Mycophenolate mofetil monotherapy in stable liver transplant recipients with progressive renal failure

Mycophenolate mofetil monotherapy in liver transplant recipients

INTRODUCTION

Complete conversion of calcineurin inhibitor (CNI) immunosuppressant therapy to non-nephrotoxic agents such as mycophenolate mofetil (MMF) is controversial, but may be safe in selected patients, although appropriate protocols and long-term benefits of conversion are not well reported.

METHODS

We analyzed all liver transplant (LT) recipients at our institution who were converted from CNI-based therapy to MMF monotherapy because of renal dysfunction (n = 23) and compared them with patients remaining on CNI-based therapy (n = 23). Renal function, rejection episodes, and markers of CNI-related comorbidities (lipid profile, blood pressure, and glycosylated hemoglobin) were noted.

RESULTS

Overall, serum creatinine (SCr) and calculated glomerular filtration rate improved on MMF monotherapy. This improvement was significant when compared with patients who remained on CNI-based therapy. Improvement was most pronounced in patients with milder renal dysfunction (SCr <2.2 mg/dL prior to conversion) (n = 14) with decrease in SCr from 1.63 ± 0.29 to 1.34 ± 0.26 mg/dL (p = 0.02) at last follow-up. Five patients on MMF monotherapy (21.7%) progressed to end-stage renal disease (ESRD), while only two (8.7%) had rejection episodes following conversion. Clinical markers of CNI-related comorbidities also improved. MMF monotherapy was well tolerated.

CONCLUSION

In summary, our data support the safety and efficacy of CNI to MMF monotherapy conversion.

Conversion from a calcineurin inhibitor to everolimus therapy in maintenance liver transplant recipients: a prospective, randomized, multicenter trial

Calcineurin inhibitors (CNIs) contribute to renal dysfunction following liver transplantation. This prospective, randomized, multicenter, 6-month study (with an additional 6 months of follow-up) evaluated whether everolimus with CNI reduction or discontinuation would improve renal function in maintenance liver transplant recipients experiencing CNI-related renal impairment. Patients started everolimus therapy with CNI reduction or discontinuation (n = 72) or continued receiving standard-exposure CNI (n = 73). At month 6, 80% of the patients who had converted to everolimus had discontinued the CNI. The mean change in creatinine clearance (CrCl) from baseline to month 6 was similar between groups (everolimus, 1.0 +/- 10.2 mL/minute; controls, 2.3 +/- 7.8 mL/minute; P = 0.46), so the primary study endpoint (8 mL/minute difference in the change in CrCl) was not achieved. Among patients who continued everolimus according to the protocol, the mean increase in CrCl was 2.1 (n = 53) and 3.8 mL/minute (n = 38) at months 6 and 12, respectively, versus 2.4 (n = 68) and 3.5 mL/minute in controls (n = 51). The high frequency of CNI dose reductions in controls (77% of the patients) and the relatively long mean time post-transplant (>3 years) likely contributed to the small difference in CrCl. Biopsy-proven acute rejection occurred in 1.4% of the patients in each group, with no graft losses. Study drug discontinuation was higher in everolimus-treated patients, and adverse events were more frequent. These data demonstrate that everolimus allows for discontinuation or a major reduction of CNI exposure in liver allograft recipients suffering CNI-related renal dysfunction without a loss of efficacy. Trials targeting earlier conversion post-transplantation are required to confirm the efficacy and safety of everolimus for improving renal function after liver transplantation.

Calcineurin inhibitor-sparing regimens in solid organ transplantation: focus on improving renal function and nephrotoxicity

BACKGROUND

The calcineurin inhibitors (CNIs), cyclosporine and tacrolimus, have had a revolutionary effect on the overall success of renal transplantation through reduction in early immunologic injury and acute rejection rates. However, the CNIs have a significant adverse impact on renal function and cardiovascular disease, and extended long-term graft survival has not been achieved. The recognition of these effects sparked interest in CNI-sparing strategies. Strategies to limit CNI exposure include CNI minimization, avoidance, and withdrawal. We sought to review the impact of CNI-sparing strategies in kidney, liver, and heart transplantation.

MATERIALS AND METHODS

A PubMed search 1966 to August 2006 was conducted to identify relevant research articles, and the references of these articles as well as the authors' personal files were reviewed.

RESULTS

Calcineurin inhibitor minimization using mycophenolate mofetil or sirolimus may be associated with a modest increase in creatinine clearance (CrCl) and a decrease in serum creatinine (SCr) in the short term. Despite improvement in CrCl or SCr, CNI nephrotoxicity and chronic allograft nephrotoxicity are progressive over time when CNI exposure is maintained. In kidney transplantation, the tubulo-interstitial and glomerular damage are irreversible. Mycophenolate mofetil may improve renal outcomes during CNI minimization more than sirolimus, and antibody induction may be effective to limit CNI exposure, but longer-term follow-up data are required. Use of sirolimus with mycophenolate mofetil or azathioprine to avoid CNI exposure de novo has improved glomerular filtration rate for at least two yr in most studies in kidney transplantation; however, experience is limited in liver and heart transplantation, and reports of delayed graft function and wound healing with sirolimus may have dampened enthusiasm for de novo use. Late CNI withdrawal has achieved variable results, possibly because withdrawal was attempted after the kidney damage was too extensive. Early CNI withdrawal, prior to significant graft damage, has generally improved CrCl and markers of fibrosis and decreased chronic allograft lesions, a finding also observed with sirolimus in most CNI avoidance studies. Successful withdrawal appears to be more effective than CNI minimization.

CONCLUSIONS

Calcineurin inhibitors are associated with significant nephrotoxicity and chronic kidney damage. Minimization is associated with a modest increase in renal function, but persistent damage is observed on biopsies as long as the CNIs are continued. Avoidance is hampered by lack of experience and possible sirolimus-induced side effects. CNI withdrawal may be the best option by delivering CNIs during the early period of immunologic graft injury and then converting them to less nephrotoxic agents before significant renal damage occurs.

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.

Mycophenolate mofetil monotherapy in liver transplantation

AIM

Calcineurin inhibitors (CI) are associated with significant morbidity in transplant recipients. The aim of this study was to evaluate the effectiveness and safety of mycophenolate mofetil (MMF) monotherapy in liver transplantation (LT).

METHODS

We analysed 32 patients (24 males, 8 female, of mean age 55.7 years) who underwent LT between 1994 and 2003. In 29 patients immunosuppressive therapy was cyclosporine; in three patients it was tacrolimus. Eleven patients were submitted for LT due to hepatitis B cirrhosis; eight for hepatitis C cirrhosis, six for alcoholic cirrhosis, and seven for other diseases. In these patients, MMF was added gradually, simultaneously reducing the dosage of CI up to complete withdrawal. We considered the efficacy (decrease in serum creatinine) and the incidence of complications (acute and chronic rejection, leukopenia, diarrhea).

RESULTS

Patients were converted to MMF after a median of 50 months after LT. MMF monotherapy was started after a median of 9 months in association with CI. Indications for switch to MMF monotherapy were adverse effects of CI (renal disfunction in 30 patients) and de novo tumoral evidence after LT in two patients. Median dosage of MMF was 750 mg twice daily (500-1500 mg). There was a statistically significant decrease in serum creatinine levels (2.02-1.7 mg/dL; P = .0001). Side effects were: leukopenia in five of 32 patients (15.6%), diarrhea in four of 32 patients (12.5%), and one acute rejection.

CONCLUSION

MMF monotherapy improved renal function and was not associated with a significant risk of allograft rejection. Side effects were mild with dose regimens up to 750 mg twice daily.

Predictors of improvement in renal function after calcineurin inhibitor withdrawal for post-liver transplant renal dysfunction

BACKGROUND

Renal dysfunction after liver transplantation is a major management problem. Predictors of improvement in renal dysfunction after calcineurin inhibitor therapy (CNI) withdrawal and replacement with either mycophenolate mofetil (MMF) or azathioprine (AZA) have not previously been examined.

METHODS

Retrospective analysis of 33 post-transplant patients with creatinine clearance (CrCl) below 50 mL/min who were changed from CNI to either MMF or AZA. Following CNI withdrawal patients were divided into two groups: those with improved CrCl after switching and those without, to identify the variables associated with improved renal function.

RESULTS

Variables associated with improved CrCl were: absence of hypertension or diabetes, shorter time between transplantation and switch, deterioration in CrCl in months prior to switch and treatment with MMF (compared with AZA).

CONCLUSIONS

Our findings suggest CNI withdrawal should be targeted to a subgroup of patients whose renal function is most likely to improve.

The use of mycophenolate mofetil in liver transplant recipients

Mycophenolate mofetil is an important drug in the modern immunosuppressive arsenal. Mycophenolate mofetil is the semisynthetic morpholinoethyl ester of mycophenolate acid. Mycophenolate acid prevents T and B cell proliferation by specifically inhibiting a purine pathway required for lymphocyte division. This paper extensively reviews the experience of mycophenolate mofetil use in liver transplant recipients. In randomised trials, mycophenolate mofetil decreased the rate of acute rejection after liver transplantation, without a significant increase of septic complications. However, so far, there are no data indicating that mycophenolate mofetil increases liver transplant patient or graft survivals. Mycophenolate mofetil is interesting because of its particular side effects profile, which is very different from the other immunosuppressants. The absence of mycophenolate mofetil nephrotoxicity is of specific interest in liver recipients with impairment of renal function. The monitoring of mycophenolate acid area under the concentration time curve might be interesting to limit side effects and provide better clinical efficacy but the exact role of mycophenolate acid monitoring in liver recipients has yet to be further evaluated in large series.