An evaluation of long-term outcomes after liver transplantation for cryptogenic cirrhosis

Long-term liver allograft fibrosis: A review with emphasis on idiopathic post-transplant hepatitis and chronic antibody mediated rejection

Liver transplantation (LT) is a life-saving surgical procedure and the current standard of care for most patients with end stage liver disease. With improvements in organ preservation techniques, perioperative care, and immunosuppression, there is better patient and graft survival following LT, and assessment of the liver allograft in long-term survivors is becoming increasingly important. Recurrent or de novo viral or autoimmune injury remains the most common causes of chronic hepatitis and fibrosis following liver transplantation in adults. However, no obvious cause can be identified in many adults with controlled recurrent disease and the majority of pediatric LT recipients, as they have been transplanted for non-recurrent liver diseases. Serial surveillance liver biopsies post LT have been evaluated in several adult and pediatric centers to identify long-term pathological changes. Pathological findings are frequently present in liver biopsies obtained after a year post LT. The significance of these findings is uncertain as many of these are seen in protocol liver biopsies from patients with clinically good allograft function and normal liver chemistry parameters. This narrative review summaries the factors predisposing to long-term liver allograft fibrosis, highlighting the putative role of idiopathic post-LT hepatitis and chronic antibody mediated rejection in its pathogenesis.

Histopathological Examination of Explanted Liver After Transplantation in Patients With Cryptogenic Cirrhosis

OBJECTIVES

Cryptogenic cirrhosis is a common indication for liver transplantation. Diagnosis is made after exclusion of other causes of cirrhosis. In this study, the aim was to evaluate patients with cryptogenic cirrhosis after histopathological examination of explanted liver.

MATERIALS AND METHODS

A retrospective histopathological chart review of 117 patients with cryptogenic cirrhosis who had liver transplantation between November 2009 and June 2014 was performed. Age, sex, operative features, survival rates, and preoperative and postoperative diagnosis were evaluated.

RESULTS

During the study period, 123 liver transplantations were performed for these 117 patients. Deceased donor liver transplantations were performed in 23 (18.7%) of the cases. Retransplantations were performed in 5 patients. Median age was 48 years, and female-to-male ratio was 41:76. Hepatosteatosis were observed in 29 patients. Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis were observed in 20 (12%) and 9 (7.7%) of these patients, respectively. Autoimmune hepatitis was observed in 2 patients. The definitive cause of cirrhosis was unclear in 68 (58%) of the patients. Incidental malignant and premalignant lesions were observed in 15 patients.

CONCLUSIONS

Histopathological examination of the explanted liver after liver transplantation in those patients with cryptogenic cirrhosis may significantly help to diagnose the cause of cirrhosis, such as nonalcoholic steatohepatitis or autoimmune hepatitis, with using the scoring system developed by the International Autoimmune Hepatitis Workgroup. In addition, incidental malignant or premalignant lesions may be observed.

Nonalcoholic fatty liver disease following liver transplantation

Post-transplant, nonalcoholic hepatic steatosis and steatohepatitis are increasingly recognized as a complication of liver transplantation, and the progression of the latter through fibrosis to cirrhosis has been clearly shown. Non-alcoholic steatohepatitis (NASH) is independently associated with an increased risk of death from cardiovascular and liver diseases. While optimal therapy is not yet available in the post-liver transplant setting, knowledge gained in the therapy of NASH in the non-transplant setting can be used to design therapeutic interventions. In addition, early recognition with protocol liver biopsies and an effective preventive strategy by modifying known risk factors implicated in the recurrence of NASH would be the most effective way to curtail the progression of NASH before an effective treatment can be found. Additional rigorous research aimed at elucidating the pathogenesis, natural history, and selection of immunosuppressants for NASH is clearly warranted.

Importance of liver biopsy findings in immunosuppression management: biopsy monitoring and working criteria for patients with operational tolerance

Obstacles to morbidity-free long-term survival after liver transplantation (LT) include complications of immunosuppression (IS), recurrence of the original disease and malignancies, and unexplained chronic hepatitis and graft fibrosis. Many programs attempt to minimize chronic exposure to IS by reducing dosages and stopping steroids. A few programs have successfully weaned a highly select group of recipients from all IS without apparent adverse consequences, but long-term follow-up is limited. Patients subjected to adjustments in IS are usually followed by serial liver chemistry tests, which are relatively insensitive methods for detecting allograft damage. Protocol biopsy has largely been abandoned for hepatitis C virus-negative recipients, at least in part because of the inability to integrate routine histopathological findings into a rational clinical management algorithm. Recognizing a need to more precisely categorize and determine the clinical significance of findings in long-term biopsy samples, the Banff Working Group on Liver Allograft Pathology has reviewed the literature, pooled the experience of its members, and proposed working definitions for biopsy changes that (1) are conducive to lowering IS and are compatible with operational tolerance (OT) and (2) raise concern for closer follow-up and perhaps increased IS during or after IS weaning. The establishment of guidelines should help us to standardize analyses of the effects of various treatments and/or weaning protocols and more rigorously categorize patients who are assumed to show OT. Long-term follow-up using standardized criteria will help us to determine the consequences of lowering IS and to define and determine the incidence and robustness of OT in liver allografts.

[Histological lesions in the graft in patients with long-term survival after transplantation. Are protocol biopsies necessary?]

The main lesions found in long-term liver grafts are recurrence of underlying liver disease and the development of de novo diseases or heterogeneous lesions of unknown etiology. In a not insignificant percentage of patients, the results of laboratory tests are normal and these lesions are only detected by liver biopsy. Diagnosis of these lesions is essential since they can affect patient and graft prognosis and may require changes in immunosuppressive therapy or the introduction of new drugs to treat specific diseases. Moreover, some patients with normally functioning liver grafts could benefit from minimization of immunosuppressive therapy. Currently, the performance of protocol biopsies cannot be recommended. However, given the high prevalence of these lesions, grafts should be closely monitored. Transient elastrography could play a role in the selection of patients who might benefit from a liver biopsy.

Autoantibody-negative autoimmune hepatitis

Autoimmune hepatitis has a variable clinical phenotype, and the absence of conventional autoantibodies does not preclude its diagnosis or need for treatment. The goals of this review are to describe the frequency and nature of autoantibody-negative autoimmune hepatitis, indicate its outcome after corticosteroid treatment, and increase awareness of the diagnosis in patients with unexplained acute and chronic hepatitis. The frequency of presumed autoantibody-negative autoimmune hepatitis in patients with acute and acute severe presentations is ≤7%, and its frequency in patients with chronic presentations is 1-34%. Patients with acute presentations can have normal serum γ-globulin levels, centrilobular zone 3 necrosis, and low pre-treatment international diagnostic scores. Liver tissue examination is essential for the diagnosis, and hepatic steatosis can be a co-morbid feature. The comprehensive international scoring system can support but never override the clinical diagnosis pre-treatment, and non-standard serological markers should be sought if the clinical diagnosis is uncertain or the diagnostic score is low. A 3-month treatment trial with corticosteroids should be considered in all patients, regardless of the serological findings, and improvements have occurred in 67-87% of cases. Autoantibody-negative autoimmune hepatitis may be associated with an autoantibody outside the conventional battery; it may have a signature autoantibody that is still undiscovered, or its characteristic autoantibodies may have been suppressed or have a delayed expression. The pathogenic mechanisms are presumed to be identical to those of classical disease. Autoantibody-negative autoimmune hepatitis is an infrequent but treatable disease that must be considered in unexplained acute and chronic hepatitis.

Cryptogenic chronic hepatitis and its changing guise in adults

Cryptogenic chronic hepatitis is a disease that is unexplained by conventional clinical, laboratory and histological findings, and it can progress to cirrhosis, develop hepatocellular carcinoma, and require liver transplantation. The goals of this review are to describe the changing phenotype of cryptogenic chronic hepatitis in adults, develop a diagnostic algorithm appropriate to current practice, and suggest treatment options. The frequency of cryptogenic hepatitis is estimated at 5.4%. Cryptogenic cirrhosis is diagnosed in 5-30% of patients with cirrhosis, and it is present in 3-14% of adults awaiting liver transplantation. Nonalcoholic fatty liver disease has been implicated in 21-63% of patients, and autoimmune hepatitis is a likely diagnosis in 10-54% of individuals. Viral infections, hereditary liver diseases, celiac disease, and unsuspected alcohol or drug-induced liver injury are recognized infrequently in the current cryptogenic population. Manifestations of the metabolic syndrome heighten the suspicion of nonalcoholic fatty liver disease, and the absence of hepatic steatosis does not discount this possibility. The diagnostic scoring system of the International Autoimmune Hepatitis Group can support the diagnosis of autoimmune hepatitis in some patients. Certain genetic mutations may have disease-specificity, and they suggest that some patients may have an independent and uncharacterized disease. Corticosteroid therapy is effective in patients with autoimmune features, and life-style changes and specific therapies for manifestations of the metabolic syndrome are appropriate for all obese patients. The 1- and 5-year survivals after liver transplantation have ranged from 72-85% to 58-73%, respectively.

What is the long-term outcome of the liver allograft?

With improved long-term survival following liver transplantation (LT), issues relating to the assessment of the liver allograft in long-term survivors are becoming increasingly relevant. Histological abnormalities are commonly present in late post-transplant biopsies, including protocol biopsies from patients who appear to be well with good graft function. Recurrent disease is the commonest recognised cause of abnormal graft histology, but may be modified by the effects of immunosuppression or interactions with other graft complications, resulting in complex or atypical changes. Other abnormalities seen in late post-transplant biopsies include rejection (which often has different appearances to those seen in the post-transplant period), de novo disease, "idiopathic" post-transplant hepatitis (IPTH) and nodular regenerative hyperplasia. In many cases graft dysfunction has more than one cause and liver biopsy may help to identify the predominant cause of graft damage. Problems exist with the terminology used to describe less well understood patterns of graft injury, but there is emerging evidence to suggest that late rejection, de novo autoimmune hepatitis and IPTH may all be part of an overlapping spectrum of immune-mediated injury occurring in the late post-transplant liver allograft. Careful clinico-pathological correlation is very important and the wording of the biopsy report should take into account therapeutic implications, particularly whether changes in immunosuppression may be indicated. This article will provide an overview of the main histological changes occurring in long-term survivors post-LT, focusing on areas where the assessment of late post-transplant biopsies is most relevant clinically.

Liver transplantation of patients with cryptogenic cirrhosis: clinical characteristics and outcome

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD), autoimmune hepatitis (AIH) and unapparent alcohol abuse may be underlying causes of cryptogenic cirrhosis, but the frequencies of these underlying factors differ between studies. Also, previous studies have shown various outcomes after orthotopic liver transplantation (OLT) for cryptogenic cirrhosis. The aims of this study were (1) to evaluate the presence of NAFLD in patients with cryptogenic cirrhosis evaluated for OLT and (2) to compare the severity of liver disease and patient survival in OLT candidates with cryptogenic cirrhosis and those with cirrhosis of another known origin.

MATERIAL AND METHODS

Four-hundred and seventy adult patients with end-stage liver cirrhosis evaluated for OLT between 1990 and 2004 were included, of whom 39 had cryptogenic cirrhosis. Clinical, histological and laboratory data that had been prospectively collected were re-evaluated.

RESULTS

Seventeen (44%) of the cryptogenic patients had NAFLD in a previous liver biopsy and/or clinical features of the metabolic syndrome. Two patients had occult alcohol over-consumption and one patient had burnt-out AIH. Cryptogenic patients had significantly higher frequencies of diabetes, ascites, and hyponatraemia and weight loss. Patient survival was similar between cryptogenic patients and cirrhotics with a known aetiology.

CONCLUSIONS

Re-evaluation of patient data discovered probable underlying aetiologies in 51% of patients with cryptogenic cirrhosis evaluated for OLT, of which NAFLD was the most common (44%). Although cryptogenic patients had a more advanced liver disease when evaluated for OLT, patient survival was similar. Recent weight loss was significantly more common in cryptogenic patients, possibly being a sign of liver decompensation and signalling a need for OLT evaluation.

Cryptogenic cirrhosis: what are we missing?

Cryptogenic cirrhosis remains a common clinical condition although recent advances have allowed for a better understanding of underlying conditions and associations. The evolving terminology applied to this condition has resulted in some confusion and persistent variation among pathologists and clinicians. Typical patients are middle aged with only minor liver enzyme abnormalities. Presentations range from incidentally discovered cirrhosis to complications of advanced portal hypertension and hepatocellular cancer. Clinicopathologic analysis of these patients indicates that the leading causes include previously unrecognized nonalcoholic steatohepatitis, silent autoimmune hepatitis, non-B, non-C viral hepatitis, and occult past ethanol exposure. In this article, we review these associations as well as a proposed classification system for cryptogenic cirrhosis and other lesser known genetic and syndromic associations that warrant consideration when evaluating these individuals.

Outcomes of liver transplantation in patients with cirrhosis due to nonalcoholic steatohepatitis versus patients with cirrhosis due to alcoholic liver disease

Nonalcoholic steatohepatitis (NASH) is becoming a common cause of liver cirrhosis requiring liver transplantation (LT). Cardiovascular complications related to metabolic syndrome and NASH recurrence in the transplanted liver may affect the outcome of LT in these patients. We compared the outcomes of LT for NASH cirrhosis and alcoholic cirrhosis (ETOH) in a large transplant center. A retrospective chart review was performed for all patients who underwent LT for cryptogenic cirrhosis with the NASH phenotype (the NASH group) or ETOH (the ETOH group) at the University of Miami from January 1997 to January 2007. There was no significant difference in survival between the NASH and ETOH groups, despite a trend toward lower survival in the former (P = 0.1699). Sepsis was the leading cause of posttransplant death in both groups, and it was followed by cardiovascular causes in the NASH group (26% versus 7% in the ETOH group, P = 0.21) and malignancies in the ETOH group (29% versus 0% in the NASH group, P = 0.024). Recurrent steatohepatitis (33% versus 0%, P < 0.0001) and acute rejection (41% versus 23%, P < 0.023) were significantly more frequent in the NASH group than in the ETOH group. There was no difference in graft failure between the groups (24% in the NASH group versus 18% in the ETOH group, P = 0.3973). In conclusion, despite a numerical trend favoring the ETOH group, there were no statistically significant differences in posttransplant survival and cardiovascular mortality between the NASH and ETOH groups. Acute rejection and recurrent steatohepatitis were significantly more frequent in the NASH group but did not lead to higher rates of retransplantation.

Epidemiology and natural history of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in many parts of the world. This article describes the epidemiology and natural history of this disorder. It also describes current diagnostic and treatment methods and describes future implications NAFLD may have.

Late protocol liver biopsies in the liver allograft: a neglected investigation?

As outcomes from liver transplantation have improved, attention has focused on long-term outcomes: patient and graft survival is affected by many factors, including the consequences of both overimmunosuppression (eg, renal failure and cancer) and underimmunosuppression (eg, rejection). The use of protocol (rather than event-driven) biopsies of the liver allograft, except for those grafted for HCV infection, has been largely abandoned. The aim of this study was to determine if protocol biopsies can improve the management of liver allograft recipients. A retrospective analysis of liver allograft recipients who had undergone protocol liver biopsies between 2000 and 2006 was performed. One hundred seventy-eight patients with normal liver tests (alcoholic liver disease, 49; autoimmune hepatitis, 20; and primary biliary cirrhosis, 107) who had undergone 235 protocol biopsies were identified. No significant complication from the biopsy was recorded. Liver histology was reported as normal or nearly normal in only 57 (24%). Chronic hepatitis (not obviously related to disease recurrence) was present in 78 (33%). Interpreted in the light of the calculated creatinine clearance, the biopsy findings indicated that overall immunosuppression (IMS) should be maintained or increased with standard calcineurin inhibitor (CNI)-based IMS in 25% of cases, that overall IMS should be reduced in 15% of cases, and that overall IMS should be maintained or increased by the substitution of non-nephrotoxic agents for CNIs in 9% of cases. The histological findings led to a documented change in IMS in 76 (32%) (increased IMS, 11; decreased IMS, 58; and switch from CNI, 7). In conclusion, protocol liver biopsy provides important histological information about graft function that is not available from standard liver tests and safely allows modification of IMS to ensure that long-term side effects of drug therapy (eg, renal failure) are minimized while graft function is sustained. Liver Transpl 15:931-938, 2009. (c) 2009 AASLD.

Metabolic syndrome in liver transplantation: relation to etiology and immunosuppression

Excessive weight gain, hypertension, hyperlipidemia, and diabetes are frequently observed in patients having undergone liver transplantation (LTx). These alterations are probably multifactorial in origin, and cluster to generate a metabolic syndrome (MS), increasing the risk of cardiovascular events. We assessed the prevalence of MS (National Cholesterol Education Program-Adult Treatment Panel III criteria) in 296 LTx patients in the course of regular follow-up, at least 6 months after transplantation (median, 38 months). Several pre-LTx and post-LTx data were collected to identify the factors associated with the presence of MS. In a subset of 99 patients, insulin resistance was measured by the homeostasis model assessment. High blood pressure was present in 53% of cases, hyperlipidemia in 51%, high glucose in 37%, and enlarged waist circumference in 32%. Overall, MS (defined as 3 or more of the above features) was present in 44.5% of cases. Insulin resistance (homeostasis model assessment > 2.7) was observed in 41% of cases. Hypertension and hyperlipidemia were more frequent in subjects on cyclosporine than in tacrolimus-treated cases, whereas the type of immunosuppressive drug had no effect on the prevalence of diabetes, enlarged waist, and MS. In a logistic regression analysis, only pre-LTx body mass index (odds ratio, 1.20), body mass index increase (odds ratio, 1.18), and pre-LTx diabetes (odds ratio, 2.36) predicted MS; age, gender, etiology of liver disease, time from LTx, type of immunosuppressive drug, and previous hepatocellular carcinoma were removed from the model. Disorders related to MS are frequent in LTx patients, and are related to both pre-LTx conditions and to weight gain. Weight control is mandatory in LTx patients to prevent risk factors of premature atherosclerosis.

The clinical significance of early histological rejection with or without biochemical abnormality in adult living donor liver transplantation for hepatitis B virus related end stage liver disease

There is no agreement regarding the treatment of early allograft rejection (EAR) in adult living donor liver transplantation (LDLT). A protocol biopsy was performed in 62 adult LDLT recipients. Twenty-one patients (33.9%) had histological evidence of EAR. Of these, 14 patients had biochemical abnormalities and seven patients had no associated biochemical abnormalities. None of the seven patients with subclinical EAR (11.3% of the entire study population) were treated, and no subsequent rejection was observed. Gender mismatch (female-to-male) was the single independent risk factor for histological EAR [odds ratio (OR) = 13.458; 95% confidence interval (CI), 1.836-98.649] and the cumulative probability for a subsequent rejection was higher in patients with EAR (OR = 11.085; 95% CI, 1.221-100.654). However, the actuarial 1 year patient and graft survival rate in patients with EAR (81.0% and 85.5%) were similar to those without EAR (92.7% and 97.25%; P = 0.127 and 0.302, respectively). The presence of an initial biochemical abnormality was an independent risk factor for both a decreased patient survival (OR = 5.827; 95% CI, 1.095-31.017; P = 0.039) and graft loss (OR = 20.646; 95% CI, 2.044-208.524; P = 0.010). Subsequent rejection developed more frequently in patients with EAR. However, the survival is not determined by the presence of EAR but by the presence of a biochemical abnormality.

Liver biopsy interpretation for causes of late liver allograft dysfunction

Evaluation of needle biopsies and extensive clinicopathological correlation play an important role in the determination of liver allograft dysfunction occurring more than 1 year after transplantation. Interpretation of these biopsies can be quite difficult because of the high incidence of recurrent diseases that show histopathological, clinical, and serological features that overlap with each other and with rejection. Also, more than one insult can contribute to allograft injury. In an attempt to enable centers to compare and pool results, improve therapy, and better understand pathophysiological disease mechanisms, the Banff Working Group on Liver Allograft Pathology herein proposes a set of consensus criteria for the most common and problematic causes of late liver allograft dysfunction, including late-onset acute and chronic rejection, recurrent and new-onset viral and autoimmune hepatitis, biliary strictures, and recurrent primary biliary cirrhosis and primary sclerosing cholangitis. A discussion of differential diagnosis is also presented.

Progressive histological damage in liver allografts following pediatric liver transplantation

The long-term histological outcome after pediatric liver transplantation (OLT) is not yet fully understood. De novo autoimmune hepatitis, consisting of histological chronic hepatitis associated with autoantibody formation and allograft dysfunction, is increasingly recognized as an important complication of liver transplantation, particularly in the pediatric population. In this study, 158 asymptomatic children with 5-year graft survival underwent protocol liver biopsies (113, 135, and 64 at 1, 5, and 10 years after OLT, respectively). Histological changes we re correlated with dinical,biochemical, and serological findings. All patients received cydosporine A as primary immunosuppression with withdrawal of corticosteroids at 3 months post OLT. Normal or near-normal histology was reported in 77 of 113 (68%), 61 of 135 (45%), and 20 of 64 (31%) at 1, 5, and 10 years, respectively. The commonest histological abnormality was chronic hepatitis (CH), the incidence of which increased with time [25/113 (22%), 58/135 (43%), and 41/64 (64%) at 1, 5, and 10 years, respectively) (P < .0001)]. The incidence of fibrosis associatedwith CH increasedwith time [13/25 (52%), 47/58 (81%), and 37/41 (91%) at 1, 5, and 10 years, respectively) (P < .0001)]. The severity of fibrosis associated with CH also increased with time, such that by 10 years 15% had progressed to cirrhosis. Aspartate aminotransfemse (AST) levels were slightly elevated in children with CH (median levels 52 IU/L, 63 IU/L, and 48 IU/L at 1, 5, and 10 years, respectively), but this did not reach statistical significance compared with those with normal histology. On multivariate analysis, the only factor predictive of chronic hepatitis was autoantibody positivity (present in 13% and 10% of children with normal biopsies at 5 and 10 years, respectively, and 72% and 80% of those with CH at 5 and 10 years, respectively) (P < .0001). Four children with CH and autoantibodies, who also had raised immunoglobulin G (IgG) levels and AST greater than 1.5 x normal fulfilled the diagnostic criteria for de novo autoimmune hepatitis (AIH). Another two were found to be hepatitis C positive. No definite cause for CH could be identified in the other cases. In condusion, chronic hepatitis is a common finding in children after liver transplantation and is associated with a high risk of developing progressive fibrosis, leading to cirrhosis. Standard liver biochemical tests cannot be relied on either in the diagnosis or in the monitoring of progress of chronic allograft hepatitis. In contrast, the presence ofautoantibodies is strongly associated with the presence of CH. The cause of chronic hepatitis in transplanted allografts is uncertain but may be immune mediated, representing a hepatitic form of chronic rejection.

Cryptogenic cirrhosis and NAFLD: are they related?

Cryptogenic cirrhosis (CC), literally meaning cirrhosis of obscure or unknown origin, is a diagnosis of exclusion. The circumstantial evidence indicates that nonalcoholic fatty liver disease (NAFLD) is perhaps one of the important causes of CC. There is also evidence, especially from the European literature, that some patients with CC may have undiagnosed or burnt-out autoimmune hepatitis (AIH). Other rare causes may include "unknown" viral (non-A, non-B, non-C) hepatitis, and occult alcoholism. In this review, we examine the role of NAFLD and other causes in the pathogenesis of CC, and the impact of obesity on patients with chronic liver disease.

Pathomorphological Features of Acute Rejection in Patients After Orthotopic Liver Transplantation: Own Experience

INTRODUCTION

Acute hepatic allograft rejection remains an important problem following liver transplantation. Liver biopsy specimens show a combination of characteristic changes, first observed by Snover as a diagnostic triad: portal inflammation, bile duct damage, and central or portal vein endothelial inflammation (endothelitis or endothelialitis). The aim of this study was to describe our histopathological assessment of liver transplants.

MATERIALS AND METHODS

In the period between September 2000 and June 2004, we evaluated 150 liver biopsy specimens from 105 liver recipients.

RESULTS

Acute rejection was diagnosed in 26.6% of liver biopsies taken from 31.4% patients who demonstrated clinical symptoms of liver damage. In 90% of cases the rejection was described as minimal or mild, and in 10% as moderate. There was no episode of severe acute rejection. Only four biopsies (10%) showed nothing but Snover triad changes. In 9 (22.5%) cases only acute rejection was diagnosed; the remaining showed in addition to acute rejection the possibility of other concomitant pathologies: viral infection in 15 cases (37.5%), biliary flow obstruction in 11 cases (28.5%), functional cholestasis in two cases (5%), and ischemic complications in three cases (7.5%).

CONCLUSIONS

Histologically confirmed acute rejection episodes were diagnosed in 14.9% liver recipients. Liver biopsy specimens, aside from Snover triad features, often showed other unspecific morphological changes. Differentiation of acute rejection from other accompanying diseases is sometimes difficult, requiring precise clinical data and pathologist experience.

Chronic allograft dysfunction: diagnosis and management. Is it always progressive?

1. There are many causes of graft dysfunction post-liver transplant, but recurrent disease remains the most common cause. 2. Viral hepatitis, nonalcoholic and alcoholic steatohepatitis, and autoimmune diseases are the most common causes of recurrent disease. 3. Graft hepatitis occurs frequently and in many cases will not progress. 4. Cirrhosis in the absence of any identifiable cause develops in a minority. 5. Treatment is of the underlying cause but some, such as recurrent and de novo autoimmune hepatitis and recurrent primary sclerosing cholangitis may not respond well, and regraft may be required.

Inhibition of mouse hepatocyte apoptosis via anti-Fas ribozyme

AIM: To investigate the effects of anti-Fas ribozyme on Fas expression and apoptosis in primary cultured mouse hepatocytes.

METHODS: Mouse hepatocytes were isolated by using collagenase irrigation. A hammerhead ribozyme targeting the Fas mRNA was constructed, and transfected into mouse hepatocytes via Effectene. Then Fas expression in mouse hepatocytes was detected by RT-PCR and western blotting. After being treated with anti-Fas antibody (JO₂), hepatocytes viability was measured with MTT assay. Caspase-3 proteolytic activity was detected, and cell apoptosis was measured according to Annexin V-FITC apoptosis detection kit.

RESULTS: Fas expressed in primary mouse hepatocytes. Fas expression in hepatocytes transfected with anti-Fas ribozyme was decreased remarkably and correlated with the resistance to Fas-mediated apoptosis as determined by flow cytometry and caspase-3 proteolytic activity.

CONCLUSION: Anti-Fas ribozyme can remarkably decrease the Fas expression in mouse hepatocytes, thus inhibit Fas-mediated apoptosis in hepatocytes. It is suggested that anti-Fas ribozyme could significantly increase the resistance of transplanted hepatocytes to apoptosis and improve the survival of transplanted hepatocytes.

Outcomes of liver transplantation for cryptogenic cirrhosis: a single-center study of 71 patients

Cryptogenic cirrhosis (CC) is emerging as an important indication for orthotoptic liver transplantation (OLT) in the United States. Our aim was to identify risk factors associated with nonalcoholic steatohepatitis (NASH) in patients with CC and to evaluate outcomes following OLT.

PATIENTS AND METHODS

A chart review was performed on patients transplanted for CC at the University of Nebraska Medical Center between October 1993 and May 2003.

RESULTS

Seventy-one patients were identified (37 were men and 34 women). Average age was 53.5 years. Mean cholesterol and triglyceride levels increased from 174.8 to 222.3 mg/dL (P <.05) and from 162.60 to 279.66 mg/dL (P <.05), respectively. The prevalence of diabetes mellitus also increased from 37.14% to 54.93% (P <.05). Incidental hepatocellular carcinoma was present in six patients and high-grade dysplasia in one patient. Steatohepatitis developed in eight patients and recurrent cryptogenic disease in four, of whom one required retransplantation for decompensated liver disease. Rejection occurred in 24 patients. Cumulative incidence of graft failure at 1 year was 4% (95% CI 0% to 10%) and at 5 years was 7% (95% CI 0% to 18%). Survival at 1 year was 85% (95% CI 77% to 94%) and at 5 years was 73% (95% CI between 61% to 86%).

CONCLUSIONS

Cryptogenic liver disease is an important cause of decompensated cirrhosis; NASH appears to be an intermediate stage in the development of this disease in a subset of patients. Short-term and 5-year survival rates in this series appear comparable to other liver transplant recipients, supporting liver transplantation as an acceptable treatment for CC.