Effects of Vedolizumab in Patients With Primary Sclerosing Cholangitis and Inflammatory Bowel Diseases

Fucoidan modulates gut microbiota and immunity in Peyer's patches against inflammatory bowel disease

Although fucoidan has potential use as an anti-inflammatory agent, the specific mechanisms by which it influences signaling and immunomodulatory pathways between gut microbiota and Peyer's patches remain unclear. Therefore, the aim of this study was to investigate the therapeutic potential of fucoidan in a dextran sulfate sodium (DSS)-induced mouse model of inflammatory bowel disease (IBD) by examining the effects on gut microbiota and the underlying anti-inflammatory mechanisms. Purified fucoidan, which upon characterization revealed structural fragments comprising →3)-β-D-Galp-(1→, →4)-α-L-Fucp-(1→, and →3)-α-L-Fucp-(1→ residues with a sulfation at position C2 was used. Treatment of the mice with fucoidan significantly alleviated the symptoms of IBD and restored the diversity of gut microbiota by enhancing the abundance of Bacteroidetes and reducing the proportion of Firmicutes. The administration of fucoidan also elevated levels of short-chain fatty acids while reducing the levels of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ. Most importantly, fucoidan attenuated the expression of integrin α4β7/MAdCAM-1 and CCL25/CCR9, which are involved in homing intestinal lymphocytes within Peyer's patches. These findings indicate that fucoidan is a promising gut microbiota modulator and an anti-inflammatory agent for IBD.

Immunobiology of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory progressive cholestatic liver disease. Genetic risk factors, the presence of autoantibodies, the strong clinical link with inflammatory bowel disease, and associations with other autoimmune disorders all suggest a pivotal role for the immune system in PSC pathogenesis. In this review, we provide a comprehensive overview of recent immunobiology insights in PSC. A particular emphasis is given to immunological concepts such as tissue residency and knowledge gained from novel technologies, including single-cell RNA sequencing and spatial transcriptomics. This review of the immunobiological landscape of PSC covers major immune cell types known to be enriched in PSC-diseased livers as well as recently described cell types whose biliary localization and contribution to PSC immunopathogenesis remain incompletely described. Finally, we emphasize the importance of time and space in relation to PSC heterogeneity as a key consideration for future studies interrogating the role of the immune system in PSC.

The impact of vedolizumab therapy on extraintestinal manifestations in patients with inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Extraintestinal manifestations (EIMs) pose a significant threat in inflammatory bowel disease (IBD) patients. Vedolizumab (VDZ) primarily affects the gastrointestinal tract. However, its impact on EIMs remains uncertain. Therefore, we conducted this meta-analysis to examine the effects of VDZ on EIMs during treatment.

METHODS

Relevant studies were identified by conducting thorough searches across electronic databases, including PubMed, Ovid Embase, Medline, and Cochrane CENTRAL. Primary outcomes focused on the proportion of patients with resolution for pre-existing EIMs in IBD patients receiving VDZ. Secondary outcomes included the proportion of patients with EIM exacerbations and new onset EIMs during VDZ treatment.

RESULTS

Our meta-analysis encompassed 21 studies. The proportion of patients with resolution of pre-existing EIMs in VDZ-treated IBD patients was 39% (150/386; 95% confidence interval [CI] 0.31-0.48). The proportion of patients with EIM exacerbations occurred at a rate of 28% (113/376; 95% CI 0.05-0.50), while new onset EIMs had a rate of 15% (397/2541; 95% CI 0.10-0.20). Subgroup analysis revealed a 40% (136/337) proportion of patients with resolution for articular-related EIMs and a 50% (9/18) rate for erythema nodosum. Exacerbation rates for arthritis/arthralgia, erythema nodosum/pyoderma gangrenosum, and aphthous stomatitis during VDZ use were 28% (102/328), 18% (7/38), and 11% (3/28), respectively. The incidence rate of newly developed EIMs during treatment was 11% (564/4839) for articular-related EIMs, with other EIMs below 2%.

CONCLUSION

VDZ demonstrates efficacy in skin-related EIMs like erythema nodosum and joint-related EIMs including arthritis, arthralgia, spondyloarthritis, and peripheral joint diseases. Some joint and skin-related EIMs may experience exacerbation during VDZ therapy.

Navigating the pharmacotherapeutic management of comorbid inflammatory bowel disease and primary sclerosing cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is the most specific hepatobiliary extraintestinal manifestation in inflammatory bowel disease (IBD). PSC ultimately has a poor prognosis, with disease progression resulting in liver cirrhosis and subsequent liver failure. While there is current data for the medical management of IBD, the optimal approach for concurrent PSC-IBD is unclear.

AREAS COVERED

This review focuses on the current literature of pharmacotherapy in the PSC-IBD population including anti-tumor necrosis factor agents, vedolizumab, JAK inhibitors, IL-12/23 inhibitors, and thiopurines. Regarding PSC-IBD, it focuses on effectiveness of IBD therapies on liver biochemistry and IBD activity as well as the advent of clinically relevant liver outcomes and safety. The authors also address the need for further advances in research.

EXPERT OPINION

The longer-term data for pharmacological management for IBD is well established. In the concomitant PSC-IBD population there is no drug to date that has effectively reduced disease related morbidity and mortality outcomes. There are limitations in the current, mostly retrospective data on IBD drugs in PSC-IBD with respect to samples sizes, heterogenous outcomes, and lack of a high-quality surrogate endpoint in PSC. However, current data for adalimumab offers encouraging results which require further exploration with larger prospective studies.

Beyond the Gut: A Systematic Review and Meta-analysis of Advanced Therapies for Inflammatory Bowel Disease-associated Extraintestinal Manifestations

BACKGROUND AND AIMS

Extraintestinal manifestations are frequent in patients with inflammatory bowel disease and have a negative impact on quality of life. Currently, however, there is no evidence available to determine which drug should be recommended for these patients beyond anti-tumour necrosis factor [anti-TNF] treatment. We aimed to analyse the frequency of new extraintestinal manifestations and the behaviour of pre-existing extraintestinal manifestations during advanced therapy.

METHODS

We conducted a systematic search on November 15, 2022, and enrolled randomized controlled trials, cohorts, and case series reporting the occurrence and behaviour of extraintestinal manifestations in patients with inflammatory bowel disease receiving advanced therapy [non-TNF inhibitor biologicals and JAK inhibitors]. Proportions of new, recurring, worsening, and improving extraintestinal manifestations were calculated with 95% confidence intervals [CIs]. The risk of bias was assessed with the QUIPS tool.

RESULTS

Altogether, 61 studies comprising 13,806 patients reported eligible data on extraintestinal manifestations. The overall proportion of new extraintestinal manifestations was 8% [95% CI, 6-12%] during advanced therapy. There was no significant difference between the frequency of new extraintestinal manifestations during vedolizumab and ustekinumab therapy [11%, 95% CI, 8-15% vs 6%, 95% CI, 3-11%, p = 0.166]. The improvement of pre-existing manifestations was comparable between vedolizumab- and ustekinumab-treated patients, except for joint involvement [42%, 95% CI, 32-53% vs 54%, 95% CI, 42-65%, p = 0.029].

CONCLUSION

The proportion of new extraintestinal manifestations was low during advanced therapy. Furthermore, the improvement of pre-existing manifestations was comparable between advanced therapies, except for pre-existing joint manifestations.

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.

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.

Gut Microbiota in Primary Sclerosing Cholangitis: From Prognostic Role to Therapeutic Implications

BACKGROUND

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease of unknown etiology characterized by biliary inflammation and periductal fibrosis. The gut microbiota plays a crucial role in the pathogenesis of PSC by regulating bile acid metabolism, inflammation, and immune response. On the other hand, liver disease progression affects the composition of the gut microbiota, fostering these mechanisms in a mutual detrimental way.

SUMMARY

Recent evidences described a specific pro-inflammatory microbial signature in PSC patients, with an overall reduced bacterial diversity and the loss of beneficial metabolites such as short-chain fatty acids. As effective therapies for PSC are still lacking, targeting the gut microbiota offers a new perspective in the management of this disease. To date, antibiotics, fecal microbiota transplantation, and probiotics are the most studied gut microbiota-targeted intervention in PSC, but new potential strategies such as vaccines and bacteriophages represent possible future therapeutic horizons.

KEY MESSAGES

In this review, we focus on the role of the gut microbiota in PSC, considering its pathogenetic and prognostic role and the therapeutic implications.

Efficacy of Biologics in the Treatment of Primary Sclerosing Cholangitis Associated With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

This is the first systematic review and meta-analysis that aims to address the scarcity of research on the use of biological therapy in primary sclerosing cholangitis-inflammatory bowel disease (PSC-IBD) and the historical inadequacy of therapeutic options. Its purpose is to investigate this matter comprehensively and furnish guidance for clinical practice. Utilizing Embase, PubMed, Medline, and clinicaltrials.gov studies investigating the roles of biologics and antibiotics in PSC-IBD were identified. The systematic literature review encompassed articles published from inception through September 2023. Two independent reviewers assessed the articles, and methodological quality was gauged using Review Manager 5.4.2. Nine studies were included in the systematic review and meta-analysis. However, only four met the criteria for inclusion in the meta-analysis due to variability and availability of data; the remaining studies underwent descriptive analysis. Notably, infliximab, adalimumab, vedolizumab, and tofacitinib showed ineffectiveness in reducing cholestatic markers. This review underscores the limited impact of biological and small-molecule therapies on disease progression in PSC-IBD patients, signifying the need for further exploration and development of treatment modalities in this domain.

Integrins in biliary injury and fibrosis

PURPOSE OF REVIEW

Current treatment options for cholangiopathies are severely limited and there is thus a critical need to identify and develop therapies. This review discusses the role of integrins in biliary injury and fibrosis and their potential as therapeutic targets.

RECENT FINDINGS

There are a diverse set of roles that integrins play in biliary injury and fibrosis. Some integrins activate TGF-β signaling or are involved in sensing of the extracellular matrix, making them attractive targets for biliary fibrosis. In recent work, autoantibodies to α v β 6 were identified in patients with PSC, supporting the relevance of this integrin in the disease. In addition, a role for α 2 β 1 in cyst formation was identified in a mouse model of polycystic liver disease. Leukocyte integrins (e.g. α E β 7 and α 4 β 7 ) contribute to lymphocyte trafficking, making them potential targets for biliary inflammation; however, this has not yet translated to the clinic.

SUMMARY

While all members of the same family of proteins, integrins have diverse roles in the pathogenesis of biliary disease. Targeting one or multiple of these integrins may slow or halt the progression of biliary injury and fibrosis by simultaneously impacting different pathologic cells and processes.

Treatment of Primary Sclerosing Cholangitis Including Transplantation

Primary sclerosing cholangitis is a progressive cholestatic liver disease that causes stricturing of the intra and extrahepatic bile ducts that can lead to cirrhosis and end stage liver disease. Effective medical therapy has been elusive, but a course of ursodeoxycholic acid may be prescribed at doses of 17-23 mg/kg/day for up to a year to determine if a reduction in serum alkaline phosphatase is observed. A number of drugs are under investigation, including FXR agonists with choleretic and antimicrobial properties. Liver transplantation for PSC has one of the highest survival rates, but recurrent PSC is seen in up to 25% of recipients.

Inflammatory bowel disease and primary sclerosing cholangitis: One disease or two?

Primary sclerosing cholangitis (PSC) was declared one of the biggest unmet needs in hepatology during International Liver Congress 2016 in Berlin. Since then, not much has changed unfortunately, largely due to the still elusive pathophysiology of the disease. One of the most striking features of PSC is its association with inflammatory bowel disease (IBD), with the majority of patients with PSC being diagnosed with extensive colitis. This review describes the epidemiology of IBD in PSC, its specific phenotype, complications and potential pathophysiological mechanisms connecting the two diseases. Whether PSC is merely an extra-intestinal manifestation of IBD or if PSC and IBD are two distinct diseases that happen to share a common susceptibility that leads to a dual phenotype is debated. Implications for the management of the two diseases together are also discussed. Overall, this review summarises the available data in PSC-IBD and discusses whether PSC and IBD are one or two disease(s).

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.

Microbial Players in Primary Sclerosing Cholangitis: Current Evidence and Concepts

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with progressive biliary inflammation, destruction of the biliary tract, and fibrosis, resulting in liver cirrhosis and end-stage liver disease. To date, liver transplantation is the only definitive treatment option for PSC. The precise etiology of PSC remains elusive, but it is widely accepted to involve a complex interplay between genetic predisposition, immunologic dysfunction, and environmental influence. In recent years, the gut-liver axis has emerged as a crucial pathway contributing to the pathogenesis of PSC, with particular focus on the role of gut microbiota. However, the role of the fungal microbiome or mycobiome has been overlooked for years, resulting in a lack of comprehensive studies on its involvement in PSC. In this review, we clarify the present clinical and mechanistic data and concepts concerning the gut bacterial and fungal microbiota in the context of PSC. This review sheds light on the role of specific microbes and elucidates the dynamics of bacterial and fungal populations. Moreover, we discuss the latest insights into microbe-altering therapeutic approaches involving the gut-liver axis and bile acid metabolism.

Incidence and Prevalence of Primary Sclerosing Cholangitis: A Meta-analysis of Population-based Studies

BACKGROUND

Primary sclerosing cholangitis is a chronic liver disease associated with significant morbidity, mortality, and healthcare utilization. We conducted a systematic review and meta-analysis of population-based studies of the incidence and prevalence of primary sclerosing cholangitis.

METHODS

Medline and Embase were systematically searched to identify population-based studies of a defined geographic area and reported the incidence or prevalence of primary sclerosing cholangitis in the general population. Meta-analyses, using random-effects, were performed to calculate overall and country-specific incidence (per 100 000 persons/year) and prevalence rates (per 100 000 persons) with 95% confidence intervals.

RESULTS

The 14 studies on incidence and the 12 for prevalence originated from North America, Asia, Europe, and Oceania. Incidence and prevalence rates of primary sclerosing cholangitis were 0.87 (95% confidence interval, 0.59-1.29) and 13.53 (95% confidence interval, 10.20-17.94) per 100 000 persons, respectively.

CONCLUSIONS

Both the prevalence and incidence of primary sclerosing cholangitis is low in the general population. Future studies on the incidence and prevalence of primary sclerosing cholangitis in the general population should be directed at Asia, Africa, and Latin America to allow for a more robust assessment of the global epidemiology of primary sclerosing cholangitis.

An overview of recent treatment options for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic hepatic dysfunction characterized by inflammatory and tissue-degenerative strictures of the biliary tree, leading to cirrhosis and cholangiocarcinoma. The pathophysiological mechanisms involve immune-mediated responses. Numerous treatment modalities targeting the inflammatory aspects have been suggested, but a consensus on the best treatment option is lacking. This study aims to review the most up-to-date treatment options for PSC.

Therapeutic modulation of the liver immune microenvironment

Inflammation is a hallmark of progressive liver diseases such as chronic viral or immune-mediated hepatitis, alcohol-associated liver disease, and NAFLD. Preclinical and clinical studies have provided robust evidence that cytokines and related cellular stress sensors in innate and adaptive immunity orchestrate hepatic disease processes. Unresolved inflammation and liver injury result in hepatic scarring, fibrosis, and cirrhosis, which may culminate in HCC. Liver diseases are accompanied by gut dysbiosis and a bloom of pathobionts, fueling hepatic inflammation. Anti-inflammatory strategies are extensively used to treat human immune-mediated conditions beyond the liver, while evidence for immunomodulatory therapies and cell therapy-based strategies in liver diseases is only emerging. The development and establishment of novel immunomodulatory therapies for chronic liver diseases has been dampened by several clinical challenges, such as invasive monitoring of therapeutic efficacy with liver biopsy in clinical trials and risk of DILI in several studies. Such aspects prevented advancements of novel medical therapies for chronic inflammatory liver diseases. New concepts modulating the liver immune environment are studied and eagerly awaited to improve the management of chronic liver diseases in the future.

Current Therapeutics in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is an orphan, cholestatic liver disease that is characterized by inflammatory biliary strictures with variable progression to end-stage liver disease. Its pathophysiology is poorly understood. Chronic biliary inflammation is likely driven by immune dysregulation, gut dysbiosis, and environmental exposures resulting in gut-liver crosstalk and bile acid metabolism disturbances. There is no proven medical therapy that alters disease progression in PSC, with the commonly prescribed ursodeoxycholic acid being shown to improve liver biochemistry at low-moderate doses (15-23 mg/kg/day) but not alter transplant-free survival or liver-related outcomes. Liver transplantation is the only option for patients who develop end-stage liver disease or refractory complications of PSC. Immunosuppressive and antifibrotic agents have not proven to be effective, but there is promise for manipulation of the gut microbiome with fecal microbiota transplantation and antibiotics. Bile acid manipulation via alternate synthetic bile acids such as norursodeoxycholic acid, or interaction at a transcriptional level via nuclear receptor agonists and fibrates have shown potential in phase II trials in PSC with several leading to larger phase III trials. In view of the enhanced malignancy risk, statins, and aspirin show potential for reducing the risk of colorectal cancer and cholangiocarcinoma in PSC patients. For patients who develop clinically relevant strictures with cholestatic symptoms and worsening liver function, balloon dilatation is safer compared with biliary stent insertion with equivalent clinical efficacy.

Therapeutic Antibodies in Medicine

Antibody engineering has developed into a wide-reaching field, impacting a multitude of industries, most notably healthcare and diagnostics. The seminal work on developing the first monoclonal antibody four decades ago has witnessed exponential growth in the last 10-15 years, where regulators have approved monoclonal antibodies as therapeutics and for several diagnostic applications, including the remarkable attention it garnered during the pandemic. In recent years, antibodies have become the fastest-growing class of biological drugs approved for the treatment of a wide range of diseases, from cancer to autoimmune conditions. This review discusses the field of therapeutic antibodies as it stands today. It summarizes and outlines the clinical relevance and application of therapeutic antibodies in treating a landscape of diseases in different disciplines of medicine. It discusses the nomenclature, various approaches to antibody therapies, and the evolution of antibody therapeutics. It also discusses the risk profile and adverse immune reactions associated with the antibodies and sheds light on future applications and perspectives in antibody drug discovery.

Use of IBD Drugs in Patients With Hepatobiliary Comorbidities: Tips and Tricks

Advanced therapies (biologic agents and small molecules) for inflammatory bowel diseases (IBD) have radically changed the management of these diseases during the last decade. Data about these drugs in patients with hepatic disorders derive mainly from real-life studies, as these conditions often represent an exclusion criterion from pivotal drug developmental trials. However, IBD patients sometimes have concomitant liver diseases. Nonalcoholic fatty liver disease is the most prevalent hepatic comorbidity, whereas viral hepatitis, primary sclerosing cholangitis, primary biliary cholangitis, autoimmune hepatitis, and hepatic vascular disorders are less frequent. This review aimed at describing the real-life data about the use of advanced therapies for IBD in patients with concomitant hepatobiliary disorders. Hepatitis B virus and hepatitis C virus infections do not represent an absolute contraindication for novel IBD therapeutic agents. Data from the literature suggest a safe hepatobiliary profile of biologic agents and small molecules in the case of nonalcoholic fatty liver disease, autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cholangitis, and portal vein thrombosis. Consequently, although the liver disease does not affect a different therapeutic approach in patients with concomitant IBD and liver disease, a close risk/benefit analysis for each drug should be performed in these patients, especially in cirrhotic patients and in the postliver transplant setting.

Recruitment and Residence of Intestinal T Cells - Lessons for Therapy in Inflammatory Bowel Disease

Targeting leukocyte trafficking in the management of inflammatory bowel disease [IBD] has been a significant therapeutic advance over the past 15 years. However, as with other advanced therapies, phase III clinical trials report response to trafficking inhibitors in only a proportion of patients, with fewer achieving clinical remission or mucosal healing. Additionally, there have been significant side effects, most notably progressive multifocal leukoencephalopathy in association with the α4 inhibitor natalizumab. This article reviews the mechanisms underpinning T cell recruitment and residence, to provide a background from which the strength and limitations of agents that disrupt leukocyte trafficking can be further explored. The therapeutic impact of trafficking inhibitors is underpinned by the complexity and plasticity of the intestinal immune response. Pathways essential for gut homing in health may be bypassed in the inflamed gut, thus providing alternative routes of entry when conventional homing molecules are targeted. Furthermore, there is conservation of trafficking architecture between proinflammatory and regulatory T cells. The persistence of resident memory cells within the gut gives rise to local established pro-inflammatory populations, uninfluenced by inhibition of trafficking. Finally, trafficking inhibitors may give rise to effects beyond the intended response, such as the impact of vedolizumab on innate immunity, as well as on target side effects. With significant research efforts into predictive biomarkers already underway, it is ultimately hoped that a better understanding of trafficking and residence will help us predict which patients are most likely to respond to inhibition of leukocyte trafficking, and how best to combine therapies.

Current Therapies for Cholestatic Diseases

Cholestasis is a condition characterized by decrease in bile flow due to progressive pathological states that lead to chronic cholestatic liver diseases which affect the biliary tree at the intrahepatic level and extrahepatic level. They induce complications such as cirrhosis, liver failure, malignancies, bone disease and nutritional deficiencies that merit close follow-up and specific interventions. Furthermore, as those conditions progress to liver cirrhosis, there will be an increase in mortality but also an important impact in quality of life and economic burden due to comorbidities related with liver failure. Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. With a general view of therapeutic options and their molecular targets, this review addresses the pathophysiology of cholangiopathies. The objective is to provide clinicians with an overview of the safety and efficacy of the treatment of cholangiopathies based on the current evidence.

Colitis ameliorates cholestatic liver disease via suppression of bile acid synthesis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the biliary tree. The majority of PSC patients suffer from concomitant inflammatory bowel disease (IBD), which has been suggested to promote disease development and progression. However, the molecular mechanisms by which intestinal inflammation may aggravate cholestatic liver disease remain incompletely understood. Here, we employ an IBD-PSC mouse model to investigate the impact of colitis on bile acid metabolism and cholestatic liver injury. Unexpectedly, intestinal inflammation and barrier impairment improve acute cholestatic liver injury and result in reduced liver fibrosis in a chronic colitis model. This phenotype is independent of colitis-induced alterations of microbial bile acid metabolism but mediated via hepatocellular NF-κB activation by lipopolysaccharide (LPS), which suppresses bile acid metabolism in-vitro and in-vivo. This study identifies a colitis-triggered protective circuit suppressing cholestatic liver disease and encourages multi-organ treatment strategies for PSC.

Colectomy in patients with ulcerative colitis is not associated to future diagnosis of primary sclerosing cholangitis

BACKGROUND

Primary Sclerosing Cholangitis (PSC) is a hepatobiliary disease closely related to ulcerative colitis (UC). In PSC patients, colectomy has been linked to improved prognosis, especially following liver transplantation. This suggests an involvement of the gut-liver axis in PSC etiology.

OBJECTIVE

We aimed to investigate the association between colectomy and the risk of future PSC in an epidemiological setting.

METHOD

Through nationwide registers, we identified all adults diagnosed with UC in Sweden 1990-2018 and retrieved information on PSC diagnosis and colectomy. Within the UC cohort (n = 61,993 patients), we matched 5577 patients with colectomy to 15,078 without colectomy. Matching criteria were sex, age at UC onset (±5 years), year of UC onset (±3 years), and proctitis at the time of colectomy. Incidence rates of PSC per 1000-person year were calculated, and the Cox proportional hazard regression model estimated hazard ratios (HRs) for PSC until 31 December 2019.

RESULTS

During the follow-up, 190 (3.4%) colectomized UC patients and 450 (3.0%) UC comparators developed PSC, yielding incidence rates of 2.6 and 2.4 per 1000 person-years (HR 1.07 [95% CI 0.90-1.28]). The cumulative incidence of colectomy decreased remarkably over calendar periods, but the cumulative incidence of PSC remained unchanged. The risk of developing PSC in colectomized versus comparators changed over time (HR 0.68 [95% CI; 0.48-0.96] in 1990-97 and HR 2.10 [95% CI; 1.37-3.24] in 2011-18).

CONCLUSIONS

In UC patients, colectomy was not associated with a decreased risk of subsequent PSC. The observed differences in the risk of PSC development over calendar periods are likely due to changes in PSC-diagnosis and UC-treatment.

Outcomes of immunomodulator and advanced therapies for primary sclerosing cholangitis-associated inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) coexists in up to 80% of patients with primary sclerosing cholangitis (PSC). The aim of this study is to investigate the outcomes of immunomodulator (IMM)/advanced therapies for the treatment of PSC-IBD.

METHODS

This was a single-center, retrospective study of patients with PSC from 1 January 2012 to 1 April 2021. Adult patients (age ≥ 18 years) with PSC-IBD were included. Primary outcomes were rates and predictors of IMM/advanced therapies to treat PSC-IBD. Secondary outcomes included rates of cholangitis, PSC-IBD clinical remission, and endoscopic healing.

RESULTS

A total of 106 patients with PSC were reviewed and 72 (68%) with confirmed PSC-IBD were included in the study. The median age was 48 years (IQR, 33-59.5) and 69.4% were male. Overall, 28 patients (38.9%) required IMM/advanced therapies to treat PSC-IBD (22 biologic/small molecule therapy and six thiopurine monotherapy). Patients in the IMM/advanced therapies group were more likely to have small bowel involvement (32.1% vs. 4.6%; P = 0.002). In the IMM/advanced therapies group, clinical remission was achieved in 78.6% but endoscopic healing in only 50%. The rate of acute ascending cholangitis was 42.9% in the IMM/advanced therapies group compared with 31.8% in the non-IMM/advanced therapies group (P = 0.34).

CONCLUSION

In our cohort, up to a third of patients with PSC-IBD required IMM/advanced therapies with only 50% of these patients achieving endoscopic healing. The use of IMM/advanced therapies was not associated with a higher risk of cholangitis, but larger studies are needed to investigate the risk with different classes of advanced therapies.

The microbiota and the gut-liver axis in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) offers unique opportunities to explore the gut-liver axis owing to the close association between liver disease and colonic inflammation. It is well established that the gut microbiota in people with PSC differs from that of healthy individuals, but details of the microbial factors that demarcate PSC from inflammatory bowel disease (IBD) without PSC are poorly understood. In this Review, we aim to provide an overview of the latest literature on the gut microbiome in PSC and PSC with IBD, critically examining hypotheses on how microorganisms could contribute to the pathogenesis of PSC. A particular emphasis will be put on pathogenic features of the gut microbiota that might explain the occurrence of bile duct inflammation and liver disease in the context of IBD, and we postulate the potential existence of a specific yet unknown factor related to the gut-liver axis as causative in PSC. Available data are scrutinized in the perspective of therapeutic approaches related to the gut-liver axis.

Gut immune cell trafficking: inter-organ communication and immune-mediated inflammation

Immune cell trafficking is a complex and tightly regulated process that is indispensable for the body's fight against pathogens. However, it is also increasingly acknowledged that dysregulation of cell trafficking contributes to the pathogenesis of immune-mediated inflammatory diseases (IMIDs) in gastroenterology and hepatology, such as inflammatory bowel disease and primary sclerosing cholangitis. Moreover, altered cell trafficking has also been implicated as a crucial step in the immunopathogenesis of other IMIDs, such as rheumatoid arthritis and multiple sclerosis. Over the past few years, a central role of the gut in mediating these disorders has progressively emerged, and the partly microbiota-driven imprinting of particular cell trafficking phenotypes in the intestine seems to be crucially involved. Therefore, this Review highlights achievements in understanding immune cell trafficking to, within and from the intestine and delineates its consequences for immune-mediated pathology along the gut-liver, gut-joint and gut-brain axes. We also discuss implications for current and future therapeutic approaches that specifically interfere with homing, retention, egress and recirculation of immune cells.

Autologous regulatory T-cell transfer in refractory ulcerative colitis with concomitant primary sclerosing cholangitis

OBJECTIVE

Ulcerative colitis (UC) is a chronic, debilitating immune-mediated disease driven by disturbed mucosal homeostasis, with an excess of intestinal effector T cells and an insufficient expansion of mucosal regulatory T cells (Tregs). We here report on the successful adoptive transfer of autologous, ex vivo expanded Tregs in a patient with refractory UC and associated primary sclerosing cholangitis (PSC), for which effective therapy is currently not available.

DESIGN

The patient received a single infusion of 1×10⁶ autologous, ex vivo expanded, polyclonal Tregs per kilogram of body weight, and the clinical, biochemical, endoscopic and histological responses were assessed 4 and 12 weeks after adoptive Treg transfer.

RESULTS

The patient showed clinical, biochemical, endoscopic and histological signs of response until week 12 after adoptive Treg transfer, which was associated with an enrichment of intestinal CD3⁺/FoxP3⁺ and CD3⁺/IL-10⁺ T cells and increased mucosal transforming growth factor beta and amphiregulin levels. Moreover, there was marked improvement of PSC with reduction of liver enzymes. This pronounced effect lasted for 4 weeks before values started to increase again.

CONCLUSION

These findings suggest that adoptive Treg therapy might be effective in refractory UC and might open new avenues for clinical trials in PSC.

TRIAL REGISTRATION NUMBER

NCT04691232.

Ursodeoxycholic acid is associated with improved long-term outcome in patients with primary sclerosing cholangitis

BACKGROUND

It remains unclear whether ursodeoxycholic acid (UDCA) treatment improves long-term outcomes in patients with primary sclerosing cholangitis (PSC). In this study, we investigated whether UDCA treatment is associated with improved liver transplantation (LT)-free survival in a cohort of Japanese patients with PSC.Journal instruction requires a city and country for affiliations; however, these are missing in affiliation [6]. Please verify if the provided city and country are correct and amend if necessary.'Tokyo, Japan' is correct.

METHODS

We used retrospective data from the Japanese PSC registry that included 435 patients with PSC. In this study, we enrolled patients with a complete dataset at diagnosis, along with the diagnosis year, treatment protocol, follow-up period, and outcome data. The association between UDCA treatment and all-cause death or LT was analyzed using Cox regression and inverse probability of UDCA treatment weighting (IPTW)-adjusted Cox regression models adjusted for covariates.

RESULTS

Among 435 patients with PSC, 110 were excluded due to insufficient or missing data, and the remaining 325 patients (male, 187 (58%); mean age at diagnosis, 45.8 years) were enrolled. The mean follow-up period was 5.1 years, and 57 deaths and 24 LTs occurred during observation. UDCA was administered to 278 patients (86%). The Cox regression model demonstrated that UDCA treatment was associated with an improvement in LT-free survival [adjusted hazard ratio (aHR) 0.47, 95% confidence interval (CI) 0.28-0.78, p = 0.003]. In addition, the IPTW-adjusted model indicated a significant association between UDCA and LT-free survival (aHR 0.43, 95% CI 0.25-0.75, p = 0.020). Sensitivity analysis excluding patients treated with bezafibrate indicated a similarly significant association between UDCA treatment and LT-free survival.

CONCLUSION

In this Japanese PSC cohort, UDCA treatment was significantly associated with improved LT-free survival.

EASL Clinical Practice Guidelines on sclerosing cholangitis

Management of primary or secondary sclerosing cholangitis is challenging. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics including diagnostic methods, prognostic assessment, early detection of complications, optimal care pathways and therapeutic (pharmacological, endoscopic or surgical) options both in adults and children.

Positioning biologics in the treatment of IBD: A practical guide - Which mechanism of action for whom?

The number of available biological therapies have doubled over the last 10 years and the arrival of novel molecules (interleukin 23p19 inhibitors) is ongoing alongside the development of small molecules. As a result of this vast landscape of treatment, positioning advanced therapies (according to clinical situation, efficacy and safety) is of paramount importance to providing personalized, appropriate IBD treatment. In this publication the recent available literature is summarized for practical integration into clinical practice including comparative efficacy data, patient and disease demographics. We refer to recent publications and expert opinion in order to facilitate the decision making process of positioning biologicals IBD treatment.

Choosing the right biologic for complications of inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition that involves the intestinal tract, and can also present with extra-intestinal manifestations (EIM). Choosing the right treatment for IBD is often nuanced and decisions can become even more complicated when a patient presents with or develops a complication of the disease.

AREAS COVERED

We aimed to provide an overview of the most common complications of IBD, specifically intestinal and EIM, and summarize the data regarding biologic therapy for treatment of these conditions. A comprehensive literature review was performed using PubMed and Medline databases to identify studies published in the English language relevant to the broad scope of this review.

EXPERT OPINION

There are still significant gaps in our understanding of the pathophysiology of IBD and its treatment, especially in regards to complications of the disease. As novel therapies continue to emerge for treatment of IBD, we feel concurrent examination of their impact on intestinal complications and EIM of IBD is important and should be a priority of future research.

Biological therapies in patients with liver disease: are they really lifesavers?

INTRODUCTION

The liver plays a key role in the setting of immune tolerance. Targeting antigens for presentation by antigen-presenting cells in the liver can induce immune tolerance to either autoantigens from the liver itself or organs outside of the liver. Despite its non-conventional capacity for tolerance induction, the liver remains a target organ for autoimmune diseases. Whereas chronic inflammation and intra-hepatic immuno-suppressive microenvironment occurring during liver fibrosis lead to hepatocellular carcinoma. Monoclonal antibodies have revolutionized the therapeutic strategies of many autoimmune diseases and some cancers.

AREAS COVERED

We review data from literature regarding the safety and efficacy of biologics in treating hepatobiliary autoimmune diseases and primary liver cancers. Furthermore, we describe their potential use in the setting of liver transplants and their main immune-related liver adverse events.

EXPERT OPINION

Biological therapies have changed the natural history of main autoimmune diseases and solid cancers. Compared to other organs and disease settings, the liver lags behind in biologics and their applications. The development of novel diagnostic and therapeutic strategies based on the immunological and antigenic characteristics of the hepatobiliary system could reduce mortality and transplant rates linked to chronic liver diseases.

Treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by progressive fibro-stenotic strictures and destruction of the biliary tree. Currently, there is no effective treatment which can delay its progression or ameliorate the transplant-free survival. Moreover, a major chontroversy in PSC is whether to use UDCA. More recently, novel pharmacological agents emerged aiming at: i) modulation of bile composition; ii) immunomodulation; iii) targeting the gut microbiome; iv) targeting fibrosis. Successful PSC therapy, however, will be most likely a personalized combination of different drugs plus endoscopic treatment. This review aims at offering an overview on the experimental pharmacological strategies currently exploited for PSC treatment.

Gut-Liver Immune Traffic: Deciphering Immune-Pathogenesis to Underpin Translational Therapy

The tight relationship between the gut and liver on embryological, anatomical and physiological levels inspired the concept of a gut-liver axis as a central element in the pathogenesis of gut-liver axis diseases. This axis refers to the reciprocal regulation between these two organs causing an integrated system of immune homeostasis or tolerance breakdown guided by the microbiota, the diet, genetic background, and environmental factors. Continuous exposure of gut microbiome, various hormones, drugs and toxins, or metabolites from the diet through the portal vein adapt the liver to maintain its tolerogenic state. This is orchestrated by the combined effort of immune cells network: behaving as a sinusoidal and biliary firewall, along with a regulatory network of immune cells including, regulatory T cells and tolerogenic dendritic cells (DC). In addition, downregulation of costimulatory molecules on hepatic sinusoids, hepatocytes and biliary epithelial cells as well as regulating the bile acids chain also play a part in hepatic immune homeostasis. Recent evidence also demonstrated the link between changes in the gut microbiome and liver resident immune cells in the progression of cirrhosis and the tight correlation among primary sclerosing cholangitis (PSC) and also checkpoint induced liver and gut injury. In this review, we will summarize the most recent evidence of the bidirectional relationship among the gut and the liver and how it contributes to liver disease, focusing mainly on PSC and checkpoint induced hepatitis and colitis. We will also focus on completed therapeutic options and on potential targets for future treatment linking with immunology and describe the future direction of this research, taking advantage of modern technologies.

The Role of Microbiota in Primary Sclerosing Cholangitis and Related Biliary Malignancies

Primary sclerosing cholangitis (PSC) is an immune-related cholangiopathy characterized by biliary inflammation, cholestasis, and multifocal bile duct strictures. It is associated with high rates of progression to end-stage liver disease as well as a significant risk of cholangiocarcinoma (CCA), gallbladder cancer, and colorectal carcinoma. Currently, no effective medical treatment with an impact on the overall survival is available, and liver transplantation is the only curative treatment option. Emerging evidence indicates that gut microbiota is associated with disease pathogenesis. Several studies analyzing fecal and mucosal samples demonstrate a distinct gut microbiome in individuals with PSC compared to healthy controls and individuals with inflammatory bowel disease (IBD) without PSC. Experimental mouse and observational human data suggest that a diverse set of microbial functions may be relevant, including microbial metabolites and bacterial processing of pharmacological agents, bile acids, or dietary compounds, altogether driving the intrahepatic inflammation. Despite critical progress in this field over the past years, further functional characterization of the role of the microbiota in PSC and related malignancies is needed. In this review, we discuss the available data on the role of the gut microbiome and elucidate important insights into underlying pathogenic mechanisms and possible microbe-altering interventions.

Systematic review and meta-analysis: the impact of co-occurring immune-mediated inflammatory diseases on the disease localization and behavior of Crohn's disease

BACKGROUND

Patients with Crohn's disease (CD) are at increased risk of co-occurring immune-mediated inflammatory diseases (IMIDs). As discrepancy exists regarding the phenotypic presentation of CD among patients with such co-occurring IMIDs, we aimed to conduct a systematic review with meta-analysis characterizing the phenotype of CD among this subgroup of patients.

METHODS

PubMed, Embase, and Scopus were searched from their earliest records to October 2019 for studies reporting the behavior and localization of CD according to the Vienna or Montreal Classifications and CD-related surgery in patients with co-occurring IMIDs. These studies were the subject of a random effect meta-analysis.

RESULTS

After reviewing 24,413 studies, we identified a total of 23 studies comprising 1572 and 35,043 CD patients with and without co-occurring IMIDs, respectively, that fulfilled our inclusion criteria. Overall, patients with co-occurring IMIDs were more likely to have upper gastrointestinal inflammation than were patients without co-occurring IMIDs [relative risk (RR) = 1.49 (95% confidence interval (CI) 1.09-2.04), p = 0.01, I 2 = 7%]. In addition, presence of primary sclerosing cholangitis (PSC) was associated with a lower occurrence of ileal affection [RR = 0.44 (95% CI 0.24-0.81), p < 0.01, I 2 = 32%], increased occurrence of colonic affection [RR = 1.78 (95% CI 1.33-2.38), p < 0.01, I 2 = 32%] and an increased likelihood of non-stricturing and non-penetrating behavior [RR = 1.43 (95% CI 0.97-2.11), p = 0.07, I 2 = 86%]. The latter reached significance when cumulating different IMIDs [RR = 1.30 (95% CI 1.09-1.55), p < 0.01, I 2 = 88%]. CD patients with PSC also underwent fewer CD-related surgeries [RR = 0.55 (95% CI 0.34-0.88), p = 0.01, I 2 = 0%], irrespective of CD location or behavior.

CONCLUSION

This study emphasizes that CD patients with co-existing PSC are likely to have a unique inflammatory distribution primarily confined to the colon, while patients with IMIDs in general have higher likelihood of affection of upper gastrointestinal tract and a non-stricturing and non-penetrating behavior. As such a phenotype of CD is typically associated with a milder disease course; future studies are needed to confirm these results.

The Management of Cholestatic Liver Diseases: Current Therapies and Emerging New Possibilities

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are two chronic cholestatic liver diseases affecting bile ducts that may progress to biliary cirrhosis. In the past few years, the increasing knowledge in the pathogenesis of both diseases led to a growing number of clinical trials and possible new targets for therapy. In this review, we provide an update on the treatments in clinical use and summarize the new drugs in trials for PBC and PSC patients. Farnesoid X Receptor (FXR) agonists and Pan-Peroxisome Proliferator-Activated Receptor (PPAR) agonists are the most promising agents and have shown promising results in both PBC and PSC. Fibroblast Growth Factor 19 (FGF19) analogues also showed good results, especially in PBC, while, although PBC and PSC are autoimmune diseases, immunosuppressive drugs had disappointing effects. Since the gut microbiome could have a potential role in the pathogenesis of PSC, recent research focused on molecules that could change the microbiome, with good results. The near future of the medical management of these diseases may include new treatments or a combination of multiple drugs targeting different signaling pathways at different stages of the diseases.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic liver disease characterized by inflammatory destruction of the intrahepatic and/or extrahepatic bile ducts, leading to bile stasis, fibrosis, and ultimately to cirrhosis, and often requires liver transplantation (LT). PSC occurs more commonly in men, and is typically diagnosed between the ages of 30 and 40. Most cases occur in association with inflammatory bowel disease (IBD), which often precedes the development of PSC. PSC is usually diagnosed after detection of cholestasis during health evaluation or screening of patients with IBD. When symptomatic, the most common presenting symptoms are abdominal pain, pruritus, jaundice or fatigue. The etiology of PSC is poorly understood, but an increasing body of evidence supports the concept of cholangiocyte injury as a result of environmental exposure and an abnormal immune response in genetically susceptible individuals. PSC is a progressive disease, yet no effective medical therapy for halting disease progression has been identified. Management of PSC is mainly focused on treatment of symptoms and addressing complications. PSC can be complicated by bacterial cholangitis, dominant strictures (DSs), gallbladder polyps and adenocarcinoma, cholangiocarcinoma (CCA) and, in patients with IBD, colorectal malignancy. CCA is the most common malignancy in PSC with a cumulative lifetime risk of 10-20%, and accounts for a large proportion of mortality in PSC. LT is currently the only life-extending therapeutic approach for eligible patients with end-stage PSC, ultimately required in approximately 40% of patients. LT secondary to PSC has an excellent outcome compared to other LT indications, although the disease can recur and result in morbidity post-transplant.

Recent advances in the treatment of primary sclerosing cholangitis

Introduction: PSC is a rare liver disease that leads frequently to cirrhosis and need for liver transplantation. No medical treatment is of proven value. Liver transplantation is the only curative therapy available. There is a big medical need to find medical therapy that can alter the natural history of the disease.Areas covered: The authors highlight advances in PSC, based on recent literature retrieved from PubMed until September 2020 regarding both medical and endoscopic biliary therapy.Future possibilities for treatment of PSC are discussed.Expert opinion: Biliary endoscopy is the cornerstone in the treatment of dominant strictures. Single-user peroral cholangioscopy is an emerging modality. Balloon dilatation therapy is the treatment of choice of dominant strictures. The most promising medical therapies showing efficacy in phase II trials are nor-Ursodeoxycholic acid, obethicolic acid, the non-steroidal FXR agonist Cilofexor and Aldafermin, a synthetic analogue of FGF-19. Antibiotics, particularly vancomycin have shown potential benefits, particularly in children but phase III studies are lacking. In observational studies of effects of biological therapy in patients with IBD/PSC adalimumab was associated with reduction in ALP. Results of liver transplantation are favorable but recurrence can be of clinical relevance particularly in patients transplanted before the age of 40.

Metabolomic Signatures of Autoimmune Hepatitis in the Development of Cirrhosis

Objectives: Autoimmune hepatitis (AIH) can progress into severe outcomes, i.e., decompensated cirrhosis, from remarkable and persistent inflammation in the liver. Considering the energy-expending nature of inflammation, we tried to define the metabolomics signatures of AIH to uncover the underlying mechanisms of cirrhosis development and its metabolic biomarkers. Methods: Untargeted metabolomics analysis was performed on sera samples from 79 AIH patients at the stages (phenotypes) of non-cirrhosis (n = 27), compensated cirrhosis (n = 22), and decompensated cirrhosis (n = 30). Pattern recognition was used to find unique metabolite fingerprints of cirrhosis with or without decompensation. Results: Out of the 294 annotated metabolites identified, 2 metabolic fingerprints were found associated with the development of cirrhosis (independent of the decompensated state, 42 metabolites) and the evolution of decompensated cirrhosis (out of 47 metabolites), respectively. The cirrhosis-associated fingerprints (eigenmetabolite) showed better capability to differentiate cirrhosis from non-cirrhosis patients than the aminotransferase-to-platelet ratio index. From the metabolic fingerprints, we found two pairs of metabolites (Mesobilirubinogen/6-Hydroxynicotinic acid and LysoPA(8:0/0:0)/7alpha-Hydroxycholesterol) calculated as ratio of intensities, which revealed robust abilities to identify cirrhosis or predict decompensated patients, respectively. These phenotype-related fingerprint metabolites featured fundamental energy supply disturbance along with the development of AIH cirrhosis and progression to decompensation, which was characterized as increased lipolysis, enhanced proteolysis, and increased glycolysis. Conclusions: Remodeling of metabolism to meet the liver inflammation-related energy supply is one of the key signatures of AIH in the development of cirrhosis and decompensation. Therefore, drug regulation metabolism has great potential in the treatment of AIH.

A Fibrosis-Independent Hepatic Transcriptomic Signature Identifies Drivers of Disease Progression in Primary Sclerosing Cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a heterogeneous cholangiopathy characterized by progressive biliary fibrosis. RNA sequencing of liver tissue from patients with PSC (n = 74) enrolled in a 96-week clinical trial was performed to identify associations between biological pathways that were independent of fibrosis and clinical events.

APPROACH AND RESULTS

The effect of fibrosis was subtracted from gene expression using a computational approach. The fibrosis-adjusted gene expression patterns were associated with time to first PSC-related clinical event (e.g., cholangitis, hepatic decompensation), and differential expression based on risk groups and Ingenuity Pathway Analysis were performed. Baseline demographic data were representative of PSC: median age 48 years, 71% male, 49% with inflammatory bowel disease, and 44% with bridging fibrosis or cirrhosis. The first principle component (PC1) of RNA-sequencing data accounted for 18% of variance and correlated with fibrosis stage (ρ = -0.80; P < 0.001). After removing the effect of fibrosis-related genes, the first principle component was not associated with fibrosis (ρ = -0.19; P = 0.11), and a semisupervised clustering approach identified two distinct patient clusters with differential risk of time to first PSC-related event (P < 0.0001). The two groups had similar fibrosis stage, hepatic collagen content, and α-smooth muscle actin expression by morphometry, Enhanced Liver Fibrosis score, and serum liver biochemistry, bile acids, and IL-8 (all P > 0.05). The top pathways identified by Ingenuity Pathway Analysis were eukaryotic translation inhibition factor 2 (eIF2) signaling and regulation of eIF4/p70S6K signaling. Genes involved in the unfolded protein response, activating transcription factor 6 (ATF6) and eIF2, were differentially expressed between the PSC clusters (down-regulated in the high-risk group by log-fold changes of -0.18 [P = 0.02] and -0.16 [P = 0.02], respectively). Clinical events were enriched in the high-risk versus low-risk group (38% [12/32] vs. 2.4% [1/42], P < 0.0001).

CONCLUSIONS

Removing the contribution of fibrosis-related pathways uncovered alterations in the unfolded protein response, which were associated with liver-related complications in PSC.

Vedolizumab and Extraintestinal Manifestations in Inflammatory Bowel Disease

In Crohn's disease and ulcerative colitis, inflammation is not limited to the digestive tract. Extraintestinal manifestations (EIMs), which affect up to 50% of patients, can substantially impair quality of life. EIMs may parallel luminal disease activity or have an independent course. They most commonly involve the musculoskeletal system (e.g., peripheral or axial arthritis) and skin (e.g., erythema nodosum and pyoderma gangrenosum). Less commonly, the hepatobiliary tract (e.g., primary sclerosing cholangitis [PSC]) and the eye (e.g., episcleritis, scleritis, and uveitis) are involved. Although the pathophysiology of EIMs is poorly understood, they are likely either manifestations of a primary systemic immune disease with variable expression amongst organs, or secondary phenomena to bowel inflammation. Additional pathophysiologic mechanisms may include aberrant lymphocyte homing mediated by ectopic expression of gut-specific chemokines and adhesion molecules, cross-reactivity between microbial and self-antigens, autoantibodies against epitopes shared by the intestine and extraintestinal tissues, elevated serum concentrations of cytokines, and alterations in innate immunity. Many EIMs independent of intestinal disease activity can be successfully treated with tumor necrosis factor (TNF) antagonists. The efficacy of vedolizumab-a monoclonal antibody targeting the α4β7 integrin-for the treatment of EIMs is uncertain, but data are emerging from post hoc analyses of randomized controlled trials, prospective and retrospective cohort studies, and case series. Vedolizumab may be effective in treating EIMs related to luminal disease activity (e.g., type 1 peripheral arthritis and erythema nodosum) but has not shown biochemical improvement in PSC. Its postulated role in the development of de novo EIMs is heavily confounded by the high proportion of patients previously exposed to TNF antagonists; new EIMs could result from TNF antagonist treatment cessation rather than being caused by vedolizumab. A common limitation of clinical studies is the lack of multidisciplinary involvement in the diagnosis and monitoring of EIMs, which may lead to misdiagnosis and overreporting. Future studies should rigorously measure EIMs in parallel with objective measures of luminal disease activity to provide more robust data on the relative efficacy of new drugs, especially as increasing numbers of gut-selective compounds enter clinical development.

Predicting Therapeutic Response in Pediatric Ulcerative Colitis-A Journey Towards Precision Medicine

Ulcerative colitis (UC) is a disabling disease, characterized by chronic inflammation of the colon, with a rising prevalence worldwide in the pediatric age group. Although UC presents in children with varying severity, disease extent, and comorbidities, initial treatment is essentially uniform, consisting of 5-aminosalicylate drugs with corticosteroid induction for those with moderately to severely active disease. With the advent of anti-tumor necrosis factor (TNF) biologic therapy and several new biologics and small-molecule drugs for UC, precision medicine approaches to treatment are needed to more rapidly achieve sustained remission, restore quality of life, normalize development, and limit exposure to toxic corticosteroids in children with UC. Here, we review available data on clinical, biochemical, histopathologic, and molecular predictors of treatment response in UC. We also address known predictors and special treatment considerations in specific relevant scenarios such as very-early-onset UC, acute severe UC, ileal pouch anal anastomosis, and UC with concomitant primary sclerosing cholangitis. The review concludes with a prediction of how machine learning will integrate multimodal patient data to bring precision medicine to the bedside of children with UC in the future.

Autoimmune hepatitis, primary sclerosing cholangitis, and inflammatory bowel disease. Sequential overlap syndrome: a twist to the mosaic of autoimmunity

Autoimmune liver diseases can overlap resulting in a new entity, phenotypically different from those pathologies that converge, and that demonstrates the complexity of our immune system. Sequential overlap syndrome is the consecutive presentation, separated by a variable period of time, of two liver autoimmune diseases, mostly autoimmune hepatitis and primary biliary cholangitis. This syndrome constitutes a challenge both in its diagnosis and in its treatment given the exceptional nature of its presentation. The theory of a mosaic of autoimmunity is proposed to describe this phenomenon.