[Primary sclerosing cholangitis-Diagnosis and treatment 2024]. / Primär sklerosierende Cholangitis ­ Diagnose und Therapie 2024.

The etiology of primary sclerosing cholangitis (PSC) remains unclear, which explains in part the lack of a causal treatment. The differential diagnostic distinction from the even rarer immunoglobulin 4 (IgG4)-associated cholangitis (IAC) is becoming increasingly more successful. Advances in the understanding of different clinical courses, improvements in noninvasive diagnostics through modern magnetic resonance imaging (MRI) and the introduction of liver elastography have led to the development of improved prognostic models. The evidence for recommendations on medicinal (e.g., ursodeoxycholic acid) or endoscopic treatment (e.g., balloon dilatation and/or stent insertion) for PSC is still low. In contrast, the long-term results of liver transplantation in PSC patients are constantly improving. Due to the lack of highly sensitive and specific screening methods the early recognition of cholangiocellular carcinoma (CCC) as the most important complication is rarely successful. The continuous improvement of endoscopic retrograde cholangiopancreatography (ERCP) and direct cholangioscopy in combination with molecular biological and fluorescence in situ hybridization (FISH) analyses of bile duct tissue samples are promising for refined diagnostics. Due to the significantly increased risk of colorectal cancer, an annual colonoscopy is recommended in the presence of inflammatory bowel disease. Improvement of the early diagnostics of PSC and successful testing of new treatment strategies raise hope for a continuous improvement in the medical support of these complex patients.

Evaluation of potential hepatic recompensation criteria in patients with PBC and decompensated cirrhosis.

BACKGROUND: Aetiological therapy improves liver function and may enable hepatic recompensation in decompensated cirrhosis. AIMS: We explored the potential for recompensation in patients with decompensated primary biliary cholangitis (PBC) - considering a biochemical response to ursodeoxycholic acid (UDCA) according to Paris-II criteria as a surrogate for successful aetiological treatment. METHODS: Patients with PBC were retrospectively included at the time of first decompensation. Recompensation was defined as (i) resolution of ascites and hepatic encephalopathy (HE) despite discontinuation of diuretic/HE therapy, (ii) absence of variceal bleeding and (iii) sustained liver function improvement. RESULTS: In total, 42 patients with PBC with decompensated cirrhosis (age: 63.5 [IQR: 51.9-69.2] years; 88.1% female; MELD-Na: 13.5 [IQR: 11.0-15.0]) were included and followed for 41.9 (IQR: 11.0-70.9) months after decompensation. Seven patients (16.7%) achieved recompensation. Lower MELD-Na (subdistribution hazard ratio [SHR]: 0.90; p = 0.047), bilirubin (SHR per mg/dL: 0.44; p = 0.005) and alkaline phosphatase (SHR per 10 U/L: 0.67; p = 0.001) at decompensation, as well as variceal bleeding as decompensating event (SHR: 4.37; p = 0.069), were linked to a higher probability of recompensation. Overall, 33 patients were treated with UDCA for ≥1 year and 12 (36%) achieved Paris-II response criteria. Recompensation occurred in 5/12 (41.7%) and in 2/21 (9.5%) patients with vs. without UDCA response at 1 year, respectively. Recompensation was linked to a numerically improved transplant-free survival (HR: 0.46; p = 0.335). Nonetheless, 4/7 recompensated patients presented with liver-related complications after developing hepatic malignancy and/or portal vein thrombosis and 2 eventually died. CONCLUSIONS: Patients with PBC and decompensated cirrhosis may achieve hepatic recompensation under UDCA therapy. However, since liver-related complications still occur after recompensation, patients should remain under close follow-up.

Antibiotics attenuate diet-induced nonalcoholic fatty liver disease without altering intestinal barrier dysfunction.

To date the role of the alterations of intestinal microbiota in the development of intestinal barrier dysfunction in settings of nonalcoholic fatty liver disease (NAFLD) has not been fully understood. Here, we assessed the effect of antibiotics on development of NAFLD and their impact on intestinal barrier dysfunction. Male C57BL/6J mice were either pair-fed a liquid control diet (C) or fat- and fructose-rich diet (FFr) +/- antibiotics (AB, ampicillin/vancomycin/metronidazole/gentamycin) for 7 weeks. Fasting blood glucose was determined and markers of liver damage, inflammation, intestinal barrier function, and microbiota composition were assessed. The development of hepatic steatosis with early signs of inflammation found in FFr-fed mice was significantly abolished in FFr+AB-fed mice. Also, while prevalence of bacteria in feces was not detectable and TLR4 ligand levels in portal plasma were at the level of controls in FFr+AB-fed mice, impairments of intestinal barrier function like an increased permeation of xylose and iNOS protein levels persisted to a similar extent in both FFr-fed groups irrespective of AB use. Exposure of everted small intestinal tissue sacs of naïve mice to fructose resulted in a significant increase in tissue permeability and loss of tight junction proteins, being not affected by the presence of AB, whereas the concomitant treatment of tissue sacs with the NOS inhibitor aminoguanidine attenuated these alterations. Taken together, our data suggest that intestinal barrier dysfunction in diet-induced NAFLD in mice may not be predominantly dependent on changes in intestinal microbiota but rather that fructose-induced alterations of intestinal NO-homeostasis might be critically involved.

Diagnosis of functional strictures in patients with primary sclerosing cholangitis using hepatobiliary contrast-enhanced MRI: a proof-of-concept study.

OBJECTIVES: PSC strictures are routinely diagnosed on T2-MRCP as dominant- (DS) or high-grade stricture (HGS). However, high inter-observer variability limits their utility. We introduce the "potential functional stricture" (PFS) on T1-weighted hepatobiliary-phase images of gadoxetic acid-enhanced MR cholangiography (T1-MRC) to assess inter-reader agreement on diagnosis, location, and prognostic value of PFS on T1-MRC vs. DS or HGS on T2-MRCP in PSC patients, using ERCP as the gold standard. METHODS: Six blinded readers independently reviewed 129 MRIs to diagnose and locate stricture, if present. DS/HGS was determined on T2-MRCP. On T1-MRC, PFS was diagnosed if no GA excretion was seen in the CBD, hilum or distal RHD, or LHD. If excretion was normal, "no functional stricture" (NFS) was diagnosed. T1-MRC diagnoses (NFS = 87; PFS = 42) were correlated with ERCP, clinical scores, labs, splenic volume, and clinical events. Statistical analyses included Kaplan-Meier curves and Cox regression. RESULTS: Interobserver agreement was almost perfect for NFS vs. PFS diagnosis, but fair to moderate for DS and HGS. Forty-four ERCPs in 129 patients (34.1%) were performed, 39 in PFS (92.9%), and, due to clinical suspicion, five in NFS (5.7%) patients. PFS and NFS diagnoses had 100% PPV and 100% NPV, respectively. Labs and clinical scores were significantly worse for PFS vs. NFS. PFS patients underwent more diagnostic and therapeutic ERCPs, experienced more clinical events, and reached significantly more endpoints (p < 0.001) than those with NFS. Multivariate analysis identified PFS as an independent risk factor for liver-related events. CONCLUSION: T1-MRC was superior to T2-MRCP for stricture diagnosis, stricture location, and prognostication. CLINICAL RELEVANCE STATEMENT: Because half of PSC patients will develop clinically-relevant strictures over the course of the disease, earlier more confident diagnosis and correct localization of functional stricture on gadoxetic acid-enhanced MRI may optimize management and improve prognostication. KEY POINTS: • There is no consensus regarding biliary stricture imaging features in PSC that have clinical relevance. • Twenty-minute T1-weighted MRC images correctly classified PSC patients with potential (PFS) vs with no functional stricture (NFS). • T1-MRC diagnoses may reduce the burden of diagnostic ERCPs.

A Xanthohumol-Rich Hop Extract Diminishes Endotoxin-Induced Activation of TLR4 Signaling in Human Peripheral Blood Mononuclear Cells: A Study in Healthy Women.

Infections with Gram-negative bacteria are still among the leading causes of infection-related deaths. Several studies suggest that the chalcone xanthohumol (XN) found in hop (Humulus lupulus) possesses anti-inflammatory effects. In a single-blinded, placebo controlled randomized cross-over design study we assessed if the oral intake of a single low dose of 0.125 mg of a XN derived through a XN-rich hop extract (75% XN) affects lipopolysaccharide (LPS)-induced immune responses in peripheral blood mononuclear cells (PBMCs) ex vivo in normal weight healthy women (n = 9) (clinicaltrials.gov: NCT04847193) and determined associated molecular mechanisms. LPS-stimulation of PBMCs isolated from participants 1 h after the intake of the placebo for 2 h resulted in a significant induction of pro-inflammatory cytokine release which was significantly attenuated when participants had consumed XN. The XN-dependent attenuation of proinflammatory cytokine release was less pronounced 6 h after the LPS stimulation while the release of sCD14 was significantly reduced at this timepoint. The LPS-dependent activation of hTLR4 transfected HEK293 cells was significantly and dose-dependently suppressed by the XN-rich hop extract which was attenuated when cells were co-challenged with sCD14. Taken together, our results suggest even a one-time intake of low doses of XN consumed in a XN-rich hop extract can suppress LPS-dependent stimulation of PBMCs and that this is related to the interaction of the hop compound with the CD14/TLR4 signaling cascade.

In vitro/in silico prediction of drug induced steatosis in relation to oral doses and blood concentrations by the Nile Red assay.

The accumulation of lipid droplets in hepatocytes is a key feature of drug-induced liver injury (DILI) and can be induced by a subset of hepatotoxic compounds. In the present study, we optimized and evaluated an in vitro technique based on the fluorescent dye Nile Red, further named Nile Red assay to quantify lipid droplets induced by the exposure to chemicals. The Nile Red assay and a cytotoxicity test (CTB assay) were then performed on cells exposed concentration-dependently to 60 different compounds. Of these, 31 were known to induce hepatotoxicity in humans, and 13 were reported to also cause steatosis. In order to compare in vivo relevant blood concentrations, pharmacokinetic models were established for all compounds to simulate the maximal blood concentrations (Cmax) at therapeutic doses. The results showed that several hepatotoxic compounds induced an increase in lipid droplets at sub-cytotoxic concentrations. To compare how well (1) the cytotoxicity test alone, (2) the Nile Red assay alone, and (3) the combination of the cytotoxicity test and the Nile Red assay (based on the lower EC10 of both assays) allow the differentiation between hepatotoxic and non-hepatotoxic compounds, a previously established performance metric, the Toxicity Separation Index (TSI) was calculated. In addition, the Toxicity Estimation Index (TEI) was calculated to determine how well blood concentrations that cause an increased DILI risk can be estimated for hepatotoxic compounds. Our findings indicate that the combination of both assays improved the TSI and TEI compared to each assay alone. In conclusion, the study demonstrates that inclusion of the Nile Red assay into in vitro test batteries may improve the prediction of DILI compounds.

Oral intake of xanthohumol attenuates lipoteichoic acid-induced inflammatory response in human PBMCs.

PURPOSE: The aim of the study was to determine if xanthohumol, a prenylated chalcone found in Hop (Humulus lupulus), has anti-inflammatory effects in healthy humans if applied in low doses achievable through dietary intake. METHODS: In a placebo-controlled single-blinded cross-over design study, 14 healthy young men and women either consumed a beverage containing 0.125 mg xanthohumol or a placebo. Peripheral blood mononuclear cells (PBMCs) were isolated before and 1 h after the intake of the beverages. Subsequently, PBMCs were stimulated with or without lipoteichoic acid (LTA) for 24 and 48 h. Concentrations of interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and soluble cluster of differentiation (sCD14) protein were determined in cell culture supernatant. Furthermore, hTLR2 transfected HEK293 cells were stimulated with LTA in the presence or absence of xanthohumol and sCD14. RESULTS: The stimulation of PBMCs with LTA for 24 and 48 h resulted in a significant induction of IL-1ß, IL-6, and sCD14 protein release in PBMCs of both, fasted subjects and subjects after the ingestion of the placebo. In contrast, after ingesting xanthohumol, LTA-dependent induction of IL-1ß, IL-6, and sCD14 protein release from PBMCs was not significantly higher than in unstimulated cells after 48 h. In hTLR2 transfected HEK293 cells xanthohumol significantly suppressed the LTA-dependent activation of cells, an effect attenuated when cells were co-incubated with sCD14. CONCLUSION: The results of our study suggest that an ingestion of low doses of xanthohumol can suppress the LTA-dependent stimulation of PBMCs through mechanisms involving the interaction of CD14 with TLR2. Study registered at ClinicalTrials.gov (NCT04847193, 22.03.2022).

Progressive cholestasis and associated sclerosing cholangitis are frequent complications of COVID-19 in patients with chronic liver disease.

BACKGROUND AND AIMS: Cholestasis is associated with disease severity and worse outcome in COVID-19. Cases of secondary sclerosing cholangitis (SSC) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been described. APPROACH AND RESULTS: Hospitalized patients with COVID-19 between 03/2020 and 07/2021 were included. Patients were stratified as having (i) no chronic liver disease (CLD), (ii) non-advanced CLD (non-ACLD), or (iii) advanced CLD (ACLD). Patients with CLD and non-COVID-19 pneumonia were matched to patients with CLD and COVID-19 as a control cohort. Liver chemistries before (Pre) and at first, second, and third blood withdrawal after SARS-CoV-2 infection (T1-T3) and at last available time point (last) were recorded. A total of 496 patients were included. In total, 13.1% (n = 65) had CLD (non-ACLD: 70.8%; ACLD: 29.2%); the predominant etiology was NAFLD/NASH (60.0%). COVID-19-related liver injury was more common among patients with CLD (24.6% vs. 10.6%; p = 0.001). After SARS-CoV-2 infection, patients with CLD exhibited progressive cholestasis with persistently increasing levels of alkaline phosphatase (Pre: 91.0 vs. T1: 121.0 vs. last: 175.0 U/L; p < 0.001) and gamma-glutamyl transferase (Pre: 95.0 vs. T1: 135.0 vs. last: 202.0 U/L; p = 0.001). A total of 23.1% of patients with CLD (n = 15/65) developed cholestatic liver failure (cholestasis plus bilirubin ≥6 mg/dl) during COVID-19, and 15.4% of patients (n = 10/65) developed SSC. SSC was significantly more frequent among patients with CLD and COVID-19 than in patients with CLD and non-COVID-19 pneumonia (p = 0.040). COVID-19-associated SSC occurred predominantly in patients with NAFLD/NASH and metabolic risk factors. A total of 26.3% (n = 5/19) of patients with ACLD experienced hepatic decompensation after SARS-CoV-2 infection. CONCLUSIONS: About 20% of patients with CLD develop progressive cholestasis after SARS-CoV-2 infection. Patients with NAFLD/NASH and metabolic risk factors are at particular risk for developing cholestatic liver failure and/or SSC after COVID-19.

Hepatocyte-specific deletion of adipose triglyceride lipase (adipose triglyceride lipase/patatin-like phospholipase domain containing 2) ameliorates dietary induced steatohepatitis in mice.

BACKGROUND AND AIMS: Increased fatty acid (FA) flux from adipose tissue to the liver contributes to the development of NAFLD. Because free FAs are key lipotoxic triggers accelerating disease progression, inhibiting adipose triglyceride lipase (ATGL)/patatin-like phospholipase domain containing 2 (PNPLA2), the main enzyme driving lipolysis, may attenuate steatohepatitis. APPROACH AND RESULTS: Hepatocyte-specific ATGL knockout (ATGL LKO) mice were challenged with methionine-choline-deficient (MCD) or high-fat high-carbohydrate (HFHC) diet. Serum biochemistry, hepatic lipid content and liver histology were assessed. Mechanistically, hepatic gene and protein expression of lipid metabolism, inflammation, fibrosis, apoptosis, and endoplasmic reticulum (ER) stress markers were investigated. DNA binding activity for peroxisome proliferator-activated receptor (PPAR) α and PPARδ was measured. After short hairpin RNA-mediated ATGL knockdown, HepG2 cells were treated with lipopolysaccharide (LPS) or oleic acid:palmitic acid 2:1 (OP21) to explore the direct role of ATGL in inflammation in vitro. On MCD and HFHC challenge, ATGL LKO mice showed reduced PPARα and increased PPARδ DNA binding activity when compared with challenged wild-type (WT) mice. Despite histologically and biochemically pronounced hepatic steatosis, dietary-challenged ATGL LKO mice showed lower hepatic inflammation, reflected by the reduced number of Galectin3/MAC-2 and myeloperoxidase-positive cells and low mRNA expression levels of inflammatory markers (such as IL-1ß and F4/80) when compared with WT mice. In line with this, protein levels of the ER stress markers protein kinase R-like endoplasmic reticulum kinase and inositol-requiring enzyme 1α were reduced in ATGL LKO mice fed with MCD diet. Accordingly, pretreatment of LPS-treated HepG2 cells with the PPARδ agonist GW0742 suppressed mRNA expression of inflammatory markers. Additionally, ATGL knockdown in HepG2 cells attenuated LPS/OP21-induced expression of proinflammatory cytokines and chemokines such as chemokine (C-X-C motif) ligand 5, chemokine (C-C motif) ligand (Ccl) 2, and Ccl5. CONCLUSIONS: Low hepatic lipolysis and increased PPARδ activity in ATGL/PNPLA2 deficiency may counteract hepatic inflammation and ER stress despite increased steatosis. Therefore, lowering hepatocyte lipolysis through ATGL inhibition represents a promising therapeutic strategy for the treatment of steatohepatitis.

Concentration of Gallbladder Phosphatidylcholine in Cholangiopathies: A Phosphorus-31 Magnetic Resonance Spectroscopy Pilot Study.

BACKGROUND: Biliary phosphatidylcholine (PtdC) concentration plays a role in the pathogenesis of bile duct diseases. In vivo phosphorus-31 magnetic resonance spectroscopy (31 P-MRS) at 7 T offers the possibility to assess this concentration noninvasively with high spectral resolution and signal intensity. PURPOSE: Comparison of PtdC levels of cholangiopathic patient groups to a control group using a measured T1 relaxation time of PtdC in healthy subjects. STUDY TYPE: Case control. SUBJECTS: Two patient groups with primary sclerosing cholangitis (PSC, 2f/3 m; age: 43 ± 7 years) and primary biliary cholangitis (PBC, 4f/2 m; age: 57 ± 6 years), and a healthy control group (CON, 2f/3 m; age: 38 ± 7 years). Ten healthy subjects for the assessment of the T1 relaxation time of PtdC. FIELD STRENGTH/SEQUENCE: A 3D phase-encoded pulse-acquire 31 P-MRSI sequence for PtdC quantification and a 1D image-selected in vivo 31 P spectroscopy for T1 estimation at 7 T, and a T2-weighted half-Fourier single-shot turbo spin echo MRI sequence for volumetry at 3 T. ASSESSMENT: Calculation of gallbladder volumes and PtdC concentration in groups using hepatic gamma-adenosine triphosphate signal as an internal reference and correction for insufficient relaxation of PtdC with a T1 value assessed in healthy subjects. STATISTICAL TESTS: Group comparison of PtdC content and gallbladder volumes of the PSC/PBC and CON group using Student's t-tests with a significance level of 5%. RESULTS: PtdC T1 value of 357 ± 85 msec in the gallbladder. Significant lower PtdC content for the PSC group, and for the female subgroup of the PBC group compared to the CON group (PSC/CON: 5.74 ± 0.73 mM vs. 9.64 ± 0.97 mM, PBC(f)/CON: 5.77 ± 1.44 mM vs. 9.64 ± 0.97 mM). Significant higher gallbladder volumes of the patient groups compared to the CON group (PSC/CON: 66.3 ± 15.8 mL vs. 20.9 ± 2.2 mL, PBC/CON: 49.8 ± 18.2 mL vs. 20.9 ± 2.2 mL). DATA CONCLUSION: This study demonstrated the application of a 31 P-MRSI protocol for the quantification of PtdC in the human gallbladder at 7 T. Observed differences in PtdC concentration suggest that this metabolite could serve as a biomarker for specific hepatobiliary disorders. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Distinct prognostic value of different portal hypertension-associated features in patients with primary biliary cholangitis.

BACKGROUND: Primary biliary cholangitis (PBC) may progress to cirrhosis and clinically significant portal hypertension (CSPH). This study assesses different features of CSPH and their distinct prognostic impact regarding decompensation and survival in patients with PBC. METHODS: Patients with PBC were identified during a database query of our digital patient reporting system. RESULTS: A total of 333 PBC patients (mean age 54.3 years, 86.8% females, median follow-up 5.8 years) were retrospectively assessed and 127 (38.1%) showed features of CSPH: 63 (18.9%) developed varices, 98 (29.4%) splenomegaly, 62 (18.6%) ascites and 20 (15.7%) experienced acute variceal bleeding. Splenomegaly, portosystemic collaterals and esophageal varices were associated with an increased 5-year (5Y) risk of decompensation (15.0%, 17.8% and 20.9%, respectively). Patients without advanced chronic liver disease (ACLD) had a similar 5Y-transplant free survival (TFS) (96.6%) compared to patients with compensated ACLD (cACLD) but without CSPH (96.9%). On the contrary, PBC patients with cACLD and CSPH (57.4%) or decompensated ACLD (dACLD) (36.4%) had significantly decreased 5Y survival rates. The combination of LSM < 15 kPa and platelets ≥ 150G/L indicated a negligible risk for decompensation (5Y 0.0%) and for mortality (5Y 0.0%). Overall, 44 (13.2%) patients died, with 18 (40.9%) deaths attributed to CSPH-related complications. CONCLUSION: In PBC, features of CSPH may occur early and indicate an increased risk for subsequent decompensation and mortality. Hence, regular screening and on-time treatment for CSPH is crucial. Combining LSM and platelets serves as a valuable preliminary assessment, as LSM < 15 kPa and platelets ≥ 150G/L indicate an excellent long-term outcome.

Spatio-Temporal Multiscale Analysis of Western Diet-Fed Mice Reveals a Translationally Relevant Sequence of Events during NAFLD Progression.

Mouse models of non-alcoholic fatty liver disease (NAFLD) are required to define therapeutic targets, but detailed time-resolved studies to establish a sequence of events are lacking. Here, we fed male C57Bl/6N mice a Western or standard diet over 48 weeks. Multiscale time-resolved characterization was performed using RNA-seq, histopathology, immunohistochemistry, intravital imaging, and blood chemistry; the results were compared to human disease. Acetaminophen toxicity and ammonia metabolism were additionally analyzed as functional readouts. We identified a sequence of eight key events: formation of lipid droplets; inflammatory foci; lipogranulomas; zonal reorganization; cell death and replacement proliferation; ductular reaction; fibrogenesis; and hepatocellular cancer. Functional changes included resistance to acetaminophen and altered nitrogen metabolism. The transcriptomic landscape was characterized by two large clusters of monotonously increasing or decreasing genes, and a smaller number of 'rest-and-jump genes' that initially remained unaltered but became differentially expressed only at week 12 or later. Approximately 30% of the genes altered in human NAFLD are also altered in the present mouse model and an increasing overlap with genes altered in human HCC occurred at weeks 30-48. In conclusion, the observed sequence of events recapitulates many features of human disease and offers a basis for the identification of therapeutic targets.

24-Norursodeoxycholic acid reshapes immunometabolism in CD8+ T cells and alleviates hepatic inflammation.

BACKGROUND & AIMS: 24-Norursodeoxycholic acid (NorUDCA) is a novel therapeutic bile acid used to treat immune-mediated cholestatic liver diseases, such as primary sclerosing cholangitis (PSC), where dysregulated T cells including CD8+ T cells contribute to hepatobiliary immunopathology. We hypothesized that NorUDCA may directly modulate CD8+ T cell function thus contributing to its therapeutic efficacy. METHODS: NorUDCA's immunomodulatory effects were first studied in Mdr2-/- mice, as a cholestatic model of PSC. To differentiate NorUDCA's immunomodulatory effects on CD8+ T cell function from its anticholestatic actions, we also used a non-cholestatic model of hepatic injury induced by an excessive CD8+ T cell immune response upon acute non-cytolytic lymphocytic choriomeningitis virus (LCMV) infection. Studies included molecular and biochemical approaches, flow cytometry and metabolic assays in murine CD8+ T cells in vitro. Mass spectrometry was used to identify potential CD8+ T cell targets modulated by NorUDCA. The signaling effects of NorUDCA observed in murine cells were validated in circulating T cells from patients with PSC. RESULTS: NorUDCA demonstrated immunomodulatory effects by reducing hepatic innate and adaptive immune cells, including CD8+ T cells in the Mdr2-/- model. In the non-cholestatic model of CD8+ T cell-driven immunopathology induced by acute LCMV infection, NorUDCA ameliorated hepatic injury and systemic inflammation. Mechanistically, NorUDCA demonstrated strong immunomodulatory efficacy in CD8+ T cells affecting lymphoblastogenesis, expansion, glycolysis and mTORC1 signaling. Mass spectrometry identified that NorUDCA regulates CD8+ T cells by targeting mTORC1. NorUDCA's impact on mTORC1 signaling was further confirmed in circulating PSC CD8+ T cells. CONCLUSIONS: NorUDCA has a direct modulatory impact on CD8+ T cells and attenuates excessive CD8+ T cell-driven hepatic immunopathology. These findings are relevant for treatment of immune-mediated liver diseases such as PSC. LAY SUMMARY: Elucidating the mechanisms by which 24-norursodeoxycholic acid (NorUDCA) works for the treatment of immune-mediated liver diseases, such as primary sclerosing cholangitis, is of considerable clinical interest. Herein, we uncovered an unrecognized property of NorUDCA in the immunometabolic regulation of CD8+ T cells, which has therapeutic relevance for immune-mediated liver diseases, including PSC.

Combined effects of PNPLA3, TM6SF2 and HSD17B13 variants on severity of biopsy-proven non-alcoholic fatty liver disease.

OBJECTIVE: Several single-nucleotide polymorphisms have been identified to be disadvantageous or protective in regard to disease severity in patients with non-alcoholic fatty liver disease (NAFLD). However, it is unclear, whether including genetic risk factor(s) either alone or combined into risk stratification algorithms for NAFLD actually provides incremental benefit over clinical risk factors. DESIGN: Patients with biopsy-proven NAFLD were genotyped for the PNPLA3-rs738409(minor allele:G), TM6SF2-rs58542926(minor allele:T) and HSD17B13- rs72613567 (minor allele:TA) variants. The NAFLD activity score (NAS) and fibrosis stage (F0-F4) were used to grade and stage all liver biopsy samples. Patients from seven centers throughout Central Europe were considered for the study. RESULTS: 703 patients were included: NAS ≥ 5:173(24.6%); Fibrosis: F3-4:81(11.5%). PNPLA3 G/G genotype was associated with a NAS ≥ 5(aOR 2.23, p = 0.007) and advanced fibrosis (aOR-3.48, p < 0.001).TM6SF2 T/- was associated with advanced fibrosis (aOR 1.99, p = 0.023). HSD17B13 TA/- was associated with a lower probability of NAS ≥ 5(TA/T: aOR 0.65, p = 0.041, TA/TA: aOR 0.40, p = 0.033). Regarding the predictive capability for NAS ≥ 5, well-known risk factors (age, sex, BMI, diabetes, and ALT; baseline model) had an AUC of 0.758, Addition of PNPLA3(AUC 0.766), HSB17B13(AUC 0.766), and their combination(AUC 0.775), but not of TM6SF2(AUC 0.762), resulted in a higher diagnostic accuracy of the model. Addition of genetic markers for the prediction of advanced fibrosis (baseline model: age, sex, BMI, diabetes: AUC 0.777) resulted in a higher AUC if PNPLA3(AUC 0.789), and TM6SF2(AUC 0.786) but not if HSD17B13(0.777) were added. CONCLUSION: In biopsy-proven NAFLD, PNPLA3 G/-, TM6SF2 T/- and HSD17B13 TA/- carriage are associated with severity of NAFLD. Incorporating these genetic risk factors into risk stratification models might improve their predictive accuracy for severity of NAFLD and/or advanced fibrosis on liver biopsy.

Prevalence of anti-Hepatitis E antibodies and impact on disease severity in non-alcoholic fatty liver disease.

AIM: In most immune-competent individuals, hepatitis E (HEV) infections appear silent. It is unclear whether past HEV infections deteriorate disease severity in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: Patients with biopsy-proven NAFLD and data on anti-HEV immunoglobulin M (HEV-IgM) and anti-HEV IgG antibodies (HEV-IgG) were included. The NAFLD activity score (NAS) was used to grade and stage all liver biopsy samples. The HEV-IgG prevalence was compared to a healthy cohort of 997 subjects. RESULTS: One hundred sixty-seven patients with NAFLD were included with the following characteristics: age, 50 ± 13 years; NAS ≤4, 89 (53.3%); NAS 5-8, 78 (46.7%); cirrhosis, 16 (9.6%). Two patients (1.2%) were HEV-IgM-positive, however HEV polymerase chain reaction remained negative and no signs of acute hepatitis were seen. Forty-four patients (26.3%) were HEV-IgG-positive and they were significantly older (55 ± 10 years vs. 48 ± 13 years, P < 0.001) and predominantly men (31 [70.5%] vs.13 [29.5%], P = 0.022). Distribution across NAS (P = 0.610) was not different. However, HEV-IgG-positive patients were significantly more often found with cirrhosis (8 [18.2%] vs. 8 [6.5%], P = 0.024) and liver stiffness values >10 kPa (14 [58.2%] vs. 29 [43.3%], P = 0.026). Multivariable analyses revealed age (odds ratio [OR], 1.054 [1.022-1.086]) and male sex (OR 2.77 [1.27-6.04]) associated with HEV-IgG positivity. Presence of diabetes (OR 3.86 [1.18-12.59]), higher aspartate aminotransferase levels (OR, 1.02 [1.006-1.033]), and HEV-IgG seropositivity (OR 3.52 [1.11-11.13]) were independently linked to cirrhosis. Finally, HEV-IgG positivity was not independently associated with NAFLD patients in a case-control study including healthy subjects. CONCLUSIONS: Prevalence of anti-HEV-IgG antibodies in patients with NAFLD is linked to age and male sex. Furthermore, previous HEV infection was an independent risk factor for cirrhosis. Whether this finding is causal or solely associative is unclear and should be elucidated in future studies.

Open-label phase II study evaluating safety and efficacy of the non-steroidal farnesoid X receptor agonist PX-104 in non-alcoholic fatty liver disease.

BACKGROUND: The PX-104 is an oral non-steroidal agonist for the farnesoid X receptor (FXR), a key regulator of bile acid (BA), glucose and lipid homeostasis. AIMS AND METHODS: This single center, proof of concept study evaluated the efficacy, safety and tolerability of PX-104 in non-diabetic NAFLD patients. 12 individuals were treated daily with 5 mg of PX-104 orally for 4 weeks. Serum liver enzymes, insulin sensitivity by clamp like index (CLIX) and hepatic fat by proton 1H­MRS, MRI-PDFF and CAP were assessed. Hepatic energy metabolism and Kupffer cell function were evaluated by phosphorus 31P­MRS and superparamagnetic iron oxide MRI (SPIO-MRI). Other readouts included serum lipids and markers of BA metabolism/signaling besides fecal microbiome and BA analysis. RESULTS: A significant decrease in ALT (p = 0.027; 1­tailed) and GGT (p = 0.019) was observed, without changes in serum alkaline phosphatase or serum lipids. Insulin sensitivity improved in 92% of patients (p = 0.02). However, hepatic steatosis measured by PDFF-MRI, 1H­MRS and CAP besides extended serum lipoprotein and BA profiles did not change. NADPH/γATP ratios at 31P­MRS significantly decreased (p = 0.022) possibly reflecting reduced hepatic inflammatory stress, but SPIO-MRI remained unchanged. Reduced preponderance of Coriobacteriaceae (p = 0.036) correlated with a relative reduction of total fecal BAs. There were no serious adverse events but short intervals of cardiac arrhythmia recorded in 2 patients led to termination of the study. CONCLUSION: The non-steroidal FXR agonist PX-104 improved insulin sensitivity and liver enzymes after 4 weeks of treatment in non-diabetic NAFLD patients. Changes in fecal BAs and gut microbiota deserve more extensive investigations.

In Vivo 1 H MR Spectroscopy of Biliary Components of Human Gallbladder at 7T.

BACKGROUND: Previous in vivo proton MR spectroscopy (MRS) studies have demonstrated the possibility of quantifying amide groups of conjugated bile acids (NHCBA), olefinic lipids and cholesterol (OLC), choline-containing phospholipids (CCPLs), taurine and glycine conjugated bile acids (TCBA, GCBA), methylene group of lipids (ML), and methyl groups of bile acids, lipids, and cholesterol (BALC1.0, BALC0.9, and TBAC) in the gallbladder, which may be useful for the study of cholestatic diseases and cholangiopathies. However, these studies were performed at 1.5T and 3T, and higher magnetic fields may offer improved spectral resolution and signal intensity. PURPOSE: To develop a method for gallbladder MRS at 7T. STUDY TYPE: Retrospective, technical development. POPULATION: Ten healthy subjects (five males and five females), two patients with primary biliary cholangitis (PBC) (one male and one female), and one patient with primary sclerosing cholangitis (PSC) (female). FIELD STRENGTH/SEQUENCE: Free-breathing single-voxel MRS with a modified stimulated echo acquisition mode (STEAM) sequence at 7T. ASSESSMENT: Postprocessing was based on the T2 relaxation of water in the gallbladder and in the liver. Concentrations of biliary components were calculated using water signal. All data were corrected for T2 relaxation times measured in healthy subjects. STATISTICAL TESTS: The range of T2 relaxation time and concentration per bile component, and the resulting mean and standard deviation, were calculated. RESULTS: The concentrations of gallbladder components in healthy subjects were: NHCBA: 93 ± 66 mM, OLC: 154 ± 124 mM, CCPL: 42 ± 17 mM, TCBA: 48 ± 35 mM, GCBA: 67 ± 32 mM, ML: 740 ± 391 mM, BALC1.0: 175 ± 92 mM, BALC0.9: 260 ± 138 mM, and TBAC: 153 ± 90 mM. Mean concentrations of all bile components were found to be lower in patients. DATA CONCLUSION: This work provides a protocol for designing future MRS investigations of the bile system in vivo. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY STAGE: 1.

Variants in ABCB4 (MDR3) across the spectrum of cholestatic liver diseases in adults.

The ATP binding cassette subfamily B member 4 (ABCB4) gene on chromosome 7 encodes the ABCB4 protein (alias multidrug resistance protein 3 [MDR3]), a P-glycoprotein in the canalicular membrane of the hepatocytes that acts as a translocator of phospholipids into bile. Several variants in ABCB4 have been shown to cause ABCB4 deficiency, accounting for a disease spectrum ranging from progressive familial cholestasis type 3 to less severe conditions like low phospholipid-associated cholelithiasis, intrahepatic cholestasis of pregnancy or drug-induced liver injury. Furthermore, whole genome sequencing has shown that ABCB4 variants are associated with an increased incidence of gallstone disease, gallbladder and bile duct carcinoma, liver cirrhosis or elevated liver function tests. Diagnosis of ABCB4 deficiency-related diseases is based on clinical presentation, serum biomarkers, imaging techniques, liver histology and genetic testing. Nevertheless, the clinical presentation can vary widely and clear genotype-phenotype correlations are currently lacking. Ursodeoxycholic acid is the most commonly used medical treatment, but its efficacy has yet to be proven in large controlled clinical studies. Future pharmacological options may include stimulation/restoration of residual function by chaperones (e.g. 4-phenyl butyric acid, curcumin) or induction of ABCB4 transcription by FXR (farnesoid X receptor) agonists or PPARα (peroxisome proliferator-activated receptor-α)-ligands/fibrates. Orthotopic liver transplantation remains the last and often only therapeutic option in cirrhotic patients with end-stage liver disease or patients with intractable pruritus.