A review of the medical treatment of primary sclerosing cholangitis in the 21st century

Rare liver diseases in Egypt: Clinical and epidemiological characterization

Illnesses that afflict a tiny number of individuals are referred to as rare diseases (RDs), sometimes called orphan diseases. The local healthcare systems are constantly under financial, psychological, and medical strain due to low incidence rates, unusual presentations, flawed diagnostic standards, and a lack of treatment alternatives for these RDs. The effective management of the once widely spread viral hepatitis B and C has altered the spectrum of liver diseases in Egypt during the last several years. The detection of uncommon disorders such as autoimmune, cholestatic, and hereditary liver diseases has also been made easier by the increasing knowledge and greater accessibility of specific laboratory testing. Finally, despite Egypt's large population, there are more uncommon liver disorders than previously thought. This review article discusses the clinical and epidemiological characteristics of a few uncommon liver disorders and the information currently accessible concerning these illnesses in Egypt.

Cholangiocytes Modulate CD100 Expression in the Liver and Facilitate Pathogenic T-Helper 17 Cell Differentiation

BACKGROUND & AIMS

Chronic inflammation surrounding bile ducts contributes to the disease pathogenesis of most cholangiopathies. Poor efficacy of immunosuppression in these conditions suggests biliary-specific pathologic principles. Here we performed biliary niche specific functional interpretation of a causal mutation (CD100 K849T) of primary sclerosing cholangitis (PSC) to understand related pathogenic mechanisms.

METHODS

Biopsy specimens of explanted livers and endoscopy-guided sampling were used to assess the CD100 expression by spatial transcriptomics, immune imaging, and high-dimensional flow cytometry. To model pathogenic cholangiocyte-immune cell interaction, splenocytes from mutation-specific mice were cocultured with cholangiocytes. Pathogenic pathways were pinpointed by RNA sequencing analysis of cocultured cells and cross-validated in patient materials.

RESULTS

CD100 is mainly expressed by immune cells in the liver and shows a unique pattern around PSC bile ducts with RNA-level colocalization but poor detection at the protein level. This appears to be due to CD100 cleavage as soluble CD100 is increased. Immunophenotyping suggests biliary-infiltrating T cells as the major source of soluble CD100, which is further supported by reduced surface CD100 on T cells and increased metalloproteinases in cholangiocytes after coculturing. Pathogenic T cells that adhered to cholangiocytes up-regulated genes in the T-helper 17 cell differentiation pathway, and the CD100 mutation boosted this process. Consistently, T-helper 17 cells dominate biliary-resident CD4 T cells in patients.

CONCLUSIONS

CD100 exerts its functional impact through cholangiocyte-immune cell cross talk and underscores an active, proinflammatory role of cholangiocytes that can be relevant to novel treatment approaches.

Autoimmune liver diseases and diabetes

Autoimmune liver diseases include autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. They are chronic, heterogenous diseases affecting the liver which is a key metabolic organ that ensures glucose homeostasis. It is well known that patients with other chronic liver diseases such as cirrhosis and nonalcoholic fatty liver disease (NAFLD) display glucose disturbances like insulin resistance and have an increased risk of diabetes. Previous evidence on glucose disturbances in patients with autoimmune liver disease is scarce but does point towards a potentially increased risk of type 1 diabetes and type 2 diabetes. The underlying mechanisms are unknown but may reflect genetic predisposition, concurrent NAFLD and or cirrhosis development, and treatment (steroid) related impairment of glucose homeostasis. Therefore, increased awareness and surveillance of diabetes development in patients with autoimmune liver disease may be important. Overall, detection and treatment of diabetes generally follow the usual diabetes guidelines; however, in patients with advanced liver cirrhosis, HbA1c may not be a reliable marker of average glucose levels, and treatment with insulin is generally recommended. In addition, it has recently been suggested that sodium-glucose cotransporter 2 inhibitors may be beneficial in treating refractory ascites. Further research on diabetes risk in autoimmune liver disease is warranted.

Prolonged administration of a secretin receptor antagonist inhibits biliary senescence and liver fibrosis in Mdr2 -/- mice

BACKGROUND AND AIMS

Secretin (SCT) and secretin receptor (SR, only expressed on cholangiocytes within the liver) play key roles in modulating liver phenotypes. Forkhead box A2 (FoxA2) is required for normal bile duct homeostasis by preventing the excess of cholangiocyte proliferation. Short-term administration of the SR antagonist (SCT 5-27) decreased ductular reaction and liver fibrosis in bile duct ligated and Mdr2 -/- [primary sclerosing cholangitis (PSC), model] mice. We aimed to evaluate the effectiveness and risks of long-term SCT 5-27 treatment in Mdr2 -/- mice.

APPROACH AND RESULTS

In vivo studies were performed in male wild-type and Mdr2 -/- mice treated with saline or SCT 5-27 for 3 months and human samples from late-stage PSC patients and healthy controls. Compared with controls, biliary SCT/SR expression and SCT serum levels increased in Mdr2 -/- mice and late-stage PSC patients. There was a significant increase in ductular reaction, biliary senescence, liver inflammation, angiogenesis, fibrosis, biliary expression of TGF-β1/VEGF-A axis, and biliary phosphorylation of protein kinase A and ERK1/2 in Mdr2 -/- mice. The biliary expression of miR-125b and FoxA2 decreased in Mdr2 -/- compared with wild-type mice, which was reversed by long-term SCT 5-27 treatment. In vitro , SCT 5-27 treatment of a human biliary PSC cell line decreased proliferation and senescence and SR/TGF-β1/VEGF-A axis but increased the expression of miR-125b and FoxA2. Downregulation of FoxA2 prevented SCT 5-27-induced reduction in biliary damage, whereas overexpression of FoxA2 reduced proliferation and senescence in the human PSC cell line.

CONCLUSIONS

Modulating the SCT/SR axis may be critical for managing PSC.

Hepatobiliary Impairments in Patients with Inflammatory Bowel Diseases: The Current Approach

Inflammatory bowel disease (IBD) refers to chronic conditions with a low mortality but high disability. The multisystemic nature of these diseases can explain the appearance of some extraintestinal manifestations, including liver damage. Abnormal liver biochemical tests can be identified in approximately one third of patients with IBD and chronic liver disease in 5% of them. Among the liver diseases associated with IBD are primary sclerosing cholangitis, cholelithiasis, fatty liver disease, hepatic amyloidosis, granulomatous hepatitis, drug-induced liver injury, venous thromboembolism, primary biliary cholangitis, IgG4-related cholangiopathy, autoimmune hepatitis, liver abscesses or the reactivation of viral hepatitis. The most common disease is primary sclerosing cholangitis, a condition diagnosed especially in patients with ulcerative colitis. The progress registered in recent years in the therapeutic management of IBD has not eliminated the risk of drug-induced liver disease. Additionally, the immunosuppression encountered in these patients increases the risk of opportunistic infections, including the reactivation of viral hepatitis. Currently, one of the concerns consists of establishing an efficiency and safety profile of the use of direct-acting antiviral agents (DAA) among patients with hepatitis C and IBD. Early diagnosis and optimal treatment of liver complications can improve the prognoses of these patients.

Extraintestinal Manifestations of Inflammatory Bowel Disease: Current Concepts, Treatment, and Implications for Disease Management

Inflammatory bowel diseases (IBDs) are systemic diseases that manifest not only in the gut and gastrointestinal tract, but also in the extraintestinal organs in many patients. The quality of life for patients with IBD can be substantially affected by these extraintestinal manifestations (EIMs). It is important to have knowledge of the prevalence, pathophysiology, and clinical presentation of EIMs in order to adapt therapeutic options to cover all aspects of IBD. EIMs can occur in up to 24% of patients with IBD before the onset of intestinal symptoms, and need to be recognized to initiate appropriate diagnostic procedures. EIMs most frequently affect joints, skin, or eyes, but can also affect other organs, such as the liver, lung, and pancreas. It is a frequent misconception that a successful therapy of the intestinal inflammation will be sufficient to treat EIMs satisfactorily in most patients with IBD. In general, peripheral arthritis, oral aphthous ulcers, episcleritis, or erythema nodosum can be associated with active intestinal inflammation and can improve on standard treatment of the intestinal inflammation. However, anterior uveitis, ankylosing spondylitis, and primary sclerosing cholangitis usually occur independent of disease flares. This review provides a comprehensive overview of epidemiology, pathophysiology, clinical presentation, and treatment of EIMs in IBD.

Bilateral occlusive retinal vasculitis associated with primary sclerosing cholangitis

We present the case of a 46-year-old man who presented with bilateral panuveitis and occlusive retinal vasculitis 6 months after being acutely admitted with abnormal liver function and diagnosed with primary sclerosing cholangitis (PSC). Initial investigations by the medical and ophthalmic departments including all autoimmune investigations were within normal parameters. Of particular interest was the high likelihood of inadvertent androgenic-anabolic steroid self-suppression of disease. As a lifelong bodybuilder, the patient had been taking oral and intramuscular steroids for years. He became symptomatic upon cessation of these recreational medications. There remains a significant paucity of information describing the relationship between uveitis and PSC. Given the poorly understood aetiology of this rare cholestatic disease, we review the current literature and highlight the diagnostic and therapeutic challenges for such a patient. PSC may predispose patients to an occlusive panuveitis with androgenic-anabolic steroids suppressing ocular autoimmune disease.

Waitlist Mortality and Posttransplant Outcomes in African Americans with Autoimmune Liver Diseases

Background

Liver transplantation is indicated in end-stage liver disease due to autoimmune diseases. The liver allocation system can be affected by disparities such as decreased liver transplant referrals for racial minorities, especially African Americans that negatively impact the pre- and posttransplant outcomes.

Aim

To determine differences in waitlist survival and posttransplant graft survival rates between African American and Caucasian patients with autoimmune liver diseases. Study. The United Network for Organ Sharing database was used to identify all patients with autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis who underwent liver transplant from 1988 to 2019. We compared waitlist survival and posttransplant graft survival between Caucasians and African Americans using Kaplan–Meier curves and Cox regression models. We also evaluated the cumulative incidence of death or delisting for deterioration and posttransplant incidence of death and retransplantation using competing risk analysis.

Results

African Americans were more likely to be removed from the waitlist for death or clinical deterioration (subdistribution hazard ratio (SHR) 1.26, 95% CI 1–1.58, P=0.046) using competing risk analysis. On multivariate Cox regression analysis, there was no difference in posttransplant graft survival among the two groups (hazard ratio (HR) 1.10, 95% CI 0.98–1.23, P=0.081).

Conclusions

Despite the current efforts to reduce racial disparities, we found that African Americans are more likely to die on the waitlist for liver transplant and are less likely to be transplanted, with no differences in graft survival rates. The persistence of healthcare disparities continues to negatively impact African Americans.

A heterozygous germline CD100 mutation in a family with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease without clear etiology or effective treatment. Genetic factors contribute to PSC pathogenesis, but so far, no causative mutation has been found. We performed whole-exome sequencing in a family with autosomal dominant inheritance of PSC and identified a heterozygous germline missense mutation in SEMA4D, encoding a K849T variant of CD100. The mutation was located in an evolutionarily conserved, unstructured cytosolic region of CD100 affecting downstream signaling. It was found to alter the function of CD100-expressing cells with a bias toward the T cell compartment that caused increased proliferation and impaired interferon-γ (IFN-γ) production after stimulation. Homologous mutation knock-in mice developed similar IFN-γ impairment in T cells and were more prone to develop severe cholangitis when exposed to 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet. Transfer of wild-type T cells to knock-in mice before and during DDC exposure attenuated cholangitis. Taken together, we identified an inherited mutation in the disordered cytosolic region of CD100 resulting in T cell functional defects. Our findings suggest a protective role for T cells in PSC that might be used therapeutically.

Recurrent Severe Hepatitis of Autoimmune Origin

The autoimmune liver disease constituent conditions include autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis and IgG-4 associated cholangitis. They remain a diagnostic challenge to the practicing physician due to their close resemblance in clinical course, and laboratory and imaging findings to the vast array of other etiologies of liver injury. We report a case of recurrent severe hepatitis of autoimmune origin in a female patient. The disease course was marked by initial onset at age 39, followed by nearly four years of remission, and a second flare with a more exaggerated severity. Systemic lupus erythematosus was initially deemed as the culprit, however formal diagnostic criteria were not fulfilled and the serological findings were not reproduced at a later date. With the aim of ascertaining the underlying process, the patient underwent an extensive array of testing with regards to infectious, genetic, systemic and autoimmune disease. Positive anti-dsDNA (double stranded DNA) and an antinuclear antibody titer of 1:160 provided the strongest support for an autoimmune etiology, specifically autoimmune hepatitis or possibly an overlap syndrome. An excellent outcome was achieved via treatment with corticosteroids, ursodeoxycholic acid and plasmapheresis.

Cellular therapies for the treatment of immune-mediated GI and liver disease

INTRODUCTION

Immune-mediated liver and gastrointestinal diseases are chronic conditions that lack curative treatments. Despite advances in the understanding and treatment of these conditions, they frequently remain refractory to treatment and represent a significant unmet need. Cellular therapies are an emerging option and hold the potential to have a major impact.

DATA SOURCES

A literature review was carried out using Pubmed. Keywords used for search were 'ATMP', 'immune mediated', 'autoimmune liver disease' and 'immune mediated gastrointestinal conditions', 'cell therapy', 'MSC', 'HSCT', 'Regulatory T cells', 'GVHD', 'Coeliac disease' 'IBD', 'PSC', 'AIH', 'PBC'. No new data were generated or analysed in support of this review.

AREAS OF AGREEMENT

There is substantial evidence from clinical trials to support the use of cell therapies as a treatment for immune-mediated liver and gastrointestinal conditions. Cellular therapy products have the ability to 'reset' the dysregulated immune system and this in turn can offer a longer term remission. There are ongoing clinical trials with mesenchymal stromal cells (MSCs) and other cells to evidence their efficacy profile and fill the gaps in current knowledge. Insights gained will inform future trial designs and subsequent therapeutic applications.

AREAS OF CONTROVERSY

There remains some uncertainty around the extrapolation of results from animal studies to clinical trials. Longevity of the therapeutic effects seen after the use of cell therapy needs to be scrutinized further. Heterogeneity in the selection of cells, source, methods of productions and cell administration pose challenges to the interpretation of the data.

GROWING POINTS

MSCs are emerging as a key therapeutic cells in immune-mediated liver and gastrointestinal conditions. Ongoing trials with these cells will provide new insights and a better understanding thus informing future larger scale studies.

AREAS TIMELY FOR DEVELOPING RESEARCH

Larger scale clinical trials to build on the evidence from small studies regarding safety and efficacy of cellular therapy are still needed before cellular therapies can become off the shelf treatments. Alignment of academia and industry to standardize the processes involved in cell selection, manipulation and expansion and subsequent use in clinical trials is an important avenue to explore further.

Vancomycin prevents fermentable fiber-induced liver cancer in mice with dysbiotic gut microbiota

Owing to their health benefits, dietary fermentable fibers, such as refined inulin, are increasingly fortified in processed foods to enhance their nutritional value. However, we previously demonstrated that when inulin was fed to Toll-like receptor 5 deficient (T5KO) mice susceptible to dysbiosis, a subset of them developed cholestasis and subsequently liver cancer in a gut microbiota-dependent manner. Therefore, we hypothesized that clearance of bacterial taxa, and thereby gut metabolites, involved in the onset and progression to liver cancer could abate the disease in these mice. Such a reshaping of microbiota by vancomycin treatment was sufficient to halt the development of liver cancer in inulin-fed T5KO mice; however, this intervention did not remedy disease penetrance for cholestatic liver injury and its sequelae, including hyperbilirubinemia, hypolipidemia, cholemia and liver fibrosis. Selective depletion of gut bacterial communities was observed in vancomycin-treated mice, including Gram-positive Lachnospiraceae and Ruminococcaceae belonging to the phylum Firmicutes, Bifidobacteria of the phylum Actinobacteria, which ferment fibers, and Clostridium cluster XIVa, which produce secondary bile acids. Lack of liver cancer in vancomycin-treated mice strongly correlated with the substantial loss of secondary bile acids in circulation. Although cholemia was unabated by vancomycin, the composition of serum bile acids shifted toward an abundance of hydrophilic primary bile acids, denoted by the increase in conjugated-to-unconjugated bile acid ratio. Taken together, the present study suggests that microbiotal regulation of bile acid metabolism is one of the critical mediators of fermentable fiber-induced liver cancer in dysbiotic mice.

Is Bartonella a Cause of Primary Sclerosing Cholangitis? A Case Study

The etiology of primary sclerosing cholangitis (PSC) is unknown. I present a case which may be indicative of a causal link between Bartonella infection and PSC. The patient presented with complaints of abdominal pain and bloody diarrhea. A colonoscopy demonstrated chronic inflammation and changes consistent with ulcerative colitis. Routine laboratory studies revealed elevated liver function tests (LFTs); ultrasound and magnetic resonance imaging (MRI) confirmed the diagnosis of PSC. Bartonella serology was positive. It is established that Bartonella infection is associated with both gastrointestinal inflammation and autoimmunity; indeed, there is an animal model for Bartonella-induced PSC. Bartonella is susceptible to treatment with vancomycin and there are case reports and small series that demonstrate that PSC responds to treatment with oral vancomycin. Because of this, it is postulated that at least some cases of PSC may be associated with Bartonella infection. The patient in this report was treated with oral vancomycin and, since then, has been in remission for both colitis and PSC. Since vancomycin is not systemically absorbed, the premise is that he suffered from Bartonella colitis and an autoimmune reaction to Bartonella causing PSC. This premise warrants further study.

Guideline review: British Society of Gastroenterology/UK-PSC guidelines for the diagnosis and management of primary sclerosing cholangitis

New British Society of Gastroenterology/UK-PSC guidelines have recently discussed the current state-of-the-art on primary sclerosing cholangitis and outlined key elements for the management of this disease. The current lack of effective pharmacological treatments to prevent progression of liver fibrosis to cirrhosis limits our ability to modify the natural history of the disease. However, a personalised approach and structured follow-up could allow earlier diagnosis and management of complications and favour access to liver transplantation, which remains the only available treatment. Our commentary overviews the updates and summarises the key recommendations of the recent guidelines for the management of primary sclerosing cholangitis.

Epidemiology, risk of malignancy and patient survival in primary sclerosing cholangitis: a population-based study in Finland

Background: There are only a few and mostly small population-based epidemiological studies of primary sclerosing cholangitis (PSC).Objective: We aimed to estimate prevalence and incidence rates of PSC, and survival and malignancy risk for PSC patients in a large population-based study.Methods: We retrieved 632 PSC patients from 1990 to 2015 in the Hospital District of Helsinki and Uusimaa (HUS), comprising 29% of the Finnish population. Mortality information of the PSC patients was obtained from the national Population Registry, malignancy information from the Finnish Cancer Registry and the causes of death from the Statistics Finland. Standardized incidence ratio and standardized mortality ratio (SMR) were calculated for predefined malignancy types.Results: The crude incidence of PSC in the HUS area was 1.58/100,000 person-years, and the point prevalence in 2015 was 31.7/100,000 inhabitants. The mean time from diagnosis to death was 21.9 years. The risk for any malignancy was three-fold and the risk for colorectal carcinoma was five-fold when comparing with the general population. During the first year after diagnosis of PSC, the risk for cholangiocarcinoma is 900-fold compared to the general population and after that 150-fold. SMR for all malignant neoplasms was 5.9 (95% CI 4.2-8.1).Conclusion: We found that the incidence of PSC in the HUS area in Finland is similar or higher than previously reported from other countries. The prevalence is markedly higher than reported elsewhere, probably due to the active search of the disease, suggesting that the disease is underdiagnosed.

Cholest-4,6-Dien-3-One Promote Epithelial-To-Mesenchymal Transition (EMT) in Biliary Tree Stem/Progenitor Cell Cultures In Vitro

Human biliary tree stem/progenitor cells (hBTSCs), reside in peribiliary glands, are mainly stimulated by primary sclerosing cholangitis (PSC) and cholangiocarcinoma. In these pathologies, hBTSCs displayed epithelial-to-mesenchymal transition (EMT), senescence characteristics, and impaired differentiation. Here, we investigated the effects of cholest-4,6-dien-3-one, an oxysterol involved in cholangiopathies, on hBTSCs biology. hBTSCs were isolated from donor organs, cultured in self-renewal control conditions, differentiated in mature cholangiocytes by specifically tailored medium, or exposed for 10 days to concentration of cholest-4,6-dien-3-one (0.14 mM). Viability, proliferation, senescence, EMT genes expression, telomerase activity, interleukin 6 (IL6) secretion, differentiation capacity, and HDAC6 gene expression were analyzed. Although the effect of cholest-4,6-dien-3-one was not detected on hBTSCs viability, we found a significant increase in cell proliferation, senescence, and IL6 secretion. Interestingly, cholest-4.6-dien-3-one impaired differentiation in mature cholangiocytes and, simultaneously, induced the EMT markers, significantly reduced the telomerase activity, and induced HDAC6 gene expression. Moreover, cholest-4,6-dien-3-one enhanced bone morphogenic protein 4 (Bmp-4) and sonic hedgehog (Shh) pathways in hBTSCs. The same pathways activated by human recombinant proteins induced the expression of EMT markers in hBTSCs. In conclusion, we demonstrated that chronic exposition of cholest-4,6-dien-3-one induced cell proliferation, EMT markers, and senescence in hBTSC, and also impaired the differentiation in mature cholangiocytes.

British Society of Gastroenterology and UK-PSC guidelines for the diagnosis and management of primary sclerosing cholangitis

These guidelines on the management of primary sclerosing cholangitis (PSC) were commissioned by the British Society of Gastroenterology liver section. The guideline writing committee included medical representatives from hepatology and gastroenterology groups as well as patient representatives from PSC Support. The guidelines aim to support general physicians, gastroenterologists and surgeons in managing adults with PSC or those presenting with similar cholangiopathies which may mimic PSC, such as IgG4 sclerosing cholangitis. It also acts as a reference for patients with PSC to help them understand their own management. Quality of evidence is presented using the AGREE II format. Guidance is meant to be used as a reference rather than for rigid protocol-based care as we understand that management of patients often requires individual patient-centred considerations.

Specific Features of Patients With Inflammatory Bowel Disease and Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a chronic and progressive disease of the biliary tract. PSC is strongly associated with inflammatory bowel disease (IBD), mainly with ulcerative colitis, and most PSC patients have underlying IBD. The pathophysiological interactions between IBD and PSC are unclear, although it seems that the patients with IBD and PSC have a distinct phenotype. IBD with coexisting PSC is more extensive and is characterized by milder activity compared to IBD alone. The coexistence of PSC increases the risk for colorectal cancer in IBD patients and lifelong annual surveillance colonoscopy is recommended. Also, liver transplantation (LT) for PSC may affect the course of IBD. In addition, the management of IBD after LT includes many specific problems. On the other hand, the effect of IBD on the natural history of PSC appears to be milder. However, IBD may increase the risk of postsurgical complications after LT and is a risk factor for recurrent PSC after LT. Overall, the coexistence of IBD with PSC changes the management, natural history and prognosis of both diseases.

Duck circovirus induces a new pathogenetic characteristic, primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease of unknown cause. In the study, we found that duck circovirus (DuCV) induces PSC in natural and reproductive cases. PSC in DuCV naturally infected ducks was investigated by PCR and histopathology. A model of PSC was developed in one-day old duck by infection of DuCV. Effects on serum levels of liver enzymes and histology were evaluated, and DuCV tropism for bile duct in liver was analyzed by immuohistochemistry. Pathology observation of natural or reproductive DuCV infected ducks showed that the lesion of liver were characterized by cholangiocytic injuries and progressive fibrous obliteration of the biliary tree associated with lymphocytes infiltration. ALT, AST, ALP, GGT, ALB, TBIL and TP were significantly increased in serum of DuCV infected ducks. DuCV showed higher tropism for epithelial cells of bile duct than other cells in PSC.

Healthy Donor Fecal Microbiota Transplantation for Recurrent Bacterial Cholangitis in Primary Sclerosing Cholangitis - A Single Case Report

Recurrent acute bacterial cholangitis is a unique indication for liver transplantation in primary sclerosing cholangitis. We present the first report on utility of healthy donor fecal transplantation for management of recurrent acute bacterial cholangitis in a primary sclerosing cholangitis patient. We demonstrate the striking liver biochemistry, bile acid and bacterial community changes following intestinal microbiota transplantation associated with amelioration of recurrent cholangitis.

Hepatobiliary Manifestations and Complications in Inflammatory Bowel Disease: A Review

Liver and biliary track diseases are common extraintestinal manifestations of inflammatory bowel disease (IBD), reported both in Crohn’s disease and ulcerative colitis, and may occur at any time during the natural course of the disease. Their etiology is mainly related to pathophysiological changes induced by IBD, and secondary, due to drugs used in IBD. Fatty liver is considered as the most frequent hepatobiliary manifestation in IBD, while primary sclerosing cholangitis (PSC) is the most correlated hepatobiliary disorder and is more prevalent in patients with ulcerative colitis. PSC can cause serious complications from the liver, biliary tree, and gallbladder and can lead to liver failure. Less frequently, IBD-associated hepatobiliary manifestations include cholelithiasis, granulomatous hepatitis, portal vein thrombosis, IgG4-related cholangiopathy, pyogenic liver abscess, hepatic amyloidosis and primary biliary cirrhosis. Most of the drugs used for IBD treatment may cause liver toxicity. Methotrexate and thiopurines carry the higher risk for hepatotoxicity, and in many cases, dose adjustment may normalize the liver biochemical tests. Reactivation of hepatitis B and C virus during immunosuppressive use, especially during use of biological agents, is a major concern, and adequate screening, vaccination and prophylactic treatment is warranted.

Vedolizumab in patients with concurrent primary sclerosing cholangitis and inflammatory bowel disease does not improve liver biochemistry but is safe and effective for the bowel disease

BACKGROUND

Blocking of lymphocyte trafficking to bile ducts is a potential mechanism to alter the disease course of patients with primary sclerosing cholangitis (PSC).

AIM

To describe the effect of the α₄ β₇ integrin antibody, vedolizumab, on liver biochemistry and disease activity in patients with PSC and inflammatory bowel disease (IBD).

METHODS

This is a retrospective multi-centre study of adult patients with a diagnosis of both IBD and PSC. The primary outcome was change in serum alkaline phosphatase level at weeks 14 and 30. Secondary outcomes included changes in other liver biochemistries and in clinical outcomes for the bowel disease. A safety analysis for adverse events was performed.

RESULTS

Thirty-four patients (16 Crohn's disease, 18 ulcerative colitis) were included. Nine (26%) had a history of liver transplant. Median follow-up on vedolizumab was 9 months (IQR: 7-16). There was no overall change in serum alkaline phosphatase level with vedolizumab therapy (median 268 [IQR: 105-551] IU/L at baseline versus 249 [IQR: 183-634] IU/L, P = 0.99 at week 30). No significant changes in other liver biochemistries or the Mayo PSC Risk Score were demonstrated at week 30. Clinical remission was achieved at week 30 in 55% of Crohn's disease and 29% of ulcerative colitis patients. Seven (21%) patients ceased vedolizumab; six patients stopped therapy due to persistent IBD activity and one for worsening of liver biochemistries.

CONCLUSION

Vedolizumab treatment in patients with PSC and IBD did not improve liver biochemistry but was associated with improvement in bowel disease and a favourable safety profile.

Rituximab Induction to Prevent the Recurrence of PSC After Liver Transplantation-The Lessons Learned From ABO-Incompatible Living Donor Liver Transplantation

Background

Multiple studies have failed to reveal an effective method for preventing the recurrence of primary sclerosing cholangitis (PSC) after liver transplantation (LTx). A national study conducted in Japan revealed several risk factors for the recurrence after living donor LTx (LDLTx); however, recipients of ABO-blood type incompatible (ABO-I) LTx were excluded from the previous analysis. In the present study, we investigated the efficacy of an immunosuppressive protocol in ABO-I LTx on the recurrence of PSC after LDLTx.

Methods

We conducted a national survey and analyzed the outcome of recipients who underwent ABO-I LDLTx for PSC (n = 12) between 1994 and 2010 in 9 centers and compared the outcome with that of ABO-compatible LDLTx for PSC (n = 96). The key elements of the immunosuppressive regimen in ABO-I LTx are plasma exchange sessions to remove existing antibodies, and the use of immunosuppression to control humoral immunity. Rituximab was added to the immunosuppression regimen from 2006 onward; 5 patients received rituximab perioperatively.

Results

All 7 recipients who underwent ABO-I LDLTx before 2006 (who did not receive rituximab) died of infection (n = 3), antibody-mediated rejection (n = 1), ABO-incompatibility associated cholangiopathy (n = 1) or recurrence of PSC (n = 2). In contrast, we found that all 5 recipients from 2006 (who were treated with rituximab) retained an excellent graft function for more than 7 years without any recurrence of PSC.

Conclusions

The findings of this study shed light on the efficacy of a novel strategy to prevent the recurrence of PSC and the possible mechanisms provided by rituximab treatment are discussed.

Reciprocal interactions between bile acids and gut microbiota in human liver diseases

The gut microbiota (GM) play a central role in their host's metabolism of bile acids (BAs) by regulating deconjugation, dehydroxylation, dehydrogenation, and epimerization reactions to generate unconjugated free BAs and secondary BAs. These BAs generated by the GM are potent signaling molecules that interact with BA receptors, such as the farnesoid X receptor and Takeda G-protein-coupled receptor 5. Each BA has a differential affinity to these receptors; therefore, alterations in BA composition by GM could modify the intensity of receptor signaling. Bile acids also act as antimicrobial agents by damaging bacterial membranes and as detergents by altering intracellular macromolecular structures. Therefore, BAs and the GM reciprocally control each other's compositions. In this review, we discuss the latest findings on the mutual effects of BAs and GM on each other; we also describe their roles in the pathophysiology of liver disease progression and potential therapeutic applications of targeting this cross-talk.

Bile acids and intestinal microbiota in autoimmune cholestatic liver diseases

Autoimmune cholestatic liver diseases, including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), are manifested as an impairment of normal bile flow and excessive accumulation of potentially toxic bile acids. Endogenous bile acids are involved in the pathogenesis and progression of cholestasis. Consequently, chronic cholestasis affects the expression of bile acid transporters and nuclear receptors, and results in liver injury. Several lines of evidence suggest that intestinal microbiota plays an important role in the etiopathogenesis of cholestatic liver diseases by regulating metabolism and immune responses. However, progression of the disease may also affect the composition of gut microbiota, which in turn exacerbates the progression of cholestasis. In addition, the interaction between intestinal microbiota and bile acids is not unidirectional. Bile acids can shape the gut microbiota community, and in turn, intestinal microbes are able to alter bile acid pool. In general, gut microbiota actively communicates with bile acids, and together play an important role in the pathogenesis of PBC and PSC. Targeting the link between bile acids and intestinal microbiota offers exciting new perspectives for the treatment of those cholestatic liver diseases. This review highlights current understanding of the interactions between bile acids and intestinal microbiota and their roles in autoimmune cholestatic liver diseases. Further, we postulate a bile acids-intestinal microbiota-cholestasis triangle in the pathogenesis of autoimmune cholestatic liver diseases and potential therapeutic strategies by targeting this triangle.

Emerging treatments for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic, idiopathic liver disease that can progress to end-stage liver disease, cirrhosis and cholangiocarcinoma. PSC is an uncommon and highly heterogeneous disease, associated with inflammatory bowel disease and a complex pathophysiology. To date, no medical therapies have proved effective. The only available treatment for end-stage PSC is liver transplant, but recurrence is a significant complication. Areas covered: This review will explore previously tested treatments, discuss current treatment strategies and present viewpoints about future emerging therapies in PSC. We searched PubMed using the noted keywords. We included data from full-text articles published in English. Further relevant articles were identified from the reference lists of review articles. Expert commentary: The development of new therapies in PSC has been challenging. However, with greater awareness of the disease nowadays, new insights into the disease may help in the design of future therapeutic agents in PSC and ultimately in effective therapies.

Antiinflammatory and Hepatoprotective Medicinal Herbs as Potential Substitutes for Bear Bile

Practitioners of traditional Chinese medicine (TCM) commonly prescribe medicinal formulations relying on the purported synergism of a combination of plant species, sometimes incorporating animal parts and minerals. Bear bile, obtained from either wild or farmed bears, is a commonly used constituent of traditional medicine formulations. With several bear species now listed under Convention on International Trade in Endangered Species of Wild Fauna and Flora as threatened with extinction and with bear farming being actively campaigned against on ethical grounds, it is important to seek and promote alternatives to the use of bear bile as medicine. This chapter describes and evaluates the scientific data relating to the efficacy of bear bile and potential alternatives to its use, including the use of bile from other animal species, the use of synthetic chemical alternatives, and the use of herbal substitutes. Scientific studies have confirmed the efficacy of bear bile as an antiinflammatory and a hepatoprotective agent. Ursodeoxycholic acid (UDCA), the active component of bear bile is used in a synthetic form in Western medicine and can serve as an alternative to bear bile in the treatment and management of certain cholestatic liver conditions. In TCM practice, bile from domesticated animal species (such as cattle, chicken, and pig) has been used as a substitute for bear bile. Following evaluation of TCM literature and pharmacological/clinical data, the authors propose six plant species, either as single herbs or in combination, Gardenia jasminoides (zhī zi; ), Scutellaria baicalensis (huáng qín; ), Coptis chinensis (huáng lián, ), Phellodendron amurense (huáng băi; ), Andrographis paniculata (chuan xin lian; ), and Rheum palmatum (dà huang; ), two medicinal Kampo formulations, Orengedokuto, Dia-Orengedokuto (which originated from traditional Chinese herbal formula Huanglian Jiedu Tang, ), and two individual phytochemicals (berberine and andrographolide) as alternatives to bear bile. The proposed herbal alternatives are frequently found listed in traditional formulations also containing bear bile, usually with different therapeutic roles ascribed to them. The existing evidence base for the effectiveness of herbal alternatives is sufficiently strong for TCM practitioners and consumers to consider using these without the addition of bear bile. This consideration is driven by the imperative to protect populations of bears from overexploitation in the wild and when farmed. However, for the identified alternatives to be accepted by users, it is essential that researchers and TCM practitioners collaborate effectively to initiate consumer behavior change.

Impact of Microbes on the Pathogenesis of Primary Biliary Cirrhosis (PBC) and Primary Sclerosing Cholangitis (PSC)

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) represent the major clinical entities of chronic cholestatic liver diseases. Both disorders are characterized by portal inflammation and slowly progress to obliterative fibrosis and eventually liver cirrhosis. Although immune-pathogenic mechanisms have been implicated in the pathogenesis of PBC and PSC, neither disorder is considered to be a classical autoimmune disease, as PSC and PBC patients do not respond to immune-suppressants. Furthermore, the decreased bile flow resulting from the immune-mediated tissue assault and the subsequent accumulation of toxic bile products in PBC and PSC not only perpetuates biliary epithelial damage, but also alters the composition of the intestinal and biliary microbiota and its mutual interactions with the host. Consistent with the close association of PSC and inflammatory bowel disease (IBD), the polyclonal hyper IgM response in PBC and (auto-)antibodies which cross-react to microbial antigens in both diseases, an expansion of individual microbes leads to shifts in the composition of the intestinal or biliary microbiota and a subsequent altered integrity of epithelial layers, promoting microbial translocation. These changes have been implicated in the pathogenesis of both devastating disorders. Thus, we will discuss here these recent findings in the context of novel and alternative therapeutic options.

Elevated cholesterol levels have a poor prognosis in a cholestasis scenario

Cholestasis results from defective bile flow through the biliary ducts leading to the accumulation of bile acids (BAs) in hepatocytes and serum. It has been seen that cholestasis is associated with hypercholesterolemia, which is a prerequisite for gallstone formation and primary biliary cirrhosis, being some of the most common gastrointestinal disorders in Western societies. Cytotoxic BAs induce proinflammatory mediators, oxidative stress, and apoptosis in hepatocytes, whereas cytoprotective BAs prevent them; they can also modify the plasmatic membrane structure of cells or mitochondrial outer membrane properties as well as the distribution of cholesterol, altering various proteins involved in BAs homeostasis.