Liver transplantation

Utility of Framingham Score for Optimizing Preoperative Evaluation Among Patients Undergoing Liver Transplant Evaluation

BACKGROUND

Cardiac testing of candidates for liver transplant (LT) requires balancing risks and benefits of cardiac procedures. The goal of this study was to evaluate the utility of the Framingham score (FS) for optimizing preoperative risk stratification for coronary artery disease (CAD).

METHODS

In this single-center retrospective study of 615 adults undergoing LT evaluation from 2016 to 2019, data of preoperative evaluation, post-LT 1-year mortality, and post-LT cardiac events were reviewed. Patients >30 years of age with normal echocardiogram underwent FS calculation. Elevated FS (≥35%) patients were triaged to undergo angiogram for CAD evaluation; FS <35% patients underwent stress testing as initial CAD evaluation.

RESULTS

Of 615 patients referred for LT, 481 underwent cardiac testing. Ninety-five were excluded from the FS pathway because of age, abnormal baseline echocardiogram, or known CAD. Of the remaining 386 patients in the FS pathway, 342 had a low FS and 44 had a high FS. In patients with low FS, 90% underwent stress testing as initial test; 16% underwent invasive testing at some time. In those with elevated FS, 59% underwent invasive testing as initial test. Listing rate and posttransplant outcomes were similar between patients with low and high FS.

CONCLUSION

We demonstrated the feasibility of a simple algorithmic evaluation process using FS for optimizing pre-LT risk stratification for CAD. Although exceptions to the protocol occur, the proposed protocol allows for a streamlined approach by prioritizing testing based on cardiac risk. This approach may maximize diagnostic yield while limiting invasive procedures.

Anticoagulant Management and Synthesis of Hemostatic Proteins during Machine Preservation of Livers for Transplantation

Liver transplantation remains the only curative treatment for patients with end-stage liver disease. Despite a steadily increasing demand for suitable donor livers, the current pool of donor organs fails to meet this demand. To resolve this discrepancy, livers traditionally considered to be of suboptimal quality and function are increasingly utilized. These marginal livers, however, are less tolerant to the current standard cold preservation of donor organs. Therefore, alternative preservation methods have been sought and are progressively applied into clinical practice. Ex situ machine perfusion is a promising alternative preservation modality particularly for suboptimal donor livers as it provides the ability to resuscitate, recondition, and test the viability of an organ prior to transplantation. This review addresses the modalities of machine perfusion currently being applied, and particularly focuses on the hemostatic management employed during machine perfusion. We discuss the anticoagulant agents used, the variation in dosage, and administration, as well as the implications of perfusion for extended periods of time in terms of coagulation activation associated with production of coagulation factors during perfusion. Furthermore, in regard to viability testing of an organ prior to transplantation, we discuss the possibilities and limitations of utilizing the synthesis of liver-derived coagulation factors as potential viability markers.

Different approaches for transformation of mesenchymal stem cells into hepatocyte-like cells

Due to the prominent role of the liver in the body and detoxification, its functionality can be affected in an irreversible manner by diseases. This phenomenon renders the liver to stop working, leading to morbidity and mortality. Therefore, liver transplantation is the only way to tackle this issue.In order to compensate for the lack of adequate healthy liver tissue for transplantation, therapeutic approaches such as hepatocyte transplantation have been proposed as an alternative. Recognizing the fact that mesenchymal stem cells are adult stem cells with the capacity to differentiate into several cell types, different methods have been invented to produce hepatocyte-like cells from mesenchymal stem cells. They can be divided into three main categories, such as addition of cytokines and growth factors, genetic modifications, and adjustment of microenvironment as well as physical parameters.In this review, we attempted to introduce diverse efficient methods for differentiating mesenchymal stem cells and their capability for transformation into hepatocyte-like cells.

Therapeutic applications of adipose-derived mesenchymal stem cells on acute liver injury in canines

In this study, canine adipose-derived mesenchymal stem cells (cADSCs) therapeutic potential was investigated in artificially induced acute liver injury model by CCl₄ in canines. The primary cADSCs cells were cultured and then intravenously administered into the canine animal model. Six cross-breed dogs were divided into three groups including blank control group, CCl₄ model group, CCl₄ induced cADSCs transplantation group. The results showed that after intraperitoneal injection of CCl₄ solution, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and Albumin (ALB) in peripheral blood of experimental canines confirmed the correct induction of acute liver injury. Moreover, the liver structure showed clear macroscopic damage. The cADSCs were homed in the liver of the administered animals. The AST, ALT and ALB in the peripheral blood rapidly decreased. H&E and PAS histological evaluation showed that both the structure of canine liver tissue and the ability to synthesize hepatic glycogen could be restored to the control level after cADSCs transplantation. Therefore, cADSCs can play a therapeutic role in the recovery of liver injury. Overall, this study demonstrates that the primary cADSCs transplantation into the acute liver injury model induced by intravenous injection can play a certain therapeutic role in the recovery of liver in canines. These results may provide a new treatment idea for acute liver disease in pets clinically.

Outcomes of Patients Who Undergo Cardiac Surgical Procedures After Liver Transplantation

BACKGROUND

There is a paucity of information available regarding the impact of cardiac surgical procedures on patients who have undergone previous liver transplantation. The primary purpose of this study was to ascertain the survival rate and predictors of death in this specific patient population.

METHODS

This retrospective cohort study consisted of a consecutive series of patients with a functioning liver allograft who subsequently underwent cardiac surgical procedures between January 1991 and December 2012. The optimal Model for End-Stage Liver Disease (MELD) score for predicting late death was identified using receiver operating characteristic curve analysis. Risk of postoperative death was determined by parametric hazard analysis.

RESULTS

Between January 1991 and December 2012, 43 patients (median age, 60 years) underwent cardiac surgical procedures after liver transplantation. The median interval between liver transplant and cardiac operation was 63 months (range, 1.1 to 217 months). Three operative deaths and 24 late deaths occurred. Receiver operating characteristic curve analysis identified the optimal preoperative and postoperative MELD score cut points for predicting late death as greater than 13.8 (area under the curve = 0.674) and greater than 17 (area under the curve = 0.633), respectively. Patients with a preoperative MELD score of 13.8 or less had significantly greater survival rates than those with a MELD score greater than 13.8 (p = 0.028); patients with a postoperative MELD score of 17 of less had significantly greater survival rates than those with a MELD score greater than 17 (p < 0.001). Multivariate parametric hazard analysis identified postoperative peak creatinine level as a statistically significant predictor of death (relative risk, 1.8; p = 0.01). The 1-, 5-, and 10-year Kaplan-Meier survival rates were 90%, 51%, and 35%, respectively; postoperative mortality rates followed a constant phase model with a hazard of death of 10% per year.

CONCLUSIONS

Cardiac surgical procedures can be performed with acceptable short-term and long-term outcomes in liver transplant recipients. Elevated preoperative and postoperative MELD scores and postoperative peak creatinine level may portend death in this cohort. There is a constant hazard of death of 10% per year.

Hyperhomocysteinemia is associated with severity of cirrhosis and negative impact after liver transplantation

BACKGROUND & AIMS

Hyperhomocysteinemia constitutes an independent risk factor for thrombosis and cellular injury promoted by oxidative stress. The clinical significance of hyperhomocysteinemia in cirrhosis and outcomes post-liver transplantation is poorly documented. In this study, we aimed to determine the prevalence of hyperhomocysteinemia in cirrhosis, evaluate its association with thrombosis and severity of liver disease, and its impact on survival after liver transplantation.

METHODS

We analysed 450 patients with cirrhosis who received a liver transplant between 2001 and 2010. Data were recovered from medical charts and homocysteine serum levels were determined before liver transplantation in all patients.

RESULTS

Median age was 53 years (range, 18-72 years) and 308 patients were males (68%). Cirrhosis aetiology was hepatitis C (37%), autoimmune liver disease (22%), alcohol (16%) and others (25%). The median homocysteine level was 11 μmol/L (range, 4-221 μmol/L) and 165 patients (37%) had hyperhomocysteinemia. The MELD (23 ± 10 vs. 20 ± 9 points, P < 0.001), and Child-Pugh (11 ± 2 vs. 9 ± 2 points, P < 0.001) scores were higher in patients with hyperhomocysteinemia. Episodes of thrombosis occurred in 91 patients (20%), but there was no significant difference in patients with or without hyperhomocysteinemia (19 vs. 21%, P = 0.6). Hyperhomocysteinemia was associated with reduced graft (105 ± 4 vs. 119 ± 2 months; P = 0.005), and patient survival (125 ± 33 vs. 131 ± 2 months; P = 0.006).

CONCLUSIONS

Hyperhomocysteinemia is frequently present in patients with cirrhosis and is associated with severe liver disease and reduced graft and patient survival after liver transplantation. The negative impact hyperhomocysteinemia has on graft and patient survival is not related to thrombosis.

Immunological aspects in late phase of living donor liver transplant patients: usefulness of monitoring peripheral blood CD4+ adenosine triphosphate activity

Aim. To evaluate whether the combination of the peripheral blood CD4+ adenosine triphosphate activity (ATP) assay (ImmuKnow assay: IMK assay) and cytochrome P450 3A5 (CYP3A5) genotype assay is useful for monitoring of immunological aspects in the patient followup of more than one year after living donor liver transplantation (LDLT). Methods. Forty-nine patients, who underwent LDLT more than one year ago, were randomly screened by using IMK assay from January 2010 to December 2011, and the complete medical records of each patient were obtained. The CYP3A5 genotypes were examined in thirty-nine patients of them. Results. The mean ATP level of the IMK assay was significantly lower in the patients with infection including recurrence of hepatitis C (HCV) (n = 10) than in those without infection (n = 39): 185 versus 350 ng/mL (P < 0.001), while it was significantly higher in the patients with rejection (n = 4) than in those without rejection (n = 45): 663 versus 306 ng/mL (P < 0.001). The IMK assay showed favorable sensitivity/specificity for infection (0.909/0.842) as well as acute rejection (1.0/0.911). CYP3A5 genotypes in both recipient and donor did not affect incidence of infectious complications. Conclusions. In the late phase of LDLT patients, the IMK assay is very useful for monitoring immunological aspects including bacterial infection, recurrence of HCV, and rejection.

Reduction of galectin-3 expression and liver fibrosis after cell therapy in a mouse model of cirrhosis

BACKGROUND AIMS

Cirrhosis, end-stage liver disease, is caused by different mechanisms of injury, associated with persistent inflammation. Galectin-3 is an important regulator of fibrosis that links chronic inflammation to fibrogenesis. We investigated the role of bone marrow cell (BMC) transplantation in chronic inflammation and hepatic fibrosis.

METHODS

Liver cirrhosis was induced by administration of carbon tetrachloride and ethanol to wild-type C57BL/6 or bone marrow chimeric mice. Bone marrow chimeras were generated by lethal irradiation and transplantation with BMC obtained from green fluorescent protein (GFP(+) )donors. Wild-type cirrhotic mice were transplanted with BMC without irradiation. Livers from chimeras and cirrhotic transplanted mice were obtained for evaluation of inflammation, fibrosis and regulatory factors [galectin-3, matrix metallopeptidase (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 and transforming growth factor (TGF)-β].

RESULTS

The development of cirrhosis was associated with increased expression of galectin-3 by F4/80(+) cells and intense migration of BMC to the liver. Furthermore, when transplanted after the establishment of cirrhosis, BMC also migrated to the liver and localized within the fibrous septa. Two months after BMC therapy, cirrhotic mice had a significant reduction in liver fibrosis and expression of type I collagen. We did not find any difference in levels of TGF-β, TIMP-1 and MMP-9 between saline and BMC groups. However, the numbers of inflammatory cells, phagocytes and galectin-3(+) cells were markedly lower in the livers of cirrhotic mice treated with BMC.

CONCLUSIONS

Our results demonstrate an important role for BMC in the regulation of liver fibrosis and that transplantation of BMC can accelerate fibrosis regression through modulatory mechanisms.

Epidemiology and risk factors for late infection in solid organ transplant recipients

BACKGROUND

Information concerning the risk factors and outcome of late infection (LI) after solid organ transplantation (SOT) still remains scarce.

METHODS

We prospectively analyzed all patients undergoing SOT from July 2003 to March 2008, who survived the first 6 months after surgery and with a minimum 1-year follow-up. Risk factors associated with the development of bacterial and cytomegalovirus (CMV) LI and survival were identified.

RESULTS

Overall, 942 SOT recipients (491 kidney, 280 liver, 65 heart, and 106 double transplants) were included. During the study period 147 patients (15.6%) developed 276 episodes of LI (incidence rate, 0.43 per 1000 transplantation-days). Bacteria were the most prevalent etiology (88.0%). Primary sources of infection included urinary tract (36.9%), intra-abdominal (16.7%), and sepsis without source (13.4%). Independent risk factors for late bacterial infection were: age (hazard ratio [HR] [per year] 1.0; 95% confidence interval [CI]: 1.0-1,0), female gender (HR 1.7; 95%CI: 1.1-2.6), anti-hepatitis C virus (HCV) positive serostatus (HR 1.8; 95%CI: 1.1-3.0), chronic allograft dysfunction (HR 3.2; 95%CI: 1.7-6.1), early CMV disease (HR 2.2; 95%CI 1.2-4.1), and early bacterial infection (HR 2.5; 95%CI 1.6-3.8). The occurrence of chronic allograft dysfunction was an independent risk factor for late CMV disease (HR 6.5; 95%CI: 1.7-24.6), whereas immunosuppression based on mammalian target of rapamycin inhibitors protected against the development of late CMV disease (HR 0.3; 95%CI: 0.1-1.0). Cox model selected anti-HCV positive serostatus (adjusted HR [aHR] 2.67; 95%CI: 1.27-5.59), age (aHR [per year] 1.06; 95%CI: 1.02-1.10), and the occurrence of LI (aHR 9.12; 95%CI: 3.90-21.33) as independent factors for mortality.

CONCLUSIONS

LI did not constitute an uncommon complication in our cohort, and patients at risk may benefit from close clinical monitoring.

Hepatic progenitor cells

Liver diseases are associated with a marked reduction in the viable mass of hepatocytes. The most severe cases of liver disease (liver failure) are treated by orthotopic liver transplantation. One alternative to whole organ transplantation for patients with hepatic failure (and hereditary liver disease) is hepatocyte transplantation. However, there is a serious limitation to the treatment of liver diseases either by whole organ or hepatocyte transplantation, and that is the shortage of organ donors. Therefore, to overcome the problem of organ shortage, additional sources of hepatocytes must be found. Alternative sources of cells for transplantation have been proposed including embryonic stem cells, immortalised liver cells and differentiated cells. One other source of cells for transplantation found in the adult liver is the progeny of stem cells. These cells are termed hepatic progenitor cells (HPCs). The therapeutic potential of HPCs lies in their ability to proliferate and differentiate into hepatocytes and cholangiocytes. However, using HPCs as a cell therapy cannot be exploited fully until the mechanisms governing hepatocyte differentiation are elucidated. Here, we discuss the fundamental cellular and molecular elements required for HPC differentiation to hepatocytes.

Increased incidence of early de novo cancer in liver graft recipients treated with cyclosporine: an association with C2 monitoring and recipient age

The goal of this study was to determine the risk factors for de novo cancer after liver transplantation (LTx). Retrospective analyses were performed in 385 LTx patients who underwent transplantation between 1986 and 2007. In total, 50 (13.0%) recipients developed de novo malignancy. The cumulative incidence of de novo cancer at 1, 5, 10, and 15 years after LTx was 2.9% +/- 0.9%, 10.5% +/- 1.8%, 19.4% +/- 3.0%, and 33.6% +/- 6.8%, respectively. The standardized incidence ratio of malignancy in LTx patients compared to the general population was 2.2 (95% confidence interval: 1.6-2.8). After excluding posttransplant lymphoproliferative disorder and skin cancer, patients with de novo cancer had a significantly lower survival rate compared to recipients who remained cancer-free. The identified univariate risk factors for de novo cancer were cyclosporine A (CsA) treatment, time period of LTx, and recipient age. In multivariate analysis, only CsA treatment emerged as an independent risk factor for de novo cancer, which was attributed to more aggressive cancer types. A surprising finding was that CsA treatment specifically enhanced cancer risk in patients who underwent transplantation after 2004, when C(2) monitoring (blood concentration at 2 hours postdose) was introduced. In addition, these patients showed a significantly lower acute rejection rate, which might reflect a more robust immunosuppressive status caused by the CsA-C(2) regimen. When age was considered, only patients < or =50 years had a higher cancer rate when treated with CsA compared to treatment with tacrolimus. Our data suggest that, compared to tacrolimus treatment, CsA treatment with C(2) monitoring or in younger patients of < or =50 years is associated with a higher early de novo cancer risk after LTx.

Prediction of cardiac complications after liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) stresses the cardiovascular system, and cardiac complications after OLT are common.

METHODS

Hundred ninety-seven patients (>or=40 years) who had OLT from 2002 to 2007 were reviewed to identify predictors of cardiac complications within 6 months after transplantation.

RESULTS

Median age was 56 years (40-75 years); 69% men. Reasons for OLT were hepatitis C virus (HCV) 45.5%, alcohol 22%, hepatocellular carcinoma (HCC) 8%, primary biliary cirrhosis 10%, and others 14.5%. Eighty-two patients suffered one or more cardiac complications within 6 months after OLT (pulmonary edema=61 [overt heart failure=7], arrhythmia=13, pulmonary hypertension=7, pericardial effusion=2, and right atrial thrombus=1). Cardiac causes were the leading cause of death (n=5; 23.8% of all mortality). By multivariate analysis, after adjusting for age and sex, independent predictors were adverse intraoperative cardiovascular events (adjusted odds ratio; 95% confidence interval: 5.89, 1.82-19.14), history of cardiac disease (2.42, 0.89-6.6), and i-MELD (integrated model for end-stage liver disease) score (1.08, 1.02-1.14), whereas adverse intraoperative cardiovascular events (5.73, 1.96-16.78) and i-MELD (1.07, 1.01-1.13) predicted pulmonary edema. None of the following variables predicted complications: age, sex, OLT indication, body mass index, blood pressure, alcohol and smoking history, pre-OLT investigations (chest X-ray, electrocardiogram, echocardiography, coronary angiography, pulmonary arterial pressure, and 2-methoxy isobutyl isonitrile scan), immunosuppressive treatment, or intraoperative variables (transfusion amount, cadaveric vs. living graft or cold ischemia and rewarming times).

CONCLUSIONS

Cardiac complications after OLT are common and were the leading cause of death after surgery. Adverse intraoperative cardiovascular events, previous cardiac disease, and advanced liver disease as quantified by i-MELD score predicted postoperative cardiac complications.

Liver-enriched transcription factors are critical for the expression of hepatocyte marker genes in mES-derived hepatocyte-lineage cells

Background

Induction of stem cell differentiation toward functional hepatocytes is hampered by lack of knowledge of the hepatocyte differentiation processes. The overall objective of this project is to characterize key stages in the hepatocyte differentiation process.

Results

We established a mouse embryonic stem (mES) cell culture system which exhibited changes in gene expression profiles similar to those observed in the development of endodermal and hepatocyte-lineage cells previously described in the normal mouse embryo. Transgenic mES cells were established that permitted isolation of enriched hepatocyte-lineage populations. This approach has isolated mES-derived hepatocyte-lineage cells that express several markers of mature hepatocytes including albumin, glucose-6-phosphatase, tyrosine aminotransferase, cytochrome P450-3a, phosphoenolpyruvate carboxykinase and tryptophan 2,3-dioxygenase. In addition, our results show that the up-regulation of the expression levels of hepatocyte nuclear factor-3α, -4α, -6, and CCAAT-enhancer binding protein-β might be critical for passage into late-stage differentiation towards functional hepatocytes. These data present important steps for definition of regulatory phenomena that direct specific cell fate determination.

Conclusion

The mES cell culture system generated in this study provides a model for studying transition between stages of the hepatocyte development and has significant potential value for studying the molecular basis of hepatocyte differentiation in vitro.

Role of cytochrome P450 2C8 and 2J2 genotypes in calcineurin inhibitor-induced chronic kidney disease

OBJECTIVES

The calcineurin inhibitors (CNIs) cyclosporine A (CsA) and tacrolimus (Tac) help prevent allograft rejection but are associated with nephrotoxicity. Cytochrome P450 2C8 (CYP2C8) and CYP2J2 are polymorphic enzymes expressed in the kidney that metabolize arachidonic acid (AA) to epoxyeicosatrienoic acids, promoting kidney homeostasis. This study examined the association between CNI-induced nephrotoxicity in liver transplant patients and CYP2C8 and CYP2J2 polymorphisms.

METHODS

Liver transplantation patients receiving CNIs for at least 3 years were genotyped for CYP2C8*3, CYP2C8*4, CYP2C8 Haplotypes B and C, and CYP2J2*7 and evaluated for nephrotoxicity (serum creatinine > or = 1.6 mg/dl) 3-year post-transplantation. CYP2C8 proteins were also engineered in E. coli and their activity towards AA and inhibition by CNIs was investigated in vitro.

RESULTS

The risk of kidney disease post-transplantation was positively associated with CYP2C8*3 genotype. Odds ratios for all participants carrying at least one CYP2C8*3 allele were significant [odds ratio=2.38 (1.19-4.78)]. Stratification by CNI indicated a significant association between CYP2C8*3 and nephrotoxicity among patients receiving Tac but not CsA. The risk of renal dysfunction was not significantly influenced by CYP2C8*4, CYP2J2*7, or CYP2C8 haplotype B genotypes although inheritance of haplotype C seems to be protective. In vitro, the gene products of CYP2C8*3 and CYP2C8*4 were deficient in AA epoxidation, retaining 26 and 18% of wild-type activity, respectively. Circulating plasma concentrations of CsA and Tac inhibited CYP2C8 wild-type in vitro epoxidation of AA by 17 and 35%, respectively.

CONCLUSION

Inheritance of CYP2C8*3 is associated with a higher risk of developing renal toxicity in patients treated chronically with CNIs, and especially Tac, possibly by reducing formation of kidney protecting vasodilatory epoxyeicosatrienoic acids.

The Influence of Psychosocial Evaluation on Candidacy for Liver Transplantation

Context

Although medical factors clearly dominate the evaluation of appropriateness for liver transplant, psychosocial factors are an important dimension in the evaluation process.

Objective

To understand more about the weight assigned to psychosocial factors in the decision to list patients for liver transplant and about whether such differences create hidden inequities in the transplant allocation system.

Design

We conducted a mail survey of liver transplant surgeons and psychosocial evaluators at busy transplant centers assessing the importance these professionals assigned to psychosocial factors in evaluations for liver transplant candidacy.

Participants

Liver transplant surgeons and psychosocial evaluators from the highest volume liver transplant centers in the United States.

Intervention

Mail survey

Results

Psychosocial evaluators assigned greater importance to availability of transportation, adaptation to stress, and coping skills than did surgeons. Transplant psychosocial evaluators were less likely than transplant surgeons to recommend that a patient with a history of poor social support be listed for liver transplant. We found no correlation between relative weight assigned to psychosocial factors and median wait times at transplant centers. These differences suggest that the relationship between the factors identified by psychosocial evaluators as important and transplant outcomes should be studied. Overall, more research into the predictive and ethical aspects of psychosocial evaluation for liver transplant is needed.

Preformed antibodies detected by cytotoxic assay or multibead array decrease liver allograft survival: role of human leukocyte antigen compatibility

The significance of human leukocyte antigen (HLA) compatibility and preformed antibodies in liver transplantation remains unclear. The objectives of this study were to evaluate, in a single-center cohort comprising 896 liver transplants, whether the degree of donor-recipient compatibility and preformed antibodies modified graft survival. Univariate Kaplan-Meier analysis demonstrated that donor-recipient HLA compatibility had a marginal impact on allograft survival. As for compatibility at individual antigen loci, 2 mismatches at HLA-A conferred a survival advantage in retransplanted allografts (P = 0.011). HLA-B and HLA-DR loci did not play a significant role in outcome in any pathology. The concordance of results on preformed antibodies detected by complement-dependent cytotoxicity (CDC) and a multiple bead assay (Luminex xMAP) showed a strong correlation between both techniques (P < 0.0001). Both CDC-detected and Luminex-detected antibodies were associated with shorter graft survival within the first year post-transplant (P = 0.01 and P = 0.016, respectively). Positive CDC T crossmatches and Luminex-detected HLA class II antibodies played a significant role in decreasing graft survival (P = 0.043 and P = 0.0019 at 1 year, respectively, and P = 0.005 and P = 0.038 at 5 years, respectively). A correlation was also observed between the presence of preformed Luminex-detected class II or Luminex I and II antibodies and allograft rejection (P = 0.001 and P = 0.042, respectively). In conclusion, although HLA typing is not a prerequisite for transplantation, screening of HLA antibodies with Luminex techniques and CDC crossmatch may be useful in the detection of at-risk patients that could benefit from increased surveillance and tailored therapy following transplantation.

Cirrhosis after orthotopic liver transplantation in the absence of primary disease recurrence

Liver allograft cirrhosis is a relatively uncommon complication of liver transplantation. Most cases can be attributed to disease recurrence, particularly recurrent hepatitis C. Little is known about the frequency, etiology, and natural history of liver allograft cirrhosis occurring without evidence of recurrent disease. The aim of the present study was to review the clinicopathological features in this group of patients. We retrospectively reviewed data from all adult patients who were transplanted between 1982 and 2002 and survived >12 months after orthotopic liver transplantation (n = 1,287). Cases of histologically proven cirrhosis were identified from histopathological data entered into the Liver Unit Database. A total of 48 patients (3.7%) developed cirrhosis. In 29 of them, cirrhosis could be attributed to recurrent disease (hepatitis C, 11; hepatitis B, 4; autoimmune hepatitis, 4; primary biliary cirrhosis, 2; primary sclerosing cholangitis, 3; nonalcoholic steatohepatitis, 4; alcoholic liver disease, 1). In 9 of the 19 patients without evidence of disease recurrence, another cause of cirrhosis could be identified (de novo autoimmune hepatitis, 4; biliary complications, 4; acquired hepatitis B, 1). In the remaining 10 cases, the cause of cirrhosis remained unknown; their previous biopsies had shown features of chronic hepatitis of uncertain etiology. Three patients in this group died, and the remaining 7 are alive with good graft function 3-12 years after cirrhosis was first diagnosed. The prevalence of "cryptogenic" posttransplant cirrhosis was significantly higher in patients initially transplanted for fulminant seronegative hepatitis (6%) than in those transplanted for other diseases (0.3%). In conclusion, posttransplant cirrhosis without disease recurrence is uncommon, but it is more frequent in patients transplanted for fulminant seronegative hepatitis. Chronic hepatitis is the most frequent underlying pathological process in cases where the cause of cirrhosis remains uncertain.

Bone marrow cells: the source of hepatocellular carcinoma?

Whether the stem cells or the mature cells are the origination of hepatocellular carcinoma is uncertain. Recently, researches have shown that some cancer stem cells could derive from adult stem cells. Moreover, gastric cancer could originate from bone marrow stem cells. Hematopoiesis and the hepatic environment are known to have a close relationship at the time of hepatic development and systemic diseases. Here we propose a new carcinogenetic model of hepatocellular carcinoma. Chronic liver injury could recruit bone marrow stem cells to the liver. Bone marrow cells take part in liver regeneration by differentiating to oval cells and hepatocytes. Persistent regeneration results in hyperproliferation, an increased rate of transforming mutations. Extracellular matrix remodeling triggers a cascade of events that inhibits the transactivation potential of liver-specific transcription factors, blocks the maturation of stem cells, and then results in hepatocellular carcinoma.

Galectin-3 regulates myofibroblast activation and hepatic fibrosis

Central to fibrogenesis and the scarring of organs is the activation of fibroblasts into matrix-secreting myofibroblasts. We demonstrate that Galectin-3 expression is up-regulated in established human fibrotic liver disease and is temporally and spatially related to the induction and resolution of experimental hepatic fibrosis. Disruption of the Galectin-3 gene blocks myofibroblast activation and procollagen (I) expression in vitro and in vivo, markedly attenuating liver fibrosis. Addition of exogenous recombinant Galectin-3 in vitro reversed this abnormality. The reduction in hepatic fibrosis observed in the Galectin-3(-/-) mouse occurred despite equivalent liver injury and inflammation, and similar tissue expression of TGF-beta. TGF-beta failed to transactivate Galectin-3(-/-) hepatic stellate cells, in contrast with WT hepatic stellate cells; however, TGF-beta-stimulated Smad-2 and -3 activation was equivalent. These data suggest that Galectin-3 is required for TGF-beta mediated myofibroblast activation and matrix production. Finally, in vivo siRNA knockdown of Galectin-3 inhibited myofibroblast activation after hepatic injury and may therefore provide an alternative therapeutic approach to the prevention and treatment of liver fibrosis.

Plasma total homocysteine and cardiovascular risk in patients submitted to liver transplantation

Patients submitted to orthotopic liver transplantation (OLT) show an increased rate of cardiovascular events. OLT subjects have high homocysteine (Hcy) levels, but no data are available on the association of Hcy with cardiovascular events. In a cross-sectional analysis, 230 subjects were studied at least 6 months after OLT (159 on cyclosporine, 71 on tacrolimus). Routine laboratory data and total Hcy were recorded, as well as the history of diabetes, hypertension, dyslipidemia, and overweight. Cardiovascular events occurring in a follow-up of 2-36 months were registered. OLT subjects had higher-than-normal Hcy (median 16.7 micromol/L, range 6.1-171.8) without difference between the 2 immunosuppressive agents. The prevalence of Hcy >15 micromol/L was also similar, and significantly correlated with creatinine levels. A total of 28 arterial events occurred in 25 patients during follow-up (11 in coronary arteries, 10 in peripheral arteries, and 7 in splanchnic arteries). Deep vein thromboses occurred in 2 patients, and splanchnic vein thromboses in 4 patients. Cardiovascular events were frequently associated to high Hcy and hypertension. Cox regression analysis showed that high Hcy was significantly associated with arterial events. The risk of any arterial event, coronary artery or peripheral artery event increased by nearly 10% for any increase in Hcy of 5 micromol/L. In conclusion, high Hcy may be involved in the pathogenesis of cardiovascular events in OLT patients. The usefulness of Hcy-lowering therapy remains to be verified.

Free radical-dependent dysfunction of small-for-size rat liver grafts: prevention by plant polyphenols

BACKGROUND & AIMS

The mechanisms by which small-for-size liver grafts decrease survival remain unclear. This study investigated the role of free radicals in injury to small-for-size grafts.

METHODS

Rat liver explants were reduced in size ex vivo and transplanted into recipients of the same or greater body weight, resulting in a graft weight and standard liver weight of approximately 50% and 25%, respectively. A polyphenol extract from Camellia sinenesis (20 microg/mL) or an equivalent concentration of epicatechin was added to the storage solution and the lactated Ringer poststorage rinse solution.

RESULTS

Serum alanine aminotransferase release increased from approximately 60 U/L before implantation to 750, 1410, and 2520 U/L after full-size, half-size, and quarter-size transplantation, respectively. Total bilirubin increased slightly after transplantation of full-size and half-size grafts but increased 104-fold in quarter-size grafts. In quarter-size grafts, histological changes included necrosis, leukocyte infiltration, and eosinophilic inclusion body formation. Polyphenol treatment ameliorated these effects by > or =67%. Survival was 30% after transplantation of small-for-size grafts. After polyphenol treatment, survival increased to 70%. Free radicals in bile assessed by spin trapping and 4-hydroxynonenal adducts measured by immunohistochemistry were also greater in reduced-size grafts, an effect ameliorated by polyphenols. Epicatechin, a major polyphenol from Camellia sinenesis, also improved graft function and decreased enzyme release, histopathologic changes, and free radical formation.

CONCLUSIONS

Increased formation of free radicals occurs after transplantation of reduced-size livers, which contributes to graft dysfunction and failure. Plant polyphenols decrease liver graft injury and increase survival of small-for-size liver grafts, most likely by scavenging free radicals.

Lobular damage caused by cellular and humoral immunity in liver allograft rejection

BACKGROUND

Diagnosis of acute liver allograft rejection (ALAR) is usually performed by the estimation of changes in portal areas. In this study, changes in the hepatic lobules were investigated retrospectively by immunohistochemistry, and compared with changes in the portal areas. Humoral immunity in ALAR was also studied by C4d-staining.

MATERIALS AND METHODS

In total, 35 biopsy specimens from 20 patients who had undergone living-related liver transplantation were included. Specimens had been graded as mild, moderate-to-severe acute rejection based on the Banff Schema. Changes in hepatic lobules were investigated by hematoxylin-eosin (H & E) staining, an immunohistochemical study using anti-CD3 (T cells), anti-GMP-17 (cytotoxic cells), anti-CD68 (macrophages) and C4d, and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) method.

RESULTS

Changes in hepatic lobules consisted of the infiltration of mononuclear cells, swelling and necrosis of hepatocytes, and hemorrhages. The degree of these changes increased with the severity of ALAR. Immunohistochemical analysis revealed that infiltrating cells included CD3+ T cells, GMP-17+ cytotoxic cells and CD68+ macrophages. The number of infiltrating cells increased with the severity of the ALAR. The TUNEL assay demonstrated apoptotic cells in ALAR and the number of apoptotic cells increased with the severity of the ALAR. In moderate-to-severe rejection, C4d depositions were observed in the hepatic sinusoids as well as the portal veins and hepatic arteries.

CONCLUSIONS

Changes in the hepatic lobules were observed in ALAR and the severity increased with the severity of ALAR. Apoptosis was involved in the mechanism of cell death and humoral immunity plays a role in the mechanism of ALAR.

Repopulation of athymic mouse liver by cryopreserved early human fetal hepatoblasts

Transplantation of hepatocytes is a promising alternative to liver transplantation for the treatment of severe liver diseases. However, this approach is hampered by the shortage of donor organs and intrinsic limitations of adult hepatocytes. To investigate whether most of the hurdles faced with adult hepatocytes could be surmounted by the use of human fetal hepatoblasts, we have developed a method to isolate, transduce, and cryopreserve hepatoblasts from human livers at an early stage of development (11-13 weeks of gestation). Cells were characterized in vitro for expression of specific markers, and in vivo for their proliferation and differentiation potential after transplantation into athymic mice. Most of the cells (80-90%) harbored a bipotent phenotype, expressing cytokeratins 8/18, albumin, and CK19. They proliferated spontaneously in culture and were efficiently transduced by a beta-galactosidase-expressing retrovirus (90%). After transplantation, cryopreserved cells engrafted into the liver of athymic mice and proliferated, resulting in up to 10% repopulation. Engrafted cells expressed markers of differentiated adult hepatocytes including albumin, alpha1-antitrypsin, cytochrome P450 3A4, and alpha-glutathione-S-transferase. When retrovirally transduced before transplantation they expressed the transgene in vivo. In summary, early human fetal hepatoblasts engraft, proliferate, and mature in athymic mouse liver, without conditioning the donor.

Laparoscopic left hemicolectomy in a patient with cirrhosis scheduled for liver transplantation

Hepatic cirrhosis is a negative prognostic factor for major abdominal surgery, with a greater risk of bleeding, infection, and ascites. The case of a 54-year-man with adenocarcinoma of the sigma affected by hepatitis B virus and hepatitis C virus hepatopathy as well as micro- and macrconodular cirrhosis (Child's B7 stage) waiting for liver transplantation is reported. After a consultation with the liver transplantation our hospital, and considering the the patient's age laparoscopy was determined to be the procedure of choice because it would give him the possibility of a transplantation in the future. A typical left hemicolectomy with left flexure mobilization and mechanic colorectal T-T-anastomosis was therefore performed. All surgical maneuvers in the right hypochondrium were avoided. Mobilization was performed using an ultrasonic scalpel to reduce the risk of bleeding, and the anatomic stump was pulled out by means of a midline minilaparotomy, sparing the anastomotic circles of the abdominal wall. Follow-up evaluation was uneventful. At an 8-month follow-up visit, the patient was in good general condition. In this case, laparoscopic surgery allowed an oncologically suitable colonic resection without complication and poor surgical stress. Moreover, open surgery would have reduced the possibility of a transplantation in the future.

Cardiac morbidity and mortality related to orthotopic liver transplantation

This article briefly discusses the cardiac status of liver transplant recipients and their preoperative cardiac evaluation. It describes in detail perioperative and early and late postoperative complications as well as the cardiac problems associated with immunosuppression. The preoperative cardiovascular status of patients is important in determining how they cope with the stresses imposed by liver transplantation. Minor early cardiac events are common and may influence longer term cardiac morbidity. Immunosuppressive therapy may have short term effects but is likely to adversely affect long term cardiac risk.

Role of free radicals in failure of fatty liver grafts caused by ethanol

Alcohol is associated with accidental deaths and suicides leading to organ donation, and hepatic steatosis is an important risk factor for initial poor function and failure of human liver grafts. Mechanisms of fatty graft failure are not fully understood, but increased oxidative stress may be a major factor. To characterize the role of free radical stress and the efficacy of antioxidant treatments in fatty liver graft injury, donors for orthotopic rat liver transplantation were treated chronically (3 or more weeks) and acutely (single dose) with ethanol. After transplantation, necrosis and alanine aminotransferase release were threefold to fourfold higher in recipients of fatty grafts from donors treated with ethanol either acutely or chronically compared with findings for recipients of grafts from untreated donors. Moreover, graft survival decreased from nearly 100% to less than 20%. Free radical adducts, as measured by electron spin resonance spectroscopy, were detected in the blood and bile of rats receiving fatty grafts caused by ethanol. Markers of lipid peroxidation also increased after transplantation. Destruction of Kupffer cells with gadolinium chloride decreased free radical production and improved graft survival. Leukocyte adhesion increased beginning early after implantation, and adherent white blood cells obtained from transplanted fatty livers produced the same free radical species as were detected in blood. Therefore, Kupffer cells and adherent white blood cells are important sources of free radicals. Free radicals not only damage fatty grafts directly but also lead to enhanced inflammation and disturbed microcirculation. Delivery of superoxide dismutase-1 and superoxide dismutase-2 genes, free radical-scavenging polyphenols, and antioxidant-containing Carolina Rinse solution reduced injury and improved survival of fatty grafts caused by ethanol. Taken together, these findings indicate that free radicals increase in fatty grafts after transplantation and play an important role in injury of fatty grafts obtained from ethanol-exposed donors. Treatment of fatty donor livers with antioxidants and free radical scavengers may thus be an effective clinical therapy to prevent failure of fatty grafts.

Polyphenols from Camellia sinenesis prevent primary graft failure after transplantation of ethanol-induced fatty livers from rats

Fatty liver caused by ethanol decreases survival after liver transplantation in rats. This study investigated if antioxidant polyphenols from Camellia sinenesis (green tea) prevent failure of fatty grafts from ethanol-treated rats. Donor rats were given ethanol intragastrically (6 g/kg). After 20 h, livers were explanted and stored in University of Wisconsin solution for 24 h. Prior to implantation, the explanted grafts were rinsed with lactated Ringer's solution containing 0 to 60 microg/ml polyphenols. Alanine aminotransferase (ALT) release after liver transplantation was 4.5-fold higher in recipients receiving ethanol-induced fatty grafts than in those receiving normal grafts. Liver grafts from ethanol-treated donors also developed severe focal necrosis. Graft survival was 11% in the ethanol group versus 88% for normal grafts. Polyphenol treatment at 60 microg/ml blunted ALT release by 66%, decreased necrotic areas by 84%, and increased survival to 75%. Ethanol increased alpha-(4-pyridyl-1-oxide)-N-tert.-butylnitrone free radical adducts in bile by 2.5-fold, as measured by electron spin resonance spectroscopy, and caused accumulation of 4-hydroxynonenal in liver sections, effects blunted by polyphenols. Epicatechin gallate, a major polyphenol from C. sinenesis, also decreased enzyme release, minimized pathological changes, and decreased free radical adduct formation. In conclusion, polyphenols scavenged free radicals in ethanol-induced fatty livers and decreased injury after liver transplantation.

Association between ABCB1 (multidrug resistance transporter) genotype and post-liver transplantation renal dysfunction in patients receiving calcineurin inhibitors

OBJECTIVE

Renal dysfunction is a common and costly adverse outcome of long-term treatment with calcineurin inhibitors (CNIs). We conducted a retrospective, case-control study to test whether the risk of renal dysfunction in liver transplantation patients receiving CNIs is associated with the 2677G>T transversion in exon-21 of the gene (ABCB1) encoding P-glycoprotein. A total of 120 non-Hispanic white patients were evaluated.

RESULTS

The overall incidence of renal dysfunction by year 3 post-transplantation was 40%. The frequency of renal dysfunction was reduced among patients with an ABCB1 2677TT genotype, as compared to those with a 2677GG genotype. Subjects with a heterozygote genotype behaved phenotypically like the 2677GG group. Comparing those subjects with a 2677TT genotype to the combined group of subjects with a 2677GG, TG, AT, or AG genotype resulted in an odds ratio of 0.26 (0.09-0.77). When subjects were stratified by gender, the frequency of renal dysfunction was reduced among men with an ABCB1 2677TT genotype, relative to men with different genotypes. A similar odds ratio was obtained for women, but it did not achieve significance. When 18 subjects with an elevated SCr concentration just prior to surgery were excluded from the year 3 analysis, the association between the 2677TT genotype and chronic renal dysfunction in the remaining cohort was strengthened comparing genotype groups.

CONCLUSIONS

Based on these results, we conclude that homozygosity for the ABCB1 2677T (S893) allele is associated with reduced risk of chronic renal dysfunction among liver transplantation patients receiving an immunosuppressive regimen containing CNIs.

Usefulness of preoperative stress perfusion imaging in predicting prognosis after liver transplantation

The role of preoperative stress single-photon emission computed tomographic (SPECT) imaging in patients with end-stage liver disease who underwent liver transplantation is not well established. We reviewed medical records of patients who had liver transplantation at our institution between January 1998 and November 2001. During this time, 339 patients (213 men, aged 51 +/- 11 years) underwent liver transplantation. Of these, 87 patients had preoperative stress SPECT imaging. Diabetes mellitus (30% vs 11%), hypertension (26% vs 12%), and coronary artery disease (15% vs 7%) were more prevalent in those with than without SPECT (p <0.01 each). The stress SPECT perfusion images were normal in 78 patients (91%) and the left ventricular ejection fraction was 72 +/- 10%. SPECT images revealed ascites in 66% and splenomegaly in 83% of patients. There were 35 total deaths (10%) and 5 nonfatal myocardial infarctions over a mean follow-up of 21 +/- 13 months. Most deaths (32 of 35) were noncardiac and sepsis was the most common cause of death. A normal SPECT study had a 99% negative predictive value for perioperative cardiac events. Kaplan-Meier survival curves showed an 87% 2-year cumulative survival rate in the total group. Thus, in patients undergoing liver transplantation, 2-year survival depends on early noncardiac events. A normal stress SPECT study identified patients at a very low risk for early and late cardiac events despite a higher risk profile. SPECT images also revealed unique findings, such as ascites and splenomegaly, which could produce image artifacts and may interfere with accurate image interpretation.

Clinical implications of hepatic preservation injury after adult liver transplantation

Several advances in organ preservation have allowed for improved results after liver transplantation; however, little information is available regarding the clinical impact of preservation injury on the postoperative course. The medical records of 889 liver transplants were retrospectively reviewed. Preservation injury was classified according to postoperative aspartate aminotransferase values as minor (<1000 U/L), moderate (1000-5000 U/L), or severe (>5000 U/L). The following criteria were analyzed and compared according to the extent of preservation injury: patient and graft survival, retransplantation rate, duration of hospitalization and postoperative ventilation, as well as incidence of rejection, infection, and hemodialysis. The majority of patients received a liver with minor preservation injury (75.9%), whereas 22.7% and 1.3% of grafts showed moderate or severe injury. Graft survival was significantly lower in patients with severe preservation injury, when compared to minor or moderate injury. The relative risk for initial nonfunction was 39.36-fold increased (95% confidence interval (ci): 10.3-150.2), as it was increased for duration of postoperative ventilation (6.92-fold; 95%ci: 2.1-22.3) and hemodialysis (6.13-fold; 95%ci: 1.9-19.3). Since the incidence of retransplantation was significantly increased (50%), patient survival remained comparable between all groups. Severe preservation injury had a tremendous impact on the postoperative clinical course, requiring the maximum medical effort to achieve adequate patient survival.

Hepatobiliary scintigraphy in liver transplant patients: the "blind end sign" and its differentiation from bile leak

PURPOSE

Hepatobiliary scintigraphy is commonly performed on liver transplant patients to exclude biliary complications such as obstruction or leak. Biliary reconstruction in these patients is performed using either a direct duct-to-duct anastomosis (choledochocholedochostomy) or a biliary-enteric anastomosis (Roux-en-Y hepaticojejunostomy). The authors have observed a finding in scans performed on the latter group of patients that often simulates a bile leak. They postulate this finding to represent retention of activity in the blind end of the Roux limb (the "blind end sign"). The purpose of this study was to determine characteristics of this blind end activity, which may help differentiate it from true bile leaks.

METHODS

Two nuclear medicine physicians reviewed 36 Tc-99m mebrofenin hepatobiliary scans (31 patients). Biliary reconstruction was performed in 25 patients with a Roux-en-Y hepaticojejunostomy, and in 6 patients with a choledochocholedochostomy. Each scan was evaluated regarding whether there was focal, persistent retention of activity in the anastomotic region, and, if so, various features of the activity were noted. Activity was concluded to represent a true bile leak based on subsequent surgical confirmation, and if there was no such confirmation, the activity was concluded to represent blind end retention in patients with Roux-en-Y hepaticojejunostomies.

RESULTS

There were 8 total examples of blind end activity and 3 examples of bile leak activity. Useful discriminators between the 2 types of activity included the following: fluctuation in size and/or intensity with time (8 of 8 blind end cases vs. 0 of 3 bile leak cases); size comparable with bowel (8 of 8 vs. 1 of 3); tubular (4 of 8 vs. 0 of 3), round (4 of 8 vs. 1 of 3), or irregular (0 of 8 vs. 2 of 3) shape; and movement into bowel (3 of 8 vs. 0 of 3). Delayed imaging was performed in 3 cases at 1.5 hours, but was only conclusive in 1 case in which diffuse extravasation was seen consistent with bile leak.

CONCLUSION

Retention of activity in the blind end of the Roux limb in patients with Roux-en-Y hepaticojejunostomies may simulate bile leak, but certain typical features, as well as delayed imaging, may aid in distinguishing the two.

Hepatic artery thrombosis after adult liver transplantation

The incidence, clinical presentation, therapeutic options, and outcome of hepatic artery thrombosis (HAT) were analyzed in a series of 1,192 consecutive adult orthotopic liver transplantations (OLTs). HAT after OLT was observed in 30 cases, resulting in an incidence of 2.5%. The incidence of HAT increased 5.76-fold when the donor hepatic artery was reconstructed with an interposition graft to the supraceliac aorta (P <.05). Early HAT (within the first 30 days after OLT) occurred in 14 of these patients (46.7%), whereas in 16 patients (53.3%), HAT occurred beyond 30 days post-OLT. Clinical presentation of HAT ranged from an increase in serum transaminase levels with or without cholestasis to liver abscess and biliary complications, including cholangitis, bile duct stenosis or necrosis, to liver dysfunction and failure. Impairment of graft function was observed in patients with early HAT, whereas biliary tract destruction was seen more often in patients with late HAT. In only 1 patient was HAT clinically asymptomatic. Therapy consisted of recombinant plasminogen lysis with hepaticojejunostomy, liver abscess drainage, endoscopy or surveillance, and surgical thrombectomy. In 14 of 30 patients (46.7%), the occurrence of HAT required re-OLT. Nine patients with HAT died during follow-up; however, only 4 of these deaths were related to HAT, resulting in a mortality rate of 13.3%. Our results indicate that HAT is a rare but serious complication after OLT, requiring re-OLT in almost 50% of patients. In particular, conservative treatment modalities may significantly prolong graft survival, thus postponing re-OLT.

Kidney transplantation after liver transplantation from the same donor: four cases of successful steroid withdrawal

BACKGROUND

Administration of corticosteroids to kidney recipients has hampered the complete clinical success of kidney transplantation. Because most organ transplantation in Japan is living-related, we had the experience of performing kidney transplantation (KT) after liver transplantation (LT) from the same donor in four patients and successfully withdrew corticosteroid administration.

METHODS

Three pediatric and one adult patient received kidney allografts from 3 to 10 months after LT from the same donor. The immunosuppressive regimen consisted of a corticosteroid and tacrolimus. The steroid was withdrawn after KT in all four patients. After complete withdrawal of the steroid, DNA was extracted from two recipients and examined by polymerase chain reaction to detect microchimerism. A mixed lymphocyte reaction (MLR) and cell-mediated lymphocytotoxicity assay (CML) were performed to test for donor-specific hyporesponsiveness.

RESULTS

Steroid withdrawal was successfully accomplished after KT in every patient. No steroid-withdrawal-associated complications were observed. In the three pediatric patients, remarkable catch-up growth was observed after steroid withdrawal. In the two patients tested, donor DNA was not detected by polymerase chain reaction, suggesting the absence of microchimerism. MLR and CML showed that recipient lymphocytes reacted against donor lymphocytes at the same level as against the third-party lymphocytes.

CONCLUSION

Steroid withdrawal was successfully achieved in four kidney recipients who had received a liver allograft from the same donor. The MLR and CML findings indicated the absence of donor-specific hyporesponsiveness in vitro. Although the precise mechanism is not yet clear, KT after LT from the same donor should be considered as a method that allows steroids to be withdrawn from the immunosuppressive regimen of KT.

Cost-effectiveness of cadaveric and living-donor liver transplantation

BACKGROUND

Cadaveric liver transplantation (5-year survival >80%) represents the standard of care for end-stage liver disease (ESLD). Because the demand for cadaveric organs exceeds their availability, living-donor liver transplantation has gained increasing acceptance. Our aim was to assess the marginal cost-effectiveness of cadaveric and living-donor orthotopic liver transplantation (OLT) in adults with ESLD.

METHODS

Using a Markov model, outcomes and costs of ESLD treated (1) conservatively, (2) with cadaveric OLT alone, and (3) with cadaveric OLT or living-donor OLT were computed. The model was validated with published data. The case-based scenario consisted of data on all 15 ESLD patients currently on our waiting list (3 women, 12 men; median age, 48 years [range, 33-59 years]) and on the outcome of all OLT performed for ESLD at our institution since 1995 (n=51; actuarial 5-year survival 93%). Living-donor OLT was allowed in 15% during the first year of listing; fulminant hepatic failure and hepatocellular carcinoma were excluded.

RESULTS

Cadaveric OLT gained on average 6.2 quality-adjusted life-years (QALYs) per patient compared with conservative treatment, living-donor OLT, an additional 1.3 QALYs compared with cadaveric OLT alone. Marginal cost-effectiveness of a program with cadaveric OLT alone and a program with cadaveric and living-donor OLT combined were similar (E 22,451 and E 23,530 per QALY gained). Results were sensitive to recipient age and postoperative survival rate.

CONCLUSIONS

Offering living-donor OLT in addition to cadaveric OLT improves survival at costs comparable to accepted therapies in medicine. Cadaveric OLT and living-donor OLT are cost-effective.

Prospects for the temporary treatment of acute liver failure

At present, the most successful treatment of acute liver failure is orthotopic liver transplantation, with survival rates ranging from 70% to 85%. However, mortality rates for liver failure remain high because of the shortage of available donor organs. Therefore, there has been renewed interest in temporary treatment methods for patients with acute liver failure to either allow liver regeneration or await liver transplantation. It is thought that the function of the liver can only be replaced with the biological substrate, e.g. liver cells or a whole liver specimen, which requires the availability of liver tissue from xenogeneic or human sources. In this review, existing temporary liver support techniques are summarized and the potential hazards are described. These include the immunological implications of these techniques, e.g. the host versus graft reaction, which may influence the effectivity of the support system, and in the long run may sensitize the patient to subsequent allogeneic transplantation. The graft versus host reaction is also considered. At present, one of the major concerns is the threat of pig-to-human transmission of activated endogenous retrovirus present in the pig genome. An overview is given of literature concerning the transmission of retrovirus particles in vitro and in vivo. Finally, new solutions for the development of ex vivo systems for temporary treatment of patients with acute liver failure are discussed. These include the use of new immortalized human cell lines and human fetal hepatocytes, and the possibility of isolating, expanding and genetically manipulating stem cells in order to have stable differentiated and committed cells.

Disease recurrence after liver transplantation in Western Australia

BACKGROUND AND AIM

Orthotopic liver transplantation (OLT) is now the accepted therapy for end-stage chronic liver disease. Long-term survival is now expected in the majority of patients and, consequently, disease recurrence has emerged as a major concern. Our aim was to document the rate of disease recurrence after liver transplantation for conditions other than hepatitis C, in patients followed up by the Western Australian Liver Transplant Service (WALTS).

METHODS

The case notes of all post-OLT patients followed up by WALTS were reviewed. Patients were excluded if survival was less than 3 months post-OLT; OLT was performed for hepatitis C alone or follow up was unavailable. Detection and definition of disease recurrence depended on pretransplant diagnosis, and were based on patient interview, biochemical, immunological and serological tests. Radiological and histological confirmation were obtained where clinically indicated.

RESULTS

Eighty-seven patients were identified (89 OLTs performed). The overall rate of recurrence was 10%. Recurrence rates by disease were: primary sclerosing cholangitis (17%), primary biliary cirrhosis (12%), autoimmune hepatitis (17%), hepatitis B (40%) and alcoholic liver disease (4%). Alcohol use relapse after transplantation occurred in 25%. The overall survival post-OLT was 87%, with a mean follow up of 53 months. Survival in patients with recurrent disease was 89%.

CONCLUSIONS

Disease recurrence after OLT does occur, but overall, it is relatively uncommon. Recurrence rates vary significantly and depend, in part, on indication for OLT. With medium-term follow up, recurrent disease does not have an effect on mortality.