alport syndrome [1]. All the 39 children were initiated on triple drug immunosuppression (cyclosporin A (CsA) azathioprine, prednisolone). All patients received grafts from living related donors. In the first month, three patients had graft loss (serum creatinine, SCr, >5 mg/dl). Of these, two patients died because of septicemia and one had acute cortical necrosis. There was evidence of infection in 16 patients (40%). Acute rejection was seen in 17 patients (45.8%). The 1-year patient and graft survival was 89% and at 3 years 70%. The actuarial graft survival at 5 years was 50%. Twelve children discontinued CsA after 1 year post-transplant and five of these had graft loss. Graft losses were significantly greater in patients who discontinued CsA as compared to those who continued CsA (5/12 vs 2/22). After a mean follow-up of 31.5+/-3.5 months, of the 37 patients, 10 had graft loss and chronic graft dysfunction was observed in another 9 patients. The rest of the 17 (48%) patients had a mean SCr of 1.2 mg/dl. The long-term outcome of pediatric renal transplants in our country remains suboptimal. CsA discontinuation due to financial constraints and/or non-compliance remain the most important reasons for this.

New developments in immunosuppressive therapy in renal transplantation

The introduction of new immunosuppressive agents and protocols has improved outcomes for renal transplant recipients by decreasing the risk of rejection and by increasing the function and lifespan of the allograft. This article reviews the major changes in the combinations of therapies used: calcineurin inhibitors, target of rapamycin inhibitors, mycophenolate mofetil, non-depleting monoclonal versus depleting monoclonal and polyclonal antibodies for induction and increasing emphasis on protocols for reduction or avoidance of steroids and calcineurin inhibitors. The new agents with novel immunological targets such as anti-CD40 ligand, LEA29Y, FTY720, anti-CD20 (rituximab, Rituxan, Mabthera) and anti-CH52 (alemtuzumab, Campath), which are under development but have yet to survive the rigors of clinical trials are also discussed. In the presence of low early rejection rates, immunosuppressive therapy is setting new goals such as better graft function (glomerular filtration rates), reduction in adverse effects such as hypertension, hyperlipidaemia and drug toxicity and, above all, the prevention of late graft deterioration.

Early clinical experience with a novel rapamycin derivative

SDZ RAD (everolimus, Certican is a novel macrolide immunosuppressant that blocks growth factor-driven transduction signals in the T-cell response to alloantigen. After stimulation of the IL-2 receptor on the activated T-cell, SDZ RAD inhibits p70S6 kinase, acting at a later stage in the T-cell mediated response than do cyclosporine and other calcineurin inhibitors (CNIs). Unlike the CNIs, SDZ RAD is a proliferation signal inhibitor, blocking growth factor-driven proliferation of both hematopoietic and nonhematopoietic cells. These activities are complementary to those of cyclosporine and provide a rationale for the addition of SDZ RAD to cyclosporine-based immunosuppression, with the potential for minimizing CNI nephrotoxicity, reducing the incidence of acute rejection, and favoring long-term graft survival. Potential also exists for beneficial effects on other factors that may influence the development of chronic rejection. These factors include comorbid diseases such as hypertension, which may affect transplant vasculopathy, and opportunistic infection with cytomegalovirus (CMV) and other viruses, which may increase the risk of chronic rejection. The synergistic effect of SDZ RAD and cyclosporine has been confirmed in preclinical models, with graft survival being significantly prolonged in rat models of kidney and heart allotransplantation. Clinical experience with SDZ RAD in cyclosporine-based immunosuppression, including low-dose cyclosporine regimens, has also resulted in predictable and favorable clinical outcomes. Low rates of acute rejection, excellent rates of patient and graft survival, lower incidence of CMV infections, better cholesterol, triglyceride and creatinine profiles, and better renal function have been demonstrated with SDZ RAD and lower doses of cyclosporine (Neoral; Novartis) in recipients of renal transplants. These findings, combined with good tolerability rates and an acceptable side-effect profile, indicate that the synergistic profile of SDZ RAD in combination with nontoxic dosages of CNI's and IL2 inhibitors will further improve longterm results in renal transplantation.

Progress in the clinical application of immunosuppressive drugs in renal transplantation

Although only very few new immunosuppressive drugs have been approved over the past two decades, the introduction of each new drug has progressively reduced the incidence of acute rejection and raised hopes that there would be an increase in long-term allograft survival. It is now consistently possible to achieve acute rejection rates of between 10 and 20%, and in many studies the rate has fallen below 10%. This is important, as acute rejection is one of the most important factors reducing the long-term survival of the allograft as a consequence of the development of chronic allograft nephropathy. The availability of these new agents has allowed experimentation with diverse protocols that explore the possibility of reduced exposure to calcineurin inhibitors and corticosteroids. These include both 'avoidance' and 'withdrawal' protocols. The target of rapamycin inhibitors, sirolimus and everolimus, have extended this paradigm. It is possible, but not yet proved, that their antiproliferative effect on smooth muscle will retard the vascular remodelling characteristic of chronic allograft nephropathy, atherosclerosis and hypertension. This review concentrates on the current progress being made in clinical immunosuppression, and includes data presented at the Transplant 2001 meeting of the American Society of Transplantation and the American Society of Transplant Surgeons, held in May 2001.