Cyclosporine withdrawal for nephrotoxicity in liver transplant recipients does not result in sustained improvement in kidney function and causes cellular and ductopenic rejection

Minimization or withdrawal of immunosuppressants in pediatric liver transplant recipients

BACKGROUND

We aimed to minimize the dose of tacrolimus in pediatric patients undergoing liver transplantation prospectively.

METHODS

Pediatric liver transplant recipients with stable graft function >1year (transplant at <1year of age), or 2years (transplant at >1year of age) post transplant were screened. After baseline graft biopsy, patients were enrolled into our protocol for elective tacrolimus dose reduction. Patients were assessed by liver function test and protocol biopsy during and after tacrolimus dose reduction.

RESULTS

From January 2011 to December 2012, 16 patients were recruited, of whom 15 completed follow-up at a mean 40.75±5.98months. Six patients were preliminarily weaned off tacrolimus, and five remained tacrolimus-free for more than 2years. Of the 10 patients who were not weaned off tacrolimus, six experienced seven episodes of clinical rejection. Five patients had a reduction in tacrolimus dosage to an undetectable trough level, another five to a trough level <4ng/ml, including one patient who was off the study. At the last patient visit, all of the patients had normal liver function test results with no graft loss. Three patients had low-grade graft fibrosis. The patients with metabolic liver disease (p=0.039) and who were recruited earlier after transplantation (p=0.028) were more likely to be weaned off tacrolimus.

CONCLUSION

Tacrolimus withdrawal is feasible in select pediatric liver transplant recipients, and long-term follow-up for these patients is suggested.

Pediatric transplantation and tolerance: past, present, and future

Solid organ transplantation is the treatment of choice in children with end-stage organ failure. With improving methods of transplant surgery and post-transplant care, transplantation is more frequently performed worldwide. However, lifelong and non-specific suppression of the recipient's immune system is a cause of significant morbidity in children, including infection, diabetes, and cancer. There is a great need to develop IS minimization/withdrawal and tolerance induction approaches.

Expression of alpha smooth muscle actin in living donor liver transplant recipients

Recently, there have been reports from liver biopsies that showed the progression of liver fibrosis in liver transplant patients after the cessation of immunosuppression. Herein, we focused on activated hepatic stellate cells expressing alpha smooth muscle actin (α-SMA) to understand the correlation between immunosuppressant medication and liver fibrosis. The study enrolled two pediatric patients who underwent living donor liver transplantation and ceased immunosuppressant therapy. The number of α-SMA-positive cells in the specimens obtained by liver biopsy from these two patients showed a three-fold increase compared with the number from four transplanted pediatric patients who were continuing immunosuppressant therapy. In addition, the α-SMA-positive area evaluated using the WinRooF image processing software program continued to increase over time in three adult transplanted patients with liver fibrosis, and the α-SMA-positive area was increasing even during the pre-fibrotic stage in these adult cases, according to a retrospective review. Therefore, α-SMA could be a useful marker for the detection of early stage fibrosis.

Calcineurin inhibitor minimisation versus continuation of calcineurin inhibitor treatment for liver transplant recipients

BACKGROUND

The therapeutic success of liver transplantation has been largely attributable to the development of effective immunosuppressive treatment regimens. In particular, calcineurin inhibitors were essential in reducing acute rejection and improving early survival. Currently, more than 90% of all liver transplant recipients are treated with the calcineurin inhibitor cyclosporine or tacrolimus. Unfortunately, calcineurin inhibitors cause adverse events, such as nephrotoxicity, and because of this, minimisation (reduction and withdrawal) regimens of calcineurin inhibitor have been developed and studied. However, the benefits and harms of these minimisation regimens are unclear.

OBJECTIVES

To assess the benefits and harms of calcineurin inhibitor minimisation for liver transplant recipients without substitution by another immunosuppressive agent.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (Gluud 2010), Cochrane Central Register of Controlled Clinical Trials (CENTRAL) in The Cochrane Library, MEDLINE (OvidSP), EMBASE (OvidSP), Science Citation Index Expanded (Royle 2003), and the World Health Organization (WHO) international clinical trials registry platform (www.who.int/ictrp) until August 2011. In addition, we searched bibliographies of relevant articles as well as US Food and Drug Administration (FDA) and European Medicines Agency (EMA) drug approval reviews for additional trials.

SELECTION CRITERIA

We planned to select all randomised clinical trials investigating calcineurin inhibitor reduction or withdrawal in liver transplant recipients, irrespective of blinding, publication status, or language. Quasi-randomised clinical studies and cohort studies that were obtained through the searches were considered only for the reporting of harms. Trials investigating substitution of one calcineurin inhibitor by another calcineurin inhibitor were excluded. Trials investigating calcineurin inhibitor withdrawal concurrently with switching over to a mammalian target of rapamycin (mTOR) inhibitor-based regimen (everolimus or sirolimus) or mycophenolate mofetil-based regimen are the subject of a separate review.

DATA COLLECTION AND ANALYSIS

Search strategies were used to obtain titles and abstracts of studies that were relevant for the review. Two authors independently scanned the references and assessed trial eligibility.

MAIN RESULTS

A total of 1299 references were identified by the searches. After removal of duplicates, 794 references were left. Out of these, two abstract reports of one ongoing randomised trial fulfilled the inclusion criteria of the review. This ongoing trial studies total withdrawal of immunosuppression in patients who receive a calcineurin inhibitor (cyclosporine or tacrolimus) or mycophenolate mofetil as the only immunosuppressive agent. The trial compares withdrawal of calcineurin inhibitor or mycophenolate mofetil with continuation of calcineurin inhibitor or mycophenolate mofetil. However, no trial results on the outcomes of interest to this review were available.

AUTHORS' CONCLUSIONS

This review shows that strategies regarding calcineurin inhibitor minimisation, that is, reduction or withdrawal, without substitution versus continuation of calcineurin inhibitor treatment lack evidence from randomised trials.More research with calcineurin inhibitor reduction and withdrawal regimens is needed to optimise dosing and timing of calcineurin inhibitor treatment in order to achieve optimal patient and graft survival with a minimum of adverse events.Specifically regarding calcineurin inhibitor reduction versus no reduction, we recommend that randomised trials evaluating calcineurin inhibitor reduction versus continuation of calcineurin inhibitor treatment are conducted.Regarding calcineurin inhibitor withdrawal, we recommend that mechanisms for tolerance and 'graft acceptance' are clarified, and patient groups likely to tolerate calcineurin inhibitor withdrawal are identified in order to select the right patients for total withdrawal of calcineurin inhibitors without substitution with another immunosuppressive drug. The randomised trials should only be performed in highly selected patients.

Tolerance in liver transplantation

Operational tolerance (OT) in liver transplant patients occurs much more frequently than OT of other transplanted organs; however the rate of OT varies considerably with the centre and patient population. Rates of OT range from 15% of the total liver transplant (LTX) patient population down to less than 5%. This review examines the reports of liver OT and compares the factors that could contribute to this variation. Multiple factors were examined, including the time from transplantation when weaning of immunosuppression (IS) was commenced, the rapidity of weaning, the contribution of maintenance and induction IS and the patient population transplanted. The approaches that might be used to increase the likelihood of OT are discussed and the approaches to monitoring OT in LTX patients are reviewed.

Tolerance: is it achievable in pediatric solid organ transplantation?

In the clinical arena of transplantation, tolerance remains, for the most part, a concept rather than a reality. Although modern immunosuppression regimens have effectively handled acute rejection, nearly all organs except the liver commonly suffer chronic immunologic damage that impairs organ function, threatening patient and allograft survival. In addition to the imperfect control of the donor-directed immune response, there are additional costs. First, there is the burden of mortality from infection and malignancy that can be directly attributed to a crippled immune system. Second, there are insidious effects on renal function, cardiovascular profile (hypertension, hyperglycemia, and dyslipidemia), bone health, growth, psychological and neurocognitive development, and overall quality of life. It is likely that the full consequences of lifelong immunosuppression on our pediatric transplant recipients will not be fully appreciated until survival routinely extends beyond 1 or 2 decades after transplantation. Therefore, it can be argued that the holy grail of transplantation tolerance is of the utmost importance to children who undergo solid organ transplantation.

Azathioprine in liver transplantation: a reevaluation of its use and a comparison with mycophenolate mofetil

Calcineurin inhibitors (CNIs) combined with steroids with or without azathioprine (AZA), have been a standard immunosuppression regimen after liver transplantation (LT). Since 2000 many centers have substituted AZA by mycophenolate mofetil (MMF). However, in LT the superiority of MMF over AZA is not clearly demonstrated. Therefore, we questioned the benefit of MMF versus AZA in LT with regard to rejection, renal dysfunction and hepatitis C virus (HCV) recurrence and survival. Using a literature search, relevant randomized controlled trials (RCT) and cohort studies were identified: two RCTs compared MMF to AZA only for acute rejection. Treated rejection was less with MMF in only one RCT (38.5% vs. 47.7%; p = 0.025), with no difference in patient and graft survival. No RCTs compared MMF and AZA in patients with CNI-related chronic renal dysfunction. Among two studies evaluating MMF, with substitution of AZA, one was stopped due to severe rejection. Recurrent HCV was less severe in 5/9 studies with AZA compared with 2/17 using MMF, six of which documented worse recurrence. Published data in LT show little, if any, clinical benefit of MMF versus AZA. RCTs should reevaluate AZA in LT. Evaluation of HCV replication and recurrence will be particularly important as AZA may have advantages over MMF.

Microproteinuria for detecting calcineurin inhibitor-related nephrotoxicity after liver transplantation

AIM: To investigate whether microproteinuria could be used as an early and sensitive indicator to detect calcineurin inhibitor (CNI)-related nephrotoxicity after liver transplantation.

METHODS: All liver transplant recipients with normal serum creatinine (SCr) and detectable microproteinuria at baseline were included in this study. The renal function was monitored by the blood clearance of ^99mTc-diethylenetriaminepentaacetic acid every 6 mo. Microproteinuria, SCr and blood urea nitrogen (BUN) were measured at entry and at subsequent follow-up visits. The patients were divided into different groups according to the mean values of glomerular filtration rate (GFR) at the follow-up time points: Group 1, GFR decreased from baseline by 0%-10%; Group 2, GFR decreased from baseline by 11%-20%; Group 3, GFR decreased from baseline by 21%-40%; Group 4, GFR decreased from baseline by > 40% and/or SCr was increasing.

RESULTS: A total of 143 patients were enrolled into this study (23 females and 120 males). The mean follow-up was 32 mo (range 16-36 mo). Downward trends in renal function over time were observed in the study groups. SCr and BUN increased significantly only in Group 4 patients (P < 0.001). β2-microglobulin (β2m) and α1-microglobulin (α1m) significantly increased with the subtle change of renal function in recipients who were exposed to CNI-based immunosuppression regimens. The reductions in GFR were closely correlated with elevated α1m (r² = -0.728, P < 0.001) and β2m (r² = -0.787, P < 0.001).

CONCLUSION: β2m and α1m could be useful as early and sensitive indicators of CNI-induced nephrotoxicity.

Monitoring of human liver and kidney allograft tolerance: a tissue/histopathology perspective

Several factors acting together have recently enabled clinicians to seriously consider whether chronic immunosuppression is needed in all solid organ allograft recipients. This has prompted a dozen or so centers throughout the world to prospectively wean immunosuppression from conventionally treated liver allograft recipients. The goal is to lessen the impact of chronic immunosuppression and empirically identify occasional recipients who show operational tolerance, defined as gross phenotype of tolerance in the presence of an immune response and/or immune deficit that has little or no significant clinical impact. Rare operationally tolerant kidney allograft recipients have also been identified, usually by single case reports, but only a couple of prospective weaning trials in conventionally treated kidney allograft recipients have been attempted and reported. Pre- and postweaning allograft biopsy monitoring of recipients adds a critical dimension to these trials, not only for patient safety but also for determining whether events in the allografts can contribute to a mechanistic understanding of allograft acceptance. The following is based on a literature review and personal experience regarding the practical and scientific aspects of biopsy monitoring of potential or actual operationally tolerant human liver and kidney allograft recipients where the goal, intended or attained, was complete withdrawal of immunosuppression.

Chronic renal dysfunction following liver transplantation

With most of the immunosuppressive protocols consisting of calcineurin inhibitors (CI), nephrotoxicity has become a major long-term complication often compromising outcome. In a single-center retrospective study, we reviewed 1173 liver transplantations to identify variables indicative for the occurrence of chronic renal dysfunction (CRD) (defined as > or = 1 episode of serum creatinine increase > or = 1.8 mg/dL > or = 2 wk). Chronic renal dysfunction was found in 137 (11.7%) of all transplants [82 (7%) early (after 3-12 months), 55 (4.7%) late-onset (> 12 months)]. Compared to 5-/10-yr survival rates in non-CRD transplants (84/74%) survival was significantly decreased in early (66/46%), but unchanged in late-onset CRD (98/86%). Rates of alcoholic cirrhosis and prior renal dysfunction were significantly increased in patients with CRD. In a multivariate logistic regression analysis, only cyclosporine A (CyA) as immunosuppression remained an independent risk factor. No correlations to age, gender, rejection/retransplantation or diabetes were found. Surprisingly, renal function (creatinine) showed no difference between patients on CI monotherapy (FK/CyA) compared to those who had mycophenolate mofetil (MMF) added. In liver transplantation, early onset CRD significantly compromises survival. CyA-based immunosuppression appears to have a stronger impact than FK. The fact that patients with long-term severe chronic renal dysfunction failed to improve under MMF rescue therapy emphasizes the importance of new diagnostic strategies to earlier identify at-risk patients.

Randomized controlled trial of total immunosuppression withdrawal in liver transplant recipients: role of ursodeoxycholic acid

BACKGROUND

Total immunosuppression withdrawal (TIW) without causing rejection has been reported in stable liver recipients. The role of ursodeoxycholic acid (UDCA) and patient characteristics that predict the success of this tolerance are unclear. There are two goals, to determine: 1) whether TIW is frequently associated with rejection; and 2) whether UDCA decreases the risk of liver disease (both rejection and recurrence) after TIW.

METHODS

Twenty-six liver recipients who had been free of rejection while on immunosuppressive agents for a minimum of 2 years were randomized to receive either (15 mg/kg) of UDCA (n=14) or identical placebo (n=12) followed by sequential withdrawal of their immunosuppressive regimen over several months. Endpoints were defined as biochemical and histological evidence of rejection, graft dysfunction without rejection, recurrence of pretransplant disease, or 6 months without immunosuppression and no rejection or dysfunction on repeat liver biopsy.

RESULTS

Rejection occurred in 6 of 14 (43%) of the UDCA group and 9 of 12 (75%) of those receiving placebo (P=0.09). Degree of rejection was mild, moderate, and severe in 73%, 20%, and 7% of patients respectively. All responded to rescue therapy and none developed chronic rejection. Nine of the remaining 11 patients (eight of the UDCA recipients and three of controls) who did not develop rejection developed graft dysfunction which responded to reintroduction of immunosuppressive agents in each case. Disease recurrence was most common in patients with underlying immune-mediated disorders of the liver. One year after withdrawal only two patients were free of immunosuppression, 80% were able to discontinue prednisone therapy (steroid free), and 50% were able to reduce their dose of cyclosporine. Age, underlying cause of liver disease, and regimen of immunosuppression were favorable predictors.

CONCLUSIONS

The results of this study suggest that TIW: 1) is frequently associated with subsequent rejection, 2) increases the risk of underlying disease recurrence, and 3) is not facilitated by UDCA use and responds properly to the reintroduction of immunosuppressive therapy.

Reducing the risks of cardiovascular disease in liver allograft recipients

Liver allograft recipients are at increased risk of death from cerebrovascular and cardiovascular disease. We propose the following strategy of risk-reduction, based on currently available literature. Lifestyle: standard advice should be given (avoidance of smoking, excess alcohol and obesity, adequate exercise, reduction of excess sodium intake). Hypertension: target blood pressure should be 140/90 mmHg or lower, but for those with diabetes or renal disease, 130/80 mmHg or lower. For patients without proteinuria, antihypertensive therapy should be initiated with a calcium channel blocker and for those with proteinuria, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker. If monotherapy fails to achieve adequate response, calcium channel blockers and ACE-inhibitors or angiotensin II receptor blockers should be combined. If hypertension remains uncontrolled, an alpha-blocker may be added. Consideration should be given to changing immunosuppression and avoiding use of calcineurin inhibitors. Diabetes: recipients should be regularly screened for diabetes. For patients with new-onset diabetes after transplant, stepwise therapy should be guided by HbA1c concentrations, as with type II diabetes mellitus. Hyperlipidemia: annual screening of lipid profile should be undertaken, with treatment thresholds and targets based on those advocated for the high risk general population. Dietary intervention is appropriate for all patients. A statin should be considered as the first line treatment to achieve specified targets. In patients receiving a calcineurin inhibitor, Pravastatin should be commenced at a dose of 10 mg/day. In patients receiving other forms of immunosuppression, pravastatin may be commenced at a dose of 20 mg/day. Liver tests should be monitored and patients warned to report myalgia. If monotherapy is inadequate, ezetimibe or a fibrate may be added. Consideration may be given to change in immunosuppression if combination lipid-lowering therapy proves inadequate.

Mycophenolate mofetil in combination with reduction of calcineurin inhibitors for chronic renal dysfunction after liver transplantation

The purpose of the study was to introduce mycophenolate mofetil (MMF) in liver transplant recipients with renal dysfunction to decrease calcineurin inhibitor (CNI) dosages without increasing rejection risk. In this prospective, multicenter, randomized study, chronic CNI-related renal dysfunction was defined by an increase in serum creatinine with values >140 micromol/L and <300 micromol/L. Patients were randomized in 2 groups.

STUDY GROUP

combination of MMF (2 to 3 g/day) and reduced dose of CNI >or=50% of initial dose; control group: no MMF, but with the ability to reduce CNI doses, but not below 75% of initial dose. Fifty-six patients were included, 27 in the study group and 29 in the control group. In the study group, there was a significant decrease in serum creatinine values, from 171.7 +/- 24.2 micromol/L at day 0 to 143.4 +/- 19 micromol/L at month 12 and a significant increase in creatinine clearance, from 42.6 +/- 10.9 mL/min to 51.7 +/- 13.8 mL/min. No rejection episode was observed in the study group. In the control group, there was no improvement of renal function, assessed by the changes in serum creatinine values, from 175.4 +/- 23.4 micromol/L at day 0 to 181.6 +/- 63 micromol/L at month 12, and in creatinine clearance, from 42.8 +/- 12.8 mL/min to 44.8 +/- 19.7 mL/min. The differences between the 2 groups were significant: P = 0.001 for serum creatinine, and P = 0.04 for creatinine clearance. In conclusion, the introduction of MMF combined with the reduction of at least 50% of CNI dose allowed the renal function of liver transplant recipients to significantly improve at 1 year, without any rejection episode and without significant secondary effects.

Predictive factors for chronic renal failure one year after orthotopic liver transplantation

Chronic renal failure (CRF) is increasingly prevalent in solid-organ-transplant patients. This is in part related to the long-term use of calcineurin inhibitor (CNI) agents. However, in orthotopic liver-transplant (OLT) patients, the effects of superimposed hepatitis C virus (HCV)-related renal lesions could also be a factor. The aim of this cohort study (February 2000 to September, 2003) was to identify the predictive factors at one year post-transplantation for CRF in OLT patients associated with induction therapies. CRF was defined as having a creatinine clearance (CC) lower than 60 mL/min. Of the 97 transplants performed during that period, 72 were still functioning after one year. Of these, 33 patients (45.8%) had CRF. In univariate analysis, the predicting factors for CRF were recipient sex (female), initial liver disease (HCV-related cirrhosis), pre-transplant CC (<80 mL/mn), and post-transplant serum creatinine >130 micromol/L at day 3 and months (M) 1, 3, and 6. In multivariate analysis, the independent predictive factors for CRF included female sex [OR: 11.5 (2.3-58.3); p = 0.003], HCV infection [OR: 5.01 (1.1-22.7); p = 0.03], pre-OLT CC <80 mL/mn [OR: 5.4 (1.2-23.7); p = 0.025], and serum creatinine at M6 greater than 130 micromol/L [OR: 19.6 (3.7-102.5); p = 0.0004]. Among all of the predictive factors for post-OLT CRF, only one is modifiable: post-transplant serum creatinine, which could be, to some extent, related to the long-term use of CNIs.

Cyclosporine A withdrawal during follow-up after pediatric liver transplantation

It is unclear whether cyclosporine A (CsA) can be withdrawn safely during follow-up after pediatric liver transplantation. In our transplant program we have been using a strict protocol to withdraw CsA. The aim of this study was to retrospectively assess the effects of CsA withdrawal after pediatric liver transplantation on the incidence of rejection and renal function. Between 1986 and 2001, 91 children received CsA for at least 2 yr after liver transplantation. Specific criteria for eligibility to withdraw CsA were set. In 53 of the 91 children CsA was withdrawn. In 35 patients (66%) withdrawal of CsA did not cause rejection. In these patients the renal function improved compared with baseline values (glomerular filtration rate (GFR) at 1 yr, +16 mL/minute/1.73 m3, P < 0.001; at 2 yr, +10 mL/minute/1.73 m3, P < 0.05). After CsA withdrawal, 18 patients developed rejection (34%), which could be effectively treated by methylprednisolone and restarting CsA. Failure to withdraw CsA was not associated with increased incidence of graft loss. A body weight below 10 kg at the time of transplantation correlated significantly with successful withdrawal of CsA (<10 kg, 85% vs. > 10 kg, 60%; P < 0.05). In conclusion CsA can successfully be withdrawn in a major proportion of selected pediatric liver transplantation patients during follow-up. The success rate is the highest in children with a body weight below 10 kg at the time of transplantation. Successful withdrawal improves renal function, whereas failure to withdraw is not associated with graft loss or persisting morbidity.

Introduction of MMF in conjunction with stepwise reduction of calcineurin inhibitor in stable liver transplant patients with renal dysfunction

Mycophenolat mofetil (MMF) is a new imunosuppressant without nephrotoxic adverse effects. The aim of this study was to evaluate feasibility and effect of MMF introduction in conjunction with stepwise reduction of calcineurin inhibitors (CNI) in stable liver transplant patients with chronic CNI-induced renal dysfunction (RDF). In the MMF-group (n=27) but not in the controls (n=16), mean serum level of creatinine fell from a baseline of 227.4+/-67.9 micromol/l to 159.2+/-48.2 micromol/l (P<0,001), while mean urea level declined significantly from a baseline of 18.5+/-8.7 mmol/l to 11.4+/-4.2 mmol/l 6 months after initiation of MMF. Additionally, systolic and diastolic blood pressure values improved. In 52% of patients, dose reduction (n=11) or withdrawal (n=3) of MMF was necessary due to gastrointestinal or hematologic adverse effects. But also in patients on low dose MMF, there was a significant improvement of renal function without increased immunological risk.

Nonnephrotoxic immunosuppression in patients after liver transplantation

INTRODUCTION

Calcineurin inhibitor (CI)-associated renal impairment and renal failure after liver transplantation has been recognized since the early days of its use. Various strategies have been used to prevent or slow down the progression of renal dysfunction in liver transplant recipients, but did not succeed. In this report, we describe the course of renal function of 58 stable liver transplant recipients and compared 2 groups with different immunosuppressive protocols.

METHODS

In the study group, 22 patients at various intervals from liver transplantation were included. The immunosuppressive therapy consisted of Sirolimus (SRL). Additional all patients except 2 received Mycophenolate Mofetil (MMF) and 14 of them also received Tacrolimus. Patients of the control group (36 patients) had an immunosuppressive therapy with calcineurin inhibitors. Patients were monitored for creatinine monthly and creatinine clearance (CCr) every sixth month. Risk factors for renal dysfunction were evaluated.

RESULTS

After introduction of SRL in patients with renal impairment and after a mean follow-up time of 12 (2-26) months, there was a decrease of 28.3% in mean creatinine and of 41.8% in mean urea. We observed an improvement of renal function in all patients initially after introduction of SRL. In the control group, in comparison to preoperative levels, there was an increase of 27.5% in mean creatinine and of 13.3% in mean urea after a mean follow-up time of 3.6 years with CI therapy.

CONCLUSION

The results of our retrospective study showed that with SRL renal impairment could be stopped and renal function could be improved. We suggest administering immunosuppressive therapy with SRL in combination with low dose Tacrolimus and/or MMF for patients with renal impairment.

Calcineurin inhibitor nephrotoxicity: longitudinal assessment by protocol histology

BACKGROUND

The role and burden of cyclosporine (CsA) nephrotoxicity in long-term progressive kidney graft dysfunction is poorly documented.

METHODS

The authors evaluated 888 prospective protocol kidney biopsy specimens from 99 patients taken regularly until 10 years after transplantation for evidence of CsA nephrotoxicity.

RESULTS

The most sensitive histologic marker of CsA nephrotoxicity was arteriolar hyalinosis, predicted by CsA dose and functional CsA nephrotoxicity. Striped fibrosis was associated with early initiation of CsA and the need for posttransplant dialysis (both P < 0.05). The 10-year cumulative Kaplan-Meier prevalence of arteriolar hyalinosis, striped fibrosis, and tubular microcalcification was 100%, 88.0%, and 79.2% of kidneys, respectively. Beyond 1 year, 53.9% had two or more lesions of CsA nephrotoxicity. Structural CsA nephrotoxicity occurred in two phases, with different clinical and histologic characteristics. The acute phase occurred with a median onset 6 months after transplantation, was usually reversible, and was associated with functional CsA nephrotoxicity (P < 0.05), high CsA levels (P < 0.05), and mild arteriolar hyalinosis (P < 0.001). The chronic phase of CsA nephrotoxicity persisted over several biopsies, occurred at a median onset of 3 years, and was associated with lower CsA doses and trough levels (both P < 0.05). It was largely irreversible and accompanied by severe arteriolar hyalinosis and progressive glomerulosclerosis (both P < 0.001). A threshold CsA dose of 5 mg/kg/day predicted worsening of arteriolar hyalinosis on sequential histology.

CONCLUSIONS

Pathologic changes of CsA nephrotoxicity were virtually universal by 10 years and exacerbated chronic allograft nephropathy. CsA is unsuitable as a universal, long-term immunosuppressive agent for kidney transplantation. Strategies to ameliorate or avoid nephrotoxicity are thus urgently needed.

Incidence and risk factors of renal dysfunction after liver transplantation in Korea

Renal dysfunction, one of the most common complications after liver transplantation, influences patient outcomes. Little is known, however, about it in Korea. The aims of this study were to determine the incidence and to identify the risk factors for renal dysfunction after liver transplantation. Sixty-two patients who survived over 6 months after transplantation were enrolled. Renal function was classified by creatinine clearance (Ccr, mL/min), which was estimated using the Cockcroft-Gault formula. Twenty-seven patients (44%) showed mild renal dysfunction (60 < or = Ccr < 90), and 27 patients (44%), moderate dysfunction (30 < or = Ccr < 60). The others were found to have normal function (Ccr > or = 90). None displayed severe dysfunction (Ccr < 30). Compared to a control group (Ccr > or = 60), the renal dysfunction group showed lower preoperative Ccr (91 +/- 28.6, 63 +/- 21.9, respectively, P < .01) and lower Ccr at 3 months after transplantation (72 +/- 17.1, 49 +/- 14.6, respectively, P < .05). Age, sex, immunosuppressive drug usage, serum tacrolimus levels, and the frequency of postoperative acute renal failure did not affect the postoperative renal dysfunction. Twenty-six patients received mycophenolate mofetil while reducing the dose of calcineurin inhibitors because of compromised renal function. With mycophenolate mofetil treatment, the renal function seemed to improve, although the difference was not statistically significant (P = .057). These data demonstrate that renal dysfunction is common after liver transplantation and that preoperative renal function is the important factor predicting postoperative renal dysfunction.

Long-term efficacy and safety of mycophenolate mofetil in liver transplant recipients with calcineurin inhibitor-induced renal dysfunction

Long-term survival after orthotopic liver transplantation (OLT) is mainly influenced by adverse events caused by immunosuppression. Several studies have shown the efficacy of mycophenolate mofetil (MMF) in improving calcineurin inhibitor (CI)-induced nephrotoxicity with concomitant reduction or withdrawal of CI. In this prospective study we assessed the long-term effect and safety of MMF. Thirty-two OLT recipients with significant renal impairment due to either cyclosporine A ( n=25) or tacrolimus ( n=7) were enrolled in this study. CIs were reduced stepwise by at least 70%. Mean serum creatinine had decreased from 2.63+/-0.39 to 1.74+/-0.34 mg/dl after 1 month, and this improvement was maintained within a follow-up period of 4.8+/-0.6 (range 3.1-6.0) years, without major immunological or non-immunological side effects. Of all participants, 88% showed a significant reduction, and 41% even a normalization, in their serum creatinine level. In addition, MMF conversion, within 6 months of OLT, appears to be crucial in order to improve or even normalize renal function. This study demonstrates the long-term efficacy and safety of MMF in OLT recipients with CI-induced nephropathy.

DEMONSTRATION THAT DONOR-SPECIFIC NONRESPONSIVENESS IN HUMAN LIVER ALLOGRAFT RECIPIENTS IS BOTH RARE AND TRANSIENT

BACKGROUND

The side effects of lifetime immunosuppression are a major cause of morbidity and mortality; however, in the absence of prospective monitoring, immunosuppression withdrawal may lead to graft loss from rejection. To detect and monitor suitable recipients for immunosuppression withdrawal, the authors used an in vitro assay of T-cell function to study 71 long-term liver allograft recipients.

METHODS

Interleukin-2 secretion by blood mononuclear cells was measured in response to recall antigens, alloantigen (donor and third-party), and phytohemagglutinin.

RESULTS

Forty-four recipients were studied at a single time point at least 1 month after transplantation. The majority reacted to all antigens (n=33), whereas four showed globally reduced or absent responses (n=4) and six had markedly reduced or absent responses to donor alloantigen in the presence of preserved responses to third-party alloantigen and recall antigens. Four of these donor-nonresponsive recipients were retested 6 to 12 months later, by which time all had redeveloped responses to donor alloantigen. Serial measurements for up to 2 years in a prospective cohort of 27 liver allograft recipients showed only two patients to be consistently donor-nonresponsive posttransplant.

CONCLUSIONS

Most patients rapidly reacquire vigorous immune responses after liver transplantation, and only a minority are hyporesponsive to donor alloantigen. Donor-specific nonresponsiveness is transient in most patients, and serial monitoring is required to define sustained periods of donor-specific nonresponsiveness. Whether such patients are suitable for immunosuppressive withdrawal is unclear.

Mycophenolate mofetil in pediatric liver transplant patients with renal dysfunction: preliminary data

The prolonged use of CNI has been associated with nephrotoxicity. MMF is a new immunosuppressive agent. In the present study, the consequences of introducing MMF and reduction of CNI in liver-transplant children were analysed. The present study included eight pediatric liver-transplant patients who had transplantation at least 5 yr previously, had stable graft function and had renal dysfunction as a probable side-effect of CNI therapy. CNI was replaced with MMF in all patients and serum creatinine, uric acid concentration, azotemia and creatinine clearance before and 6 months after study entry were measured. The patients were monitored closely for side-effects of MMF as well as graft function. Six months after study entry serum creatinine, uric acid concentration, azotemia and creatinine clearance improved in all the patients at the last follow-up. The aspartate aminotransferase and alanine aminotransferase concentrations were stable during the study period and did not observe any serum bilirubin increased as well. No side-effects were reported in patients on MMF. Only one patient reported temporary pruritus and nausea. The results indicate that renal dysfunction significantly improved when MMF therapy is started and CNI reduced. Furthermore present data suggest that the risk of acute allograft rejection is very low when the CNI desired reduction is achieved in not too short time and absolutely when the MPA levels are strictly monitored.

Effectiveness and safety of mycophenolate mofetil as monotherapy in liver transplantation

INTRODUCTION

Calcineurin inhibitors (CIs) cause substantial long-term morbidity and mortality among orthotopic liver transplantation (OLT) patients. Our aim was to evaluate the effectiveness and safety of mycophenolate mofetil (MMF) among OLT patients with CI-related side effects.

PATIENTS

Thirty three adult patients, including 29 men and 4 women of mean age 57 years, underwent OLT between 1986 and 2000 under treatment with CIs (28 cyclosporine and five tacrolimus). Mean follow-up after OLT was 59 months. Adverse effects were renal dysfunction in 26, hypertension in 23, and neurotoxicity in two. MMF was added gradually while simultaneously reducing the dosage of CI.

RESULTS

After a mean 15-months follow-up of MMF treatment, CIs had been withdrawn in 28 patients (85%). The mean time from the initiation of MMF and CI withdrawal was 5 months. During the first year of follow-up chronic renal dysfunction improved in 16 of 26 patients (61.6%) accompanied by a decreased serum creatinine and urea and an increase in creatinine clearance. Among 13/23 (56.5%) hypertensive patients, there was a significant decrease in blood pressure or the number of antihypertensive drugs (P<.05). One patient with neurotoxicity improved. Twenty-two patients (66%) displayed adverse events: five rejections (15%) including four acute episodes, controlled by CI re-introduction, and one chronic reaction. The most frequent adverse effects were herpes simplex infection in 10 patients (30%), asthenia in nine (27%), diarrhea in five (15%) and thrombocytopenia in four (12%). Nevertheless, only six patients (19%) required MMF dose reduction, namely, three patients with GI intolerance, two with repeated VHS infections, and one with anemia.

CONCLUSIONS

MMF monotherapy improves renal function and blood pressure levels in more than 50% of patients with chronic renal impairment and hypertension after OLT. Many of the side effects of MMF were mild; it was safe accompanied by a low incidence of rejection reactions.

Treatment of renal dysfunction after orthotopic liver transplantation: options and outcomes

Chronic nephrotoxicity is one of the most serious side-effects of calcineurin inhibitor treatment and a factor in mortality and morbidity after liver transplantation. In our transplant centre, among patients who underwent a liver transplantation between January 1989 and December 2000, 14 liver graft recipients (6.86%) developed de novo severe renal dysfunction as defined by a serum creatinine concentration above 200 micromol/L. Renal biopsy was performed in nine cases and evidenced histological lesions compatible with chronic nephrotoxicity related to calcineurin inhibitor treatment. For nine patients, we report the results of a prospective non-randomized study consisting of cyclosporine or tacrolimus withdrawal associated with administration of mycophenolate mofetil or azathioprine. Despite this therapeutic modification, we did not observe a significant renal function improvement but on the other hand, there was no graft rejection.

Renal failure after liver transplantation: outcome after calcineurin inhibitor withdrawal

Chronic nephrotoxicity is one of the most serious side-effects of calcineurin inhibitor treatment and a factor in mortality and morbidity after liver transplantation. In our transplant centre, among patients who underwent a liver transplantation between January 1989 and December 2000, 14 liver graft recipients (6.86%) developed de novo severe renal dysfunction as defined by a serum creatinine concentration above 200 micromol/L. Renal biopsy was performed in nine cases and evidenced histological lesions compatible with chronic nephrotoxicity related to calcineurin inhibitor treatment. For nine patients, we report the results of a prospective non-randomized study consisting of cyclosporine or tacrolimus withdrawal associated with administration of mycophenolate mofetil or azathioprine. Despite this therapeutic modification, we did not observe a significant renal function improvement but on the other hand, there was no graft rejection.

Skin cancer in organ transplant recipients: Epidemiology, pathogenesis, and management

In the United States more than 100,000 people are living with solid organ transplants. The intense immunosuppressive regimens necessary for prolonged survival of allografts significantly increase the rates of both internal and cutaneous malignancies in recipients of solid organ transplants. Skin cancer is the most common cancer in patients after transplantation. Because of the early onset and high tumor burden in transplant recipients, dermatologists have significant challenges in managing the treatment of these patients. This article describes the epidemiology and clinical presentation of skin cancer during posttransplantation immunosuppression, discusses pathogenic cofactors, and reviews the optimal management for mild and severe skin cancer in transplant recipients.

End-stage renal disease (ESRD) after orthotopic liver transplantation (OLTX) using calcineurin-based immunotherapy: risk of development and treatment

BACKGROUND

The calcineurin inhibitors cyclosporine and tacrolimus are both known to be nephrotoxic. Their use in orthotopic liver transplantation (OLTX) has dramatically improved success rates. Recently, however, we have had an increase of patients who are presenting after OLTX with end-stage renal disease (ESRD). This retrospective study examines the incidence and treatment of ESRD and chronic renal failure (CRF) in OLTX patients.

METHODS

Patients receiving an OLTX only from June 1985 through December of 1994 who survived 6 months postoperatively were studied (n=834). Our prospectively collected database was the source of information. Patients were divided into three groups: Controls, no CRF or ESRD, n=748; CRF, sustained serum creatinine >2.5 mg/dl, n=41; and ESRD, n=45. Groups were compared for preoperative laboratory variables, diagnosis, postoperative variables, survival, type of ESRD therapy, and survival from onset of ESRD.

RESULTS

At 13 years after OLTX, the incidence of severe renal dysfunction was 18.1% (CRF 8.6% and ESRD 9.5%). Compared with control patients, CRF and ESRD patients had higher preoperative serum creatinine levels, a greater percentage of patients with hepatorenal syndrome, higher percentage requirement for dialysis in the first 3 months postoperatively, and a higher 1-year serum creatinine. Multivariate stepwise logistic regression analysis using preoperative and postoperative variables identified that an increase of serum creatinine compared with average at 1 year, 3 months, and 4 weeks postoperatively were independent risk factors for the development of CRF or ESRD with odds ratios of 2.6, 2.2, and 1.6, respectively. Overall survival from the time of OLTX was not significantly different among groups, but by year 13, the survival of the patients who had ESRD was only 28.2% compared with 54.6% in the control group. Patients developing ESRD had a 6-year survival after onset of ESRD of 27% for the patients receiving hemodialysis versus 71.4% for the patients developing ESRD who subsequently received kidney transplants.

CONCLUSIONS

Patients who are more than 10 years post-OLTX have CRF and ESRD at a high rate. The development of ESRD decreases survival, particularly in those patients treated with dialysis only. Patients who develop ESRD have a higher preoperative and 1-year serum creatinine and are more likely to have hepatorenal syndrome. However, an increase of serum creatinine at various times postoperatively is more predictive of the development of CRF or ESRD. New strategies for long-term immunosuppression may be needed to decrease this complication.

Hypertension and renal dysfunction in long-term liver transplant recipients

1. A 10-year survival rate of 60% or greater after orthotopic liver transplantation (OLT) is expected. 2. Renal dysfunction is common after OLT. 3. Patients without early renal dysfunction after OLT are at low risk for long-term renal dysfunction. 4. Hypertension occurs in greater than 50% of long-term survivors. 5. Immunosuppressive protocols must be adjusted early to avoid long-term complications.

Calcineurin-inhibitor related nephrotoxicity- reversibility in paediatric liver transplant recipients

AIM

To study the efficacy of mycophenolate mofetil (MMF) as renal rescue in paediatric liver transplant recipients with calcineurin-inhibitor- (CI) related nephrotoxicity.

METHODS

Pediatric liver transplant recipients with stable graft function and a glomerular filtration rate (GFR) <80 ml/min/1.73 m2 were enrolled. MMF was introduced at 20 mg/kg/day and increased to 40 mg/kg/day after 1 week. CI dose was then reduced 6 weeks to achieve blood levels 25% of baseline. GFR was reassessed after 6 and 12 months.

RESULTS

Fourteen children with a median (range) interval from transplant of 57 (4-111) months were studied. Their median (range) GFR in ml/min/1.73 m2 increased from a baseline of 52 (31-71), to 69 (38-111) and 73 (35-98) at 6 and 12 months, respectively (P=0.00014). Side effects of MMF include leucopaenia in two and backache in one, two of whom discontinued MMF. Acute allograft rejection occurred in three children. All 14 are well with a median (range) follow-up of 24 (14-38) months from MMF introduction.

CONCLUSION

MMF allows the recovery of renal function from CI related nephrotoxicity in more than 70% of paediatric liver transplant recipients with renal impairment.

Replacement of calcineurin inhibitors with mycophenolate mofetil in liver-transplant patients with renal dysfunction: a randomised controlled study

BACKGROUND

Renal dysfunction is a major complication of long-term immunosuppressive therapy with calcineurin inhibitors (CNI) in liver-transplant recipients. We undertook a randomised study to assess the safety and efficacy of CNI withdrawal and replacement by mycophenolate mofetil.

METHODS

28 people who had had renal dysfunction attributable to suspected CNI toxicity after liver transplantation participated in the study. We replaced CNI with mycophenolate mofetil in a stepwise pattern in half the group (study patients); the other half (controls) stayed on CNI immunosuppression. Renal function, blood pressure, uric acid, and blood lipids were measured before and 6 months after study entry. Side-effects of medication and graft function were recorded throughout the study.

FINDINGS

At the end of the study, mean (SD) serum creatinine had fallen by 44.4 (48.7) micromol/L in study patients compared with 3.1 (14.3) micromol/L in controls; a mean difference of 41.3 micromol/L (95% CI 12.4-70.2). Moreover, systolic and diastolic blood pressure, and serum uric acid decreased significantly in the study group but not in the control group (mean [95% CI] between group differences 10.8 mm Hg [3.0-18.6], 5.0 mm Hg [0.9-9.2], and 83.1 micromol/L [12.7-153.6], respectively). There were no changes in cholesterol or triglyceride concentrations in either group. Side-effects were reported by eight of the study patients. Three reversible episodes of acute graft rejection occurred in study patients during mycophenolate mofetil monotherapy, whereas none occurred in the control group.

INTERPRETATION

Substitution of CNI by mycophenolate mofetil can improve renal function, blood pressure, and uric acid concentration of liver-transplant patients, but there is an increased rejection risk with mycophenolate mofetil monotherapy.

Use of mycophenolate mofetil as rescue therapy after pediatric liver transplantation

BACKGROUND

Mycophenolate mofetil (MMF) has been increasingly used after liver transplantation (LT) in adults. We report our preliminary experience with MMF as rescue therapy after pediatric LT.

METHODS

A total of 19 children received MMF for 21 indications. Median age at LT was 30 months (range 7-149). The median initial oral dose of MMF was 23 mg/kg/day (range 12-43) orally. Median follow-up after initiation of MMF therapy was 642 days (range 229-1606).

RESULTS

1) EFFICACY: MMF was indicated for rejection or insufficient immunosuppression in 16 cases, with normalization of both liver function tests and liver histology in 10 (62%). MMF was successfully used in one patient with post-LT immmune hepatitis and one patient with corticodependence. In three patients with renal function impairment, MMF allowed reduction of cyclosporine A or tacrolimus blood levels, without subsequent rejection. 2) Tolerance: Six patients (32%) experienced eight side effects, mainly gastrointestinal and hematological, which resolved after cessation of MMF in five cases and dose reduction in three. One case of posttransplant lymphoproliferative disease (PTLD) occurred under MMF therapy (5.2%). Four patients had EBV primary infection, while under MMF therapy, without subsequent PTLD. Three patients had CMV primary infection, and five CMV reactivation, under MMF therapy. Seven remained asymptomatic, and one presented with CMV enteritis.

CONCLUSIONS

These preliminary results suggest that MMF is an effective and safe immunosuppressant in pediatric LT recipients. Its use is hampered by frequent gastrointestinal and hematological side-effects. MMF does not seem to increase the risk of PTLD nor CMV disease.

Long-term care of the liver transplant recipient

Many liver transplant recipients are now reaching survival beyond 5 years from the liver transplant procedure, and many others are alive more than a decade from acquiring their new liver. Orthotopic liver transplant recipients enjoy the benefits of normal liver function, but a variety of metabolic and other medical problems often develop that require diagnosis and adequate management. These problems include hyperlipidemia, obesity, diabetes mellitus, renal disfunction, arterial hypertension, bone disease and neuropsychiatric syndromes. The gastroenterologist, internist, or local family physician is frequently called on to identify and treat these postoperative complications in conjunction with physicians at the transplant center.

A descriptive analysis of 290 liver transplant patient visits to an emergency department

OBJECTIVE

To provide a descriptive analysis of emergency department (ED) presentations and management of orthotopic liver transplant (OLT) patients.

METHODS

A retrospective chart review was performed of OLT patients presenting to the University of California at Los Angeles (UCLA) ED during 1995. The sole inclusion criterion was receiving an OLT within three years prior to the ED visit. Data describing chief complaint(s), history of present illness, physical findings, laboratory results, imaging studies, and final diagnoses were collected.

RESULTS

One hundred forty-three patients accounted for a total of 290 ED visits. The patients had a mean age of 37 years (range 3 months to 74 years) and presented at mean post-OLT duration of 9 months (range 2 weeks to 34 months). There were 660 presenting complaints, of which abdominal (39%), fever (17%), respiratory (13%), and neurologic (11%) symptoms were the most common. There were 478 final diagnoses, of which abdominal (27%), infectious (24%), and metabolic (11%) disorders were the most common. Eighty-four percent of ED visits resulted in extensive diagnostic testing and 69% resulted in hospitalization.

CONCLUSIONS

Serious illnesses with nonspecific presentations were frequently encountered in this study population. These factors resulted in a majority of the patients' undergoing extensive diagnostic evaluations and being hospitalized.

Improvement of acute and chronic renal dysfunction in liver transplant patients after substitution of calcineurin inhibitors by mycophenolate mofetil

BACKGROUND

Renal dysfunction caused by treatment with the calcineurin inhibitors (CNI) is a major problem in the long-term course after liver transplantation.

PATIENTS

In 22 liver graft recipients with renal dysfunction and stable graft function between 3 weeks and 12 years after transplantation, CNI were substituted by MMF at a final dose of 1.5-3 g/day between October 1996 and October 1998.

METHODS

In a prospective non-randomized study, the development of renal function, the side effects of MMF medication, and the stability of liver function were analyzed for a mean follow-up of 15 months. Results. (1) MMF was withdrawn in four patients for major side effects between 1 and 7 months after study entry; eight patients had minor side effects. (2) Six months after study entry, renal function had improved in 17 of the 22 study patients; mean serum creatinine +/-SD (micromol/L) was 201+/-77 at entry and 153+/-65 after 3 months (P<0.001). (3) Improvement occurred in 11 of 15 patients with creatinine elevation > or =12 months and in 6 of 6 patients with creatinine elevation < or =6 months. (4) One patient developed transient liver dysfunction and a second required retransplantation for progressive cholestasis but without signs of rejection.

CONCLUSIONS

In patients who undergo liver transplantation, substitution of CNI by MMF leads to improvement of acute as well as chronic renal dysfunction in most cases. Side effects of MMF may be limiting in some patients, and the immunological consequences remain to be studied.

Conversion of liver transplant recipients on cyclosporine with renal impairment to mycophenolate mofetil

The management of liver transplant recipients with renal function impairment remains controversial because cyclosporine withdrawal from triple immunosuppression regimens may be followed by graft rejection. A nonnephrotoxic and powerful immunosuppressant such as mycophenolate mofetil (MMF) could allow a reduction of cyclosporine dosage or its withdrawal and an improvement in renal function in these patients. Eleven patients with serum creatinine levels greater than 1.5 mg/dL, normal graft function, and a rejection-free period of at least 1 year started MMF at a dose of 2000 mg/d (reduced in case of adverse events) while cyclosporine dosage was slowly reduced. At last follow-up (63 +/- 5 weeks), 7 patients remained free of cyclosporine (6 of those patients are also free of steroids), 2 patients reduced their cyclosporine dose, and 2 patients developed mild acute rejection that responded to a switch to tacrolimus therapy. Serum creatinine and urea levels in the 7 patients free of cyclosporine decreased from 2.22 +/- 0.13 to 1.90 +/- 0.19 mg/dL (P =.05) and 0.95 +/- 0.10 to 0.60 +/- 0.10 g/L (P <.001), respectively. Creatinine clearance increased from 38.16 +/- 5.60 to 47.01 +/- 6. 76 mL/min (P =.005). Control of arterial hypertension also improved. Tolerance to MMF was good, but 6 patients required dose reductions, mainly because of asymptomatic anemia. In conclusion, in liver transplant recipients with stable graft function, MMF may allow cyclosporine dose reduction or discontinuation, thus improving renal function and the control of arterial hypertension. This change of treatment must be carefully monitored because of the frequent need for MMF dose reduction and the risk for rejection.

Mycophenolate mofetil monotherapy in stable liver transplant patients with cyclosporine-induced renal impairment: a preliminary report

BACKGROUND

Cyclosporine is the most common maintenance immunosuppressant in liver transplants patients, but it is often associated with nephrotoxicity.

METHODS

We evaluated the safety and efficacy of monotherapy with mycophenolate mofetil (1 g twice daily) in five stable liver transplant patients with cyclosporine-induced renal impairment despite reduction of cyclosporine to subtherapeutic levels. Follow-up was 8.4+/-2.4 (range: 6-12) months.

RESULTS

No major side effects have been observed to date. Serum creatinine levels were significantly reduced from a median of 201 micromol/L before to 142 micromol/L at 3 months after mycophenolate (P=0.04) and remained low at 6 months. New onset cellular rejection occurred in only one patient after 3 months on mycophenolate monotherapy, and it responded completely to an intravenous course of methylprednisolone.

CONCLUSIONS

Monotherapy with mycophenolate mofetil in a dose of 1 g twice daily seems to significantly improve cyclosporine-induced renal impairment in stable liver transplant patients without major side effects or significant risk of rejection.