Efficacy of mycophenolate mofetil combined with very low-dose cyclosporine microemulsion in long-term liver-transplant patients with renal dysfunction

In Vitro and In Vivo Functional Viability, and Biocompatibility Evaluation of Bovine Serum Albumin-Ingrained Microemulsion: A Model Based on Sesame Oil as the Payload for Developing an Efficient Drug Delivery Platform

Combination of bovine serum albumin with microemulsions as constituting ingredient biopolymer has long been regarded an innovative method to address the surface functionalization and stability issues in the targeted payload deliveries, thereupon producing effectively modified microemulsions, which are superior in loading capacity, transitional and shelf-stability, as well as site-directed/site-preferred delivery, has become a favored option. The current study aimed to develop an efficient, suitable and functional microemulsion system encapsulating sesame oil (SO) as a model payload towards developing an efficient delivery platform. UV-VIS, FT-IR, and FE-SEM were used to characterize, and analyze the developed carrier. Physicochemical properties assessments of the microemulsion by dynamic light scattering size distributions, zeta-potential, and electron micrographic analyses were performed. The mechanical properties for rheological behavior were also studied. The HFF-2 cell line and hemolysis assays were conducted to ascertain the cell viability, and in vitro biocompatibility. The in vivo toxicity was determined based on a predicted median lethal dose (LD₅₀) model, wherein the liver enzymes' functions were also tested to assess and confirm the predicted toxicity.

Kidney disease in non-kidney solid organ transplantation

Kidney disease after non-kidney solid organ transplantation (NKSOT) is a common post-transplant complication associated with deleterious outcomes. Kidney disease, both acute kidney injury and chronic kidney disease (CKD) alike, emanates from multifactorial, summative pre-, peri- and post-transplant events. Several factors leading to kidney disease are shared amongst solid organ transplantation in addition to distinct mechanisms unique to individual transplant types. The aim of this review is to summarize the current literature describing kidney disease in NKSOT. We conducted a narrative review of pertinent studies on the subject, limiting our search to full text studies in the English language. Kidney disease after NKSOT is prevalent, particularly in intestinal and lung transplantation. Management strategies in the peri-operative and post-transplant periods including proteinuria management, calcineurin-inhibitor minimization/ sparing approaches, and nephrology referral can counteract CKD progression and/or aid in subsequent kidney after solid organ transplantation. Kidney disease after NKSOT is an important consideration in organ allocation practices, ethics of transplantation. Kidney disease after SOT is an incipient condition demanding further inquiry. While some truths have been revealed about this chronic disease, as we have aimed to describe in this review, continued multidisciplinary efforts are needed more than ever to combat this threat to patient and allograft survival.

[Kidney failure after liver transplantation]

One third of cirrhotic patients present impaired kidney function. It has multifactorial causes and has a harmful effect on patients' morbi-mortality before and after liver transplant. Kidney function does not improve in all patients after liver transplantation and liver-transplant recipients are at high risk of developing chronic kidney disease. Causes for renal dysfunction can be divided in three groups: preoperative, peroperative and postoperative factors. To date, there is no consensus for the modality of evaluation the risk for chronic kidney disease after liver transplantation, and for its prevention. In the present review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease to determine a risk stratification for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this setting, and highlight the indications of combined liver-kidney transplantation.

Kidney disease in children with heart or liver transplant

Over the past few decades, there has been increasing recognition of kidney disease in children with non-kidney solid organ transplantation. The risk of kidney disease in children undergoing heart or liver transplantation is higher than the general population as the underlying disease and its associated management may directly impair kidney function. Both heart and liver failures contribute to hypoperfusion and kidney ischemia before patients reach the point of transplant. The transplant surgery itself can often be complicated by acute kidney injury (AKI), which may be further exacerbated by a complicated postoperative course. In the short- and long-term post-transplant period, these children are at risk of acute illness, exposed to nephrotoxic medications, and susceptible to rare but severe infections and immunologic insults that may contribute to AKI and chronic kidney disease (CKD). In some, CKD can progress to kidney failure with replacement therapy (KFRT). CKD and KFRT are associated with increased morbidity and mortality in this patient population. Therefore, it is critical to monitor for and recognize the risk factors for kidney injury in this population and mitigate these risks. In this paper, the authors provide an overview of kidney disease pertaining to heart and liver transplantation in children with guidance on monitoring, diagnosis, prevention, and management.

Kidney Failure after Liver Transplantation

One-third of patients with cirrhosis present kidney failure (AKI and CKD). It has multifactorial causes and a harmful effect on morbidity and mortality before and after liver transplantation. Kidney function does not improve in all patients after liver transplantation, and liver transplant recipients are at a high risk of developing chronic kidney disease. The causes of renal dysfunction can be divided into three groups: pre-operative, perioperative and post-operative factors. To date, there is no consensus on the modality to evaluate the risk of chronic kidney disease after liver transplantation, or for its prevention. In this narrative review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease in order to establish a risk categorization for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this context, and highlight the indications of combined liver–kidney transplantation.

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.

Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study

Acute kidney injury (AKI) is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT) and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage). Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538) and 6.3% (34/538) required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m² [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.32–4.55], serum albumin <3.5 mg/dl (OR 1.76, 95%CI 1.05–2.94), MELD (model for end-stage liver disease) score >20 (OR 2.01, 95%CI 1.17–3.44), operation time >600 min (OR 1.81, 95%CI 1.07–3.06), warm ischemic time >40 min (OR 2.61, 95%CI 1.55–4.38), postreperfusion syndrome (OR 2.96, 95%CI 1.55–4.38), mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01–2.70), cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84–8.64), blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28–7.21), and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14–3.06). Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia and postreperfusion syndrome would decrease postoperative AKI in LDLT.

Intractable and dramatic diarrhea in liver transplantation recipient with vasoactive intestinal peptide-producing tumor after split liver transplantation: a case report

Diarrhea after liver transplantation is a common complication. Vasoactive intestinal peptide-producing tumor (VIPoma) is a rare cause of watery diarrhea; 80% of such tumors occur in the pancreas, but it is rare in liver. Hypersecretion of vasoactive intestinal polypeptide can stimulate intestinal water and electrolyte secretion, and patients with VIPoma present with watery diarrhea, hypokalemia, and dehydration. Here we report on a 50-year-old man who presented with a 7-month history of watery diarrhea. He had undergone an orthotopic split-liver transplantation for hepatocellular carcinoma in November 2011. Two months after the liver transplantation, he presented with watery diarrhea, dehydration, and hypokalemia. Antibiotics, immunosuppressive drugs modification, antidiarrheal agents, antispasmodics, adsorbents, and fasting were alternately used to control the diarrhea, but his symptoms remained unchanged. A chromogranin examination, a marker of pancreatic neuroendocrine neoplasm, was positive in the third month of the diarrhea history and VIPoma was considered. Treatment with somatostatin immediately controlled the diarrhea, but the primary lesion could not be identified even after corresponding examinations were completed. In the ninth month of diarrhea, a 1 × 1-cm lesion was detected in the right liver by ultrasonography. Radiofrequency ablation was performed, and the diarrhea stopped. Seventeen months later, the chromogranin level decreased to normal and the patient was asymptomatic. Neither the recipient sharing the other liver portion nor the donor presented with any symptoms, so we wondered how the tumor occurred. It is possible that a small VIPoma lesion existed in the liver donor before the transplantation, and that the immunosuppressive drugs induced tumor development.

Effect of low-dose tacrolimus with mycophenolate mofetil on renal function following liver transplantation

AIM: To determine whether low-dose tacrolimus (TAC) combined with mycophenolate mofetil (MMF) is a safe approach to decrease the incidence of chronic kidney disease (CKD) in liver transplantation (LT) recipients.

METHODS: We analyzed the medical records of 689 patients who underwent LT between March 1999 and December 2012 in a single Chinese center. Immunosuppression was initiated with a calcineurin inhibitor (TAC or CSA) and prednisone with or without MMF. CKD is defined by the glomerular filtration rate (GFR), estimated by an abbreviated Modification of Diet in Renal Disease formula, < 60 mL/min per 1.73 m² for at least 3 consecutive months after LT. Individuals with TAC trough concentrations ≤ 8 ng/mL at 3 mo after LT were defined as the low-dose group. The incidence of CKD within 5 years was compared between the TAC group and the CSA group, as well as between four subgroups (low-dose and high-dose TAC groups with or without MMF).

RESULTS: No difference regarding the occurrence of pre-LT renal dysfunction or that of post-LT rejection was found between the TAC and CSA groups or between the four subgroups. With a definition of GFR < 60 mL/min per 1.73 m², the overall incidence of CKD was significantly higher in the CSA group than in the TAC group. The incidence of CKD in the low-dose TAC + MMF group (7.7%) was significantly lower than that observed in the low-dose TAC group (15.9%), high-dose TAC group (24.6%) and high-dose TAC + MMF group (18.5%). The cumulative 1-, 3- and 5-year incidence rates of CKD were 12.7%, 14.5% and 16.7%, respectively. The cumulative 5-year survival rates were 61.7% and 82.2% in patients with or without CKD, respectively.

CONCLUSION: In LT patients, the choice of immunosuppressive therapy appears to affect renal function and patient survival.

Cyclosporine A for the treatment of refractory nephrotic syndrome with renal dysfunction

Cyclosporine A (CsA) is an immunosuppressant agent and is utilized as a second-line drug therapy for refractory nephrotic syndrome (RNS). In general, the use of CsA is strictly controlled in patients with an estimated glomerular filtration rate (eGFR) <30–40 ml/min/1.73 m², and little is known about the safety and efficacy of CsA treatment in patients with RNS complicated by renal dysfunction. In the present study, the clinical data of 10 patients with RNS and renal dysfunction, who received CsA treatment between 2000 and 2009 in the Kidney Institute of PLA, were reviewed retrospectively. Pathologically, these patients included six cases with minimal change, two cases of diffuse mesangial proliferation and two cases of focal segmental glomerulosclerosis. Six months subsequent to the initiation of the CsA treatment, six patients achieved complete remission, two patients achieved remarkable remission and two patients achieved partial remission. Renal function was improved in all patients as represented by the improvement in the eGFR (28.6±3.8 ml/min/1.73 m² prior to treatment versus 99.3±21.9 ml/min/1.73 m² 6 months subsequent to treatment). Few adverse CsA-related events were observed. These results suggest that renal dysfunction is not an absolute contraindication for CsA treatment in patients with RNS. The use of CsA is safe and efficacious and may, in certain cases, improve renal function in patients with RNS and renal impairment.

Calcineurin inhibitors in liver transplantation - still champions or threatened by serious competitors?

Current strategies for immunosuppression in liver transplant (LT) recipients include the design of protocols targeting a more individualized approach to reduce risk factors such as renal failure, cardiovascular complications and malignancies. Renal injury in LT recipients may be often multifactorial and is associated with increased risk of post-transplant morbidity and mortality. The quest for low toxicity immunosuppressive regimens has been challenging and resulted in CNI minimization protocols or CNI withdrawal and conversion to mycophenolate mofetil (MMF) and/or mammalian target of rapamycin inhibitor-based immunosuppressive regimens. Use of antibody induction to delay CNI administration may be an option in particular in immunocompromized, critically ill patients with high MELD scores. Protocols including MMF introduction and concomitant CNI minimization have the potential to recover renal function even in the medium and long term after LT. We review on hot topics in the prevention and management of acute and chronic renal injury in LT patients. For this purpose, we present and critically discuss results from immunosuppressive studies published in the current literature or presented at recent LT meetings.

Effects of mycophenolate mofetil introduction in liver transplant patients: results from an observational, non-interventional, multicenter study (LOBSTER)

The benefits of calcineurin inhibitor (CNI)-sparing regimens on renal function following liver transplantation (LT) have been demonstrated in clinical studies. This observational study assessed the real-life effects of mycophenolate mofetil (MMF) introduction in LT patients. Four hundred and ninety-seven patients in whom MMF was introduced according to local standards or clinical considerations were entered. Patients were grouped by time between transplantation and start of MMF (start of study): Group A (n = 263): ≤6 d; Group B (n = 64): >6 d to ≤1 month; Group C (n = 74): >1 month to ≤1 yr; and Group D (n = 96): >1 yr. CNI sparing occurred in all groups, particularly in Groups C and D. Mean MMF doses at 12 months were 1202.7, 1363.5, 1504.7, and 1578.1 mg/d, respectively, in Groups A-D. At introduction of MMF, median glomerular filtration rate was 73.3, 81.7, 62.7, and 53.7 mL/min/1.73 m(2) in Groups A-D. At 12 months, this decreased to 66 mL/min/1.73 m(2) in Groups A and B, remained stable in Group C, and increased in Group D (64.8 mL/min/1.73 m(2) ). Serious adverse drug reactions were lowest in Group D. In conclusion, MMF with a subsequent decrease in CNI was well tolerated and improved renal function even years after transplantation. A more forceful MMF dosing strategy with greater CNI sparing may further improve renal function.

Pharmacokinetics of free mycophenolic acid and limited sampling strategy for the estimation of area under the curve in liver transplant patients

Mycophenolate Mofetil (MMF) is widely used in preventing acute rejection in liver transplantation. Only free MPA (fMPA) can exert the pharmacological effect. In this study, we aimed to develop the new model which could be best fit to predict the fMPA area under the plasma concentration-time curve (AUC) by limited sampling strategy (LSS) in Chinese liver transplant patients. Fifty patients received MMF with the combination of tacrolimus. Free MPA concentrations were determined around day 7. Optimal subset regression analysis was used to establish the models for estimated fMPA AUC(0-12h). Three excellent better models were validated by Bootstrap analysis. Twenty-four models including four blood time point samplings were established. For the selected four models, 100% were successful and were not significantly different from the original dataset by Bootstrap analysis. The best model for prediction of fMPA AUC(0-12h) was by using C(1h), C(2h), C(4h) and C(6h). This model showed the minimal mean prediction error and the minimal mean absolute prediction error. In conclusion, the models for estimation of the fMPA AUC(0-12h) were established in liver transplant recipients and the best model for prediction of fMPA AUC was: estimated fMPA AUC=34.2+1.12C(1h)+1.29C(2h)+2.28C(4h)+3.95C(6h).

Prophylaxis of chronic kidney disease after liver transplantation - experience from west China

AIM: To evaluate the prophylaxis of chronic kidney disease (CKD) after liver transplantation (LT) with low-dose calcineurin inhibitor (CNI) and mycophenolate mofetil (MMF).

METHODS: From March 1999 to December 2009, a total of 572 patients (478 males and 94 females) underwent LT enrolled in the study. Initial immunosuppression was by triple-drug regimens that included a CNI, MMF, and prednisone. The initial dose of CNI was 0.05-0.10 mg/kg per day for tacrolimus (TAC) and 5-10 mg/kg per d for cyclosporine A (CSA) respectively, and was gradually reduced based on a stable graft function. The serum trough level of CNI was 6-8 ng/mL for TAC and 120-150 ng/mL for CSA 3-mo post-operation, 4-6 ng/mL for TAC and 80-120 ng/mL for CSA 1-year after transplantation was expected with stable liver function. MMF was personalized between 1.0-1.5 g/d. Glomerular filtration rate (GFR) was estimated by an abbreviated Modification of Diet in Renal Disease formula. Risk factors of CKD were examined by univariate and multivariate logistic regression.

RESULTS: With a definition of GFR < 60 mL/min per 1.73 m², the incidence of CKD was 17.3% 5-year after LT. There were 68.3% (293 of 429 cases) patients managed to control their TAC trough concentrations within 8 ng/mL and 58.0% (83 of 143 cases) patients’ CSA trough concentrations within 150 ng/mL. Of the 450 recipients followed-up over 1 year, 55.5% (183 of 330 cases) of which were treated with TAC had a trough concentration ≤ 6 ng/mL while 65.8% (79 of 120 cases) of which were treated with CSA had a concentration ≤ 120 ng/mL. The incidence of CKD in the groups of lower CNI trough concentrations was significantly lower than the groups with CNI concentrations above the ideal range. Patients with CKD had much higher CNI trough concentrations than that of patients without CKD. MMF was adopted in 359 patients (62.8%). Patients administrated with MMF had a relatively low CNI trough concentrations but with no significant difference. The graft function remained stable during follow-up. No difference was found between different groups of CNI trough concentrations. Pre-LT renal dysfunction, ages, acute kidney injury, high blood trough concentrations of CNI in 3 mo (TAC > 8 ng/mL, CSA > 150 ng/mL) and hypertension after operation were associated with CKD progression, while male gender and adoption of MMF were protection factors.

CONCLUSION: Low dose of CNI combined with MMF managed to prevent CKD after LT with stable graft function.

Long-term outcomes of calcineurin inhibitor withdrawal for post-liver transplant renal dysfunction

BACKGROUND

It has become common practice to withdraw or reduce calcineurin inhibitors (CNI) in patients with renal dysfunction after liver transplantation; however, little is known about the long-term outcome of this strategy. This study investigates the long-term results of CNI withdrawal for post-liver transplant renal dysfunction and examines for factors that predict a significant improvement in renal function.

METHODS

A retrospective database review was performed to examine outcomes in patients with CNI withdrawn for chronic renal impairment. Univariate analyses were used to identify predictors of an improvement in creatinine clearance (CrC).

RESULTS

Sixty patients (44 males) were included. Of these, 82% of patients were switched to mycophenolate mofetil and 18% azathioprine. Median follow-up after CNI withdrawal was 48 (range 3-72) months. Postwithdrawal, there was an initial improvement in CrCl (mean 5.5 mL), which remained above baseline levels at 6 years. Acute cellular rejection developed in six patients (10%), but there was no rejection-associated graft loss. A shorter time from transplantation to conversion was associated with greatest improvement in CrCI.

CONCLUSIONS

CNI withdrawal is associated with a significant initial improvement and then arrest in long-term decline of renal function. Rejection in this setting is uncommon. The greatest benefit is seen in patients switched within the early years after transplantation.

Management of renal dysfunction in patients receiving a liver transplant

Renal dysfunction is a frequent complication in patients with endstage liver disease awaiting orthotopic liver transplantation. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, common causes of acute kidney injury include prerenal azotemia and acute tubular necrosis in this population. Management involves hemodynamic support, renal replacement therapy, and mitigation of risk factors. Renal dysfunction in a cirrhotic patient usually implies a poor prognosis in the absence of liver transplantation. An important issue is the frequent need for kidney, in addition to liver, transplantation if renal insufficiency has been persistent in a decompensated cirrhotic.

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.

Basiliximab induction and delayed calcineurin inhibitor initiation in liver transplant recipients with renal insufficiency

BACKGROUND

Renal insufficiency (RI) is common after liver transplantation (LT) and may worsen due to calcineurin inhibitor (CNI) use. We compared LT outcomes using basiliximab induction and delayed CNI initiation to controls with a standard CNI regimen in patients with peri-LT RI.

METHODS

All adults transplanted January 2004 to December 2007 with peri-LT RI (hemodialysis or creatinine ≥1.5 within 1 week of LT) were included in a retrospective nonrandomized cohort. Outcomes including 30-day and 1-year patient and graft survival and renal function were compared between basiliximab and control groups.

RESULTS

Two hundred twenty-nine patients (102 basiliximab, 127 controls) were analyzed, mean age 54 years, 72% men, 54% with hepatitis C virus. Mean model for end-stage liver disease (28.2 vs. 20.0; P<0.001) and creatinine (1.9 vs. 1.6; P=0.001) were higher and more patients were on hemodialysis at LT (29% vs. 6%; P<0.001) in the basiliximab group. 30-day patient (99% vs. 97%; P=0.26) and graft survival (98% vs. 95%; P=0.17), 1-year patient (87% vs. 87%; P=0.89) and graft survival (86% vs. 82%; P=0.37), mean creatinine at 1-year (1.5 vs. 1.5 mg/dL; P=0.82), and treated acute rejection (6% vs. 6%; P=0.90) were similar between basiliximab and control groups, respectively. In multivariable logistic regression, basiliximab was not significantly associated with 30-day (odds ratio, 0.10; P=0.11) or 1-year (odds ratio, 0.97; P=0.94) survival, controlling for age, previous LT, model for end-stage liver disease, and hepatitis C virus.

CONCLUSIONS

Basiliximab induction resulted in 30-day and 1-year patient, graft and renal outcomes comparable with a control group receiving standard CNI-based immunosuppression. Antibody induction with delayed CNI should be further studied prospectively.

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.

Improvement of renal function after conversion to mycophenolate mofetil combined with low-level calcineurin inhibitor in liver transplant recipients with chronic renal dysfunction

INTRODUCTION

Calcineurin inhibitors (CNI) are the main pathogenic factors for renal dysfunction in solid organ transplant recipients. Introduction of non-nephrotoxic immunosuppressive drugs, such as mycophenolate mofetil (MMF), may allow discontinuation or reduction of CNI treatment, thereby improving renal function. The aim of this study was to assess the feasibility, efficacy and safety of MMF introduction and CNI dosage reduction in the maintenance immunosuppressive protocol to improve renal function in liver transplant recipients with chronic renal dysfunction.

PATIENTS AND METHODS

We prospectively included 88 liver transplant recipients including 74 men and an overall mean age of 58.8 +/- 10.3 years who all displayed chronic renal dysfunction (creatinine >1.4 mg/dL) and proteinuria <1 g/d. They were subdivided into 3 groups according to the basal creatinine value 1.4-1.7 mg/dL (group I; n = 41); 1.8-2.0 mg/dL (group II; n = 28); and >2 mg/dL (group III; n = 19). MMF was initiated at 1.5-2.0 g/d. Reduction of tacrolimus or cyclosporine dosage was performed to achieve respective target trough levels of <5 ng/mL or <50 ng/mL. We performed periodic determinations of arterial pressure, liver function tests, serum creatinine, blood cells count, CNI levels, and proteinuria.

RESULTS

Creatinine values after conversion were 1.4 +/- 0.5 mg/dL in the overall group. Improvement of renal function was more frequent among groups I (80.4%) and II (92.8%) versus III (73.6%). Normalization of creatinine values was more frequent in group I (68.2%) with respect to cohorts II (21.4%) and III (10.5%). Rejection was not detected.

CONCLUSION

Application of an immunosuppressive protocol with MMF and low-level CNI in liver transplant recipients with chronic renal dysfunction was associated with improvement or normalization of creatinine, without an increased risk of rejection. Early conversion is needed to achieve the best results.

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.

Management of renal dysfunction in the liver transplant recipient

PURPOSE OF REVIEW

Acute and chronic kidney injury following orthotopic liver transplantation (OLT) is associated with increased morbidity and mortality. With the increasing longevity of liver transplant recipients, chronic kidney disease (CKD) has become an increasingly prevalent complication among long-term survivors. This article provides an overview of the literature on suggested risk factors for acute and CKD following OLT and a discussion of an approach to their medical management.

RECENT FINDINGS

In OLT candidates with pretransplant renal dysfunction, the use of interleukin-2 receptor blockers or antithymocyte globulin induction therapy in conjunction with delayed introduction of calcineurin inhibitors may preserve early renal function. In long-term stable OLT recipients with established calcineurin inhibitor nephrotoxicity, calcineurin inhibitor minimization or withdrawal protocols may halt or ameliorate renal dysfunction without compromising patient and graft survival. However, large-scale, multicenter, randomized controlled trials are still needed.

SUMMARY

The occurrence of acute kidney injury is common immediately after OLT, whereas the incidence of CKD and end-stage renal disease increases with time. Identifying patients at risk for acute kidney injury and CKD following OLT and early implementation of measures to preserve, halt, or ameliorate the progression of renal dysfunction should be an integral part in the management of OLT recipients.

Pharmacokinetics of mycophenolic acid and its glucuronide metabolites in stable adult liver transplant recipients with renal dysfunction on a low-dose calcineurin inhibitor regimen and mycophenolate mofetil

Low-dose calcineurin inhibitors (CNIs) in combination with a fixed dose (2 g/d) of mycophenolate mofetil (MMF) are a strategy to minimize exposure to cyclosporine (CSA) or tacrolimus (TAC) and thus reduce CNI-related side effects. This study compared the pharmacokinetics (PK) of mycophenolic acid (MPA) and its glucuronide metabolites in stable adult liver transplant recipients with moderately impaired renal function converted from a standard to a low-dose CNI regimen in combination with a fixed dose of MMF. Full 12-hour PK profiles of MPA, free MPA, the aryl glucuronide (MPAG), and the acyl glucuronide (AcMPAG) were obtained from 30 stable liver transplant patients on low-dose CNI (CSA, n = 12; TAC, n = 18) therapy at least 3 months after initiation of low-dose therapy. Predose CSA and TAC concentrations (quantified by liquid chromatography-tandem mass spectrometry) ranged from 17 to 35 and 1.1 to 3.7 microg/L, respectively. The PK variables for MPA, MPAG, AcMPAG, and free MPA displayed wide interindividual variability. Of note was the observation that there were no significant differences in the exposure to MPA, MPAG, and free MPA between the CSA and TAC groups. MPA area under the concentration-time curves (AUCs) ranged from 31.8 to 102.1 (median: 52.9) mg.h(-1).L(-1) in the CSA group and from 22.9 to 144.8 (median: 55.9) mg.h(-1).L(-1) in the TAC group. The AcMPAG AUC on patients under low-dose CSA therapy was higher than that observed under patients on low-dose TAC therapy, although this did not quite reach statistical significance (P = 0.057). Patients receiving CSA had a significantly higher AcMPAG Cmax but not AcMPAG AUC, suggesting that only peak CSA concentrations on a low-dose CSA regimen are sufficient to impair the biliary excretion of AcMPAG. In summary, the influence of CSA on the exposure to MPA was attenuated in stable adult liver transplant recipients on a low-dose CNI therapy in combination with a fixed dose of MMF as compared with patients on a standard CNI therapy. Dose adjustment according to drug concentration measurements is recommended to optimize dosing of MMF and to maintain adequate immunosuppression in patients converted to low-dose CNI therapy.

Models for the prediction of mycophenolic acid area under the curve using a limited-sampling strategy and an enzyme multiplied immunoassay technique in Chinese patients undergoing liver transplantation

BACKGROUND

An enzyme multiplied immunoassay technique (EMIT) provides convenient and accurate measurements of mycophenolic acid (MPA) concentrations for determination of immunosuppression during treatment with mycophenolate mofetil (MMF). No abbreviated model for estimating the full 12-hour MPA AUC using an EMIT assay in liver transplant recipients has been described previously.

OBJECTIVE

This study was conducted to determine the best model for predicting the MPA AUC using the EMIT method and a limited-sampling strategy in Chinese patients undergoing liver transplantation.

METHODS

The study enrolled consecutive liver transplant patients who were receiving MMF 1 g BID along with tacrolimus. A complete MPA pharmacokinetic profile was obtained for each patient on a single day, 7 to 14 days after transplantation. The EMIT method was used to determine MPA concentrations before dosing and at 0.5, 1, 1.5, 2, 4, 6, 8, 10, and 12 hours after dosing on the sampling day. Multiple linear regression analysis was used to evaluate potential models for estimating the full 12-hour MPA AUC. The accuracy and robustness of the models were evaluated using bootstrap analysis. Prediction error and prediction bias were calculated. Agreement between the estimated MPA AUC(0-12) and the full 12-hour MPA AUC was investigated using Bland-Altman analysis.

RESULTS

The study enrolled 48 Chinese liver transplant recipients (45 male, 3 female) with a mean (SD) age of 50 (12) years, mean weight of 64 (12) kg, and mean height of 169 (6) cm. Twenty-four models that included blood sampling at 1 through 4 time points were developed (r(2) = 0.015-0.950). Four models with the highest r(2) values were selected; the lack of significant differences from the original dataset on bootstrap analysis indicated acceptable accuracy and robustness. The best model for predicting the MPA AUC(0-12) employed concentrations at 1, 2, 4, and 8 hours; 40 of 48 (83.3%) MPA AUC(0-12) values estimated using this model were within 15% of the full 12-hour MPA AUC. This model had a minimal mean prediction error (mean [SD], 0.27% [1.79%]) and mean absolute prediction error (8.83% [1.24%]). On Bland-Altman analysis, this model also had the best agreement between the estimated MAP AUC(0-12) and the full 12-hour MPA AUC, with a mean error of 9.02 mg . h/L.

CONCLUSIONS

In this small group of Chinese liver transplant patients receiving MMF and concomitant tacrolimus, models for estimating the MPA AUC(0-12) were developed using the EMIT method and a limited-sampling strategy. The best model for prediction of the full 12-hour MPA AUC was 4.46 + 0.81 . C1 + 1.78 . C(2)+2.51.C(4)+4.94.C8.

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.

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.

Liver transplantation: an update 2007

PURPOSE OF REVIEW

Recent attention in liver transplantation has focused on equity in organ allocation and management of posttransplant complications.

RECENT FINDINGS

Adoption of the model for end-stage liver disease for liver allocation has been successful in implementing a system based on medical urgency rather than waiting time. Refinements are being studied in improving the prediction of mortality and improving transplant benefit by balancing pretransplant mortality and posttransplant survival. Emerging literature is examining expansion of the current criteria for transplantation of hepatocellular carcinoma and the role of neoadjuvant therapy. Chronic renal dysfunction after liver transplantation is a source of considerable morbidity. Nephron-sparing immunosuppression regimens are emerging with encouraging results. Hepatitis C virus infection is difficult to differentiate histologically from rejection, although newer markers are being developed. Antiviral and immunosuppressive strategies for reducing the severity of hepatitis C virus recurrence are discussed. Alcohol relapse is common after liver transplant in alcoholic liver disease patients and can lead to worse outcomes.

SUMMARY

Organ allocation tends to evolve under the model for end-stage liver disease with a focus on maximizing transplant benefit. Hepatitis C virus, hepatocellular carcinoma, chronic renal dysfunction and alcohol relapse are major challenges, and continued research in these areas will undoubtedly lead to better outcomes for transplant recipients.

Pharmacokinetics of mycophenolic acid and determination of area under the curve by abbreviated sampling strategy in Chinese liver transplant recipients

OBJECTIVES

This study aimed to: (i) define the clinical pharmacokinetics of mycophenolic acid (MPA) in Chinese liver transplant recipients; and (ii) develop a regression model best fitted for the prediction of MPA area under the plasma concentration-time curve from 0 to 12 hours (AUC(12)) by abbreviated sampling strategy.

METHODS

Forty liver transplant patients received mycophenolate mofetil 1g as a single dose twice daily in combination with tacrolimus. MPA concentrations were determined by high-performance liquid chromatography before dose (C(0)) and at 0.5 (C(0.5)), 1 (C(1)), 1.5 (C(1.5)), 2 (C(2)), 4 (C(4)), 6 (C(6)), 8 (C(8)), 10 (C(10)) and 12 (C(12)) hours after administration on days 7 and 14. A total of 72 pharmacokinetic profiles were obtained. MPA AUC(12) was calculated with 3P97 software. The trough concentrations (C(0)) of tacrolimus and hepatic function were also measured simultaneously. Multiple linear regression analysis was used to establish the models for estimated MPA AUC(12). The agreement between predicted MPA AUC(12) and observed MPA AUC(12) was investigated by Bland-Altman analysis.

RESULTS

The pattern of MPA concentrations during the 12-hour interval on day 7 was very similar to that on day 14. In the total of 72 profiles, the mean maximum plasma concentration (C(max)) and time to reach C(max) (t(max)) were 9.79 +/- 5.26 mg/L and 1.43 +/- 0.78 hours, respectively. The mean MPA AUC(12) was 46.50 +/- 17.42 mg . h/L (range 17.99-98.73 mg . h/L). Correlation between MPA C(0) and MPA AUC(12) was poor (r(2) = 0.300, p = 0.0001). The best model for prediction of MPA AUC(12) was by using 1, 2, 6 and 8 hour timepoint MPA concentrations (r(2) = 0.921, p = 0.0001). The regression equation for estimated MPA AUC(12) was 5.503 + 0.919 . C(1) + 1.871 . C(2) + 3.176 . C(6) + 3.664 . C(8). This model had minimal mean prediction error (1.24 +/- 11.19%) and minimal mean absolute prediction error (8.24 +/- 7.61%). Sixty-three of 72 (88%) estimated MPA AUC(12) were within 15% of MPA AUC(12). Bland-Altman analysis also revealed the best agreement of this model compared with the others and a mean error of +/-9.89 mg . h/mL.

CONCLUSION

This study showed the wide variability in MPA AUC(12) in Chinese liver transplant recipients. Single timepoint MPA concentration during the 12-hour dosing interval cannot reflect MPA AUC(12). MPA AUC(12) could be predicted accurately using 1, 2, 6 and 8 hour timepoint MPA concentrations by abbreviated sampling strategy.

Pharmacokinetic evaluation of mycophenolic acid profiles during the period immediately following an orthotopic liver transplant

BACKGROUND

Area under the curve (AUC) limited sampling strategies have been proposed to improve the efficiency of mycophenolic acid (MPA), treatment of the transplanted patient. Our objective was to develop a model in the initial phase of the transplantation that explains the variability in the pharmacokinetic behavior of MPA in the immediate posttransplant period, following treatment with mycophenolate mofetil (MMF) in adult liver transplantation.

METHODS

One hundred ten pharmacokinetic simplified sampling profiles were collected, including four samples over a 6-hour postdose interval, in over 60 patients treated with cyclosporine or tacrolimus, MMF, and steroids, combining Daclizumab in more than a third of the patients. For an enzyme-multiplied immunoassay technique method was established for MPA estimates. The correlation between the AUC and the plasma concentration points was established using a multiple linear regression with various equations for three different pharmacokinetic groups.

RESULTS

The maximum mean values of MPA AUC and predose concentration (C0h) (20.8 +/- 11.8 and 2.3 +/- 1.8, respectively) were reached on the third day. The single sample showing the greatest correlation with the MPA AUC was the one collected after 3 hours (r(2) = 0.575); 59.1% of profiles displayed a single peak with more than half showing a tmax >/= 3 hours.

CONCLUSIONS

This profile analysis during the first few weeks highlighted the problems in determining therapeutic targets. Profiles showing a double peak revealed the marked influence of the enterohepatic cycle on MPA concentrations during the initial phase.

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.

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.

Efficacy of mycofenolate mofetil for steroid-resistant acute rejection after living donor liver transplantation

AIM: To discuss the use of mycophenolate mofetil (MMF) as an immunosuppressant in steroid resistant rejection after liver transplantation.

METHODS: The clinical records of 260 adult patients who underwent living donor liver transplantation (LDLT) were reviewed. Tacrolimus and methylprednisolone were used for primary immunosuppression. Acute rejection was first treated with steroids. When steroid resistance occurred, the patient was treated with a combination of steroids and MMF. Anti-T-cell monoclonal antibody was administered to patients who were not responsive to steroids in combination with MMF.

RESULTS: A total of 90 (35%) patients developed acute rejection. The median interval time from transplantation to the first episode was 15 d. Fifty-four patients were steroid resistant. Forty-four patients were treated with MMF and the remaining 10 required anti-T-cell monoclonal antibody treatment. Progression to chronic rejection was observed in one patient. Bone marrow suppression and gastrointestinal symptoms were the most common side effects associated with MMF use. There was no significant increase in opportunistic infections.

CONCLUSION: Our results demonstrate that MMF is a potent and safe immunosuppressive agent for rescue therapy in patients with acute rejection after LDLT.

Liver transplantation: an update

PURPOSE OF REVIEW

Recent attention in liver transplantation has focused on equity in organ allocation and management of post-transplant complications.

RECENT FINDINGS

Adoption of the model for end-stage liver disease (MELD) for liver allocation has been successful in implementing a system based on medical urgency rather than waiting time. Refinements are being studied in reducing geographic disparities and improving transplant benefit by balancing pre-transplant mortality and post-transplant survival. With hepatocellular carcinoma becoming a bigger proportion of liver transplants since MELD, emerging literature is examining expansion of the current criteria for transplantation of hepatocellular carcinoma. Hepatitis C virus infection is associated with worse patient and graft survival post-transplantation than other liver diseases. The optimal timing and delivery of current antiviral therapy and immunosuppressive strategies in reducing the severity of hepatitis C virus recurrence post-transplantation are discussed. Chronic renal dysfunction after liver transplantation is a source of considerable morbidity. Nephron-sparing immunosuppression regimens are emerging with encouraging results.

SUMMARY

Organ allocation tends to evolve under MELD with a focus on reducing geographic disparities and maximizing transplant benefit. Hepatitis C virus, hepatocellular carcinoma and chronic renal dysfunction are a major challenge and continued research in these areas will undoubtedly lead to better outcomes for transplant recipients.

Long-term results of mycophenolate mofetil as part of immunosuppressive induction therapy after liver transplantation

BACKGROUND

The addition of mycophenolate mofetil (MMF) to the induction protocol resulted in a lower incidence of rejection episodes. However, the question whether MMF should be administered in combination with tacrolimus or cyclosporine has not been answered yet. In our study, we report on the long-term results of triple induction therapy after orthotopic liver transplantation (OLT), consisting of MMF and low-dose corticosteroids, in combination with either tacrolimus or cyclosporine.

METHODS

Between March 1996 and April 1997, 120 consecutive patients, who underwent OLT at our institution, were enrolled in this study. Of these patients, 80 received triple induction therapy consisting of cyclosporine and MMF (40) or tacrolimus and MMF (40), in combination with low-dose corticosteroids, whereas the remaining 40 patients served as 'MMF-free' control group receiving dual induction therapy with tacrolimus and corticosteroids. Besides the eight-yr follow-up of patient and graft survival, clinical data were also reviewed for episodes of rejection and infection. Additionally, the early post-operative pharmacokinetics of mycophenolic acid (MPA, immunological active metabolite of MMF) were evaluated.

RESULTS

Long-term results provided higher patient and graft survival after tacrolimus/MMF-based induction therapy than after cyclosporine/MMF-based induction therapy. However, the tacrolimus-based control protocol yielded similar results and, therefore, no significantly superior effect was observed when MMF was added. The same observation was made for incidence of rejection and infection episodes. AUC and C(max) of MPA increased in combination with tacrolimus compared with cyclosporine.

CONCLUSIONS

Although pharmacological synergy between tacrolimus and MMF was observed, MMF showed no significant beneficial effects in the immunosuppressive induction protocol, neither in combination with tacrolimus nor with cyclosporine.

Posttransplantation chronic renal damage in nonrenal transplant recipients

BACKGROUND

The growing problem of relentless deterioration of renal function in patients who undergo transplantation of nonrenal solid organs is bound to have an increasingly important impact as it may not only worsen patient morbidity and mortality but also increase transplantation costs.

METHODS

We reviewed the literature in order to provide a sum of the most important data on the incidence, clinical picture, renal pathology pattern, damage mechanisms, and risk factors, along with strategies for prevention and treatment of chronic renal damage following nonrenal solid organ transplantation.

RESULTS

Literature data report that 10% to 80% of transplanted patients have some degree of renal dysfunction and that they share a common clinical picture characterized by relentless asymptomatic progression, frequent hypertension, mild urinary abnormalities, and pathology features of vascular, glomerular, tubular, and interstitial involvement. These changes are very similar to those reported for chronic nephrotoxicity from calcineurin inhibitors. The occurrence of end-stage renal disease (ESRD) requiring chronic dialysis has been reported in up to 20% of nonrenal transplant recipients. Although there are some organ-specific differences, a group of common risk factors has been recognized, including the use of calcineurin inhibitors as immunosuppressive agents, age, pretransplantation renal function, intraoperative/perioperative factors, concomitant use of other nephrotoxic drugs, infections, and posttransplantation acute renal failure.

CONCLUSION

Calcineurin inhibitor-induced nephrotoxicity is a growing problem and, as the age of recipients of nonrenal organs is increasing, this problem is destined to increase. It would therefore be advisable for nephrologists to share their experiences in immunomodulation with other specialties, so as to favor the cautious extension of calcineurin inhibitor-sparing protocols to the area of life-saving transplants.

Kidney dysfunction in the recipients of liver transplants

1. Pretransplant kidney function is an important predictor of posttransplant kidney function. 2. Chronic kidney disease is present in 20% of liver transplant recipients by 5 years. 3. Kidney function is impacted by pretransplant management of the consequences of the hepatorenal syndrome. 4. The use of calcineurin inhibitor (CNI)-based immunosuppression is an important factor in the development of chronic kidney disease, and the use of mycophenolic acid- or sirolimus-based immunosuppression with reduced-dose CNI may be of benefit.