Effect of high-dose ursodeoxycholic acid on its biliary enrichment in primary sclerosing cholangitis

The gut microbiota-bile acid axis in cholestatic liver disease

Cholestatic liver diseases (CLD) are characterized by impaired normal bile flow, culminating in excessive accumulation of toxic bile acids. The majority of patients with CLD ultimately progress to liver cirrhosis and hepatic failure, necessitating liver transplantation due to the lack of effective treatment. Recent investigations have underscored the pivotal role of the gut microbiota-bile acid axis in the progression of hepatic fibrosis via various pathways. The obstruction of bile drainage can induce gut microbiota dysbiosis and disrupt the intestinal mucosal barrier, leading to bacteria translocation. The microbial translocation activates the immune response and promotes liver fibrosis progression. The identification of therapeutic targets for modulating the gut microbiota-bile acid axis represents a promising strategy to ameliorate or perhaps reverse liver fibrosis in CLD. This review focuses on the mechanisms in the gut microbiota-bile acids axis in CLD and highlights potential therapeutic targets, aiming to lay a foundation for innovative treatment approaches.

Bile Acids: Major Regulator of the Gut Microbiome

Bile acids are synthesized from cholesterol and play an important role in regulating intestinal microflora. The different degrees of hydrophobicity and acidity of individual bile acids may affect their antimicrobial properties. We examined the antimicrobial effects of different bile acids on various microorganisms in vitro and confirmed whether these remain consistent in vivo. Using human bile acids, including ursodeoxycholic acid, cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid, a disc diffusion test was performed, and a rodent model was created to determine the antimicrobial effects of each bile acid. The fecal bacterial population was analyzed using a real-time polymerase chain reaction. Each bile acid showed different microbial inhibitory properties. The inhibitory activity of bile acids against microbiota which normally resides in the gastrointestinal tract and biliary system, was low; however, normal flora of other organs was significantly inhibited. Changes in microbial counts after bile acid administration in a rodent model differed in the colon and cecum. The in vivo and in vitro results show that the antimicrobial effects of bile acids against intestinal microbiota were similar. In conclusion, bile acids could be a novel treatment strategy to regulate gut microbiota.

Emerging therapies in primary sclerosing cholangitis: pathophysiological basis and clinical opportunities

Primary sclerosing cholangitis (PSC) is a progressive liver disease, histologically characterized by inflammation and fibrosis of the bile ducts, and clinically leading to multi-focal biliary strictures and with time cirrhosis and liver failure. Patients bear a significant risk of cholangiocarcinoma and colorectal cancer, and frequently have concomitant inflammatory bowel disease and autoimmune disease manifestations. To date, no medical therapy has proven significant impact on clinical outcomes and most patients ultimately need liver transplantation. Several treatment strategies have failed in the past and whilst prescription of ursodeoxycholic acid (UDCA) prevails, controversy regarding benefits remains. Lack of statistical power, slow and variable disease progression, lack of surrogate biomarkers for disease severity and other challenges in trial design serve as critical obstacles in the development of effective therapy. Advances in our understanding of PSC pathogenesis and biliary physiology over recent years has however led to a surge of clinical trials targeting various mechanistic compartments and currently raising hopes for imminent changes in patient management. Here, in light of pathophysiology, we outline and critically evaluate emerging treatment strategies in PSC, as tested in recent or ongoing phase II and III trials, stratified per a triad of targets of nuclear and membrane receptors regulating bile acid metabolism, immune modulators, and effects on the gut microbiome. Furthermore, we revisit the UDCA trials of the past and critically discuss relevant aspects of clinical trial design, including how the choice of endpoints, alkaline phosphatase in particular, may affect the future path to novel, effective PSC therapeutics.

A Prospective Trial of Withdrawal and Reinstitution of Ursodeoxycholic Acid in Pediatric Primary Sclerosing Cholangitis

Ursodeoxycholic acid (UDCA) is commonly used to treat several liver disorders in adults and children, including primary sclerosing cholangitis (PSC) for which it is not U.S. Food and Drug Administration approved. UDCA treatment has an uncertain impact on disease outcomes and has been reported in high doses to be associated with worse outcome in adults with PSC. In this context, controlled withdrawal and reintroduction of UDCA in children with PSC were studied. Prior to study initiation, participants were required to have alanine aminotransferase (ALT) and gamma‐glutamyl transpeptidase (GGT) <2 times the upper limit of normal on stable UDCA dosing. The study included four phases: I (stable dosing), II (50% UDCA reduction), III (UDCA discontinuation), IV (UDCA reintroduction), with a primary endpoint of change in ALT and GGT between phases I and III. We enrolled 27 participants (22 completed) between March 2011 and June 2016. Changes in mean ALT and GGT between phases I and III were ALT, +29.5 IU/L (P = 0.105) and GGT, +60.4 IU/L (P = 0.003). In 7 participants, ALT and GGT ≤29 IU/L did not rise above 29 IU/L (null response group). Eight participants had increases of ALT or GGT >100 IU/L (flare group). None developed elevated bilirubin. All flares responded to UDCA reinstitution. Serum GGT, interleukin‐8, and tumor necrosis factor α levels were higher in the flare group at baseline. Liver biochemistries increased in children with PSC during controlled UDCA withdrawal; one third increased above 100 IU/L and one third remained normal during UDCA withdrawal. Conclusion: The impact of prolonged UDCA use in childhood PSC and the significance of a biochemical flare are unclear. Further studies of the natural history and treatment of pediatric PSC and UDCA use are needed.

The human gallbladder microbiome is related to the physiological state and the biliary metabolic profile

BACKGROUND

The microbial populations of the human intestinal tract and their relationship to specific diseases have been extensively studied during the last decade. However, the characterization of the human bile microbiota as a whole has been hampered by difficulties in accessing biological samples and the lack of adequate methodologies to assess molecular studies. Although a few reports have described the biliary microbiota in some hepatobiliary diseases, the bile microbiota of healthy individuals has not been described. With this in mind, the goal of the present study was to generate fundamental knowledge on the composition and activity of the human bile microbiota, as well as establishing its potential relationship with human bile-related disorders.

RESULTS

Human bile samples from the gallbladder of individuals from a control group, without any record of hepatobiliary disorder, were obtained from liver donors during liver transplantation surgery. A bile DNA extraction method was optimized together with a quantitative PCR (qPCR) assay for determining the bacterial load. This allows the selection of samples to perform functional metagenomic analysis. Bile samples from the gallbladder of individuals suffering from lithiasis were collected during gallbladder resection and the microbial profiles assessed, using a 16S rRNA gene-based sequencing analysis, and compared with those of the control group. Additionally, the metabolic profile of the samples was analyzed by nuclear magnetic resonance (NMR). We detected, for the first time, bacterial communities in gallbladder samples of individuals without any hepatobiliary pathology. In the biliary microecosystem, the main bacterial phyla were represented by Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. Significant differences in the relative abundance of different taxa of both groups were found. Sequences belonging to the family Propionibacteriaceae were more abundant in bile samples from control subjects; meanwhile, in patients with cholelithiasis members of the families Bacteroidaceae, Prevotellaceae, Porphyromonadaceae, and Veillonellaceae were more frequently detected. Furthermore, the metabolomics analysis showed that the two study groups have different metabolic profiles.

CONCLUSIONS

Our results indicate that the gallbladder of human individuals, without diagnosed hepatobiliary pathology, harbors a microbial ecosystem that is described for the first time in this study. Its bacterial representatives and metabolites are different from those detected in people suffering from cholelithiasis. In this regard, since liver donors have been subjected to the specific conditions of the hospital's intensive care unit, including an antibiotic treatment, we must be cautious in stating that their bile samples contain a physiologically normal biliary microbiome. In any case, our results open up new possibilities to discover bacterial functions in a microbial ecosystem that has not previously been explored.

UDCA, NorUDCA, and TUDCA in Liver Diseases: A Review of Their Mechanisms of Action and Clinical Applications

Bile acids (BAs) are key molecules in generating bile flow, which is an essential function of the liver. In the last decades, there have been great advances in the understanding of BA physiology, and new insights have emerged regarding the role of BAs in determining cell damage and death in several liver diseases. This new knowledge has helped to better delineate the pathophysiology of cholestasis and the adaptive responses of hepatocytes to cholestatic liver injury as well as of the mechanisms of injury of biliary epithelia. In this context, therapeutic approaches for liver diseases using hydrophilic BA (i.e., ursodeoxycholic acid, tauroursodeoxycholic, and, more recently, norursodeoxycholic acid), have been revamped. In the present review, we summarize current experimental and clinical data regarding these BAs and its role in the treatment of certain liver diseases.

Long-Term Ursodeoxycholic Acid Therapy Does Not Alter Lithocholic Acid Levels in Patients with Cystic Fibrosis with Associated Liver Disease

OBJECTIVE

To evaluate the fasting and postprandial serum bile acid composition in patients with cystic fibrosis-associated liver disease (CFLD) after chronic administration of ursodeoxycholic acid (UDCA) (20 mg/kg/day). The aim was to specifically focus on the extent of biotransformation of UDCA to its hepatotoxic metabolite, lithocholic acid, because of recent concerns regarding the safety of long-term, high-dose UDCA treatment for CFLD.

STUDY DESIGN

Twenty patients with CFLD (median age 16 years, range: 2.4-35.0) prescribed UDCA therapy for at least 2 years were studied. Total and individual serum bile acids were measured by stable-isotope dilution mass spectrometry, in fasting and 2-hour postprandial samples taken during chronic UDCA (20 mg/kg/day) administration.

RESULTS

During chronic UDCA administration (median duration 8 years, IQR: 6-16), UDCA became the predominant serum bile acid in all patients (median, IQR: 3.17, 1.25-5.56 μmol/L) and chenodeoxycholic acid concentrations were greater than cholic acid (1.86, 1.00-4.70 μmol/L vs 0.40, 0.24-2.71 μmol/L). The secondary bile acids, deoxycholate and lithocholate, were present in very low concentrations in fasted serum (<0.05 μmol/L). After UDCA administration, 2-hour postprandial concentrations of both UDCA and chenodeoxycholic acid significantly increased (P < .01), but no significant changes in serum lithocholic acid concentrations were observed.

CONCLUSION

These data do not support recent suggestions that enhanced biotransformation of UDCA to the hepatotoxic secondary bile acid lithocholic occurs when patients with CFLD are treated with relatively high doses of UDCA.

Ursodeoxycholic acid inhibits hepatic cystogenesis in experimental models of polycystic liver disease

BACKGROUND & AIMS

Polycystic liver diseases (PLDs) are genetic disorders characterized by progressive biliary cystogenesis. Current therapies show short-term and/or modest beneficial effects. Cystic cholangiocytes hyperproliferate as a consequence of diminished intracellular calcium levels ([Ca(2+)]i). Here, the therapeutic value of ursodeoxycholic acid (UDCA) was investigated.

METHODS

Effect of UDCA was examined in vitro and in polycystic (PCK) rats. Hepatic cystogenesis and fibrosis, and the bile acid (BA) content were evaluated from the liver, bile, serum, and kidneys by HPLC-MS/MS.

RESULTS

Chronic treatment of PCK rats with UDCA inhibits hepatic cystogenesis and fibrosis, and improves their motor behaviour. As compared to wild-type animals, PCK rats show increased BA concentration ([BA]) in liver, similar hepatic Cyp7a1 mRNA levels, and diminished [BA] in bile. Likewise, [BA] is increased in cystic fluid of PLD patients compared to their matched serum levels. In PCK rats, UDCA decreases the intrahepatic accumulation of cytotoxic BA, normalizes their diminished [BA] in bile, increases the BA secretion in bile and diminishes the increased [BA] in kidneys. In vitro, UDCA inhibits the hyperproliferation of polycystic human cholangiocytes via a PI3K/AKT/MEK/ERK1/2-dependent mechanism without affecting apoptosis. Finally, the presence of glycodeoxycholic acid promotes the proliferation of polycystic human cholangiocytes, which is inhibited by both UDCA and tauro-UDCA.

CONCLUSIONS

UDCA was able to halt the liver disease of a rat model of PLD through inhibiting cystic cholangiocyte hyperproliferation and decreasing the levels of cytotoxic BA species in the liver, which suggests the use of UDCA as a potential therapeutic tool for PLD patients.

Prospective evaluation of ursodeoxycholic acid withdrawal in patients with primary sclerosing cholangitis

Ursodeoxycholic acid (UDCA) is no longer recommended for management of adult patients with primary sclerosing cholangitis (PSC). We undertook a prospective evaluation of UDCA withdrawal in a group of consecutive patients with PSC. Twenty six patients, all treated with UDCA (dose range: 10-15 mg/kg/day) were included. Paired blood samples for liver biochemistry, bile acids, and fibroblast growth factor 19 (FGF19) were collected before UDCA withdrawal and 3 months later. Liquid chromatography/tandem mass spectrometry was used for quantification of 29 plasma bile acid metabolites. Pruritus and health-related quality of life (HRQoL) were assessed with a 10-point numeric rating scale, the Medical Outcomes Study Short Form-36 (SF-36), and PBC-40 questionnaires. UDCA withdrawal resulted in a significant deterioration in liver biochemistry (increase of alkaline phosphatase of 75.6%; P<0.0001; gamma-glutamyl transpeptidase of 117.9%, P<0.0001; bilirubin of 50.0%, P<0.001; alanine aminotransferase of 63.9%, P<0.005; and aspartate aminotransferase of 45.0%, P<0.005) and increase of Mayo Risk Score for PSC (change from baseline of +0.5 point; P<0.003). Bile acid analysis revealed a significant decrease in lithocholic acid and its derivatives after UDCA withdrawal, but no effect on concentrations of primary bile acids aside from an increased accumulation of their taurine conjugates. After UDCA removal cholestatic parameters, taurine species of cholic acid and chenodeoxycholic acid correlated with serum FGF19 levels. No significant effect on HRQoL after UDCA withdrawal was observed; however, 42% of patients reported a deterioration in their pruritus.

CONCLUSION

At 3 months, discontinuation of UDCA in patients with PSC causes significant deterioration in liver biochemistry and influences concentrations of bile acid metabolites. A proportion of patients report increased pruritus, but other short-term markers of quality of life are unaffected.

Chemoprevention of esophageal adenocarcinoma in a rat model by ursodeoxycholic acid

Reflux of bile acid into the esophagus induces esophagitis, inflammation-stimulated hyperplasia, metaplasia such as Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC). Caudal-type homeobox 2 (Cdx2) via nuclear factor (NF)-κB induced by bile acid is an important factor in the development of BE and EAC. In colorectal cancer, experimental data suggest a chemopreventive effect of ursodeoxycholic acid (UDCA). We hypothesized that UDCA may protect against the esophageal inflammation-metaplasia-carcinoma sequence by decreasing the overall proportion of the toxic bile acids. Wistar male rats that underwent a duodenoesophageal reflux procedure were divided into two groups. One group was given commercial chow (control group), and the other was given experimental chow containing UDCA (UDCA group). The animals were killed at 40 weeks after surgery, and their bile and esophagus were examined. In the UDCA group, the esophagitis was milder and the incidence of BE was significantly lower (p < 0.05) than in the control group, and EAC was not observed (p < 0.05). In analysis of the compartment of bile acid, UDCA was markedly increased in the UDCA group compared with the control group (32.7 ± 11.4 vs. 0.82 ± 0.33 mmol/L, p < 0.05) and cholic acid was decreased (32.7 ± 4.05 vs. 60.9 ± 8.26 mmol/L, p < 0.05). Expression intensity of Cdx2 and NF-κB was greater in the control group than in the UDCA group (p < 0.05). UDCA may be a chemopreventive agent against EAC by varying the bile acid composition.

Review article: controversies in the management of primary biliary cirrhosis and primary sclerosing cholangitis

BACKGROUND

Despite considerable advances over the last two decades in the molecular understanding of cholestasis and cholestatic liver disease, little improvement has been made in diagnostic tools and therapeutic strategies.

AIMS

To critically review controversial aspects of the scientific basis for common clinical practice in primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) and to discuss key ongoing challenges to improve patient management.

METHODS

We performed a literature search using PubMed and by examining the reference lists of relevant review articles related to the clinical management of PBC and PSC. Articles were considered on the background of the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD) practice guidelines and clinical experience of the authors.

RESULTS

Ongoing challenges in PBC mainly pertain to the improvement of medical therapy, particularly for patients with a suboptimal response to ursodeoxycholic acid. In PSC, development of medical therapies and sensitive screening protocols for cholangiocarcinoma represent areas of intense research. To rationally improve patient management, a better understanding of pathogenesis, including complications like pruritis and fatigue, is needed and there is a need to identify biomarker end-points for treatment effect and prognosis. Timing of liver transplantation and determining optimal regimens of immunosuppression post-liver transplantation will also benefit from better appreciation of pre-transplant disease mechanisms.

CONCLUSION

Controversies in the management of PBC and PSC relate to topics where evidence for current practice is weak and further research is needed.

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.

Tauroursodeoxycholic acid affects PPARγ and TLR4 in Steatotic liver transplantation

Numerous steatotic livers are discarded for transplantation because of their poor tolerance to ischemia-reperfusion (I/R). We examined whether tauroursodeoxycholic acid (TUDCA), a known inhibitor of endoplasmic reticulum (ER) stress, protects steatotic and nonsteatotic liver grafts preserved during 6 h in University of Wisconsin (UW) solution and transplanted. The protective mechanisms of TUDCA were also examined. Neither unfolded protein response (UPR) induction nor ER stress was evidenced in steatotic and nonsteatotic liver grafts after 6 h in UW preservation solution. TUDCA only protected steatotic livers grafts and did so through a mechanism independent of ER stress. It reduced proliferator-activated receptor-γ (PPARγ) and damage. When PPARγ was activated, TUDCA did not reduce damage. TUDCA, which inhibited PPARγ, and the PPARγ antagonist treatment up-regulated toll-like receptor 4 (TLR4), specifically the TIR domain-containing adaptor inducing IFNβ (TRIF) pathway. TLR4 agonist treatment reduced damage in steatotic liver grafts. When TLR4 action was inhibited, PPARγ antagonists did not protect steatotic liver grafts. In conclusion, TUDCA reduced PPARγ and this in turn up-regulated the TLR4 pathway, thus protecting steatotic liver grafts. TLR4 activating-based strategies could reduce the inherent risk of steatotic liver failure after transplantation.

Primary sclerosing cholangitis and bile acids

Primary sclerosing cholangitis (PSC) is a rare and complex chronic cholestatic liver disease, and its management is hindered by a very poor understanding of its pathogenesis. Endogenous bile acids are likely to play a role either directly or indirectly in the pathogenesis and/or progression of PSC ('toxic-bile'hypothesis). At present, no medical therapies have been proven to delay disease progression. Ursodeoxycholic acid (UDCA) is the agent that has received the most attention. Based on large randomized studies, it appears that UDCA at doses from 13 to 23 mg/kg/d has no proven benefit on survival, but is well tolerated and improves serum liver tests and surrogate markers of prognosis whereas, at higher doses (28-30 mg/kg/d), it is associated with a worsened outcome. However, except at very high doses and despite the controversies, many hepatologists still consider UDCA a reasonable treatment choice. Indeed, its use at dosages of 15-20 mg/kg/d has recently been approved for the treatment of PSC by the French National Health Authority. In addition, 24-nor-ursodeoxycholic acid, a side-chain-modified UDCA derivative, has shown promising results in animal models of PSC and is currently under investigation in humans.

Waking action of ursodeoxycholic acid (UDCA) involves histamine and GABAA receptor block

Since ancient times ursodeoxycholic acid (UDCA), a constituent of bile, is used against gallstone formation and cholestasis. A neuroprotective action of UDCA was demonstrated recently in models of Alzheimer's disease and retinal degeneration. The mechanisms of UDCA action in the nervous system are poorly understood. We show now that UDCA promotes wakefulness during the active period of the day, lacking this activity in histamine-deficient mice. In cultured hypothalamic neurons UDCA did not affect firing rate but synchronized the firing, an effect abolished by the GABA_AR antagonist gabazine. In histaminergic neurons recorded in slices UDCA reduced amplitude and duration of spontaneous and evoked IPSCs. In acutely isolated histaminergic neurons UDCA inhibited GABA-evoked currents and sIPSCs starting at 10 µM (IC₅₀ = 70 µM) and did not affect NMDA- and AMPA-receptor mediated currents at 100 µM. Recombinant GABA_A receptors composed of α1, β1–3 and γ2L subunits expressed in HEK293 cells displayed a sensitivity to UDCA similar to that of native GABA_A receptors. The mutation α1V256S, known to reduce the inhibitory action of pregnenolone sulphate, reduced the potency of UDCA. The mutation α1Q241L, which abolishes GABA_AR potentiation by several neurosteroids, had no effect on GABA_AR inhibition by UDCA. In conclusion, UDCA enhances alertness through disinhibition, at least partially of the histaminergic system via GABA_A receptors.

In PSC with colitis treated with UDCA, most colonic carcinomas develop in the first years after the start of treatment

BACKGROUND

Patients with PSC and IBD have a high incidence of colonic carcinomas (CRC), and the annual incidence of CRC increases with duration of disease. UDCA treatment has been suggested to reduce colonic dysplasias and carcinomas.

AIMS

The annual incidence of colorectal carcinomas after long-term UDCA treatment was studied.

METHODS

Patients included in a prospective study on the outcome after ursodeoxycholic acid (UDCA) treatment were evaluated.

RESULTS

A total of 120 of 171 PSC patients included had IBD (108 UC and 12 CD). All patients were treated with UDCA for a median time of 6.7 years. Seven patients with PSC and IBD developed a CRC yielding a prevalence of 5.8%. In years 0-3 (n = 120) after the start of UDCA, the annual incidence rate of CRC was 0.62/100 patient years; in years 3-6 (n = 93) it increased to 1.28 and decreased thereafter in years 6-9 (n = 67) to 1.17, then in years 9-12 (n = 42) to 0 and after >12 years (n = 24) it remained 0. In PSC with IBD, Kaplan-Meier estimate of CRC formation increased with time in the first years of treatment and reached a plateau after 9 years; after treatment for ≥ 9 years, no further CRC were observed.

CONCLUSION

After the start of UDCA, the annual incidence of CRC increased up to 6 years and subsequently decreased. In PSC with IBD treated with UDCA, most colonic carcinomas develop in the first years after the start of treatment.

Meta-analysis: ursodeoxycholic acid for primary sclerosing cholangitis

BACKGROUND

There is no satisfactory medical treatment for patients with primary sclerosing cholangitis. There are conflicting data regarding the clinical benefit of high doses of ursodeoxycholic acid (UDCA) in primary sclerosing cholangitis.

AIM

To evaluate using meta-analysis, if UDCA (standard or high-dose) is useful in primary sclerosing cholangitis.

METHODS

We searched MEDLINE using the textwords 'PSC', 'treatment', 'UDCA' and retrieved all abstracts from the major Gastroenterology and Liver meetings. We included randomised clinical trials comparing standard or high-dose of UDCA (>15 mg/kg body weight per day) vs. placebo or no intervention. End-points: mortality or liver transplantation, pruritus, fatigue, cholangiocarcinoma and histological progression.

RESULTS

We identified eight randomised clinical trials comprising 567 patients. Five used standard doses and three high doses of UDCA. There was no significant difference in mortality [OR, 0.6 (95% CI, 0.4-1.4)], in pruritus [OR, 1.5 (95% CI, 0.3-7.2)], in fatigue [OR, 0.0 (95% CI, 0.1-7.7)], in cholangiocarcinoma [OR, 1.7 (95% CI, 0.6-5.1)] and in histology stage progression [OR, 0.9 (95% CI, 0.34-2.44)]. No differences were found in the subgroup analyses.

CONCLUSION

Neither standard nor high-dose UDCA influence favourably the progression of primary sclerosing cholangitis.

A randomized controlled trial of high-dose ursodesoxycholic acid for nonalcoholic steatohepatitis

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is a prevalent liver disease associated with increased morbidity and mortality. Ursodeoxycholic acid (UDCA) may have antioxidant, anti-inflammatory, and antifibrotic properties and may reduce liver injury in NASH. To date, no studies have assessed the efficacy and safety of high-dose UDCA (HD-UDCA) in patients with NASH.

METHODS

We conducted a 12-month, randomized, double-blind, placebo-controlled multicenter trial to evaluate the efficacy and safety of HD-UDCA (28-35 mg/kg per day) in 126 patients with biopsy-proven NASH and elevated alanine aminotransferase (ALT) levels. The primary study end point was reduction in ALT levels from baseline in patients treated with HD-UDCA compared with placebo. Secondary study end points were the proportion of patients with ALT normalization, relative reduction in the scores of serum markers of fibrosis and hepatic inflammation, and safety and tolerability.

RESULTS

HD-UDCA significantly reduced mean ALT levels -28.3% from baseline after 12 months compared with -1.6% with placebo (p<0.001). At the end of the trial, ALT levels normalized (≤35 IU/L) in 24.5% of patients treated with HD-UDCA and in 4.8% of patients who received placebo (p=0.003). Both results were not accounted for by changes in weight during the trial. HD-UDCA significantly reduced the FibroTest® serum fibrosis marker (p<0.001) compared with placebo. HD-UDCA also significantly improved markers of glycemic control and insulin resistance. There were no safety issues in this population.

CONCLUSIONS

Treatment with HD-UDCA was safe, improved aminotransferase levels, serum fibrosis markers, and selected metabolic parameters. Studies with histologic end points are warranted.

[Primary sclerosing cholangitis: diagnosis, prognosis and treatment]

Primary sclerosing cholangitis is a chronic cholestatic disease characterized by inflammation with fibrosis and obliteration of the intra- and extrahepatic bile ducts. This disease is usually associated with ulcerative colitis. The process of chronic cholestasis eventually leads to biliary cirrhosis. The prevalence of primary sclerosing cholangitis is low in southern Europe but is especially high in Scandinavian countries. The etiopathogenesis is unknown but immune disorders, potential toxic agents or intestinal infections, ischemic injury to the bile ducts, and possibly alterations in hepatobiliary transporters are known to play a role. The disease manifests at the age of approximately 40 years, mainly in men with clinical and laboratory features of cholestasis but may also be asymptomatic. There are specific forms in which the small intrahepatic bile ducts are involved, mainly affecting children, as well as overlap syndromes with autoimmune hepatitis. A form characterized by an increase in IgG4 has been described, which is usually associated with autoimmune pancreatitis. The key diagnostic procedure is endoscopic retrograde cholangiography, although magnetic resonance cholangiography is the first diagnostic procedure that should be used since it is equally informative and non-invasive. Liver biopsy is not essential for diagnosis. Primary sclerosing cholangitis is a progressive disease with a probability of transplant-free survival of 18 years in asymptomatic forms and of 8.5 years in symptomatic forms. Cholangiocarcinoma can result from the disease and confers a poor prognosis. There is no specific treatment although ursodeoxycholic acid improves the biochemical alterations of cholestasis. Liver transplantation is the last therapeutic resort with good results in terms of survival although the disease can recur in the transplanted liver.

In PSC with dominant bile duct stenosis, IBD is associated with an increase of carcinomas and reduced survival

BACKGROUND & AIMS

In patients with primary sclerosing cholangitis (PSC) treated with ursodeoxycholic acid (UDCA), dominant stenoses are associated with reduced survival free of liver transplantation and the role of inflammatory bowel disease (IBD) in such patients is unclear. In the present study the influence of IBD on the outcome in patients with and without dominant stenosis has been evaluated.

METHODS

In a prospective study, 171 patients were followed for up to 20 years. All patients were treated with ursodeoxycholic acid; patients with dominant stenosis in addition were treated endoscopically.

RESULTS

A total of 97 out of 171 patients had or developed dominant bile duct stenoses and 96 out of 97 were treated endoscopically. In patients with dominant stenosis without IBD, no carcinoma was found whereas all six bile duct and two gallbladder carcinomas and 6/7 colo-rectal carcinomas were found in patients with dominant stenosis with IBD (p=0.012). In patients without dominant stenosis but with IBD, 1 out of 7 had colo-rectal carcinoma. In patients with dominant stenosis without IBD (n=30), actuarial survival free of liver transplantation at 18 years was 77.8% and in those with dominant stenosis and inflammatory bowel disease (n=67) it was 23.0% (p=0.045). In PSC patients without dominant stenosis and without IBD (n=21), actuarial survival free of liver transplantation at 18 years was 68.2% and in those with inflammatory bowel disease (n=53) it was 78.4% (n.s.).

CONCLUSIONS

In patients without dominant stenosis, IBD had no effect on the incidence of carcinomas and survival. Only patients with dominant stenosis with additional IBD had an increased carcinoma rate. This may contribute to the reduced survival free of liver transplantation in such patients.

A pilot trial of high-dose ursodeoxycholic acid in nonalcoholic steatohepatitis

PURPOSE

Standard dose (13-15 mg/kg) ursodeoxycholic acid (UCDA) is ineffective in the treatment of nonalcoholic steatohepatitis (NASH), however, its immunomodulatory and hepatoprotective effects are dose related. Therefore, we examined the impact of high-dose (28-32 mg/kg) UCDA on aminotransaminase levels in a pilot study of patients with NASH.

METHODS

Twelve patients with biopsy-proven NASH and elevated aminotransaminases were prescribed high-dose UCDA for 6 months. Liver function tests were monitored during and after treatment with the study endpoint defined as normalization of aminotransaminase levels.

RESULTS

Normalization of aspartate aminotransaminase (AST) levels was observed in two (17%) patients, however, no patient normalized their alanine aminotransaminase (ALT) levels. A trend towards a minor reduction in median (range) ALT values from baseline to end of treatment was noted [124 (66-229) vs. 101 (53-188) IU/l, p = 0.07], whereas AST levels remained unchanged [85 (40-132) vs. 98 (28-147) IU/l, p = 0.83]. One patient discontinued treatment prematurely due to diarrhea. No significant change in fasting glucose, triglyceride or HDL cholesterol was observed with treatment. No significant change in ALT or AST levels was observed in the 6-month period after cessation of treatment.

CONCLUSION

High-dose UCDA does not normalize aminotransaminase levels in patients with NASH. Other inexpensive well-tolerated agents for the treatment of NASH need to be investigated.

Bile acid changes after high-dose ursodeoxycholic acid treatment in primary sclerosing cholangitis: Relation to disease progression

High-dose (28-30 mg/kg/day) ursodeoxycholic acid (UDCA) treatment improves serum liver tests in patients with primary sclerosing cholangitis (PSC) but does not improve survival and is associated with increased rates of serious adverse events. The mechanism for the latter undesired effect remains unclear. High-dose UDCA could result in the production of hepatotoxic bile acids, such as lithocholic acid (LCA), because of limited small bowel absorption of UDCA and conversion of UDCA by bacteria in the colon. We determined the serum bile acid composition in 56 patients with PSC previously enrolled in a randomized, double-blind controlled trial of high-dose UDCA versus placebo. Samples for analysis were obtained at the baseline and at the end of treatment. The mean changes in the UDCA level (16.86 versus 0.05 micromol/L) and total bile acid level (17.21 versus -0.55 micromol/L) were significantly higher in the UDCA group (n = 29) versus the placebo group (n = 27) when pretreatment levels were compared (P < 0.0001). LCA was also markedly increased (0.22 versus 0.01 micromol/L) in the UDCA group compared to the placebo group (P = 0.001). No significant changes were detected for cholic acid, deoxycholic acid, or chenodeoxycholic acid. Patients (n = 9) in the UDCA group who reached clinical endpoints of disease progression (the development of cirrhosis, varices, liver transplantation, or death) tended to have greater increases in their posttreatment total bile acid levels (34.99 versus 9.21 micromol/L, P < 0.08) in comparison with those who did not.

CONCLUSION

High-dose UDCA treatment in PSC patients results in marked UDCA enrichment and significant expansion of the total serum bile acid pool, including LCA.

Bile salts and cholestasis

Bile salts have a crucial role in hepatobiliary and intestinal homeostasis and digestion. Primary bile salts are synthesized by the liver from cholesterol, and may be modified by the intestinal flora to form secondary and tertiary bile salts. Bile salts are efficiently reabsorbed from the intestinal lumen to undergo enterohepatic circulation. In addition to their function as a surfactant involved in the absorption of dietary lipids and fat-soluble vitamins bile salts are potent signaling molecules in both the liver and intestine. Under physiological conditions the bile salt pool is tightly regulated, but the adaptive capacity may fall short under cholestatic conditions. Elevated serum and tissue levels of potentially toxic hydrophobic bile salts during cholestasis may cause mitochondrial damage, apoptosis or necrosis in susceptible cell types. Therapeutic nontoxic bile salts may restore impaired hepatobiliary secretion in cholestatic disorders. The hydrophilic bile salt ursodeoxycholate is today regarded as the effective standard treatment of primary biliary cirrhosis and intrahepatic cholestasis of pregnancy, and is implicated for use in various other cholestatic conditions. Novel therapeutic bile salts that are currently under evaluation may also prove valuable in the treatment of these diseases.

Endoscopic dilation of dominant stenoses in primary sclerosing cholangitis: outcome after long-term treatment

BACKGROUND

Primary sclerosing cholangitis is characterized by progressive fibrotic inflammation and obliteration of intra- and/or extrahepatic bile ducts. Total or subtotal stenoses of major bile ducts are associated with reduced survival.

OBJECTIVE

To evaluate the outcome after long-term endoscopic treatment.

DESIGN

Prospective, single-center study.

SETTING

Tertiary care academic medical center.

PATIENTS

A total of 171 patients treated with ursodeoxycholic acid were followed for as long as 20 years. At entry, 20 patients had dominant stenoses, and during a median follow-up period of 7.1 years, dominant stenosis developed in another 77.

INTERVENTIONS

Ninety-six patients with dominant stenoses were treated by repeated balloon dilation; 5 patients with complete obstruction with bacterial cholangitis were stented.

MAIN OUTCOME MEASUREMENTS

Survival free of liver transplantation, number of procedures, complications.

RESULTS

In total, 500 balloon dilations were performed and 5 stents were placed. Complications were pancreatitis (2.2%), bacterial cholangitis (1.4%), and bile duct perforation (0.2%); there were no deaths. Repeated endoscopic interventions allowed the preservation of a functioning common bile duct and of at least 1 hepatic duct up to 2 cm above the bifurcation in all patients. Progression of intrahepatic bile duct and liver disease led to the need for liver transplantation in 22 of 96 patients. Five years after the first dilation of a dominant stenosis, the survival free of liver transplantation rate was 81%, and after 10 years, it was 52%.

LIMITATIONS

Single-center study, no control group, primary end-stage liver disease excluded.

CONCLUSION

Repeated endoscopic balloon dilations of dominant stenoses allow the preservation of a functioning common bile duct for many years.

Protective effects of glycoursodeoxycholic acid in Barrett's esophagus cells

Barrett's esophagus (BE) is a premalignant condition associated with the development of esophageal adenocarcinoma (EAC). Previous studies have implicated hydrophobic bile acids and gastric acid in BE and EAC pathogenesis. In this study, we tested the hypothesis that DNA damage, cytotoxicity and oxidative stress induced by bile acids and gastric acid can be attenuated by the cytoprotective, hydrophilic bile acid glycoursodeoxycholic acid (GUDCA). Non-dysplastic BE cells were exposed for 10 min to pH 4 and/or bile acid cocktail or to pH 4 and a modified cocktail consisting of a mixture of bile acids and GUDCA. DNA damage was evaluated by the comet assay; cell viability and proliferation were measured by trypan blue staining and the MTS assay; reactive oxygen species (ROS) were measured using hydroethidium staining; oxidative DNA/RNA damage was detected by immunostaining with antibody against 8-OH-dG; thiol levels were measured by 5-chloromethylfluorescein diacetate (CMFDA) staining; and the expression of antioxidant proteins was evaluated by western blotting. DNA damage and oxidative stress were significantly increased, while thiol levels were decreased in BE cells treated with pH 4 and bile acid cocktail compared with cells treated with pH 4 alone or untreated cells. Bile acids and low pH also significantly decreased cell proliferation. Expression of the antioxidant enzymes, MnSOD and CuZnSOD, was elevated in the cells treated with bile acids and low pH. When GUDCA was included in the medium, all these effects of pH 4 and bile acids were markedly reduced. In conclusion, treatment of BE cells with acidified medium and a bile acid cocktail at physiologically relevant concentrations induces DNA damage, cytotoxicity, and ROS. The cytoprotective bile acid, GUDCA, inhibits these deleterious effects by inhibiting oxidative stress.

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.

More right-sided IBD-associated colorectal cancer in patients with primary sclerosing cholangitis

BACKGROUND

Patients with inflammatory bowel disease (IBD) and concurrent primary sclerosing cholangitis (PSC) have a higher risk of developing colorectal cancer (CRC) than IBD patients without PSC. The aim of this study was to investigate potential clinical differences between patients with CRC in IBD and those with CRC in IBD and PSC, as this may lead to improved knowledge of underlying pathophysiological mechanisms of CRC development.

METHODS

The retrospective study from 1980-2006 involved 7 Dutch university medical centers. Clinical data were retrieved from cases identified using the national pathology database (PALGA).

RESULTS

In total, 27 IBD-CRC patients with PSC (70% male) and 127 IBD-CRC patients without PSC (59% male) were included. CRC-related mortality was not different between groups (30% versus 19%, P = 0.32); however, survival for cases with PSC after diagnosing CRC was lower (5-year survival: 40% versus 75% P = 0.001). Right-sided tumors were more prevalent in the PSC group (67% versus 36%, P = 0.006); adjusted for age, sex, and extent of IBD, this difference remained significant (odds ratio: 4.8, 95% confidence interval [CI] 2.0-11.8). In addition, tumors in individuals with PSC were significantly more advanced.

CONCLUSIONS

The right colon is the predilection site for development of colonic malignancies in patients with PSC and IBD. When such patients are diagnosed with cancer they tend to have more advanced tumors than patients with IBD without concurrent PSC, and the overall prognosis is worse. Furthermore, the higher frequency of right-sided tumors in patients with PSC suggests a different pathogenesis between patients with PSC and IBD and those with IBD alone.

Ursodeoxycholic acid in primary sclerosing cholangitis: meta-analysis of randomized controlled trials

AIMS

The effect of ursodeoxycholic acid (UDCA) treatment on survival and liver histological progression of primary sclerosing cholangitis (PSC) remains uncertain. The aim of the present study was to evaluate the effect and safety of UDCA in PSC.

METHODS

Electronic databases including Medline, Embase, Cochrane controlled trials register, Web of Science and PubMed (updated to January 2009) and manual bibliographical searches were carried out. A meta-analysis of all randomized controlled trials (RCT) comparing UDCA with placebo or no treatment was carried out.

RESULTS

Eight RCT including 465 patients were assessed. UDCA could significantly improve liver biochemistry, but had no effect on pruritus and fatigue. Meta-analysis of the included RCT showed UDCA had no significant effect on the incidence of death, liver transplantation, and death and/or liver transplantation. However, a significant difference for the incidence of histological improvement was found between the two groups (odds ratio [OR], 9.19; 95% CI: 0.98, 86.15; P = 0.05). Meta-analysis also indicated a reduction trend of histological deterioration and an improvement trend of cholangiographic changes. These trends were constant in the sensitivity analyses.

CONCLUSION

The meta-analysis found that UDCA can improve liver biochemistry and there is a trend towards improvement in liver histology and cholangiography, but has no effect on survival free of transplantation.

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC.

Influence of dominant bile duct stenoses and biliary infections on outcome in primary sclerosing cholangitis

BACKGROUND/AIMS

In primary sclerosing cholangitis (PSC) dominant stenoses are frequently associated with bacterial, and in part, also fungal infections of the bile ducts. In the present study, the influence of dominant stenoses and of biliary infections on the long-term outcome was studied.

METHODS

In a prospective study, 171 patients were followed up for 20 years. All patients were treated with ursodeoxycholic acid. Dominant stenoses were treated endoscopically and during endoscopic procedures, bile was obtained for microbiologic analysis.

RESULTS

Of the 171 patients, 97 had or developed major bile duct stenoses and 96/97 were treated endoscopically. In the 55/97 patients with dominant stenosis, bile samples were obtained and of these, 41/55 had bacteria, five had also Candida and 2/55 had only Candida in their bile. Survival free of liver transplantation in patients without dominant stenosis at 18 years was 73.1% and of patients with dominant stenosis was 25.0% (p=0.011). Bacteria in bile had no effect on survival whereas Candida in bile was associated with reduced survival (p=0.025).

CONCLUSIONS

In patients with dominant stenosis, survival free of liver transplantation is reduced. Bacteria in bile do not worsen the outcome if dominant stenoses are opened endoscopically and infection is adequately treated with antibiotics. Candida in bile is associated with a poor prognosis and these patients need liver transplantation relatively soon.

Absence of glycochenodeoxycholic acid (GCDCA) in human bile is an indication of cholestasis: a 1H MRS study

The utility of (1)H MR spectroscopy in detecting chronic cholestasis has been investigated. The amide proton region of the (1)H MR spectrum of human bile plays a major role in differentiating cholestatic (Ch) patterns from the normal ones. Bile obtained from normal bile ducts contains both taurine and glycine conjugates of bile acids--cholic acid (CA), chenodeoxycholic acid (CDCA), and deoxycholic acid (DCA). Absence of a glycine-conjugated bile acid glycochenodeoxycholic acid (GCDCA) has been observed in bile samples obtained from primary sclerosing cholangitis (PSC) patients. A total of 32 patients with various hepatobiliary diseases were included in the study. Twenty-one patients had PSC and 11 had normal cholangiograms. One PSC patient was excluded from the study because of a bad spectrum. Seventeen out of the 20 PSC patients showed an absence of GCDCA in their (1)H MR spectrum of bile. Six of the 11 reference patients with normal cholangiogram also showed spectra similar to those of PSC, indicating the possibility of cholestasis. DQF-COSY and TOCSY experiments performed on bile samples from PSC patients also revealed absence of phosphatidylcholine (PC) in some of the bile samples, suggesting possible damage to the cholangiocytes by the toxic bile. These observations suggest that analysis of human bile by (1)H MRS could be of value in the diagnosis of chronic Ch liver disorders.

Chronic administration of ursodeoxycholic acid decreases portal pressure in rats with biliary cirrhosis

Liver cirrhosis is characterized by increased IHR (intrahepatic resistance) and lipid peroxidation, and decreased antioxidative defence. The present study investigates the effects of administration for 1 month of the antioxidant UDCA (ursodeoxycholic acid) in BDL (bile-duct-ligated) cirrhotic rats. Splanchnic haemodynamics, IHR, hepatic levels of TBARS (thiobarbituric acid-reacting substances), GSH (glutathione), SOD (superoxide dismutase) activity, nitrite, PIIINP (N-terminal propeptide of type III procollagen) and collagen deposition, histological examination of liver, mRNA expression of PIIIP-alpha1 (type III procollagen) and TGF-beta1 (transforming growth factor-beta1), protein expression of TXS (thromboxane synthase) and iNOS (inducible NO synthase), and TXA2 (thromboxane A2) production in liver perfusates were measured. The results showed that portal pressure and IHR, hepatic levels of PIIINP, hepatic collagen deposition, mRNA expression of PIIIP-alpha1 and TGF-beta1, protein expression of iNOS and TXS, and production of TXA2 in liver perfusates were significantly decreased in UDCA-treated BDL rats. The increased levels of hepatic GSH and SOD activity and decreased levels of TBARS and nitrite were also observed in UDCA-treated BDL rats. In UDCA-treated BDL rats, the reduction in portal pressure resulted from a decrease in IHR, which mostly acted through the suppression of hepatic TXA2 production and lipid peroxidation, and an increase in antioxidative defence, leading to the prevention of hepatic fibrosis.

Current status of therapy in autoimmune liver disease

Therapeutic strategies for autoimmune liver diseases are increasingly established. Although proportionately uncommon, specialist centers have with time refined the best approaches for each disease, based on an improved understanding of the spectrum of presentation. The major treatment aims are to prevent end-stage liver disease and its associated complications. As a result of drugs such as ursodeoxycholic acid, predniso(lo)ne and azathioprine, both primary biliary cirrhosis and autoimmune hepatitis are now less commonly indications for liver transplantation. Unfortunately, the same inroads in treatment efficacy have as yet not been made for primary sclerosing cholangitis, although the recognition that a subset of patients may have a treatable secondary sclerosing cholangitis (IgG4 related) is helping a proportion. With better biological understanding, more specific interventions are expected that will benefit all those with autoimmune liver diseases.

TUDCA prevents cholestasis and canalicular damage induced by ischemia-reperfusion injury in the rat, modulating PKCalpha-ezrin pathway

Cholestasis, induced by liver ischemia-reperfusion injury (IRI), is characterized by dilatation of bile canaliculi and loss of microvilli. Tauroursodeoxycholic acid (TUDCA) is an anti-cholestatic agent, modulating protein kinase C (PKC) alpha pathway. PKC reduces ischemic damage in several organs, its isoform alpha modulates ezrin, a key protein in the maintenance of cell lamellipoidal extensions. We evaluated the effects of TUDCA on cholestasis, canalicular changes and PKCalpha-ezrin expression in a rat model of liver IRI. Livers flushed and stored with Belzer solution or Belzer + 10 mm TUDCA (4 degrees C for 6 h) were reperfused (37 degrees C with O(2)) with Krebs-Ringer bicarbonate + 2.5 micromol/min of Taurocholate or TUDCA. Bile was harvested for bile flow assessment. Liver tissue was employed for Electron Microscopy (EM) and for PKCalpha and ezrin immunoblot and immunofluorescence. The same experiments were conducted with the PKCalpha inhibitor Go-6976. TUDCA-treated livers showed increased bile flow (0.25+/-0.17 vs. 0.042+/-0.02 microl/min/g liver, P<0.05) and better preservation of microvilli and bile canalicular area at EM. These effects were associated with increased PKCalpha and ezrin expression (P=0.03 and P=0.04 vs. control respectively), as also confirmed by immunofluorescence data. PKCalpha inhibition abolished these TUDCA effects. TUDCA administration during IRI reduces cholestasis and canalicular damage in the liver modulating PKCalpha-ezrin pathway.

The challenges in primary sclerosing cholangitis--aetiopathogenesis, autoimmunity, management and malignancy

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease, characterized by progressive inflammation and fibrosis of the bile ducts, resulting in biliary cirrhosis and is associated with a high risk of cholangiocarcinoma. The majority of patients are young, male and have coexisting inflammatory bowel disease. PSC is found with a prevalence of 10/100,000 in Northern European populations. The pathophysiology of PSC is a complex multistep process including immunological mechanisms, immunogenetic susceptibility and disorders of the biliary epithelia. The diagnosis is primarily based on endoscopic cholangiography although magnetic resonance imaging is increasingly used; biochemistry and immunoserology as well as histology play only a minor role. Due to the high risk of developing cholangiocarcinoma and also other tumours of the GI tract, surveillance strategies are essential, however they have yet to be established and evaluated. Biochemical parameters, clinical risk factors, endoscopic procedures and imaging techniques contribute to the early identification of patients at risk. Since medical therapy of PSC with ursodeoxycholic acid does not improve survival, to date, liver transplantation is the only option with a cure potential; if transplantation is accurately timed, transplanted PSC patients have an excellent rate of survival. However if cholangiocarcinoma is detected, a curative treatment is not possible in the majority of cases. The present review critically summarizes the current knowledge on the aetiopathogenesis of PSC and gives an overview of the diagnostic approaches, surveillance strategies and therapeutic options. Primary sclerosing cholangitis is a disease of unknown aetiology and without any further curative treatment options apart from liver transplantation. Therefore it may be regarded as the greatest challenge in hepatology today.

Current diagnosis and management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an important liver disease with major morbidity and mortality. The diagnosis of PSC is confirmed by magnetic resonance cholangiopancreaticography, and endoscopic retrograde cholangiopancreaticography is performed in patients needing therapeutic endoscopy. As a result of the unknown cause of the disease, current medical therapies are unsatisfactory. Nevertheless, high-dose ursodeoxycholic acid should be recommended for treatment of PSC patients because there is a trend toward increased survival. Dominant bile duct stenoses should be treated endoscopically. However, liver transplantation continues to be the only therapeutic option for patients with advanced disease. Estimation of prognosis and timing of liver transplantation should be determined individually for each PSC patient on the basis of all results. The diagnosis and treatment of cholangiocarcinoma (CC) still remain a challenge in PSC patients. Early diagnosis of CC certainly is a prerequisite for successful treatment with surgical resection or innovative strategies such as neoadjuvant radiochemotherapy with subsequent orthotopic liver transplantation. Therefore, endoscopic techniques such as cholangioscopy and/or intraductal ultrasound may be useful diagnostic tools in patients with stenoses suspicious for malignancy.

The effect of oral administration of ursodeoxycholic acid and high-dose proton pump inhibitors on the histology of Barrett's esophagus

Bile acids may play a role in the pathogenesis of Barrett's esophagus (BE). Bile composition can be influenced by oral administration of ursodeoxycholic acid (UDCA). We prospectively investigated the effect of proton pump inhibitors (PPI) supplemented with UDCA in vivo in patients with BE. Patients with no or low-grade dysplasia who were clinically asymptomatic on PPI were eligible for the study. In order to exclude the effects of acid reflux, all patients were initially treated with 40 mg esomeprazole (ESO) twice daily for 6 months and continued on this dose till the end of the study (t = 12 months). During a period of 6 months (t = 6 month - t = 12 month) patients were treated with oral UDCA (600 mg twice daily). Patients underwent endoscopy at t = 0 months, t = 6 months and t = 12 months with multiple biopsies of the distal and proximal BE segment, normal squamous and gastric cardia. In addition, pH was measured at t = 0 months and t = 6 months using a BRAVO wireless pH capsule. Bile was sampled at the beginning of the UDCA treatment and 6 months later (t = 6 month and t = 12 month). All biopsies were reviewed for the extent of metaplasia, dysplasia, and acute and chronic inflammation. In addition, proliferation (Ki67), differentiation (villin, cytokeratins 7 and 20) and inflammation (COX-2) were investigated by immunohistochemistry (IHC). Nine patients (mean age 60 years, median BE length 7 cm) were included, of whom six had no dysplasia and three had low-grade dysplasia. pH measurements revealed a normal acid exposure in most patients at t = 0 and t = 6 months. In addition, bile composition analysis demonstrated the efficacy of UDCA. Combining the results of both phases of the study, no significant changes were seen in any of the histological or IHC parameters. Differentiation and proliferation parameters showed no significant changes. In this study, in BE patients who were clinically asymptomatic on PPI, increasing the PPI dose to the maximum for 6 months followed by the addition of UDCA for 6 months did not result in significant histological or IHC changes in their BE.

High dose ursodeoxycholic acid for the treatment of primary sclerosing cholangitis is safe and effective

BACKGROUND/AIMS

Ursodeoxycholic acid (UDCA) has been shown to improve serum liver tests in primary sclerosing cholangitis (PSC), but controlled trials have shown inconsistent effects on liver histology, and did not reveal a survival benefit. This pilot, randomised dose-ranging trial attempted to determine whether further enrichment of the bile acid pool with UDCA would lead to an improvement in outcome for PSC patients.

METHODS

Thirty-one patients with PSC were randomised to treatment with either 10 mg/kg (low dose), 20 mg/kg (standard dose) or 30 mg/kg (high dose) daily of UDCA for 2 years. Patients were assessed every 12 weeks and underwent liver biopsy at the beginning and end of the trial.

RESULTS

Serum liver tests improved in all groups taking UDCA. Survival probability at 1-4 years as evaluated by the Mayo risk score tended to improve for all patients and significantly improved for the high dose group (p<0.02). Only 3 (10%) of all patients had a Ludwig score showing histological deterioration over the trial period.

CONCLUSIONS

High dose UDCA is well-tolerated and is associated with an improvement in survival probability. A trend towards stability/improvement in histological stage was also observed. This treatment appears to be effective for PSC and deserves further evaluation.

Treatment of primary sclerosing cholangitis

Aims of treatment for primary sclerosing cholangitis are as follows: prevention of progression of hepatobiliary disease, reduction of symptoms and consequences of cholestasis (pruritus, osteoporosis), and prevention of complications (colorectal cancer, hepatobiliary cancer). Ursodeoxycholic acid (UDCA) improves biliary secretion and laboratory parameters of cholestasis, but its effects on liver histology and survival are not clear. It reduces the incidence of dysplasias and carcinomas of the colon in patients with colitis and possibly has a beneficial effect on the incidence of bile duct carcinomas. At present, UDCA represents the most promising therapeutic option. Immunosuppressive treatment has not been proven to be effective; it appears to be indicated in the overlap syndrome with autoimmune hepatitis but may be harmful in bacterial cholangitis. Bacterial cholangitis is common in patients with dominant stenoses and requires antibiotic treatment. Endoscopic treatment of dominant stenoses improves cholestasis and prolongs survival in comparison to predicted survival. Pruritus represents a problem in some patients, and cholestyramine represents the first-line treatment. If ineffective, opioid antagonists, rifampin, or ondansetron may be tried. For treatment of osteoporosis and osteopenia, calcium and vitamin D supplementation are recommended, and in selected cases, bisphosphonates may be indicated. In patients with severe cholestasis and coagulation defects, parenteral supplementation of vitamin K may be indicated. During treatment, all patients should be regularly screened for colonic and bile duct carcinomas. Patients with cirrhosis of the liver and its complications are treated accordingly, and in end-stage disease, liver transplantation is indicated.

Medical treatment of cholestatic liver disease

In most cholestatic liver diseases the cause of the disease is not known and therapy can only be directed toward suppression of the pathogenetic processes and amelioration of the consequences of cholestasis. The recognition of adaptive-compensatory responses to cholestasis has become of major importance. They tend to minimize retention of bile acids and other potentially toxic solutes in the hepatocyte by limiting hepatocellular uptake, reducing bile acid synthesis, stimulating detoxification, and up-regulating alternative pathways for excretion. Some of the drugs used for the treatment of cholestatic liver diseases in an empiric way turned out to be modulators of nuclear receptors, which regulate these adaptive-compensatory responses. New drugs are being designed and tested along these lines and may be regarded as treatment opportunities of the future.

The incidence of cholangiocarcinoma in primary sclerosing cholangitis after long-time treatment with ursodeoxycholic acid

BACKGROUND/AIMS

Cholangiocarcinoma represents a serious complication of primary sclerosing cholangitis. Ursodeoxycholic acid may possibly influence the incidence of cholangiocarcinoma in man. The aim of this study was to evaluate the incidence rate of cholangiocarcinoma in a large group of primary sclerosing cholangitis patients after long-time treatment with ursodeoxycholic acid.

PATIENTS AND METHODS

From May 1987 up to May 2005 a total of 150 patients with primary sclerosing cholangitis but without evidence of cholangiocarcinoma at entry were included in the study. All patients were treated with ursodeoxycholic acid and controls were performed in at least yearly intervals.

RESULTS

The median treatment time of the 150 patients was 6.4 years. Altogether five patients developed a cholangiocarcinoma during treatment yielding a rate of 3.3%. The patients developed 0.58 cholangiocarcinoma per 100 patient-years in years 0-2.5, 0.59 cholangiocarcinoma in years 2.5-8.5, and no cholangiocarcinoma thereafter up to 18 years after entry into the study. The Kaplan-Meier estimate of cholangiocarcinoma incidence during ursodeoxycholic acid treatment reached a plateau after 8.3 years.

SUMMARY AND CONCLUSION

The annual incidence rate of cholangiocarcinoma in primary sclerosing cholangitis treated with ursodeoxycholic acid is lower than expected and decreases with time of treatment.

Liver involvement in cystic fibrosis

The hepatobiliary manifestations of cystic fibrosis (CF) encompass a broad clinical spectrum, from mild steatosis, associated with poor nutrition, to multilobular cirrhosis and the complications of portal hypertension. The factor(s) responsible for the development and progression of liver disease in a subset of patients with CF are unknown. Liver disease can be silent and progressive, manifesting only with complications associated with cirrhosis and portal hypertension. Clinical evaluation for detecting and monitoring the progression of liver disease includes the following: physical examination of the liver, biochemical tests of liver function and injury, and radiological imaging with abdominal ultrasonography. Careful monitoring should take place in all patients with CF, as currently, there are no sensitive and/or specific historical or biochemical markers to predict who is at risk for the development of liver disease. Current treatment options for CF-associated liver disease are very limited. The bile acid ursodeoxycholic acid may improve biochemical parameters of liver disease, but its long-term efficacy in preventing the progression of liver disease in CF is unproven. Treatment therefore rests on optimizing nutritional status; correcting fat-soluble vitamin, essential fatty acid, and other mineral deficiencies; and treating complications of end-stage liver disease, such as pruritus, ascites, and portal hypertension.

Drug insight: Mechanisms and sites of action of ursodeoxycholic acid in cholestasis

Ursodeoxycholic acid (UDCA) exerts anticholestatic effects in various cholestatic disorders. Several potential mechanisms and sites of action of UDCA have been unraveled in clinical and experimental studies, which could explain its beneficial effects. The relative contribution of these mechanisms to the anticholestatic action of UDCA depends on the type and stage of the cholestatic injury. In early-stage primary biliary cirrhosis and primary sclerosing cholangitis, protection of injured cholangiocytes against the toxic effects of bile acids might prevail. Stimulation of impaired hepatocellular secretion by mainly post-transcriptional mechanisms, including stimulation of synthesis, targeting and apical membrane insertion of key transporters, seems to be relevant in more advanced cholestasis. In intrahepatic cholestasis of pregnancy, stimulation of impaired hepatocellular secretion could be crucial for rapid relief of pruritus and improvement of serum liver tests, as it is in some forms of drug-induced cholestasis. In cystic fibrosis, stimulation of cholangiocellular calcium-dependent secretion of chloride and bicarbonate ions could have a major impact. Inhibition of bile-acid-induced hepatocyte apoptosis can have a role in all states of cholestasis that are characterized by hepatocellular bile-acid retention. Different mechanisms of action could, therefore, contribute to the beneficial effect of UDCA under various cholestatic conditions.

Early treatment with ursodeoxycholic acid for cholestasis in children on parenteral nutrition because of primary intestinal failure

BACKGROUND

There is conflicting evidence as to whether ursodeoxycholic acid (UDCA) reduces the incidence of parenteral nutrition-associated cholestasis.

AIM

To investigate the efficacy of UDCA on parenteral nutrition-associated cholestasis in children with intestinal failure due to short bowel syndrome or to other causes.

METHODS

Children with cholestasis received 30 mg/kg/day UDCA. Improvement or normalization of parenteral nutrition-associated cholestasis was evaluated at 6 months of therapy and at the last follow-up. In a subgroup of children, serum UDCA levels were measured while receiving UDCA and after 4 weeks withdrawal.

RESULTS

Twelve children were treated with UDCA. Full remission or partial improvement of parenteral nutrition-associated cholestasis occurred in 11 of 12 children. In three of four children, withdrawal of UDCA was associated with a rebound rise of cholestasis. Only one of 12 treated children showed no improvement and in this patient, in contrast to four other patients, plasma levels of UDCA did not increase during treatment.

CONCLUSIONS

Ursodeoxycholic acid was effective in controlling parenteral nutrition-associated cholestasis. The efficacy of UDCA also in children with short bowel is related to intestinal absorption.

Sclerosing cholangitis

PURPOSE OF REVIEW

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by strictures of the biliary tree complicated by cirrhosis and cholangiocarcinoma. It is immune mediated although the precise etiology remains unknown.

RECENT FINDINGS

Research into etiopathogenesis, epidemiology, the relationship with inflammatory bowel disease, diagnosis of cholangiocarcinoma, medical therapy, and the outcome of liver transplantation are discussed.

SUMMARY

It is likely that a number of patients previously diagnosed with primary sclerosing cholangitis have autoimmune pancreatitis in association with primary sclerosing cholangitis, a syndrome with distinct clinicopathological features including steroid responsiveness. Primary sclerosing cholangitis-inflammatory bowel disease probably represents a distinct inflammatory bowel disease phenotype, which has implications for colonoscopic surveillance of these patients. CA19-9 plays no surveillance role for the early detection of cholangiocarcinoma. The best-studied drug in primary sclerosing cholangitis is ursodeoxycholic acid, which, despite a range of potentially valuable actions on the cholestatic liver, has not yet been proved to make a substantial impression on the course of the disease. Orthotopic liver transplantation remains the only established long-term treatment for primary sclerosing cholangitis.

Extraintestinal manifestations in inflammatory bowel disease

Inflammatory bowel diseases (IBD) can be really considered to be systemic diseases since they are often associated with extraintestinal manifestations, complications, and other autoimmune disorders. Indeed, physicians who care for patients with ulcerative colitis and Crohn's disease, the two major forms of IBD, face a new clinical challenge every day, worsened by the very frequent rate of extraintestinal complications. The goal of this review is to provide an overview and an update on the extraintestinal complications occurring in IBD. Indeed, this paper highlights how virtually almost every organ system can be involved, principally eyes, skin, joints, kidneys, liver and biliary tracts, and vasculature (or vascular system) are the most common sites of systemic IBD and their involvement is dependent on different mechanisms.

Effect of colitis and ileoanal pouch on biliary enrichment of ursodeoxycholic acid in primary sclerosing cholangitis

In primary sclerosing cholangitis (PSC), biliary enrichment of ursodeoxycholic acid (UDCA) may represent the decisive factor for its presumable beneficial effect. Up to now it is not clear how colitis and colectomy with ileo-anal pouch affect the biliary enrichment of UDCA and the biliary bile acid composition. We determined the biliary bile acid composition in 63 patients with PSC including 7 patients with ileo-anal pouch, 31 patients with colitis, and 25 patients without colitis. No differences existed between patients with and those without colitis. In patients with colectomy and pouch at a UDCA dose of 17.7 +/- 1.6 mg/kg (n = 7), biliary UDCA represented 46.4 +/- 6.7% (mean +/- SD) of total bile acids. An increase in the dose in six pouch patients from 12.5 +/- 0.9 to 22.3 +/- 1.6 mg/kg led to a slight increase in biliary enrichment of UDCA, from 39.8 +/- 8.1 to 49.4 +/- 10.7%. In five of seven patients with ileo-anal pouch, biliary UDCA enrichment was within the normal range, and in two of seven it was permanently or intermittently abnormally low. During UDCA treatment, in pouch patients the biliary content of deoxycholic acid and lithocholic acid was reduced, whereas all other bile acids were unchanged. In a minority of patients with ileo-anal pouch, biliary enrichment of UDCA may be markedly reduced, whereas patients with colitis have a biliary UDCA enrichment not different from that of patient without colitis.