PPAR-Mediated Bile Acid Glucuronidation: Therapeutic Targets for the Treatment of Cholestatic Liver Diseases.

Cholestatic liver diseases, including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), result from an impairment of bile flow that leads to the hepatic retention of bile acids, causing liver injury. Until recently, the only approved treatments for PBC were ursodeoxycholic acid (UDCA) and obeticholic acid (OCA). While these therapies slow the progression of PBC in the early stage of the disease, approximately 40% of patients respond incompletely to UDCA, and advanced cases do not respond. UDCA does not improve survival in patients with PSC, and patients often have dose-limiting pruritus reactions to OCA. Left untreated, these diseases can progress to fibrosis and cirrhosis, resulting in liver failure and the need for transplantation. These shortcomings emphasize the urgent need for alternative treatment strategies. Recently, nuclear hormone receptors have been explored as pharmacological targets for adjunct therapy because they regulate enzymes involved in bile acid metabolism and detoxification. In particular, the peroxisome proliferator-activated receptor (PPAR) has emerged as a therapeutic target for patients with PBC or PSC who experience an incomplete response to UDCA. PPARα is predominantly expressed in the liver, and it plays an essential role in the regulation of cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, both of which are critical enzyme families involved in the regulation of bile acid metabolism and glucuronidation, respectively. Importantly, PPARα agonists, e.g., fenofibrate, have shown therapeutic benefits in reducing elevated markers of cholestasis in patients with PBC and PSC, and elafibranor, the first PPAR (dual α, ß/δ) agonist, has been FDA-approved for the second-line treatment of PBC. Additionally, newer PPAR agonists that target various PPAR isoforms (ß/δ, γ) are under development as an adjunct therapy for PBC or PSC, although their impact on glucuronidation pathways are less characterized. This review will focus on PPAR-mediated bile acid glucuronidation as a therapeutic pathway to improve outcomes for patients with PBC and PSC.

Serologic extracellular matrix remodeling markers are related to fibrosis stage and prognosis in a phase 2b trial of simtuzumab in patients with primary sclerosing cholangitis.

BACKGROUND: Novel noninvasive predictors of disease severity and prognosis in primary sclerosing cholangitis (PSC) are needed. This study evaluated the ability of extracellular matrix remodeling markers to diagnose fibrosis stage and predict PSC-related fibrosis progression and clinical events. METHODS: Liver histology and serum markers of collagen formation (propeptide of type III collagen [Pro-C3], propeptide of type IV collagen, propeptide of type V collagen), collagen degradation (type III collagen matrix metalloproteinase degradation product and type IV collagen matrix metalloproteinase degradation product), and fibrosis (enhanced liver fibrosis [ELF] score and its components [metalloproteinase-1, type III procollagen, hyaluronic acid]) were assessed in samples from baseline to week 96 in patients with PSC enrolled in a study evaluating simtuzumab (NCT01672853). Diagnostic performance for advanced fibrosis (Ishak stages 3-6) and cirrhosis (Ishak stages 5-6) was evaluated by logistic regression and AUROC. Prognostic performance for PSC-related clinical events and fibrosis progression was assessed by AUROC and Wilcoxon rank-sum test. RESULTS: Among 234 patients, 51% had advanced fibrosis and 11% had cirrhosis at baseline. Baseline Pro-C3 and ELF score and its components provided moderate diagnostic ability for discrimination of advanced fibrosis (AUROC 0.73-0.78) and cirrhosis (AUROC 0.73-0.81). Baseline Pro-C3, ELF score, and type III procollagen provided a moderate prognosis for PSC-related clinical events (AUROC 0.70-0.71). Among patients without cirrhosis at baseline, median changes in Pro-C3 and ELF score to week 96 were higher in those with than without progression to cirrhosis (both p < 0.001). CONCLUSIONS: Pro-C3 correlated with fibrosis stage, and Pro-C3 and ELF score provided discrimination of advanced fibrosis and cirrhosis and predicted PSC-related events and fibrosis progression. The results support the clinical utility of Pro-C3 and ELF score for staging and as prognostic markers in PSC.

Network proximity analysis as a theoretical model for identifying potential novel therapies in primary sclerosing cholangitis.

Primary Sclerosing Cholangitis (PSC) is a progressive cholestatic liver disease with no licensed therapies. Previous Genome Wide Association Studies (GWAS) have identified genes that correlate significantly with PSC, and these were identified by systematic review. Here we use novel Network Proximity Analysis (NPA) methods to identify already licensed candidate drugs that may have an effect on the genetically coded aspects of PSC pathophysiology.Over 2000 agents were identified as significantly linked to genes implicated in PSC by this method. The most significant results include previously researched agents such as metronidazole, as well as biological agents such as basiliximab, abatacept and belatacept. This in silico analysis could potentially serve as a basis for developing novel clinical trials in this rare disease.

Immune-related adverse event-associated sclerosing cholangitis due to immune checkpoint inhibitors: imaging findings and treatments.

OBJECTIVES: Immune-related adverse event-sclerosing cholangitis caused by treatment with immune checkpoint inhibitors is rare, and the diagnostic criteria and treatment strategy remain unclear. In this study, we confirmed the clinicopathological features of immune-related adverse event-sclerosing cholangitis and clarified its diagnosis and appropriate management. METHODS: We retrospectively evaluated 10 patients diagnosed with immune-related adverse event-sclerosing cholangitis and identified by electronic database searches. RESULTS: Blood tests revealed liver dysfunction with a predominance of biliary tract enzymes in all patients; however, jaundice was present in only one patient. Contrast-enhanced computed tomography revealed diffuse hypertrophy of the extrahepatic bile duct wall as the most frequent finding; however, endoscopic retrograde cholangiopancreatography showed various imaging features, such as the pruned-tree appearance of intrahepatic bile ducts, in all patients. Transpapillary bile duct biopsy showed inflammatory cell infiltration using immunostaining, with a predominance of cluster of differentiation 8-positive T cells in 63% of the cases. Initial steroid therapy was effective in two cases. Mycophenolate mofetil and tacrolimus were used in steroid-refractory cases. Although six patients showed improvements, all of the remaining patients died owing to immune-related adverse event-sclerosing cholangitis. CONCLUSIONS: Various bile duct imaging findings of immune-related adverse event-sclerosing cholangitis were revealed; transpapillary bile duct biopsy may be useful in the diagnosis of immune-related adverse event-sclerosing cholangitis. Despite the combination of multiple immunosuppressive agents, prognosis of immune-related adverse event-sclerosing cholangitis remains poor. Longer follow-up and larger clinical studies are necessary to establish its treatment strategy.

Navigating the liver landscape: upcoming pharmacotherapies for primary sclerosing cholangitis.

INTRODUCTION: Primary sclerosing cholangitis (PSC) is a bile duct disorder characterized by ductular reaction, hepatic inflammation, and liver fibrosis. The pathogenesis of PSC is still undefined, and treatment options for patients are limited. Previous clinical trials evaluated drug candidates targeting various cellular functions and pathways, such as bile acid signaling and absorption, gut bacteria and permeability, and lipid metabolisms. However, most of phase III clinical trials for PSC were disappointing, except vancomycin therapy, and there are still no established medications for PSC with efficacy and safety confirmed by phase IV clinical trials. AREAS COVERED: This review summarizes the currently ongoing or completed clinical studies for PSC, which are phase II or further, and discusses therapeutic targets and strategies, limitations, and future directions and possibilities of PSC treatments. A literature search was conducted in PubMed and ClinicalTrials.gov utilizing the combination of the searched term 'primary sclerosing cholangitis' with other keywords, such as 'clinical trials,' 'antibiotics,' or drug names. Clinical trials at phase II or further were included for consideration. EXPERT OPINION: Only vancomycin demonstrated promising therapeutic effects in the phase III clinical trial. Other drug candidates showed futility or inconsistent results, and the search for novel PSC treatments is still ongoing.

Patient-focused drug development in primary sclerosing cholangitis: Insights on patient priorities and involvement in clinical trials.

BACKGROUND: According to the new AASLD Practice Guidance, all patients with primary sclerosing cholangitis (PSC) should be considered for participation in clinical trials. However, PSC's rarity has posed challenges to characterizing patient interest in trial participation and identifying predictors of patient willingness to participate in drug trials. METHODS: PSC Partners Seeking a Cure developed the "Our Voices" survey to inform the development of the Externally-Led Patient-Focused Drug Development Forum, an FDA initiative to capture patient experiences and perspectives on drug development. RESULTS: Of 797 survey respondents from over 30 countries, 536 (67%) identified slowing disease progression as the most important outcome. Eighty-nine percent identified their hepatologist/gastroenterologist as someone they would approach for advice about trials. Although 61% reported being willing to participate in drug trials, only 26% had ever been asked to participate. Notable barriers to trial involvement included unknown long-term risks (71%), long travel times to the study center (32%), and a liver biopsy requirement (27%). On multivariable logistic regression, pruritus (OR 1.62, 95% CI: 1.09-2.40, p = 0.017) was positively associated with willingness to participate in disease-modifying therapy trials, while jaundice (OR 0.34, 95% CI: 0.19-0.61, p < 0.001) and inflammatory bowel disease (OR 0.64, 95% CI: 0.42-0.98, p = 0.038) were negatively associated. Pruritus (OR 2.25, 95% CI: 1.50-3.39, p < 0.001) was also independently associated with willingness to participate in symptom treatment trials. CONCLUSIONS: Most patients with PSC report interest in participating in clinical trials, but few have been asked to participate. Referral of patients with PSC by their hepatologist/gastroenterologist to clinical trials and patient education on trial participation are vital to closing the gap between trial interest and participation. Pruritus may serve as a key indicator of patient interest in trial participation.

Pneumocystis jirovecii Pneumonia Complicating Use of Upadacitinib in a Patient With Ulcerative Colitis and Primary Sclerosing Cholangitis: A Case Report.

Pneumocystis jirovecii is a ubiquitous, unicellular fungus that can cause pneumonia (PJP) in immunosuppressed individuals. We report the first case of PJP complicating upadacitinib use for ulcerative colitis. This report is of clinical relevance given the widespread uptake of JAK inhibition.

Vascular adhesion protein-1 blockade in primary sclerosing cholangitis: Open-label, multicenter, single-arm, phase II trial.

BACKGROUND: Primary sclerosing cholangitis is a progressive inflammatory liver disease characterized by biliary and liver fibrosis. Vascular adhesion protein-1 (VAP-1) is important in the inflammatory process driving liver fibrosis. We evaluated the safety and efficacy of VAP-1 blockade with a monoclonal antibody (timolumab, BTT1023) in patients with primary sclerosing cholangitis. METHODS: BUTEO was a prospective, single-arm, open-label, multicenter, phase II trial, conducted in 6 centers in the United Kingdom. Patients with primary sclerosing cholangitis aged 18-75 years had an alkaline phosphatase value of >1.5 times the upper limit of normal. The dose-confirmatory stage aimed to confirm the safety of timolumab through the incidence of dose-limiting toxicity and sufficient trough levels of circulating antibody to block VAP-1 function. The primary outcome of the dose-expansion portion of the trial was patient's response to timolumab at day 99, as measured by a reduction in serum alkaline phosphatase by 25% or more from baseline to day 99. RESULTS: Twenty-three patients were recruited: 7 into the initial dose-confirmatory stage and a further 16 into an expansion stage. Timolumab (8 mg/kg) was confirmed to be safe for the duration of administration with sufficient circulating levels. Only 2 of the 18 evaluable patients (11.1%) achieved a reduction in alkaline phosphatase levels of 25% or more, and both the proportion of circulating inflammatory cell populations and biomarkers of fibrosis remained unchanged from baseline. CONCLUSIONS: The BUTEO trial confirmed 8 mg/kg timolumab had no short-term safety signals and resulted in sufficient circulating levels of VAP-1 blocking timolumab. However, the trial was stopped after an interim assessment due to a lack of efficacy as determined by no significant change in serum liver tests.

Oral vancomycin is associated with improved inflammatory bowel disease clinical outcomes in primary sclerosing cholangitis-associated inflammatory bowel disease (PSC-IBD): A matched analysis from the Paediatric PSC Consortium.

BACKGROUND: Data on oral vancomycin for primary sclerosing cholangitis (PSC)-associated inflammatory bowel disease (IBD) are limited. AIMS: Using data from the Paediatric PSC Consortium, to examine the effect of vancomycin on IBD activity. METHODS: In this retrospective multi-centre cohort study, we matched vancomycin-treated and untreated patients (1:3) based on IBD duration at the time of primary outcome assessment. The primary outcome was Physician Global Assessment (PGA) of IBD clinical activity after 1 year (±6 months) of vancomycin. We used generalised estimating equations (GEE) to examine the association between vancomycin and PGA remission, adjusting for IBD type, severity and medication exposures. Secondary outcomes included serum labs and endoscopic remission (global rating of no activity) among those with available data and also analysed with GEE. RESULTS: 113 PSC-IBD patients received vancomycin (median age 12.7 years, 63% male). The matched cohort included 70 vancomycin-treated and 210 untreated patients. Vancomycin was associated with greater odds of IBD clinical remission (odds ratio [OR] 3.52, 95% CI 1.97-6.31; adjusted OR [aOR] 5.24, 95% CI 2.68-10.22). Benefit was maintained in sensitivity analyses restricted to non-transplanted patients and those with baseline moderate-severe PGA. Vancomycin was associated with increased odds of endoscopic remission (aOR 2.76, 95% CI 1.002-7.62; N = 101 with data), and with lower CRP (p = 0.03) and higher haemoglobin and albumin (both p < 0.01). CONCLUSION: Vancomycin was associated with greater odds of IBD clinical and endoscopic remission. Additional, preferably randomised, controlled studies are needed to characterise efficacy using objective markers of mucosal inflammation, and to examine safety and define optimal dosing.

Novel preclinical developments of the primary sclerosing cholangitis treatment landscape.

INTRODUCTION: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease associated with inflammation, fibrosis, and destruction of intra- and extrahepatic bile ducts. Despite substantial recent advances in our understanding of PSC, the only proven treatment of PSC is liver transplantation. There is an urgent unmet need to find medical therapies for this disorder. AREAS COVERED: Multiple drugs are currently under evaluation as therapeutic options for this disease. This article summarizes the literature on the various novel therapeutic options that have been investigated and are currently under development for the treatment of PSC. EXPERT OPINION: In the next decade, more than one drug will likely be approved for the treatment of the disease, and we will be looking at combination therapies for the optimal management of the disease.

A protective effect of inflammatory bowel disease on the severity of sclerosing cholangitis.

Background: Primary sclerosing cholangitis (PSC) is a chronic liver disease marked by inflammation of the bile ducts and results in the development of strictures and fibrosis. A robust clinical correlation exists between PSC and inflammatory bowel disease (IBD). At present, published data are controversial, and it is yet unclear whether IBD drives or attenuates PSC. Methods: Mdr2-deficient mice or DDC-fed mice were used as experimental models for sclerosing cholangitis. Additionally, colitis was induced in mice with experimental sclerosing cholangitis, either through infection with Citrobacter rodentium or by feeding with DSS. Lastly, fibrosis levels were determined through FibroScan analysis in people with PSC and PSC-IBD. Results: Using two distinct experimental models of colitis and two models of sclerosing cholangitis, we found that colitis does not aggravate liver pathology, but rather reduces liver inflammation and liver fibrosis. Likewise, people with PSC-IBD have decreased liver fibrosis compared to those with PSC alone. Conclusions: We found evidence that intestinal inflammation attenuates liver pathology. This study serves as a basis for further research on the pathogenesis of PSC and PSC-IBD, as well as the molecular mechanism responsible for the protective effect of IBD on PSC development. This study could lead to the discovery of novel therapeutic targets for PSC.

An atypical case of isolated immunoglobulin G4-related sclerosing cholangitis with a cholangiogram resembling primary sclerosing cholangitis.

An asymptomatic 77-year-old man with intrahepatic bile duct dilation was referred to our hospital. Cholangiography revealed alternations between strictures and dilated segments from the right and left hepatic ducts to the lower bile ducts, with findings of a pruned tree, beaded, shaggy appearance, and diverticulum-like outpouching. Histopathology revealed abundant immunoglobulin G4 (IgG4)-positive plasma cells (> 10 per high-power field) with an IgG4/IgG-positive cell ratio of 40-50%. After 2 weeks of steroid therapy, the cholangiography markedly improved. Because the cholangiographic findings resembled those of primary sclerosing cholangitis, steroid therapy proved useful in differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis.

Evaluation of autoimmune liver disease natural history in patients referred to Middle East Liver Diseases (MELD) center.

BACKGROUND: Autoimmune liver diseases (AILD) are increasing and common forms of chronic liver disease (CLD) with different clinical responses and characteristics which can result in cirrhosis. This study aimed to investigate the natural history and characteristics of AILD in an Iranian population. METHODS: Patients with AILD [Autoimmune Hepatitis (AIH), Primary Biliary Cholangitis (PBC), Primary Sclerosing Cholangitis (PSC) and Overlap Syndrome (OS)] referred to Middle East Liver Diseases (MELD) center, Tehran, Iran, between January 2002 and December 2022 were included in this retrospective cohort study. The main features of natural history (the trends of liver functional tests (LFT), Auto-Antibodies, response to treatment and cirrhotic status) along with demographic data were studied. RESULTS: Two hundred sixty-five patients (160 (60.4%) AIH, 37 (14.0%) PBC, 20 (7.5%) PSC, 48 (18.1%) overlap syndrome) with a median follow-up time of 5 years (IQR 4 to 8 years) were included. Baseline laboratory tests revealed that patients with AIH exhibit elevated transaminase levels. However, patients suffering from PBC and PSC displayed increased alkaline phosphatase levels. Conversely, in overlap syndrome patients, both transaminases and alkaline phosphatase were observed at high levels. Autoantibodies represented themselves as important diagnostic markers for the AIH and PBC but not for PSC. The complete response occurred in 112 (70%) of and 28 (58.4%) patients with AIH and overlap syndrome respectively and 21 patients 11 (6.9%) of AIH and 10 (20.8%) of overlap syndrome) were non-responders. Other patients in these two categories were considered as insufficient responders. On the other side, 32 (91.9%) and 8 (40%) of patients with PBC and PSC biochemically responded to Ursodeoxycholic Acid (UDCA). Unpredictably, cirrhosis regression was observed in some AIH and PBC patients. CONCLUSION: Appropriate medication management for AILD patients may leads to regression from cirrhosis and improvement of manifestations; while discontinuation of medication may cause relapses. However, patient suffering from PSC showed limited response to treatment.

Efficacy and safety of biologics in primary sclerosing cholangitis with inflammatory bowel disease: A systematic review and meta-analysis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is an immune-mediated, chronic cholestatic liver disease. Currently, liver transplantation is the only established life-saving treatment. Several studies have evaluated the effect of different biologic therapies on PSC with inconclusive findings. We conducted a systematic review and meta-analysis to assess the effects of biologics in PSC and associated inflammatory bowel disease (IBD). METHODS: MEDLINE, Scopus, and Embase were searched up to July 31, 2023, for studies reporting the effects of biologics in patients with PSC-IBD. Effects of biologic therapy on alkaline phosphatase, total bilirubin, ulcerative colitis response score, and adverse events were calculated and expressed as standardized difference of means (SMD), proportions, and 95% CI using a random-effects model. RESULTS: Six studies, including 411 PSC-IBD patients who received biologics, were included. Biologic treatment was associated with no change in alkaline phosphatase (SMD: 0.1, 95% CI: -0.07 -0.17, p=0.43), but a small and statistically significant increase in total bilirubin (SMD: 0.2, 95% CI: 0.05-0.35, p<0.01). 31.2% (95% CI: 23.8-39.7) of patients with IBD achieved endoscopic response, and there was a significant improvement in ulcerative colitis response score (SMD: -0.6,95% CI: -0.88 to 0.36, p<0.01). Furthermore, 17.6% (95% CI: 13.0-23.5) of patients experienced adverse events severe enough to discontinue therapy, and 29.9% (95% CI: 25.2-34.8) had a loss of response to biologics. CONCLUSIONS: Treatment of patients with PSC-IBD with biologics (vedolizumab, infliximab, and adalimumab) was not associated with improvement of biochemical markers of cholestasis. Biologics are effective in treating the colitis associated with PSC. Vedolizumab was associated with worsening liver enzymes in contrast to other biologics, a finding that warrants further study.

Cyclosporine vs. tacrolimus after liver transplantation for primary sclerosing cholangitis - a propensity score-matched intention-to-treat analysis.

BACKGROUND & AIMS: There is controversy regarding the optimal calcineurin inhibitor type after liver transplant(ation) (LT) for primary sclerosing cholangitis (PSC). We compared tacrolimus with cyclosporine in a propensity score-matched intention-to-treat analysis based on registries representing nearly all LTs in Europe and the US. METHODS: From the European Liver Transplant Registry (ELTR) and Scientific Registry of Transplant Recipients (SRTR), we included adult patients with PSC undergoing a primary LT between 2000-2020. Patients initially treated with cyclosporine were propensity score-matched 1:3 with those initially treated with tacrolimus. The primary outcomes were patient and graft survival rates. RESULTS: The propensity score-matched sample comprised 399 cyclosporine-treated and 1,197 tacrolimus-treated patients with PSC. During a median follow-up of 7.4 years (IQR 2.3-12.8, 12,579.2 person-years), there were 480 deaths and 231 re-LTs. The initial tacrolimus treatment was superior to cyclosporine in terms of patient and graft survival, with 10-year patient survival estimates of 72.8% for tacrolimus and 65.2% for cyclosporine (p <0.001) and 10-year graft survival estimates of 62.4% and 53.8% (p <0.001), respectively. These findings were consistent in the subgroups according to age, sex, registry (ELTR vs. SRTR), time period of LT, MELD score, and diabetes status. The acute rejection rates were similar between groups. In the multivariable Cox regression analysis, tacrolimus (hazard ratio 0.72, p <0.001) and mycophenolate use (hazard ratio 0.82, p = 0.03) were associated with a reduced risk of graft loss or death, whereas steroid use was not significant. CONCLUSIONS: Tacrolimus is associated with better patient and graft survival rates than cyclosporine and should be the standard calcineurin inhibitor used after LT for patients with PSC. IMPACT AND IMPLICATIONS: The optimal calcineurin inhibitor to use after liver transplantation in patients with primary sclerosing cholangitis has yet to be firmly established. Since randomized trials with long follow-up are unlikely to be performed, multicontinental long-term registry data are essential in informing clinical practices. Our study supports the practice of using tacrolimus instead of cyclosporine in the initial immunosuppressive regimen after liver transplantation for patients with primary sclerosing cholangitis. The retrospective registry-based design is a limitation.

Significant CA 19-9 elevation in IgG4-related autoimmune pancreatitis - A diagnostic dilemma.

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder characterized by dense infiltration of IgG4-positive plasma cells in the affected tissue along with characteristic storiform fibrosis that can lead to the development of tumefactive lesions in any organ. CA19-9 is a marker for pancreato-biliary malignancy, however mild to moderate elevation of CA 19-9 can also be observed in IgG4-RD autoimmune pancreatitis (AIP) and sclerosing cholangitis (IgG4-SC). Therefore, it becomes difficult to differentiate between these entities. We describe the case of a 65-year-old male with history of IgG4-RD, presenting with jaundice and abdominal pain. He was found to have a pancreatic mass with significantly elevated IgG4 162 (2-96 mg/dL and CA19-9 levels 2830 (0-35 U/ml). Patient underwent ERCP and biopsy, which ruled out pancreatic cancer and cholangiocarcinoma. He was diagnosed with IgG4-RD autoimmune pancreatitis (AIP) and sclerosing cholangitis. Treatment with steroids and rituximab resulted in significant improvement in the bilirubin and a dramatic decrease in CA19-9 levels.

Beta-lapachone ameliorates the progression of primary sclerosing cholangitis pathogenesis in rodent models.

AIMS: Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease characterized by chronic inflammation and severe fibrosis for which effective treatment options are currently lacking. In this study, we explored the potential of beta-lapachone (ßL) as a drug candidate for PSC therapy. MATERIALS AND METHODS: We employed an animal model fed a diet containing 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) to assess the preventive and therapeutic effects of ßL. The beneficial effects of ßL on PSC pathogenic characteristics, including blood biomarkers, inflammation, and fibrosis, were determined by assessing relevant parameters. Differential gene expression between each group was analyzed by RNA sequencing of liver tissues. Mdr2-/- mice were utilized to explore the involvement of Abcb4 in the ßL-induced improvement of PSC pathogenesis. KEY FINDINGS: ßL effectively inhibited key features of PSC pathogenesis, as demonstrated by reduced blood biomarkers and improved pathogenic characteristics. Treatment with ßL significantly mitigated DDC-induced apoptosis, cell proliferation, inflammation, and fibrosis. Analysis of differential gene expression confirmed a new insight that ßL could stimulate the expression of genes related to NAD synthesis and Abcb4. Indeed, ßL-induced NAD exhibited effective functioning, as evidenced by enhanced sirt1/3 and acetyl-lysine levels, leading to improved mitochondrial stability. The role of Abcb4 in response to ßL was confirmed in Mdr2/Abcb4 KO mice, where the beneficial effects of ßL were abolished. SIGNIFICANCE: This study provided a new concept for PSC treatment, suggesting that pharmacological stimulation of the NAD synthetic pathway and Abcb4 via ßL ameliorates PSC pathogenesis.

Pembrolizumab-induced immune-related sclerosing cholangitis.

Immunotherapy is increasingly used to treat various types of cancer; however, it can often result in immune-related adverse events (irAEs). Immune-related sclerosing cholangitis (irSC) is a rare type of hepatic irAE that has been described only in a few cases, and much remains unknown about its optimal treatment. In this report, we describe the case of a man in his 70s who was diagnosed with metastatic melanoma and treated with pembrolizumab. He experienced multiple irAEs, including irSC, which did not respond to initial prednisone treatment (2 mg/kg daily dosing). However, subsequent treatment with ursodeoxycholic acid (UDCA) resulted in complete resolution of symptoms and normalisation of laboratory and radiographic abnormalities related to irSC. Our case suggests that steroids, which are traditionally used to treat irAEs, may be ineffective for irSC and that UDCA may be a better alternative. Clinicians should be aware of this rare irAE.