Adjusted estimate of the prevalence of hepatitis delta virus in 25 countries and territories

BACKGROUND & AIMS

Hepatitis delta virus (HDV) is a satellite RNA virus that requires the hepatitis B virus (HBV) for assembly and propagation. Individuals infected with HDV progress to advanced liver disease faster than HBV-monoinfected individuals. Recent studies have estimated the global prevalence of anti-HDV antibodies among the HBV-infected population to be 5-15%. This study aimed to better understand HDV prevalence at the population level in 25 countries/territories.

METHODS

We conducted a literature review to determine the prevalence of anti-HDV and HDV RNA in hepatitis B surface antigen (HBsAg)-positive individuals in 25 countries/territories. Virtual meetings were held with experts from each setting to discuss the findings and collect unpublished data. Data were weighted for patient segments and regional heterogeneity to estimate the prevalence in the HBV-infected population. The findings were then combined with The Polaris Observatory HBV data to estimate the anti-HDV and HDV RNA prevalence in each country/territory at the population level.

RESULTS

After adjusting for geographical distribution, disease stage and special populations, the anti-HDV prevalence among the HBsAg+ population changed from the literature estimate in 19 countries. The highest anti-HDV prevalence was 60.1% in Mongolia. Once adjusted for the size of the HBsAg+ population and HDV RNA positivity rate, China had the highest absolute number of HDV RNA+ cases.

CONCLUSIONS

We found substantially lower HDV prevalence than previously reported, as prior meta-analyses primarily focused on studies conducted in groups/regions that have a higher probability of HBV infection: tertiary care centers, specific risk groups or geographical regions. There is large uncertainty in HDV prevalence estimates. The implementation of reflex testing would improve estimates, while also allowing earlier linkage to care for HDV RNA+ individuals. The logistical and economic burden of reflex testing on the health system would be limited, as only HBsAg+ cases would be screened.

IMPACT AND IMPLICATIONS

There is a great deal of uncertainty surrounding the prevalence of hepatitis delta virus among people living with hepatitis B virus at the population level. In this study, we aimed to better understand the burden in 25 countries and territories, to refine techniques that can be used in future analyses. We found a lower prevalence in the majority of places studied than had been previously reported. These data can help inform policy makers on the need to screen people living with hepatitis B virus to find those coinfected with hepatitis delta virus and at high risk of progression, while also highlighting the pitfalls that other researchers have often fallen into.

GLP-2 as an indicator and modulator of acute inflammation improves cardiac function and survival in sepsis

Purpose

GLP-1 and GLP-2 (glucagon-like peptide-1/2) are gut hormones secreted in response to food. While GLP-1 controls glucose metabolism, GLP-2 is a local gut growth factor regulating intestinal nutrient absorption. GLP-2 has been found to be upregulated in patients with colitis. We hypothesize that beyond its local intestinal function GLP-2 might be involved in systemic immune responses.

Methods and results

To analyze whether GLP-2 secretion is modulated by the immune system, we measured circulating GLP-2 levels in 2 clinical cohorts. In the first cohort (n=34) GLP-2 levels increased over time following cardiac surgery as an inflammatory stimulus. In the second cohort 223 patients with sepsis had a 3.9 fold increase of GLP-2 plasma levels vs. 53 healthy controls (3.0 ng/mL vs. 11.4 ng/mL; p<0.001). High GLP-2 levels were associated with markers of inflammation (IL-6, PCT, CRP), septic cardiomyopathy (NT-proBNP) and independently predicted mortality in humans with sepsis. Induction of sepsis in mice by endotoxin or cecal ligation puncture strongly increased GLP-2 levels independent from food intake. By injecting various proinflammatory cytokines and inducing sepsis in IL1R−/− and IL6−/− mice we identified that inflammation upregulates GLP-2 secretion through IL-6. To identify the source of GLP-2 secretion under inflammation, we induced sepsis in Gcg−/− mice lacking endogenous GLP-2 production with a tissue-specific reactivation of Gcg in gut L-cells (GcgRAΔvilCre) or pancretic alpha cells (GcgRAΔPDX1-Cre). We observed sepsis-induced GLP-2 secretion to be derived from the pancreas and not from the gut. Additional in-vitro and ex-vivo approaches revealed that IL-6 directly activates GLP-2 secretion from pancreatic alpha cells. Gcg−/− mice lacking GLP-2 production and Glp2r−/− mice show aggravated sepsis indicating that endogenous upregulation of GLP-2 is protective. Finally, we analyzed whether inflammatory upregulation of GLP-2 has immunomodulatory relevance. We administered GLP-2 or saline as control per central jugular vein catheter mice who underwent CLP. GLP-2 treatment improved LV-contractility (dp/dtmax) in septic cardiomyopathy (control 7361 vs. GLP-2 9500 mmHg/s; p<0.01), inhibited sepsis-induced hypotension and reduced mortality (p=0.018). Mechanistically GLP-2 reduced myeloid immune cell infiltration into heart and liver tissue and decreased proinflammatory cytokine levels in various organs and the blood (TNF-α, IL-6 and IL-1β). After broad GLP-2 receptor profiling we found maximum mRNA expression in gut tissues with no expression on immune cells. By further mechanistic studies we found GLP-2 to protect against sepsis-induced gut barrier dysfunction.

Conclusions

Here we identified a counter-regulatory control system in which IL-6 derived upregulation of GLP-2 secretion limits excessive innate immune responses and protects against sepsis. These findings might open new avenues for the treatment of patients with inflammatory diseases.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): European Foundation for the Study of Diabetes, European Research Area Network on Cardiovascular Diseases (ERA-CVD and BMBF), Deutsche Forschungsgemeinschaft (DFG)

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

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]

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]

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]

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.

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.

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.

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]

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.

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.

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]

Das akute Leberversagen (ALV) ist mit einer Prävalenz von 5 pro 1 Mio. Einwohner zwar selten, besitzt aber eine sehr hohe Mortalitätsrate von etwa 34 %. Es wird in westlichen Zivilisationen hauptsächlich durch Medikamente (Paracetamol) und virale Hepatitiden ausgelöst. Die Patienten sind hauptsächlich durch den Ausfall der Lebersynthesefunktion, die Entwicklung einer hepatischen Enzephalopathie und ein mögliches Multiorganversagen gefährdet. Spezifische Therapien sind mit der Gabe von N-Acetylcystein (Paracetamol) oder von Nukleotid-/Nukleosid-Analoga (Hepatitis-B) zwar möglich, oft aber nicht ausreichend effektiv. Die Durchführung einer Lebertransplantation ist hier oft die einzige verbleibende Therapieoption. Neue Prognosescores, wie der Acute-liver-failure-study-group(ALFSG)-Score, ermöglichen eine verbesserte Patientenselektion, um dem Organmangel durch eine ausreichend stringente Indikationsstellung gerecht zu werden.

Soluble urokinase plasminogen activator receptor is compartmentally regulated in decompensated cirrhosis and indicates immune activation and short-term mortality

OBJECTIVE

Patients with decompensated cirrhosis are susceptible to bacterial infections, which are associated with organ failure and a high mortality rate. Reliable biomarkers are needed to identify patients who require intensified treatment. Our objective was to study the regulation and prognostic relevance of elevated concentrations of soluble urokinase plasminogen activator receptor (suPAR) in patients with advanced cirrhosis.

DESIGN, SETTING AND PARTICIPANTS

We examined the associations between serum and ascitic fluid (AF) suPAR and liver function, bacterial infection, and short-term mortality in 162 consecutive patients with decompensated cirrhosis undergoing diagnostic paracentesis in a tertiary health care centre in Germany.

MAIN OUTCOME MEASURE

Twenty-eight-day mortality.

RESULTS

Circulating suPAR levels were increased in patients with decompensated cirrhosis and correlated with the severity of liver dysfunction and systemic inflammation but were not indicative of bacterial infection. Circulating suPAR levels >14.4 ng mL(-1) predicted 28-day mortality, even after adjustment for liver function and confounders [HR = 3.05 (1.35-6.90); P = 0.0076] equal to the MELD score (AUC = 0.71; 95% CI = 0.61-0.81; P < 0.001). Cut-off levels derived from cohorts without liver disease were not applicable due to the low specificity. AF suPAR levels were elevated during spontaneous bacterial peritonitis (SBP), but not during episodes in which bacteria or bacterial DNA was translocated into the ascites. AF suPAR levels correlated poorly with systemic suPAR but were associated with a more severe course of SBP and a worse outcome. In vitro experiments revealed that monocytes, and to a lesser extent neutrophils, secrete suPAR after Toll-like-receptor ligation, which led to rapid urokinase plasminogen activator receptor cleavage followed by increased synthesis.

CONCLUSION

Blood and ascitic suPAR levels provide distinct, but relevant prognostic information on the severity of complications in patients with end-stage liver disease.

Hepatitis B e antigen-suppressing mutations enhance the replication efficiency of adefovir-resistant hepatitis B virus strains

Hepatitis B e antigen (HBeAg) negative hepatitis B virus (HBV) infections caused by precore (PC) or basal core promoter (BCP) mutations are associated with disease progression and complications. PC or BCP mutations may enhance the replication capacity of distinct drug-resistance-associated polymerase mutations, but their effect on adefovir-resistant HBV mutants is unclear. Importantly, BCP mutations were an independent risk factor for virological breakthrough in lamivudine-resistant patients treated with adefovir. We aimed at addressing the functional consequences of PC and BCP mutations on the replication and drug susceptibility of adefovir-resistant HBV mutants. Therefore, HBV constructs with wild type (WT) or adefovir-resistant rtN236T, rtA181V and rtA181T mutations, with or without concomitant PC or BCP mutations, were analysed in vitro using molecular assays. The adefovir-resistant polymerase mutations rtN236T, rtA181V and rtA181T showed a drastically reduced viral replication compared with WT. Interestingly, additional PC or BCP mutations enhanced the reduced replication efficacy of adefovir-resistant constructs and restored HBV replication to WT level. HBV rtA181T mutants displayed abolished hepatitis B surface antigen (HBsAg) secretion, owing to a sW172* stop codon in the overlapping envelope gene. All rtN236T- or rtA181V/T-containing constructs, regardless of concomitant PC or BCP mutations, were resistant to adefovir, but remained susceptible to telbivudine, entecavir and tenofovir. In conclusion, adefovir drug resistance mutations reduced viral replication, which can be significantly increased by additional HBeAg-suppressing PC or BCP mutations. Because increased HBV replication in HBeAg-negative patients has been associated with an unfavourable clinical course, close monitoring appears indispensable during adefovir treatment in HBeAg-negative patients.

[Gastrointestinal bleeding in liver cirrhosis at the ICU]

Due to portal hypertension and bleeding disorders, patients with liver cirrhosis are at increased risk for severe gastrointestinal bleedings (GIB), commonly requiring therapy at the intensive care unit (ICU). In order to identify epidemiological and prognostic factors for GIB in cirrhotic patients, we retrospectively analysed patients from our medical ICU from 1999 to 2010. Among 7376 critically ill patients, 650 (8.8 %) were diagnosed with liver cirrhosis. Hepatic cirrhosis was frequently found in ICU patients admitted due to severe GIB (23.2 % of 711 patients had cirrhosis). Moreover, patients with cirrhosis were at increased risk to develop severe GIB during intensive care treatment (40.9 % of 44 patients with GIB during ICU stay had cirrhosis). Besides the high rate of variceal bleedings (64.4 %) in cirrhotic patients, non-variceal haemorrhages were also common (28.5 %). We identified the MELD score and necessity of mechanical ventilation as independent risk factors for mortality in cirrhotic patients with severe GIB. Patients with liver cirrhosis and severe GIB had significantly impaired prognosis (case-related fatality rate of 26.1 % with cirrhosis vs. 6.8 % without cirrhosis), especially in cases of newly developed GIB during ICU therapy. Advanced therapeutic approaches and novel strategies are warranted to improve the critical prognosis of these high-risk patients.

Endoscopic ultrasound as an early diagnostic tool for primary sclerosing cholangitis: a prospective pilot study

BACKGROUND AND STUDY AIMS

Primary sclerosing cholangitis (PSC) is a rare, chronic cholestatic liver disease, which typically affects middle-aged men and is frequently associated with inflammatory bowel disease. Early recognition and accurate diagnosis remains a clinical challenge. Invasive diagnostic procedures, such as endoscopic retrograde cholangiography or liver biopsy are needed when magnetic resonance cholangiopancreatography remains inconclusive. As these procedures are associated with significant risks, the current study sought to determine whether endoscopic ultrasound (EUS) of the biliary tract is a useful diagnostic tool in cases of suspected PSC.

PATIENTS AND METHODS

In a prospective pilot study, 138 patients presenting with chronic cholestatic hepatopathy were screened and 32 patients with possible PSC were evaluated further. In addition to all routine measures, EUS was included in the diagnostic work-up.  The following parameters were evaluated and compared with the definitive diagnosis: wall thickening ( ≥ 1.5  mm), irregular wall structure, significant changes of caliber of the common bile duct, and perihilar lymphadenopathy.

RESULTS

In the 138 patients screened, a PSC prevalence of 13 % was found. Of the 32 patients included in the study, 17 had large-duct PSC diagnosed. When two of the aforementioned four parameters showed PSC-like features, sensitivity and specificity of predicting PSC were 76.4 % and 100 %, with positive and negative predictive values of 100 % and 79 %, respectively. In four patients presenting with strictly intrahepatic disease, EUS was not diagnostic.

CONCLUSIONS

EUS proved to be a valuable tool in suspected PSC and accurately predicted extrahepatic disease. EUS should be evaluated further as an early procedure in routine diagnostic measurements. This approach promises a significant improvement in disease detection as well as a reduction in high risk invasive procedures.

Monocytes in health and disease - Minireview

Monocytes are important cell types of the innate immune system. Recent scientific evidence suggests that monocytes not only play a crucial role in our innate immune system by defending the host from intruding microbial pathogens but they also contribute to the pathogenesis and progression of diseases such as liver fibrosis, atherosclerosis, multiple sclerosis, and tumor metastasis. In addition, monocytes and monocyte-derived macrophages play a crucial beneficial role in the liver fibrosis regression, muscle regeneration, and the clearance of the β-amyloid plaques in Alzheimer's disease. Here, we summarize the origin, plasticity, and pathogenic potential of monocytes and monocyte-derived macrophages, as well as their positive role in the regression of some common diseases. Elucidating the comprehensive immunological role of monocytes will provide therapeutic advantages in either controlling disease progression or favoring the regression of the disease state.

[Treatment of inflammatory bowel disease in intensive care medicine]

In patients with inflammatory bowel disease (IBD) complications of both IBD and immunosuppressive therapy may be life-threatening conditions requiring intensive care therapy. These patients oftentimes present themselves with severe bloody diarrhoea, and infectious colitis, pseudomembranous colitis or intestinal ischemia must be included in the differential diagnosis. Steroids, immunosuppressants such as azathioprine, 6-mercaptopurine, methotraxate or ciclosporine, as well as biologicals, which act as TNF-alpha antagonists, are commonly used for maintenance therapy and treatment of acute exacerbations of IBD. Due to immunosuppressive therapy potentially life-threatening infections and reactivations of latent infections like tuberculosis or cytomegalovirus (CMV) can occur. Fistulas, abscesses, perforations and intestinal obstructions are typical complications of Crohn's disease in the intensive care setting, whereas clinical presentation in ulcerative colitis is characterised by its acute exacerbation and the toxic dilatation of the colon, potentially resulting in toxic megacolon with high risk of perforation or severe bleeding. Most important for an effective therapy in the critically ill patient with inflammatory bowel disease are the control of the underlying disease, the empiric antibiotic therapy in case of infectious complications, transcutaneous drainage of abscesses, bowel decompression in toxic megacolon and the early interdisciplinary assessment of the abdomen.

Impact of hepatitis B e antigen-suppressing mutations on the replication efficiency of entecavir-resistant hepatitis B virus strains

Hepatitis B e antigen (HBeAg)-negative hepatitis B commonly requires long-term treatment with nucleos(t)ide analogues aiming at persistently suppressing hepatitis B virus (HBV) replication to halt progression of liver disease and prevent complications. Entecavir (ETV) is widely used in HBeAg-negative hepatitis B, but distinct HBV polymerase mutations can confer resistance against ETV, in conjunction with lamivudine resistance. Precore (PC) and basal core promoter (BCP) mutations that underlie HBeAg-negativity enhance replication of lamivudine-resistant mutants. To comprehensively analyse the impact of PC or BCP mutations on viral replication of ETV-resistant HBV mutants, replication-competent HBV constructs were generated harbouring lamivudine resistance (rtM204V/rtL180M, rtM204I) plus ETV resistance (rtS202G, rtS202I or rtT184G) on wild-type (WT)-, PC- and BCP-backgrounds. Functional consequences on viral fitness and susceptibility to antivirals were assessed in vitro. The presence of any ETV resistance drastically reduced viral replication when compared to WT HBV. In rtS202G mutants (plus lamivudine resistance), addition of either PC or BCP mutations moderately enhanced the reduced replication, without reaching WT HBV levels. In rtS202I or rtT184G mutants, PC and BCP mutations did not significantly improve viral fitness. All ETV-resistant constructs, independently of PC or BCP mutations, showed resistance towards ETV and lamivudine, but remained susceptible to tenofovir. Our data demonstrate that HBeAg-suppressing PC or BCP mutations cannot restore the strongly reduced replicative capacity of ETV-resistant HBV mutants to WT level, although they moderately increase replication of rtS202G combination mutants. ETV resistance thereby differs from lamivudine resistance alone, corroborating that ETV is in short term a safe option for HBeAg-negative patients.

Single-step real-time PCR to quantify hepatitis B virus and distinguish genotype D from non-D genotypes

Hepatitis B virus (HBV) viral load and its genotype play important roles in clinical outcome, management of disease and response to antiviral therapy. In many parts of the world such as Europe or the Middle East, distinguishing HBV genotype D from non-D is most relevant for treatment decisions, because genotype D-infected patients respond poorly to interferon-based therapeutic regimens. Here, we developed an in-house real-time PCR to concordantly assess HBV genotype (D vs non-D) based on melt curve analysis and quantify the viral load. Genotype distinction was established with control plasmids of all HBV genotypes and validated with 57 clinical samples from patients infected with six different HBV genotypes. Our in-house real-time PCR assay could discriminate HBV genotype D from non-D using single-step melt curve analysis with a 2 °C difference in the melt curve temperature in all samples tested. Viral load quantification was calibrated with the WHO HBV international standard, demonstrating an excellent correlation with a commercial kit (r = 0.852; P < 0.0001) in a linear range from 3.2 × 10(2) to 3.2 × 10(10) IU/mL. In conclusion, we developed a rapid, simple and cost-effective method to simultaneously quantify and distinguish HBV genotypes D from non-D with a single-step PCR run and melt curve analysis. This assay should be a useful diagnostic alternative to aid clinical decisions about initiation and choice of antiviral therapy, especially in geographical regions with a high prevalence of HBV genotype D.

[Liver fibrosis - pathogenesis and novel therapeutic approaches]

Chronic liver injury, such as viral hepatitis, alcohol, metabolic syndrome or other toxic damages, leads to an inflammatory response including the infiltration and activation of immune cells and to the proliferation and transdifferentiation of mesenchymal cells within the liver, especially of hepatic stellate cells. These cells produce an excess of extracellular matrix proteins that are deposited in the liver. Hepatic fibrosis may progress to liver cirrhosis and liver failure. This review aims at summarizing the current view on the pathogenic sequence during fibrogenesis highlighting the essential role of cytokines and chemokines. Understanding the complex cellular interactions in liver fibrosis may help to develop novel antifibrotic therapies in the near future.

[ALT screening for chronic liver diseases: scrutinizing the evidence]

Elevated serum amino-transferase levels may be associated with liver injury. Testing for aspartate aminotransferase (AST) or alanine aminotransferase (ALT) is part of many routine screening approaches. The aim of this manuscript was to scrutinize the evidence for using ALT testing as a primary screening parameter for liver diseases. We conclude that (i) elevated serum ALT levels indicate a high specificity and a reasonable sensitivity liver injury, (ii) 10 - 25 % of German adults have elevated ALT levels, (iii) ALT values are increased in the majority but not all patients with acute and chronic liver disease (iv) elevated ALT-values are associated with an increased risk of liver-specific mortality, (v) elevated ALT values are also a risk factor for non-hepatic diseases including diabetes mellitus type 2, metabolic syndrome, cardiovascular diseases and malignancies, (vi) many liver diseases identified by an ALT screening can be treated successfully including prevention of development of clinical endpoints, (vii) an ALT-screening is very likely to be cost-effective although studies are needed for Germany to support this conclusion.

[ALT screening for chronic liver diseases: scrutinizing the evidence]

Elevated serum amino-transferase levels may be associated with liver injury. Testing for aspartate aminotransferase (AST) or alanine aminotransferase (ALT) is part of many routine screening approaches. The aim of this manuscript was to scrutinize the evidence for using ALT testing as a primary screening parameter for liver diseases. We conclude that (i) elevated serum ALT levels indicate a high specificity and a reasonable sensitivity liver injury, (ii) 10 - 25 % of German adults have elevated ALT levels, (iii) ALT values are increased in the majority but not all patients with acute and chronic liver disease (iv) elevated ALT-values are associated with an increased risk of liver-specific mortality, (v) elevated ALT values are also a risk factor for non-hepatic diseases including diabetes mellitus type 2, metabolic syndrome, cardiovascular diseases and malignancies, (vi) many liver diseases identified by an ALT screening can be treated successfully including prevention of development of clinical endpoints, (vii) an ALT-screening is very likely to be cost-effective although studies are needed for Germany to support this conclusion.

Value of magnifying endoscopy in classifying colorectal polyps based on vascular pattern

BACKGROUND AND STUDY AIMS

Narrow-band imaging (NBI) has been developed as a new technique to differentiate tissue patterns in vivo. The aim of this study was to evaluate the diagnostic accuracy of NBI endoscopy with and without high magnification for the differentiation of neoplastic from non-neoplastic colorectal polyps.

PATIENTS AND METHODS

Among 200 colorectal polyps from 131 patients, 100 lesions were classified according to vascular patterns by NBI endoscopy with high optical magnification and 100 lesions by high-definition endoscopy without high magnification. Additionally, the clarity of the vessel network was assessed. Histologic analysis was performed on all lesions.

RESULTS

NBI endoscopy with high magnification resulted in a sensitivity of 92.1 % and a specificity of 89.2 % for the differentiation of neoplastic versus non-neoplastic lesions. This performance was statistically comparable to high-definition NBI endoscopy without high magnification, which showed a sensitivity of 87.9 % and specificity of 90.5 %. However, vessel network was significantly better visualized by NBI endoscopy with optical magnification compared with high-definition NBI endoscopy without high magnification. In comparison with NBI endoscopy, white-light endoscopy, with or without magnification, resulted in inferior discrimination between neoplastic and non-neoplastic polyps.

CONCLUSION

The results demonstrate that the superior visibility of capillary vessels by the NBI technique allows the evaluation of colorectal lesions - based on the vascular patterns - with high diagnostic accuracy. In clinical routine, high-definition NBI endoscopy without high magnification may be used to sufficiently predict colorectal polyp histology, and high magnification can additionally facilitate visualization of vascular networks.

Validation of connective tissue growth factor (CTGF/CCN2) and its gene polymorphisms as noninvasive biomarkers for the assessment of liver fibrosis

Clinical and experimental studies have demonstrated that connective-tissue growth factor (CTGF) expression is increased in fibrotic human liver and experimental animal models of liver fibrogenesis. CTGF has been linked to transforming growth factor-beta (TGF-beta) pathways in fibroproliferative diseases and specific polymorphisms within the CTGF gene may predispose for fibrosis in systemic sclerosis. As CTGF is detectable in various human fluids (serum, plasma and urine), it may provide information about fibrotic remodelling processes and reflect hepatic TGF-beta bioactivity. We established a novel ELISA for the measurement of serum CTGF and tested its clinical value in patients with chronic hepatitis C virus (HCV) infection and chronic liver disease (CLD). HCV infected patients (n = 138) had significantly higher serum CTGF levels than healthy controls. CTGF was linked to the histological degree of liver fibrosis. To expand the results to other aetiologies, a separate cohort of CLD patients (n = 129) was evaluated, showing higher serum CTGF than healthy controls and again an association with advanced stages of liver cirrhosis (Child B and C). Although independent of the underlying aetiology, serum CTGF was most powerful in indicating fibrosis/advanced disease states in HCV-related disorders. The genotyping of six polymorphisms (rs6917644, rs9399005, rs6918698, rs9493150, rs2151532 and rs11966728) covering the CTGF locus in 365 patients suffering from chronic hepatitis C revealed that none of these polymorphisms showed a genotypic or allelic association with the severity of hepatic fibrosis. Taken together, serum CTGF is suitable for determination of hepatic fibrosis and most powerful in patients with chronic HCV infection.

Elevated apoptosis-associated cytokeratin 18 fragments (CK18Asp386) in serum of patients with chronic liver diseases indicate hepatic and biliary inflammation

OBJECTIVES

During apoptosis, intermediate filament protein cytokeratin 18 (CK18) is cleaved by caspases at Asp396 which can be specifically detected by the monoclonal antibody M30 (M30-antigen).

DESIGN AND METHODS

M30-antigen serum levels were analyzed in 76 chronic liver diseases (CLD) patients and 62 healthy controls.

RESULTS

M30-antigen levels were significantly elevated in CLD patients (median 296.3 U/L) compared with healthy controls (median 153.5 U/L, P<0.001) and increased with disease severity (Child-Pugh or MELD score). M30-antigen correlated with aminotransferase activities and parameters indicating cholestasis such as bile acids. Highest serum M30-antigen was associated with histologically confirmed severe intrahepatic cholestasis (median 599.1 U/L) or biliary duct inflammation (median 648.0 U/L). Furthermore, in contrast to patients with liver cirrhosis, presence of hepatocellular carcinoma was associated with elevated M30-antigen in patients without cirrhosis.

CONCLUSION

Serum M30-antigen levels are elevated in CLD and correlate with hepatic inflammation as well as cholangitis and cholestasis.

CREB/PKA sensitive signalling pathways activate and maintain expression levels of the hepatitis B virus pre-S2/S promoter

BACKGROUND AND AIMS

CREB (cAMP response element binding protein) transcription factors are key regulators of homeostatic functions in the liver, and CRE binding is increased in hepatic inflammation. During chronic hepatitis B virus (HBV) infection, mutations or deletions in the pre-S region are frequently observed. These mutations can affect the pre-S2/S promoter controlling HBV envelope protein expression (hepatitis B surface antigen (HBsAg)) and have been associated with worsened clinical outcome. We aimed to test if CREB activation impacts on HBsAg expression.

METHODS

The effect of the CREB inducer protein kinase A (PKA) was tested by coexpression with HBV wild-type vector in vitro. Luciferase reporter gene constructs were cloned to identify novel regulatory regions for the HBV pre-S2/S promoter. Electrophoretic mobility shift assay (EMSA) gelshift and supershift experiments were conducted to confirm DNA transcription factor binding.

RESULTS

Coexpression of HBV and PKA resulted in HBV-S mRNA induction and enhanced small envelope protein expression. We identified a CREB binding motif in the transcribed part of the pre-S2 region, contributing to basal S promoter activity via binding of activating transcription factor 2 (ATF2). A second CREB motif closely linked to the S-ATG showed a similar binding pattern involving ATF2 and CREB1, without appearing essential for basal promoter activity. Moreover, a sequence in the pre-S2 region is responsible for further transcriptional induction via CREB activators such as PKA and forskolin. EMSA experiments indicate that CREB1 and ATF4 are involved in complex formation conferring PKA dependent promoter activation.

CONCLUSIONS

Our data suggest a novel mechanism by which HBV may utilise CREB/PKA signal transduction pathways of hepatocytes to enhance its HBsAg expression during homeostasis and hepatic inflammation.

Yersinia infection mimicking recurrence of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. So far, surgical resection has been the only curative treatment, but new options became available with the application of imatinib (Glivec) as a specific molecular inhibitor. Even after complete resection, GISTs have a high rate of recurrence and disease-linked mortality. Here we report on the case of a clinically well 57-year-old woman who presented to us 3 years after resection of a GIST of the small intestine. Abdominal ultrasound and CT scan showed intestinal wall thickening in the area of anastomosis and mesenteric lymphadenopathy, suggesting a recurrence of the primary GIST. However, serological testing was positive for yersinia antibodies. Surgical exploration revealed an asymptomatic infection with Yersinia enterocolitica serotype O9, proven by positive culture and histology, which showed no evidence of malignancy. Prognostic variables for GIST as well as diagnostic measures and limitations for yersiniosis are discussed. In the end, only surgical exploration and histological analysis could establish the final diagnosis. In conclusion, GISTs have a high likelihood of recurrence even after complete resection, but an asymptomatic infection such as yersiniosis must be considered as a differential diagnosis to GIST recurrence.

Analysis of factors contributing to higher erythropoietin levels in patients with chronic liver disease

BACKGROUND

Dysregulated erythropoietin (EPO) plasma levels may play a role in the pathophysiology of chronic liver disease (CLD) because chronic anaemia is frequently observed in patients with liver cirrhosis. We aimed to identify the factors contributing to EPO regulation in patients with CLD.

METHODS

Plasma EPO concentrations were correlated with clinical and laboratory parameters in 111 CLD patients and 220 healthy controls.

RESULTS

Anaemia, though generally mild, was common in CLD patients, and thrombocytopenia and previous bleeding episodes were observed in two-thirds of the patients. Plasma EPO levels were significantly elevated in CLD patients (P < 0.001). EPO increased according to Child's stages of cirrhosis, independently of the aetiology of CLD. EPO correlated with haemoglobin (r= -0.498, P < 0.001). Additionally, EPO independently correlated with markers of liver dysfunction, e.g. prothrombin time, albumin concentration or cholinesterase activity, and platelet count. EPO was also significantly elevated in patients with a current bleeding tendency and with prior gastrointestinal haemorrhages. EPO levels were increased in patients with impaired pulmonary function, e.g. decreased diffusion capacity, vital capacity or hyperventilation. Interestingly, plasma interleukin-6 (IL-6) concentrations positively correlated with EPO (r=0.277, P = 0.003), suggesting a possible mechanism of EPO upregulation in patients with CLD through IL-6 dependent pathways, e.g. binding of STAT transcription factors in the putative EPO promoter region.

CONCLUSIONS

EPO is upregulated in patients with chronic liver diseases in response to anaemia, bleeding complications, impaired pulmonary function, thrombocytopenia and liver dysfunction. IL-6 dependent pathways could be involved in mediating elevated EPO levels in CLD patients.

Tissue factor and thrombomodulin levels are correlated with stage of cirrhosis in patients with liver disease

Liver cirrhosis is associated with alterations of the coagulation system commonly causing bleeding as well as thromboembolic complications. The potential pathophysiological roles of tissue factor (TF) (the initiator of the extrinsic coagulation pathway) and thrombomodulin (TM) (an initiator of the anticoagulatory protein C pathway) are unknown. We therefore measured plasma concentrations of TF and TM in 111 patients with liver diseases who were evaluated for liver transplantation. We could demonstrate that the levels of both molecules increased with the Child's class of liver cirrhosis, independently of aetiology. TM was significantly elevated in Child A, B and C patients compared with patients without cirrhosis; TF only in Child C patients. The plasma TM and TF concentrations correlated with prothrombin time, activated partial thromboplastin time, and inversely with factor VII activity, cholinesterase serum activity, and serum albumin concentration. TM was elevated in patients with a bleeding tendency, but TM and TF did not differ between patients with or without prior thrombotic events. Further studies are warranted to clarify the underlying mechanisms that raise TM and TF plasma levels in liver disease with possible clinical consequences.

Endogenous serum levels of thrombopoietic cytokines in healthy whole-blood and platelet donors: implications for plateletpheresis

Serum concentrations of the thrombopoiesis-enhancing cytokines thrombopoietin (TPO), erythropoietin (EPO), interleukin (IL)-6 and IL-11 were determined in 119 healthy whole-blood (WBD) and 101 platelet donors (PD) prior to donation. The 90% TPO reference interval in WBD of 64-867 pg/ml (median 163, 100% range 45-7572) was significantly higher than in PD of 56-524 (median 122, range 44-801, P = 0.004), whereas their platelet counts were lower (P < 0.001). EPO levels were not different (WBD 7.7 +/- 3.8, PD 8.0 +/- 4.9 IU/l), IL-6 and IL-11 were below the detection limit in >/=90% of cases (IL-6 < 3.2 pg/ml, IL-11 < 31.2 pg/ml). None of the cytokines correlated with platelet counts, other blood parameters, or in the PD group with the frequency of platelet donations within the last 6 months. We conclude that plateletpheresis does not lead to a lasting increase of thrombopoietic cytokines and provide reference data for potential platelet mobilization strategies with recombinant growth factors.