Mycophenolate mofetil monotherapy in liver transplant recipients: a single center experience

Diarrhea in the pediatric solid organ transplantation recipient: A multidisciplinary approach to diagnosis and management

Diarrhea in the pediatric solid organ transplantation (SOT) recipient is a frequent complaint that is associated with significant morbidity and impaired quality of life. There are limited published data regarding the specific epidemiology, diagnostic evaluation, and treatment of diarrhea after SOT in children. Pediatric SOT recipients have an increased risk of developing diarrhea because of a generalized immunosuppressed state, epidemiologic exposures, and polypharmacy. There is a need to standardize the diagnostic evaluation of diarrhea in children after SOT to facilitate an accurate diagnosis and timely treatment. Herein, we review the available published data and propose a systematic, stepwise approach to the evaluation of diarrhea in this high-risk population, focusing on timely diagnosis of both infectious and non-infectious causes, in order to provide focused management. Prospective studies are needed to better assess the true prevalence, risk factors for, etiologies, and complications of diarrhea in pediatric SOT patients that will guide optimal management. Development of effective vaccines and antiviral therapies for enteric viruses may also contribute to improved outcomes.

Effect of cyclosporin and tacrolimus on kidney function in liver recipients

Introduction. Chronic renal failure is a significant issue regarding treatment of patients after liver transplantation. One of the factors determining the impaired renal function after liver transplantation is a long-term immunosuppressive therapy based on calcineurin inhibitors. The objective of the study was to evaluate the dynamics of renal function, depending on the use of various calcineurin inhibitors in the long-term postoperative period in liver recipients in real clinical practice.

Materials and methods. A retrospective analysis of the renal function in patients operated in the State Public Health Budget Institution “Scientific Research Institute – S.V. Ochapovsky Regional Clinic Hospital № 1”, Krasnodar Region, was carried out. This article describes dynamics of creatinine level and glomerular filtration rate (GFR) in patients before liver transplant, as well as 6 months, 1, 2 and 3 years after surgery. GFR was calculated using the CKD-EPI formula (Chronic Kidney Disease Epidemiology Collaboration). Statistical processing of the results was carried out using the Statistica 10 software package.

Results and discussion. Before transplantation, the level of creatinine in the blood plasma was 82.9±19.8 mmol/l, 6 months later a20.4% increase in creatinine was registered (p=0.004), 12, 24 and 36 months later – it increased by 24.8% (p=0.00001), 24.4% (p=0.0004), and 26.0% (p=0.0005), respectively. Both cyclosporine and tacrolimus caused an increase in the level of creatinine. Baseline GFR was 83.4±25.9, the reduction in GFR occurred in comparison with the baseline by 14.2% (p=0.0005), 18.8% (p=0.00001), 20.2% (p=0.00003), 22.6% % (p=0.00006) 6, 12, 24 and 36 months later, respectively. The degree of the decrease in GFR against the background of tacrolimus therapy did not differ significantly from that in case of cyclosporine. Verification of chronic kidney disease and the administration of statins were recorded in isolated cases.

Conclusions. In liver recipients, the level of creatinine rises and GFR decreases. Reduction of kidney function occurs against the background of both inhibitors of calcineurin, in connection with which it is necessary to increase the doctors’ alertness for early detection of a decrease in glomerular filtration rate with further verification of chronic kidney disease.

Intra-individual variability of mycophenolic acid concentration according to renal function in liver transplant recipients receiving mycophenolate monotherapy

BACKGROUNDS/AIMS

Mycophenolate mofetil (MMF) has wide inter- and intra-individual variability of mycophenolic acid (MPA) after liver transplantation (LT). On this study, we aimed to analyse the intra-individual variability of MPA concentration in stable adult LT recipients receiving MMF monotherapy and develop a method to determine the target level in the situation of wide intra-individual variability.

METHODS

This retrospective cross-sectional study included 30 LT recipients. All patients received MMF monotherapy at a dose of 500 mg twice daily for ≥2 years and were divided into two groups based on renal function. MPA concentration-associated values were presented as mean with standard deviation and coefficient of variation (CV).

RESULTS

The normal renal function group (n=15) showed a mean 12-hour MPA concentration of 2.5±0.5 µg/ml (range, 1.8±0.5 to 3.6±0.7 µg/ml) and a mean CV of 20.4±7.7% (range, 8.7% to 39.4%). In the renal dysfunction group (n=15), the 12-hour MPA concentration fluctuated more widely with a mean value of 3.7±0.9 µg/ml (range, 2.8±0.8 to 5.1±1.2 µg/ml) and a mean CV of 24.5±4.9% (range, 17.1% to 37.5%). The 12-hour MPA concentration was significantly higher in the renal dysfunction group, as compared to the normal renal function group (p=0.001); whereas, the CV was not significantly different between the two groups (p=0.093).

CONCLUSIONS

We determined the inter- and intra-individual variability of 12-hour MPA concentration after LT. The results suggested that therapeutic drug monitoring of MPA is necessary due to the inter-individual and intra-individual variability of MMF pharmacokinetics, especially in LT recipients with renal dysfunction.

Correlation between mycophenolic acid blood level and renal dysfunction in stable liver transplant recipients receiving mycophenolate monotherapy

PURPOSE

Mycophenolate mofetil (MMF) is frequently used after liver transplantation (OLT). Mycophenolic acid (MPA) metabolites are eliminated primarily via the kidneys. If renal function declines, clearance is significantly impaired. The aim of this study was to reveal the renal function-dependent changes of MPA level in stable adult OLT recipients receiving MMF monotherapy.

METHODS

Sixty-five OLT recipients were selected from our OLT database of >3500 cases. All had undergone MMF monotherapy with a daily MMF dose of 1000 mg or 1500 mg for more than 2 years, primarily because they could not tolerate calcineurin inhibitors. Their clinical profiles, including MPA therapeutic drug monitoring (TDM) and renal function, were analyzed as a cross-sectional study.

RESULTS

For the group treated with 1000 mg MMF (n = 40), the 12-hour MPA trough level was 1.20 ± 0.35 μg/mL with serum creatinine (Cr) level ≤1.4 mg/dL in 13 patients; it was 2.78 ± 1.19 μg/mL with Cr >1.4 mg/dL in 16 patients not undergoing hemodialysis and 3.83 ± 0.87 μg/mL in 11 patients undergoing hemodialysis (P < .001). For the group treated with 1500 mg MMF (n = 25), the MPA trough level was 2.23 ± 0.99 μg/mL with Cr ≤1.4 mg/dL in 6 patients; it was 2.81 ± 0.99 μg/mL with Cr >1.4 mg/dL in 18 patients not undergoing hemodialysis and 3.5 μg/mL in 1 patient undergoing hemodialysis (P = .21).

CONCLUSIONS

Considering the potential therapeutic range of MPA, the suggested MMF dosage for Korean adult OLT recipients requiring hemodialysis may be set around 1000 mg per day. We suggest adjusting the MMF dosage on an individualized basis according to the results of MPA TDM, particularly for patients with markedly impaired renal function.

Coeliac-like duodenal pathology in orthotopic liver transplant patients on mycophenolic acid therapy

AIMS

Diarrhoea following orthotopic liver transplantation (OLT) is a significant clinical problem associated with mycophenolic acid (MPA). The histological injury pattern associated with MPA in the large bowel is well documented in the literature; however, that in the duodenum is less extensively documented. The aim of this study was to investigate the histological spectrum of duodenal injury specifically in symptomatic OLT patients on MPA, and to compare this with the spectrum in patients with coeliac disease and in normal controls.

METHODS AND RESULTS

We reviewed our pathology database for all duodenal biopsies from patients on the OLT list over a period of 19 years. Medical records, anti-tissue transglutaminase IgA serology and histology were reviewed. Of the 667 patients who underwent endoscopy, 127 had duodenal biopsies (152 biopsies). Of these, 87.5% were normal. Sixteen showed abnormal histology, and seven (43.8%) of these were on MPA at the time of biopsy. Significant features included coeliac-like changes (shortened villi and increased intraepithelial lymphocyte counts), and novel findings included increased endocrine cell counts, apoptotic counts and lamina propria eosinophil counts in comparison with normal duodenal biopsies.

CONCLUSIONS

Pathologists should be aware of the features of MPA-associated duodenal injury, including coeliac-like changes and increased apoptotic counts. In those with abnormal histology, discontinuation or a reduction in the dose of MPA should be discussed.

Belatacept treatment for two yr after liver transplantation is not associated with operational tolerance

Belatacept was recently evaluated in liver transplantation (LT) in a phase II multicenter trial, which was terminated prematurely. Patients were more than two yr post-LT at the time. As high rates of spontaneous tolerance after LT have been reported and as belatacept has marked immunomodulatory effects, we decided to maintain the belatacept patients enrolled at our center (n = 4) on MMF monotherapy. All belatacept patients on MMF monotherapy developed graft dysfunction consistent with acute rejection after a mean period of 10.3 (7-14) wk. Patients were therefore switched to triple therapy with CNI, MMF, and corticosteroids. Graft dysfunction resolved within 1-3 wk after switch. At the time of belatacept discontinuation, mean eGFR was 105.1 mL/min/1.73 m² (92.1-118.9) in belatacept patients compared to 58 mL/min/1.73 m² (36.1-98.2) in controls (p = 0.022). One yr after the switch to CNI therapy, eGFR had declined by 27.4 mL (19.2-39.3; p = 0.008). Thus, LT patients treated with belatacept show superior kidney function that declines upon institution of CNIs. MMF monotherapy following withdrawal of belatacept is associated with a high incidence of graft dysfunction. Belatacept has no obvious immunomodulatory effects in LT recipients that would be sufficient to allow drug withdrawal with a high rate of success.

Clinical mycophenolic acid monitoring in liver transplant recipients

In liver transplantation, the efficacy of mycophenolate mofetil (MMF) has been confirmed in clinical trials and studies. However, therapeutic drug monitoring for mycophenolic acid (MPA) has not been fully accepted in liver transplantation as no long-term prospective study of concentration controlled vs fixed-dose prescribing of MMF has been done. This review addressed MPA measurement, pharmacokinetic variability and reasons of this variation, exposure related to acute rejection and MMF-associated side effects in liver transplant recipients. Limited sampling strategies to predict MPA area under the concentration-time curve have also been described, and the value of clinical use needs to be investigated in future. The published data suggested that a fixed-dosage MMF regimen might not be suitable and monitoring of MPA exposure seems helpful in various clinical settings of liver transplantation.

Mycophenolate mofetil monotherapy in liver transplantation: 5-year follow-up of a prospective randomized trial

BACKGROUND

Calcineurin inhibitors (CNIs) play the key role in immunosuppressive protocols yet are often associated with numerous side effects. Renal insufficiency, hypertension, hyperglycemia, and increased risk of secondary malignancy are major problems in short- and long-term follow-up of liver transplant patients. Mycophenolate mofetil (MMF) has proved to be a potent immunosuppressive agent free of the CNI-associated side effects.

PATIENTS AND METHODS

One hundred fifty patients who received liver transplantation at our institution (1998-2003) were prospectively randomized: 75 patients continued CNI standard therapy, 75 patients were switched to MMF monotherapy, and follow-up was 5 years. Incidence of rejection, renal complication, cardiovascular, neurological and gastrointestinal adverse effects, and diabetes and malignancy development was recorded. Graft biopsies were performed every 2 to 3 years.

RESULTS

No significant difference regarding the incidence of acute rejection was detected. A trend to higher rejection frequency was apparent in the MMF monotherapy group. Chronic rejection was absent; organ and patient survival were identical in the two groups. No significant difference occurred concerning the incidence of cardiovascular, gastrointestinal or neurological adverse effects, or the development of malignancies. Renal function improved significantly in patients with renal insufficiency when patients treated with CNI were switched to MMF monotherapy.

CONCLUSION

MMF monotherapy may serve as safe long-term immunosuppression after liver transplantation for a subgroup of patients. Especially for patients with renal insufficiency MMF offers immunosuppression without the risk of nephrotoxicity.

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.

Calcineurin-inhibitor minimization in liver transplant patients with calcineurin-inhibitor-related renal dysfunction: a meta-analysis

Background

Introduction of calcineurin-inhibitor (CNI) has made transplantation a miracle in the past century. However, the side effects of long-term use of CNI turn out to be one of the major challenges in the current century. Among these, renal dysfunction attracts more and more attention. Herein, we undertook a meta-analysis to evaluate the efficacy and safety of calcineurin-inhibitor (CNI) minimization protocols in liver transplant recipients with CNI-related renal dysfunction.

Methods

We included randomized trials with no year and language restriction. All data were analyzed using random effect model by Review Manager 5.0. The primary endpoints were glomerular filtration rate (GFR), serum creatinine level (sCr) and creatinine clearance rate (CrCl), and the secondary endpoints were acute rejection episodes, incidence of infection and patient survival at the end of follow-up.

Results

GFR was significantly improved in CNI minimization group than in routine CNI regimen group (Z = 5.45, P<0.00001; I² = 0%). Likely, sCr level was significantly lower in the CNI minimization group (Z = 2.84, P = 0.005; I² = 39%). However, CrCl was not significantly higher in the CNI minimization group (Z = 1.59, P = 0.11; I² = 0%). Both acute rejection episodes and patient survival were comparable between two groups (rejection: Z = 0.01, P = 0.99; I² = 0%; survival: Z = 0.28, P = 0.78; I² = 0%, respectively). However, current CNI minimization protocols may be related to a higher incidence of infections (Z = 3.06, P = 0.002; I² = 0%).

Conclusion

CNI minimization can preserve or even improve renal function in liver transplant patients with renal impairment, while sharing similar short term acute rejection rate and patient survival with routine CNI regimen.

Long-term, maintenance MMF monotherapy improves the fibrosis progression in liver transplant recipients with recurrent hepatitis C

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (LT) is universal. We designed a retrospective case-control study to evaluate the effect of mycophenolate mofetil (MMF) monotherapy in patients with recurrent hepatitis C. Fifteen patients with histologically proven hepatitis C recurrence after LT were switched from calcineurin inhibitors (CNIs) to MMF monotherapy because of impairment of kidney function and/or metabolic side effects, and treated for 48 months (MMF group). Fifteen well-matched LT recipients who continued to receive CNIs therapy over the same period served as control group. Demographics, clinical data, time after LT, and baseline liver biopsies were similar in the two groups. There was no worsening of hepatic fibrosis during the study in the MMF group [2.6 ± 1.5 (baseline) Ishak Units vs. 2.7 ± 1.8 (after 48 months of MMF treatment), P = 0.6]. In contrast, a significant increase in the fibrosis score [2 ± 1.1 (baseline) vs. 3.2 ± 1.7 (after 48 months of CNI treatment), P = 0.0002] was observed in the control group. The yearly fibrosis progression rate was of 0.05 ± 0.44 in the MMF group and 0.33 ± 0.24 in the CNI group (P = 0.04). MMF monotherapy is associated with a favourable effect on hepatic fibrosis progression in HCV liver transplant recipients.

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

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

Sustained renal response to mycophenolate mofetil and CNI taper promotes survival in liver transplant patients with CNI-related renal dysfunction

AIM

The aim of this trial was to evaluate the impact of conversion from a calcineurin-inhibitor (CNI)-based immunosuppressive regimen to mycophenolate mofetil (MMF) and reduced-dose CNI on long-term renal function and survival in a series of 63 liver transplant patients with CNI-induced renal dysfunction.

METHODS

CNI dosage was significantly tapered after introduction of 2,000 mg MMF per day. Renal function was assessed by determination of serum creatinine levels and calculated creatinine clearance (CCl). The impact of relevant clinical parameters on renal function and survival post-conversion was analyzed by univariate and multivariate analysis.

RESULTS

At 60 months post-conversion, mean creatinine level had significantly declined from 197.2±58.3 μmol/l at baseline to 160.0±76.5 μmol/l, and mean CCl has significantly increased from 38.4±13.4 ml/min at baseline to 47.9±21.1 ml/min (p<0.001), respectively. Forty-six patients (73.1%) demonstrated sustained renal response to modified immunosuppression. Full-dose MMF medication (p=0.006) and the early conversion (p=0.02) were identified as independent predictors of persistent renal function improvement. Sustained renal response to MMF plus reduced-dose CNI was identified as the most relevant independent promoter of long-term survival (hazard ratio 6.9). Five-year survival rate post-conversion was 93.9% in renal responders and 64.3% in renal non-responders (log rank<0.001).

CONCLUSIONS

Sustained renal response to MMF and CNI dose reduction promotes long-term survival in liver transplant patients with CNI-induced renal dysfunction.

The occurrence of diarrhea not related to the pharmacokinetics of MPA and its metabolites in liver transplant patients

PURPOSE

Mycophenolate mofetil (MMF) is a pro-drug that is hydrolyzed to release mycophenolic acid (MPA). Subsequently MPA is extensively metabolized to phenyl mycophenolic acid glucuronide (MPAG) and MPA acyl glucuronide (AcMPAG). It was presumed that the closest association is between plasma AcMPAG concentrations and the incidence of diarrhea. This study aimed to investigate the correlation between pharmacokinetics of MPA, MPAG, and AcMPAG and diarrhea in liver transplant recipients on MMF with tacrolimus.

METHODS

Sixty-seven patients receiving liver transplantation were included. The pharmacokinetics of MPA and its metabolites were monitored repeatedly in the early stage (within 2 weeks) and in the late stage after transplant. The plasma concentrations of MPA, MPAG, and AcMPAG were determined by the HPLC method.

RESULTS

Twenty-two patients (32.8%) suffered from episodes of diarrhea. Compared with the data from the early stage, AUC(0-12h) of MPA, MPAG, and AcMPAG increased significantly in both groups in the later stage. AUC(0-12h) of MPA, MPAG, and AcMPAG were not different significantly between the group with diarrhea and the group without diarrhea, either in the early stage or in the late stage (P > 0.05).

CONCLUSION

These results suggest that systemic exposures to MPA and its metabolites are not associated with the incidence of diarrhea in liver transplant recipients.

A clinical assessment of mycophenolate drug monitoring after liver transplantation

BACKGROUND

Recent findings have suggested the clinical utility of therapeutic drug monitoring (TDM) in patients treated with mycophenolate mofetil (MMF).

AIM

To assess whether routine mycophenolic acid (MPA) TDM is beneficial and how to utilize it.

METHODS

A series of short-term prospective studies on TDM for MPA and/or tacrolimus was performed at a large-volume center.

RESULTS

The 673 adult liver transplants were divided into four groups based on immunosuppressive regimens as tacrolimus monotherapy (n = 369), tacrolimus-MMF therapy (n = 270), MMF-minimal tacrolimus therapy (n = 17), and MMF monotherapy (n = 17). There was a significant difference of tacrolimus concentration between the groups receiving tacrolimus monotherapy and tacrolimus-MMF therapy during the first two yr (at two yr: 8.4 +/- 2.7 vs. 6.3 +/- 2.6 ng/mL; p < or = 0.002). MMF-minimal tacrolimus therapy and MMF monotherapy were applied after first three months and MPA levels ranged from 1.8 to 5.3 microg/mL. Correlation between MMF dosage and MPA concentration showed wide interindividual variations (n = 304, r(2) = 0.271, p < 0.001), in which r(2) was fluctuating from 0.056 to 0.213 according to the post-transplant period over five yr; wide intraindividual variation was also observed during the first two months (n = 12, r(2) < 0.2, p > 0.195). About 10% of patients were classified as poor MMF absorber and excluded from MMF usage. Mean MPA level leading to successful MMF monotherapy or MMF-minimal tacrolimus therapy was > or =1.0 microg/mL in 87% and >2.0 microg/mL in 56.5%.

CONCLUSION

MPA TDM-based MMF dosage adjustment enabled us to administer MMF more confidently than categorical dosing. MPA TDM appears to be a useful tool to cope with the wide pharmacokinetic variability of MMF after liver transplantation.

Efficacy and safety of mycophenolate mofetil monotherapy in liver transplant patients with renal failure induced by calcineurin inhibitors

OBJECTIVE

To assess the efficacy and safety of mycophenolate mofetil (MMF) monotherapy in liver transplant recipients with renal failure secondary to the use of calcineurin inhibitors (CNIs).

MATERIALS AND METHODS

Thirty-one patients on MMF monotherapy with creatinine levels >1.3 mg/dL, previously immunosuppressed with CNIs and MMF, were analyzed. Conversion was started in patients with no acute or chronic rejection episodes and stable liver chemistry. CNI doses were reduced by 25% every 2 to 3 months, or to 50% if the dose was lower than 1 mg/d of tacrolimus or 50 mg/d of cyclosporine. Different variables were recorded from the time that conversion to monotherapy was decided, on the discontinuation day of the calcineurin inhibitor, and during the follow-up.

RESULTS

Mean times from transplant to conversion ranged from 14 to 186 months. The minimum follow-up time in monotherapy was 12 months. Renal function improved at 6 months in 70% of cases and at 12 months in 69.6%. Patients with no renal function improvement maintained stable creatinine values. There were no rejection episodes, graft losses, or deaths. No leukopenia occurred, and triglyceride and uric acid values improved.

CONCLUSIONS

MMF monotherapy is a safe alternative in patients with posttransplant renal failure secondary to the use of CNIs. Renal function improvement was achieved in almost 70% of patients at 12 months, and creatinine values were maintained in all other patients. The risk of rejection due to the slow tapering of CNIs is minimum.

Mycophenolate mofetil monotherapy for severe side effects of calcineurin inhibitors following liver transplantation

Withdrawal of calcineurin inhibitors (CNI) followed by mycophenolate mofetil (MMF) monotherapy after liver transplantation (LT) remains controversial due to the increased risk of acute rejection and graft loss. The aim of the present study, performed in a large cohort of liver-transplanted patients with severe CNI-induced side effects, was to assess renal function recovery, and safety in terms of liver function, of complete CNI withdrawal and replacement by MMF monotherapy. Fifty-two patients treated with MMF monotherapy for CNI-induced toxicity were analyzed. Mean estimated glomerular filtration rate (eGFR) increased significantly during the period of MMF monotherapy, from 37 +/- 10 to 44.7 +/- 15 mL/min/1.73 m(2) at 6 months (p = 0.001) corresponding to a benefit of +17.4% in renal function. eGFR stabilized or improved in 86.5%, 81% and 79% of cases, and chronic renal dysfunction worsened in 13.5%, 19% and 21% of cases, at 6, 12 and 24 months after CNI withdrawal, respectively. Only two patients experienced acute rejection. MMF monotherapy may be efficient at reversing/stabilizing CRD, and appears relatively safe in terms of liver graft function in long-term liver-transplanted patients. However, clinicians must bear in mind the potential risk of rejection and graft loss, and should be very cautious in the management of such 'difficult-to-treat patients'.

Sirolimus-based immunosuppressive therapy in liver transplant recipient with tacrolimus-related chronic renal insufficiency

BACKGROUND

While providing potent immunosuppression for liver transplant recipients, calcineurin inhibitors (CNI) exhibit nephrotoxicity as a major side effect. The purpose of this study was to evaluate the safety and efficacy of conversion from CNI to sirolimus (SRL) among liver transplant recipients with CNI-induced chronic nephrotoxicity.

METHODS

Between January 2004 and June 2005, we performed conversion in 16 recipients after a median period of 8.5 months after liver transplantation. The indication for conversion was CNI-related nephrotoxicity with a serum creatinine (sCr) value >132.6 umol/L. Renal function was measured before and after conversion to SRL. Clinical and laboratory data related to the clinical course of the patients were recorded to investigate the safety and efficacy of conversion.

RESULTS

Sixteen patients were converted to SRL after developing nephrotoxicity. Their renal function improved gradually after conversion. The levels of sCr decreased significantly within the first 30 days (164.1 +/- 12.48 micromol/L to 130.1 +/- 5.573 micromol/L), and over the next 60 days after conversion (97.86 +/- 11.69 micromol/L to 90.7 +/- 8.95 micromol/L) (P < .01). Similarly, the mean glomerular filtration rate (GFR) increased significantly during the same period. Four recipients experienced hypercholesterolemia, 1 with ankle edema, and 1 with acute rejection. The median follow-up was 2.4 years. No patient discontinued SRL due to side effects. No patient needed dialysis or kidney transplantation during the study period.

CONCLUSIONS

SRL is a safe, effective replacement agent as primary immunosuppressive therapy following withdrawal of CNIs in liver transplant recipients with CNI-induced chronic nephrotoxicity.

Conversion to mycophenolate mofetil for modulating recurrent hepatitis C in liver transplant recipients

BACKGROUND

The aim of this study was to analyze the influence of cyclosporine A (CsA) taper in conjunction with mycophenolate mofetil (MMF) therapy on recurrent hepatitis C virus (HCV) in liver transplant patients.

PATIENTS AND METHODS

Nineteen liver recipients with serologically and morphologically confirmed recurrent HCV were included in this study. After MMF introduction up to a maximum dose of 2000 mg/day, CsA dose was significantly tapered. In the control group immunosuppression remained unchanged. Allograft function and morphology, viral loads, and renal function were analyzed continuously.

RESULTS

MMF treatment was well tolerated without risk of rejection. Allograft fibrosis progressed in 6 patients of the MMF group (66.6%) and none (0%) of the controls at 12-month biopsy (P=0.005). Moreover, aminotransferases and viral loads increased slightly in the MMF-treated patients. Renal function improved significantly (serum creatinine: 239.3+/-90.2 micromol/L vs. 175.8+/-46.0 micromol/L; P=0.008) in the treatment group, while deteriorating (serum creatinine: 156.8+/-44.6 micromol/L vs. 214.8+/-120.1 micromol/L; P=0.06) in the controls.

CONCLUSION

MMF introduction allows a safe CsA taper in HCV-positive liver transplant patients and results in significant improvement of renal function. However, there seems to be a risk of marked progression of HCV-induced allograft injury.

Clinical trial: switch to combined mycophenolate mofetil and minimal dose calcineurin inhibitor in stable liver transplant patients--assessment of renal and allograft function, cardiovascular risk factors and immune monitoring

BACKGROUND

Calcineurin inhibitor (CNI)-related nephrotoxicity significantly contributes to chronic renal failure after liver transplantation.

METHODS

In this prospective study, liver transplantation patients with renal dysfunction were randomized either to receive mycophenolate mofetil (MMF) followed by stepwise reduction of CNI with defined minimal CNI-trough levels (MMF group), or to continue their maintenance CNI dose (control group). Immune monitoring was performed in a subgroup of the patients.

RESULTS

In the MMF group (n = 50), renal function assessed by serum creatinine improved >10% in 62% of patients, was stable in 36% and deteriorated >10% in 2% after 12 months compared with baseline values. Mean serum creatinine levels (+/- s.d.) significantly decreased from 1.90 +/- 0.44 mg/dL to 1.61 +/- 0.39 mg/dL and the corresponding calculated glomerular filtration rate significantly increased from 38.8 +/- 9.6 mL/min/1.73 m(2) to 47.0 +/- 11.8 mL/min/1.73 m(2) over a 12-month follow-up period. Blood pressure and levels of liver enzymes significantly decreased. In the control group (n = 25), there were no significant changes with respect to the investigated parameters. The MMF group had significantly lower numbers of circulating cytotoxic T cells compared with the controls; whereas regulatory T cells significantly increased.

CONCLUSION

Combined MMF and minimal dose CNI therapy after liver transplantation is nephroprotective and may promote allograft tolerance.

Conversion to sirolimus-based immunosuppression in maintenance liver transplantation patients

Sirolimus (SRL) has been proposed to replace calcineurin inhibitors (CNI) in case of CNI-induced toxicity. The aim of this study was to evaluate the efficacy and safety of conversion from CNI to SRL in maintenance liver transplantation (LT) patients. Between 2002 and 2006, conversion was performed in 48 patients (17 female, 31 male; mean age 57 +/- 10 yr) after a median delay of 19.4 months (range 0.2-173 months) after LT. Indication for conversion was renal impairment (RI) (78%), CNI neurotoxicity (13%), or post-LT cancer (9%). Median follow-up was 22.6 +/- 11 months. Median SRL dosage and trough levels were 2.4 +/- 1.3 mg and 8.1 +/- 2.7 microg/L. Immunosuppression consisted of SRL alone (33%), or SRL + mycophenolate mofetil (MMF) (39%), SRL + prednisone (15%), SRL + CNI (4%), or SRL + MMF + prednisone (8%). Mean glomerular filtration rate (GFR) improved from 33 to 48 mL/minute in patients with severe RI (P = 0.022) and from 56 to 74 mL/minute in patients with moderate RI (P = 0.0001). After conversion, main complications were albuminuria (36%), hyperlipidemia (49%), dermatitis (14%), edema (14%), oral ulcers (12%), joint pain (4%), infection (2%), and pneumonia (2%). Acute rejection (AR) occurred in 17% of the patients. SRL was withdrawn in 17% of the patients. In conclusion, conversion from CNI to SRL is safe and is associated with significant renal function improvement.

Review article: medical management of the liver transplant recipient - a primer for non-transplant doctors

BACKGROUND

Survival 10 years after orthotopic liver transplantation now approaches 65%. Consequently, community doctors must manage the metabolic and neoplastic complications of orthotopic liver transplantation in an ageing population.

AIMS

To review common sources of morbidity and mortality in long-term orthotopic liver transplantation recipients, and to make evidence-based recommendations regarding their management.

METHODS

Pertinent studies and reviews were identified by literature search through PubMed. Where evidence-based recommendations could not be gleaned from the literature, expert opinion was obtained from syllabi of national meetings.

RESULTS

The two most common causes of morbidity and mortality in orthotopic liver transplantation recipients are atherosclerotic vascular disease and de novo malignancy. The pathogenesis of many complications begins before orthotopic liver transplantation, and many are potentially modifiable. Most complications, however, can be directly ascribed to immunosuppressive agents. Despite improvements in our understanding of the pathogenesis and epidemiology of the metabolic and neoplastic complications of orthotopic liver transplantation, remarkably few randomized-controlled studies exist to define their optimal management.

CONCLUSIONS

Orthotopic liver transplantation recipients experience and succumb to the same afflictions of old age as non-transplant patients, but with greater frequency and at an earlier age. Most recommendations regarding surveillance for, and treatment of, medical complications of orthotopic liver transplantation remain based upon expert opinion rather than evidence-based medicine.

Efficacy and safety of monotherapy with mycophenolate mofetil in liver transplantation

AIM

To analyze the efficacy and safety of mycophenolate mofetil (MMF) as monotherapy in liver transplant patients who have adverse effects associated with calcineurin inhibitors (CNIs).

PATIENTS AND METHODS

Seventeen patients, 13 men and four women, mean age 62 years, who received a liver transplant between 1998 and 2003 and initial immunosuppressive therapy with CNIs (10 tacrolimus and seven cyclosporine), were converted to monotherapy with MMF due to adverse events associated with CNIs: chronic renal failure in 16 patients (four with diabetes mellitus and seven with hypertension) and neurotoxicity in one patient. The mean time between transplant and starting monotherapy was 32 months (range: 18 to 70) and the mean follow-up time on monotherapy was 20 months (range: 8 to 39). MMF was introduced gradually at the same time as the CNIs were reduced.

RESULTS

There was a progressive decrease in creatinine during the initial months. Compared with baseline levels, the differences at 3 and 6 months of monotherapy were significant (P < .001), remaining so throughout the follow-up period. Renal function improved in 15 of 17 patients (88%) and normalized in 10 of 17 (60%). The patient with neurotoxicity due to CNI improved. One patient (6%) had moderate rejection that was corrected after reintroducing tacrolimus. In two patients it was necessary to suspend MMF, one due to gastrointestinal intolerance and the other due to severe myelotoxicity and Pneumocystis jiroveci infection. Other, minor adverse events were corrected by adjusting the dose: one herpes zoster, two diarrhea, and two anemia.

CONCLUSIONS

Monotherapy with MMF efficiently and safely corrected renal dysfunction associated with CNIs, with few side effects and a low incidence of rejection.

Switch to 1.5 grams MMF monotherapy for CNI-related toxicity in liver transplantation is safe and improves renal function, dyslipidemia, and hypertension

Although mycophenolate mofetil (MMF) monotherapy has been successfully used in liver transplant recipients suffering from calcineurin-inhibitor (CNI)-related chronic toxicity, still no consensus has been reached on its safety, efficacy and tolerability. We attempted the complete weaning off CNI in 42 individuals presenting chronic renal dysfunction and/or dyslipidemia and/or arterial hypertension and simultaneously introduced 1.5 gm/day MMF. CNI could be completely withdrawn in 41 cases. A total of 32 (75%) patients are currently on <or=1.5 gm/day of MMF. Mean follow-up from the introduction of MMF is 31.5 months and mean length of follow-up from the beginning of MMF monotherapy is 27.3 months. Renal function improved in 31/36 (89%) cases. Blood levels of cholesterol and triglycerides decreased in 13 of 17 (76%) and 15 of 17 (89%) patients, respectively. Arterial hypertension improved in 4 of 5 (80%) cases. A total of 8 patients showed a single episode of fluctuation of liver function tests during tapering off CNI. This feature was interpreted as an acute rejection (AR), based on the resolution of the clinical setting after escalation of MMF daily dose to 2 gm. A further patient developed a biopsy-proven AR insensitive to MMF adjustment, requiring reinstitution of the CNI dose. No deaths or major toxicity requiring MMF discontinuation occurred. In conclusion, low dose MMF monotherapy is safe, effective, and well tolerated.

Mycophenolate mofetil in liver transplantation ? is monotherapy safe?

Liver transplantation (LTX) today has become a routine procedure granting curative treatment for various hepatic diseases with excellent survival rates. Constant improvement of immuno-suppressive regimens has led to significant reduction of rejection frequency and increased safety in long-term management. Calcineurin-inhibitors play the key role in most immunosuppressive protocols providing strong T-cell suppression yet often associated with numerous side-effects. Increasing renal insufficiency as well as hypertension, hyperglycaemia, hyperuricaemia, and increased risk of secondary malignancy account for the major problems in short- and long-term follow-up of LTX patients. Mycophenolate mofetil (MMF) as a purine-synthesis inhibitor has proved to be a potent immunosuppressive agent largely free of the CI-associated side-effects. MMF therefore has been used to modulate immunosuppressive protocols in order to both increase efficacy and to reduce CI-related side-effects such as nephrotoxicity. In recent years, MMF-monotherapy protocols have been suggested for LTX patients with renal insufficiency. This review provides an overview on the current role of MMF in immunosuppressive protocols after LTX and evaluates innovative therapeutic concepts.

Immunosuppression based on mycophenolate mofetil in stable liver transplanted patients

AIM

To analyze our results with mycophenolate mofetil (MMF) in stable liver transplantation (LT) patients presenting with adverse events (AE) related to prolonged use of calcineurin inhibitors (CNI).

METHODS

Conversion to MMF was performed in 56 out of 323 LT patients from 91-02: 24 (43%) were converted to MMF in monotherapy and 32 (57%) to MMF+low doses of CNI. The indication for conversion was chronic renal insufficiency (CRI) in all patients. The mean time between AE and conversion was 38.7+/-30 months (r: 2-101 m). Post-conversion follow-up was 39+/-20 months (r: 3-72 m).

RESULTS

The calculated creatinine clearance (Crauckoft), improved significantly in all patients. In those converted to MMF, improvement was seen during the first 18 months for urea and during the first 6 months for creatinine. In patients converted to MMF+CNI, improvement was maintained throughout the conversion period for both urea and creatinine. Eleven (19.6%) patients underwent acute rejection (2 severe episodes in the MMF group and 1 death). Hypertension was present in 31 patients but only improved in 4 (7%). Dyslipemia was found in 12 and improved in 4 (7%). DM was present in 14 and improved in 1 (2%).

CONCLUSIONS

Conversion to MMF in monotherapy is useful in stable LT patients with CRI due to CNI, although this result is offset by more severe rejections. Therefore, for AE secondary to CNI, we propose an early conversion to MMF+low doses of CNI as a first step. If liver function remains stable and AEs persist or progress, conversion to MMF in monotherapy is recommended, as a second step, with close monitoring of the patient.

Chronic kidney disease post-liver transplantation

BACKGROUND

Renal disease is a recognized complication of orthotopic liver transplantation (OLT). We aimed to determine the incidence of all stages of chronic kidney disease (CKD), as defined in the Kidney Disease Outcomes Quality Initiative Guidelines. We also wanted to determine the risk factors for development of CKD and its impact on patient survival.

METHODS

All patients who underwent cadaveric OLT, from January 1993 until July 2004, were analysed. The glomerular filtration rate (GFR) was determined using the equation developed by the Modification of Diet in Renal Disease Study. Thirty potential risk factors were examined by univariate and multivariate ordinal logistic regression analysis. Kaplan-Meier survival analysis, the log-rank test and Cox regression analysis were performed to evaluate the survival data.

RESULTS

A total of 230 patients were included (107 males and 123 females) with a mean age of 47.7 years (4.5-70.35). Mean follow-up was 5.57 years (0.53-16.5). The following was the 10 year cumulative incidence for each stage of CKD: 0/1, 9.61%; 2, 53.71%; 3, 56.77%; 4, 6.11%; 5, 2.62%. Female gender, age, pre-OLT proteinuria, lower GFR from 1 year and higher creatinine from 6 months were associated with progression of CKD. The use of tacrolimus had a favourable impact. A GFR <30 ml/min, the need for re-transplantation and fulminant hepatic failure were all associated with reduced patient survival.

CONCLUSIONS

Moderate CKD was very prevalent. We identified the risk factors for progression of CKD and also that severe CKD was associated with reduced patient survival.

Indications of mycophenolate mofetil in liver transplantation

Mycophenolate mofetil (MMF) is approved for prophylaxis of acute rejection after kidney, heart, and liver transplantation as well as for pediatric patients after kidney transplantation. MMF, a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH), blocks de novo purine synthesis which leads to an effective inhibition of proliferation selectively in T and B lymphocytes, smooth muscle cells, and fibroblasts. MMF shows additional effects with inhibition of the expression of activating and adhesion molecules on the surface of lymphocytes. The beneficial safety profile with distinct side effects compared to calcineurin inhibitors (CNI) enable efficacious combination with ciclosporin or tacrolimus as de novo therapy after liver transplantation. Furthermore, recent studies show the possibility to reduce CNI induced toxicities by adding MMF to primary immunosuppression. MMF is also used to enable early steroid withdrawal after liver transplantation. MMF can increase efficacy of immunosuppressive therapy and thereby support the treatment of steroid resistant acute rejections, chronic rejections and chronic graft dysfunction.

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.

Diarrhea in liver transplant recipients: etiology and management

Diarrhea is common after liver transplantation (LT). The true incidence of diarrhea in liver transplant recipients is unknown but possibly ranges from 10% to 43% based on a few published studies in other solid organ and bone marrow transplantation. Infectious etiologies, including cytomegalovirus (CMV), Clostridium difficile, and occasional atypical intestinal infections, are the most common causes. Diarrhea is also a frequent side effect of immunosuppressive medications. To variable extents, mycophenolate mofetil (MMF), cyclosporine A (CSA), tacrolimus, and sirolimus are all known to be associated with diarrhea. Rarely, graft-versus-host disease (GVHD), lymphoproliferative disorder, de novo inflammatory bowel disease (IBD), or colon cancer may present as diarrhea. Flare-up of preexisting IBD is also not uncommon after LT. However, the cause of acute diarrhea remains unidentified in 1 of 3 patients. This review summarizes the literature and provides recommendations on the management of acute diarrhea after LT. Although our focus is on LT, the etiology and management recommendations apply to most transplant recipients.