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Assessing immune responses to cytomegalovirus (CMV) after liver transplant in patients on immunosuppressive therapy remains challenging. In this study, employing ELISPOT assays, 52 liver-transplant recipients were evaluated for antiviral T-cell activity in peripheral blood mononuclear cells (PBMCs), measuring interferon-γ (IFN-γ) secretion upon stimulation with CMV-specific peptides (CMV peptide pool, CMV IE-1, and pp65 antigens). Parameters such as stimulation index, mean spot size, and mean spot count were measured. The study found that heightened immunosuppression, especially with prednisolone in triple therapy, significantly dampened CMV-specific immune responses. This was demonstrated by decreased IFN-γ production by CMV-specific T-cells (CMV peptide pool: p = 0.036; OR = 0.065 [95% CI: 0.005–0.840], pp65 antigen: p = 0.026; OR = 0.048 [95% CI: 0.003–0.699]). Increased immunosuppression correlated with reduced IFN-γ secretion per cell, reflected in smaller mean spot sizes for the CMV peptide pool (p = 0.019). Notably, shorter post-transplant intervals correlated with diminished antiviral T-cell IFN-γ release at two years (CMV peptide pool: p = 0.019; IE antigen: p = 0.010) and five years (CMV peptide pool: p = 0.0001; IE antigen: p = 0.002; pp65 antigen: p = 0.047), as did advancing age (pp65 antigen: p = 0.016, OR = 0.932, 95% CI: 0.881–0.987). Patients with undetectable CMV antigens had a notably higher risk of CMV reactivation within six months from blood collection, closely linked with triple immunosuppression and prednisolone use. These findings highlight the intricate interplay between immunosuppression, immune response dynamics, and CMV reactivation risk, emphasizing the necessity for tailored immunosuppressive strategies to mitigate CMV reactivation in liver-transplant recipients. It can be concluded that, particularly in the early months post-transplantation, the use of prednisolone as a third immunosuppressant should be critically reconsidered. Additionally, the use of prophylactic antiviral therapy effective against CMV in this context holds significant importance.

Background: Liver transplant recipients often require endoscopic retrograde cholangiopancreatography (ERCP) for biliary complications, which can lead to infections. This retrospective single-center study aimed to identify risk factors for infectious complications following ERCP in liver transplant patients. Methods: A retrospective analysis was conducted on 285 elective ERCP interventions performed in 88 liver transplant patients at a tertiary care center. The primary endpoint was the occurrence of an infection following ERCP. Univariable and multivariable regression analyses, Cox regression, and log-rank tests were employed to assess the influence of various factors on the incidence of infectious complications. Results: Among the 285 ERCP interventions, isolated anastomotic stenosis was found in 175 cases, ischemic type biliary lesion (ITBL) in 103 cases, and choledocholithiasis in seven cases. Bile duct interventions were performed in 96.9% of all ERCPs. Infections after ERCP occurred in 46 cases (16.1%). Independent risk factors for infection included male sex (OR 24.19), prednisolone therapy (OR 4.5), ITBL (OR 4.51), sphincterotomy (OR 2.44), cholangioscopy (OR 3.22), dilatation therapy of the bile ducts (OR 9.48), and delayed prophylactic antibiotic therapy (>1 h after ERCP) (OR 2.93). Additionally, infections following previous ERCP interventions were associated with an increased incidence of infections following future ERCP interventions (p < 0.0001). Conclusion: In liver transplant patients undergoing ERCP, male sex, prednisolone therapy, and complex bile duct interventions independently raised infection risks. Delayed antibiotic treatment further increased this risk. Patients with ITBL were notably susceptible due to incomplete drainage. Additionally, a history of post-ERCP infections signaled higher future risks, necessitating close monitoring and timely antibiotic prophylaxis.

Acute-on-chronic liver failure (ACLF) is associated with increased mortality. Specific therapy options are limited. Hypoxia-inducible factor 1 alpha (HIF-1α) has been linked to the pathogenesis of chronic liver disease (CLD), but the role of HIF-1α in ACLF is poorly understood. In the current study, different etiologies of CLD and precipitating events triggering ACLF were used in four rodent models. HIF-1α expression and the intracellular pathway of HIF-1α induction were investigated using real-time quantitative PCR. The results were verified by Western blotting and immunohistochemistry for extrahepatic HIF-1α expression using transcriptome analysis. Exploratory immunohistochemical staining was performed to assess HIF-1α in human liver tissue. Intrahepatic HIF-1α expression was significantly increased in all animals with ACLF, regardless of the underlying etiology of CLD or the precipitating event. The induction of HIF-1α was accompanied by the increased mRNA expression of NFkB1 and STAT3 and resulted in a marked elevation of mRNA levels of its downstream genes. Extrahepatic HIF-1α expression was not elevated. In human liver tissue samples, HIF-1α expression was elevated in CLD and ACLF. Increased intrahepatic HIF-1α expression seems to play an important role in the pathogenesis of ACLF, and future studies are pending to investigate the role of therapeutic HIF inhibitors in ACLF.

Malignancies can cause severe stenosis of the biliary tract and therefore predispose a patient to bacterial cholangitis. Upon endoscopic drainage, antibiotic therapy (AT) is performed according to individual clinical judgement, as the optimal duration of AT is unclear to date, especially in the case of multidrug-resistant organisms (MDROs). In a case-based retrospective study, patients with malignant biliary strictures and acute cholangitis were included upon endoscopic retrograde cholangiography (ERC). The outcome of cases treated with short AT (≤6 days) was compared to that of long AT (≥7 days). Recurrent cholangitis (RC) before scheduled stent exchange was the primary end point. In total, 124 patients were included, with 183 cases of proven cholangitis in total. The overall median duration of AT was 7 days (range 1–20), with 74 cases (40%) receiving short AT and 109 (60%) receiving long AT. Short AT was not an independent risk factor for RC (HR = 0.66, p > 0.2), while colonization with MDROs was associated with a higher risk of RC (HR = 2.21, p = 0.005). Placement of a metal stent was associated with minor risk of RC (HR = 0.4, p = 0.038). In conclusion, short AT is possible in selected patients with non-severe cholangitis and malignant biliary strictures. Scheduled screening for MDROs is recommended and placement of a metal stent should be performed if possible.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease often associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (CU), and rarely with Crohn’s disease (CD). Various long-term analyses show different rates of cancer and the need for orthotopic liver transplantation (OLT) in patients with isolated PSC and with concomitant IBD, respectively. However, data on the detailed course of PSC with or without IBD are limited. We aimed to analyze the clinical disease course of PSC patients without IBD compared to PSC patients with UC and CD, respectively. A retrospective data analysis of patients with isolated PSC (n = 41) and of patients with concomitant IBD (n = 115) was performed. In detail, PSC disease characteristics including occurrence of dominant stenoses, liver cirrhosis, OLT and malignancy, as well as the temporal course of PSC activity and disease progression, were analyzed. A multivariable Cox regression model and a Fine–Gray competing risk model were further used for the independent risk factor analysis of cirrhosis development and OLT. Patients with isolated PSC were significantly older at first diagnosis than patients with PSC-IBD (39 vs. 28 years, p = 0.02). A detailed analysis of the course of PSC revealed a faster PSC progression after initial diagnosis in isolated PSC patients compared to PSC-IBD including significantly earlier diagnosis of dominant stenoses (29 vs. 74 months, p = 0.021) and faster progression to liver cirrhosis (38 vs. 103 months, p = 0.027). Patients with isolated PSC have a higher risk of developing cirrhosis than patients with PSC-IBD (Gray’s test p = 0.03). OLT was more frequently performed in male patients with isolated PSC compared to males with coincident IBD (48% (n = 13) vs. 33% (n = 25), p = 0.003). Colorectal carcinoma was significantly more often diagnosed in patients with PSC-IBD than in isolated PSC (8.7% vs. 0%, p = 0.042). Patients with isolated PSC seem to have a different clinical course of disease than PSC patients with concomitant IBD characterized by a more pro-fibrotic disease course with earlier onset of liver cirrhosis and dominant stenosis but with less malignancy. These data may be interpreted as either a more progressive disease course of isolated PSC or a later diagnosis of the disease at an advanced disease stage. The different clinical courses of PSC and the underlying mechanisms of the gut–liver axis need further attention.

Obesity is characterized by the expansion of the adipose tissue, usually accompanied by inflammation, with a prominent role of macrophages infiltrating the visceral adipose tissue (VAT). This chronic inflammation is a major driver of obesity-associated comorbidities. Four-and-a-half LIM-domain protein 2 (FHL2) is a multifunctional adaptor protein that is involved in the regulation of various biological functions and the maintenance of the homeostasis of different tissues. In this study, we aimed to gain new insights into the expression and functional role of FHL2 in VAT in diet-induced obesity. We found enhanced FHL2 expression in the VAT of mice with Western-type diet (WTD)-induced obesity and obese humans and identified macrophages as the cellular source of enhanced FHL2 expression in VAT. In mice with FHL2 deficiency (FHL2KO), WTD feeding resulted in reduced body weight gain paralleled by enhanced energy expenditure and uncoupling protein 1 (UCP1) expression, indicative of activated thermogenesis. In human VAT, FHL2 was inversely correlated with UCP1 expression. Furthermore, macrophage infiltration and the expression of the chemokine MCP-1, a known promotor of macrophage accumulation, was significantly reduced in WTD-fed FHL2KO mice compared with wild-type (wt) littermates. While FHL2 depletion did not affect the differentiation or lipid metabolism of adipocytes in vitro, FHL2 depletion in macrophages resulted in reduced expressions of MCP-1 and the neuropeptide Y (NPY). Furthermore, WTD-fed FHL2KO mice showed reduced NPY expression in VAT compared with wt littermates, and NPY expression was enhanced in VAT resident macrophages of obese individuals. Stimulation with recombinant NPY induced not only UCP1 expression and lipid accumulation but also MCP-1 expression in adipocytes. Collectively, these findings indicate that FHL2 is a positive regulator of NPY and MCP-1 expression in macrophages and herewith closely linked to the mechanism of obesity-associated lipid accumulation and inflammation in VAT. Thus, FHL2 appears as a potential novel target to interfere with the macrophage–adipocyte crosstalk in VAT for treating obesity and related metabolic disorders.

Introduction: The COVID-19 pandemic is a result of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination against COVID-19 is crucial for preventing severe illness and controlling the pandemic. This study aimed to examine how immunosuppressed patients with inflammatory bowel disease (IBD) responded to the third mRNA vaccination against SARS-CoV-2. The patients were undergoing treatments such as anti-TNF (infliximab, adalimumab), anti-α4ß7 integrin (vedolizumab), anti-IL12/23 (ustekinumab) and azathioprine (purine analog). Their responses were compared to those of healthy individuals. Methods: In this prospective study, 81 IBD patients and 15 healthy controls were enrolled 2–4 months after receiving the third mRNA vaccination. This study measured IgG antibody levels against the SARS-CoV-2 spike protein’s receptor binding domain (RBD) and assessed potential neutralization capacity using a surrogate virus neutralization test (sVNT). Results: Overall, immunosuppressed IBD patients (without SARS-CoV-2 infection) exhibited significantly lower levels of anti-S-IgG (anti-RBD-IgG) and binding inhibition in the sVNT after the third vaccination compared to healthy controls. Patients under anti-TNF therapy showed notably reduced anti-S-IgG levels after the booster vaccination, in contrast to those receiving ustekinumab and azathioprine (p = 0.030, p = 0.031). IBD patients on anti-TNF therapy demonstrated significantly increased anti-S-IgG levels following prior SARS-CoV-2 infection (p = 0.020). Conclusion: Even after the third vaccination, immunosuppressed IBD patients exhibited diminished humoral immunity compared to healthy controls, especially those on anti-TNF therapy. Cases of penetrating infections led to considerably higher antibody levels in IBD patients under anti-TNF therapy compared to uninfected patients. Further investigation through prospective studies in immunosuppressed IBD patients is needed to determine whether this effectively safeguards against future infections or severe disease.

Acute-on-chronic liver failure (ACLF) is a frequent complication in patients with liver cirrhosis that has high short-term mortality. It is characterized by acute decompensation (AD) of liver cirrhosis, intra- and extrahepatic organ failure, and severe systemic inflammation (SI). In the recent past, several studies have investigated the management of this group of patients. Identification and treatment of precipitants of decompensation and ACLF play an important role, and management of the respective intra- and extrahepatic organ failures is essential. However, no specific treatment for ACLF has been established to date, and the only curative treatment option currently available for these patients is liver transplantation (LT). It has been shown that ACLF patients are at severe risk of waitlist mortality, and post-LT survival rates are high, making ACLF patients suitable candidates for LT. However, only a limited number of patients are eligible for LT due to related contraindications such as uncontrolled infections. In this case, bridging strategies (e.g., extracorporeal organ support systems) are required. Further therapeutic approaches have recently been developed and evaluated. Thus, this review focuses on current management and potential future treatment options.

We performed a retrospective single-center analysis to investigate the diagnostic yield of bone marrow puncture in patients with liver cirrhosis and cytopenia. Liver cirrhosis patients receiving bone marrow aspiration or biopsy for the diagnostic work-up of otherwise unexplained peripheral blood cytopenia at our institution between 2004 and 2020 were enrolled in this study. We evaluated findings from cytologic, histologic and immunologic assessment and final diagnostic outcomes. A total of 118 patients with a median age of 55 years and a median Child–Pugh score of B (8 points) were enrolled. The main etiologies of liver cirrhosis were viral hepatitis (B and C) or chronic alcohol consumption. The majority of patients (60%) exhibited concurrent anemia, leukocytopenia and thrombocytopenia. Bone marrow assessment revealed normal, unspecific or reactive alterations in 117 out of 118 patients (99%). One patient was diagnosed with myelodysplastic syndrome. Our findings suggest that peripheral blood cytopenia in patients with liver cirrhosis is rarely associated with a primary bone marrow pathology.

Non-alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) are the leading causes of liver disease worldwide. To identify disease-specific pathomechanisms, we analyzed the lipidome, metabolome and immune cell recruitment in livers in both diseases. Mice harboring ASH or NASH had comparable disease severities regarding mortality rate, neurological behavior, expression of fibrosis marker and albumin levels. Lipid droplet size was higher in NASH than ASH and qualitative differences in the lipidome were mainly based on incorporation of diet-specific fatty acids into triglycerides, phosphatidylcholines and lysophosphatidylcholines. Metabolomic analysis showed downregulated nucleoside levels in both models. Here, the corresponding uremic metabolites were only upregulated in NASH suggesting stronger cellular senescence, which was supported by lower antioxidant levels in NASH as compared to ASH. While altered urea cycle metabolites suggest increased nitric oxide synthesis in both models, in ASH, this depended on increased L-homoarginine levels indicating a cardiovascular response mechanism. Interestingly, only in NASH were the levels of tryptophan and its anti-inflammatory metabolite kynurenine upregulated. Fittingly, high-content immunohistochemistry showed a decreased macrophage recruitment and an increased polarization towards M2-like macrophages in NASH. In conclusion, with comparable disease severity in both models, higher lipid storage, oxidative stress and tryptophan/kynurenine levels were seen in NASH, leading to distinct immune responses.

Ulcerative colitis (UC) is characterized by chronic inflammation of the colorectum. Histological remission has emerged as a potential future treatment goal; however, the histopathological assessment of intestinal inflammation in UC remains challenging with a multitude of available scoring systems and the need for a pathologist with expertise in inflammatory bowel disease (IBD). In previous studies, quantitative phase imaging (QPI) including digital holographic microscopy (DHM) was successfully applied as an objective method for stain-free quantification of the degree of inflammation in tissue sections. Here, we evaluated the application of DHM for the quantitative assessment of histopathological inflammation in patients with UC. In our study, endoscopically obtained colonic and rectal mucosal biopsy samples from 21 patients with UC were analyzed by capturing DHM-based QPI images that were subsequently evaluated using the subepithelial refractive index (RI). The retrieved RI data were correlated with established histological scoring systems including the Nancy index (NI) as well as with endoscopic and clinical findings. As a primary endpoint, we found a significant correlation between the DHM-based retrieved RI and the NI (R2 = 0.251, p < 0.001). Furthermore, RI values correlated with the Mayo endoscopic subscore (MES; R2 = 0.176, p < 0.001). An area under the receiver operating characteristics (ROC) curve of 0.820 confirms the subepithelial RI as a reliable parameter to distinguish biopsies with histologically active UC from biopsies without evidence of active disease as determined by conventional histopathological examination. An RI higher than 1.3488 was found to be the most sensitive and specific cut-off value to identify histologically active UC (sensitivity of 84% and specificity of 72%). In conclusion, our data demonstrate DHM to be a reliable tool for the quantitative assessment of mucosal inflammation in patients with UC.

Chronic hepatitis B virus (HBV) infection is a global health threat. Mutations in the surface antigen of HBV (HBsAg) may alter its antigenicity, infectivity, and transmissibility. A patient positive for HBV DNA and detectable but low-level HBsAg in parallel with anti-HBs suggested the presence of immune and/or diagnostic escape variants. To support this hypothesis, serum-derived HBs gene sequences were amplified and cloned for sequencing, which revealed infection with exclusively non-wildtype HBV subgenotype (sgt) D3. Three distinct mutations in the antigenic loop of HBsAg that caused additional N-glycosylation were found in the variant sequences, including a previously undescribed six-nucleotide insertion. Cellular and secreted HBsAg was analyzed for N-glycosylation in Western blot after expression in human hepatoma cells. Secreted HBsAg was also subjected to four widely used, state-of-the-art diagnostic assays, which all failed to detect the hyperglycosylated insertion variant. Additionally, the recognition of mutant HBsAg by vaccine- and natural infection-induced anti-HBs antibodies was severely impaired. Taken together, these data suggest that the novel six-nucleotide insertion as well as two other previously described mutations causing hyperglycosylation in combination with immune escape mutations have a critical impact on in vitro diagnostics and likely increase the risk of breakthrough infection by evasion of vaccine-induced immunity.

In the current era of precision oncology, it is widely acknowledged that CRC is a heterogeneous disease entity. Tumor location (right- or left-sided colon cancer or rectal cancer) is a crucial factor in determining disease progression as well as prognosis and influences disease management. In the last decade, numerous works have reported that the microbiome is an important element of CRC carcinogenesis, progression and therapy response. Owing to the heterogeneous nature of microbiomes, the findings of these studies were inconsistent. The majority of the studies combined colon cancer (CC) and rectal cancer (RC) samples as CRC for analysis. Furthermore, the small intestine, as the major site for immune surveillance in the gut, is understudied compared to the colon. Thus, the CRC heterogeneity puzzle is far from being solved, and more research is necessary for prospective trials that separately investigate CC and RC. Our prospective study aimed to map the colon cancer landscape using 16S rRNA amplicon sequencing in biopsy samples from the terminal ileum, healthy colon tissue, healthy rectal tissue and tumor tissue as well as in preoperative and postoperative stool samples of 41 patients. While fecal samples provide a good approximation of the average gut microbiome composition, mucosal biopsies allow for detecting subtle variations in local microbial communities. In particular, the small bowel microbiome has remained poorly characterized, mainly because of sampling difficulties. Our analysis revealed the following: (i) right- and left-sided colon cancers harbor distinct and diverse microbiomes, (ii) the tumor microbiome leads to a more consistent cancer-defined microbiome between locations and reveals a tumor microbiome–ileal microbiome association, (iii) the stool only partly reflects the microbiome landscape in patients with CC, and (iv) mechanical bowel preparation and perioperative antibiotics together with surgery result in major changes in the stool microbiome, characterized by a significant increase in the abundance of potentially pathogenic bacteria, such as Enterococcus. Collectively, our results provide new and valuable insights into the complex microbiome landscape in patients with colon cancer.

The NO-cGMP signal transduction pathway plays a crucial role in tone regulation in hepatic sinusoids and peripheral blood vessels. In a cirrhotic liver, the key enzymes endothelial NO synthase (eNOS), soluble guanylate cyclase (sGC), and phosphodiesterase-5 (PDE-5) are overexpressed, leading to decreased cyclic guanosine-monophosphate (cGMP). This results in constriction of hepatic sinusoids, contributing about 30% of portal pressure. In contrast, in peripheral arteries, dilation prevails with excess cGMP due to low PDE-5. Both effects eventually lead to circulatory dysfunction in progressed liver cirrhosis. The conventional view of portal hypertension (PH) pathophysiology has been described using the “NO-paradox”, referring to reduced NO availability inside the liver and elevated NO production in the peripheral systemic circulation. However, recent data suggest that an altered availability of cGMP could better elucidate the contrasting findings of intrahepatic vasoconstriction and peripheral systemic vasodilation than mere focus on NO availability. Preclinical and clinical data have demonstrated that targeting the NO-cGMP pathway in liver cirrhosis using PDE-5 inhibitors or sGC stimulators/activators decreases intrahepatic resistance through dilation of sinusoids, lowering portal pressure, and increasing portal venous blood flow. These results suggest further clinical applications in liver cirrhosis. Targeting the NO-cGMP system plays a role in possible reversal of liver fibrosis or cirrhosis. PDE-5 inhibitors may have therapeutic potential for hepatic encephalopathy. Serum/plasma levels of cGMP can be used as a non-invasive marker of clinically significant portal hypertension. This manuscript reviews new data about the role of the NO-cGMP signal transduction system in pathophysiology of cirrhotic portal hypertension and provides perspective for further studies.

Transjugular intrahepatic portosystemic shunt (TIPS) is the most effective measure to treat complications of portal hypertension. However, liver function may deteriorate after TIPS. Predictors of liver function and outcome after TIPS are therefore important for management of TIPS patients. The study aimed to evaluate the impact of liver volume on transplant-free survival (TFS) after TIPS, as well as the evolution of liver volume and its relationship with liver function after TIPS. A retrospective analysis of all consecutive patients who underwent TIPS in a tertiary care university liver center between 2012 and 2017 (n = 216) was performed; n = 72 patients with complete prior and follow-up (FU) computed tomography (CT) imaging studies were included in the study. Volumetry of the liver was performed by a semi-automatic 9-lobe image segmentation algorithm at baseline and FU (FU 1: 90–180 d; FU 2: 180–365 d; FU 3: 365–545 d; FU 4: 545–730 d; FU 5: >730 d). Output variables were total liver volume (TLV, cm3), left liver volume (LLV, cm3), right liver volume (RLV, cm3) and TLV/body weight ratio. CT derived liver volumes were correlated with liver function tests, portosystemic pressure gradient (PPG) measurements and survival. To assess predictors of liver volume change over time we fitted linear mixed models. Kaplan–Meier analysis was performed and validated by matched pair analysis followed by Cox regression to determine independent prognostic factors for survival. The median TLV at baseline was 1507.5 cm3 (773.7–3686.0 cm3). Livers with higher baseline liver volumes and larger TLV/weight ratios retained their volume after an initial loss while smaller livers continuously lost volume after TIPS. At the first follow-up period (90–180 d post-TIPS) lower liver volumes and TLV/weight ratios were associated with higher bilirubin levels. Within the final multivariable model containing time (days since TIPS), baseline INR and baseline TLV, the average loss of liver volume was 0.74 mL per day after TIPS. Twelve-month overall transplant-free survival was 89% and median overall TFS was 33 months. The median TFS for a baseline TLV/body weight ratio > 20 was significantly higher compared with ≤20 (40.0 vs. 27.0 months, p = 0.010) while there were no differences regarding the indication for TIPS or etiology of liver disease in the matched pair analysis. Lower TLV/weight ratios before TIPS were associated with shorter TFS and should therefore be critically considered when selecting patients for TIPS. In addition, this study provides first evidence of an effect of TIPS on subsequent liver volume change and associated liver function.

Transjugular intrahepatic portosystemic shunt (TIPS) is an established treatment tool in decompensated liver cirrhosis that has been shown to prolong transplant-free survival. Hepatic encephalopathy (HE) is a frequent complication of decompensated cirrhosis, eventually induced and/or aggravated by TIPS, that remains a clinical challenge especially in these patients. Therefore, patient selection for TIPS requires careful assessment of risk factors for HE. TIPS procedural parameters regarding stent size and invasive portosystemic pressure gradient measurements thereby have an important role. Endovascular shunt modification, in combination with a conservative medical approach, often results in a significant reduction of symptoms. This review summarizes HE molecular mechanisms and pathophysiology as well as diagnostic and therapeutic approaches targeting shunt-induced HE.

Background. Bariatric surgery is a widely used treatment for morbid obesity. Prediction of postoperative weight loss currently relies on prediction models, which mostly overestimate patients’ weight loss. Data about the influence of Non-alcoholic fatty liver disease (NAFLD) on early postoperative weight loss are scarce. Methods. This prospective, single-center cohort study included 143 patients receiving laparoscopic gastric bypass surgery (One Anastomosis-Mini Gastric Bypass (OAGB-MGB) or Roux-en-Y Gastric Bypass (RYGB)). Liver biopsies were acquired at surgery. NAFLD activity score (NAS) assigned patients to “No NAFLD”, “NAFL” or “NASH”. Follow up data were collected at 3, 6 and 12 months. Results. In total, 49.7% of patients had NASH, while 41.3% had NAFL. Compared with the No NAFLD group, NAFL and NASH showed higher body-mass-index (BMI) at follow-up (6 months: 31.0 kg/m2 vs. 36.8 kg/m2 and 36.1 kg/m2, 12 months: 27.0 kg/m2 vs. 34.4 and 32.8 kg/m2) and lower percentage of total body weight loss (%TBWL): (6 months: 27.1% vs. 23.3% and 24.4%; 12 months: 38.5% vs. 30.1 and 32.6%). Linear regression of NAS points significantly predicts percentage of excessive weight loss (%EWL) after 6 months (Cologne-weight-loss-prediction-score). Conclusions. Histopathological presence of NAFLD might lead to inferior postoperative weight reduction after gastric bypass surgery. The mechanisms underlying this observation should be further studied.

Liver cirrhosis is a frequent condition with high impact on patients’ life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to morphological remodeling of the organ, a functional dysregulation of the sinusoids, the smallest functional units of liver vasculature, plays a pivotal role. Vascular tone is primarily regulated by the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, wherein soluble guanylate cyclase (sGC) and phosphodiesterase-5 (PDE-5) are key enzymes. Recent data showed characteristic alterations in the expression of these regulatory enzymes or metabolite levels in liver cirrhosis. Additionally, a disturbed zonation of the components of this pathway along the sinusoids was detected. This review describes current knowledge of the pathophysiology of PH with focus on the enzymes regulating cGMP availability, i.e., sGC and PDE-5. The results have primarily been obtained in animal models of liver cirrhosis. However, clinical and histochemical data suggest that the new biochemical model we propose can be applied to human liver cirrhosis. The role of PDE-5 as potential target for medical therapy of PH is discussed.

Postoperative complications after pancreatic surgery are still a significant problem in clinical practice. The aim of this study was to characterize and compare the microbiomes of different body compartments (bile duct, duodenal mucosa, pancreatic tumor lesion, postoperative drainage fluid, and stool samples; preoperative and postoperative) in patients undergoing pancreatic surgery for suspected pancreatic cancer, and their association with relevant clinical factors (stent placement, pancreatic fistula, and gland texture). For this, solid (duodenal mucosa, pancreatic tumor tissue, stool) and liquid (bile, drainage fluid) biopsy samples of 10 patients were analyzed using 16s rRNA gene next-generation sequencing. Our analysis revealed: (i) a distinct microbiome in the different compartments, (ii) markedly higher abundance of Enterococcus in patients undergoing preoperative stent placement in the common bile duct, (iii) significant differences in the beta diversity between patients who developed a postoperative pancreatic fistula (POPF B/C), (iv) patients with POPF B/C were more likely to have bacteria belonging to the genus Enterococcus, and (v) differences in microbiome composition with regard to the pancreatic gland texture. The structure of the microbiome is distinctive in different compartments, and can be associated with the development of a postoperative pancreatic fistula.

Macrophages facilitate essential homeostatic functions e.g., endocytosis, phagocytosis, and signaling during inflammation, and express a variety of scavenger receptors including CD163 and CD206, which are upregulated in response to inflammation. In healthy individuals, soluble forms of CD163 and CD206 are constitutively shed from macrophages, however, during inflammation pathogen- and damage-associated stimuli induce this shedding. Activation of resident liver macrophages viz. Kupffer cells is part of the inflammatory cascade occurring in acute and chronic liver diseases. We here review the existing literature on sCD163 and sCD206 function and shedding, and potential as biomarkers in acute and chronic liver diseases with a particular focus on Acute-on-Chronic Liver Failure (ACLF). In multiple studies sCD163 and sCD206 are elevated in relation to liver disease severity and established as reliable predictors of morbidity and mortality. However, differences in expression- and shedding-stimuli for CD163 and CD206 may explain dissimilarities in prognostic utility in patients with acute decompensation of cirrhosis and ACLF.

Non-alcoholic fatty liver disease (NAFLD) is gaining in importance and is linked to obesity. Especially, the development of fibrosis and portal hypertension in NAFLD patients requires treatment. Transgenic TGR(mREN2)27 rats overexpressing mouse renin spontaneously develop NAFLD with portal hypertension but without obesity. This study investigated the additional role of obesity in this model on the development of portal hypertension and fibrosis. Obesity was induced in twelve-week old TGR(mREN2)27 rats after receiving Western diet (WD) for two or four weeks. Liver fibrosis was assessed using standard techniques. Hepatic expression of transforming growth factor-β1 (TGF-β1), collagen type Iα1, α-smooth muscle actin, and the macrophage markers Emr1, as well as the chemoattractant Ccl2, interleukin-1β (IL1β) and tumor necrosis factor-α (TNFα) were analyzed. Assessment of portal and systemic hemodynamics was performed using the colored microsphere technique. As expected, WD induced obesity and liver fibrosis as confirmed by Sirius Red and Oil Red O staining. The expression of the monocyte-macrophage markers, Emr1, Ccl2, IL1β and TNFα were increased during feeding of WD, indicating infiltration of macrophages into the liver, even though this increase was statistically not significant for the EGF module-containing mucin-like receptor (Emr1) mRNA expression levels. Of note, portal pressure increased with the duration of WD compared to animals that received a normal chow. Besides obesity, WD feeding increased systemic vascular resistance reflecting systemic endothelial and splanchnic vascular dysfunction. We conclude that transgenic TGR(mREN2)27 rats are a suitable model to investigate NAFLD development with liver fibrosis and portal hypertension. Tendency towards elevated expression of Emr1 is associated with macrophage activity point to a significant role of macrophages in NAFLD pathogenesis, probably due to a shift of the renin–angiotensin system towards a higher activation of the classical pathway. The hepatic injury induced by WD in TGR(mREN2)27 rats is suitable to evaluate different stages of fibrosis and portal hypertension in NAFLD with obesity.

Molecular and cellular research modalities for the study of liver pathologies have been tremendously improved over the recent decades. Advanced technologies offer novel opportunities to establish cell isolation techniques with excellent purity, paving the path for 2D and 3D microscopy and high-throughput assays (e.g., bulk or single-cell RNA sequencing). The use of stem cell and organoid research will help to decipher the pathophysiology of liver diseases and the interaction between various parenchymal and non-parenchymal liver cells. Furthermore, sophisticated animal models of liver disease allow for the in vivo assessment of fibrogenesis, portal hypertension and hepatocellular carcinoma (HCC) and for the preclinical testing of therapeutic strategies. The purpose of this review is to portray in detail novel in vitro and in vivo methods for the study of liver cell biology that had been presented at the workshop of the 8th meeting of the European Club for Liver Cell Biology (ECLCB-8) in October of 2018 in Bonn, Germany.

Introduction: Recent animal studies have shown that the alternate renin-angiotensin system (RAS) consisting of angiotensin-converting enzyme 2 (ACE2), angiotensin-(1–7) (Ang-(1–7)) and the Mas receptor is upregulated in cirrhosis and contributes to splanchnic vasodilatation and portal hypertension. To determine the potential relevance of these findings to human liver disease, we evaluated its expression and relationship to the patients’ clinical status in subjects with cirrhosis. Methods: Blood sampling from peripheral and central vascular beds was performed intra-operatively for cirrhotic patients at the time of liver transplantation (LT) or trans-jugular intra-hepatic portosystemic shunt (TIPS) procedures to measure angiotensin II (Ang II) and Ang-(1–7) peptide levels and ACE and ACE2 enzyme activity. Relevant clinical and hemodynamic data were recorded pre-operatively for all subjects and peripheral blood sampling was repeated 3 months or later post-operatively. Results: Ang-(1–-7) and ACE2 activity were up-regulated more than twofold in cirrhotic subjects both at the time of LT and TIPS and levels returned to comparable levels as control subjects post-transplantation. Ang-(1–7) levels correlated positively with the degree of liver disease severity, as measured by the model for an end-stage liver disease (MELD) and also with clinical parameters of pathological vasodilatation including cardiac output (CO). There were strong correlations found between the ACE2:ACE and the Ang-(1–7):Ang II ratio highlighting the inter-dependence of the alternate and classical arms of the RAS and thus their potential impact on vascular tone. Conclusions: In human cirrhosis, the alternate RAS is markedly upregulated and the activation of this system is associated strongly with features of the hyperdynamic circulation in advanced human cirrhosis.