Experience Since MELD Implementation: How Does the New System Deliver?

Lesson learnt from 60 years of liver transplantation: Advancements, challenges, and future directions

Over the past six decades, liver transplantation (LT) has evolved from an experimental procedure into a standardized and life-saving intervention, reshaping the landscape of organ transplantation. Driven by pioneering breakthroughs, technological advancements, and a deepened understanding of immunology, LT has seen remarkable progress. Some of the most notable breakthroughs in the field include advances in immunosuppression, a revised model for end-stage liver disease, and artificial intelligence (AI)-integrated imaging modalities serving diagnostic and therapeutic roles in LT, paired with ever-evolving technological advances. Additionally, the refinement of transplantation procedures, resulting in the introduction of alternative transplantation methods, such as living donor LT, split LT, and the use of marginal grafts, has addressed the challenge of organ shortage. Moreover, precision medicine, guiding personalized immunosuppressive strategies, has significantly improved patient and graft survival rates while addressing emergent issues, such as short-term complications and early allograft dysfunction, leading to a more refined strategy and enhanced post-operative recovery. Looking ahead, ongoing research explores regenerative medicine, diagnostic tools, and AI to optimize organ allocation and post-transplantation car. In summary, the past six decades have marked a transformative journey in LT with a commitment to advancing science, medicine, and patient-centered care, offering hope and extending life to individuals worldwide.

The Development and Appraisal of MELD 3.0 in Liver Diseases: Good Things Never Come Easy

Since its proposal, the Model for End-Stage Liver Disease (MELD) score has been employed to predict short-term mortality among patients with chronic liver disease and those awaiting liver transplantation, serving as the primary criterion for organ allocation. However, as the demographic and epidemiological characteristics of chronic liver disease and liver transplantation have evolved, a range of MELD-related scores has emerged, including MELD-Na, iMELD, delta MELD, MELD XI, MELD-LA, and pediatric end-stage liver disease, culminating in the recently proposed MELD 3.0, which builds upon MELD-Na. This study aimed to comprehensively review and summarize relevant studies on MELD 3.0 in various scenarios, assessing its effectiveness in organ allocation, post-transplantation outcomes, and mortality prediction for patients with end-stage liver disease. Our preliminary findings indicate superior predictive performance of MELD 3.0, warranting further in-depth investigations to broaden its clinical implications.

"Beyond MELD" - Emerging strategies and technologies for improving mortality prediction, organ allocation and outcomes in liver transplantation

In this review article, we discuss the model for end-stage liver disease (MELD) score and its dual purpose in general and transplant hepatology. As the landscape of liver disease and transplantation has evolved considerably since the advent of the MELD score, we summarise emerging concepts, methodologies, and technologies that may improve mortality prognostication in the future. Finally, we explore how these novel concepts and technologies may be incorporated into clinical practice.

Disadvantage of Small (<60 kg) Adult Candidates on the Liver Transplantation Waitlist

BACKGROUND

Small adult patients with lower bodyweight wait-listed for liver transplantation may face a shortage of size-matched whole-liver grafts. The objective of this study is to compare time to transplantation in adult patients with a bodyweight of <60 kg to patients with bodyweight ≥60 kg.

METHODS

A matched case-control study was conducted. Patients aged 18 years and older listed for liver transplantation at our transplant center, from 2007 to 2016 with a bodyweight <60 kg were manually matched 1:2 to control patients ≥ 60 kg. Matching was performed based on ABO blood type, model for end-stage liver disease score, (non)-standard exception status, and eligibility for donation after cardiac death. Time to transplantation was assessed with univariable Cox-regression.

RESULTS

In total, 23 cases with a bodyweight < 60 kg were matched to 46 average-sized control patients. Small adults were significantly disadvantaged for receiving a liver transplantation as compared to their average-sized counterpart (hazard ratio 0.47; 95% confidence interval 0.29-0.75, P = .002). At the end of follow-up, 14/23 (60.9%) of cases versus 35/46 of controls (76.1%) had received a liver transplantation.

CONCLUSION

Small adults with a bodyweight below 60 kg are disadvantaged on the waitlist for a size-matched whole liver graft.

The trials and tribulations of liver allocation

Allocation policies are necessary to ensure a fair distribution of a scarce resource. The goal of any liver transplant allocation policy is to achieve the best possible outcomes for the waiting list population, irrespective of the indication for transplant, whilst maximizing organ utilization. Organ allocation for liver transplantation has evolved from simple centre-based approaches driven by local issues, to complex, evidence-based algorithm prioritizing according to need. Despite the rapid evolution of allocation policies, there remain a number of challenges and new approaches are required to ensure transparency and equity on the decision-making process and the best possible outcomes for patients on the waiting list. New ways of modelling, together with novel outcome criteria, will be required to enable a dynamic adaptability of the allocation policies to the ever changing demographics of the donor population and the changing landscape of indications for transplantation.

Secondary sclerosing cholangitis in critically ill patients has a poor outcome but lower tumour incidence than primary sclerosing cholangitis

BACKGROUND

Secondary sclerosing cholangitis in critically ill patients (SSC-CIP) is an emerging disease with grim prognosis.

OBJECTIVE

Our aim was the analysis of prognostic factors, long-term outcome and risk of tumour development in SSC-CIP compared with primary sclerosing cholangitis (PSC) patients.

METHODS

Retrospective analysis between 2008 and 2018.

RESULTS

One hundred and eleven patients with SSC-CIP and 408 PSC patients were identified. Median orthotopic liver transplantation (OLT)-free survival was 16 months for SSC-CIP and 147 months for PSC (p < 0.001). OLT was performed in 18/111 SSC-CIP compared with 166/408 PSC patients (p < 0.001). Malignant tumours were detected in 17.9% of PSC patients (73/408) compared with 2.7% (3/111) in SSC-CIP (p < 0.001). In multivariate Cox regression analysis low levels of C-reactive protein (hazard ratio 4.687 (95% confidence interval (CI) 1.144-19.199, p = 0.032) were significantly associated with a prolonged survival whereas higher age (hazard ratio 0.488 (95% CI 0.23-1.038), p = 0.062) showed a trend for shorter survival in SSC-CIP. For PSC malignancies (hazard ratio 0.42 (95% CI 0.313-0.575), p < 0.001) and higher age (hazard ratio 0.709 (95% CI 0.544-0.922), p = 0.01) were associated with a shorter OLT-free survival.

CONCLUSION

SSC-CIP is characterized by acute onset of liver disease and poor prognosis but with lower tumour incidence compared with PSC.

Impact of Italian Score for Organ Allocation System on Deceased Donor Liver Transplantation: A Monocentric Competing Risk Time-to-Event Analysis

BACKGROUND

Liver transplantation (LT) is the only definitive and curative treatment for patients with end-stage liver disease and hepatocellular carcinoma. We aimed to evaluate the impact of the Italian score for organ allocation (ISO) in terms of the waiting-list mortality, probability of LT, and patient survival after LT.

PATIENT AND METHODS

All of the adult patients on the waiting list for LT at our institute from January 2014 to December 2017 were included in the study. The probabilities of death while on the waiting list, dropout from the list, and LT were compared by means of cumulative incidence functions, in a competing risk time-to-event analysis setting. Uni- and multivariable logistic regression models were used to estimate and compare the probability of death and to find potential risk factors for waiting-list death.

RESULTS

There were 286 patients on the waiting list for LT during the study period, 122 of whom entered the waiting list prior to the implementation of ISO (Group A) and 164 afterward (Group B). Group A had 62 transplants, and Group B had 116 transplants. Group B showed a lesser probability of death (P = .005) and a greater probability of transplant (P < .001) compared to Group A. In the 2 groups, post-transplant survival was similar.

CONCLUSION

Based on preliminary clinical experience from a single transplant center, the ISO allocation system demonstrated an overall reduced probability of patient death while on the waiting list without impairing post-LT survival, suggesting that the ISO system might represent an improved method of organ allocation, with a more beneficial distribution of livers.

Potential value and limitations of different clinical scoring systems in the assessment of short- and long-term outcome following orthotopic liver transplantation

BACKGROUND

In an attempt to further improve liver allograft utilization and outcome in orthotopic liver transplantation (OLT), a variety of clinical scoring systems have been developed. Here we aimed to comparatively investigate the association of the Balance-of-Risk (BAR), Survival-Outcomes-Following-Liver-Transplant (SOFT), Preallocation-Survival-Outcomes-Following-Liver-Transplant (pSOFT), Donor-Risk-Index (DRI), and the Eurotransplant-Donor-Risk-Index (ET-DRI) scores with short- and long-term outcome following OLT.

METHODS

We included 338 consecutive patients, who underwent OLT in our institution between May 2010 and November 2017. For each prognostic model, the optimal cutoff values were determined with the help of the Youden-index and their diagnostic accuracy for 90-day post OLT-mortality and major postoperative complications was measured by the area under the receiver operating characteristic curve (AUROC). Patient- and graft survival were analyzed using the Kaplan-Meier method and the log-rank test. Morbidity was assessed using the Clavien-Dindo classification and the Comprehensive-Complication-Index.

RESULTS

BAR, SOFT, and pSOFT performed well above the conventional AUROC-threshold of 0.70 with good prediction of early mortality. Only BAR showed AUC>0.70 for both mortality and major morbidity. With the cutoffs of 14, 31, and 22 respectively for BAR, SOFT, and pSOFT, subgroup analysis showed significant differences (p<0.001) in morbidity and mortality, length of intensive care- and hospital-stay and early allograft dysfunction rates. Five-years patient survival was inferior in the high BAR, pSOFT, and SOFT groups.

CONCLUSIONS

Out of all scores tested, the BAR-score had the best value in predicting both 90-day morbidity and mortality after OLT showing the highest AUCs. The pSOFT and SOFT scores demonstrated an acceptable accuracy in predicting 90-day morbidity and mortality. The used BAR, SOFT, and pSOFT cutoffs allowed the identification of patients at risk in terms of five-year patient survival. The DRI and ET-DRI scores have failed to predict recipient outcomes in the present setting.

Is Muscle MELD a More Promising Predictor for Mortality After Living Donor Liver Transplantation?

BACKGROUND

To improve the outcome of living donor liver transplantation (LDLT), a scoring system that could predict accurately the patient and graft survival posttransplant is necessary. The aim of this study is to evaluate our previously proposed Muscle-model for end-stage liver disease (M-MELD) score and to compare it with the other available scores to find the best system that correlates with postoperative outcome after liver transplant.

METHODS

We retrospectively reviewed the data of 199 patients who underwent LDLT from January 2010 to July 2016 and calculated the preoperative MELD, MELD Na, the product of donor age and MELD (D-MELD), M-MELD, integrated MELD, and the balance of risk (BAR) score in all patients. The area under the receiver operating characteristics curves (AUCs) of each score was computed and compared at 3-, 6-months, and 1-year after LDLT.

RESULTS

The M-MELD, D-MELD, and integrated MELD had a good discriminative performance in predicting 3-month mortality after LDLT with AUCs > 0.7, while the M-MELD was the only score that showed a good discriminative performance in predicting 6-month and 1-year mortality after LDLT with AUCs > 0.7.

CONCLUSION

Muscle-MELD score is a simple and useful predictor of patient survival after LDLT which showed a better predictive performance than other available scores.

Wait-list mortality of young patients with Biliary atresia: Competing risk analysis of a eurotransplant registry-based cohort

Liver transplantation (LT) is the standard treatment for biliary atresia (BA) patients with end-stage liver disease. The prognosis after LT has steadily improved, but overall prognosis of BA patients is also determined by mortality before LT. We aimed to quantify mortality in young BA patients on the Eurotransplant waiting list and to determine the effect of disease severity and age at time of listing on pretransplant mortality. We used a cohort study design, which incorporated data from the Eurotransplant registry. Participants were 711 BA patients who were below 5 years of age from 5 countries and listed for LT between 2001 and 2014. We applied a competing risk analysis to evaluate simultaneously the outcomes death, LT, and still waiting for a suitable organ. We used Cox proportional hazards regression to assess 2-year mortality. In a subcohort of 416 children, we performed multivariate analyses between 2-year mortality and disease severity or age, each at listing. Disease severity at listing was quantified by the Model for End-Stage Liver Disease (MELD) score, which assesses bilirubin, creatinine, albumin, and international normalized ratio as continuous variables. Two-year wait-list mortality was 7.9%. Age below 6 months and MELD score above 20 points, each at listing, were strongly and independently associated with 2-year mortality (each P < 0.001). A total of 21% of infants who fulfilled both criteria did not survive the first 6 months on the waiting list. In conclusion, our findings quantify mortality among young BA patients on the waiting list and the relative importance of risk factors (age and severity of disease at listing). Our results provide both an evidence base to rationally address high mortality in subgroups and a methodology to assess effects of implemented changes, for example, in allocation rules. Liver Transplantation 24 810-819 2018 AASLD.

Adult Liver Allocation in Eurotransplant

Liver allocation in Eurotransplant is complex because allocation rules need to follow not only the guidelines of the European Commission but also the specific regulations of each of the 7 Eurotransplant countries with active liver transplant programs. Thirty-eight liver transplant centers served a population of about 135 million in 2015. Around 1600 deceased donor livers are transplanted annually. The number of deceased organ donors remains stable but donor age is increasing. Nevertheless, liver utilization rates are unchanged at around 80%. Donation after circulatory determination of death (DCD) increased fourfold in the past decade. In Belgium and the Netherlands, DCDs were responsible for 30% of deceased donor liver transplant activity in 2015; Austria only occasionally transplants a DCD liver; other Eurotransplant countries do not have active DCD programs. The most frequent indications for liver transplantation are alcoholic liver disease, hepatocellular carcinoma, and viral hepatitis. Livers are allocated first internationally to high urgency status patients or those with an approved combined organ status (for a liver in combination with heart, lung, intestine, or pancreas) and then on a national basis where allocation is recipient-driven or center-driven, depending on country-specific rules. Median waiting time for an elective liver transplant was 4,4 months in 2015; high urgency status patients waited a median of 2 days for a suitable liver. Mortality on the waiting list was 18% in 2015, 4% of patients were delisted because they became unfit for transplantation. One-year and 5-year risk unadjusted adult patient survival after transplantation is 80% and 65%, respectively.

Impact of preoperative infection on outcome after liver transplantation

BACKGROUND

Bacterial infection in patients with liver failure can lead to a dramatic clinical deterioration. The indications for liver transplantation and outcome in these patients is still controversial.

METHODS

All adult patients who underwent liver transplantation between 1 January 2010 and 31 December 2015 were selected from an institutional database. Characteristics of the donors and recipients, and clinical, biochemical and surgical parameters were retrieved from the database. Post-transplant survival rates and complications, including grade III-IV complications according to the Dindo-Clavien classification, were compared between patients with an infection 1 month before transplantation and patients without an infection.

RESULTS

Eighty-four patients with an infection had statistically significant higher Model for End-stage Liver Disease (MELD), D-MELD and Balance of Risk (BAR) scores and a higher rate of acute-on-chronic liver failure compared with findings in 343 patients with no infection. The rate of infection after liver transplantation was higher in patients who had an infection before the operation: 48 per cent versus 30·6 per cent in those with no infection before transplantation (P = 0·003). The percentage of patients with a postoperative complication (42 versus 40·5 per cent respectively; P = 0·849) and the 90-day mortality rate (8 versus 6·4 per cent; P = 0·531) was no different between the groups. Multivariable analysis showed that a BAR score greater than 18 and acute-on-chronic liver failure were independent predictors of 90-day mortality.

CONCLUSION

Bacterial infection 1 month before liver transplantation is related to a higher rate of infection after transplantation, but does not lead to a worse outcome.

Risk Assessment in High- and Low-MELD Liver Transplantation

Allocation of liver grafts triggers emotional debates, as those patients, not receiving an organ, are prone to death. We analyzed a high-Model of End-stage Liver Disease (MELD) cohort (laboratory MELD score ≥30, n = 100, median laboratory MELD score of 35; interquartile range 31-37) of liver transplant recipients at our center during the past 10 years and compared results with a low-MELD group, matched by propensity scoring for donor age, recipient age, and cold ischemia time. End points of our study were cumulative posttransplantation morbidity, cost, and survival. Six different prediction models, including donor age x recipient MELD (D-MELD), Difference between listing MELD and MELD at transplant (Delta MELD), donor-risk index (DRI), Survival Outcomes Following Liver Transplant (SOFT), balance-of-risk (BAR), and University of California Los Angeles-Futility Risk Score (UCLA-FRS), were applied in both cohorts to identify risk for poor outcome and high cost. All score models were compared with a clinical-oriented decision, based on the combination of hemofiltration plus ventilation. Median intensive care unit and hospital stays were 8 and 26 days, respectively, after liver transplantation of high-MELD patients, with a significantly increased morbidity compared with low-MELD patients (median comprehensive complication index 56 vs. 36 points [maximum points 100] and double cost [median US$179 631 vs. US$80 229]). Five-year survival, however, was only 8% less than that of low-MELD patients (70% vs. 78%). Most prediction scores showed disappointing low positive predictive values for posttransplantation mortality, such as mortality above thresholds, despite good specificity. The clinical observation of hemofiltration plus ventilation in high-MELD patients was even superior in this respect compared with D-MELD, DRI, Delta MELD, and UCLA-FRS but inferior to SOFT and BAR models. Of all models tested, only the BAR score was linearly associated with complications. In conclusion, the BAR score was most useful for risk classification in liver transplantation, based on expected posttransplantation mortality and morbidity. Difficult decisions to accept liver grafts in high-risk recipients may thus be guided by additional BAR score calculation, to increase the safe use of scarce organs.

Impact of MELD Allocation System on Waiting List and Early Post-Liver Transplant Mortality

BACKGROUND AND AIMS

MELD allocation system has changed the clinical consequences on waiting list (WL) for LT, but its impact on mortality has been seldom studied. We aimed to assess the ability of MELD and other prognostic scores to predict mortality after LT.

METHODS

301 consecutive patients enlisted for LT were included, and prioritized within WL by using the MELD-score according to: hepatic insufficiency (HI), refractory ascites (RA) and hepatocellular carcinoma (HCC). The analysis was performed to predict early mortality after LT (8 weeks).

RESULTS

Patients were enlisted as HI (44.9%), RA (19.3%) and HCC (35.9%). The major aetiologies of liver disease were HCV (45.5%). Ninety-four patients (31.3%) were excluded from WL, with no differences among the three groups (p = 0.23). The remaining 207 patients (68.7%) underwent LT, being HI the most frequent indication (42.5%). HI patients had the shortest length within WL (113.6 days vs 215.8 and 308.9 respectively; p<0.001), but the highest early post-LT mortality rates (18.2% vs 6.8% and 6.7% respectively; p<0.001). The independent predictors of early post-LT mortality in the HI group were higher bilirubin (OR = 1.08; p = 0.038), increased iMELD (OR = 1.06; p = 0.046) and non-alcoholic cirrhosis (OR = 4.13; p = 0.017). Among the prognostic scores the iMELD had the best predictive accuracy (AUC = 0.66), which was strengthened in non-alcoholic cirrhosis (AUC = 0.77).

CONCLUSION

Patients enlisted due to HI had the highest early post-LT mortality rates despite of the shortest length within WL. The iMELD had the best accuracy to predict early post-LT mortality in patients with HI, and thus it may benefit the WL management.

Comparison of five models for end-stage liver disease in predicting the survival rate of patients with advanced hepatocellular carcinoma

Prognosis of patients with advanced hepatocellular carcinoma (HCC) is under expectation. Life expectancy more than 3 months is one inclusion criteria for molecular targeted drugs in clinical trials. The main purpose of this research is to compare Model for End-Stage Liver Disease (MELD) and four MELD-based prognostic models in predicting the survival rate of advanced HCC patients. One hundred eighty-three patients with advanced HCC who were not amendable to standard anti-tumor therapy were retrospectively analyzed. Data were collected to classify patients according to MELD, Model for End-Stage Liver Disease with the incorporation of serum sodium (MELD-NA), Model for End-Stage Liver Disease to ascites and sodium (MELD-AS), integrated Model for End-Stage Liver Disease (iMELD), and Model for End-Stage Liver Disease to sodium (MESO) scores at diagnosis. 1-, 3-, and 6-month survivals were the end points used in the analysis. When predicting 1-month survival, MELD-AS, MELD, and MESO were the top 3 ranking staging systems. When predicting 3-month survival, area under the receiver operating characteristic curve (AUC) of MELD-AS is significantly higher than that of the other models (P < 0.05). When predicting 6-month survival, AUCs of MELD-AS and MELD-NA are significantly higher than those of the other models (P < 0.05). Cutoff point of MELD-AS is 23.11 with 40.5 % sensitivity and 93.8 % specificity at 1 month, 9.5 with 76.9 % sensitivity and 59.5 % specificity at 3 months, and 18.5 with 27.0 % sensitivity and 89.1 % specificity at 6 months. MELD-based scores of death group are significantly higher than those of survivors within 1 and 3 months (P < 0.001). Independent prognostic factors identified by multivariate analysis included persistent ascites, serum sodium, and thrombosis. MELD-AS is the best model in the prediction of short and intermediate survival among the five models for end-stage liver disease analyzed for Chinese advanced HCC patients.

The PER (Preoperative Esophagectomy Risk) Score: A Simple Risk Score to Predict Short-Term and Long-Term Outcome in Patients with Surgically Treated Esophageal Cancer

Esophageal resection in patients with esophageal cancer (EC) is still associated with high mortality and morbidity rates. We aimed to develop a simple preoperative risk score for the prediction of short-term and long-term outcomes for patients with EC treated by esophageal resection. In total, 498 patients suffering from esophageal carcinoma, who underwent esophageal resection, were included in this retrospective cohort study. Three preoperative esophagectomy risk (PER) groups were defined based on preoperative functional evaluation of different organ systems by validated tools (revised cardiac risk index, model for end-stage liver disease score, and pulmonary function test). Clinicopathological parameters, morbidity, and mortality as well as disease-free survival (DFS) and overall survival (OS) were correlated to the PER score. The PER score significantly predicted the short-term outcome of patients with EC who underwent esophageal resection. PER 2 and PER 3 patients had at least double the risk of morbidity and mortality compared to PER 1 patients. Furthermore, a higher PER score was associated with shorter DFS (P < 0.001) and OS (P < 0.001). The PER score was identified as an independent predictor of tumor recurrence (hazard ratio [HR] 2.1; P < 0.001) and OS (HR 2.2; P < 0.001). The PER score allows preoperative objective allocation of patients with EC into different risk categories for morbidity, mortality, and long-term outcomes. Thus, multicenter studies are needed for independent validation of the PER score.

Factors Associated with Mortality and Graft Failure in Liver Transplants: A Hierarchical Approach

BACKGROUND

Liver transplantation has received increased attention in the medical field since the 1980s following the introduction of new immunosuppressants and improved surgical techniques. Currently, transplantation is the treatment of choice for patients with end-stage liver disease, and it has been expanded for other indications. Liver transplantation outcomes depend on donor factors, operating conditions, and the disease stage of the recipient. A retrospective cohort was studied to identify mortality and graft failure rates and their associated factors. All adult liver transplants performed in the state of São Paulo, Brazil, between 2006 and 2012 were studied.

METHODS AND FINDINGS

A hierarchical Poisson multiple regression model was used to analyze factors related to mortality and graft failure in liver transplants. A total of 2,666 patients, 18 years or older, (1,482 males; 1,184 females) were investigated. Outcome variables included mortality and graft failure rates, which were grouped into a single binary variable called negative outcome rate. Additionally, donor clinical, laboratory, intensive care, and organ characteristics and recipient clinical data were analyzed. The mortality rate was 16.2 per 100 person-years (py) (95% CI: 15.1-17.3), and the graft failure rate was 1.8 per 100 py (95% CI: 1.5-2.2). Thus, the negative outcome rate was 18.0 per 100 py (95% CI: 16.9-19.2). The best risk model demonstrated that recipient creatinine ≥ 2.11 mg/dl [RR = 1.80 (95% CI: 1.56-2.08)], total bilirubin ≥ 2.11 mg/dl [RR = 1.48 (95% CI: 1.27-1.72)], Na+ ≥ 141.01 mg/dl [RR = 1.70 (95% CI: 1.47-1.97)], RNI ≥ 2.71 [RR = 1.64 (95% CI: 1.41-1.90)], body surface ≥ 1.98 [RR = 0.81 (95% CI: 0.68-0.97)] and donor age ≥ 54 years [RR = 1.28 (95% CI: 1.11-1.48)], male gender [RR = 1.19(95% CI: 1.03-1.37)], dobutamine use [RR = 0.54 (95% CI: 0.36-0.82)] and intubation ≥ 6 days [RR = 1.16 (95% CI: 1.10-1.34)] affected the negative outcome rate.

CONCLUSIONS

The current study confirms that both donor and recipient characteristics must be considered in post-transplant outcomes and prognostic scores. Our data demonstrated that recipient characteristics have a greater impact on post-transplant outcomes than donor characteristics. This new concept makes liver transplant teams to rethink about the limits in a MELD allocation system, with many teams competing with each other. The results suggest that although we have some concerns about the donors features, the recipient factors were heaviest predictors for bad outcomes.

Model for end-stage liver disease score and MELD exceptions: 15 years later

The model for end-stage liver disease (MELD) score has been used as an objective scale of disease severity for management of patients with end-stage liver disease; it currently serves as the basis of an urgency-based organ-allocation policy in several countries. Implementation of the MELD score led to a reduction in waiting-list registration and waiting-list mortality and an increase in the number of deceased-donor transplants without adversely affecting long-term outcomes after liver transplantation (LT). The MELD score has been used for management of non-transplant patients with chronic liver disease. MELD exceptions serve as a mechanism to advance the needs of subsets of patients with liver disease not adequately addressed by MELD-based organ allocation. Several models have been proposed to refine and improve the MELD score as the environment within which it operates continues to evolve toward transplantation for sicker patients. The MELD score continues to serve and be used as a template to improve upon as an objective gauge of disease severity and as a metric enabling optimization of allocation of scarce donor organs for LT.

Intravenous immunoglobulins in liver transplant patients: Perspectives of clinical immune modulation

Shortage of appropriate donor grafts is the foremost current problem in organ transplantation. As a logical consequence, waiting times have extended and pretransplant mortality rates were significantly increasing. The implementation of a priority-based liver allocation system using the model of end-stage liver disease (MELD) score helped to reduce waiting list mortality in liver transplantation (LT). However, due to an escalating organ scarcity, pre-LT MELD scores have significantly increased and liver recipients became more complex in recent years. This has finally led to posttransplant decreasing survival rates, attributed mainly to elevated rates of infectious and immunologic complications. To meet this challenging development, an increasing number of extended criteria donor grafts are currently accepted, which may, however, aggravate the patients’ infectious and immunologic risk profiles. The administration of intravenous immunoglobulins (IVIg) is an established treatment in patients with immune deficiencies and other antibody-mediated diseases. In addition, IVIg was shown to be useful in treatment of several disorders caused by deterioration of the cellular immune system. It proved to be effective in preventing hyperacute rejection in highly sensitized kidney and heart transplants. In the liver transplant setting, the administration of specific Ig against hepatitis B virus is current standard in post-LT antiviral prophylaxis. The mechanisms of action of IVIg are complex and not fully understood. However, there is increasing experimental and clinical evidence that IVIg has an immuno-balancing impact by a combination of immuno-supporting and immuno-suppressive properties. It may be suggested that, especially in the context of a worsening organ shortage with all resulting clinical implications, liver transplant patients should benefit from immuno-regulatory capabilities of IVIg. In this review, perspectives of immune modulation by IVIg and impact on outcome in liver transplant patients are described.

Long-term use of antibiotics and proton pump inhibitors predict development of infections in patients with cirrhosis

BACKGROUND & AIMS

Bacterial infections, particularly repeated infections, are significant causes of morbidity and mortality among patients with cirrhosis. We investigated and characterized risk factors for repeat infections in these patients.

METHODS

In a prospective study, we collected data from 188 patients hospitalized with cirrhosis and infections and enrolled in the North American Consortium for the Study of End-Stage Liver Disease (12 centers). Patients were followed up for 6 months after hospital discharge and data were analyzed on type of infections and factors associated with subsequent infections.

RESULTS

Six months after hospital discharge, 14% of subjects had received liver transplants, 27% died, and 59% were alive without liver transplantation. After discharge, 45% had subsequent infections, but only 26% of the subsequent infections occurred at the same site. Compared with patients not re-infected, patients with repeat infections were older and a higher proportion used proton pump inhibitors (PPIs) (P = .006), rifaximin (P < .001), or prophylactic therapy for spontaneous bacterial peritonitis (SBP) (P < .001). Logistic regression showed that SBP prophylaxis (odds ratio [OR], 3.44; 95% confidence interval [CI], 1.56-7.63), PPI use (OR, 2.94; 95% CI, 1.39-6.20), SBP at hospital admission (OR, 0.37; 95% CI, 0.15-0.91), and age (OR, 1.06; 95% CI, 1.02-1.11) were independent predictors of subsequent infections.

CONCLUSIONS

Patients hospitalized with cirrhosis and infections are at high risk for subsequent infections, mostly at different sites, within 6 months of index infection resolution. Those at highest risk include previously infected older patients receiving PPIs and/or SBP prophylaxis, although these associations do not prove that these factors cause the infections. New strategies are needed to prevent infections in patients with cirrhosis.

[Complication management after liver transplantation. Increasing patient safety by standardized approach and interdisciplinary cooperation]

The interdisciplinary management of postoperative complications in liver transplantation is of extreme importance. Due to organ shortage and prioritization of the most severely ill recipients in the model for end-stage liver disease (MELD)-based allocation, both donor and recipient associated morbidity are increasing. An interdisciplinary, structured monitoring concept is essential for the timely identification and specific treatment of postoperative complications. Interdisciplinary clinical rounds, laboratory testing and Doppler ultrasound monitoring of the graft perfusion are as important as comprehensive anti-infection prophylaxis and immunosuppression. Arterial perfusion disorders of any kind, biliary complications and postoperative fluid accumulation demand individualized therapeutic concepts. In summary, the success of liver transplantation depends on the communication and coordinated interdisciplinary cooperation of all disciplines involved.

Circulating gamma-glutamyltransferase fractions in cirrhosis

BACKGROUND & AIMS

Four gamma-gultamyltransferases (GGT) fractions (b-, m-, s-, and f-GGT) have been identified in human plasma and their concentrations and ratios vary in different pathological conditions. To assess the behaviour of fractional GGT in cirrhotic patients evaluated for liver transplantation.

METHODS

This was a single-centre, cross-sectional study; GGT fractions were determined by gel-filtration chromatography.

RESULTS

264 cirrhotic patients (215 males; median age 54.5 years) were included and compared against a group of 200 healthy individuals (100 males; median age 41.5). Median (25th-75th percentile) total and fractional GGT were higher in cirrhotics, with s-GGT showing the greatest increase [36.6 U/L (21.0-81.4) vs. 5.6 U/L (3.2-10.2), P<0.0001], while the median b-GGT/s-GGT ratio was lower in cirrhotics than in healthy controls [0.06 (0.04-0.10)] vs. 0.28 (0.20-0.40), P<0.0001]. The ratio showed higher diagnostic accuracy (ROC-AUC, 95% CI: 0.951, 0.927-0.969) then either s-GGT (0.924, 0.897-0.947; P<0.05) or total GGT (0.900, 0.869-0.925; P<0.001). The diagnostic accuracy of the ratio was maintained (0.940, 0.907-0.963) in cirrhotic patients (n=113) with total GGT values within the reference range. The s-GGT fraction consisted of two components, with one (s2-GGT) showing a significant positive correlation with serum aspartate aminotransferases, alanine aminotransferase, lactate dehydrogenases (LDH), alkaline phosphatases and bilirubin, and negative with albumin. The b-GGT fraction showed a positive correlation with albumin, fibrinogen, and platelet counts, and negative with international normalized ratio, bilirubin and LDH.

CONCLUSIONS

The ratio performs as a sensitive biomarker of the liver parenchymal rearrangement, irrespective of aetiology of cirrhosis and presence of hepatocellular carcinoma, even in patients with total GGT values within the reference range.

Explanted diseased livers - a possible source of metabolic competent primary human hepatocytes

Being an integral part of basic, translational and clinical research, the demand for primary human hepatocytes (PHH) is continuously growing while the availability of tissue resection material for the isolation of metabolically competent PHH remains limited. To overcome current shortcomings, this study evaluated the use of explanted diseased organs from liver transplantation patients as a potential source of PHH. Therefore, PHH were isolated from resected surgical specimens (Rx-group; n = 60) and explanted diseased livers obtained from graft recipients with low labMELD-score (Ex-group; n = 5). Using established protocols PHH were subsequently cultured for a period of 7 days. The viability and metabolic competence of cultured PHH was assessed by the following parameters: morphology and cell count (CyQuant assay), albumin synthesis, urea production, AST-leakage, and phase I and II metabolism. Both groups were compared in terms of cell yield and metabolic function, and results were correlated with clinical parameters of tissue donors. Notably, cellular yields and viabilities were comparable between the Rx- and Ex-group and were 5.3±0.5 and 2.9±0.7×10⁶ cells/g liver tissue with 84.3±1.3 and 76.0±8.6% viability, respectively. Moreover, PHH isolated from the Rx- or Ex-group did not differ in regards to loss of cell number in culture, albumin synthesis, urea production, AST-leakage, and phase I and II metabolism (measured by the 7-ethoxycoumarin-O-deethylase and uracil-5′-diphosphate-glucuronyltransferase activity). Likewise, basal transcript expressions of the CYP monooxygenases 1A1, 2C8 and 3A4 were comparable as was their induction when treated with a cocktail that consisted of 3-methylcholantren, rifampicin and phenobarbital, with increased expression of CYP 1A1 and 3A4 mRNA while transcript expression of CYP 2C8 was only marginally changed. In conclusion, the use of explanted diseased livers obtained from recipients with low labMELD-score might represent a valuable source of metabolically competent PHH which are comparable in viability and function to cells obtained from specimens following partial liver resection.

Prediction of postoperative mortality in liver transplantation in the era of MELD-based liver allocation: a multivariate analysis

BACKGROUND AND AIMS

Liver transplantation is the only curative treatment for end-stage liver disease. While waiting list mortality can be predicted by the MELD-score, reliable scoring systems for the postoperative period do not exist. This study's objective was to identify risk factors that contribute to postoperative mortality.

METHODS

Between December 2006 and March 2011, 429 patients underwent liver transplantation in our department. Risk factors for postoperative mortality in 266 consecutive liver transplantations were identified using univariate and multivariate analyses. Patients who were <18 years, HU-listings, and split-, living related, combined or re-transplantations were excluded from the analysis. The correlation between number of risk factors and mortality was analyzed.

RESULTS

A labMELD ≥20, female sex, coronary heart disease, donor risk index >1.5 and donor Na+>145 mmol/L were identified to be independent predictive factors for postoperative mortality. With increasing number of these risk-factors, postoperative 90-day and 1-year mortality increased (0-1: 0 and 0%; 2: 2.9 and 17.4%; 3: 5.6 and 16.8%; 4: 22.2 and 33.3%; 5-6: 60.9 and 66.2%).

CONCLUSIONS

In this analysis, a simple score was derived that adequately identified patients at risk after liver transplantation. Opening a discussion on the inclusion of these parameters in the process of organ allocation may be a worthwhile venture.