Acute liver injury following acetaminophen administration does not activate atrophic pathways in the mouse diaphragm.

N-acetyl-para-amino phenol (APAP, usually named paracetamol), which is commonly used for its analgesic and antipyretic properties may lead to hepatotoxicity and acute liver damage in case of overdoses. Released cytokines and oxidative stress following acute liver damage may affect other organs' function notably the diaphragm, which is particularly sensitive to oxidative stress and circulating cytokines. We addressed this issue in a mouse model of acute liver injury induced by administration of APAP. C57BL/6J mice (each n = 8) were treated with N-acetyl-para-amino phenol (APAP) to induce acute drug caused liver injury and sacrificed 12 or 24 h afterwards. An untreated group served as controls. Key markers of inflammation, proteolysis, autophagy and oxidative stress were measured in diaphragm samples. In APAP treated animals, liver damage was proven by the enhanced serum levels of alanine aminotransferase and aspartate aminotransferase. In the diaphragm, besides a significant increase in IL 6 and lipid peroxidation, no changes were observed in key markers of the proteolytic, and autophagy signaling pathways, other inflammatory markers and fiber dimensions. The first 24 h of acute liver damage did not impair diaphragm atrophic pathways although it slightly enhanced IL-6 and lipid peroxidation. Whether longer exposure might affect the diaphragm needs to be addressed in future experiments.

Resolving the fibrotic niche of human liver cirrhosis at single-cell level.

Liver cirrhosis is a major cause of death worldwide and is characterized by extensive fibrosis. There are currently no effective antifibrotic therapies available. To obtain a better understanding of the cellular and molecular mechanisms involved in disease pathogenesis and enable the discovery of therapeutic targets, here we profile the transcriptomes of more than 100,000 single human cells, yielding molecular definitions for non-parenchymal cell types that are found in healthy and cirrhotic human liver. We identify a scar-associated TREM2+CD9+ subpopulation of macrophages, which expands in liver fibrosis, differentiates from circulating monocytes and is pro-fibrogenic. We also define ACKR1+ and PLVAP+ endothelial cells that expand in cirrhosis, are topographically restricted to the fibrotic niche and enhance the transmigration of leucocytes. Multi-lineage modelling of ligand and receptor interactions between the scar-associated macrophages, endothelial cells and PDGFRα+ collagen-producing mesenchymal cells reveals intra-scar activity of several pro-fibrogenic pathways including TNFRSF12A, PDGFR and NOTCH signalling. Our work dissects unanticipated aspects of the cellular and molecular basis of human organ fibrosis at a single-cell level, and provides a conceptual framework for the discovery of rational therapeutic targets in liver cirrhosis.

[Diagnosis and stage-adapted treatment of acute pancreatitis]. / Diagnostik und stadienadaptierte Therapie der akuten Pankreatitis.

Acute pancreatitis is a potentially life-threatening disease, which is morphologically classified into interstitial edematous or necrotizing pancreatitis. According to the revised Atlanta classification, mild, moderate and severe clinical courses are differentiated regarding local and systemic complications as well as concomitant organ failure. In the initial disease phase, the therapeutic measures are focused on (aggressive) volume replacement, early enteral nutrition and adequate analgesia. Characteristic in the course of severe acute pancreatitis are abdominal necroses, which require individualized and interdisciplinary treatment with antibiotic therapy, drainage and definitive necrosectomy. Necrosectomy should be planned as a "step-up approach" using interventional-radiological, endoscopic and minimally invasive surgical procedures.

[Acute liver failure]. / Akutes Leberversagen.

Acute liver failure (ALF) is a rare, but life-threatening disease that is characterized by the acute onset of jaundice, coagulopathy, and hepatic encephalopathy (HE) in patients without pre-existing liver disease. Main causes in Germany are drug toxicity, acetaminophen overdose, and viral hepatitis (A, B, E). For the initial assessment of patients with ALF and the diagnostic algorithm, the early detection of HE, exclusion of liver cirrhosis, immediate diagnosis of the underlying etiology, and evaluation for the necessity of liver transplantation (LT) are critical. Intensive care therapeutic measures aim at preventing or treating complications of ALF. Potentially, plasmapheresis (full plasma exchange) offers a survival benefit for ALF patients who do not undergo LT. The King's College criteria and the Clichy criteria are used as prognostic tools for the indication for LT.

[Acute liver failure]. / Akutes Leberversagen.

Acute liver failure (ALF) is a rare, but life-threatening disease that is characterized by the acute onset of jaundice, coagulopathy, and hepatic encephalopathy (HE) in patients without pre-existing liver disease. Main causes in Germany are drug toxicity, acetaminophen overdose, and viral hepatitis (A, B, E). For the initial assessment of patients with ALF and the diagnostic algorithm, the early detection of HE, exclusion of liver cirrhosis, immediate diagnosis of the underlying etiology, and evaluation for the necessity of liver transplantation (LT) are critical. Intensive care therapeutic measures aim at preventing or treating complications of ALF. Potentially, plasmapheresis (full plasma exchange) offers a survival benefit for ALF patients who do not undergo LT. The King's College criteria and the Clichy criteria are used as prognostic tools for the indication for LT.

CXCR5 is critically involved in progression of lupus through regulation of B cell and double-negative T cell trafficking.

The recruitment of immune cells to sites of tissue inflammation is orchestrated by chemokine/chemokine receptor networks. Among these, the CXCL13/CXCR5 axis is thought to be involved critically in systemic lupus erythematosus (SLE) and lupus nephritis pathogenesis. Beyond B cell abnormalities, another hallmark of SLE disease is the occurrence of aberrant T cell responses. In particular, double-negative (DN) T cells are expanded in the peripheral blood of patients with SLE and in lupus-prone mice. DN T cells induce immunoglobulin production, secrete proinflammatory cytokines and infiltrate inflamed tissue, including kidneys. We aimed to investigate how CXCR5 deficiency changes immune cell trafficking in murine lupus. We therefore crossed CXCR5(-/-) mice with B6/lpr mice, a well-established murine lupus model. B cell numbers and B cellular immune responses were diminished in CXCR5-deficient B6/lpr mice. In addition, we observed reduced accumulation of DN T cells in spleen and lymph nodes, paralleled by reduced splenomegaly and lymphadenopathy. In-vivo migration assays revealed reduced migration of CXCR5-deficient DN T cells into lymph nodes, and ex-vivo-activated CXCR5-deficient DN T cells failed to infiltrate kidneys of recipients. Moreover, DN T cells and B cells of CXCR5-deficient B6/lpr mice failed to migrate towards CXCL13 in vitro. We propose that CXCR5 is involved critically in B cell trafficking and germinal cell (GC) formation in murine lupus and in guiding pathogenic DN T cells into lymphoid organs and kidneys, and we therefore describe new pathomechanisms for the CXCL13/CXCR5 axis in SLE.

Hepatitis delta virus facilitates the selection of hepatitis B virus mutants in vivo and functionally impacts on their replicative capacity in vitro.

To identify molecular interactions between hepatitis B virus (HBV) and hepatitis delta virus (HDV), HBV sequences were analysed in HBV/HDV-infected patients. Characteristic amino acid substitutions were found in cytosolic domains of hepatitis B surface antigen (HBsAg), in contrast to HBV-mono-infected controls. The functional impact of HDV on the replication of wild-type and mutant HBV was assessed in vitro. HDV co-transfection significantly reduced the replication of HBV strains containing precore or basal core promoter mutations, and HBV polymerase or surface antigen mutants affected HDV replication in vitro. Conclusively, our study revealed distinct HBsAg mutational patterns in HBV/HDV-infected patients and novel functional interactions between HBV and HDV.

[First data concerning the medical supply of patients with non-alcoholic fatty liver disease in Germany - a survey in university hospital centers of hepatology]. / Erste Daten zur Versorgungssituation von Patienten mit nicht alkoholischer Fettlebererkrankung (NAFLD) in Deutschland - Eine Umfrage an universitären hepatologischen Zentren.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) currently is one oft the most common reasons for chronic liver injury in the western world. In the European and American population the prevalence is up to 30 %. The medical supply of German patients with NAFLD is variable and has not been analyzed to date. METHODS: We sent questionnaires to all university liver centers in Germany (11 questions) concerning the medical supply of patients with NAFLD. Questions included the rate of patients with fatty liver disease in the outpatient clinics, metabolic comorbidities and the kind of assignment. Besides that, individual clinical standards were documented. We compared longitudinal changes between 2008 and 2013. RESULTS: The return rate of questionnaires was 65 % (n = 20). Analysis showed that the portion of NAFLD patients in the university outpatient clinics had increased between 2008 and 2013 with the predominant part of patients being assigned from external practitioners and not from internal departments of the hospital. Only few patients were assigned by diabetologists or endocrinologists, but on the other hand most liver outpatient clinics investigated their NAFLD patients for metabolic disorders. Cooperation between liver outpatient clinics and other medical services was moderate and was rated average, joint conferences were held rarely. Follow-up visits of patients with NAFLD take place regularly in all centers, however based on different criterions. A consistent algorithm concerning risk assessment and invasive workup does not exist. CONCLUSION: The awareness concerning patients with NAFLD seems to have grown in recent years. Nevertheless, the medical supply of these patients is quite heterogenous and consistent standards do not exist. Therefore, a common guidline is urgently required.

The concanavalin A model of acute hepatitis in mice.

The intravenous injection of the plant lectin concanavalin A (ConA) is a widely used model for acute immune-mediated hepatitis in mice. In contrast to several other models for acute hepatic damage, ConA-induced injury is primarily driven by the activation and recruitment of T cells to the liver. Hence, the ConA model has unique features with respect to its pathogenesis and important similarities to immune-mediated hepatitis in humans, such as autoimmune hepatitis, acute viral hepatitis or distinct entities of drug toxicity leading to immune activation. However, the ConA model has considerable variability, depending on the preparation of the compound, genetic background of the mice, sex, age and microbial environment of the animal facility barrier. This standard operating procedure (SOP) comprises a detailed protocol for the ConA application, including preparation of ConA working solution, handling of the animals, choice of the appropriate conditions and endpoints, as well as efficient dose-finding.

Acetaminophen-induced acute liver injury in mice.

The induction of acute hepatic damage by acetaminophen (N-acetyl-p-aminophenol [APAP]), also termed paracetamol, is one of the most commonly used experimental models of acute liver injury in mice. The specific values of this model are the highly reproducible, dose-dependent hepatotoxicity of APAP and its outstanding translational importance, because acetaminophen overdose is one of the most frequent reasons for acute liver failure (ALF) in humans. However, preparation of concentrated APAP working solutions, application routes, fasting period and variability due to sex, genetic background or barrier environment represent important considerations to be taken into account before implementing this model. This standard operating procedure (SOP) provides a detailed protocol for APAP preparation and application in mice, aimed at facilitating comparability between research groups as well as minimizing animal numbers and distress. The mouse model of acetaminophen poisoning therefore helps to unravel the pathogenesis of APAP-induced toxicity or subsequent immune responses in order to explore new therapeutic interventions for improving the prognosis of ALF in patients.

Induction of experimental obstructive cholestasis in mice.

The induction of experimental obstructive cholestasis is a reliable model for cholestatic liver diseases in rodents. Bile duct ligation (BDL) in mice provokes typical time-dependent morphological and structural changes in the liver, ranging from liver cell injury and elevated serum enzyme levels after several days, to a severe inflammatory response in the liver after 5-7 days, up to an advanced hepatic fibrosis as soon as three to four weeks after surgical ligation of the common biliary duct. Upon BDL induction, hepatic stellate cells become activated and transdifferentiate into myofibroblasts that produce extracellular matrix proteins such as collagen. In principle, the periportal fibrosis induced by BDL in rat livers is reversible. After the relief of a biliary obstruction, the liver has the capacity to revert to a nearly normal histological architecture and a fully normal biochemical function. When BDL surgery is performed by an experienced scientist, this model has very high reproducibility among all fibrotic models. All these factors corroborate the outstanding value of this model for basic and translational research in biomedicine and hepatology. Nevertheless, this model can result in significant variations when surgery is carried out by untrained personnel or when unconscious modifications are implemented that affect the quality of the intervention. A detailed protocol is provided here for the provision of reliable and reproducible BDL in mice.

Comprehensive analysis of mutations in the hepatitis delta virus genome based on full-length sequencing in a nationwide cohort study and evolutionary pattern during disease progression.

Delta hepatitis, caused by co-infection or super-infection of hepatitis D virus (HDV) in hepatitis B virus (HBV) -infected patients, is the most severe form of chronic hepatitis, often progressing to liver cirrhosis and liver failure. Although 15 million individuals are affected worldwide, molecular data on the HDV genome and its proteins, small and large delta antigen (S-/L-HDAg), are limited. We therefore conducted a nationwide study in HBV-HDV-infected patients from Iran and successfully amplified 38 HDV full genomes and 44 L-HDAg sequences from 34 individuals. Phylogenetic analyses of full-length HDV and L-HDAg isolates revealed that all strains clustered with genotype 1 and showed high genotypic distances to HDV genotypes 2 to 8, with a maximal distance to genotype 3. Longitudinal analyses in individual patients indicated a reverse evolutionary trend, especially in L-HDAg amino acid composition, over time. Besides multiple sequence variations in the hypervariable region of HDV, nucleotide substitutions preferentially occurred in the stabilizing P4 domain of the HDV ribozyme. A high rate of single amino acid changes was detected in structural parts of L-HDAg, whereas its post-translational modification sites were highly conserved. Interestingly, several non-synonymous mutations were positively selected that affected immunogenic epitopes of L-HDAg towards CD8 T-cell- and B-cell-driven immune responses. Hence, our comprehensive molecular analysis comprising a nationwide cohort revealed phylogenetic relationships and provided insight into viral evolution within individual hosts. Moreover, preferential areas of frequent mutations in the HDV ribozyme and antigen protein were determined in this study.

[Acute liver failure. Diagnosis and therapy]. / Akutes Leberversagen. Übersicht zur aktuellen Diagnostik und Therapie.

Although acute liver failure is a rare disease with a prevalence of 5 per 1 million people, it has a considerablely high mortality rate of 34 %. The main causes in western civilizations are drug overdose (acetaminophen) and viral hepatitis. Patients are affected by the loss of liver synthesis function and are at risk of developing hepatic encephalopathy and possible multiorgan failure. Specific therapies consisting of the administration of N-acetylcysteine (acetaminophen) or of nucleotide/nucleoside analogs (hepatitis B) are possible, but are often not adequate. Orthotopic liver transplantation is, therefore, frequently the only remaining effective therapy for severe acute liver failure. Due to organ shortage, new prognostic tools, e.g., the Acute Liver Failure Study Group (ALFSG) score, have been developed to improve patient selection using sufficiently stringent selection criteria.

[Abnormal liver function tests in the intensive care unit]. / Leberwerterhöhung auf der Intensivstation.

Abnormal liver biochemical and function tests are found in the majority of critically ill patients and are associated with increased mortality. Frequent causes for elevated liver function tests in the intensive care unit (ICU) are acute hepatic dysfunction due to acute hepatitis, acute liver failure (ALF), and drug-induced liver injury (DILI). Furthermore, exacerbations of pre-existing liver diseases (acute on chronic) and secondary liver injury during critical diseases such as sepsis, right heart failure, or cardiogenic shock, resulting in ischemic or hypoxic hepatitis, need to be considered. Elevated liver enzymes may also reflect a complication of ICU treatment measures like drug-related hepatotoxicity, secondary sclerosing cholangitis in critically ill patients (SC-CIP), or related to parenteral nutrition. Comprehensive diagnostic evaluation is essential to identify the underlying etiology of abnormal liver function tests and to initiate the appropriate therapeutic strategies.

[Management of decompensated liver cirrhosis in the intensive care unit]. / Management der dekompensierten Leberzirrhose auf der Intensivstation.

Liver cirrhosis is the end-stage of long-standing chronic liver diseases. The occurrence of complications from liver cirrhosis increases the mortality risk, but the prognosis can be improved by optimal management in the intensive care unit (ICU). Defined diagnostic algorithms allow the etiology and presence of typical complications upon presentation to the ICU to be identified. Acute variceal bleeding requires endoscopic intervention, vasoactive drugs, antibiotics, supportive intensive care measures and, where necessary, urgent transjugular intrahepatic portosystemic shunt (TIPS) procedure. Spontaneous bacterial peritonitis needs to be diagnosed and immediately treated in patients with ascites. Hepatorenal syndrome should be treated by albumin and terlipressin. In case of respiratory failure, differential diagnosis should not only consider pneumonia, pulmonary embolism and cardiac failure, but also hepatic hydrothorax, portopulmonary hypertension and hepatopulmonary syndrome. The feasibility of liver transplantation should be always discussed in patients with decompensated cirrhosis. Artificial liver support devices may only serve as a bridging procedure until transplant.