Liver transplantation: from Child to MELD

Intraoperative systemic biomarkers predict post-liver transplantation acute kidney injury

OBJECTIVE

Liver transplant (LT) is a definitive therapeutic option for patients with chronic liver disease. However, acute kidney injury after LT (post-LT AKI) is a frequent complication that may lead to graft dysfunction and decrease life expectancy. Delay in AKI detection by traditional biomarkers boosted research with new biomarkers for post-LT AKI as neutrophil gelatinase-associated lipocalin (NGAL) and syndecan-1. We aim to evaluate associations of intraoperative systemic NGAL and syndecan-1 levels with post-LT AKI.

METHODS

This is a prospective study conducted in 46 patients selected for LT. Patients were evaluated preoperatively and blood samples were collected intraoperatively: T1 (after induction of anesthesia), T2 (anhepatic phase) and T3 (2 h after reperfusion of the graft).

RESULTS

The mean age was 54 ± 12 years and 60% were male. Post-LT AKI was observed in 24 (52%) patients of which 12% needed dialysis. Serum NGAL and syndecan-1 increased along surgical phases. Mostly, increment values of serum NGAL of T2 to T3 and syndecan-1 at T3 were importantly associated with post-LT AKI. Into a multivariate model with model for end-stage liver disease score, age, gender, warm ischemia, cold ischemia and surgery time, syndecan-1 levels at T3 remains capable to predict post-LT AKI. Serum NGAL had significance only with increment values calculated by the ratio of 'T3/T2'. Finally, serum syndecan-1 at T3 had a better diagnostic performance in receiver operating characteristic curve analysis.

CONCLUSION

Serum syndecan-1 levels in 2 h after reperfusion were most useful in early post-LT AKI diagnosis and may be used to construct new risk groups in this context.

Preoperative evaluation of the degree of liver fibrosis based on matter-element analysis using serological indicators in patients with hepatocellular carcinoma

Evaluation of the degree of liver fibrosis is an important basis for the clinical diagnosis and treatment of patients with hepatocellular carcinoma (HCC). It is meaningful to make a preoperative evaluation with non-invasive methods. In the current study, 12 commonly used preoperative serological indicators from 161 HCC patients with different degree of liver fibrosis were collected retrospectively, and 8 of the indicators (ALB, PA, TBil, INR, AST, GGT, ALP, and PT) were ultimately used in matter-element analysis to create a formula. The relationship between those results and the histological sub-classification of the Laennec liver fibrosis scoring system was analyzed. The calculated value of R from this formula will indicate the differing degree of liver fibrosis in a patient: i) the value of 0.802 ≤ R < 1 indicates the early stage of liver cirrhosis, which corresponds to Laennec stages 0-3; ii) the value of 0.752 ≤ R < 0.802 indicates the mild stage of liver cirrhosis, which corresponds to Laennec stage 4A; iii) the value of 0.698 ≤ R < 0.752 indicates the moderate stage of liver cirrhosis, which corresponds to Laennec stage 4B; and iv) the value of 0.444 ≤ R < 0.698 indicates the severe stage of liver cirrhosis, which corresponds to Laennec stage 4C. The hope is that this formula for preoperative evaluation of the degree of liver fibrosis using non-invasive methods would be useful in the clinical diagnosis and treatment of patients with HCC in the future.

A review of differences in cirrhosis between men and women and characteristics of cirrhosis in females

There are differences in the disease susceptibility, natural history of liver disease, complications and treatment response between females and males with cirrhosis. Pre-menopausal status for female patients is protective against viral hepatitis C, non-alcoholic steatohepatitis and primary biliary cirrhosis. Smoking accompanied with drinking is a strong risk factor for cirrhosis and malignancies in women with chronic liver disease. Pregnancy increases the incidence of variceal hemorrhage and hepatic encephalopathy in patients with cirrhosis. The choice of contraceptive measures between patients with liver cirrhosis and normal people is the same. The selection of drugs and surgical treatment in female patients with liver cirrhosis before and after pregnancy complications have obvious differences. The organ distribution of model for end-stage liver disease (MELD) scoring system is detrimental to female patients, but the introduction of new drugs for viral hepatitis C is expected to change this difference.

In vitro hepatic trans-differentiation of human mesenchymal stem cells using sera from congestive/ischemic liver during cardiac failure

Cellular therapy for end-stage liver failures using human mesenchymal stem cells (hMSCs)-derived hepatocytes is a potential alternative to liver transplantation. Hepatic trans-differentiation of hMSCs is routinely accomplished by induction with commercially available recombinant growth factors, which is of limited clinical applications. In the present study, we have evaluated the potential of sera from cardiac-failure-associated congestive/ischemic liver patients for hepatic trans-differentiation of hMSCs. Results from such experiments were confirmed through morphological changes and expression of hepatocyte-specific markers at molecular and cellular level. Furthermore, the process of mesenchymal-to-epithelial transition during hepatic trans-differentiation of hMSCs was confirmed by elevated expression of E-Cadherin and down-regulation of Snail. The functionality of hMSCs-derived hepatocytes was validated by various liver function tests such as albumin synthesis, urea release, glycogen accumulation and presence of a drug inducible cytochrome P450 system. Based on these findings, we conclude that sera from congestive/ischemic liver during cardiac failure support a liver specific microenvironment for effective hepatic trans-differentiation of hMSCs in vitro.

Clinical significance of a scoring formula of liver injury for the preoperative evaluation of patients with liver cirrhosis

OBJECTIVE

The aim of this study was to establish a clinical scoring formula of liver injury (SFLI) using the matter element analysis method, in order to provide the necessary information for the preoperative assessment and treatment of liver cirrhosis in clinical practice.

MATERIALS AND METHODS

We collected preoperative information for 12 serum biochemical markers (ALB, PA, TBil, SCr, INR, ALT, AST, γ-GT, ALP, PT, APTT, and TT) from patients with liver cirrhosis, statistically analyzed the relationship between the serum biochemical markers and the extent of liver injury, and obtained the liver injury scoring formula using the matter element analysis method.

RESULTS

In our formula, the serum biochemical markers of patients with different degrees of liver cirrhosis damage led to different R-values, which represented the severity of the disease and the liver functional reserve. R=1 indicates that the liver tissue is normal; 0.770≤R<1 indicates that the liver is in the early stage of cirrhosis (SFLI I stage); 0.712≤R<0.770 indicates that the liver is in the intermediate state of compensated cirrhosis and decompensated cirrhosis (SFLI I+ stage); 0.629≤R<0.712 indicates that the liver is in the decompensated cirrhosis stage with ascites (SFLI II stage); 0.401≤R<0.629 indicates that the liver is in the stage of severely decompensated cirrhosis with ascites, and patients present with varying degrees of hepatic encephalopathy, hepatic coma, and other complications.

CONCLUSION

The SFLI that we constructed can sensitively and accurately reflect the conditions of liver cirrhosis damage and liver functional reserve.

APACHE IV is superior to MELD scoring system in predicting prognosis in patients after orthotopic liver transplantation

This study aims to compare the efficiency of APACHE IV with that of MELD scoring system for prediction of the risk of mortality risk after orthotopic liver transplantation (OLT). A retrospective cohort study was performed based on a total of 195 patients admitted to the ICU after orthotopic liver transplantation (OLT) between February 2006 and July 2009 in Guangzhou, China. APACHE IV and MELD scoring systems were used to predict the postoperative mortality after OLT. The area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow C statistic were used to assess the discrimination and calibration of APACHE IV and MELD, respectively. Twenty-seven patients died during hospitalization with a mortality rate of 13.8%. The mean scores of APACHE IV and MELD were 42.32 ± 21.95 and 18.09 ± 10.55, respectively, and APACHE IV showed better discrimination than MELD; the areas under the receiver operating characteristic curve for APACHE IV and MELD were 0.937 and 0.694 (P < 0.05 for both models), which indicated that the prognostic value of APACHE IV was relatively high. Both models were well-calibrated (The Hosmer-Lemeshow C statistics were 1.568 and 6.818 for APACHE IV and MELD, resp.; P > 0.05 for both). The respective Youden indexes of APACHE IV, MELD, and combination of APACHE IV with MELD were 0.763, 0.430, and 0.545. The prognostic value of APACHE IV is high but still underestimates the overall hospital mortality, while the prognostic value of MELD is poor. The function of the APACHE IV is, thus, better than that of the MELD.

Update in liver transplantation

PURPOSE OF REVIEW

Successful transplant outcomes require optimal patient selection and timing. This review will update clinicians with current status and challenges in liver transplantation. Currently, the major limitation facing liver transplant centers is the shortage of organs. The limited availability of organs has led to long waiting periods for liver transplantation and consequently many patients become seriously ill or die while on the waiting list.

RECENT FINDINGS

This has major implications in the selection of patients, as well as the timing of transplant, for optimal use of these scarce organs. Indications and contraindications have changed slightly over the years and will be reviewed in this article.

SUMMARY

Timing for transplantation has changed more dramatically in the recent years because major changes to organ allocation systems have been undertaken to provide clinicians with a better way to prioritize patients for liver transplant.

Early lactate clearance as a reliable predictor of initial poor graft function after orthotopic liver transplantation

BACKGROUND

Initial poor graft function (IPGF) following orthotopic liver transplantation is a major determinant of postoperative survival and morbidity. Lactate clearance is a good marker of liver function. In this study, we investigated the clinical utility of early lactate clearance as an early and accurate predictor for IPGF following liver transplantation.

METHODS

This was a prospective observational study of 222 patients referred to the surgical intensive care unit (SICU) after orthotopic liver transplantation. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) >1500 IU/L within 72 hours after orthotopic liver transplantation. Early lactate clearance was defined as lactate at SICU presentation (hour 0) minus lactate at hour 6, divided by lactate at SICU presentation. The model for end-stage liver disease (MELD) score, Child-Pugh score and laboratory data including AST, ALT, total bilirubin (TB) and prothrombin time (PT) were recorded at SICU presentation and compared between the non-IPGF and IPGF groups. Receiver operating characteristic (ROC) curves were plotted to measure the performance of early lactate clearance, MELD score, Child-Pugh score, TB and PT.

RESULTS

IPGF occurred in 45 of the 222 patients (20.3%). The early lactate clearance in the non-IPGF group was markedly higher than that in the IPGF group (43.2+/-13.8% vs 13.4+/-13.7% P<0.001). The optimum cut-off value for early lactate clearance predicting IPGF was 24.8% (sensitivity 95.5%, specificity 88.9%). The area under the curve of the ROC was 0.961, which was significantly superior to MELD score, Child-Pugh score, TB and PT. Patients with early lactate clearance ≤24.8% had a higher IPGF rate (OR=169) and a higher risk of in-hospital mortality (OR=3.625).

CONCLUSIONS

Early lactate clearance can serve as a prompt and accurate bedside predictor of IPGF. Patients with early lactate clearance less than 24.8% are associated with a higher incidence of IPGF.

Effect of the aetiology and severity of liver disease on oral health and dental treatment prior to transplantation

Elimination of dental infection foci has been recommended before liver transplantation (LT) because lifelong immunosuppression may predispose to infection spread. Association between pre-LT oral health and the aetiology and severity of chronic liver disease (CLD) was investigated retrospectively. A total of 212 adult patients (median age 51.1) who had received LT during 2000-2006 in Finland were included. Their oral health had been pre-operatively examined. Patients were divided into seven different CLD groups. Common indications for LT were primary sclerosing cholangitis (PSC 25.5%), alcohol cirrhosis (ALCI 17.5%) and primary biliary cirrhosis (PBC 14.6%). Patients were also categorized by the Model for End stage Liver Disease (MELD) scoring system. Medical, dental and panoramic jaw x-ray data were analysed between groups. PBC patients had the lowest number of teeth with significant difference to PSC patients (19.7 vs. 25.6, P < 0.005, anova, t-test). ALCI patients had the highest number of tooth extractions with significant difference in comparison to PSC patients (5.6 vs. 2.5, P < 0.005). Lower MELD score resulted in fewer tooth extractions but after adjusting for several confounding factors, age was the most important factor associated with extractions (P < 0.005). The aetiology of CLD associated with the oral health status and there was a tendency towards worse dental health with higher MELD scores.

Evidence-based development of liver allocation: a review

Liver transplantation has undergone a rapid evolution from a high-risk experimental procedure to a mainstream therapy for thousands of patients with a wide range of hepatic diseases. Its increasing success has been accompanied by progressive imbalance between organ donor supply and the patients who might benefit. Where demand outstrips supply in transplantation, a system of organ allocation is inevitably required to make the wisest use of the available, but scarce, organs. Early attempts to rationally allocate donor livers were particularly hampered by lack of available and suitable data, leading to imperfect solutions that created or exacerbated inequities in the system. The advent and maturation of evidence-based predictors of waiting list mortality risk led to more objective criteria for liver allocation, aided by the increasing availability of data on large numbers of patients. Until now, the vast majority of allocation systems for liver transplantation have relied on estimation of waiting list mortality. Evidence-based allocation systems that incorporate measures of post-transplant outcomes are conceptually attractive and these transplant benefit-based allocation systems have been developed, modeled, and subjected to computer simulation. Future implementations of benefit-based liver allocation await continued refinement and additional debate in the transplant community.

Adult liver transplantation in the USA

PURPOSE OF REVIEW

To provide the nontransplant clinician with a basic understanding of the liver transplant process.

RECENT FINDINGS

Since its inception, the technique of liver transplantation and patient management has evolved considerably. We present an up-to-date overview of the evaluation of the transplant recipient and the listing and timing of transplant. We conclude with a brief summary of long-term complications, which should be considered when caring for the posttransplant patient.

SUMMARY

Liver transplantation is the only definitive treatment option for patients dying of liver failure. The growing population of patients with liver disease means that more transplants will be performed. As these patients now live longer lives, it is crucial that clinicians have a basic understanding of the process and outcomes.

Disparities in organ allocation and access to liver transplantation in the USA

Liver transplantation has become the standard of care for the treatment of chronic liver disease. In 1986, the United Network for Organ Sharing (UNOS) was formed to ensure the just and equitable allocation of donor livers. At the time, UNOS decided to use the Childs-Turcotte-Pugh scoring system to determine the degree of liver disease in potential transplant patients. Unfortunately, it was shown that the Childs-Turcotte-Pugh system was easily manipulated and did not provide equal access to donor organs. Owing to this fact, the Model of End Stage Liver Disease (MELD) score was instituted by UNOS in February 2002. While the institution of MELD has shown an improvement in organ allocation and outcomes, disparities still exist. This article discusses UNOS and the MELD allocation system as well as the racial, geographic and gender disparities that occur despite the institution of the MELD system.