Elective cyclosporine withdrawal 1 year after renal transplantation

Management of post-transplant lymphoproliferative disorder in adult solid organ transplant recipients - BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder in adult recipients of solid organ transplants. This review details the therapeutic options recommended including reduction in immunosuppression (RIS), transplant organ resection, radiotherapy and chemotherapy. Effective therapy should be instituted before progressive disease results in declining performance status and multi-organ dysfunction. The goal of treatment should be a durable complete remission with retention of transplanted organ function with minimal toxicity.

Minimization of calcineurin inhibitors to improve long-term outcomes in kidney transplantation

Long-term outcomes after kidney transplantation remain suboptimal, despite the great achievements observed in recent years with the use of modern immunosuppressive drugs. Currently, the calcineurin inhibitors (CNI) cyclosporine and tacrolimus remain the cornerstones of immunosuppressive regimens in many centers worldwide, regardless of their well described side-effects, including nephrotoxicity. In this article, we review recent CNI-minimization strategies in kidney transplantation, while emphasizing on the importance of long-term follow-up and patient monitoring. Finally, accumulating data indicate that low-dose CNI-based regimens would provide an interesting balance between efficacy and toxicity.

Can immune monitoring help to minimize immunosuppression in kidney transplantation?

The serious side-effects and complications related to the life-long use of immunosuppressors in transplantation have fuelled research into their possible minimization or even complete elimination. The field of transplantation is therefore tentatively moving from a phase of empiric immunosuppression towards individualized therapy. This process is highly dependent on the development of immune monitoring tests to detect an individual 'level of risk'. Immune monitoring is a way of measuring functional and molecular correlates of immune reactivity to provide clinically useful information for therapeutic decision-making. The technological breakthroughs over the last decade provide firm grounds for the achievement of this goal. Large, multicentric and prospective studies in the near future are now crucial if these tests are to achieve the necessary approval from the regulatory authorities and promptly enter the clinic for routine use.

Minimizing immunosuppression, an alternative approach to reducing side effects: objectives and interim result

Exceptionally low acute rejection rates and excellent graft survival can be achieved with cyclosporine and tacrolimus (CNI)-based immunosuppressive protocols that incorporate antiproliferative immunosuppressants and corticosteroids. However, despite short-term success, long-term attrition of graft function and side effects of immunosuppressive agents continue to be significant problems, leaving clinicians looking for possible interventions. CNI nephrotoxicity is but one of numerous factors that may contribute to long-term damage in transplant kidneys. Metabolic, cosmetic, and neuropsychiatric complications of steroids affect quality of life after transplantation. Newer immunosuppressive agents such as mycophenolate mofetil and sirolimus (Rapa) have raised the possibility of withdrawing or avoiding CNIs or steroids altogether. In this report we review studies that address either CNI or steroid minimization strategies and discuss their risks versus benefits. Given the accumulated experience to date, in our opinion the use of CNIs and steroids as part of immunosuppressive regimens remains the proven standard of care for renal transplant patients. The long-term safety and efficacy of CNI and steroid minimization strategies needs to be further validated in controlled clinical trials with adequate long-term follow-up.

Calcineurin inhibitor-free immunosuppression in kidney transplantation

The introduction of calcineurin inhibitors (CNI) revolutionized kidney transplantation (KTx). Exceptionally low acute rejection rates and excellent graft survival could be achieved with CNI-based (cyclosporine and tacrolimus) immunosuppressive protocols. However, despite short-term success, long-term graft attrition continues to be a significant problem, thus leaving clinicians looking for possible interventions. CNI nephrotoxicity is but one of numerous factors that may be contributing to long-term damage in transplant kidneys. Therefore, newer immunosuppressive agents such as mycophenolate mofetil and sirolimus (Rapa) have raised the possibility of withdrawing or avoiding CNIs altogether. Protocols exploring these options have gained greater attention over the last few years. Herein, we review studies addressing either CNI withdrawal or CNI avoidance strategies as well as discuss the risks versus benefits of these protocols. Given the accumulated experience to date, in our opinion, the use of CNIs as a part of immunosuppressive regimens remains the proven standard of care for renal transplant patients. The long-term safety and efficacy of CNI withdrawal and avoidance strategies need to be further validated in controlled clinical trials.

Recipient age and mycophenolate mofetil as the main determinants of outcome after steroid withdrawal: analysis of long-term follow-up in renal transplantation

The long-term benefit of steroid withdrawal on patient and graft survival is unproven. Steroids were stopped within the first year after kidney transplantation in 223 consecutive low-risk patients initially treated with thymoglobulin and triple-drug therapy. The 15-year actuarial graft survival rate was 83.9%. Risk factors for graft loss were: proteinuria (hazard ratio [HR]: 6.96, P = 0.0003), creatinine >130 micromol/L (HR: 3.37, P = 0.01), recipient age <35 years (HR: 5.31, P = 0.001), and no mycophenolate mofetil (MMF) treatment (HR: 8.83, P = 0.04). Interestingly, recipient age and no MMF treatment were not risk factors in higher-risk patients in whom steroids were continued. The 2-year incidence of acute rejection following steroid withdrawal was 12.1%; the graft survival rate was lower in this group (71.1%). Our findings indicate that late steroid withdrawal results in excellent long-term outcome in most low-risk patients, but it should be attempted with caution in younger patients and when MMF is not used.

Nephrotoxic aspects of cyclosporine

Over the last 20 years cyclosporine (CsA) has improved the survival of kidney, heart, and liver transplants. However, with increasing use, evidence has accumulated that CsA therapy carries a variety of side effects, the most important being renal toxicity. CsA can lead to a wide spectrum of renal function impairments, including a marked and rapidly reversible decrease in renal hemodynamics (acute CsA nephrotoxicity), and a chronic form of renal damage that potentially progress irreversibly to end-stage renal disease (chronic CsA nephrotoxicity). All these manifestations are the consequence of the drug toxic effects on renal vessels and the tubulointerstitium. A proper diagnosis of CsA toxicity at early stages, the combination of low CsA doses with non-nephrotoxic immunosuppressants, and the development of more feasible strategies to monitor daily CsA exposure may contribute to a better CsA management, improve quality of life of transplant recipients, and prolong graft survival.

Withdrawal of cyclosporine or tacrolimus after addition of mycophenolate mofetil in patients with chronic allograft nephropathy

There has been a need for a prospective, randomized, controlled trial to determine whether the addition of mycophenolate mofetil (MMF) to a calcineurin inhibitor (CNI)-based regimen or MMF addition followed by CNI withdrawal is an effective treatment for chronic allograft nephropathy (CAN). We conducted the first randomized, prospective study to compare the introduction of MMF with or without CNI withdrawal in long-term transplant recipients with histologically proven CAN and deteriorating renal function. The primary endpoint was renal function as indicated by the slope of the inverse serum creatinine vs. time at 32 weeks after randomization. After an interim analysis found a greater-than-expected difference between groups in the slopes of the inverse serum-creatinine, the study was stopped for ethical reasons. There were 20 patients in the MMF/CNI continuation and 19 patients in the MMF/CNI withdrawal groups (mean time post-transplant 7 years). Renal function improved in the dual-therapy compared with the triple-therapy group (p=0.002). Blood pressure decreased in the dual-therapy group with a significant difference between groups at 35 weeks (p=0.04). No acute rejections occurred. Long-term patients with CAN experience a significant improvement in renal function and blood pressure when CNIs are replaced by MMF.

Detection of regulatory cells as an assay for allograft tolerance in miniature swine

BACKGROUND

There is currently a great need for an in vitro assay to assess the presence of tolerance following allotransplantation to determine whether immunosuppressive medications can be discontinued. Our laboratory has recently developed an assay involving coculture inhibition of cell-mediated lympholysis that correlates with tolerance to allografts in swine leukocyte antigen (SLA) Class I-mismatched miniature swine. The potential for clinical application of this assay may depend on 2 important factors: (1) whether the assay can be used in the presence of immunosuppression; and (2) whether frozen-stored naive responder cells can be utilized.

METHODS

Long-term tolerant MGH miniature swine that had accepted SLA Class I-mismatched kidney transplants after a 12-day course of cyclosporine or tacrolimus were studied. Two long-term tolerant and 2 naive control animals were treated with a clinically relevant dose of cyclosporine for 2 weeks (trough level 100 to 400 ng/ml) to simulate the ongoing "chronic" immunosuppression used in human recipients of allografts. Cells from tolerant or naive, recipient-matched animals were stimulated for 6 days with donor or third-party SLA. These primed cells were then cocultured with naive unstimulated recipient major histocompatibility complex (MHC)-matched responders and irradiated stimulators. Responder cells were tested both fresh and frozen.

RESULTS

Suppression of cytotoxic responses of naive responder cells was observed in all coculture assays using cells from tolerant animals primed against donor antigen in vitro, but not in assays using similarly primed cells from naive animals. Responder cells from tolerant animals receiving immunosuppression had a suppressive activity similar to that from cells of the same animals not receiving immunosuppression. Similar suppression was also observed in coculture assays using either fresh or frozen naive responder cells.

CONCLUSIONS

This coculture assay appears to correlate with the presence of tolerance under conditions applicable to the clinical setting. The assay appears to identify peripheral regulatory mechanisms of tolerance in allogeneic transplant recipients, and therefore may provide an approach for determining an appropriate timepoint at which to test withdrawal of immunosuppressive medications.

Conversion from cyclosporine to azathioprine at three months reduces the incidence of chronic allograft nephropathy

BACKGROUND

Conversion from cyclosporine to azathioprine after renal transplantation has been shown to be beneficial in terms of allograft function, cardiovascular risk factor profile, and the incidence of gout. A higher incidence of acute rejection, however, has also been reported and uncertainty still exists about the long-term outcome after conversion. We report on the extended follow-up of an open-label, randomized trial that examined conversion to azathioprine as early as three months after transplantation.

METHODS

One hundred twenty-eight patients were enrolled in this single-center study. Three months after transplantation they were randomly assigned to continue cyclosporine treatment (N = 68), or they were converted to azathioprine (N = 60). The steroid dose was temporarily increased in the patients who were converted.

RESULTS

Patient survival was not different in the two groups. Graft survival tended to be lower (64.7% vs. 76.5% at 15 years) in the cyclosporine continuation group (P = 0.14) when data were analyzed on an intention to treat basis. The graft survival of the patients that stayed on their assigned treatment was significantly higher in the azathioprine arm, starting at two years' post-transplantation. The glomerular filtration rate was significantly higher in the patients who were converted to azathioprine. More allograft biopsies were taken from patients remaining on cyclosporine for suspicion of cyclosporine-related nephrotoxicity and prompted a high rate of late conversions (19%). The relative risk of chronic allograft nephropathy was significantly higher in the group that continued cyclosporine [relative risk, 4.3 (95% CI, 1.4 to 12.9); P = 0.009]. Conversion to azathioprine reduced the need of blood pressure and lipid-lowering drugs.

CONCLUSION

Conversion to a calcineurin inhibitor-free immunosuppressive regiment three months after renal transplantation improved allograft function, reduced the need of cardiovascular risk factor-controlling medication, and reduced the incidence of chronic allograft nephropathy.

Amelioration of tacrolimus-induced nephrotoxicity in rats using juniper oil

BACKGROUND

Calcineurin-inhibitor nephrotoxicity plays a role in the pathogenesis of chronic allograft nephropathy by causing renal ischemia mediated by vasoconstrictive metabolites of the prostanoid pathway. The purpose of our study was to evaluate whether altering the prostanoid profile using juniper oil (JO) would afford renoprotection in rats treated with tacrolimus.

METHODS

Diets supplemented with biologic oils (no supplementation, JO, fish oil [FO], safflower oil [SO], and arachidonic acid [AA]) were fed to five groups of rats for 5 weeks; during the last 2 weeks, tacrolimus was administered to all groups except for a control group of animals. At week 5, urinary prostaglandin (PG)F(2-alpha) and inulin clearances were measured. The rat kidneys were harvested to determine the renal cell membrane composition for arachidonic, eicosatrienoic, and eicosapentaenoic acids.

RESULTS

Both JO and FO completely reversed the decrease in inulin clearance seen with tacrolimus, the greatest effect being with JO (inulin clearance 15.1+/-3 vs. 6.0+/-1.1 ml/min in the nonsupplemented group; P<0.001); urinary PGF(2-alpha) excretion was also highest in the JO group (328+/-23 pg/mL, P<0.001 vs. the nonsupplemented group). Fatty acid membrane analysis showed greatest incorporation of eicosapentaenoic and eicosatrienoic acids in the JO- (5.7+/-0.6% and 3.1+/-0.4%, respectively) and FO- (8.1+/-0.7% and 2.8+/-0.6%, respectively) treated animals.

CONCLUSIONS

JO supplementation in tacrolimus-treated rats was associated with incorporation of vasodilatory prostanoids in the renal-cell membrane and elevated urinary PGF(2-alpha) excretion, and the precipitous fall in inulin clearance induced by tacrolimus was completely prevented. Whether this benefit will translate into a reduction in chronic allograft nephropathy remains to be determined. However, our preliminary data point towards the need for human trials.

Oral ulcers in kidney transplant recipients treated with sirolimus and mycophenolate mofetil

BACKGROUND

In an attempt to reduce calcineurin inhibitor toxicity, transplant patients treated with tacrolimus can be switched to maintenance treatment with sirolimus.

METHODS

In a prospective, randomized, multicenter trial, 33 kidney transplant recipients on steroid-free maintenance treatment with tacrolimus and mycophenolate mofetil continued tacrolimus and mycophenolate mofetil (control group, n=18) or were converted from tacrolimus to sirolimus (study group, n=15) at 1 year after transplantation.

RESULTS

The study was prematurely stopped as a result of a cluster of nine patients suffering from painful oral ulcerations in the study group. Oral ulcerations did not occur in the control group. The authors here report on the individual cases suffering from this side effect of the instituted immunosuppressive regimen.

CONCLUSIONS

The authors review the literature with respect to the occurrence of oral ulcers associated with the use of sirolimus or mycophenolate mofetil and speculate on the causes of the high incidence of oral ulcers in their study group. Possible explanations are overimmunosuppression during the period of the conversion from tacrolimus to sirolimus without antiviral prophylaxis, the use of the oral emulsion instead of tablets, or the lack of corticosteroid co-administration.

Renal transplantation: can we reduce calcineurin inhibitor/stop steroids? Evidence based on protocol biopsy findings

How to combine antirejection drugs and which is the optimal dose of steroids and calcineurin inhibitors beyond the first year after kidney transplantation to maintain adequate immunosuppression without major side effects are far from clear. Kidney transplant patients on steroid, cyclosporine (CsA), and azathioprine were randomized to per-protocol biopsy (n = 30) or no-biopsy (n = 29) 1 to 2 yr posttransplant. Steroid or CsA were discontinued or reduced on the basis of biopsy to establish effects on drug-related complications, acute rejection, and graft function over 3 yr of follow-up. Serum creatinine, GFR (plasma clearance of iohexol), RPF (renal clearance of p-aminohippurate), CsA pharmacokinetics, and adverse events were monitored yearly. At the end, patients underwent a second biopsy. Per-protocol biopsy histology revealed no lesions (n = 5, steroid withdrawal), CsA nephropathy (n = 13, CsA discontinuation/reduction), or chronic rejection (n = 12, standard therapy). Reducing the drug regimen led to overall fewer side effects related to immunosuppression as compared with standard therapy or no-biopsy. Steroids were safely stopped with no acute rejection or graft loss. Complete CsA discontinuation was associated with acute rejection in the first four patients. Lowering CsA to low target CsA trough (30 to 70 ng/ml) never led to acute rejection or major renal function deterioration. Biopsy patients on conventional regimen had no acute rejection, one graft loss, no significant change in GFR, and significant RPF decline. No-biopsy controls: no acute rejection, one graft loss, significant decline of GFR and RPF. By serial biopsy analysis, severe lesions did not develop in patients with steroid discontinuation in contrast to patients on standard therapy over follow-up. CsA reduction did not adversely affect histology. Per-protocol biopsy more than 1 yr after kidney transplantation is a safe procedure to guide change of drug regimen and to lower the risk of major side effects.

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.

Withdrawal of cyclosporine or prednisone six months after kidney transplantation in patients on triple drug therapy: a randomized, prospective, multicenter study

Uncertainty exists regarding the necessity of continuing triple therapy consisting of mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisone (Pred) after kidney transplantation (RTx). At 6 mo after RTx, 212 patients were randomized to stop CsA (n = 63), stop Pred (n = 76), or continue triple drug therapy (n = 73). The MMF dose was 1000 mg twice daily, target CsA trough levels were 150 ng/ml, and Pred dose was 0.10 mg/kg per d. Follow-up was until 24 mo after RTx. Biopsy-proven acute rejection occurred in 14 (22%) of 63 patients after CsA withdrawal compared with 3 (4%) of 76 in the Pred withdrawal group (P = 0.001) and 1 (1.4%) of 73 in the control group (P = 0.0001). Biopsy-proven chronic rejection was present in one patient in the control group, in nine patients after CsA withdrawal (P = 0.006 versus control group); and in four patients after discontinuation of Pred (NS). Graft loss occurred in two versus one patient after CsA or Pred withdrawal, respectively, and in two patients in the control group (NS). Patients who successfully withdrew CsA had a significantly lower serum creatinine during follow-up. Pred withdrawal resulted in a reduction in mean arterial pressure, and the total cholesterol/HDL ratio increased. In conclusion, rapid CsA withdrawal at 6 mo after RTx results in a significantly increased incidence of biopsy-proven acute and chronic rejection. Pred withdrawal was safe and resulted in a reduction in mean arterial pressure. However, patient and graft survival and renal function 2 yr after RTx were not different among groups.

Defining the risk of elective cyclosporine withdrawal in stable kidney transplant recipients

Although it is known that elective cyclosporine (CsA) withdrawal increases the risk for acute rejection, few studies have been large enough to identify risk factors for acute rejection after CsA withdrawal. We examined risk factors for acute rejection in 464 kidney transplant recipients who underwent elective CsA withdrawal. The incidence of acute rejection within 6 months of CsA withdrawal was 20/141 (14.2%) in the period January 1986 to May 1989, but only 14/323 (4.5%) since May 1989 (p = 0.0002). Among those transplanted since May 1989, the incidence was 5/20 (25%) for those with both 2 HLA-B and 2 HLA-DR mismatches, compared with only 9/298 (3.0%) for those with fewer mismatches (p < 0.0001). In Cox proportional hazards analysis, risk factors for acute rejection within 6 months, or at any time after elective CsA withdrawal, were date of transplant January 1986 to May 1989 (compared with more recently May 1989 to March 1999), younger age, obesity, as well as B and DR mismatches. Recipient race (83% were white), acute rejection during the first year before withdrawal (31%), mycophenolate mofetil (17%), and other variables failed to predict postwithdrawal acute rejection. We concluded that avoiding CsA withdrawal in the relatively small number of recipients with both 2 HLA-B and 2 HLA-DR mismatches could further reduce our already low incidence of acute rejection following elective CsA withdrawal.

Open randomized trial comparing early withdrawal of either cyclosporine or mycophenolate mofetil in stable renal transplant recipients initially treated with a triple drug regimen

Cyclosporine (CsA) is the current primary immunosuppressant for the prevention of renal allograft rejection. Its chronic use is associated with various adverse effects like hypertension, hyperlipidemia, and nephrotoxicity, which in turn may contribute to chronic allograft nephropathy and cardiovascular mortality. This study compares a CsA-free maintenance regimen of mycophenolate mofetil (MMF) and corticosteroids with CsA and corticosteroids after early conversion from triple drug therapy. Eighty-four renal transplant recipients who had stable graft function on triple drug therapy with MMF, CsA, and steroids were randomly assigned to be withdrawn from either CsA (n = 44) or MMF (n = 40) at 3 mo posttransplantation. Kidney function at 1 yr was the primary endpoint. Secondary parameters of efficacy were patient and graft survival, incidence of acute rejection episodes, BP, and lipids. At study entry, the alternative treatment groups were similar with respect to demographics, renal function, dosage of CsA, BP, and concomitant medication. Both the creatinine clearance (71.7 versus 60.9 ml/min) and calculated GFR (73.2 versus 61.9 ml/min) were significantly better in MMF-treated patients at 1 yr. Conversion to MMF was associated with a decline of systolic and diastolic BP (128/76 versus 139/82 mmHg) and with a more favorable lipid profile. There was no difference in patient survival (100%) and graft survival (97.7% versus 100%). Acute rejection episodes occurred more frequently after withdrawal of CsA (11.3% versus 5.0%), but the difference was NS. Early tapering of CsA can safely be accomplished in renal transplant recipients who are stable on a triple drug regimen with MMF, thereby resulting in improved renal function, a more favorable lipid profile, and beneficial effects on posttransplant hypertension.

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.

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

Cyclosporin A (CsA) withdrawal after 1 yr of stable graft function has been shown to be beneficial in cadaveric renal transplantation. This strategy could be even more suitable for 'immunologically advantaged' grafts as in live related renal transplantation. We report the long-term outcome of patients in a live related transplantation programme undergoing early (between 1989 and 1992) and late (1993 onwards) CsA withdrawal as compared with those on long-term low dose CsA (1993 onwards). Two-hundred and fifty-two patients were divided into three groups based on the following immunosuppressive protocol: group ECyW (n=99), early CsA withdrawal (9 months after transplantation); group LCyW (n=44), late CsA withdrawal (median 16 months, range 13--22 months after transplantation); and group LDCy (n=109), long-term low dose CsA. The median period of follow-up was 66 months after transplantation (range 43--84 months). There was no difference in the actuarial 6-yr patient or graft survival among the three groups. Acute rejection episodes were more frequent in ECyW (54.4%) than in LDCy (31.8%) and LCyW (23.8%) (p=0.001). The risk of developing late (> or =9 months) acute rejection was highest in ECyW 32/99 (32.3%) as compared with LCyW 8/44 (18.4%; p=0.08) and LDCy 8/109 (7.3%; p=0.0001). Of the 32 ECyW patients who developed acute rejection episodes after CsA withdrawal, 13 (40.6%) lost their grafts either due to uncontrolled acute rejection or to chronic rejection. Chronic rejection was higher in ECyW (24%) than in LCyW (11%; p=0.04) and LDCy (17%; p=0.17). Antihypertensive requirement was highest in patients maintained on low dose CsA. Graft function, as measured by serum creatinine levels, was significantly better in LCyW (1.24+/-0.4 mg%) as compared with ECyW (1.49+/-0.5 mg%) and LDCy (1.48+/-0.6 mg%). Early CsA withdrawal after live related renal transplantation is associated with a significant risk of acute rejection and subsequent chronic rejection. Slow withdrawal after 1 yr is safe and more economical than the long-term administration of low dose CsA.

Impact of cyclosporine withdrawal on living related renal transplants: a single-center experience

High treatment costs force the discontinuation of cyclosporine (CSA) in a vast majority of renal transplant recipients in India. The impact of CSA withdrawal among 108 living related renal transplant recipients 12.54 +/- 4.2 months after transplantation was studied retrospectively. In 83 patients, CSA was withdrawn over a 12-week period (group I). Azathioprine dosage was increased to 2 to 2.5 mg/kg/d, and prednisolone, to 30 mg/d 2 weeks and 1 week before starting CSA withdrawal, respectively. In the other 25 patients, CSA had to be withdrawn faster (mean, 28.52 +/- 14.18 days; group II). Twenty-nine rejection episodes (26.9%) were noted in 22 patients (20.4%; 19% in group I and 52% in group II; P: = 0.008). Fifteen group-I patients (18%) and 11 group-II patients (44%) died or lost their grafts (P: = 0.017). There was no difference in age, donor source, HLA matches, pretransplantation cross-match positivity, delayed graft function, immunosuppressive drug doses, rejection episodes, or prewithdrawal serum creatinine levels between the patients who did or did not develop acute rejection after CSA withdrawal. On follow-up, 10 patients (50%) died or returned to dialysis among the rejection group compared with 16 patients (18%) in the nonrejection group (P: = 0.007). The mean creatinine level at last follow-up was greater in the rejection group (3.97 +/- 2.54 versus 1.65 +/- 1.1 mg/dL; P: < 0.001). CSA withdrawal because of economic constraints carries a significant risk for acute rejection and death and/or graft loss in Indian living donor renal transplant recipients, even after 12 months.

A meta-analysis of immunosuppression withdrawal trials in renal transplantation

Since the publication of previous meta-analyses of cyclosporine (CsA) and prednisone withdrawal in renal transplant recipients, several additional randomized controlled trials with longer follow-up have been reported. Currently, in nine prednisone withdrawal trials (n = 1461), the proportion of patients with acute rejection was increased by 0.14 (95% confidence interval = 0.10 to 0. 17, P < 0.001). In nine prednisone withdrawal trials (n = 1899), the relative risk (RR; RR = 1.0 indicates no risk) of graft failure after withdrawal was also increased (RR = 1.40; range, 1.09 to 1.70, P = 0.012). There was no evidence of between-study heterogeneity for either acute rejection or graft failure in the prednisone withdrawal trials by a chi(2) test (P > 0.05). In 10 CsA withdrawal trials (n = 1049), the proportion of patients with acute rejection was increased by 0.11 (0.07 to 0.15, P < 0.001). In 12 trials (n = 1151), the RR of graft failure after CsA withdrawal was 1.06 (95% confidence interval, 0.82 to 1.29, P = 0.646), but a chi(2) test indicated that there was study heterogeneity. However, there was no evidence of heterogeneity in the six studies (n = 632) with at least 4.0 yr (5.8 +/- 1.7) of follow-up (RR = 0.92; range, 0.64 to 1.20, P = 0.569) or in the seven trials (n = 962) published in peer-reviewed journals (RR = 0.95; range, 0.70 to 1.20 P = 0.682). Finally, in three trials (n = 259) that compared CsA and prednisone withdrawal, there was a nonsignificant trend for less graft failure with CsA withdrawal (RR = 0.63; range, 0.08 to 1.16, P = 0.190). Thus, unlike prednisone withdrawal, CsA withdrawal in select patients seems to impart little risk of long-term graft failure.

Withdrawal of mycophenolate mofetil in stable renal transplant recipients

BACKGROUND

Mycophenolate mofetil (MMF) has been demonstrated to decrease episodes of acute rejection in renal transplant recipients during the first year after transplantation. The utility of MMF after 1 year is less clear.

METHODS

Forty-five stable renal transplant recipients on maintenance therapy of cyclosporine microemulsion, MMF, and prednisone had MMF withdrawn at approximately 1 year after transplantation. A matching concurrent group of 45 stable renal transplant recipients served as the case control group.

RESULTS

Two of 45 patients in the MMF withdrawal group suffered an acute rejection episode as opposed to 1 of 45 in the control group. Both patients who rejected in the withdrawal group had adequate cyclosporine levels and had no recent decrease in prednisone dose. There was no evidence of an increased incidence of proteinuria or increased creatinine levels in the MMF withdrawal group.

CONCLUSION

In general, withdrawal of MMF in stable renal transplant recipients is well tolerated. No increased risk of rejection could be demonstrated in this patient group. A larger study will be needed to confirm our result.

Impact of dyslipidaemia in renal transplant recipients

The evidence that lipid disorders in patients following renal transplantation play a major role in the pathogenesis of atherosclerosis and chronic renal allograft rejection is circumstantial. The absolute rate of clinical vascular disease and cardiovascular complications in transplant patients, the high prevalence of an atherogenic lipid profile and the evidence from the large HMG-CoA reductase inhibitor (statin) regression trials in the general population suggest that lipid lowering treatment is necessary in most patients after renal transplantation. Furthermore, animal models and observational studies in patients have found correlations between plasma lipid levels and both acute and chronic rejection. Animal transplant models and clinical trials in heart transplant patients also suggest that statin treatment decrease the incidence of chronic rejection in a manner that may also be independent of lipid lowering. Although the mechanisms behind this protective effect remains unclear, statins may be the first agents to be effective in preventing chronic rejection and in reducing the rate of cardiovascular complication in renal transplant recipients.

Immunosuppressant-induced nephropathy: pathophysiology, incidence and management

Immunosuppressant-induced nephrotoxicity, in particular chronic progressive tubulointerstitial fibrosis/arteriopathy induced by the calcineurin inhibitors cyclosporin and tacrolimus, has become the 'Achilles heel' of immunosuppressive agents. The use of calcineurin inhibitors as primary immunosuppressants in hepatic and cardiac transplantation has led to end-stage renal disease and dialysis. Calcineurin inhibitor-induced acute renal failure may occur as early as a few weeks or months after initiation of cyclosporin therapy. The clinical manifestations of acute renal dysfunction are caused by vasoconstriction of renal arterioles, and include reduction in glomerular filtration rate, hypertension, hyperkalaemia, tubular acidosis, increased reabsorption of sodium and oliguria. The acute adverse effects of calcineurin inhibitors on renal haemodynamics are thought to be directly related to the cyclosporin or tacrolimus dosage and blood concentration. However, new clinical data indicate that calcineurin inhibitor-induced chronic nephropathy can occur independently of acute renal dysfunction, cyclosporin dosage or blood concentration. Several strategies have been evaluated to attenuate cyclosporin-induced nephropathy, but their efficacy remains unknown. Cytokine release syndrome associated with the use of muronomab-CD3 (OKT-3) can also contribute to the pathogenesis of transient acute tubular necrosis and renal dysfunction following renal transplantation. Continued research and clinical experience should provide information regarding the aetiology of cyclosporin-induced chronic progressive tubulointerstitial fibrosis/arteriopathy and its potential treatment.

Issues in cyclosporine drug substitution: implications for patient management

Substantial improvements in short-term and long-term outcomes for kidney transplant recipients have resulted from better use of existing immunosuppressive agents and newer treatment options. Calcineurin inhibitors (e.g., cyclosporine and tacrolimus) remain the foundation of immunosuppressive therapy. These agents are considered critical-dose drugs because of their narrow therapeutic range, variable pharmacokinetics, formulation-dependent bioavailability, and negative clinical consequences of underdosing or overdosing. With the recent introduction of a new cyclosporine formulation, concern exists that current bioequivalence guidelines for generic approval may not provide adequate assessment of the safety and efficacy of critical-dose drugs. Transplant experts at 2 recent conferences recommended more rigorous criteria for bioequivalence testing of critical-dose drugs and adoption of consistent drug substitution practices. Additional recommendations included specifying the intended formulation and instituting appropriate monitoring whenever formulations are switched. A summary of the outcomes of these conferences and practice implications for transplant coordinators is discussed.

Role of circulating lipid abnormalities in chronic renal allograft rejection

The evidence that circulating lipid abnormalities may play a role in the pathogenesis of chronic renal allograft rejection is tantalizing but circumstantial. In animal models of cardiac and aorta allograft rejection, lipogenic diets accelerate vascular injury, and treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors reduce vascular injury. Histological studies have demonstrated foam cells and apolipoprotein deposits in the intima of arteries from chronically rejecting human kidneys. Observational studies have found correlations between plasma lipid levels and both acute and chronic rejection. The association between lipid levels and acute rejection in cyclosporine A (CsA)-treated renal transplant recipients suggests the possibility that plasma lipids may influence the immunosuppressive effects of CsA by modulating the lipoprotein-free levels of CsA. If true, such an effect could also explain the result of recent controlled trials showing that HMG-CoA reductase inhibitors reduced graft coronary artery disease and that they prolonged survival in heart transplant recipients. In any case, the hypothesis that circulating lipid abnormalities contribute to chronic renal allograft rejection deserves further testing in well-designed, clinical trials.

Withdrawal of immunosuppression: implications for composite tissue allograft transplantation

Complete or partial withdrawal of immunosuppression is a desirable goal for physicians managing solid organ transplant recipients and has particular appeal for the management of composite tissue allograft recipients. Experience to date with steroid withdrawal or cyclosporine withdrawal in organ transplant recipients suggests that the risks of acute rejection are minimized with slow tapering of the drugs and when drug withdrawal is attempted many months or years after transplantation. Unfortunately, the full benefits of withdrawing any component of a multidrug immunosuppression regimen can probably be achieved only when the drug is withdrawn relatively early after transplantation. Thus, there is a need for improved immunologic monitoring to facilitate withdrawal of immunosuppression in any setting. Because steroid withdrawal might be particularly advantageous to the recipient of a composite tissue allograft, further experience is needed to determine the safety of steroid withdrawal with newer immunosuppressants such as tacrolimus, mycophenolate mofetil, and sirolimus.

Maintenance pharmacological immunosuppressive strategies in renal transplantation

Current maintenance immunosuppressive regimens for transplantation are based on three classes of drugs: corticosteroids, immunophilin-binding agents (eg, cyclosporin and tacrolimus), and antimetabolites (eg, azathioprine and mycophenolate). Drugs from the various classes inhibit the immune system at different points and are thus synergistic when used in combination.

Benefits of continued cyclosporine through an indigent drug program

Financial circumstances force some stable renal transplant recipients to discontinue cyclosporine (CsA). Previous results from our center document a subgroup of these patients at increased risk for acute rejection and allograft loss, namely, those of African ancestry. After 1988, such disadvantaged recipients have been able to receive CsA at no charge through the National Organization for Rare Disorders (NORD). At the University of Alabama at Birmingham, 54 patients were enrolled in the NORD program between 1988 and 1994. Acute rejection, allograft survival, and patient survival in these patients were compared with those in 42 patients who, prior to 1988, were withdrawn from CsA for financial reasons. Both groups were similar socioeconomically. The mean follow-up was 69 +/- 33 months (+/-SD) in the withdrawal group and 45 +/- 14 months in those entering the NORD program. Acute rejections occurred with similar frequency in both groups before CsA withdrawal (45%) or NORD enrollment (48%). In contrast, acute rejections were more common in patients after the onset of CsA withdrawal (38%) than after NORD enrollment (11%) (P < 0.01). Black patients withdrawn from CsA experienced more acute rejections than their counterparts in the NORD program (57% v 15%) (P < 0.01). White NORD recipients also experienced fewer acute rejections, although the difference was not statistically significant (withdrawal group 16% v NORD group 4%; P = 0.29). Rejection episodes were accompanied by reduced graft survival in black patients withdrawn from CsA, while significant improvement was seen in those remaining on CsA-based therapy (P < 0.05). No difference in allograft survival was seen among white patients in either group (withdrawal group 74% v NORD group 82%; P = 0.33). Thus, long-term access to CsA through the NORD program reduced acute rejections and improved allograft survival in an economically disadvantaged subgroup of renal transplant recipients. These findings emphasize the importance of continued access to CsA in black renal transplant recipients and its influence on long-term allograft survival.

Randomized, prospective trial of cyclosporine monotherapy versus azathioprine-prednisone from three months after renal transplantation

Cyclosporine (CsA) and prednisone (Pred) are the mostly used drugs for immunosuppression after renal transplantation, but both drugs have marked side effects. Either replacement of CsA by azathioprine (Aza) or withdrawal of prednisone (Pred) resulting in CsA monotherapy can be employed to circumvent the adverse effects in the long run. Both treatment regimens were compared to this prospective randomized trial in patients who were treated with CsA and Pred during the first 3 months after renal transplantation (CsA: n=64, Aza-Pred: n=63, median duration of follow-up: 3.9 years). Estimated graft survival rates at 5 years after transplantation (in patients with a functioning graft at 3 months) were 78% in the CsA group and 87% in the Aza-Pred group. The incidence of a rejection within 3 months after start of steroid withdraw or conversion from CsA to Aza was 30% and 25% respectively (NS). At 2 years after transplantation, serum creatinine levels were lower in the Aza-Pred group (126+/-35 micromol/L) than in the CsA group (180+/-78 micromol/L; P>0.001). There were no differences in blood pressure or incidence of infections between the treatment groups. Treatment-related costs were measured during the first year after transplantation and were lower in the Aza-Pred group (DFL 40,882+/-18,895 vs. DFL 53,484+/-44,828; 1 DFL [Dutch guilder] is about US $0.60; P<0.005). In conclusion, CsA monotherapy and Aza-Pred treatment from 3 months after renal transplantation are comparably effective immunosuppressive treatment regimens, although Aza-Pred therapy results in better graft function. Withdrawal of steroids and replacement of CsA by Aza both carry a substantial risk of rejection. The previously demonstrated cost effectiveness of CsA-containing therapies seems to be limited to the first phase after transplantation. Conversion to Aza-Pred at 3 months after transplantation reduces costs.

Chronic renal allograft rejection: immunologic and nonimmunologic risk factors

The pathogenesis of chronic renal allograft rejection is unknown. It is also unclear why cyclosporine has failed to prevent chronic rejection. We examined possible risk factors for graft loss to chronic rejection among 706 renal transplants using the Cox proportional hazards model with fixed and time-dependent covariates. Both the number and the severity of acute rejection episodes were independent risk factors for chronic rejection [relative risk (95% confidence interval) 2.31 (2.04 to 2.60) and 1.53 (1.27 to 1.84), respectively]. Cyclosporine and cyclosporine withdrawal had no effect on chronic rejection. Acute rejections occurring within the first three months after transplantation, when cyclosporine most effectively prevented acute rejection, also had no effect on chronic rejection. Risk factors that were independent of acute rejection and not clearly attributable to immune mechanisms included serum albumin [0.20 (0.10 to 0.38) for each g/dl], proteinuria [1.42 (1.29 to 1.57) for each g/24 hr], and serum triglycerides -1.09 (1.03 to 1.16) for each 100 mg/dl-. These results suggest that the reduction in acute rejection episodes from cyclosporine has failed to reduce graft failure from chronic rejection, possibly because the early (within the first 3 months) and mild acute rejection episodes that are most effectively prevented by cyclosporine do not cause chronic rejection. In addition, the results suggest that there may be a number of nonimmunologic risk factors for chronic rejection.

Late withdrawal of cyclosporine in stable renal transplant recipients

The use of cyclosporine (CsA) in renal transplantation has been associated with an improvement in 1-year graft survival, but has not changed the rate of late graft loss. We sought to determine whether the intent to withdraw CsA late after renal transplantation affects renal transplant survival and whether there is a racial difference in the effect of CsA withdrawal. This retrospective study included 384 consecutive patients receiving a renal transplant during the 1984 to 1991 period who were treated with CsA/azathioprine/prednisone and who had a functioning allograft 6 months following transplantation. Of these, 97 were electively withdrawn from CsA at a median of 22 months following transplantation. Factors significantly associated with the decision to withdraw CsA included white race, older age, and lower serum creatinine. Acute rejection within 6 months of stopping CsA occurred in 12 patients (12.4%), including nine of 78 (11.5%) white patients and three of 19 (15.8%) black patients. For the group of 287 patients who were not withdrawn from CsA, the 6-year graft survival rate was 59% (95% confidence interval, 52%, 66%). For the group of patients taken off of CsA, the 6-year graft survival rate was 84% (95% confidence interval, 76%, 92%). Cox proportional hazard survival analysis indicated that the intent to discontinue CsA was associated with better graft survival, with a hazard ratio of 0.37 (95% confidence interval, 0.20, 0.70), independent of other variables that may affect graft survival. A separate analysis controlling for waiting time bias also favored the CsA withdrawal group. There was no detectable racial difference in the effect of CsA withdrawal on graft survival.(ABSTRACT TRUNCATED AT 250 WORDS)