Minocycline in the treatment of patients with primary sclerosing cholangitis: results of a pilot study

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 pharmacologic therapies for primary sclerosing cholangitis

PURPOSE OF REVIEW

The only currently approved treatment for primary sclerosing cholangitis (PSC) is liver transplantation, with a median time to transplant of 12-18 years after diagnosis. There are a number of emerging drugs that have the potential to meet this critically unmet need that will be summarized and discussed herein.

RECENT FINDINGS

Although the cause of PSC is unknown, there are a number of novel therapeutics under development. These drugs target presumed pathogenic mechanisms largely extrapolated from ex-vivo and in-vivo preclinical models, as well as translational observations.

SUMMARY

Future therapeutic strategies for PSC may include a multitude of complex pathogenic mechanisms encompassing pathways of immunomodulation, the microbiome and inflammation-related fibrosis.

Genetics of primary sclerosing cholangitis and pathophysiological implications

Primary sclerosing cholangitis (PSC) is a chronic disease leading to fibrotic scarring of the intrahepatic and extrahepatic bile ducts, causing considerable morbidity and mortality via the development of cholestatic liver cirrhosis, concurrent IBD and a high risk of bile duct cancer. Expectations have been high that genetic studies would determine key factors in PSC pathogenesis to support the development of effective medical therapies. Through the application of genome-wide association studies, a large number of disease susceptibility genes have been identified. The overall genetic architecture of PSC shares features with both autoimmune diseases and IBD. Strong human leukocyte antigen gene associations, along with several susceptibility genes that are critically involved in T-cell function, support the involvement of adaptive immune responses in disease pathogenesis, and position PSC as an autoimmune disease. In this Review, we survey the developments that have led to these gene discoveries. We also elaborate relevant interpretations of individual gene findings in the context of established disease models in PSC, and propose relevant translational research efforts to pursue novel insights.

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.

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of IgG4-related diseases. Small-duct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor- α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.

Prospective Clinical Trial of Rifaximin Therapy for Patients With Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a rare, chronic, cholestatic liver disease in which emerging data suggest that oral antibiotics may offer therapeutic effects. We enrolled patients with PSC in a 12-week, open-label pilot study to investigate the efficacy and safety of 550 mg of oral rifaximin twice daily. The primary end point was serum alkaline phosphatase (ALK) at 12 weeks. Secondary end points included (1) serum bilirubin, gamma-glutamyl transpeptidase, and Mayo PSC risk score; (2) fatigue impact scale, chronic liver disease questionnaire, and short form health survey (SF-36) scores; and (3) adverse effects (AEs). Analyses were performed with nonparametric tests. Sixteen patients were enrolled, among whom the median age was 40 years; 13 (81%) were male, 13 had inflammatory bowel disease, and baseline ALK was 342 IU/mL (interquartile range, 275-520 IU/mL). After 12 weeks of treatment, there were no significant changes in ALK (median increase of 0.9% to 345 IU/mL; P = 0.47) or any of the secondary biochemical end points (all P > 0.05). Similarly, there were no significant changes in fatigue impact scale, chronic liver disease questionnaire, or SF-36 scores (all P > 0.05). Three patients withdrew from the study due to AEs; 4 others reported mild AEs but completed the study. In conclusion, although some antibiotics may have promise in treating PSC, oral rifaximin, based on the results herein, seems inefficacious for this indication. Future studies are needed to understand how the antimicrobial spectra and other properties of antibiotics might determine their utility in treating PSC.

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.

Surrogate endpoints for clinical trials in primary sclerosing cholangitis: Review and results from an International PSC Study Group consensus process

Primary sclerosing cholangitis (PSC) is a rare, but serious, cholestatic disease for which, to date, no effective therapy exists to halt disease progression toward end-stage liver disease. Clinical trial design to study drugs that improve prognosis is hampered by the relatively low event rate of clinically relevant endpoints. To overcome this shortcoming, there is an urgent need to identify appropriate surrogate endpoints. At present, there are no established surrogate endpoints. This article provides a critical review and describes the results of a consensus process initiated by the International PSC Study Group to delineate appropriate candidate surrogate endpoints at present for clinical trials in this frequently dismal disease. The consensus process resulted in a shortlist of five candidates as surrogate endpoints for measuring disease progression: alkaline phosphatase (ALP); transient elastography (TE); histology; combination of ALP+histology; and bilirubin. Of these, histology, ALP, and TE came out as the most promising. However, the expert panel concluded that no biomarker currently exceeds level 3 validation. Combining multiple endpoints is advisable.

CONCLUSION

At present, there are insufficient data to support level 2 validation for any surrogate endpoint in PSC. Concerted efforts by all stakeholders are highly needed. Novel, promising noninvasive biomarkers are under study and should be incorporated as exploratory endpoints in clinical trials.

Effects of Antibiotics on Gut Microbiota

The gut microbiota influences essential human functions including digestion, energy metabolism, and inflammation by modulating multiple endocrine, neural, and immune pathways of the host. Its composition and complexity varies markedly across individuals and across different sites of the gut, but provides a certain level of resilience against external perturbation. Short-term antibiotic treatment is able to shift the gut microbiota to long-term alternative dysbiotic states, which may promote the development and aggravation of disease. Common features of post-antibiotic dysbiosis include a loss of taxonomic and functional diversity combined with reduced colonization resistance against invading pathogens, which harbors the danger of antimicrobial resistance. This review summarizes the antibiotic-related changes of the gut microbiota and potential consequences in health and disease.

The Gut-Liver Axis in Primary Sclerosing Cholangitis

Dysregulation of the key genetic, immunologic, and microbiome compounds of the gut-liver axis is the basis for inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC). This creates opportunities to accelerate therapies that have been traditionally developed for IBD to be used in PSC to the benefit of both diseases. Shared genetic susceptibility loci has yielded important clues into the pathogenesis of PSC-IBD. Understanding of the critical links between PSC and IBD are essential in designing clinical care pathways for these complex patients.

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

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease that progresses to end-stage liver disease and cirrhosis. Recurrent biliary inflammation is thought to lead to dysplasia, and as such PSC confers a high risk of cholangiocarcinoma. PSC accounts for 10% of all UK liver transplants, although transplantation does not guarantee a cure with 20% recurrence in the graft. At present there are no effective medical treatment options for PSC, and trials of novel therapeutic agents are limited by the time taken to reach clinically significant endpoints with no well defined early surrogate markers for disease outcome. Moreover, PSC appears to be a heterogeneous disease with regards to disease distribution, associated inflammatory bowel disease and subsequent disease outcome, further compounding the issue. Thus existing trials have taken place in heterogeneous groups, are likely to be underpowered to detect any individual subgroups effect. The current mainstay of medical treatment is still with ursodeoxycholic acid, although there is no evidence that it alters long-term outcome. Small pilot studies of immunosuppressive agents have taken place, but despite evidence that may support studies in larger groups, these have not been conducted. Recent advances in our understanding of the disease pathogenesis may therefore pave the way for trials of novel therapeutic agents in PSC, even given the limitations described. This review explores the controversial evidence underlying current treatment strategies and discounted treatments, and explores prospective agents that may bring new hope to the treatment of PSC in the 21st century.

ACG Clinical Guideline: Primary Sclerosing Cholangitis

Primary sclerosing cholangitis is a chronic cholestatic liver disease that can shorten life and may require liver transplantation. The cause is unknown, although it is commonly associated with colitis. There is no approved or proven therapy, although ursodeoxycholic acid is used by many on an empiric basis. Complications including portal hypertension, fat-soluble vitamin deficiency, metabolic bone diseases, and development of cancers of the bile duct or colon can occur.

Current research on the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a progressive disease of the liver characterized by inflammation and destruction of the intra- and/or extra-hepatic bile ducts, leading to fibrosis and ultimately liver failure, cirrhosis and an increased risk of malignancy. The etiology of PSC is unclear. It is often associated with the inflammatory bowel diseases (IBD), particularly Ulcerative Colitis (UC); up to 75% of PSC patients have UC. PSC is more prevalent in men than in women. Ursodeoxycholic acid (UDCA) has been extensively studied in PSC in randomized clinical trials but failed to show a positive impact on the natural course of the disease. Currently, there is no effective medical therapy for PSC, and the majority of patients will eventually require liver transplantation. PSC is one of the leading indications for liver transplantation. In this paper, we review the current research on the potential therapeutic agents for the treatment of PSC.

The liver in pediatric gastrointestinal disease

Hepatic involvement is often encountered in gastrointestinal (GI) diseases, in part because of the close anatomic and physiologic relations between the liver and GI tract. Drainage of the mesenteric blood supply to the portal vein permits absorbed and/or translocated nutrients, toxins, bacterial elements, cytokines, and immunocytes to gain hepatic access. Liver problems in digestive disorders may range from nonspecific hepatocellular enzyme elevations to significant pathologic processes that may progress to end-stage liver disease. Hepatobiliary manifestations of primary GI diseases in childhood and adolescence are not uncommon and include several well-described associations, such as sclerosing cholangitis with inflammatory bowel disease. Liver damage may also result from the effects of drugs used to treat GI diseases, for example, the hepatotoxicity of immunomodulatory therapies. This review highlights the important features of the hepatic and biliary abnormalities associated with 3 common pediatric GI conditions: inflammatory bowel disease, celiac disease, and cystic fibrosis.

Primary sclerosing cholangitis and the microbiota: current knowledge and perspectives on etiopathogenesis and emerging therapies

Primary sclerosing cholangitis (PSC) is a chronic, fibroinflammatory, cholestatic liver disease of unknown etiopathogenesis. PSC generally progresses to liver cirrhosis, is a major risk factor for hepatobiliary and colonic neoplasia, and confers a median survival to death or liver transplantation of only 12 years. Although it is well recognized that approximately 75% of patients with PSC also have inflammatory bowel disease (IBD), the significance of this association remains elusive. Accumulating evidence now suggests a potentially important role for the intestinal microbiota, and enterohepatic circulation of molecules derived therefrom, as a putative mechanistic link between PSC and IBD and a central pathobiological driver of PSC. In this concise review, we provide a summary of and perspectives regarding the relevant basic, translational, and clinical data, which, taken together, encourage further investigation of the role of the microbiota and microbial metabolites in the etiopathogenesis of PSC and as a potential target for novel pharmacotherapies.

Advances and controversies in the pathogenesis and management of primary sclerosing cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a chronic immune-mediated liver disease that results in end-stage liver disease requiring liver transplantation. PSC is closely associated with inflammatory bowel disease (IBD) with 70% of patients with PSC also suffering from IBD.

SOURCES OF DATA

Data for this review were obtained from PubMed.

AREAS OF AGREEMENT

Historical and genome-wide association studies have established a strong human leukocyte antigen (HLA) linkage to PSC and defined specific haplotypes associated with enhanced PSC risk. Fifteen non-HLA loci have been defined in PSC.

AREAS OF CONTROVERSY

The biological role of risk loci in PSC and their place in PSC pathogenesis remain speculative but suggest significant interactions with the host microbiome and therapeutic opportunities.

GROWING POINTS

Genetics provides a platform to systematically target emerging therapies in PSC.

AREAS TIMELY FOR DEVELOPING RESEARCH

Linking PSC genotypes with biology and disease phenotypes paves the way for a personalized medicine approach to manage PSC.

Roux-en-Y choledochojejunostomy versus duct-to-duct biliary anastomosis in liver transplantation for primary sclerosing cholangitis: a meta-analysis

BACKGROUND

Roux-en-Y choledochojejunostomy and duct-to-duct anastomosis are potential methods for biliary reconstruction in liver transplantation (LT) for recipients with primary sclerosing cholangitis (PSC). However, there is controversy over which method yields superior outcomes. The purpose of this study was to evaluate the outcomes of duct-to-duct versus Roux-en-Y biliary anastomosis in patients undergoing LT for PSC.

METHODS

Studies comparing Roux-en-Y versus duct-to-duct anastomosis during LT for PSC were identified based on systematic searches of 9 electronic databases and multiple sources of gray literature.

RESULTS

The search identified 496 citations, including 7 retrospective series, and 692 patients met eligibility criteria. The use of duct-to-duct anastomosis was not associated with a significant difference in clinical outcomes, including 1-year recipient survival rates (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.65-1.60; P = .95), 1-year graft survival rates (OR, 1.11; 95% CI, 0.72-1.71; P = .64), risk of biliary leaks (OR, 1.23; 95% CI, 0.59-2.59; P = .33), risk of biliary strictures (OR, 1.99; 95% CI, 0.98-4.06; P = .06), or rate of recurrence of PSC (OR, 0.94; 95% CI, 0.19-4.78; P = .94).

CONCLUSIONS

There were no significant differences in 1-year recipient survival, 1-year graft survival, risk of biliary complications, and PSC recurrence between Roux-en-Y and duct-to-duct biliary anastomosis in LT for PSC.

Diagnosis and classification of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease of the liver and that is characterized by progressive inflammation, fibrosis, and stricturing of the intrahepatic and extrahepatic bile ducts. It is progressive in most patients and leads to cirrhosis. It is a rare disease, mostly affecting people of northern European descent, males greater than females. The diagnosis is best established by contrast cholangiography, which reveals a characteristic picture of diffuse, multifocal strictures and focal dilation of the bile ducts, leading to a beaded appearance. Inflammatory bowel disease (IBD) is present in ~75% of the patients with PSC, mostly ulcerative colitis (~85% of the cases). In addition to biliary cirrhosis, complications of PSC include dominant strictures of the bile ducts, cholangitis, cholangiocarcinoma, colon dysplasia and cancer in patients with IBD, gallbladder polyps and cancer, and hepatic osteodystrophy. The etiology of PSC is not clear, but studies are ongoing. The median survival without liver transplantation is 12 to 15 years after diagnosis. Currently there are no effective treatments except liver transplantation. Immunosuppressive medications have not been shown to be effective but antibiotics and anti-fibrotic agents seem promising.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is the classic hepatobiliary manifestation of inflammatory bowel disease and is generally chronic and progressive. Patients frequently present with asymptomatic, anicteric cholestasis, but many develop progressive biliary strictures with time, leading to recurrent cholangitis, biliary cirrhosis, and end-stage liver disease. Medical treatment does not slow the progression of disease, and many patients need liver transplantation, after which recurrent disease is a risk. The increased incidence of hepatobiliary cancer, which is not related to the underlying severity of biliary fibrosis, is of particular concern. Risk of colorectal cancer is also increased in patients with coexistent inflammatory bowel disease. Mechanistic insights have arisen from studies of secondary sclerosing cholangitis, in which a similar clinical profile is associated with a specific cause, and genomic studies have elucidated potential disease-initiating pathways in the primary form. The close association between inflammatory bowel disease and primary sclerosing cholangitis underscores the need to further understand the role of environmental factors in generation of lymphocytes that are postulated to be retargeted, deleteriously, to the biliary tree. Treatment of primary sclerosing cholangitis is confined to supportive measures, but advances in pathobiology suggest that new stratified approaches will soon be available.

Role of the microbiota and antibiotics in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an idiopathic, progressive, cholestatic liver disease with considerable morbidity and mortality and no established pharmacotherapy. In addition to the long-recognized association between PSC and inflammatory bowel disease, several lines of preclinical and clinical evidence implicate the microbiota in the etiopathogenesis of PSC. Here we provide a concise review of these data which, taken together, support further investigation of the role of the microbiota and antibiotics in PSC as potential avenues toward elucidating safe and effective pharmacotherapy for patients afflicted by this illness.

Pathogenesis of primary sclerosing cholangitis and advances in diagnosis and management

Primary sclerosing cholangitis (PSC), first described in the mid-1850s, is a complex liver disease that is heterogeneous in its presentation. PSC is characterized by chronic cholestasis associated with chronic inflammation of the biliary epithelium, resulting in multifocal bile duct strictures that can affect the entire biliary tree. Chronic inflammation leads to fibrosis involving the hepatic parenchyma and biliary tree, which can lead to cirrhosis and malignancy. The etiology of PSC is not fully understood, which in part explains the lack of effective medical therapy for this condition. However, we have begun to better understand the molecular pathogenesis of PSC. The recognition of specific clinical subtypes and their pattern of progression could improve phenotypic and genotypic classification of the disease. We review our current understanding of this enigmatic disorder and discuss important topics for future studies.

Update on primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) remains one of the most challenging conditions of clinical hepatology. There has been a steady growth in research to overcome this fact and the present review aims at summarizing the most recently published literature. The main emphasis will be put on the link of recent pathogenetic insights to clinical characteristics and patient management. With regard to pathogenesis, there is no consensus yet as to whether immune mediated injury or factors related to bile acid physiology are the most important. It also remains to be clarified whether PSC is a mixed bag of various secondary etiologies yet to be defined, or a disease entity predominantly represented by sclerosing cholangitis in the context of inflammatory bowel disease. Most important, there is no available medical therapy with proven influence on clinical end points, and timing of liver transplantation and patient follow-up are challenging due to the unpredictable and high risk of cholangiocarcinoma.

Treatment of autoimmune liver disease: current and future therapeutic options

Autoimmune liver disease spans three predominant processes, from the interface hepatitis of autoimmune hepatitis to the lymphocytic cholangitis of primary biliary cirrhosis, and finally the obstructive fibrosing sclerotic cholangiopathy of primary sclerosing cholangitis. Although all autoimmune in origin, they differ in their epidemiology, presentation and response to immunosuppressive therapy and bile acid based treatments. With an ongoing better appreciation of disease aetiology and pathogenesis, treatment is set ultimately to become more rational. We provide an overview of current and future therapies for patients with autoimmune liver disease, with an emphasis placed on some of the evidence that drives current practice.

Randomised clinical trial: vancomycin or metronidazole in patients with primary sclerosing cholangitis - a pilot study

BACKGROUND

Emerging data suggest that oral antibiotics may have therapeutic effects in primary sclerosing cholangitis (PSC), but published studies are limited.

AIMS

To investigate the safety and efficacy of oral vancomycin and metronidazole in patients with PSC.

METHODS

Thirty-five patients with PSC were randomised in a double-blind manner into four groups: vancomycin 125 mg or 250 mg four times/day, or metronidazole 250 mg or 500 mg three times/day for 12 weeks. The primary endpoint was decrease in alkaline phosphatase (ALK) at 12 weeks. Secondary end points included serum bilirubin and Mayo PSC risk score; pruritus; and adverse effects (AEs). Nonparametric tests were used for analysis.

RESULTS

The primary endpoint was reached in the low-dose (-43% change in ALK, P = 0.03) and high-dose (-40%, P = 0.02) vancomycin groups, with two patients in the former experiencing ALK normalisation. Bilirubin decreased significantly in the low-dose metronidazole group (-20%, P = 0.03) and trended towards significance in the low-dose vancomycin group (-33%, P = 0.06). Mayo PSC risk score decreased significantly in the low-dose vancomycin (-0.55, P = 0.02) and low-dose metronidazole group (-0.16, P = 0.03). Pruritus decreased significantly in the high-dose metronidazole group (-3.4, P = 0.03). AEs led to medication discontinuation in six patients, four of whom were receiving metronidazole.

CONCLUSIONS

Both vancomycin and metronidazole demonstrated efficacy; however, only patients in the vancomycin groups reached the primary endpoint, and with less adverse effects. Larger, longer-term studies are needed to further examine the safety and efficacy of antibiotics as a potential treatment for patients with primary sclerosing cholangitis (clinicaltrials.gov NCT01085760).

Primary sclerosing cholangitis: a review and update on therapeutic developments

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic, idiopathic liver disease characterized by fibro-obliterative inflammation of the hepatic bile ducts. In a clinically significant proportion of patients, PSC progresses to cirrhosis, end-stage liver disease, and in some cases, cholangiocarcinoma. Despite clinical trials of nearly 20 different pharmacotherapies over several decades, safe and effective medical therapy, albeit critically needed, remains to be established. PSC is pathogenically complex, with genetic, immune, enteric microbial, environmental and other factors being potentially involved and, thus, not surprisingly, it manifests as a clinically heterogeneous disease with a relatively unpredictable course. It is likely that this complexity and clinical heterogeneity are responsible for the negative results of clinical trials, but novel insights about and approaches to PSC may shift this trend. The authors herein provide a review of previously tested pharmacologic agents, discuss emerging fundamental concepts and present viewpoints regarding how identifying therapies for PSC may evolve over the next several years.

Current pharmacotherapy for cholestatic liver disease

IMPORTANCE OF THE FIELD

The cholestatic liver diseases comprise a heterogeneous group of disorders which, left untreated, usually progresses to cirrhosis and liver failure. Most are recognized before the onset of advanced fibrosis, thereby affording an opportunity for disease modifying therapy.

AREAS COVERED

This review will cover the current pharmacologic management of the most common causes of cholestatic liver disease in adults, including primary biliary cirrhosis, primary biliary cirrhosis-autoimmune hepatitis overlap syndrome, primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, intestinal failure-associated liver disease, and immunoglobulin G4-associated cholangitis. Pharmacologic management of complications of cholestasis will also be reviewed.

EXPERT OPINION

Effective therapy for most cholestatic liver disease is lacking. Ursodeoxycholic acid (UDCA) slows the progression of primary biliary cirrhosis but the majority of patients do not have a full response. Even in those with a complete response, UDCA does not cure the disease. There is currently no effective medical therapy for primary sclerosing cholangitis. Symptoms and serum liver biochemistry values in intrahepatic cholestasis of pregnancy are improved with UDCA, but it is not certain if this alters the course of disease. Immunoglobulin G4-associated cholangitis is responsive to steroids but may relapse. The farnesoid X receptor agonists are a promising new class of drugs currently being tested in cholestatic liver disease.

Management of primary sclerosing cholangitis: conventions and controversies

Primary sclerosing cholangitis (PSC) is a chronic inflammatory cholangiopathy that results in fibrotic strictures and dilations of the intra- and extrahepatic bile ducts. PSC is uncommon, occurs predominantly in males and has a strong association with inflammatory bowel disease. While the pathogenesis of PSC has not been fully elucidated, emerging evidence supports roles for the innate and adaptive immune systems, and genome-wide analyses have identified several genetic associations. Using the best available evidence, the present review summarizes the current understanding of the diagnosis, pathogenesis and management of PSC. Despite its rarity, there is an urgent need for collaborative research efforts to advance therapeutic options for PSC beyond liver transplantation.

Primary sclerosing cholangitis: is any treatment worthwhile?

While many therapeutic agents have been evaluated in Primary Sclerosing Cholangitis (PSC), none have been shown in controlled trials to modify the course of disease. The bile acid ursodeoxycholic acid (UDCA) has been widely used in the treatment of PSC but its use remains controversial. It may have a role in providing chemoprotection against the development of colonic dysplasia/cancer in patients with associated inflammatory bowel disease. The exclusion of IgG4-associated cholangitis, which generally responds to immunosuppressant agents, is essential prior to deciding on an appropriate therapeutic strategy in PSC. In the absence of proven therapeutic agents, treatment strategies are usually aimed at minimizing the complications of the biliary disease. Endoscopic management of dominant strictures may improve long-term outcomes. Orthotopic liver transplantation has a good outcome in patients with end stage PSC.

Antibiotics for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease that is associated with considerable morbidity and mortality. The disease etiopathogenesis has not been well defined. Several observations suggest that portal bacteremia or chronic bile duct infection may be factors that could play a role in the pathogenesis of the disease. Clinical trials have tested different treatments for PSC but without convincing evidence of benefit. Liver transplantation is the only available therapeutic option that is thought to be beneficial for PSC. Antibiotics have been used in several case series over the years to treat PSC and have had, in some cases, impressive benefits when compared with other drugs used for treating the disease. We gathered the available data for different antibiotics used in PSC in this review. Further studies are needed to support the efficacy of using antibiotics for PSC patients.

Medical and endoscopic therapy of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease mainly affecting young male patients. PSC is characterised by chronic inflammation and fibrotic strictures of the intra- and extrahepatic biliary system, which eventually lead to cholestasis and biliary cirrhosis. However, the clinical course remains very variable. As the aetiology remains unknown, the development of a causative treatment is challenging and today no specific medical therapy is available. Ursodeoxycholic acid has been widely used for the treatment of PSC, but improved only biochemistry and/or symptoms in low- or medium dosages and is probably harmful in higher dosages. Other drugs such as immunosuppressive, antifibrotic or antibiotic agents have not been proven to be effective in large clinical trials. The endoscopic therapy encompasses balloon-dilatation and/or stenting of strictures, relieves clinical symptoms and improves a cholestatic enzyme profile. However, endoscopic therapy is limited to patients in advanced stages of PSC with biliary obstruction.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic liver condition which may affect both intra and extrahepatic biliary tree. Etiology of PSC remains to be fully elucidated but genetic, autoimmune, inflammatory and possibly infective factors could all contribute to its development. More than two-thirds of patients are males and the most commonly associated condition is an inflammatory bowel disease which occurs in up to 70% of affected subjects. Endoscopic cholangiopancreatography (ERCP) and magnetic resonanse cholangiopancreatography (MRCP) remain a gold standard in the diagnosis of this condition. No curative treatment of PSC exists and a proportion of patients who develop liver failure or suffer from recurrent episodes of cholangitis requires liver transplantation. PSC is associated with increased risk of malignancies, in particular cholangiocarcinoma which may arise in 12% of patients. The main aim of this chapter is to review the current knowledge on pathogenesis and clinical aspects of PSC as well as its associated malignancies.

Systematic review: management options for primary sclerosing cholangitis and its variant forms - IgG4-associated cholangitis and overlap with autoimmune hepatitis

BACKGROUND

Primary sclerosing cholangitis (PSC) remains a challenging disease to manage. The main goals are prevention of disease progression and reduction of the increased cancer risk.

AIMS

To review the management strategies for PSC and its variant forms based on published studies.

METHODS

Publications were identified using Pubmed, Medline and Ovid search engines.

RESULTS

Distinguishing PSC from variants, such as IgG4-associated cholangitis, and overlap with autoimmune hepatitis is essential to guide treatment decisions. There is no proven efficacious medical treatment for PSC. Ursodeoxycholic acid has been disappointing in low and moderate doses, and potentially dangerous in higher doses, although its role and optimal dose in chemoprevention requires investigation. The novel bile acid, 24-norursodeoxycholic acid, has shown promise in mouse models; human trials are in progress. Dominant strictures are optimally managed by dilatation and stenting to relieve obstructive complications, although exclusion of biliary malignancy is essential. Liver transplantation is the only proven therapy for those with advanced disease. Cholangiocarcinoma remains the most unpredictable and feared complication. In highly selected groups, neo-adjuvant chemoradiation with liver transplantation seems promising, but requires further validation. Screening for inflammatory bowel disease and surveillance for colorectal carcinoma should not be overlooked.

CONCLUSIONS

The effective management of PSC and its variants is hindered by uncertainties regarding pathogenesis of disease and factors responsible for its progression. Genome studies may help to identify further targets for drug therapy and factors leading to malignant transformation.

Current management of primary sclerosing cholangitis in pediatric patients

Primary sclerosing cholangitis (PSC) is a chronic cholestatic condition affecting the extrahepatic and intrahepatic biliary tree. The incidence is seemingly increasing in children as a result of increased use of cholangiographic screening techniques in children with inflammatory bowel disease. The clinical presentation of PSC in childhood is variable and frequently without obvious cholestatic features, and cholangiography is essential for the diagnosis of this disorder. Histologic findings may help to exclude autoimmune sclerosing cholangitis. The underlying pathogenesis remains poorly understood and, as a result, therapeutic agents that halt disease progression and improve prognosis are lacking. PSC treatment is mainly supportive and directed at controlling cholestatic symptoms and preventing complications. Ursodeoxycholic acid is helpful in inducing biochemical improvement; long-term pediatric studies to determine a benefit of this agent in young patients are lacking, although results from adult studies have not been promising. Some agents such as antibiotics are under investigation with some promising results. Liver transplantation is required for children who progress to end-stage liver disease. Prospective multicenter trials in children with PSC are needed.

Treatment options for primary sclerosing cholangitis

Primary sclerosing cholangitis is a cholestatic liver disease characterized by inflammation and fibrosis of intra-/extrahepatic bile ducts, leading to multifocal strictures. Primary sclerosing cholangitis exhibits a progressive course resulting in cirrhosis and the need for liver transplantation over a median period of 12 years. The disease is frequently associated with inflammatory bowel disease and carries an increased risk of colorectal cancer and cholangiocarcinoma. Despite extensive research, there is currently no effective medical treatment. Multiple drugs are shown to be ineffective in halting disease progression, including ursodeoxycholic acid, the most widely evaluated drug. High-dose ursodeoxycholic acid (28-30 mg/kg/day) was recently shown to increase the adverse events rate. Endoscopic or radiological dilatation of a 'dominant' stricture may lead to symptomatic and biochemical improvement. However, liver transplantation is the only life-prolonging treatment for patients with end-stage disease. Studies with promising drugs, such as antibiotics, antifibrotic agents and bile acid derivatives, are eagerly awaited.

Endoscopic retrograde cholangiopancreatography in diagnosis and treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis is characterized by progressive fibrosing obliteration of the biliary tract. In some cases the disease is restricted to the small bile ducts, but most patients develop fibrotic stenoses of the larger bile ducts. Despite advances in magnetic resonance cholangiography, in unclear cases endoscopic retrograde cholangiography is necessary to make the correct diagnosis. In patients with total or subtotal strictures of the large bile ducts, these so-called dominant stenoses may be treated by endoscopic balloon dilatation and/or stent placement, though in the large majority of cases a stent placement is not necessary. Several studies showed an improvement of biochemical parameters after endoscopic treatment, and actuarial survival in these patients was improved compared with predicted survival. Endoscopic retrograde cholangiography allows tissue sampling, brush cytology, and bile analysis for early detection of cholangiocarcinoma, a major complication of primary sclerosing cholangitis. Despite successful endoscopic opening of bile duct stenoses, patients often progress to liver failure, leading to liver transplantation as the treatment of choice.

Latest and emerging therapies for primary biliary cirrhosis and primary sclerosing cholangitis

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are the two most common causes of chronic cholestatic liver disease in adults. In PBC, therapy with ursodeoxycholic acid (UDCA) is safe and has been associated with tangible biochemical, histologic, and survival benefits. However, a need for different or adjuvant therapies remains for specific subsets of PBC patients, including those who do not respond to UDCA and those who have advanced histologic disease at presentation. Similarly, beneficial therapies for disease-related symptoms that do not typically respond to UDCA (eg, fatigue and pruritus) are still needed. In contrast to PBC, no medical therapy of proven benefit has been identified for patients with PSC. In PBC and PSC, adequate management of complications of chronic cholestasis is important. For both diseases, liver transplantation is the only curative option.