Increased hepatocyte expression of hepatitis B virus transcription in patients with features of fibrosing cholestatic hepatitis

Hepatitis B Surface Antigen Isoforms: Their Clinical Implications, Utilisation in Diagnosis, Prevention and New Antiviral Strategies

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection-from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research.

Canonical NF-κB signaling in hepatocytes acts as a tumor-suppressor in hepatitis B virus surface antigen-driven hepatocellular carcinoma by controlling the unfolded protein response

Chronic hepatitis B virus (HBV) infection remains the most common risk factor for hepatocellular carcinoma (HCC). Efficient suppression of HBV viremia and necroinflammation as a result of nucleos(t)ide analogue treatment is able to reduce HCC incidence; nevertheless, hepatocarcinogenesis can occur in the absence of active hepatitis, correlating with high HBV surface antigen (HBsAg) levels. Nuclear factor κB (NF-κB) is a central player in chronic inflammation and HCC development. However, in the absence of severe chronic inflammation, the role of NF-κB signaling in HCC development remains elusive. As a model of hepatocarcinogenesis driven by accumulation of HBV envelope polypeptides, HBsAg transgenic mice, which show no HBV-specific immune response, were crossed to animals with hepatocyte-specific inhibition of canonical NF-κB signaling. We detected prolonged, severe endoplasmic reticulum stress already at 20 weeks of age in NF-κB-deficient hepatocytes of HBsAg-expressing mice. The unfolded protein response regulator binding immunoglobulin protein/78-kDa glucose-regulated protein was down-regulated, activating transcription factor 6, and eIF2α were activated with subsequent overexpression of CCAAT/enhancer binding protein homologous protein. Notably, immune cell infiltrates and liver transaminases were unchanged. However, as a result of this increased cellular stress, insufficient hepatocyte proliferation due to G1 /S-phase cell cycle arrest with overexpression of p27 and emergence of ductular reactions was detected. This culminated in increased DNA damage already at 20 weeks of age and finally led to 100% HCC incidence due to NF-κB inhibition.

CONCLUSION

The role of canonical NF-κB signaling in HCC development depends on the mode of liver damage; in the case of HBsAg-driven hepatocarcinogenesis, NF-κB in hepatocytes acts as a critical tumor suppressor by augmenting the endoplasmic reticulum stress response.

Hepatitis B virus large surface protein: function and fame

Chronic infection with hepatitis B virus (HBV) is the leading cause of liver cirrhosis and hepatocellular carcinoma worldwide. HBV life cycle begins with viral attachment to hepatocytes, mediated by the large HBV surface protein (LHBs). Identification of the sodium-taurocholate cotransporting polypeptide (NTCP) as a HBV receptor has revealed a suitable target for viral entry inhibition. Analysis of serum hepatitis B surface antigen (HBsAg) level is a non-invasive diagnostic parameter that improves HBV treatment opportunities. Furthermore, HBsAg plays an important role in manipulation of host immune response by HBV. However, observations in patients with chronic hepatitis B under conditions of immune suppression and in transgenic mouse models of HBV infection suggest, that in absence of adaptive immune responses cellular mechanisms induced by HBV may also lead to the development of liver diseases. Thus, the multifaceted pathological aspects of HBsAg predetermine the design of new therapeutical options modulating associated biological implications.

Hepatitis B virus PreS/S gene variants: pathobiology and clinical implications

The emergence and takeover of hepatitis B virus (HBV) variants carrying mutation(s) in the preS/S genomic region is a fairly frequent event that may occur spontaneously or may be the consequence of immunoprophylaxis or antiviral treatments. Selection of preS/S mutants may have relevant pathobiological and clinical implications. Both experimental data and studies in humans show that several specific mutations in the preS/S gene may induce an imbalance in the synthesis of the surface proteins and their consequent retention within the endoplasmic reticulum (ER) of the hepatocytes. The accumulation of mutated surface proteins may cause ER stress with the consequent induction of oxidative DNA damage and genomic instability. Viral mutants with antigenically modified surface antigen may be potentially infectious to immune-prophylaxed patients and may account for cases of occult HBV infection. In addition, preS/S variants were reported to be associated with cases of fulminant hepatitis as well as of fibrosing cholestatic hepatitis, and they are associated with cirrhosis and hepatocellular carcinoma development.

Intrahepatic cholestasis in common chronic liver diseases

BACKGROUND AND OBJECTIVE

Cholestasis represents the consequence of impaired bile formation and decrease in bile flow, generally classified as extra- and intrahepatic. Cholestasis is the pivotal hallmark of the so-called primary cholestatic liver diseases but may also emerge in other forms of chronic liver injury. The aim now was to summarise the current state of knowledge on intrahepatic cholestasis related to chronic liver diseases.

METHODS

For this overview on intrahepatic cholestasis in chronic liver disorders other than the 'classic' cholestatic liver diseases, selected references were retrieved by literature search in MEDLINE and textbooks were reviewed. All articles were selected that discussed pathophysiological and clinical aspects of intrahepatic cholestasis in the context of alcoholic liver disease, nonalcoholic fatty liver disease, chronic hepatitis B and C virus infections as well as drug-induced and granulomatous liver diseases. Titles referring to primary biliary cirrhosis and sclerosing cholangitis were excluded.

RESULTS AND CONCLUSIONS

Dependent on the aetiology, intrahepatic cholestasis is present at variable frequencies and in different disease stages in chronic liver diseases. Cholestasis secondary to chronic liver injury may denote a severe disease course and development of end-stage liver disease or specific disease variants. These findings indicate that 'secondary intrahepatic cholestasis' (SIC) can occur in the natural course of chronic liver diseases other than the primary cholestatic diseases, in particular in the setting of advanced disease progression.

Seeking beyond rejection: an update on the differential diagnosis and a practical approach to liver allograft biopsy interpretation

Pathologic evaluation of liver allograft biopsies plays an integral role in the management of patients after liver transplantation. This review summarizes the clinical context and classical histology of different types of allograft rejection and also the common entities that enter the differential diagnosis of allograft rejection, and provides practical approaches to liver allograft biopsy interpretation. In addition, some of the new developments in the field of liver transplant pathology are updated. The purpose of this review is to provide guidance for pathologists interpreting liver allograft biopsies, particularly those interested in developing expertise in the field of liver transplant pathology.

Identification of a novel hepatitis B virus precore/core deletion mutant in HIV/hepatitis B virus co-infected individuals

OBJECTIVES

Although HAART has resulted in improved health outcomes for most HIV-infected individuals, liver failure has emerged as a major cause of morbidity and mortality in people co-infected with hepatitis B virus (HBV). In HBV mono-infected individuals, core deletion mutants are associated with more aggressive liver disease. As HIV accelerates HBV liver disease progression, we hypothesized that HIV-HBV co-infected individuals have increased frequency of core mutations including deletions. To test this hypothesis, we have analysed genome-length sequences of HBV DNA from patients both prior to and during antiviral therapy.

SETTING

Prospective HIV/HBV co-infected cohort study.

METHODS

Genomic length HBV DNA was amplified by PCR from the serum samples of ten HIV/HBV co-infected individuals and five HBV mono-infected individuals prior to the commencement of lamivudine therapy and again after nine to 74 months of treatment. The complete genomes were sequenced and in order to further analyse some mutations, their frequency was determined in additional HIV/HBV co-infected and HBV mono-infected individuals.

RESULTS

A novel -1G mutation was identified in the HBV precore and overlapping core genes that truncated the deduced precore/core proteins. The mutant genome was the dominant species in some HIV/HBV co-infected individuals and was more prevalent in HIV/HBV co-infected individuals than HBV mono-infected individuals. The mutation was also associated with high HBV DNA concentrations in HIV/HBV co-infected individuals. Additional mutations were identified in the core/precore and polymerase genes and regulatory regions.

CONCLUSION

Mutations in the HBV core and precore genes may be contributing to disease pathogenesis in HIV/HBV co-infected individuals.

Histologic findings in recurrent HBV

1. The histopathologic presentation of hepatitis B (HB) infection in liver allografts is generally similar to that seen in the nonallografts. 2. An atypical pattern of recurrent HB, i.e., fibrosing cholestatic hepatitis (FCH) occurs in a small number of patients. These patients present with a severe cholestatic syndrome, which may clinically resemble acute or chronic rejection. 3. There are several other possible causes of acute and chronic hepatitis in liver allografts that may need to be considered. 4. Hepatitis B virus (HBV) infection in the liver allograft can easily be confirmed by performing immunohistochemical stains for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). The expression pattern of these HBV antigens varies and is sometimes helpful in determining whether the liver injury is mainly from the HBV or from other causes in coexistence with the HBV infection. 5. Histological grading of the necroinflammatory activity and staging of the fibrosis should only be applied when the changes are related to the recurrent HB. 6. The pathology of liver transplantation is complex; therefore, clinical correlations remain extremely important in arriving at the final and correct diagnosis.

Mutations affecting the replication capacity of the hepatitis B virus

The genetic variability of the hepatitis B virus (HBV) encounters two compounding forces: a high viral copy number produced during active replication and the lack of proofreading activity in the HBV polymerase, resulting in a high mutational rate. A large pool of quasispecies is generated in which the fittest virus, i.e. the virus that replicates best, becomes the dominant species. Immune and antiviral selection pressures result in vaccine/immunoglobulin escape mutants and antiviral resistant variants. Viruses encoding changes associated with antiviral resistance often have reduced replication in vitro, but the accumulation of additional mutations helps restore viral fitness. These compensatory mutations may occur not only in the polymerase gene but also in other genes such as the overlapping envelope gene, the precore gene, or in regulatory regions such as the basal core promoter. In this report we aim to review the new findings that have appeared in recent months.

Immune suppression uncovers endogenous cytopathic effects of the hepatitis B virus

It is generally accepted that the host's immune response rather than the virus itself is causing the hepatocellular damage seen in acute and chronic hepatitis B virus (HBV) infections. However, in situations of severe immune suppression, chronic HBV patients may develop a considerable degree of liver disease. To examine whether HBV has direct cytopathic effects in severely immune compromised hosts, we have infected severe combined immune deficient mice (uPA-SCID), harboring human liver cells, with HBV. Serologic analysis of the plasma of HBV-infected animals revealed the presence of extremely high amounts of viral genomes and proteins. Histological analysis of the livers of uPA-SCID chimeras infected with HBV for more than 2 months showed that the majority of human hepatocytes had a ground-glass appearance, stained intensely for viral proteins, and showed signs of considerable damage and cell death. This histopathologic pattern closely resembles the picture observed in the livers of immunosuppressed HBV patients. These lesions were not observed in animals infected with HBV for less than 1 month. Ultrastructural analysis of long-term-infected hepatocytes showed a highly increased presence of cylindrical HBsAg structures, core particles, and Dane particles compared to short-term-infected hepatocytes. These long-term-infected hepatocytes also contained elevated amounts of HBV cccDNA. In conclusion, HBV causes dramatic intracellular changes and hepatocellular damage in the human hepatocytes that reside in a severely immune deficient mouse. These lesions show much resemblance to the ones encountered in immunosuppressed chronic HBV patients. Our observations indicate that HBV may be directly cytopathic in conditions of severe immune suppression.

Hepatitis B reactivation in patients positive for hepatitis B surface antigen undergoing autologous hematopoietic cell transplantation

Hepatitis due to reactivation of hepatitis B virus is an important cause of liver-related morbidity and mortality in hepatitis B surface antigen (HBsAg) positive patients undergoing autologous hematopoeitic cell transplantation. With the recent introduction of sensitive serum HBV DNA quantitation assay, the diagnosis of hepatitis B reactivation can now be made more reliably. As these hepatitis are driven by the host immune response to a surge of hepatitis B viral load, the availability of effective nucleoside analogues which can inhibit hepatitis B viral replication has opened up new approaches to this previously untreatable condition. Up till now, two such nucleoside analogues, lamivudine and adefovir dipivoxil, have been approved for the treatment of chronic hepatitis B infection. However, further studies are needed to determine which nucleoside analogues should be chosen in this transplant setting. Due to the high dose chemotherapy generally needed in autologous hematopoeitic cell transplantation, there is a high risk of post-transplant hepatitis B reactivation. Hence, all HBsAg positive patients undergoing autologous hematopoeitic cell transplantation should preferably be treated pre-emptively with nucleoside analogous. An alternative approach is to defer treatment with nucleoside analogous until there is evidence of hepatitis B virological reactivation. However, the latter approach would need the patient's hepatitis B viral load be monitored at a very close interval and might not be cost-effective.

Cellular vacuolization and apoptosis induced by hepatitis B virus large surface protein

Fibrosing cholestatic hepatitis (FCH) is a rapidly progressive form of viral hepatitis B that occurs in severely immunosuppressed patients. Pathologically, the liver in FCH is characterized by widespread hepatocyte vacuolization and apoptosis, which, in contrast to more common forms of hepatitis B, is only rarely associated with significant inflammation. Therefore, it has been proposed that, in FCH, hepatocytes may be injured by a direct cytopathic effect of the virus rather than by the host immune response. In support of this hypothesis, we present evidence that cultured hepatoma cells that had been transfected with a plasmid selectively expressing the viral large surface protein form numerous large vacuoles and undergo apoptosis. The similarity of the cytopathology in FCH in vivo and in these transfected cells in vitro strongly implicates the large surface protein as the direct cause of this acute liver disease. This conclusion is further supported by the published demonstration that hepatocytes tend to accumulate large surface protein in FCH, which may reflect its overexpression by the virus. In conclusion, our data implicate the large surface protein as a major cause of hepatocyte injury in fibrosing cholestatic hepatitis.

Hepatitis B: progress in the last 15 years

1. Patients undergoing orthotopic liver transplantation (OLT) for hepatitis B without effective prophylaxis have a high risk for recurrent infection and severe graft damage, leading to death or re-OLT. 2. Long-term prophylaxis with hepatitis B immune globulin (HBIg) significantly reduces the risk for hepatitis B virus (HBV) recurrence and increases survival. Patients with detectable HBV DNA at the time of OLT have a high risk for recurrence despite HBIg prophylaxis. 3. Lamivudine (LAM) therapy for patients with decompensated HBV cirrhosis before OLT results in inhibition of viral replication and clinical improvement. Its efficacy is limited by the frequent emergence of LAM-resistant YMDD mutations. The ideal length of therapy with LAM pre-OLT has not yet been defined. 4. Prophylaxis of HBV recurrence with LAM monotherapy is not recommended because of the reappearance of hepatitis B surface antigen after OLT in approximately 50% of patients. 5. LAM is the best available treatment for patients with established recurrent hepatitis B. Long-term therapy is associated with the emergence of drug-resistant mutants in up to 60% of patients. Severe hepatitis and liver failure have been described among liver transplant recipients with YMDD mutations. 6. Combination therapy with HBIg and LAM prevents HBV recurrence in 90% to 100% of patients who undergo OLT for hepatitis B. The optimal HBIg protocol in the LAM era is yet to be defined. 7. Preliminary studies suggest that adefovir dipivoxil inhibits HBV replication in patients infected with LAM-resistant HBV strains. 8. Fifteen years ago, hepatitis B was regarded as a relative or absolute contraindication for OLT. Today, hepatitis B is a universally accepted indication for OLT.

Reactivation of replication of hepatitis B and C viruses after immunosuppressive therapy: an unresolved issue

The liver is susceptible to the toxic effects of many cytotoxic or immunosuppressive treatments. However, in carriers of hepatitis B virus (HBV) and, less frequently, of hepatitis C virus, liver damage due to reactivation of viral replication can occur after withdrawal of immunosuppressive drugs. These reactivations, which are associated with fulminant forms of hepatitis in up to 25% of cases, are observed both in symptom-free chronic carriers of hepatitis B surface antigen and in patients who have chronic hepatitis B or C and concurrent haematological tumours or solid neoplasms or who have received transplants. HBV-related complications may cause delays or modifications of therapy, and the chance of cure is reduced. In this review, we analyse clinical, biochemical, and serological issues in reactivation of viral replication and examine the role of immune reactions in the pathogenesis and the possible toxicity of immunosuppressive drugs. We emphasise the importance of identifying predictive markers of a clinically relevant reactivation, review difficulties in drug prevention and treatment, indicate studies that are needed to address the key clinical issues, and give practical recommendations to practising physicians and oncologists.

Diagnostic issues in liver transplantation pathology

Liver biopsy is used to determine the pathogenesis of liver dysfunction after liver transplantation. One or more causative factors may be identified on biopsy. The pathologist must be familiar with the histopathology of acute rejection to differentiate it from other potential complications, including biliary obstruction, intercurrent cytomegalovirus hepatitis, or recurrent disease. Consensus documents from the Banff international panel provide useful guidelines for the appropriate grading of acute and chronic rejection.

Timing of reinfection and mechanisms of hepatocellular damage in transplanted hepatitis C virus-reinfected liver

Pathogenic mechanisms and dynamics of hepatitis C virus (HCV) reinfection in orthotopic liver transplantation (OLT) are poorly defined. This study focuses on these aspects by studying 55 frozen biopsy specimens from transplant recipients with various histological diagnoses obtained from 4 days to 4 years post-OLT and 10 patients with HCV-related chronic hepatitis. The percentage of HCV-infected hepatocytes, number and distribution of CD8 and natural killer cells, and rates of hepatocellular apoptosis and proliferation were quantified by immunohistochemistry. HCV antigens were detected in 37% of biopsy specimens obtained within 20 days and 90% of biopsy specimens obtained from 21 days to 6 months after OLT. The number of HCV-infected hepatocytes was never less than 40% in acute hepatitis specimens and never greater than 30% in the other cases. Hepatocellular apoptosis was high in biopsy specimens of acute hepatitis and moderate in those from transplant recipients with normal histological characteristics, but still greater than in specimens of chronic active hepatitis. Proliferation correlated significantly with apoptosis. Lymphocyte infiltration was high and similar among cases of acute hepatitis, chronic hepatitis, and rejection. These data: (1) show that the detection of liver HCV antigens is sensitive enough to be used in clinical practice as a diagnostic tool to detect infection of the transplanted liver and might be useful, combined with conventional histological evaluation to detect hepatitic damage, for therapeutic decision making; (2) suggest direct cytotoxicity of HCV, as well as immunologic mechanisms possibly prevalent in chronic hepatitis and rejection, at least in the phase of acute massive liver infection; and (3) show that hepatocellular apoptosis and regeneration might be active enough to lead to replacement of the entire transplanted liver in 2 weeks.

Acute flares in chronic hepatitis B: the natural and unnatural history of an immunologically mediated liver disease

Acute flares in chronic hepatitis B are common and may be caused by a number of identifiable and potentially treatable factors. The common link for many of these exacerbation episodes is a change in the immunologic response to hepatitis B virus (HBV), and this may have no identifiable cause or be triggered by an increase in viral replication or genotypic change. It is important to keep in mind the clinical situations in which patients are at increased risk of reactivated infection and secondary exacerbations. Reactivation is frequently induced by medical treatments such as cancer chemotherapy, antirejection drugs used in organ transplantation, and corticosteroids. The immunologic flares that often result from sudden withdrawal of these medications can be life-threatening unless recognized and treated promptly with antivirals, and there is increasing experience that preemptive antiviral treatment can diminish their occurrence and improve the outcome. The experience with lamivudine and other nucleoside analogues has increased our understanding of the molecular events behind hepatitis flares that occur when chronic hepatitis B is treated with drugs that potently inhibit HBV DNA polymerase. However, not all flares are explainable by events related to HBV infection alone. Depending on the population studied, as many as 20%-30% of flares may be caused by infection with other hepatotropic viruses, and this situation may inhibit HBV replication. Proper understanding of the etiology and effective treatment of acute flares in chronic hepatitis B requires an appreciation of high-risk clinical situations, assessment of HBV replication status, and testing for other viruses when appropriate.

Post-transplant quasispecies pattern remains stable over time in patients with recurrent cholestatic hepatitis due to hepatitis C virus

BACKGROUND/AIMS

Several studies have shown that cholestatic recurrent hepatitis is associated with very high HCV RNA loads in liver transplant recipients. The aim of this study was to investigate whether a correlation exists between cholestatic hepatitis post-transplant and the population of viral quasispecies.

METHODS

One hundred and nine serial sera samples were tested from 15 recurrent HCV patients. Four of these patients showed severe cholestatic recurrent hepatitis, 11 patients demonstrated non-cholestatic recurrent hepatitis post-transplant. Quasispecies were detected by RT-PCR amplification of the HVR1 followed by single-stranded conformational polymorphism analysis.

RESULTS

Forty-one samples from four cholestatic patients were tested. All four patients showed very stable quasispecies patterns post-transplant. One cholestatic patient also showed a stable quasispecies band pattern following retransplantation, again associated with severe cholestatic hepatitis. Sixty-eight samples were tested from the 11 non-cholestatic patients. In contrast, these patients showed significantly more quasispecies bands than the cholestatic patients. The noncholestatic patients also displayed fluctuating band patterns post-transplant. Serial samples were tested after retransplantation in one non-cholestatic patient, with a fluctuating pattern again seen. There was a negative correlation between the HCV RNA load in serum and the number of quasispecies bands.

CONCLUSIONS

Stable hepatitis C viral quasispecies associated with persistently high viral load in post-transplant cholestatic hepatitis suggest that viral escape from immune pressures may play a role in the pathogenesis of this condition.

Intrahepatic cholestasis following liver transplantation

Intrahepatic cholestasis following liver transplantation commonly occurs after liver transplantation and may be caused by infections, drugs such as cyclosporine and sulfonamides, and acute or chronic rejection. Less common causes such as fibrosing cholestatic hepatitis or recurrent primary biliary cirrhosis or primary sclerosing cholangitis may also be encountered. Biliary strictures may also be present. Although some disorders may be managed medically, others often require repeat liver transplantation. Prompt recognition and specific treatment can improve the outcome for liver transplant recipients.

Fibrosing cholestatic hepatitis in renal transplant recipients with hepatitis C virus infection

Fibrosing cholestatic hepatitis (FCH) has been described as a specific manifestation of hepatitis B virus (HBV) infection in liver allograft recipients characterized by a rapid progression to liver failure. Only sporadic cases have been reported in other immunocompromised groups infected with HBV and in a few transplant recipients with hepatitis C virus (HCV) infection. We present the occurrence of FCH in 4 HCV-infected renal transplant recipients within a series of 73 renal transplant recipients with HCV infection followed up closely serologically and with consecutive liver biopsies. All 4 patients received the triple-immunosuppressive regimen (azathioprine, cyclosporine A, methylprednisolone). The interval from transplantation to the appearance of liver dysfunction was 1 to 4 months and to histological diagnosis, 3 to 11 months. The biochemical profile was analogous to a progressive cholestatic syndrome in 3 patients, whereas the fourth patient had only slightly increased alanine aminotransferase and gamma-glutamyl transferase (gammaGT) levels. Liver histological examination showed the characteristic pattern of FCH in 2 patients, whereas the other 2 patients had changes compatible with an early stage. All patients were anti-HCV negative at the time of transplantation, whereas 2 patients, 1 with incomplete and 1with complete histological FCH features, seroconverted after 3 and 31 months, respectively. The patients were HCV RNA positive at the time of the first liver biopsy and showed high serum HCV RNA levels (14 to 58 x 10(6) Eq/mL, branched DNA). HCV genotype was 1b in 3 patients and 3a in 1 patient. After histological diagnosis, immunosuppression was drastically reduced. Two patients died of sepsis and liver failure 16 and 18 months posttransplantation, whereas the seroconverted patients showed marked improvement of their liver disease, which was histologically verified in 1 patient. In conclusion, FCH can occur in HCV-infected renal transplant recipients. It seems to develop as a complication of a recent HCV infection during the period of maximal immunosuppression and is associated with high HCV viremia levels. There are indications that drastic reduction of immunosuppression may have a beneficial effect on the outcome of the disease.

Fibrosing cholestatic hepatitis after living related-donor renal transplantation

A 43-year-old man underwent living related-donor renal transplantation because of chronic renal failure in 1991. During the transplant period, both donor and recipient were seronegative for hepatitis B surface antigen (HBsAg). The donor was seropositive for antibody to hepatitis B surface antigen (anti-HBs) due to hepatitis B virus (HBV) vaccination. After transplantation, FK506 and methylprednisolone had been administered to the patient as immunosuppressants. In 1993, HBsAg appeared in his serum. His alanine aminotransferase level elevated gradually during 1995 and then in 1996, general fatigue, ascites and jaundice developed. At this time his serum was positive for hepatitis B e antibody, contained more than 100000 Meq/mL HBV-DNA and 100% precore mutant. Despite subsequent intensive therapy, liver dysfunction progressed and this patient died of hepatic failure 2 months following admission. At autopsy, the liver exhibited cholestasis, fibrosis extending from the portal tracts, mild inflammation and hepatocytes with a ground-glass appearance. In addition, HBsAg and hepatitis B core antigens had accumulated in the hepatocytes. Consequently, the final diagnosis was fibrosing cholestatic hepatitis (FCH) due to precore mutant HBV infection contracted after renal transplantation. It is unclear when and where the recipient liver became HBV infected. Nevertheless, after renal transplantation, while receiving immunosuppressive drugs, HBV appeared to have the potential to cause hepatic failure and FCH may have been a fatal complication for the recipient.

Treatment of fibrosing cholestatic hepatitis with lamivudine

Fibrosing cholestatic hepatitis is a histological variant of hepatitis B virus infection with a high rate of mortality. We describe a patient who acquired acute hepatitis B virus infection 8 months after renal transplantation. Clinical features of rapidly progressive liver failure, indicated by prolonged prothrombin time (57 seconds) and increased bilirubin (40.4 mg/dL) and ammonia (129 mumol/L) concentrations, were accompanied by an extremely high serum HBV DNA level (2.153 x 10(6) pg/mL). Liver biopsy specimen showed fibrosing cholestatic hepatitis with widespread balloon degeneration of hepatocytes, focal hepatocyte loss, bile stasis, periportal fibrosis, mild lymphocytic infiltration, and strongly positive immunohistochemical staining for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen. Lamivudine therapy suppressed HBV DNA to < 10 pg/mL within 4 weeks, which was followed by gradual recovery of liver function from a state of hepatic precoma. Twenty-four months after the onset of hepatitis, the patient had normal prothrombin time and bilirubin, transaminase, and albumin levels. She remained HBsAg positive and hepatitis B e antigen negative. Renal allograft function was stable, with a creatinine level of 1.52 mg/dL. HBV DNA remained suppressed after 22 months of lamivudine therapy. Our experience shows that fibrosing cholestatic hepatitis and liver failure caused by HBV infection can be successfully treated with lamivudine.

Nucleoside analogue therapy in fibrosing cholestatic hepatitis--a case report in an HBsAg positive renal transplant recipient

A 45-year-old HBsAg carrier (HBeAb positive with normal liver function tests) underwent renal transplantation for mesangioproliferative glomerulonephritis. Sixteen months later he developed jaundice. Investigations showed he remained HBeAb positive, but HBV-DNA levels were 99 pg/ml, indicating active replication of a HBV pre-core mutant. He was commenced on lamivudine therapy with a subsequent rapid fall in HBV-DNA levels to 2.8 pg/ml, but liver function tests continued to deteriorate and he developed hepatorenal failure. Liver biopsy showed fibrosing cholestatic hepatitis. He underwent liver transplantation, which was complicated by lactic acidosis. Lamivudine was withdrawn and HBV prophylaxis with HB immunoglobulin was commenced. Unfortunately he died 38 days post-transplant of surgical complications with no evidence of HBV recurrence. We discuss the use of nucleoside analogues in fibrosing cholestatic hepatitis and review the literature.

Histopathology and pathobiology of hepatotropic virus-induced liver injury

The present report concerns current knowledge regarding immunopathogenesis that can be applied in the interpretation of histopathological changes in acute and chronic viral hepatitis. The histopathological features of viral hepatitis have not been changed and light microscopic examination remains essential for making a diagnosis and classification of chronic hepatitis and for the provision of objective parameters on grading and staging. However, new understanding and knowledge of viral pathogenesis, host immune responses, the biological behaviour of the causative viral agents and, in particular, viral interference in multiple hepatotropic viral infections must be taken into consideration in the interpretation of histopathological and immunopathological findings of liver tissues. This report also presents some histopathological analyses on multiple hepatotropic viral infections. It can be concluded that the diagnostic histological criteria for acute hepatitis remain applicable in such settings. However, the cause of acute flare up in chronic hepatitis could not be determined without clinical, virological and serological information. Routine histopathology cannot distinguish a new infection from an acute exacerbation due to a high level of viral replication or mutant virus. A repertoire of immunocytochemical stainings for viral antigens is helpful, but caution must be exercised in suggesting a specific viral aetiology due to the fact that suppression of pre-existing viral antigens can be pronounced when the new or concurrent infection is hepatitis C virus related.

Alteration of the dismal natural history of fibrosing cholestatic hepatitis secondary to hepatitis B virus with the use of lamivudine

BACKGROUND

Fibrosing cholestatic hepatitis (FCH) is a severe form of hepatitis B virus (HBV) infection occurring as either primary allograft reinfection after liver transplantation for HBV or as severe HBV reactivation induced by immunosuppression in patients with previously latent infection. Without treatment, FCH is universally fatal within a few months of diagnosis. Some improvement has been reported with long-term ganciclovir, with and without foscarnet, but an effective and easily available treatment has not yet been reported.

METHODS

We report the prolonged survival of a renal transplant recipient who developed histologically confirmed FCH 6 months after transplantation and was treated with lamivudine.

RESULTS

At the time of diagnosis, the patient had jaundice, ascites, and a serum HBV-DNA level of 3868 pg/ml. Lamivudine was instituted 2 months later, and after 6 months of treatment, the HBV-DNA level was undetectable with the serum bilirubin within the normal range. Twelve months after the diagnosis of FCH, the patient remains stable without progression of liver dysfunction.

CONCLUSION

Our experience demonstrates that lamivudine therapy can improve the dismal natural history of FCH.

Hepatitis B virus sequence changes evolving in liver transplant recipients with fulminant hepatitis

BACKGROUND/AIMS

Patients undergoing liver transplantation for hepatitis B virus (HBV) related liver cirrhosis are at major risk of developing HBV recurrence, and occasionally fulminant hepatitis. Here we tested in a longitudinal study whether specific viral variants are associated with fulminant HBV infection in the graft.

METHODS

The complete HBV genomes isolated from the sera of three patients with HBV and HBV and hepatitis delta virus (HDV) coinfection during chronic infection before and during fulminant reinfection after transplantation were amplified and directly sequenced.

RESULTS

Twenty, 25 and 19 mutations, distributed over the entire genome, were identified which differed between the HBV genomes isolated from each patient during chronic and fulminant infection, respectively. This reflects a much higher rate of nucleotide sequence changes than expected from the natural variation of HBV. No common HBV mutation emerged in any of the three cases during fulminant infection. However, precore defective viruses were found to be present in all three patients at the time of fulminant infection and in two of the patients before fulminant infection. Two of the patients had preS2-defective HBVs both before and after transplantation. A point mutation in the 'a'-determinant of the surface protein emerged in one case after transplantation under treatment with polyclonal HBV specific immunoglobulins.

CONCLUSIONS

Many new, but no specific common mutations emerged during fulminant HBV reinfection. Although HBeAg defective variants were found in all cases studied, the presence of these variants also during chronic infection in two cases demonstrates that they are not sufficient to cause fulminant hepatitis. Thus, other factors than the emergence of a specific viral strain seem to contribute to the development of fulminant reinfection in a liver graft.

Review: hepatitis B and liver transplantation

Liver transplantation in hepatitis B virus (HBV)-infected patients is very commonly followed by recurrence of infection in the transplanted liver. Most recipients with HBV recurrence will develop chronic hepatitis that follows a more aggressive course than is seen in non-immuno-compromized subjects and this frequently results in graft failure. The presence of hepatitis B e antigen or significant levels of HBV-DNA in the serum is highly predictive of recurrence and this has led to the view that patients, whose serum is positive for these conventional markers of replication, should be excluded from transplantation. The key to improving the results of transplantation in patients with HBV infection lies in the development of effective strategies to prevent reinfection. High dose anti-HBs immunoglobulin is effective in patients who are coinfected with hepatitis D, those transplanted for fulminant hepatitis and cirrhotic patients who have very low levels of viral replication prior to transplantation. Unfortunately, immunoprophylaxis does not seem to influence the outcome in those patients with higher levels of replication. There are several new orally active nucleoside analogues that and potent inhibitors of hepatitis B replication that may be effective for both the prevention and treatment of recurrent disease. The most promising are lamivudine (2',3',dideoxy,3',thiacytidine) and famciclovir (a guanosine analogue). Both agents have been extensively evaluated in animal models of HBV and have been shown to rapidly suppress viral replication. The initial experience with these agents in liver transplant recipients has been promising and a number of studies are currently underway to determine whether these drugs, used alone or in combination with immunoprophylaxis, are able to prevent recurrence in those patients at highest risk of post-transplant HBV recurrence.

Fibrosing cholestatic hepatitis in renal transplant recipients

Fibrosing cholestatic hepatitis in a specific histologic manifestation of hepatitis B virus infection consisting of periportal fibrosis, hepatocyte ballooning, cholestasis, a relatively scant inflammatory infiltrate, and marked overexpression of hepatitis B viral antigens in hepatocytes. Until recently, fibrosing cholestatic hepatitis had been reported only in recipients of liver allografts. In this report, we present two patient in whom this lesion developed following renal transplantation. Both patients had previous liver biopsies showing relatively mild histologic changes. In one patient, the lesion developed early after retransplantation, during the period of maximal immunosuppression. However, in the second patient this lesion developed after withdrawal of immunosuppression. In both cases, death occurred within a few months because of progressive liver disease. Since this lesion can develop in "relatively healthy" hepatitis B carriers following transplantation of organs other than liver, these patients should have careful monitoring of their liver disease. Moreover, since the disease may progress despite withdrawal of immunosuppression, these patients would clearly benefit from the development of more effective therapies for posttransplant hepatitis B.

Low-dose, titratable interferon alfa in decompensated liver disease caused by chronic infection with hepatitis B virus

BACKGROUND & AIMS

Interferon therapy has been associated with a number of severe side effects when administered to patients with decompensated cirrhosis caused by chronic hepatitis B. The safety and potential efficacy of a low-dose, titratable regimen of interferon alfa-2b in patients with decompensated liver disease caused by chronic hepatitis B virus infection were studied.

METHODS

Twenty-six patients were treated at five medical centers. Five patients had Child's class A status, 15 had Child's B status, and 6 had Child's C status. Treatment was continued for 24 weeks whenever possible. Dose adjustments were made according to predefined safety criteria.

RESULTS

All patients with Child's A status responded with a sustained loss of serum hepatitis B virus DNA, reduction in aminotransferase activity, and clinical stabilization. Only 5 patients with Child's B (33%) and no patients with Child's C status reached similar end points. The probability of survival was greater in responders than in nonresponders (P = 0.017). Three patients each developed serious infections or greater than twofold increases in serum aminotransferase levels during therapy.

CONCLUSIONS

Low-dose, titratable interferon therapy is safer than previously reported regimens. Nonetheless, serious infections were observed relatively frequently, and this therapy should be reserved for individuals with mild to moderate hepatic decompensation, preferably patients with Child's A status.

Fibrosing cholestatic hepatitis in a renal transplant recipient associated with the hepatitis B virus precore mutant

A patient with evidence of chronic infection with hepatitis B virus (seropositive for hepatitis B surface antigen, and with antibody to hepatitis B e antigen) underwent renal transplantation, which subsequently failed. The patient developed abnormal liver function tests and 8 months after the removal of the transplanted kidney, hepatitis B virus DNA was detected in the serum in the absence of hepatitis B e antigen. Liver biopsy revealed the presence of fibrosing cholestatic hepatitis. Sequence analysis of the serum hepatitis B virus DNA showed the presence of the pre-core mutant. This case shows that fibrosing cholestatic hepatitis can occur outside the setting of liver transplantation, and coincided with the development of the pre-core mutant of hepatitis B virus.

Hepatitis B virus precore mutant infection is associated with severe recurrent disease after liver transplantation

The factors that predispose patients undergoing liver transplantation for hepatitis B virus (HBV) disease to severe recurrence of infection are unclear. In this study we examined the effect of pretransplantation infection with HBV and precore variant strains of HBV on posttransplantation outcome and allograft histology in 24 patients who survived more than 3 months after liver transplantation. Based on pretransplantation serum HBV DNA status as detected by the polymerase chain reaction (PCR) and direct sequencing, the 24 patients could be assigned to three groups. In group 1 there were 4 patients HBV DNA-negative before transplantation and none of these patients suffered recurrence of infection posttransplantation. In group 2, of 10 patients with pretransplantation infection with wild-type virus, 7 became reinfected, and 1 of these developed HBV-related graft failure. In group 3, 9 of 10 patients infected with precore mutant HBV strains became reinfected. However, in contrast to the patients in group 2, 7 patients in group 3 developed HBV-related graft loss, and 5 of these patients had fibrosing cholestatic hepatitis (FCH). These results indicate that infection with precore mutant strains of HBV predisposes a patient to early graft loss following transplantation.

Hepatitis B-associated liver cirrhosis as an indication for liver transplantation

Fourteen HBsAg-positive patients received a liver transplant in Groningen. Two were HBeAg-positive and 12 HBeAg-negative. No anti-HBs immunoglobulin was given at the time. Both HBeAg-positive and 9 of 12 of the HBeAg-negative patients became HBsAg-positive again after transplantation. Virus titers were tested in eight patients. Two HBeAg-negative patients were HBV-DNA-negative at transplantation and are still HBV-DNA-negative one-and-half-years after transplantation, both by the branched DNA hybridization technique and by PCR (cut-off values 0.7 x 10(6) and 10(3) HBV genomes/ml, respectively). One patient who had a low HBV-DNA titer at transplantation remained PCR-positive thereafter, but became HBsAg-negative. All other patients were HBV-DNA-positive and had a recurrence that rapidly led to high HBV titers. The liver histology was characterized by fibrosis and cirrhosis, centrilobular cholestasis and high expression of HBsAg and HBcAg, but with little inflammatory infiltrate. We conclude from these results that without anti-HBs immunoglobulin prophylaxis there is a high rate of HBV recurrence after transplantation. The current policy is that patients who test negative in the HBV-DNA dot-blot assay (< 10(7) genomes/ml) are transplantation candidates and are treated with high-dose anti-HBs immunoglobulin after transplantation. HBV-DNA-positive patients (> 10(7) genomes/ml) remain poor candidates for liver transplantation, even with anti-HBs immunoprophylaxis.

Precore and contiguous regions of hepatitis B virus in liver transplantation for end-stage hepatitis B

BACKGROUND/AIMS

Recurrent hepatitis B virus (HBV) infection is the leading cause of mortality and morbidity after orthotopic liver transplantation (OLT) for HBV-related liver disease, but the extent of viral genetic variation in this setting remains unknown.

METHODS

Eight patients who underwent OLT for HBV-related liver disease were studied; 7 had cirrhosis and 1 had fulminant hepatitis. Four patients received long-term hepatitis B immunoglobulin prophylaxis. A 240-base pair fragment (1742-1981) comprising the precore region of HBV was amplified by polymerase chain reaction from sera drawn before OLT and 6, 12, and 24 months after OLT and analyzed.

RESULTS

All sera were positive by polymerase chain reaction. Nucleotide sequence variations were congruent within most patients before and after OLT; however, in one patient, substantial sequence variation was observed, suggesting infection with a new HBV strain. No sequence variation associated with a particular outcome could be identified. Two patients harbored HBV variants with a deletion or insertion upstream of the precore messenger RNA initiation site.

CONCLUSIONS

Reinfection after OLT can occasionally be caused by HBV strains different from the one present before OLT. Changes within the sequenced region are not predictive of the outcome of reinfection.

Fibrosing cholestatic hepatitis in a hepatitis B surface antigen carrier after renal transplantation

A 45-year-old hepatitis B surface antigen carrier had an allograft kidney transplantation and maintenance immunosuppression with cyclosporin A and prednisolone. Six months later, she experienced a rapidly progressive hepatic failure manifested by elevation of serum bilirubin level, prolongation of prothrombin time, and mild to modest increase of serum aminotransferase levels. She died in 6 weeks. Postmortem liver histology showed canalicular and cellular cholestasis and ground-glass appearance and ballooning of most hepatocytes, but only mild inflammatory cell infiltration. Immunohistochemical staining showed massive loads of hepatitis B surface and core antigens in the hepatocytes and extensive periportal fibrosis. The whole picture was compatible with fibrosing cholestatic hepatitis described in hepatitis B virus-infected liver transplant. Sequencing of the hepatitis B virus genome amplified from the patient's serum indicated a precore mutant but few mutations in the core, pre-S, and S genes. Little inflammatory reaction was observed histologically despite HLA compatibility, a situation differing from that in liver transplant. This observation indicates that fibrosing cholestatic hepatitis may also occur in non-liver transplant setting.

Hepatitis B virus replication in diverse cell types during chronic hepatitis B virus infection

Hepatitis B virus-specific nucleic acid sequences and proteins have been detected in extrahepatic tissues of acutely and chronically infected patients. However, apart from peripheral blood mononuclear cells and bone marrow cells, little is known about the specific cell types that permit viral replication. In this study, we assessed the extrahepatic tissues of four patients who died with chronic hepatitis B virus infection and two uninfected controls by means of in situ hybridization and immunohistochemical study. Three of these patients had diffuse extrahepatic distribution of the virus. Hepatitis B virus nucleic acid sequences and proteins were detected in the lymph nodes, spleen, bone marrow, kidney, skin, colon, stomach, testes and periadrenal ganglia. The following cell types were found to be positive for hepatitis B virus: endothelial cells, macrophages/monocytes, hematopoietic precursors, basal keratinocytes, mucosal epithelial cells, stromal fibroblasts and sustentacular and neuronal cells. It is probable that these cells could support viral replication because hepatitis B virus DNA replicative intermediates, viral transcripts and HBsAg and HBcAg proteins were detected in most. These findings may be relevant to the initiation of extrahepatic syndromes associated with chronic hepatitis B virus infection such as vasculitis, glomerulonephropathy, neuropathy and dermatitis.