[Drug induced liver injury]. / Medikamentös-toxische Lebererkrankungen.

The incidence of drug induced liver injury (DILI) has been reported to be between 14 - 20 per 100 000 inhabitants. The diagnosis of DILI is based on an accurate anamnesis and exclusion of other liver diseases. Drugs most commonly involved in DILI belong to the classes of antibiotics and analgetics. The most important therapeutic issue is to identify and withdraw the toxic compound.

Early mortality and long-term survival after abdominal surgery in patients with liver cirrhosis.

BACKGROUND: Patients with liver cirrhosis have an increased risk of postoperative mortality. In addition, cirrhotic patients per se have a reduced life expectancy. Little is known about the combined effect of these factors on long-term outcomes after surgery. We thus evaluated early -and long-term survival in patients with cirrhosis who underwent abdominal surgery. METHODS: We evaluated 30- and 90-day mortality as well as long-term survival after 212 general surgical procedures performed in 194 patients with liver cirrhosis. Risk factors for early and late mortality were assessed by uni- and multivariate methods. To avoid multicollinearity of data, different models (Child Turcotte Pugh [CTP], model for end-stage liver disease [MELD], or American Society of Anesthesiologists [ASA] score) were used in multivariate analysis. RESULTS: The 30- and 90-day mortality rates were 20% and 30%, respectively. CTP, MELD, and ASA were all independently associated with 30- and 90-day mortality. Although emergency operations and intraoperative transfusions independently influenced 30-day mortality, 90-day mortality also was influenced by the extent of the procedure and thrombocytopenia. Survival after surgery (n = 180) was 54% after one and 25% after 5 years (median survival 1.24 years). Long-term survival was independently influenced by CTP, MELD, ASA, hyponatremia, emergency operations, thrombocytopenia, and underlying malignancies. Survival in patients discharged after surgery (n = 140) was 69% after 1 and 33% after 5 years (median survival 2.8 years). Survival after discharge was independently influenced by MELD, CTP, hyponatremia, underlying malignant disease, and (partially) by serum creatinine. The inclusion of serum sodium into MELD scores did not further facilitate prediction of early and late mortality. CONCLUSION: A high postoperative mortality as well as a strongly reduced survival even after hospital discharge contribute to the very poor life expectancy in patients with liver cirrhosis requiring general surgery. Postoperative outcome is influenced by liver function, comorbidity and "surgical" factors such as the need for blood transfusion and emergent or major operations. However, after hospital discharge, "surgical" factors did not influence survival.

Immunobiology of hepatocellular carcinoma.

INTRODUCTION: Hepatocellular carcinoma (HCC) is a tumor of increasing incidence and high mortality worldwide. Diagnosis of HCC is often difficult, especially at early stages of disease. Additionally, current treatment options are limited. HCC usually develops in an environment of chronic liver disease. The immune system has an important role in shaping this environment, especially in chronic viral hepatitis, the leading cause of HCC. However, the immune system also plays a role in natural immunity against HCC although this is apparently not sufficient to control the majority of tumors. This failure in tumor control is due to multiple immunomodulatory mechanisms employed by HCC to subvert the immune system. In this review, we will summarize the current knowledge about the role of the immune system in hepatocarcinogenesis. Additionally, we will describe the mechanisms used by the immune system to control established lesions and the reasons why these immune responses apparently fail so often. Finally, possible implications for the design of novel immunotherapeutic strategies will be discussed.

[Inherited disorders of liver metabolism]. / Hereditäre Lebererkrankungen.

Inherited disorders of liver metabolism are in general due to single enzyme defects that result in abnormalities in the synthesis or catabolism of proteins, carbohydrates, or lipids. This group of diseases comprises disorders of the amino acid, iron, bilirubin and sphingolipid metabolism as well as disorders of the coagulation cascade, the urea cycle and diverse transport processes. These diseases either lead to structural liver damage or, if the defective enzyme is produced predominantly in the liver, to injury to other organ systems. In this review article, we discuss the pathogenesis, clinical presentation, diagnosis and therapy of hereditary hemochromatosis, Wilson's disease and alpha1-antitrypsin-deficiency which represent the most common hereditary liver diseases.

Lack of ex vivo peripheral and intrahepatic α-fetoprotein-specific CD4+ responses in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignancies with a poor prognosis and limited therapeutic options that is often characterized by the expression of the tumor-associated antigen α-fetoprotein (AFP). CD4+ helper T cells are important in generating potent anticancer immunity as they prime and expand CD8+ T-cell memory and may also have direct antitumor activity. However, very little information is currently available about the relative frequency, immunodominance and peripheral versus intratumoral distribution of AFP-specific CD4+ T-cell responses in patients with HCC. We, therefore, analyzed AFP-specific CD4+ responses in blood and tumor tissue of patients with HCC by using overlapping peptides spanning the entire AFP protein and novel sensitive approaches such as antigen-specific upregulation of CD154. We found that AFP-specific CD4+ T-cell responses were not detectable in the peripheral blood ex vivo. However, after in vitro stimulation, AFP-specific CD4+ T-cell responses were detectable in a large fraction of patients targeting different previously unreported epitopes with no clear immunodominance. These results indicate that AFP-specific CD4+ T-cell responses are not completely deleted but only present at very low frequencies. Importantly, AFP-specific CD4+ T-cell responses were also rarely detectable in tumor tissue, suggesting that the relative absence of these cells in the circulation ex vivo is not due to a rapid accumulation to the tumor side. Taken together, these results suggest that the lack of sufficient CD4+ T-cell help, especially within the tumor tissue, may be one central mechanism responsible for the failure of AFP-specific immune responses to control HCC progression.

Perioperative mortality after non-hepatic general surgery in patients with liver cirrhosis: an analysis of 138 operations in the 2000s using Child and MELD scores.

INTRODUCTION: Despite of advances in modern surgical and intensive care treatment, perioperative mortality remains high in patients with liver cirrhosis undergoing nonhepatic general surgery. In the few existing articles, mortality was reported to be as high as 70% in patients with poor liver function (high Child or model for end-stage liver disease (MELD) score). Since data are limited, we analyzed our recent experience with cirrhotic patients undergoing emergent or elective nonhepatic general surgery at a German university hospital. METHODS: Since 2000, 138 nonhepatic general surgical procedures (99 intra-abdominal, 39 abdominal wall) were performed in patients with liver cirrhosis. Liver cirrhosis was preoperatively classified according to the Child (41 Child A, 59 B, 38 C) and the MELD score (MELD median 13). Sixty-eight (49%) of the patients underwent emergent operations. Most abdominal wall operations were for hernias. Intra-abdominal operations consisted of GI tract procedures (n=53), cholecystectomies (n=15), and various others (n=31). Perioperative data were gained by retrospective analysis. RESULTS: Overall perioperative mortality in all 138 cases was 28% (9% in elective surgery, 47% in emergent surgery; p<0.001). Perioperative mortality was higher after intra-abdominal than after abdominal wall operations (35% vs. 8%; p=0.001) or in patients requiring transfusions (43% vs. 5% without transfusions; p<0.001). Perioperative mortality increased with the Child score (10% Child A, 17% Child B, 63% Child C; p<0.01) and the MELD score (9% MELD <10, 19% MELD 10­15, 54% MELD >15; p<0.001). Univariately, further factors like American Society of Anesthesiologists (ASA) score and various preoperative laboratory values were also associated with perioperative mortality. By multivariate analysis of all 138 operations, the Child and ASA classifications, intraoperative transfusions, and a preoperative sodium <130 mmol/l, but not the MELD score, were independent prognostic factors. Analysis of elective operations revealed only a preoperatively increased creatinine as risk factor for perioperative mortality. In emergent operations again, Child class, blood transfusions, and low sodium level, but not the MELD score, predicted postoperative mortality. CONCLUSIONS: Our results demonstrate that perioperative mortality remains high in patients with liver cirrhosisundergoing general surgery, especially in emergent situations. Patients with poor liver function and/or need for blood transfusions even had a very high mortality. In our experience, the Child score (together with other variables) independently correlates with perioperative mortality in emergent operations whereas the MELD score was inferior in predicting the outcome.

Virus-specific CD4+ T cell responses in chronic HCV infection in blood and liver identified by antigen-specific upregulation of CD154.

BACKGROUND & AIMS: Virus-specific CD4+ T cells play a major role in hepatitis C virus (HCV) infection. Viral clearance is associated with vigorous and multispecific CD4+ T cell responses, while chronic infection has been shown to be associated with weak or absent T cell responses. Most of these studies, however, have used functional assays to analyse virus-specific CD4+ T cell responses. Therefore, the important question, of whether virus-specific CD4+ T cells are completely absent or primarily impaired in specific effector functions during chronic infection, has yet to be analysed in detail. METHODS: To address this issue, a novel assay, where CD4+ T cell frequencies can be determined by de novo CD154 (CD40 ligand) expression in response to HCV antigens, was used in a cohort of chronically infected HCV patients and patients who spontaneously resolved HCV infection. These responses were compared to functional assays, such as the IFN-gamma ELISpot and flow cytometry-based proliferative assays. RESULTS: Our results reveal that using the CD154 assay, virus-specific CD4+ T cells are readily detectable during chronic HCV infection albeit at a lower frequency when compared to patients who spontaneously resolved the infection. Importantly, no CD4+ T cell responses were detectable from these patients when using functional assays. Finally, these cell populations were enriched in the intrahepatic compartment. CONCLUSIONS: Our findings suggest that HCV-specific CD4+ T cell responses are readily detectable in chronic HCV infection and enriched in the infected liver.

Evolving treatments of virus-associated HCC: new targets and drugs.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for HCC development are well defined and some of the multiple steps involved in hepatocarcinogenesis have been elucidated in recent years. The therapeutic options fall into five main categories: (1) surgical interventions, incl. liver transplantation, (2) percutaneous interventions, incl. ethanol injection and radiofrequency thermal ablation, (3) transarterial interventions, (4) radiation therapy and (5) drugs as well as gene and immune therapies. Because of the poor survival of the majority of patients, HCC prevention as well as early diagnosis and the development of novel systemic therapies for advanced disease are of paramount importance. In this context, recent data indicate that the 'targeted therapy' with monoclonal antibodies (mabs) or small molecule tyrosine kinase inhibitors (nibs) and other drugs seem to be effective to some degree. New technologies, including gene expression profiling and proteomic analyses, should allow to further elucidate the molecular events underlying HCC development and to identify novel diagnostic markers as well as therapeutic and preventive targets.

Targeted therapy for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for development of HCC are well defined and some steps of hepatocellular carcinogenesis have been elucidated. Despite these scientific advances and the implementation of measures for early detection of HCC in patients who are at risk of this disease, survival of patients has not improved greatly over the past three decades. This situation is partly due to the limited therapeutic options available. While surgery and percutaneous or transarterial interventions are effective for patients with limited or compensated underlying liver disease, more than 80% of patients present with multifocal HCC and/or advanced liver disease, or have comorbidities at the time of diagnosis. Treatment options for these patients have previously been limited to best supportive care. The effectiveness of targeted therapy with monoclonal antibodies or small-molecule kinase inhibitors has now been demonstrated for the treatment of different tumors. In 2007, the multitargeted kinase inhibitor, sorafenib, was found to prolong survival significantly for patients with advanced HCC. This Review discusses the mechanisms of targeted therapies and clinical studies that have investigated these therapies in patients with HCC. Perspectives for future developments are also provided.

Safety, pharmacokinetics and antiviral effect of BILB 1941, a novel hepatitis C virus RNA polymerase inhibitor, after 5 days oral treatment.

BACKGROUND: BILB 1941 is a potent and specific nonnucleoside inhibitor of the hepatitis C virus (HCV) RNA polymerase in vitro. METHODS: In a double-blind sequential group comparison, 96 male HCV genotype 1 patients with minimal to mild liver fibrosis (Ishak or Metavir score 0-2) were randomized (8 to active treatment and 2 to placebo per dose group) and treated with 10-450 mg BILB 1941 every 8 h over 5 days. Viral load (VL) was measured using Roche Cobas TaqMan assays. RESULTS: VL decreased by > or =1 log10 IU/ml in 2/8, 2/8, 1/8, 2/7, 0/8, 2/8 and 4/5 patients on 60, 80, 100, 150, 200, 300 and 450 mg, respectively. No response was seen with placebo. HCV subtype 1b showed better response than 1a, the effect of other covariables including prior interferon treatment was not significant. NS5B population sequencing and phenotyping identified baseline samples with reduced BILB 1941 susceptibility, but did not detect an on-treatment emergence of resistant mutants. Plasma drug levels were linear until 300 mg. No serious adverse events (AEs) were reported. AEs were mainly gastrointestinal-related (most frequent diarrhoea) and frequency increased with dose. On 450 mg, all five active-treated patients discontinued (four for gastrointestinal intolerance and one for increased aspartate aminotransferase and alanine aminotransferase levels) and the trial was discontinued. CONCLUSIONS: BILB 1941 monotherapy demonstrated antiviral activity against HCV genotype 1, but gastrointestinal intolerance precluded testing of higher doses.

Advances in prevention and diagnosis of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for HCC development are well defined and some of the steps involved in hepatocarcinogenesis have been elucidated in recent years. Despite these advances and the implementation of measures for early HCC detection as well as novel therapeutic strategies, the survival of patients with HCC has not significantly improved until recently. Therefore, early diagnosis and primary, as well as secondary, prevention are of paramount importance in order to reduce morbidity and mortality from HCC. New technologies, including gene expression profiling and proteomic analyses, should allow further elucidation of the molecular events underlying HCC development and identification of novel diagnostic markers as well as therapeutic and preventive targets.

Comprehensive analysis of the alpha-fetoprotein-specific CD8+ T cell responses in patients with hepatocellular carcinoma.

UNLABELLED: Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, with a poor prognosis and limited therapeutic options. Therefore, the development of novel therapeutic strategies is of high priority. alpha-Fetoprotein (AFP) is overexpressed in the majority of HCCs. Priming of immune responses against AFP results in significant protective antitumoral T cell responses in the mouse model. Little information is available about the hierarchy, breadth, frequency, and peripheral versus intrahepatic distribution of AFP-specific CD8(+) T cell responses in patients with HCC. To address these important issues we comprehensively analyzed CD8(+) T cell responses against full-length AFP in peripheral blood, tumor liver tissue, and nontumor liver tissue from patients with HCC using overlapping AFP peptides. The AFP-specific CD8(+) T cell response was also tested in peripheral blood and liver from patients chronically infected with hepatitis C virus (HCV) and compared to the HCV-specific CD8(+) T cell response. The majority of patients with HCC showed AFP-specific responses, with many responses directed against previously unreported epitopes. These responses were primarily detectable in the HCC tissue and mainly targeted the C-terminus of AFP. Interestingly, AFP-specific T cells were not only found in patients with HCC but also in patients with chronic HCV infection, other liver diseases, and less frequently in healthy subjects. CONCLUSION: In patients with HCC, a high frequency of AFP-specific CD8(+) T cells directed against different epitopes suggest that AFP has a strong and broad immunogenicity. Further, CD8(+) T cells specific for the self-antigen AFP are present in the normal T cell repertoire and are not centrally or peripherally deleted. Our results provide support for strategies to boost AFP-specific CD8(+) T cell responses in patients with HCC but also demonstrate a diversity of immune responses that may be needed for protection.

Previously infected chimpanzees are not consistently protected against reinfection or persistent infection after reexposure to the identical hepatitis C virus strain.

Protective immunity after resolved hepatitis C virus (HCV) infection has been reported. However, the breadth of this immunity has remained controversial, and the role of neutralizing antibodies has not been well-defined. In the present study, two chimpanzees (CH96A008 and CH1494) with resolved monoclonal H77C (genotype 1a) infection were rechallenged with low-dose homologous H77C virus about 12 months after viral clearance; CH96A008 became persistently infected, and CH1494 had transient viremia lasting 2 weeks. CH1494 was subsequently either partially or completely protected following five homologous rechallenges with monoclonal H77C or polyclonal H77 and after six heterologous rechallenges with HC-J4 (genotype 1b) or HC-J6 (genotype 2a) viruses. Subsequently, a final challenge with H77C resulted in persistent HCV infection. In both chimpanzees, serum neutralizing antibodies against retroviral pseudoparticles bearing the H77C envelope proteins were not detected during the initial infection or during rechallenge. However, anamnestic cellular immune responses developed during the initial homologous rechallenge, in particular in CH96A008, which developed a persistent infection. Polyprotein sequences of viruses recovered from CH1494 after the two homologous rechallenges that resulted in transient viremia were identical with the H77C virus. In contrast, the polyprotein sequences of viruses recovered from both chimpanzees after homologous rechallenge resulting in persistent infection had numerous changes. These findings have important implications for our understanding of immunity against HCV; even in the best-case scenario with autologous rechallenge, low-level viral persistence was seen in the presence of primed T-cell responses.

Virological and immunological determinants of intrahepatic virus-specific CD8+ T-cell failure in chronic hepatitis C virus infection.

UNLABELLED: Virus-specific CD8+ T-cells play an important role in the outcome of acute hepatitis C virus (HCV) infection. In the chronic phase, however, HCV can persist despite the presence of virus-specific T-cell responses. Therefore, we set out to perform a full-breadth analysis of the intrahepatic virus-specific CD8+ T-cell response, its relation to the peripheral T-cell response, and the overall influence of viral escape and the genetic restriction on intrahepatic CD8+ T-cell failure. Intrahepatic and peripheral CD8+ T-cells from 20 chronically HCV infected patients (genotype 1) were comprehensively analyzed using overlapping peptides spanning the entire HCV polyprotein in concert with autologous viral sequences that were obtained for all targeted regions. HCV-specific CD8+ T-cell responses were detectable in most (90%) chronically HCV-infected patients, and two thirds of these responses targeted novel previously undescribed epitopes. Most of the responses were detectable only in the liver but not in the peripheral blood, indicating accumulation and enrichment at the site of disease. Of note, only approximately half of the responses were associated with viral sequence variations supported by functional analysis as viral escape mutations. Escape mutations were more often associated with HLA-B alleles. CONCLUSION: Our results show an unexpected high frequency of intrahepatic virus-specific CD8+ T-cells, a large part of which continue to target the present viral antigens. Thus, our results suggest that factors other than mutational escape contribute to the failure of intrahepatic virus-specific CD8+ T-cells.

Evolving therapies in the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for HCC development are well defined and some of the steps involved in hepatocarcinogenesis have been elucidated in recent years. Therapeutic options that can be applied in curative or palliative intention are available and are dependent on the HCC stage. The therapeutic options fall into five main categories: (1) surgical interventions, including tumor resection and liver transplantation, (2) percutaneous interventions, including ethanol injection and radiofrequency thermal ablation, (3) transarterial interventions, including embolization and chemoembolization, (4) radiation therapy, and (5) drugs as well as gene and immune therapies. Until recently, no therapy existed for patients with advanced HCC. In 2007 a multikinase inhibitor (sorafenib) showed for the first time a significant increase in overall survival in patients with advanced HCC. Furthermore, several other agents that target different factors of hepatocarcinogenesis (eg, epidermal growth factor, insulin-like growth factors, hepatocyte growth factor, vascular endothelial growth factor, fibroblast growth factor, platelet-derived growth factor, and the transforming growth factors-alpha and -beta), have emerged and been tested in clinical trials. This review gives an overview of the current therapeutic strategies and their clinical impact.

Host and viral factors contributing to CD8+ T cell failure in hepatitis C virus infection.

Virus-specific CD8+ T cells are thought to be the major anti-viral effector cells in hepatitis C virus (HCV) infection. Indeed, viral clearance is associated with vigorous CD8+ T cell responses targeting multiple epitopes. In the chronic phase of infection, HCV-specific CD8+ T cell responses are usually weak, narrowly focused and display often functional defects regarding cytotoxicity, cytokine production, and proliferative capacity. In the last few years, different mechanisms which might contribute to the failure of HCV-specific CD8+ T cells in chronic infection have been identified, including insufficient CD4+ help, deficient CD8+ T cell differentiation, viral escape mutations, suppression by viral factors, inhibitory cytokines, inhibitory ligands, and regulatory T cells. In addition, host genetic factors such as the host's human leukocyte antigen (HLA) background may play an important role in the efficiency of the HCV-specific CD8+ T cell response and thus outcome of infection. The growing understanding of the mechanisms contributing to T cell failure and persistence of HCV infection will contribute to the development of successful immunotherapeutical and -prophylactical strategies.