Management of renal dysfunction in the liver transplant recipient. Curr Opin Organ Transplant. 2009;14:231-239. [PMID: 19395967 DOI: 10.1097/mot.0b013e32832b34a4]

Effect of dexmedetomidine on the incidence of postoperative acute kidney injury in living donor liver transplantation recipients: a randomized controlled trial

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications after living-donor liver transplantation (LDLT) that has great impact on recipient and graft outcomes. Dexmedetomidine is reported to decrease the incidence of AKI. In the current study, the authors investigated whether intraoperative dexmedetomidine infusion would reduce the AKI following LDLT.

MATERIAL AND METHODS

In total, 205 adult patients undergoing elective LDLT were randomly assigned to the dexmedetomidine group ( n =103) or the control group ( n =102). Dexmedetomidine group received continuous dexmedetomidine infusion at a rate of 0.4 mcg/kg/h after the anesthesia induction until 2 h after graft reperfusion. The primary outcome was to compare the incidence of AKI. Secondary outcomes included serial lactate levels during surgery, chronic kidney disease, major adverse cardiovascular events, early allograft dysfunction, graft failure, overall mortality, duration of mechanical ventilation, intensive care unit, and hospital length of stay. Intraoperative hemodynamic parameters were also collected.

RESULTS

Of 205 recipients, 42.4% ( n =87) developed AKI. The incidence of AKI was lower in the dexmedetomidine group (35.0%, n =36/103) compared with the control (50.0%, n =51/102) ( P =0.042). There were significantly lower lactate levels in the dexmedetomidine group after reperfusion [4.39 (3.99-4.8) vs 5.02 (4.62-5.42), P =0.031] until the end of surgery [4.23 (3.73-4.74) vs 5.35 (4.84-5.85), P =0.002]. There were no significant differences in the other secondary outcomes besides lactate. Also, intraoperative mean blood pressure, cardiac output, and systemic vascular resistance did not show any difference.

CONCLUSION

Our study suggests that intraoperative dexmedetomidine administration was associated with significantly decreased AKI incidence and lower intraoperative serum lactate levels in LDLT recipients, without untoward hemodynamic effects.

Experience with the mTOR Inhibitor Everolimus in Pediatric Liver Graft Recipients

INTRODUCTION

Immunosuppression after pediatric liver transplantation remains a major challenge. MTOR inhibitors provide a promising therapeutic approach in combination with reduced CNI after transplantation. However, there are still few data regarding their use in children.

PATIENTS

We analyzed 37 patients with a median age of 10 years, who received Everolimus for one or more of the following indications: I = chronic graft dysfunction (n = 22); II = progressive renal impairment (n = 5); III = non-tolerable side effects with previous immunosuppressive medication (n = 6); and IV = malignancies (n = 10). The median follow-up time was 36 months.

RESULTS

Patient survival was 97%, and graft survival 84%, respectively. Stabilization of graft function was observed in 59% in subgroup 1, with 18.2% ultimately requiring retransplantation. No patient in subgroup IV developed recurrence of his primary tumor or PTLD by the endpoint of the study. Side effects were observed in 67.5% of the study patients, with infections being the most frequent (n = 20; 54.1%). There were no relevant effects on growth and development.

CONCLUSION

Everolimus seems to be a treatment option in selected pediatric liver graft recipients for whom other regimens are not suitable. Overall, the efficacy was good and the side effect profile appeared to be acceptable.

Continuous Renal Replacement Therapy after Liver Transplantation: Peri-Operative Associated Factors and Impact on Survival

Continuous renal replacement therapy (CRRT) following orthotopic liver transplantation (OLT) is usually started for multifactorial reasons, with variable incidence among series. This paper presents a single-center retrospective observational study on the early use (within one week) of CRRT after consecutive cadaveric OLT from January 2008 to December 2016. Preoperative patient characteristics and intraoperative data were collected, and patients were divided into two groups (CRRT and no CRRT) to explore the factors associated with the use of CRRT. Repeated measurements of postoperative creatinine were analyzed with generalized estimating equation (GEE) models. Among 528 OLT patients, 75 (14.2%) were treated with CRRT at least once in the first week. Patients treated with CRRT showed lower survival in a Kaplan−Meier curve (log-rank p value < 0.01). Patients treated with CRRT had a more severe preoperative profile, with a significantly higher age, MELD, BUN, creatinine, and total bilirubin, as well as a longer surgery time and a higher number of transfusions of red blood cells, plasma, and platelets (all p values < 0.05). In a stepwise multiple analysis, the following characteristics remained independently associated with the use of CRRT: the MELD score OR 1.12 (95% CL: 1.07−1.16), p value < 0.001, and the preoperative value for blood urea nitrogen OR 1.016 (95% CL: 1.010−1.023), p value < 0.001. The early use of CRRT after OLT occurred at a low rate in this large cohort; however, it was associated with worse outcomes. Apart from the preoperative severity, repeated intraoperative hypotension episodes, which were likely modifiable or preventable, were associated with the increased use of CRRT and higher postoperative creatinine.

Optimal timing of initiating CRRT in patients with acute kidney injury after liver transplantation

BACKGROUND

Acute kidney injury (AKI) is a frequent complication after liver transplantation (LT), and is associated with high mortality. Continuous renal replacement therapy (CRRT) is an important treatment for AKI, but the optimal time for initiation is still controversial. The purpose of this study was to investigate the prognostic effect of initial CRRT treatment time.

METHODS

We retrospectively reviewed the clinical data of 173 recipients undergoing LT from January 2018 to March 2019. AKI was defined according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. All patients receiving CRRT were divided into early and late group according to urine output. Prognosis was compared between the two groups.

RESULTS

A total of 48 (27.8%) patients were identified with AKI, 23 (13.3%) of whom received CRRT. According to urine output, 13 (56.5%) patients were in early group and 10 (43.5%) patients in late group. AKI was associated with longer intensive care unit (ICU) and hospital stay, increased post-operative 90-day mortality and the incidence of early allograft dysfunction (EAD). Patients in late CRRT group had a longer ICU stay {median, IQR, 183.5 [92.25-336.75] vs. 139 [94-240] hours, P=0.043} and hospital stay {median, IQR, 38.5 [17.5-62.75] vs. 35 [17-38] days, P=0.019} than patients in early CRRT group, respectively. The rate of severe infection was significantly higher in the late CRRT group than in the early CRRT group (80.0% vs. 30.8%, P=0.026).

CONCLUSIONS

AKI was associated with longer length of ICU and hospital stay, poor short-term mortality and functional recovery of transplanted organ. Early initiation of CRRT could reduce the severe infection and length of ICU and hospital stay.

Immunosuppressive regimens for adult liver transplant recipients in real-life practice: consensus recommendations from an Italian Working Group

It is a well-recognized fact that implementing new guidelines in clinical practice may be difficult; therefore the Italian Society for Organ and Tissue Transplantation (SITO) set out to define practical immunosuppression tools for the management of liver transplantation patients. In 2017, an Italian Working Group of liver transplant experts and hepatologists issued a set of consensus statements along with evidence-based recommendations on the use of everolimus after liver transplantation. This article presents the evidence- and consensus-based algorithms developed within the Italian Working Group, which are aimed towards guiding clinicians in the selection of immunosuppressive regimens for the management of adult liver transplant recipients in real-life practice. The liver transplant recipient population, typically managed in clinical practice, was divided into the following categories: (1) standard patients; (2) critically ill patients; (3) patients with a specific etiology; (4) patients with hepatocellular carcinoma; (5) and patients with de novo malignancies. The algorithms are divided into two parts, according to the time from transplantation (0-3 months and > 3 months) and are discussed here along with relevant supporting literature, when available. Ultimately, it is hoped that the evidence- and consensus-based algorithms developed within the Italian Working Group, and presented here, contribute to simplify, personalize, and optimize immunosuppression of liver transplantation recipients in clinical practice.

SNPs Within the MTOR Gene Are Associated With an Increased Risk of Developing De Novo Diabetes Mellitus Following the Administration of Everolimus in Liver Transplant Recipients

BACKGROUND

The impact of immunosuppressive drugs in patients following liver transplantation (LT) is very individual. Despite the multiple beneficial effects of the mammalian target of rapamycin (mTOR) inhibitor everolimus (EVR) in LT recipients, some patients do not benefit from EVR administration. We investigated whether the presence of common single-nucleotide polymorphisms (SNPs) in the mTOR gene are predictive for adverse events following the introduction of EVR after LT.

MATERIALS AND METHODS

The feasibility and efficacy of EVR in 127 liver transplant recipients who were converted to EVR-based immunosuppression was documented retrospectively. Blood samples of these patients were analyzed for the occurrence of 4 SNPs in the mTOR promoter region (mTOR3099/rs2295079 C>G, mTOR3162/rs2295080 A>C) and the mTOR 3' untranslated regio (mTOR8167/rs12139042 C>T, mTOR8600/rs2536 A>G); the specific allele variants were also associated with the incidence of adverse events (AEs).

RESULTS

Of all patients, 21 (16.5%) did not tolerate the medication and had to discontinue. Of those patients who continued, 37% developed signs of reduced tolerance within the first 6 months, resolving after 12 months. When the cohort was divided according to genotype and allele frequency, patients with the mTOR3162/rs2295080 CC variant had a significantly higher risk (odds ratio = 5.89; 95% confidence interval = 1.48-23.40; P = .012) of developing new-onset diabetes mellitus following EVR treatment than AA or AC genotype carriers.

CONCLUSION

Our results suggest that the SNP mTOR3162/rs2295080 CC genotype is associated with the development of new-onset diabetes mellitus following EVR treatment.

Renal Dysfunction after Living-Donor Liver Transplantation: Experience with 500 Cases

Introduction. The possible risk factors for chronic kidney disease in transplant recipients have not been thoroughly investigated after living-donor liver transplantation. Material and Methods. A retrospective cohort study of consecutive adults who underwent living-donor liver transplantation between May 2004 and October 2016, in a single center, was conducted. Kidney function was investigated successively for all the patients throughout the study period, with 12 months being the shortest follow-up. Postoperative renal dysfunction was defined in accordance with the Chronic Kidney Disease Epidemiology Collaboration criteria. The patients' demographic data, preoperative and intraoperative parameters, and outcomes were recorded. A calcineurin inhibitor-based immunosuppressive regimen, either tacrolimus or cyclosporine, was used in all the patients. Results. Of the 413 patients included in the study, 33 (8%) who survived for ≥1 year experienced chronic kidney disease 1 year after living-donor liver transplantation. Twenty-seven variables were studied to compare between the patients with normal kidney functions and those who developed chronic kidney disease 1 year after living-donor liver transplantation. Univariate regression analysis for predicting the likelihood of chronic kidney disease at 1 year revealed that the following 4 variables were significant: operative time, P < 0.0005; intraoperative blood loss, P < 0.0005; preoperative renal impairment, P = 0.001; and graft-to-recipient weight ratio (as a negative predictor), P < 0.0005. In the multivariate regression analysis, only 2 variables remained as independent predictors of chronic kidney disease at 1 year, namely, operative time with a cutoff value of ≥714 minutes and graft-to-recipient weight ratio as a negative predictor with a cutoff value of <0.91. Conclusion. In this study, prolonged operative time and small graft-to-recipient weight ratio were independent predictors of chronic kidney disease at 1 year after living-donor liver transplantation.

Chronic Kidney Disease after Liver Transplantation: Recent Evidence

Chronic kidney disease is a common complication after liver transplantation with an incidence ranging between 20% and 80%. Studies of renal function after liver transplantation have yielded conflicting results: the wide range in incidence rates of chronic kidney disease (CKD) following liver transplantation is related to the methods for measuring kidney function, and various criteria for defining renal dysfunction, among others. An important cause of CKD among liver transplant recipients is calcineurin inhibitor-based immunosuppression. Additional predictors of CKD post-liver transplantation include pre-transplant kidney function, peri-operative acute kidney failure, age, and hepatitis C. A recent meta-analysis of observational studies revealed that, in the subgroup of studies provided with glomerular filtration rate at baseline, the summary estimate of relative risk and 95% confidence intervals (CI) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01–4.46, p=0.047). Acute renal insufficiency is common immediately after liver transplantation, whereas the course of CKD after liver transplantation appears progressive over time. Only preliminary information exists on kidney pathological findings in recipients of liver transplants with CKD. Introduction of the Model for End-stage Liver Disease for the allocation of liver grafts has not increased the occurrence of renal dysfunction following liver transplantation. Chronic kidney disease following liver transplantation increases cardiovascular burden dramatically. The use of mycophenolic acid- or sirolimus-based immunosuppression in calcineurin-inhibitors sparing protocols is an area of intense research.

PREOPERATIVE RISK FACTORS FOR ACUTE KIDNEY INJURY AFTER LIVER TRANSPLANTATION: RESULTS FROM A CROSS-SECTIONAL STUDY IN NORTHEAST OF BRAZIL

BACKGROUND

Acute kidney injury (AKI) is a common complication in the immediate postoperative period of patients undergoing liver transplantation.

OBJECTIVE

The aim of this study was to evaluate preoperative risk factors for AKI after liver transplantation.

METHODS

A cross-sectional study was conducted with adults submitted to orthotopic liver transplantation at a reference hospital in Fortaleza, Northeast of Brazil, from January to December 2016. Preoperative risk factors were evaluated for AKI development in the immediate postoperative period. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

RESULTS

A total of 40 patients were included in the study. AKI was found in 85% of patients in the first 24 hours after transplantation, most of them (40%) classified in KDIGO stage 1. Preoperative data indicate that serum albumin levels were lower in the KDIGO stage 3 group compared to the non-AKI group, as well as the hematocrit levels. Direct bilirubin (DB) was higher in the KDIGO stage 3 group compared to the group without AKI, as well as alkaline phosphatase (AP) and gamma-glutamiltransferase (GGT). In a logistic regression analysis independent risk factors for AKI were increase levels of AP, GGT and DB and decrease level of serum albumin.

CONCLUSION

Low levels of serum albumin, and elevated levels of DB, AP and GGT in the preoperative period are risk factors for AKI development after liver transplantation.

Postoperative acute kidney injury in living donor liver transplantation recipients

PURPOSE

There are many risk factors for postoperative acute kidney injury in liver transplantation. The aim of this study is to investigate the risk factors for postoperative acute kidney injury in living donor liver transplantation recipients.

METHODS

220 living donor liver transplantation recipients were retrospectively evaluated in the study. According to the Kidney Disease Improving Global Outcomes Guidelines, acute kidney injury in postoperative day 7 was investigated for all patients. The patient's demographic data, preoperative and intraoperative parameters, and outcomes were recorded.

RESULTS

Acute kidney injury was found in 27 (12.3%) recipients. In recipients with acute kidney injury, female population, model for end-stage liver disease score, norepinephrine requirement, duration of mean arterial pressure less than 60 mmHg, the usage of gelatin and erythrocyte suspension and blood loss were significantly higher than recipients with nonacute kidney injury (for all p<0.05). In multivariate analyses, the likelihood of acute kidney injury on postoperative day 7 were increased 2.8-fold (1.1-7.0), 2.7-fold (1.02-7.3), 3.4-fold (1.2-9.9) and 5.1-fold (1.7-15.0) by postoperative day 7, serum tacrolimus level ≥10.2 ng dL-1, intraoperative blood loss ≥14.5 mL kg-1, the usage of gelatin >5 mL kg-1 and duration of MAP less than 60 mmHg ≥5.5 minutes respectively (for all p<0.05).

CONCLUSIONS

In living donor liver transplantation recipients, serum tacrolimus levels, intraoperative blood loss, hypotension period and the usage of gelatin may be risk factors for acute kidney injury in the early postoperative period.

Use of Everolimus in Liver Transplantation: Recommendations From a Working Group

Immunosuppression after liver transplantation (LT) is presently based on use of calcineurin inhibitors (CNI), although they are associated with an increased incidence of renal dysfunction, cardiovascular complications, and de novo and recurrent malignancies. Over the past decade, mammalian target of rapamycin inhibitors have received considerable attention as immunosuppressants because they are associated with a more favorable renal profile versus CNI, as well as antiproliferative activity in clinical studies. Comprehensive guidelines on use of everolimus (EVR) in LT are still lacking. In Italy, a project, named Everolimus: the road to long-term functioning, was initiated to collect the experience on EVR after LT with the aim of providing guidance for transplant clinicians. Herein, recommendations by this national consensus group, based on Delphi methodology, are presented. Consensus was reached on 20 of the 23 statements proposed, and their level of evidence, grade of recommendation, and percent of agreement are reported. Statements are grouped into 4 areas: (A) renal function; (B) time of EVR introduction, CNI reduction and elimination, and risk for graft rejection; (C) antiproliferative effects of EVR; and (D) management of EVR-related adverse events. The high level of consensus shows that there is good agreement on the routine use of EVR in predefined clinical scenarios, especially in light of posttransplant nephrotoxicity and other adverse events associated with long-term administration of CNIs.

The authors summarize the recommendations reached by an Italian National Consensus group using the Delphi methodology on the use of everolimus in liver transplantation, particularly its role in renal function, antiproliferative effects, adverse events, timing of introduction, and rejection risk.

Impact of preoperative chronic renal failure on liver transplantation: a population-based cohort study

Purpose

The purpose of this study was to assess whether preoperative chronic renal failure (CRF) affects the rates of postoperative complications and survival after liver transplantation.

Methods

This population-based retrospective cohort study included 2,931 recipients of liver transplantation performed between 1998 and 2012, enrolled from the Taiwan National Health Insurance Research Database. Patients were divided into two groups, based on the presence or absence of preoperative CRF.

Results

The overall estimated survival rate of liver transplantation recipients (LTRs) with preoperative CRF was significantly lower than that of patients without preoperative CRF (P=0.0085). There was no significant difference between the groups in terms of duration of intensive care unit stay, total hospital stay, bacteremia, postoperative bleeding, and pneumonia during hospitalization. Long-term adverse effects, including cerebrovascular disease and coronary heart disease, were not different between patients with versus without CRF.

Conclusion

These findings suggest that LTRs with preoperative CRF have a higher rate of mortality.

Cost-effectiveness of everolimus plus reduced tacrolimus in de novo liver-recipients in the Italian setting

INTRODUCTION

Long-term exposure to calcineurin inhibitor-based immunosuppressant (IS) therapy in liver transplant (LT) recipients is associated with renal complications. In the randomized trial H2304, everolimus + reduced-dose tacrolimus (EVR + rTAC) demonstrated equivalent efficacy and superior renal function compared to standard-dose tacrolimus.

METHODS

To evaluate the cost-effectiveness of EVR + rTAC vs TAC, in de novo LT patients, a Markov model simulating both liver and kidney function was developed and estimated the long-term outcomes of IS following LT. The analysis used the Italian healthcare payer perspective.

RESULTS

Patients treated with EVR + rTAC gained on average 1.92 years and 1.62 quality-adjusted life years (QALYs). The incremental cost-effectiveness ratios (ICER) were €35,851 and €42,567 for LY gained and QALY gained, respectively. For the hepatitis-c sub-population, the ICERs decreased to €22,519 and €30,658, respectively.

CONCLUSION

EVR + rTAC improves survival and quality-of-life and is a cost-effective alternative to calcineurin-inhibitor monotherapy for patients requiring LT.

Hypoalbuminemia Within Two Postoperative Days Is an Independent Risk Factor for Acute Kidney Injury Following Living Donor Liver Transplantation: A Propensity Score Analysis of 998 Consecutive Patients

OBJECTIVE

Acute kidney injury is a known major complication of liver transplantation. Previous reports have shown that hypoalbuminemia is associated with an increased risk of acute kidney injury. However, little is known about the relationship between the early postoperative albumin level and acute kidney injury after living donor liver transplantation. The aim of this study was to identify the influence of the postoperative albumin level on acute kidney injury prevalence after living donor liver transplantation.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PATIENTS

Nine hundred and ninety-eighty patients underwent living donor liver transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We divided the enrolled patients into two groups: group 1 included patients whose postoperative albumin level was less than 3.0 g/dL (n = 522), and group 2 included patients with an albumin level greater than or equal to 3.0 g/dL (n = 476). The prevalence of acute kidney injury, major adverse cardiac events, hospital stay, ICU stay, 30-day mortality, and overall mortality was analyzed using inverse probability of treatment weighting and propensity-score matching (n = 249 pairs) analysis. The prevalence of acute kidney injury was higher in group 1 defined by both Acute Kidney Injury Network (after adjusting for inverse probability of treatment weighting [n = 364; 69.7%] and propensity-score matching [n = 152; 61.0%]) and Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (after adjusting for inverse probability of treatment weighting [n = 419; 80.3%] and propensity-score matching [n = 190; 76.3%]). The overall mortality was higher in group 1 after adjusting for inverse probability of treatment weighting (n = 61; 11.7%) and propensity-score matching (n = 23; 9.2%). The hospital (p < 0.001) and ICU (p = 0.006) stays were significantly prolonged in group 1. Acute kidney injury was associated with ICU stay by the Acute Kidney Injury Network criteria (p = 0.034), and overall mortality was correlated with acute kidney injury by the Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (p = 0.014).

CONCLUSIONS

Early postoperative hypoalbuminemia is an independent risk factor for acute kidney injury, and postoperative acute kidney injury is related to postoperative ICU stay and overall mortality after living donor liver transplantation.

Dexmedetomidine Pretreatment Attenuates Kidney Injury and Oxidative Stress during Orthotopic Autologous Liver Transplantation in Rats

This paper aims to explore whether pretreatment with dexmedetomidine (Dex) has antioxidative and renal protective effects during orthotopic autologous liver transplantation (OALT) and its impact on nuclear factor erythroid 2-related factor 2 (Nrf2) activation. Sprague-Dawley rats were randomized into groups that include sham-operated (group S), model (group M), low dose Dex (group D1), high dose Dex (group D2), atipamezole (a nonspecific α₂ receptor blocker) + high dose Dex (group B1), ARC239 (a specific α_2B/c receptor blocker) + high dose Dex (group B2), and BRL-44408 (a specific α_2A receptor blocker) + high dose Dex (group B3). Then histopathologic examination of the kidneys and measurement of renal function, the renal Nrf2 protein expression, and oxidants and antioxidants were performed 8 hours after OALT. We found that pretreatment with Dex activated Nrf2 in glomerular cells and upregulated antioxidants but reduced oxidants (all P < 0.01, group D2 versus group M). Atipamezole and BRL-44408, but not ARC239, reversed these protective effects. In conclusion, pretreatment with Dex activates Nrf2 through α_2A receptor, increases the antioxidant levels, and attenuates renal injury during OALT.

Underestimation of chronic renal dysfunction after liver transplantation: ICEBERG study

AIM: To compare prevalence of chronic renal dysfunction (CRD) according to serum creatinine (sCr) vs estimated glomerular filtration rate (eGFR) among maintenance liver transplant patients.

METHODS: The ICEBERG study was an observational, retrospective, cross-sectional, and multicenter study. Consecutive adult patients (aged 18 years or older) with liver transplantation (LT) performed at least two years previously were recruited. Multi-organ transplant recipients were excluded. Chronic renal dysfunction was defined according to sCr based criteria in routine clinical practice (≥ 2 mg/dL) and eGFR using MDRD-4 equation (< 60 mL/min per 1.73 m²). Agreement between sCr definition and eGFR assessment was evaluated using the Kappa index. Cox regression analysis was applied to identify predictive factors for developing CRD after LT.

RESULTS: A total of 402 patients were analyzed (71.6% males). Mean ± SD age at transplant was 52.4 ± 9.8 years. Alcoholic cirrhosis without hepatocellular carcinoma was the most common reason for LT (32.8%). Mean time since LT was 6.9 ± 3.9 years. Based on sCr assessment, 35.3% of patients (95%CI: 30.6-40.0) had CRD; 50.2% (95%CI: 45.3-55.1) according to eGFR. In 32.2% of cases, sCr assessment had underestimated CRD. Multivariate analysis showed the following factors associated with developing CRD: eGFR < 60 mL/min per 1.73 m² at three months post-transplant [hazard ratio (HR) = 4.76; 95%CI: 2.78-8.33; P < 0.0001]; calcineurin inhibitor use (HR = 2.31; 95%CI: 1.05-5.07; P = 0.0371); male gender (HR = 1.98; 95%CI: 1.09-3.60; P = 0.0260); and ≥ 10 years post-transplantation (HR = 1.95; 95%CI: 1.08-3.54; P = 0.0279).

CONCLUSION: Seven years after LT, CRD affected half our patients, which was underestimated by sCr. An eGFR < 60 mL/min per 1.73 m² three months post-LT was predictive of subsequent CRD.

Intravenous fenoldopam for early acute kidney injury after liver transplantation

PURPOSE

Acute kidney injury remains a serious complication after orthotopic liver transplantation. To date, several 'renal-protective' agents have been explored in this setting but with conflicting and disappointing results. Therefore, our aim is to evaluate the effects of fenoldopam in liver transplant patients with an established renal injury.

METHODS

In this prospective study, intravenous fenoldopam 0.1 µg/kg/min was administered to consecutive liver transplant patients with postoperative (within 7 days from surgery) stage 2 acute kidney injury (AKI) according to the Acute Kidney Injury Network classification. Actual glomerular filtration rate (GFR; calculated by the iohexol plasma clearance), serum creatinine (SCr) and cystatin C (SCyC) were used to assess the effect of the medication on the patients.

RESULTS

During the study, 295 patients underwent liver transplant. Fifty-one patients (17.6%) met the inclusion criteria and the data from 48 patients were analysed. SCr and SCyC levels decreased (p < 0.001 after 48 h; p < 0.0001 after 72 h) and GFR increased (p < 0.001 after 24 h; p < 0.0001 after 72 h). When compared to a cohort of comparable patients with AKI from our historical series, the patients in the present study showed better SCr and SCyC levels. It was not necessary to discontinue the infusion of fenoldopam in any patient because of the occurrence of adverse events potentially attributable to it.

CONCLUSION

We showed that fenoldopam was capable of improving some renal function parameters in postoperative liver transplantation patients with on-going AKI. This preliminary study now sets the stage for a multicenter, randomized, placebo-controlled trial in order to provide definite evidence.

The role of everolimus in liver transplantation

During the last 5 decades, liver transplantation has witnessed rapid development in terms of both technical and pharmacologic advances. Since their discovery, calcineurin inhibitors (CNIs) have remained the standard of care for immunosuppression therapy in liver transplantation, improving both patient and graft survival. However, adverse events, particularly posttransplant nephrotoxicity, associated with long-term CNI use have necessitated the development of alternate treatment approaches. These include combination therapy with a CNI and the inosine monophosphate dehydrogenase inhibitor mycophenolic acid and use of mammalian target of rapamycin (mTOR) inhibitors. Everolimus, a 40-O-(2-hydroxyethyl) derivative of mTOR inhibitor sirolimus, has a distinct pharmacokinetic profile. Several studies have assessed the role of everolimus in liver transplant recipients in combination with CNI reduction or as a CNI withdrawal strategy. The efficacy of everolimus-based immunosuppressive therapy has been demonstrated in both de novo and maintenance liver transplant recipients. A pivotal study in 719 de novo liver transplant recipients formed the basis of the recent approval of everolimus in combination with steroids and reduced-dose tacrolimus in liver transplantation. In this study, everolimus introduced at 30 days posttransplantation in combination with reduced-dose tacrolimus (exposure reduced by 39%) showed comparable efficacy (composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, or death) and achieved superior renal function as early as month 1 and maintained it over 2 years versus standard exposure tacrolimus. This review provides an overview of the efficacy and safety of everolimus-based regimens in liver transplantation in the de novo and maintenance settings, as well as in special populations such as patients with hepatocellular carcinoma recurrence, hepatitis C virus-positive patients, and pediatric transplant recipients. We also provide an overview of ongoing studies and discuss potential expansion of the role for everolimus in these settings.

Belatacept-based immunosuppression in de novo liver transplant recipients: 1-year experience from a phase II randomized study

This exploratory phase II study evaluated the safety and efficacy of belatacept in de novo adult liver transplant recipients. Patients were randomized (N = 260) to one of the following immunosuppressive regimens: (i) basiliximab + belatacept high dose [HD] + mycophenolate mofetil (MMF), (ii) belatacept HD + MMF, (iii) belatacept low dose [LD] + MMF, (iv) tacrolimus + MMF, or (v) tacrolimus alone. All received corticosteroids. Demographic characteristics were similar among groups. The proportion of patients who met the primary end point (composite of acute rejection, graft loss, death by month 6) was higher in the belatacept groups (42–48%) versus tacrolimus groups (15–38%), with the highest number of deaths and grafts losses in the belatacept LD group. By month 12, the proportion surviving with a functioning graft was higher with tacrolimus + MMF (93%) and lower with belatacept LD (67%) versus other groups (90%: basiliximab + belatacept HD; 83%: belatacept HD; 88%: tacrolimus). Mean calculated GFR was 15–34 mL/min higher in belatacept-treated patients at 1 year. Two cases of posttransplant lymphoproliferative disease and one case of progressive multifocal leukoencephalopathy occurred in belatacept-treated patients. Follow-up beyond month 12 revealed an increase in death and graft loss in another belatacept group (belatacept HD), after which the study was terminated.

Neutrophil gelatinase-associated lipocalin associated with irreversibility of pre-liver transplant kidney dysfunction

Kidney outcomes in early post-liver transplantation (LT) are crucial for long-term prognosis, but difficult to predict. Among 203 adult LT patients, we studied the value of plasma neutrophil gelatinase-associated lipocalin (NGAL) measured pre-LT for predicting acute kidney injury (AKI), kidney-replacement therapy within three months, and kidney dysfunction at three months post-LT. Glomerular filtration rate (GFR) was estimated by creatinine-based and cystatin C-based equations. Highest NGAL levels were among patients on pre-LT kidney-replacement therapy, whereas NGAL exceeded 200 μg/L in only three (2%) patients with pre-LT GFR >60 mL/min. Pre-LT NGAL >260 μg/L predicted GFR <60 mL/min at three months post-LT (OR 17.8, 95% CI 2.1-153) independently of 19 other variables reflecting recipient characteristics, liver and kidney function, perioperative hemodynamic stress, and immunosuppression. Of 81 patients with pre-LT GFR <60 mL/min, 48% had GFR <60 mL/min at three months, and an NGAL level >260 μg/L predicted this outcome with 90% specificity and 46% sensitivity. NGAL failed to predict post-LT AKI or need for temporary kidney-replacement therapy. In conclusion, NGAL independently predicted irreversibility of pre-LT kidney dysfunction and could thus help in optimizing patient care and in the decision to perform combined liver-kidney transplantation. Pre-LT NGAL was not useful in patients with preserved pre-LT kidney function or in predicting post-LT AKI.

Negative prognostic impact of renal replacement therapy in adult living-donor liver transplant recipients: preoperative recipient condition and donor factors

BACKGROUND

In deceased-donor liver transplantation settings, post-transplantation acute renal failure with the induction of renal replacement therapy (RRT) is known to have negative effects on graft and patient survivals. However, the impact of RRT in living-donor liver transplantation (LDLT) has not been well investigated. The aim of this study was to elucidate risk factors requiring RRT and prognostic factors after its induction.

METHODS

Clinical data on the consecutive 113 adult patients who underwent LDLT from March 2002 to May 2013 were retrospectively reviewed. They were divided into 2 groups: RRT (n = 33) and Non-RRT (n = 80). The primary reasons for receiving RRT were hepatorenal syndrome (n = 17), sepsis (n = 12), and renal hypoperfusion (n = 4).

RESULTS

Although there were no significant differences in age or sex, the Model for End-Stage Liver Disease (MELD) score was significantly higher in the RRT group than in the Non-RRT group (23 ± 13 vs 16 ± 7; P = .002). The graft-recipient weight ratio (GRWR) was significantly lower in the RRT group (0.86 ± 0.3 vs 0.99 ± 0.2; P = .025). The 1- and 5-year patient survival rates were significantly higher in the Non-RRT group than in the RRT group (respectively, 91.3% and 84.3% vs 42.9% and 25.5%; P < .001). In multivariate analysis, independent risk factors for receiving RRT were MELD score >20 (P = .044) and GRWR <0.7 (P = .039). In the RRT group, donor age >50 years (P = .042) and preoperative serum creatinine level >1.5 mg/dL (P = .049) were significant prognostic risk factors.

CONCLUSIONS

In adult LDLT patients, the induction of RRT after LDLT was a negative predictor of survival. In addition to the preoperative recipient's condition, donor factors including graft size and donor age influenced prognosis after the induction of RRT.

Prediction of newly developed acute renal failure using serum phosphorus concentrations after living-donor liver transplantation

OBJECTIVE

This retrospective study investigated the predictive role of serum phosphorus concentration for acute renal failure (ARF), defined by the Risk Injury Failure Loss End-stage kidney disease (RIFLE) criteria, after living-donor liver transplantation (LDLT).

METHODS

Perioperative factors, including serum phosphorus concentrations, in LDLT recipients without pre-existing renal dysfunction were retrospectively analysed and compared between patients with or without post-LDLT ARF.

RESULTS

A total of 45 patients out of 350 (12.9%) met the RIFLE ARF criteria and experienced significantly higher postoperative mortality, longer intensive care unit stay and more frequent graft dysfunction than those patients without post-LDLT ARF. Multivariate logistic regression analyses showed that a serum phosphorus concentration ≥ 4.5 mg/dl on postoperative day 1 (relative risk [RR] 5.31; 95% confidence interval [CI] 2.56, 11.03), a preoperative model for end-stage liver disease score 20 points (RR 4.17, 95% CI 2.04, 8.52), and packed red blood cell transfusion 10 units (RR 2.55, 95% CI 1.13, 5.88) were independent risk factors for post-LDLT ARF.

CONCLUSIONS

Hyperphosphataemia on postoperative day 1 could be an early and simple indicator of ARF occurrence after LDLT.

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.

Cardiovascular and renal complications in patients receiving a solid-organ transplant

PURPOSE OF REVIEW

Cardiovascular and renal complications among solid-organ transplant recipients are a frequent source of morbidity. Appropriate management of these complications throughout the perioperative period significantly affects long-term recipient survival. This review details the identification, management, and potential preventive strategies for perioperative cardiovascular and renal complications among solid-organ transplant recipients.

RECENT FINDINGS

Abdominal transplant candidates have a significantly higher prevalence of risk factors for obstructive coronary artery disease than the general population. There is no consensus on pretransplant screening for coronary artery disease or determination of perioperative risk in candidates awaiting transplantation. Limitations of noninvasive cardiac screening tests such as dobutamine stress echocardiography and myocardial perfusion scintigraphy complicate preoperative evaluation and cardiac risk stratification. Coronary angiography remains the definitive mechanism for determining the presence and severity of coronary artery disease prior to transplantation; however, the relationship between angiographically documented coronary artery disease and cardiovascular morbidity after transplantation is inconsistent. This has raised speculation that perioperative adverse cardiac events are not principally caused by obstructive coronary artery disease but other acute events related to surgical intervention and allograft function. Current data indicate coronary angiography is safe even with patients demonstrating renal insufficiency. A cardiac screening program should reflect the patient population, dynamics of the transplant program, and institutional expertise. The development of classification schemes for defining and categorizing acute kidney injury reflects the importance of preserved renal function in long-term recipient survival. The potential of serum markers as indicators of acute kidney injury has provided a foundation for understanding the global influence of surgical intervention and allograft function upon recipient survival.

SUMMARY

Meticulous attention to all aspects of the transplant process, including operative events and early allograft function, is necessary to minimize morbidity. Further research is necessary to identify mechanisms that support and improve early allograft function to optimize recipient long-term survival.

Post liver transplantation acute kidney injury in a rat model of syngeneic orthotopic liver transplantation

Acute kidney injury (AKI) is a frequent complication after liver transplantation (LT). The mechanism of post-LT AKI remains unclear. We used the rat model of syngeneic orthotopic LT (SOLT) to investigate the mechanism of post-LT AKI. We hypothesized that the condition of the graft, rather than intraoperative hemodynamic instability, has an important role in post-LT AKI in the SOLT model. Rats were randomly assigned into four groups: sham-operated group; vessel-clamped group; full-size LT group; and reduced-size LT group. We identified AKI in both full-size and reduced-size LT groups. In addition to renal tubular necrosis and apoptosis, renal peritubular capillary injury was also present. Pathological changes were more severe in the reduced-size than in the full-size LT group. We found that the systemic inflammatory response induced by LT was the initiating factor in post-LT AKI. This is the first study to investigate the pathological mechanism of AKI in an animal model of SOLT. Our results demonstrate that protection of the liver graft and inhibition of the systemic inflammatory response are vital in reducing the risk of post-LT AKI.

One thousand consecutive primary liver transplants under tacrolimus immunosuppression: a 17- to 20-year longitudinal follow-up

BACKGROUND

Tacrolimus has proven to be a potent immunosuppressive agent in orthotopic liver transplantation (OLT). The aim of this study is to examine its long-term efficacy and safety.

METHODS AND RESULTS

One thousand consecutive primary OLTs performed between August 1989 and December 1992 and maintained under tacrolimus-based immunosuppression were followed up until January 2009. Patient and graft survivals with corresponding causes of death and retransplantation, maintenance immunosuppression, and adverse effects were examined. The study population includes 600 males and 400 females comprising 166 children, 630 adults, and 204 seniors. The mean follow-up was 17.83 (range, 16.1-19.50) years. The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively. At the last follow-up, 442 patients were alive; 133 (77.1%) children, 265 (34.5%) adults, and 44 (16.1%) seniors (P=0.0001). After the first post-OLT year, cardiopulmonary events, recurrence of primary disease, and malignancy were the main causes of death. Overall, 183 recipients underwent retransplants; mainly for primary nonfunction, hepatic artery thrombosis, and recurrent primary disease, 180 required dialysis, and 45 underwent kidney transplant. A total of 97.7% of the survivors were on tacrolimus and 26.2% were also receiving adjunctive immunosuppressants at the last follow-up.

CONCLUSIONS

The overall 20-year actuarial patient and graft survivals were 35.8% and 32.6%, respectively, with significantly better survival among children. Age-related complications, recurrence of primary disease, and malignancy were the major causes of late graft loss. Graft loss related to immunologic reasons was rare. The prevention of recurrent disease and newer immunosuppressive regimen will further improve these results.

Long-term results of liver transplantation

Liver transplantation (LT) is an established therapy associated with a dramatic improvement in patients life expectancy. With improved early-term management, current 10-year patient survival rates in many indications exceed 70%. Life-long immunosuppressive therapy may, however, be accompanied by considerable longterm toxicity: most importantly, renal dysfunction, cardiovascular disease, and cancer, which, in addition to recurrence of the primary liver disease, emerge as key contributors to late mortality. Chronic kidney disease cumulatively affects up to 28% of patients by ten years after LT. Various factors can contribute to renal impairment, but perioperative acute kidney injury, calcineurin inhibitor toxicity, hypertension, and diabetes are considered most important. LT patients demonstrate 3-fold risk for cardiovascular events, which seems to result mostly from an excess of traditional risk factors, mainly hypertension and diabetes. The cumulative cancer incidence reaches 16-42% by 20 years after LT, and cancer rates are 2- to 4-fold higher among LT patients than among matched controls. Highest rates are for nonmelanoma skin cancer (3- to 70-fold) and lymphoma (8- to 29-fold). The liver graft usually displays uncomplicated function in the long term. Most common causes for chronic graft dysfunction include disease recurrence and biliary problems. LT generally restores patients quality of life to a level comparable with that of the general population, with only minor deficits in some areas. Thus, long-term survival after LT is impressive, and despite these long-term complications, patients quality of life remains comparable with that of the general population.

Pre-transplant kidney function predicts chronic kidney disease after liver transplant: meta-analysis of observational studies

BACKGROUND

Chronic kidney disease is a common problem in long-term survivors after liver transplantation. Several studies to clarify the risk factors for incidence of chronic kidney disease among liver transplant recipients, including preoperative kidney function, have yielded conflicting results.

AIM

The aim of this study was to conduct a systematic review of the published medical literature on the impact of pre-transplant kidney function on the occurrence of chronic kidney disease after liver transplantation.

METHODS

Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates for incidence of chronic kidney disease across the published studies. The relative risk of chronic kidney disease after liver transplantation according to pre-transplant glomerular filtration rate was regarded as the most reliable outcome end-point.

RESULTS

We identified seven studies (38,036 unique liver transplant recipients). A stratified analysis including only studies provided with glomerular filtration rate at transplant reported that the summary estimate of relative risk and 95% confidence intervals (CIs) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01; 4.46) (random-effects model). The p value for study heterogeneity was significant (p = 0.0001). Post-transplant chronic kidney disease shows impact on survival; the summary estimate for the adjusted relative risk of all-cause mortality with chronic kidney disease after liver transplant was 4.35 (95% confidence Intervals, 3.34; 5.66), p = 0.0001 (random-effects model).

CONCLUSIONS

An increased risk of chronic kidney disease frequently exists among liver transplant recipients with reduced renal function at transplant. The occurrence of chronic kidney disease after liver transplantation has a major impact on mortality. Additional studies are needed to understand better the natural history of chronic kidney disease among liver transplant recipients.

Critical care issues in patients after liver transplantation

The majority of patients who undergo liver transplantation (LT) spend some time in the intensive care unit during the postoperative period. For some, this is an expected part of the immediate posttransplant recovery period, whereas for others, the stay is more prolonged because of preexisting conditions, intraoperative events, or postoperative complications. In this review, 4 topics that are particularly relevant to the postoperative intensive care of LT recipients are discussed, with an emphasis on current knowledge specific to this patient group. Infectious complications are the most common causes of early posttransplant morbidity and mortality. The common patterns of infection seen in patients after LT and their management are discussed. Acute kidney injury and renal failure are common in post-LT patients. Kidney injury identification, etiologies, and risk factors and approaches to management are reviewed. The majority of patients will require weaning from mechanical ventilation in the immediate postoperative period; the approach to this is discussed along with the approach for those patients who require a prolonged period of mechanical ventilation. A poorly functioning graft requires prompt identification and appropriate management if the outcomes are to be optimized. The causes of poor graft function are systematically reviewed, and the management of these grafts is discussed.

Acute kidney injury after liver, heart, and lung transplants: dialysis modality, predictors of renal function recovery, and impact on survival

Recipients of nonrenal organ transplants including the liver, heart, and lung are at risk for developing acute kidney injury (AKI) and chronic kidney disease (CKD). Underlying hepatic or cardiopulmonary failure, prolonged intraoperative hemodynamic instability, and the use of calcineurin inhibitors and nephrotoxic medications have all been suggested to be contributory. The incidence of perioperative AKI has been reported to occur in 17% to 95% in liver transplant recipients, 5% to 30% in heart transplant recipients, and 5% to 60% in recipients of lung transplants. Among those who develop AKI, renal replacement therapy is required in 5% to 35%, 5% to 15%, and 8% to 10% in liver, heart, and lung transplant recipients, respectively. The current article presents an overview of the literature on the choice of dialysis modality and its associated advantages and disadvantages in the management of AKI after liver, heart, and lung transplants. Predictive factors for renal function recovery and the impact of AKI and CKD on survival will also be discussed.