Search

Interleukin-7 (IL-7) is an important cytokine with pivotal pro-survival functions in the adaptive immune system. However, the role of IL-7 in innate immunity is not fully understood. In the present study, the impact of hepatic IL-7 on innate immune cells was assessed by functional experiments as well as in patients with different stages of liver cirrhosis or acute-on-chronic liver failure (ACLF). Human hepatocytes and liver sinusoidal endothelial cells secreted IL-7 in response to stimulation with interferons (IFNs) of type I and II, yet not type III. De novo translation of interferon-response factor-1 (IRF-1) restricted IL-7 production to stimulation with type I and II IFNs. LPS-primed human macrophages were identified as innate immune target cells responding to IL-7 signaling by inactivation of Glycogen synthase kinase-3 (GSK3). IL-7-mediated GSK3 inactivation augmented LPS-induced secretion of pro-inflammatory cytokines and blunted LPS tolerance of macrophages. The IFN-IRF-1-IL-7 axis was present in liver cirrhosis patients. However, liver cirrhosis patients with or without ACLF had significantly lower concentrations of IL-7 in serum compared to healthy controls, which might contribute to LPS-tolerance in these patients. In conclusion, we propose the presence of an inflammatory cascade where IFNs of type I/II induce hepatocellular IL-7 in an IRF-1-restriced way. Beyond its role in adaptive immune responses, IL-7 appears to augment the response of macrophages to LPS and to ameliorate LPS tolerance, which may improve innate immune responses against invading pathogens.

Alcoholism is one of the leading and increasingly prevalent reasons of liver associated morbidity and mortality worldwide. Alcoholic hepatitis (AH) constitutes a severe disease with currently no satisfying treatment options. Lipoxin A4 (LXA4), a 15-lipoxygenase (ALOX15)-dependent lipid mediator involved in resolution of inflammation, showed promising pre-clinical results in the therapy of several inflammatory diseases. Since inflammation is a main driver of disease progression in alcoholic hepatitis, we investigated the impact of endogenous ALOX15-dependent lipid mediators and exogenously applied LXA4 on AH development. A mouse model for alcoholic steatohepatitis (NIAAA model) was tested in Alox12/15+/+ and Alox12/15-/- mice, with or without supplementation of LXA4. Absence of Alox12/15 aggravated parameters of liver disease, increased hepatic immune cell infiltration in AH, and elevated systemic neutrophils as a marker for systemic inflammation. Interestingly, i.p. injections of LXA4 significantly lowered transaminase levels only in Alox12/15-/- mice and reduced hepatic immune cell infiltration as well as systemic inflammatory cytokine expression in both genotypes, even though steatosis progressed. Thus, while LXA4 injection attenuated selected parameters of disease progression in Alox12/15-/- mice, its beneficial impact on immunity was also apparent in Alox12/15+/+ mice. In conclusion, pro-resolving lipid mediators may be beneficial to reduce inflammation in alcoholic hepatitis.

Introduction: Quinolone prophylaxis is recommended for patients with advanced cirrhosis at high risk of spontaneous bacterial peritonitis (SBP) or with prior SBP. Yet, the impact of long-term antibiotic prophylaxis on the microbiome of these patients is poorly characterized. Methods: Patients with liver cirrhosis receiving long-term quinolone prophylaxis to prevent SBP were prospectively included and sputum and stool samples were obtained at baseline, 1, 4 and 12 weeks thereafter. Both bacterial DNA and RNA were assessed with 16S rRNA sequencing. Relative abundance, alpha and beta diversity were calculated and correlated with clinical outcome. Results: Overall, 35 stool and 19 sputum samples were obtained from 11 patients. Two patients died (day 9 and 12) all others were followed for 180 days. Reduction of Shannon diversity and bacterial richness was insignificant after initiation of quinolone prophylaxis (p > 0.05). Gut microbiota were significantly different between patients (p < 0.001) but non-significantly altered between the different time points before and after initiation of antibiotic prophylaxis (p > 0.05). A high relative abundance of Enterobacteriaceae > 20% during quinolone prophylaxis was found in three patients. Specific clinical scenarios (development of secondary infections during antibiotic prophylaxis or the detection of multidrug-resistant Enterobacteriaceae) characterized these patients. Sputum microbiota were not significantly altered in individuals during prophylaxis. Conclusion: The present exploratory study with small sample size showed that inter-individual differences in diversity of gut microbiota were high at baseline, yet quinolone prophylaxis had only a moderate impact. High relative abundances of Enterobacteriaceae during follow-up might indicate failure of or non-adherence to quinolone prophylaxis. However, our results may not be clinically significant given the limitations of the study and therefore future studies are needed to furth

Sphingosine‐1‐phosphate (S1P) regulates pathophysiological processes, including liver regeneration, vascular tone control, and immune response. In patients with liver cirrhosis, acute deterioration of liver function is associated with high mortality rates. The present study investigated whether serum S1P concentrations are associated with disease severity in patients with chronic liver disease from compensated cirrhosis (CC), acute decompensation (AD), or acute‐on‐chronic liver failure (ACLF). From August 2013 to October 2017, patients who were admitted to the University Hospital Frankfurt with CC, AD, or ACLF were enrolled in our cirrhosis cohort study. Tandem mass spectrometry was performed on serum samples of 127 patients to assess S1P concentration. Our study comprised 19 patients with CC, 55 with AD, and 51 with ACLF, aged 29 to 76 years. We observed a significant decrease of S1P according to advanced liver injury from CC and AD up to ACLF (P < 0.001). S1P levels further decreased with progression to ACLF grade 3 (P < 0.05), and S1P highly inversely correlated with the Model for End‐Stage Liver Disease score (r = −0.508; P < 0.001). In multivariate analysis, S1P remained an independent predictor of 7‐day mortality with high diagnostic accuracy (area under the curve, 0.874; P < 0.001). Conclusion: In patients with chronic liver disease, serum S1P levels dramatically decreased with advanced stages of liver disease and were predictive of early mortality. Because S1P is a potent regulator of endothelial integrity and immune response, low S1P levels may significantly influence progressive multiorgan failure. Our data justify further elucidation of the diagnostic and therapeutic role of S1P in ACLF.

Background: While systemic inflammation is recognized as playing a central role in the pathogenesis of organ failures in patients with liver cirrhosis, less is known about its relevance in the development of classical hepatic decompensation. Aim: To characterize the relationship between systemic inflammation, hemodynamics, and anemia with decompensation of liver cirrhosis. Methods: This is a post-hoc analysis of a cohort study of outpatients with advanced liver fibrosis or cirrhosis. Results: Analysis included 338 patients of whom 51 patients (15%) were hospitalized due to decompensation of liver cirrhosis during a median follow-up time of six months. In univariate analysis, active alcoholism (p = 0.002), model of end-stage liver disease (MELD) score (p = 0.00002), serum IL-6 concentration (p = 0.006), heart rate (p = 0.03), low arterial blood pressure (p < 0.05), maximal portal venous flow (p = 0.008), and low hemoglobin concentration (p < 0.00001) were associated with hospitalization during follow-up. Multivariate analysis revealed an independent association of low hemoglobin (OR = 0.62, 95% CI = 0.51–0.78, p = 0.001) and serum IL-6 concentration (OR = 1.02, 95% CI = 1.01–1.04, p = 0.03)—but not of hemodynamic parameters—with hepatic decompensation. An inverse correlation between hemoglobin concentration and portal venous flow (R = −0.362, p < 0.0001) was detected for the non-hospitalized patients. Accuracy of baseline hemoglobin levels for predicting hospitalization (AUC = 0.84, p < 0.000001) was high. Conclusion: Anemia and systemic inflammation, rather than arterial circulatory dysfunction, are strong and independent predictors of hepatic decompensation in outpatients with liver cirrhosis.

Alcoholism is one of the leading and increasingly prevalent reasons of liver associated morbidity and mortality worldwide. Alcoholic hepatitis (AH) constitutes a severe disease with currently no satisfying treatment options. Lipoxin A4 (LXA4), a 15-lipoxygenase (ALOX15)-dependent lipid mediator involved in resolution of inflammation, showed promising pre-clinical results in the therapy of several inflammatory diseases. Since inflammation is a main driver of disease progression in alcoholic hepatitis, we investigated the impact of endogenous ALOX15-dependent lipid mediators and exogenously applied LXA4 on AH development. A mouse model for alcoholic steatohepatitis (NIAAA model) was tested in Alox12/15+/+ and Alox12/15−/− mice, with or without supplementation of LXA4. Absence of Alox12/15 aggravated parameters of liver disease, increased hepatic immune cell infiltration in AH, and elevated systemic neutrophils as a marker for systemic inflammation. Interestingly, i.p. injections of LXA4 significantly lowered transaminase levels only in Alox12/15−/− mice and reduced hepatic immune cell infiltration as well as systemic inflammatory cytokine expression in both genotypes, even though steatosis progressed. Thus, while LXA4 injection attenuated selected parameters of disease progression in Alox12/15−/− mice, its beneficial impact on immunity was also apparent in Alox12/15+/+ mice. In conclusion, pro-resolving lipid mediators may be beneficial to reduce inflammation in alcoholic hepatitis.

BACKGROUND While systemic inflammation is recognized as playing a central role in the pathogenesis of organ failures in patients with liver cirrhosis, less is known about its relevance in the development of classical hepatic decompensation. AIM To characterize the relationship between systemic inflammation, hemodynamics, and anemia with decompensation of liver cirrhosis. METHODS This is a post-hoc analysis of a cohort study of outpatients with advanced liver fibrosis or cirrhosis. RESULTS Analysis included 338 patients of whom 51 patients (15%) were hospitalized due to decompensation of liver cirrhosis during a median follow-up time of six months. In univariate analysis, active alcoholism (p = 0.002), model of end-stage liver disease (MELD) score (p = 0.00002), serum IL-6 concentration (p = 0.006), heart rate (p = 0.03), low arterial blood pressure (p < 0.05), maximal portal venous flow (p = 0.008), and low hemoglobin concentration (p < 0.00001) were associated with hospitalization during follow-up. Multivariate analysis revealed an independent association of low hemoglobin (OR = 0.62, 95% CI = 0.51-0.78, p = 0.001) and serum IL-6 concentration (OR = 1.02, 95% CI = 1.01-1.04, p = 0.03)-but not of hemodynamic parameters-with hepatic decompensation. An inverse correlation between hemoglobin concentration and portal venous flow (R = -0.362, p < 0.0001) was detected for the non-hospitalized patients. Accuracy of baseline hemoglobin levels for predicting hospitalization (AUC = 0.84, p < 0.000001) was high. CONCLUSION Anemia and systemic inflammation, rather than arterial circulatory dysfunction, are strong and independent predictors of hepatic decompensation in outpatients with liver cirrhosis.

Background: Prostanoids are important regulators of platelet aggregation and thrombotic arterial diseases. Their involvement in the development of portal vein thrombosis, frequent in decompensated liver cirrhosis, is still not investigated. Methods: Therefore, we used pro-thrombotic venous milieu generation by bare metal stent transjugular intrahepatic portosystemic shunt insertion, to study the role of prostanoids in decompensated liver cirrhosis. Here, 89 patients receiving transjugular intrahepatic portosystemic shunt insertion were included in the study, and baseline levels of thromboxane B2, prostaglandin D2 and prostaglandin E2 were measured in the portal and the hepatic vein. Results: While the hepatic vein contained higher levels of thromboxane B2 than the portal vein, levels of prostaglandin E2 and D2 were higher in the portal vein (all P<0.0001). Baseline concentrations of thromboxane B2 in the portal vein were independently associated with an increase of portal hepatic venous pressure gradient during short term follow-up, as an indirect sign of thrombogenic potential (multivariable P = 0.004). Moreover, severity of liver disease was inversely correlated with portal as well as hepatic vein levels of prostaglandin D2 and E2 (all P<0.0001). Conclusions: Elevated portal venous thromboxane B2 concentrations are possibly associated with the extent of thrombogenic potential in patients with decompensated liver cirrhosis. Trial registration: ClinicalTrials.gov identifier: NCT03584204.

Background: Liver cirrhosis is associated with profound immunodysfunction, i.e. a parallel presence of chronic systemic inflammation and immunosuppression, which can result in acute-on-chronic liver failure (ACLF). Omega-3 fatty acids are precursors of pro-resolving mediators and support the resolution of inflammation. Objective: The aim of this study was to determine plasma levels of omega-3 fatty acids in patients with liver cirrhosis and ACLF. Methods: Patients with liver cirrhosis with and without ACLF were enrolled in a prospective cohort study and analyzed post-hoc for the present sub-study. Clinical data and biomaterials were collected at baseline and at day 7, 28 and after 3 months of follow-up. Plasma concentrations of arachidonic acid (ARA) and docosahexaenoic acid (DHA), which represent key omega-6 and -3 fatty acids, respectively, were quantified and associated with markers of systemic inflammation and severity of liver cirrhosis. Results: A total of 117 patients were included in the present analyses. Of those, 26 (22.2%), 51 (43.6%) and 40 (34.2%) patients had compensated or decompensated liver cirrhosis, and ACLF. Plasma levels of ARA and DHA were similar in patients with compensated cirrhosis, decompensated cirrhosis, and ACLF. Furthermore, no significant association between plasma ARA or DHA and C-reactive protein or peripheral blood leukocytes were observed (P>0.05). Conclusion: In our study plasma levels of key omega-3 and omega-6 fatty acid are neither associated with the severity of liver cirrhosis nor with liver-cirrhosis-associated systemic inflammation.

Background: Vitamin D is required to maintain the integrity of the intestinal barrier and inhibits inflammatory signaling pathways. Objective: Vitamin D deficiency might be involved in cirrhosis-associated systemic inflammation and risk of hepatic decompensation in patients with liver cirrhosis. Methods: Outpatients of the Hepatology Unit of the University Hospital Frankfurt with advanced liver fibrosis and cirrhosis were prospectively enrolled. 25-hydroxyvitamin D (25(OH)D3) serum concentrations were quantified and associated with markers of systemic inflammation / intestinal bacterial translocation and hepatic decompensation. Results: A total of 338 patients with advanced liver fibrosis or cirrhosis were included. Of those, 51 patients (15%) were hospitalized due to hepatic decompensation during follow-up. Overall, 72 patients (21%) had severe vitamin D deficiency. However, patients receiving vitamin D supplements had significantly higher 25(OH)D3 serum levels compared to patients without supplements (37 ng/mL vs. 16 ng/ml, P<0.0001). Uni- and multivariate analyses revealed an independent association of severe vitamin D deficiency with the risk of hepatic decompensation during follow-up (multivariate P = 0.012; OR = 3.25, 95% CI = 1.30–8.2), together with MELD score, low hemoglobin concentration, low coffee consumption, and presence of diabetes. Of note, serum levels of C-reactive protein, IL-6 and soluble CD14 were significantly higher in patients with versus without severe vitamin D deficiency, and serum levels of soluble CD14 levels declined in patients with de novo supplementation of vitamin D (median 2.15 vs. 1.87 ng/mL, P = 0.002). Conclusions: In this prospective cohort study, baseline vitamin D levels were inversely associated with liver-cirrhosis related systemic inflammation and the risk of hepatic decompensation.

Most studies in the life sciences and other disciplines involve generating and analyzing numerical data of some type as the foundation for scientific findings. Working with numerical data involves multiple challenges. These include reproducible data acquisition, appropriate data storage, computationally correct data analysis, appropriate reporting and presentation of the results, and suitable data interpretation. Finding and correcting mistakes when analyzing and interpreting data can be frustrating and time-consuming. Presenting or publishing incorrect results is embarrassing but not uncommon. Particular sources of errors are inappropriate use of statistical methods and incorrect interpretation of data by software. To detect mistakes as early as possible, one should frequently check intermediate and final results for plausibility. Clearly documenting how quantities and results were obtained facilitates correcting mistakes. Properly understanding data is indispensable for reaching well-founded conclusions from experimental results. Units are needed to make sense of numbers, and uncertainty should be estimated to know how meaningful results are. Descriptive statistics and significance testing are useful tools for interpreting numerical results if applied correctly. However, blindly trusting in computed numbers can also be misleading, so it is worth thinking about how data should be summarized quantitatively to properly answer the question at hand. Finally, a suitable form of presentation is needed so that the data can properly support the interpretation and findings. By additionally sharing the relevant data, others can access, understand, and ultimately make use of the results. These quick tips are intended to provide guidelines for correctly interpreting, efficiently analyzing, and presenting numerical data in a useful way.

Die Leber nimmt eine zentrale Rolle im Metabolismus ein. Sie speichert Kohlenhydrate in Form von Glykogen und entgiftet den Körper z.B. von Alkohol. Die Leber besitzt neben einem arteriellen auch einen venösen Zufluss, die Portalvene. Diese Vene transportiert nährstoffreiches Blut aus dem Gastrointestinaltrakt zur Leber, das auch eine hohe Konzentration an Metaboliten bakteriellen Ursprungs aufweist. Daher sorgen die residenten Immunzellen in der Leber stets für einen Zustand der Toleranz, d.h. es findet keine pro-inflammatorische Antwort auf den jeweiligen Stimulus statt. Dennoch muss das Immunsystem der Leber auch in der Lage sein, Infektionen effektiv zu bekämpfen. Belastungen der Leber z.B. durch Alkoholkonsum, zu fettreiche Nahrung, Infektionen oder Toxine können zu Leberzirrhose führen. Das akut-auf-chronische-Leberversagen ist die schwerste klinische Folgeerscheinung. Forschungsergebnisse zeigen sowohl Anzeichen von einer Überreaktion des Immunsystem als auch einer Immunparalyse bei den Patienten. Das Zytokin Interleukin-7 ist von zentraler Bedeutung bei der Reifung von Zellen des adaptiven Immunsystems. Auch in Leber und Darm sorgt Interleukin-7 für den Aufbau und Erhalt von verschiedenen Immunzellen. Eine Studie in Mäusen konnte zeigen, dass sich in den Lebern der Tiere Interleukin-7 induzieren ließ, wenn ihnen bakterielles Lipopolysaccharid in die Portalvene gespritzt wurde. Anhand dieser Datenlage ergaben sich die Fragestellung dieser Doktorarbeit, wie sich die genaue Rolle von Interleukin-7 in gesunden und zirrhotischen Lebern definieren lässt. Um diese Frage zu klären, wurden zumeist Versuche in Zellkultur genutzt. Die Expression von Interleukin-7 in Hepatozyten und Endothelzellen wurde auf RNA Ebene im Zelllysat oder auf Proteinebene im Zellkulturüberstand überprüft. Mittels siRNA Transfektion wurden gezielt Mediatoren der Signalkaskade supprimiert. Verschiedene Immunzellen wurden aus humanem Blut aufgereingt und die Präsenz der Rezeptorproteine für In, The liver as the biggest endocrine gland of the human body plays a central role in many metabolic pathways such as detoxification, storage of carbohydrates and distribution of lipids. As the liver receives blood supply from the gut by the portal vein, liver cells are often challenged with high concentrations of nutrients and components of our commensal microbiota. Therefore, the immune system of the liver induces a tolerant state, meaning no or low inflammatory reactions to those constant stimuli. Yet, as various pathogens target the liver, the hepatic immune system also needs the capability to induce strong immune responses quickly. Chronical damage to the liver, which can be caused by alcohol, pathogens or toxins, might lead to liver cirrhosis, where the amount of functional liver tissue is decreased dramatically. This pathology can worsen and lead to acute-on-chronic liver failure, whose high mortality is due to high inflammation and multi-organ failure. Interleukin-7 is a cytokine known for its pro-survival functions especially in lymphopoiesis. However, it is also very important for maintenance of mature immune cells in the liver. As mouse experiments have demonstrated an induction of Interleukin-7 in the liver as a response to bacterial lipopolysaccharide, we aimed to characterize the role of Interleukin-7 in hepatic immunoregulation in both health and disease. The experiments were mostly based on in vitro approaches. Induction of Interleukin-7 in liver cells was analyzed using ELISA, quantitative PCR, and Immunoblotting. Knockdown of signal transduction components was performed by siRNA transfection. Primary immune cells isolated from healthy donor buffy coat were studied for their ability to respond to Interleukin-7. Activation of downstream signal transduction was assessed by Immunoblotting. Functional consequences of Interleukin-7 signaling, such as alterations in cellular metabolism, cellular survival and endotoxin tolerance, were studied in monocyte-deri

Single nucleotide polymorphism (SNP) rs738409 C>G in the patatin‐like phospholipase domain containing 3 (PNPLA3) gene results in an amino acid exchange from isoleucin to methionine at position I148M of PNPLA3. The expression of this loss‐of‐function mutation leads to impaired hepatocellular triglyceride hydrolysis and is associated with the development of liver steatosis, fibrosis, and hepatocellular carcinoma. In contrast to these well‐established associations, the relationship of the PNPLA3 rs738409 variant with other metabolic traits is incompletely understood. We therefore assessed the association of the PNPLA3 rs738409 genotype with relevant metabolic traits in a prospective study of patients at high risk for cardiovascular events, i.e., patients undergoing coronary angiography. In a total of 270 patients, known associations of the PNPLA3 rs738409 GG genotype with nonalcoholic steatohepatitis and liver fibrosis were confirmed. In addition, we found an association of the PNPLA3 rs738409 G allele with the presence of diabetes (22% versus 28% versus 58% for CC versus CG versus GG genotype, respectively; P = 0.02). In contrast to its association with nonalcoholic fatty liver disease, liver fibrosis, and diabetes, the minor G allele of PNPLA3 rs738409 was inversely associated with total serum cholesterol and low‐density lipoprotein serum levels (P = 0.003 and P = 0.02, respectively). Finally, there was a trend toward an inverse association between the presence of the PNPLA3 rs738409 G allele and significant coronary heart disease. Comparable trends were observed for the transmembrane 6 superfamily member 2 (TM6SF2) 167 K variant, but the sample size was too small to evaluate this rarer variant. Conclusion: The PNPLA3 rs738409 G allele is associated with liver disease but also with a relatively benign cardiovascular risk profile.

Extracellular vesicles (EVs) are increasingly recognized as important mediators of intercellular communication. In this study, we aimed to further characterize the role of macrophage-derived EVs in immune responses against hepatitis C virus (HCV) and the potential of polyunsaturated fatty acids (PUFAs) to modulate this modality of innate immunity. To this end, EVs were isolated from interferon-stimulated macrophage cultures or from serum of patients with acute or chronic hepatitis C. EVs were characterized by electron microscopy, flow cytometry, RNA-sequencing, and Western blot analysis. The effect of EVs on replication of HCV was assessed in coculture models. Functional analyses were performed to assess the impact of PUFAs on EV-mediated antiviral immunity. We found that macrophages secreted various cytokines shortly after stimulation with type I and II IFN, which orchestrated a fast but short-lasting antiviral state. This rapid innate immune answer was followed by the production of macrophage-derived EVs, which induced a late, but long-lasting inhibitory effect on HCV replication. Of note, exposure of macrophages to PUFAs, which are important regulators of immune responses, dampened EV-mediated antiviral immune responses. Finally, EVs from patients with hepatitis C exhibited long-lasting antiviral activities during IFN therapy as well. The antiviral effect of EVs from Caucasian and Japanese patients differed, which may be explained by different nutritional uptake of PUFAs. In conclusion, our data indicate that macrophage-derived EVs mediate long-lasting inhibitory effects on HCV replication, which may bridge the time until efficient adaptive immune responses are established, and which can be blunted by PUFAs.