Serum bile acids in primary biliary cirrhosis: effect of ursodeoxycholic acid therapy

Synthesis of TUDCA from chicken bile: immobilized dual-enzymatic system for producing artificial bear bile substitute

Bear bile, a valuable animal-derived medicinal substance primarily composed of tauroursodeoxycholic acid (TUDCA), is widely distributed in the medicinal market across various countries due to its significant therapeutic potential. Given the extreme cruelty involved in bear bile extraction, researchers are focusing on developing synthetic bear bile powder as a more humane alternative. This review presents an industrially practical and environmentally friendly process for producing an artificial substitute for bear bile powder using inexpensive and readily available chicken bile powder through an immobilized 7α-,7β-HSDH dual-enzymatic syste. Current technology has facilitated the industrial production of TUDCA from Tauodeoxycholic acid (TCDCA) using chicken bile powder. The review begins by examining the chemical composition, structure, and properties of bear bile, followed by an outline of the pharmacological mechanisms and manufacturing methods of TUDCA, covering chemical synthesis and biotransformation methods, and a discussion on their respective advantages and disadvantages. Finally, the process of converting chicken bile powder into bear bile powder using an immobilized 7α-Hydroxysteroid Dehydrogenases(7α-HSDH) with 7β- Hydroxysteroid Dehydrogenases (7β-HSDH) dual-enzyme system is thoroughly explained. The main objective of this review is to propose a comprehensive strategy for the complete synthesis of artificial bear bile from chicken bile within a controlled laboratory setting.

Ursodeoxycholic Acid's Effectiveness in the Management of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

Aim

This meta-analysis's objective was to assess the effectiveness of ursodeoxycholic acid (UDCA) in the management of nonalcoholic fatty liver disease (NAFLD).

Methods

Electronic databases like PubMed, Embase, Scopus, and Cochrane Library were thoroughly looked for randomized controlled trials determining ursodeoxycholic acid's (UDCAs) effectiveness on the serum liver function tests in NAFLD patients. After screening, seven randomized controlled trials were incorporated overall. Utilizing a fixed effects model, quantitative data synthesis was performed in R version 4.3.1.

Results

The meta-analysis showed significant reductions in alanine transaminase (ALT) (p ≤ 0.0001), aspartate transaminase (p = 0.0009), and gamma-glutamyl transferase (GGT) (p ≤ 0.0001) after UDCA therapy. However, significant reductions in bilirubin (p = 0.6989) and alkaline phosphatase (ALP) (p = 0.1172) levels were not noted. Sensitivity analysis by removing the studies with some concerns of bias was successful in demonstrating a remarkable reduction in heterogeneity for aspartate transaminase and ALP, which was also observed while performing the subgroup analyses via dosage.

Conclusion

Ursodeoxycholic acid was beneficial in patients diagnosed with NAFLD as it significantly reduced aspartate transaminase, ALT and GGT levels. However, more randomized controlled trials are required to be conducted in the future to increase the certainty of the evident findings.

Clinical significance

This meta-analysis strengthens the evidence about the reductions in AST, ALT, and GGT levels observed with ursodeoxycholic acid therapy in NAFLD patients by pooling the data together from the latest RCTs thus proving its hepatoprotective effects which can be beneficial in preventing the associated complications.

How to cite this article

Patel VS, Mahmood SF, Bhatt KH, et al. Ursodeoxycholic Acid's Effectiveness in the Management of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis. Euroasian J Hepato-Gastroenterol 2024;14(1):92-98.

Altered gut microbiome, bile acid composition and metabolome in sarcopenia in liver cirrhosis

BACKGROUND

Sarcopenia in liver cirrhosis is associated with low quality of life and high mortality risk. The pathogenesis has yet to be fully understood. We hypothesized that gut microbiome, bile acid (BA) composition and metabolites differ between cirrhotic patients with and without sarcopenia and contribute to pathogenesis.

METHODS

Cirrhotic patients with (n = 78) and without (n = 38) sarcopenia and non-cirrhotic controls with (n = 39) and without (n = 20) sarcopenia were included in this study. Faecal microbiome composition was studied by 16S rDNA sequencing, serum and faecal BA composition by ultra-high-performance liquid chromatography-tandem mass spectrometry, and metabolite composition in serum, faeces and urine by nuclear magnetic resonance.

RESULTS

Bacteroides fragilis, Blautia marseille, Sutterella spp. and Veillonella parvula were associated with cirrhotic patients with sarcopenia, whereas Bacteroides ovatus was more abundant in cirrhotic patients without sarcopenia. We observed significantly elevated secondary BAs, deoxycholic acid (DCA; P = 0.01) and lithocholic acid (LCA; P = 0.02), and the ratios of deoxycholic acid to cholic acid (DCA:CA; P = 0.04), lithocholic acid to chenodeoxycholic acid (LCA:CDCA; P = 0.03) and 12 alpha-hydroxylated to non-12 alpha-hydroxylated BAs (12-α-OH:non-12-α-OH BAs; P = 0.04) in serum of cirrhotic patients with sarcopenia compared with cirrhotic patients without sarcopenia, indicating an enhanced transformation of primary to secondary BAs by the gut microbiome. CA (P = 0.02) and the ratios of CA:CDCA (P = 0.03) and total ursodeoxycholic acid to total secondary BAs (T-UDCA:total-sec-BAs, P = 0.03) were significantly reduced in the stool of cirrhotic patients with sarcopenia compared with cirrhotic patients without sarcopenia. Also, valine and acetate were significantly reduced in the serum of cirrhotic patients with sarcopenia compared with cirrhotic patients without sarcopenia (P = 0.01 and P = 0.03, respectively). Multivariate logistic regression further confirmed the association of B. ovatus (P = 0.01, odds ratio [OR]: 12.8, 95% confidence interval [CI]: 168.1; 2.2), the ratios of 12-α-OH:non-12-α-OH BAs (P = 0.03, OR: 2.54, 95% CI: 0.99; 6.55) and T-UDCA:total-sec-BAs (P = 0.04, OR: 0.25, 95% CI: 0.06; 0.98) in serum and stool CA:CDCA (P = 0.04, OR: 0.79, 95% CI: 0.62; 0.99), and serum valine (P = 0.04, OR: 1.00, 95% CI: 1.02; 1.00) with sarcopenia in cirrhosis after correcting for the severity of liver disease and sex.

CONCLUSIONS

Our study suggests a potential functional gut microbiome-host interaction linking sarcopenia with the altered gut microbiomes, BA profiles and amino acids pointing towards a potential mechanistic interplay in understanding sarcopenia pathogenesis.

Rapid identification of bear bile powder from other bile sources using chip-based nano-electrospray ionization tandem mass spectrometry

RATIONALE

Bear bile powder (BBP) is a widely used traditional Chinese medicine (TCM), and bile acids (BAs) are the main active components in BBP. Due to the scarcity of BBP resources, adulterations often occur in the market. Conventional methods to distinguish them are usually complicated and time-consuming. To enhance effectiveness and accuracy, a rapid and rough analytical method is desperately needed.

METHODS

In this study, a rapid strategy using chip-based nano-electrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) was established to distinguish BBP from other sources of bile powder (BP). In addition, the results were further verified by ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry (UPLC/MS).

RESULTS

The precision of the chip-based nano-ESI-MS/MS method was validated to be acceptable with relative standard deviation (RSD) <15%. The distinction between BBP and other sources of BP, including common adulterants of pig bile powder (PBP), cattle bile powder (CBP), sheep bile powder (SBP), and chicken bile powder (CkBP), can be observed in the spectra. By using orthogonal partial least-squares discriminant analysis (OPLS-DA), more potential m/z markers were investigated. A BAs-related m/z marker of 498.3 was discovered as a typical differential molecular ion peak and was identified as tauroursodeoxycholic acid (TUDCA) and taurochenodeoxycholic acid (TCDCA) in BBP.

CONCLUSIONS

The proposed strategy has simple sample pretreatment steps and significantly shortened analysis time. As an emerging technology, chip-based nano-ESI-MS not only provides a reference for the rapid distinction of adulterated Chinese medicines, but also provides some insights into the identification of other chemicals and foods.

Bile acid-induced tissue factor activity in hepatocytes correlates with activation of farnesoid X receptor

Bile acids (BA) have been found to promote coagulation by increasing tissue factor (TF) activity. The contribution of elevated BA levels and cholestasis to TF decryption within the liver parenchyma and the role of farnesoid X receptor (FXR) in this process remain unclear. We investigated the effects of BA on TF activity and thrombin generation in hepatocytes and correlated these effects with activation of FXR-dependent signaling and apoptosis. HepG2 cells and primary hepatocytes were incubated with chenodeoxycholic acid (CDCA), glycochenodeoxycholic acid (GCDCA), ursodeoxycholic acid (UCDA), or the synthetic FXR agonist GW4064 for 24 h. MTT tests demonstrated cell viability throughout experiments. TF activity was tested via factor Xa generation and thrombin generation was measured by calibrated automated thrombography. Increased TF activity alongside enhanced thrombin generation was observed with CDCA and GW4064 but not with GCDCA and UDCA. TF activity was substantially reduced when FXR activation was blocked with the antagonist DY 268. Quantitative polymerase chain reaction revealed upregulation of FXR target genes only by CDCA and GW4064. Western blot analysis and fluorescence microscopy showed no TF overexpression arguing for TF decryption. Caspase 3 activity measurements and flow cytometric analysis of Annexin V binding showed no signs of apoptosis. Long-term exposure of hepatocytes to nontoxic BA may cause intracellular FXR overstimulation, triggering TF decryption irrespective of the amphiphilic properties of BA. The effect of BA on TF activation correlates with the molecule's ability to enter the cells and activate FXR. TF decryption occurs independently of apoptotic mechanisms.

Bile Acids, Liver Cirrhosis, and Extrahepatic Vascular Dysfunction

The bile acid pool with its individual bile acids (BA) is modulated in the enterohepatic circulation by the liver as the primary site of synthesis, the motility of the gallbladder and of the intestinal tract, as well as by bacterial enzymes in the intestine. The nuclear receptor farnesoid X receptor (FXR) and Gpbar1 (TGR5) are important set screws in this process. Bile acids have a vasodilatory effect, at least according to in vitro studies. The present review examines the question of the extent to which the increase in bile acids in plasma could be responsible for the hyperdynamic circulatory disturbance of liver cirrhosis and whether modulation of the bile acid pool, for example, via administration of ursodeoxycholic acid (UDCA) or via modulation of the dysbiosis present in liver cirrhosis could influence the hemodynamic disorder of liver cirrhosis. According to our analysis, the evidence for this is limited. Long-term studies on this question are lacking.

Transcutaneous Neuromodulation improved inflammation and sympathovagal ratio in patients with primary biliary ssscholangitis and inadequate response to Ursodeoxycholic acid: a pilot study

Background

At present, ursodeoxycholic acid (UDCA) is internationally recognized as a therapeutic drug in clinic. However, about 40% Primary Biliary Cholangitis (PBC) patients are poor responders to UDCA. It has been demonstrated that Transcutaneous Neuromodulation (TN) can be involved in gut motility, metabolism of bile acids, immune inflammation, and autonomic nerve. Therefore, this study aimed to explore the effect of TN combined with UDCA on PBC and related mechanisms.

Methods

According to inclusion and exclusion criteria, 10 healthy volunteers and 15 PBC patients were recruited to control group and TN group, respectively. PBC patients were alternately but blindly assigned to group A (TN combined with UDCA) and group B (sham-TN combined with UDCA), and a crossover design was used. The TN treatment was performed via the posterior tibial nerve and acupoint ST36 (Zusanli) 1 h twice/day for 2 weeks. T test and nonparametric test were used to analyze the data.

Results

1. TN combined with UDCA improved the liver function of PBC patients shown by a significant decrease of alkaline phosphatase and gamma-glutamyltransferase (γ-GT) (P < 0.05). 2. The treatment also decreased serum IL-6 levels (P < 0.05), but not the level of Tumor Necrosis Factor-α, IL-1β or IL-10. 3. TN combined with UDCA regulated autonomic function, enhanced vagal activity, and decreased the sympathovagal ratio assessed by the spectral analysis of heart rate variability (P < 0.05). 4. There was no change in 13 bile acids in serum or stool after TN or sham-TN.

Conclusions

TN cssombined with UDCA can significantly improve the liver function of PBC patients. It is possibly via the cholinergic anti-inflammatory pathway. TN might be a new non-drug therapy for PBC. Further studies are required.

Trial registration

The study protocol was registered in Chinese Clinical Trial Registry (number ChiCTR1800014633) on 25 January 2018.

Total bile acid to platelet ratio: A noninvasive index for predicting liver fibrosis in primary biliary cholangitis

The aim of the study was to develop a new early noninvasive diagnostic model for primary biliary cholangitis (PBC).A total of 118 PBC patients who had undergone a liver biopsy were enrolled in the study, and were randomized into a model group (78 patients) and a validation group (40 patients). The patients' histological stages were based on the classifications of the Scheuer's stage. All common parameters and liver pathological results were analyzed. And total bile acid to platelet ratio, aspartate aminotransferase to platelet ratio index, fibrosis index based on 4 factors and red cell distribution width to platelet ratio were calculated.There were 106 (89.8%) women and 12 men in this study, and the number of patients in Scheuer stage I, II, III, and IV hepatic fibrosis was 52 (44.1%), 36 (30.5%), 26 (22.0%), and 4 (3.4%), respectively. The areas under the receiver operating characteristic curves of the total bile acid to platelet ratio (TPR), the aspartate aminotransferase to platelet ratio index, the fibrosis index based on 4 factors , and the red cell distribution width to platelet ratio for predicting advanced liver fibrosis were 0.771, 0.715, 0.618, and 0.517 respectively. The areas under the receiver operating characteristic curves of the TPR was higher than other non-invasive serological models.As a simple, inexpensive and easily accessible non-invasive liver fibrosis diagnostic model, the TPR may be a new noninvasive marker for predicting histologic severity of PBC.

Serum Metabonomics Analysis of Liver Failure Treated by Nonbioartificial Liver Support Systems

OBJECTIVE

To analyze the small molecular metabolic compounds of nonbioartificial liver for treatment of hepatic failure and make further efforts to study the clinical efficacy, mechanism of action, and pathogenesis of hepatic failure.

METHODS

52 patients who met the standard of artificial liver treatment for liver failure were enrolled; these patients included 6 cases of acute liver failure (11.54%), 3 cases of subacute liver failure (5.77%), acute-on-chronic liver failure in 10 cases (19.23%), and 33 cases of chronic liver failure (63.46%). Treatment modes included plasma exchange in 34 patients (65.38%), bilirubin adsorption in 9 patients (17.31%), and hemofiltration in 9 patients (17.31%). The clinical efficacy of artificial liver was assessed by monitoring the effects in the near future. Significant changes in metabolic compounds of liver failure in the treatment before and after artificial liver were screened by using Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). Related metabolic pathways were analyzed by MetaboAnalyst.

RESULTS

After artificial liver treatment, the liver function and coagulation function of liver failure patients were significantly improved (P < 0.01), the Meld score was lower than that before treatment, and the difference was statistically significant (P < 0.05). Serum metabolomics identified 29 small metabolic compounds and 12 metabolic pathways with variable projection importance (VIP) greater than 1 before and after artificial liver treatment. There were 11 metabolic compounds of VIP over 1 and 7 metabolic pathways in the different modes of artificial liver treatment for chronic liver failure. Among them, bile acid metabolism, fatty acid metabolism, and amino acid metabolism are the main sources.

CONCLUSION

Artificial liver treatment can effectively improve liver function and blood coagulation function and Meld score, clinical symptoms and signs in patients with liver failure; the curative effect of artificial liver was verified, which reflected the clinical value of artificial liver in the treatment of liver failure. Artificial liver treatment of liver failure on fatty acids and primary bile acid synthesis pathway was the most significant. The difference of fatty acid, primary bile acid synthesis pathway, and phenylalanine metabolic pathway in different artificial liver patterns of chronic liver failure was the most significant. This provides a new basis for understanding the mechanism of hepatic failure and the mechanism of liver failure by artificial liver treatment.

Pharmacological interventions for primary biliary cholangitis: an attempted network meta-analysis

BACKGROUND

Primary biliary cholangitis (previously primary biliary cirrhosis) is a chronic liver disease caused by the destruction of small intra-hepatic bile ducts resulting in stasis of bile (cholestasis), liver fibrosis, and liver cirrhosis. The optimal pharmacological treatment of primary biliary cholangitis remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the treatment of primary biliary cholangitis through a network meta-analysis and to generate rankings of the available pharmacological interventions according to their safety and efficacy. However, it was not possible to assess whether the potential effect modifiers were similar across different comparisons. Therefore, we did not perform the network meta-analysis, and instead, assessed the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and randomised controlled trials registers to February 2017 to identify randomised clinical trials on pharmacological interventions for primary biliary cholangitis.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in participants with primary biliary cholangitis. We excluded trials which included participants who had previously undergone liver transplantation. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CI) using both fixed-effect and random-effects models based on available-participant analysis with Review Manager 5. We assessed risk of bias according to Cochrane, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 74 trials including 5902 participants that met the inclusion criteria of this review. A total of 46 trials (4274 participants) provided information for one or more outcomes. All the trials were at high risk of bias in one or more domains. Overall, all the evidence was low or very low quality. The proportion of participants with symptoms varied from 19.9% to 100% in the trials that reported this information. The proportion of participants who were antimitochondrial antibody (AMA) positive ranged from 80.8% to 100% in the trials that reported this information. It appeared that most trials included participants who had not received previous treatments or included participants regardless of the previous treatments received. The follow-up in the trials ranged from 1 to 96 months.The proportion of people with mortality (maximal follow-up) was higher in the methotrexate group versus the no intervention group (OR 8.83, 95% CI 1.01 to 76.96; 60 participants; 1 trial; low quality evidence). The proportion of people with mortality (maximal follow-up) was lower in the azathioprine group versus the no intervention group (OR 0.56, 95% CI 0.32 to 0.98; 224 participants; 2 trials; I2 = 0%; low quality evidence). However, it has to be noted that a large proportion of participants (25%) was excluded from the trial that contributed most participants to this analysis and the results were not reliable. There was no evidence of a difference in any of the remaining comparisons. The proportion of people with serious adverse events was higher in the D-penicillamine versus no intervention group (OR 28.77, 95% CI 1.57 to 526.67; 52 participants; 1 trial; low quality evidence). The proportion of people with serious adverse events was higher in the obeticholic acid plus ursodeoxycholic acid (UDCA) group versus the UDCA group (OR 3.58, 95% CI 1.02 to 12.51; 216 participants; 1 trial; low quality evidence). There was no evidence of a difference in any of the remaining comparisons for serious adverse events (proportion) or serious adverse events (number of events). None of the trials reported health-related quality of life at any time point.

FUNDING

nine trials had no special funding or were funded by hospital or charities; 31 trials were funded by pharmaceutical companies; and 34 trials provided no information on source of funding.

AUTHORS' CONCLUSIONS

Based on very low quality evidence, there is currently no evidence that any intervention is beneficial for primary biliary cholangitis. However, the follow-up periods in the trials were short and there is significant uncertainty in this issue. Further well-designed randomised clinical trials are necessary. Future randomised clinical trials ought to be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid post-randomisation dropouts or planned cross-overs; should have sufficient follow-up period (e.g. five or 10 years or more); and use clinically important outcomes such as mortality, health-related quality of life, cirrhosis, decompensated cirrhosis, and liver transplantation. Alternatively, very large groups of participants should be randomised to facilitate shorter trial duration.

Exploring potential biomarkers and determining the metabolic mechanism of type 2 diabetes mellitus using liquid chromatography coupled to high-resolution mass spectrometry

Diabetes mellitus has imposed a huge burden on modern society and is a serious threat to human health globally.

Ursodeoxycholic acid increases differentiation and mineralization and neutralizes the damaging effects of bilirubin on osteoblastic cells

BACKGROUND

Osteoporosis resulting from decreased bone formation is a common complication in patients with chronic cholestasis. Lithocholic acid (LCA) and bilirubin may play a role in osteoporosis given that both substances have detrimental effects on survival of human osteoblasts, the cells involved in bone formation.

AIMS

As ursodeoxycholic acid (UDCA) improves cholestasis, we have assessed if this bile acid may neutralize the harmful effects of LCA, bilirubin and sera from jaundiced patients on osteoblastic cells.

METHODS

The experiments were performed in primary human osteoblasts and human osteosarcoma cell line (Saos-2) at different times and concentrations of UDCA, LCA, cholic acid (CA), bilirubin and sera from jaundiced patients to assess cell viability, differentiation and mineralization.

RESULTS

UDCA significantly decreased cell survival at concentrations 10 times higher (1 mM) than that observed with LCA, whereas CA did not decrease osteoblast survival. UDCA (100 μM) neutralized the damaging effects of bilirubin (50 μM) and sera from jaundiced patients on survival. Moreover, UDCA (1 μM and 10 μM) increased osteoblast differentiation in cells treated with harmful concentrations of LCA or bilirubin. UDCA (100 μM) increased cell differentiation in osteoblasts cultured with a mix of serum from cholestatic patients by 23%. Furthermore, UDCA increased osteoblast mineralization by 35% and neutralized the negative consequences of 50 μM bilirubin.

CONCLUSIONS

UDCA increases osteoblast differentiation and mineralization, and neutralizes the detrimental effects of lithocholic acid, bilirubin and sera from jaundiced patients on osteoblastic cells. Therefore, UDCA may exert a favourable effect on bone in patients which chronic cholestasis.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Ursodeoxycholic acid is administered to patients with primary biliary cirrhosis, a chronic progressive inflammatory autoimmune-mediated liver disease with unknown aetiology. Despite its controversial effects, the U.S. Food and Drug Administration has approved its usage for primary biliary cirrhosis.

OBJECTIVES

To assess the beneficial and harmful effects of ursodeoxycholic acid in patients with primary biliary cirrhosis.

SEARCH METHODS

We searched for eligible randomised trials in The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, Clinicaltrials.gov, and the WHO International Clinical Trials Registry Platform. The literature search was performed until January 2012.

SELECTION CRITERIA

Randomised clinical trials assessing the beneficial and harmful effects of ursodeoxycholic acid versus placebo or 'no intervention' in patients with primary biliary cirrhosis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. Continuous data were analysed using mean difference (MD) and standardised mean difference (SMD). Dichotomous data were analysed using risk ratio (RR). Meta-analyses were conducted using both a random-effects model and a fixed-effect model, with 95% confidence intervals (CI). Random-effects model meta-regression was used to assess the effects of covariates across the trials. Trial sequential analysis was used to assess risk of random errors (play of chance). Risks of bias (systematic error) in the included trials were assessed according to Cochrane methodology bias domains.

MAIN RESULTS

Sixteen randomised clinical trials with 1447 patients with primary biliary cirrhosis were included. One trial had low risk of bias, and the remaining fifteen had high risk of bias. Fourteen trials compared ursodeoxycholic acid with placebo and two trials compared ursodeoxycholic acid with 'no intervention'. The percentage of patients with advanced primary biliary cirrhosis at baseline varied from 15% to 83%, with a median of 51%. The duration of the trials varied from 3 to 92 months, with a median of 24 months. The results showed no significant difference in effect between ursodeoxycholic acid and placebo or 'no intervention' on all-cause mortality (45/699 (6.4%) versus 46/692 (6.6%); RR 0.97, 95% CI 0.67 to 1.42, I² = 0%; 14 trials); on all-cause mortality or liver transplantation (86/713 (12.1%) versus 89/706 (12.6%); RR 0.96, 95% CI 0.74 to 1.25, I² = 15%; 15 trials); on serious adverse events (94/695 (13.5%) versus 107/687 (15.6%); RR 0.87, 95% CI 0.68 to 1.12, I² = 23%; 14 trials); or on non-serious adverse events (27/643 (4.2%) versus 18/634 (2.8%); RR 1.46, 95% CI 0.83 to 2.56, I² = 0%; 12 trials). The random-effects model meta-regression showed that the risk of bias of the trials, disease severity of patients at entry, ursodeoxycholic acid dosage, and trial duration were not significantly associated with the intervention effects on all-cause mortality, or on all-cause mortality or liver transplantation. Ursodeoxycholic acid did not influence the number of patients with pruritus (168/321 (52.3%) versus 166/309 (53.7%); RR 0.96, 95% CI 0.84 to 1.09, I² = 0%; 6 trials) or with fatigue (170/252 (64.9%) versus 174/244 (71.3%); RR 0.90, 95% CI 0.81 to 1.00, I² = 62%; 4 trials). Two trials reported the number of patients with jaundice and showed a significant effect of ursodeoxycholic acid versus placebo or no intervention in a fixed-effect meta-analysis (5/99 (5.1%) versus 15/99 (15.2%); RR 0.35, 95% CI 0.14 to 0.90, I² = 51%; 2 trials). The result was not supported by the random-effects meta-analysis (RR 0.56, 95% CI 0.06 to 4.95). Portal pressure, varices, bleeding varices, ascites, and hepatic encephalopathy were not significantly affected by ursodeoxycholic acid. Ursodeoxycholic acid significantly decreased serum bilirubin concentration (MD -8.69 µmol/l, 95% CI -13.90 to -3.48, I² = 0%; 881 patients; 9 trials) and activity of serum alkaline phosphatases (MD -257.09 U/L, 95% CI -306.25 to -207.92, I² = 0%; 754 patients, 9 trials) compared with placebo or no intervention. These results were supported by trial sequential analysis. Ursodeoxycholic acid also seemed to improve serum levels of gamma-glutamyltransferase, aminotransferases, total cholesterol, and plasma immunoglobulin M concentration. Ursodeoxycholic acid seemed to have a beneficial effect on worsening of histological stage (random; 66/281 (23.5%) versus 103/270 (38.2%); RR 0.62, 95% CI 0.44 to 0.88, I² = 35%; 7 trials).

AUTHORS' CONCLUSIONS

This systematic review did not demonstrate any significant benefits of ursodeoxycholic acid on all-cause mortality, all-cause mortality or liver transplantation, pruritus, or fatigue in patients with primary biliary cirrhosis. Ursodeoxycholic acid seemed to have a beneficial effect on liver biochemistry measures and on histological progression compared with the control group. All but one of the included trials had high risk of bias, and there are risks of outcome reporting bias and risks of random errors as well. Randomised trials with low risk of bias and low risks of random errors examining the effects of ursodeoxycholic acid for primary biliary cirrhosis are needed.

Primary biliary cirrhosis and bile acids

The dihydroxylated bile acid ursodeoxycholic acid (UDCA) has now been regarded for 20 years as the standard treatment for primary biliary cirrhosis (PBC), a chronic cholestatic immune-mediated condition marked by progressive destruction of small intrahepatic bile ducts, impaired biliary secretion, hepatocellular retention of toxic endogenous bile acids and, ultimately, the development of fibrosis leading to cirrhosis that commonly requires liver transplantation. At first sight, it seems intriguing that a bile acid could be considered for use as a therapeutic agent in a bile-acid secretion disorder. Yet, in addition to its inherently greater hydrophilic nature and competitive effect on endogenous bileacid recycling, UDCA has indeed been demonstrated to be a potent post-transcriptional secretagogue as well as a potential anti-inflammatory and anti-apoptotic agent. While the combined glucocorticoid receptor/pregnane X receptor (PXR) agonist budesonide, in combinaison with UDCA, has been shown to exert additional beneficial effects in PBC, significant progress in understanding the regulatory mechanisms involved in bile-acid homeostasis has led to the identification of nuclear [farnesoid X receptor (FXR), PXR, peroxisome proliferator-activated receptor alpha (PPARα)] and membrane (the membrane G protein-coupled bile acid receptor TGR5) receptors as critical pharmacological targets for future therapeutic approaches. Encouraging data from recent experimental and phase-II studies tend to confirm that the FXR agonist obeticholic acid and the PPARα agonists bezafibrate and fenofibrate may be used as add-on therapies in PBC patients with inadequate responses to UDCA or even as alternative first-line agents. These results could mark the beginning of a new therapeutic era for PBC.

Metabolomic profiling of 17 bile acids in serum from patients with primary biliary cirrhosis and primary sclerosing cholangitis: a pilot study

BACKGROUND

Primary biliary cirrhosis and primary sclerosing cholangitis are two cholestatic diseases characterised by hepatic accumulation of bile acids.

AIMS

This study compares serum bile acid levels in patients with primary biliary cirrhosis and primary sclerosing cholangitis and from age and sex-matched non cholestatic donors.

METHODS

Seventeen bile acids were quantified using liquid chromatography coupled to tandem mass spectrometry. Serum samples from cholestatic patients were compared with those of non-cholestatic donors.

RESULTS

The concentration of total bile acids, taurine and glycine conjugates of primary bile acids was elevated in both patients with primary biliary cirrhosis and primary sclerosing cholangitis when compared to non-cholestatic donors. Samples from primary sclerosing cholangitis patients displayed reduced levels of secondary acids, when compared to non cholestatic and primary biliary cirrhosis sera. The ratio of total glycine versus total taurine conjugates was reduced in patients with primary biliary cirrhosis, but not in primary sclerosing cholangitis.

CONCLUSION

The present study suggests that circulating bile acids are altered differentially in primary biliary cirrhosis and primary sclerosing cholangitis patients.

Ursodeoxycholic acid in cholestasis: linking action mechanisms to therapeutic applications

UDCA (ursodeoxycholic acid) is the therapeutic agent most widely used for the treatment of cholestatic hepatopathies. Its use has expanded to other kinds of hepatic diseases, and even to extrahepatic ones. Such versatility is the result of its multiple mechanisms of action. UDCA stabilizes plasma membranes against cytolysis by tensioactive bile acids accumulated in cholestasis. UDCA also halts apoptosis by preventing the formation of mitochondrial pores, membrane recruitment of death receptors and endoplasmic-reticulum stress. In addition, UDCA induces changes in the expression of metabolizing enzymes and transporters that reduce bile acid cytotoxicity and improve renal excretion. Its capability to positively modulate ductular bile flow helps to preserve the integrity of bile ducts. UDCA also prevents the endocytic internalization of canalicular transporters, a common feature in cholestasis. Finally, UDCA has immunomodulatory properties that limit the exacerbated immunological response occurring in autoimmune cholestatic diseases by counteracting the overexpression of MHC antigens and perhaps by limiting the production of cytokines by immunocompetent cells. Owing to this multi-functionality, it is difficult to envisage a substitute for UDCA that combines as many hepatoprotective effects with such efficacy. We predict a long-lasting use of UDCA as the therapeutic agent of choice in cholestasis.

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.

Biliary physiology and disease: reflections of a physician-scientist

A review is presented of Gustav Paumgartner's five decades of research and practice in hepatology focusing on biliary physiology and disease. It begins with studies of the excretory function of the liver including hepatic uptake of indocyanine green, bilirubin, and bile acids. The implications of these studies for diagnosis and understanding of liver diseases are pointed out. From there, the path of scientific research leads to investigations of hepatobiliary bile acid transport and the major mechanisms of bile formation. The therapeutic effects of the hydrophilic bile acid, ursodeoxycholic acid, have greatly stimulated these studies. Although ursodeoxycholic acid therapy for dissolution of cholesterol gallstones and some other nonsurgical treatments of gallstones were largely superseded by surgical techniques, ursodeoxycholic acid is currently considered the mainstay of therapy of some chronic cholestatic liver diseases, such as primary biliary cirrhosis. The major mechanisms of action of ursodeoxycholic acid therapy in cholestatic liver diseases are discussed. An attempt is made to illustrate how scientific research can lead to advances in medical practice that help patients.

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.

Pathogenesis and treatment of pruritus in cholestasis

Pruritus is an enigmatic, seriously disabling symptom accompanying cholestatic liver diseases and a broad range of other disorders. Most recently, novel itch-specific neuronal pathways, itch mediators and their relevant receptors have been identified. In addition, new antipruritic therapeutic strategies have been developed and/or are under evaluation. This review highlights recent experimental and clinical findings focusing on the pathogenesis and actual treatment of pruritus in cholestatic liver disease. Evidence-based therapeutic recommendations, including the use of anion exchange resins cholestyramine, colestipol and colesevelam, the microsomal enzyme inducer rifampicin, the opioid receptor antagonists naltrexone and naloxone, and the serotonin reuptake inhibitor sertraline, are provided.

Effect of ursodeoxycholic acid on liver function in children after successful surgery for biliary atresia

OBJECTIVES

Although ursodeoxycholic acid has been used to treat various cholestatic liver diseases in children, few data are available about its efficacy in biliary atresia. The aim of this study was to assess the effect of ursodeoxycholic acid treatment on liver function in children who underwent successful surgery for biliary atresia.

PATIENTS AND METHODS

We prospectively studied 16 children with biliary atresia who underwent successful portoenterostomies (postoperative conjugated bilirubin concentration: <34 micromol/L) and were treated with ursodeoxycholic acid for at least 18 months after surgery. Ursodeoxycholic acid treatment was then discontinued. Clinical and biological assessment was performed at the time of discontinuation of ursodeoxycholic acid treatment (T0), at follow-up (T1) and, if the clinical or biological status worsened, after resumption of ursodeoxycholic acid treatment (T2).

RESULTS

Ursodeoxycholic acid treatment was resumed in 13 cases. In 1 patient, jaundice recurred after ursodeoxycholic acid therapy was discontinued but abated after resumption of treatment. In 13 children, liver function worsened significantly when ursodeoxycholic acid was discontinued. T1 versus T0 concentrations expressed as multiples of the upper limit of the normal range (in parentheses) were as follows: alanine aminotransferase, 3.0 xN (0.8-7.0) vs 1.5 xN (0.5-5.4); gamma glutamyl transpeptidase, 8.0 xN (1.8-30.2) vs 4.2 xN (0.5-27.4); and aspartate aminotransferase, 1.7 xN (0.7-6.0) vs 1.3 xN (0.6-3.4). When ursodeoxycholic acid treatment was resumed, liver function had improved in all patients by T2. Concentrations of endogenous bile acids tended to be elevated at T1 (not significant) and were significantly decreased at T2.

CONCLUSION

Our study demonstrates the beneficial effect of ursodeoxycholic acid on liver function in children after successful surgery for biliary atresia.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis is an uncommon autoimmune liver disease with unknown aetiology. Ursodeoxycholic acid (UDCA) has been used for primary biliary cirrhosis, but the effects remain controversial.

OBJECTIVES

To evaluate the benefits and harms of UDCA on patients with primary biliary cirrhosis against placebo or no intervention.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials on The Cochrane Library, MEDLINE, EMBASE, SCI-EXPANDED, The Chinese Biomedical CD Database, LILACS, and the references of identified studies. The last search was performed in January 2007.

SELECTION CRITERIA

Randomised clinical trials evaluating UDCA versus placebo or no intervention in patients with primary biliary cirrhosis.

DATA COLLECTION AND ANALYSIS

The primary outcomes were mortality and mortality or liver transplantation. Binary outcomes were reported as odds ratio (OR) or relative risk (RR) and continuous outcomes as weighted mean difference, all with 95% confidence intervals (CI). Meta-regression was used to investigate the associations between UDCA effects and quality of the trial, UDCA dose, trial duration, and patient's severity of primary biliary cirrhosis. We also used Bayesian meta-analytic approach to estimate the UDCA effect as sensitivity analysis.

MAIN RESULTS

Sixteen randomised clinical trials evaluating UDCA against placebo or no intervention were identified. Data from three trials have been updated. Nearly half of the trials had high risk of bias. The combined results demonstrated no significant effects favouring UDCA on mortality (OR 0.97, 95% CI 0.67 to 1.42) and mortality or liver transplantation (RR 0.92, 95% CI 0.71 to 1.21). The findings were supported by the Bayesian meta-analyses. UDCA did not improve pruritus, fatigue, autoimmune conditions, liver histology, or portal pressure. UDCA seemed to improve biochemical variables, like serum bilirubin, ascites, and jaundice, but the findings were based on few trials with sparse data. The use of UDCA is significantly associated with adverse events, mainly weight gain.

AUTHORS' CONCLUSIONS

This systematic review did not demonstrate any benefit of UDCA on mortality and mortality or liver transplantation of patients with primary biliary cirrhosis. The few beneficial effects could not be due to random errors or outcome reporting bias.

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.

Identification of a novel 974C-->G nonsense mutation of the MRP2/ABCC2 gene in a patient with Dubin-Johnson syndrome and analysis of the effects of rifampicin and ursodeoxycholic acid on serum bilirubin and bile acids

Rifampicin (RIF) and ursodeoxycholic acid (UDCA) therapies have beneficial effects in chronic cholestatic diseases. These may result in part from the induction of multidrug-resistance protein 2 (MRP2/ABCC2) expression in the liver and kidney. However, the precise mechanisms by which RIF and UDCA act in cholestasis remain unclear. In the present study, we report the effects of chronic administration of both drugs in a patient with Dubin-Johnson syndrome (DJS), an inherited autosomal recessive disorder characterized by the absence of functional MRP2 protein at the canalicular hepatocyte membrane. A novel 974C-->G nonsense mutation was identified in the MRP2 gene sequence from this patient. RIF induced further increase in conjugated bilirubinemia, whereas concomitant administration of RIF and UDCA led to a dramatic rise in serum bile acid concentrations. These biochemical effects, which are in marked contrast to those observed in cholestatic settings, were concomitant with an increased MRP3, but not MRP4, expression on basolateral hepatocyte membrane. Such findings highlight the key role of MRP2 in the pharmacological properties of RIF and UDCA and suggest that both drugs should be used with caution in pathologic settings in which MRP2 expression may be downregulated, as in advanced stage of cholestatic diseases.

Medical treatment of cholestatic liver diseases: From pathobiology to pharmacological targets

Bile secretion is dependent on the coordinated functions of a number of hepatobiliary transport systems. Cholestasis may be caused by an impairment of bile secretion, an obstruction of bile flow or a combination of the two. The common consequence of all forms of cholestasis is retention of bile acids and other potentially toxic compounds in the hepatocytes leading to apoptosis or necrosis of hepatocytes and eventually to chronic cholestatic liver disease. In certain cholestatic disorders there is also leakage of bile acids into the peribiliary space causing portal inflammation and fibrosis. The following pharmacological targets for treatment of intrahepatic cholestasis can be identified: stimulation of orthograde biliary secretion and retrograde secretion of bile acids and other toxic cholephils into the systemic circulation for excretion via the kidneys to reduce their retention in the hepatocytes; stimulation of the metabolism of hydrophobic bile acids and other toxic compounds to more hydrophilic, less toxic metabolites; protection of injured cholangiocytes against toxic effects of bile; inhibition of apoptosis caused by elevated levels of cytotoxic bile acids; inhibition of fibrosis caused by leakage of bile acids into the peribiliary space. The clinical results of ursodeoxcholic acid therapy of primary biliary cirrhosis may be regarded as the first success of this strategy.

Ursodeoxycholic acid treatment of vanishing bile duct syndromes

Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Ursodeoxycholic acid (UDCA), a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.

Granulomatous liver disease and cholestasis

Development of hepatic granulomas, especially those located within portal tracts, is associated with injury to septal and interlobular bile ducts. Dysfunction of the bile ducts in turn leads to cholestasis,and ongoing damage by the granulomatous inflammation eventually results in ductopenia. A multitude of causes of hepatic granulomas have been described over the last few decades. Diligent and prioritized search for cause of hepatic granulomas should proceed within the environmental and epidemiologic context of a given patient. The therapeutic approaches, including amelioration of the cholestatic syndrome, are often determined by successful identification of specific etiologic factors causing the granulomas in the liver.

Mechanisms of action and therapeutic efficacy of ursodeoxycholic acid in cholestatic liver disease

Ursodeoxycholic acid (UDCA) is widely used for the treatment of cholestatic liver diseases. Multiple mechanisms of action of UDCA have been described aiming at one or more of the pathogenetic processes of cholestatic liver diseases: (1) protection of injured cholangiocytes against toxic effects of bile acids, (2) stimulation of impaired biliary secretion, (3) stimulation of detoxification of hydrophobic bile acids, and (4) inhibition of apoptosis of hepatocytes. Through one or more of these mechanisms, UDCA slows the progression of primary biliary cirrhosis and improves a number of other cholestatic disorders.

Systematic review: ursodeoxycholic acid--adverse effects and drug interactions

BACKGROUND

Ursodeoxycholic acid is increasingly being used for the treatment of chronic cholestatic liver diseases. It appears to be generally well tolerated, but a systematic review on drug safety is lacking.

AIM

As experimental data suggest a role of bile acids in the regulation of hepatic drug metabolism at both the transcriptional and post-transcriptional level, the literature was screened for adverse drug reactions and drug interactions related to ursodeoxycholic acid.

METHODS

A systematic review of the literature was performed using a refined search strategy to evaluate the adverse effects of ursodeoxycholic acid and its interactions with other drugs.

RESULTS

Ursodeoxycholic acid caused diarrhoea in a small proportion of patients. Rare skin reactions were due to drug adjuvants rather than the active substance. Decompensation of liver cirrhosis was reported after the administration of ursodeoxycholic acid in single cases of end-stage primary biliary cirrhosis. Recurrent right upper quadrant abdominal pain was incidentally observed. The absorption of ursodeoxycholic acid was impaired by colestyramine, colestimide, colestipol, aluminium hydroxide and smectite. Metabolic drug interactions were reported for the cytochrome P4503A substrates, ciclosporin, nitrendipine and dapsone.

CONCLUSIONS

Ursodeoxycholic acid is generally well tolerated. Drug absorption interactions with anion exchange resins deserve consideration. Metabolic interactions with compounds metabolized by cytochrome P4503A are to be expected.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic cholestatic liver disease of adults. This disorder is characterised histologically by chronic non-suppurative destruction of interlobular bile ducts leading to advanced fibrosis, cirrhosis, and liver failure. The precise aetiopathogenesis of primary biliary cirrhosis remains unknown, although dysregulation of the immune system and genetic susceptibility both seem to be important. Affected patients are typically middle-aged women with abnormal serum concentrations of alkaline phosphatase. Presence of antimitochondrial antibody in serum is almost diagnostic of the disorder. Identification of primary biliary cirrhosis is important, because effective treatment with ursodeoxycholic acid has been shown to halt disease progression and improve survival without need for liver transplantation. However, therapeutic options for disease-related complications-including fatigue and metabolic bone disease-remain unavailable. Mathematical models have been developed that accurately predict the natural history of primary biliary cirrhosis in individuals. Despite advances in understanding of the disease, it remains one of the major indications for liver transplantation worldwide.

A randomized controlled trial of ursodeoxycholic acid in patients with alcohol-induced cirrhosis and jaundice

The aim of our multicenter study was to assess the efficacy of ursodeoxycholic acid (UDCA) on the survival of patients with alcohol-induced cirrhosis and jaundice. We included patients with histologically proven alcohol-induced cirrhosis and serum bilirubin >50 micromol/L. After randomization, patients received either UDCA (13-15 mg/kg/d) or a placebo for 6 months. Two hundred twenty-six patients (113 in each group) were included in 24 centers. There were 139 men and 87 women, mean age of 50.3 years. Seventy-four percent had associated alcohol-induced hepatitis, and 24% received a corticosteroid therapy. At inclusion, the 2 groups were comparable for the main clinical and biologic parameters, but serum bilirubin was higher in the UDCA group than in the placebo group (163 micromol/L vs. 145 micromol/L, P <.03). The percentage of patients lost at follow-up or who resumed their alcoholism during the study was comparable in the 2 groups. During the study, 55 patients died, 35 in the UDCA group and 20 in the placebo group. In the intention to treat analysis, the probability of survival at 6 months (Kaplan-Meier method) was lower in the UDCA than in the P group (69% vs. 82%, respectively; P =.04, log-rank test). After adjustment on the bilirubin level at entry (Cox model), the independent predictive value of the treatment group did not reach the statistical level (RR = 1.64, CI 0.85-2.85; P =.077). In conclusion, UDCA administered at the dose recommended in primary biliary cirrhosis has no beneficial effect on the 6-month survival of patients with severe alcohol-induced cirrhosis. An inappropriate dosage of UDCA cannot be excluded as an explanation for the lack of therapeutic benefit.

Pregnancy in a patient with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic syndrome that is characterized by fibrosing inflammatory destruction of intra- and/or extrahepatic biliary ducts. The etiology is unknown and there is no known effective treatment. The course of PSC is quite variable; however, the disease is typically slowly progressive. There is little known regarding the natural history and potential complications of pregnancy in a patient with PSC. This case report details a 36-year-old woman with PSC who became pregnant. The pregnancy was complicated by the development of dominant stricture. A healthy baby boy was delivered at 33.5 weeks. The mother required cholangiography and stent placement immediately after delivery, but her postpartum course was otherwise unremarkable.

Ursodeoxycholic acid in cholestatic liver disease: mechanisms of action and therapeutic use revisited

Ursodeoxycholic acid (UCDA) is increasingly used for the treatment of cholestatic liver diseases. Experimental evidence suggests three major mechanisms of action: (1) protection of cholangiocytes against cytotoxicity of hydrophobic bile acids, resulting from modulation of the composition of mixed phospholipid-rich micelles, reduction of bile acid cytotoxicity of bile and, possibly, decrease of the concentration of hydrophobic bile acids in the cholangiocytes; (2) stimulation of hepatobiliary secretion, putatively via Ca(2+)- and protein kinase C-alpha-dependent mechanisms and/or activation of p38(MAPK) and extracellular signal-regulated kinases (Erk) resulting in insertion of transporter molecules (e.g., bile salt export pump, BSEP, and conjugate export pump, MRP2) into the canalicular membrane of the hepatocyte and, possibly, activation of inserted carriers; (3) protection of hepatocytes against bile acid-induced apoptosis, involving inhibition of mitochondrial membrane permeability transition (MMPT), and possibly, stimulation of a survival pathway. In primary biliary cirrhosis, UDCA (13-15 mg/kg/d) improves serum liver chemistries, may delay disease progression to severe fibrosis or cirrhosis, and may prolong transplant-free survival. In primary sclerosing cholangitis, UDCA (13-20 mg/kg/d) improves serum liver chemistries and surrogate markers of prognosis, but effects on disease progression must be further evaluated. Anticholestatic effects of UDCA have also been reported in intrahepatic cholestasis of pregnancy, liver disease of cystic fibrosis, progressive familial intrahepatic cholestasis, and chronic graft-versus-host disease. Future efforts will focus on definition of additional clinical uses of UDCA, on optimized dosage regimens, as well as on further elucidation of mechanisms of action of UDCA at the molecular level.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis is a rare autoimmune liver disease and an effective treatment has been difficult to establish. Some randomised clinical trials have found an effect of ursodeoxycholic acid for primary biliary cirrhosis.

OBJECTIVES

Evaluate the beneficial effects and adverse effects of peroral ursodeoxycholic acid for primary biliary cirrhosis versus placebo or no intervention.

SEARCH STRATEGY

The Controlled Trials Register of The Cochrane Hepato-Biliary Group, The Cochrane Library, MEDLINE, EMBASE and the full text of the identified studies were searched until April 2001. The electronic searches were done by entering the search terms 'ursodeoxycholic acid', 'UDCA', 'primary biliary cirrhosis', and 'PBC'.

SELECTION CRITERIA

Randomised clinical trials evaluating ursodeoxycholic acid administered perorally at any dose versus placebo or no intervention in patients with primary biliary cirrhosis diagnosed by any method. Only trials using an adequate method for randomisation were included, regardless of blinding and language.

DATA COLLECTION AND ANALYSIS

The methodologic quality of the randomised clinical trials was evaluated by components and the Jadad-score. The following outcomes were extracted: mortality, liver transplantation, pruritus, other clinical symptoms (jaundice, portal pressure, (bleeding) oesophageal varices, ascites, hepatic encephalopathy, hepato-renal syndrome, autoimmune conditions), liver biochemistry, liver function, liver biopsy findings, quality of life, and adverse events. All analyses were performed according to the intention-to-treat method.

MAIN RESULTS

A total of 16 randomised clinical trials evaluating ursodeoxycholic acid against placebo (n = 15) or no intervention (n = 1) in 1422 patients were identified. The median Jadad-score was 3 (range 1-5). A number of trials described as double blind had problems with the blinding. Neither mortality (odds ratio = 0.94; 95% confidence interval (CI) 0.60 to 1.48), liver transplantation (odds ratio = 0.83; 95% CI 0.52 to 1.32), mortality or liver transplantation (odds ratio = 0.90; 95% CI 0.65 to 1.26), pruritus, fatigue, autoimmune conditions, quality of life, liver histology, or portal pressure were significantly affected by ursodeoxycholic acid (given in doses of 8-15 mg/kg/day for three months to five years). However, ursodeoxycholic acid significantly (P < 0.05) reduced ascites, jaundice, and biochemical variables such as serum bilirubin and liver enzymes. Ursodeoxycholic acid was not significantly associated with adverse events. Including data after patients had been switched onto open label ursodeoxycholic acid confirmed the findings regarding the lack of a significant effect of ursodeoxycholic acid on mortality and mortality or liver transplantation. A significant (P = 0.04) effect was, however, observed on the incidence of liver transplantation (odds ratio = 0.68; 95% CI 0.48 to 0.98).

REVIEWER'S CONCLUSIONS

Ursodeoxycholic acid has a marginal therapeutic effect for primary biliary cirrhosis. On the positive side, ursodeoxycholic acid has few side effects. The general usage of ursodeoxycholic acid for primary biliary cirrhosis needs reevaluation.

Incomplete response to ursodeoxycholic acid in primary biliary cirrhosis: is a double dosage worthwhile?

OBJECTIVE

The aim of this study was to assess the safety and efficacy of high-dose ursodeoxycholic acid (UDCA, 28-32 mg/kg/day) in patients with primary biliary cirrhosis (PBC) who had shown an incomplete response to the standard dose (13-15 mg/kg/day).

METHODS

A total of 25 patients with PBC who had been on UDCA (13-15 mg/kg/day) therapy for 24-141 months and had shown persistent elevation of ALP activity at least two times the upper limit of normal were enrolled. The dose of UDCA was increased to 30 (28-32) mg/kg/day and given for 1 yr.

RESULTS

A significant but marginal improvement in serum ALP activity (707+/-52 vs 571+/-32, p = 0.001) was noted at 1 yr of treatment with high-dose UDCA. However, levels of total bilirubin (1.1+/-0.2 vs 1.0+/-0.2, p = 0.1), AST (58+/-9 vs 54+/-1, p = 0.1), albumin (4.1+/-0.7 vs 4.0+/-0.08, p = 0.1), or Mayo risk score (4.13+/-0.3 vs 4.12+/-0.3, p = 0.2) remained essentially unchanged. Normalization of liver tests did not occur in any patient, and adverse events were not recorded in any case.

CONCLUSIONS

Although UDCA at a dose of 28-32 mg/kg/day is well tolerated, this dosage does not seem to benefit most patients with PBC responding incompletely to a dose of 13-15 mg/kg/day. The results of this pilot study would seem to discourage further controlled trials of high-dose UDCA in suboptimal responders to the standard dose of UDCA.

The therapeutic effects of ursodeoxycholic acid as an anti-apoptotic agent

The dihydroxy bile acid, ursodeoxycholic acid (UDCA), has been in widespread clinical use in the Western world since the mid 1980s, when it was initially used for gallstone dissolution [1,2] and subsequently for the treatment of chronic cholestatic liver diseases [3,4]. Many clinical trials of UDCA in a variety of cholestatic disorders established biochemical and clinical improvements, and most importantly showed a significant prolongation of transplant-free survival after four years of treatment with UDCA in patients with primary biliary cirrhosis [5]. Despite its clinical efficacy, the precise mechanism(s) by which UDCA improves liver function during cholestasis is still a matter of debate [6]. It was initially considered that the choleretic effect of UDCA, coupled with its ability to cause a marked shift in the composition of the bile acid pool towards hydrophilicity, accounted for its mechanism of action. In recent years, however, it has become evident that UDCA and its conjugated derivatives are capable of exerting direct effects at the cellular, subcellular, and molecular levels by stabilising cell membranes, affecting signal transduction pathways, and regulating immune responses. In addition, we have shown that UDCA plays a unique role in modulating the apoptotic threshold in both hepatic and non-hepatic cells [7-10]. The purpose of this article is to examine the mechanism(s) by which UDCA prevents apoptotic cell death associated with cholestasis. In addition, we will also review a potentially novel and, heretofore, unrecognised role of UDCA as a therapeutic agent in the treatment of non-liver diseases associated with increased levels of apoptosis as a pathogenesis of the disorder.

Progressive familial intrahepatic cholestasis. Genetic basis and treatment

Major advances in the understanding of the molecular mechanisms of bile formation and genetic studies of children with chronic cholestasis uncovered the molecular basis of PFIC. Specific defects in the FIC1, BSEP, and MDR3 genes are responsible for distinct PFIC phenotypes. These findings have confirmed the autosomal recessive inheritance of the disease and now provide specific diagnostic tools for the investigation of children with PFIC. This understanding should also allow prenatal diagnosis in the future. Identification of mutations in these genes will allow genotype-phenotype correlations to be defined within the spectrum of PFIC. These correlations performed in patients previously treated by UDCA or biliary diversion should identify those PFIC patients who could benefit from these therapies. In the future, other therapies, such as cell and gene therapies, might represent an alternative to liver transplantation. It remains to be determined if defects in the FIC1, BSEP, and MDR3 genes are responsible for all types of PFIC, or if other yet undiscovered genes, possibly involved in bile formation or its regulation, may be involved in the pathogenesis of PFIC.

Mechanisms of cholestasis

From the multiple mechanisms of cholestasis presented in this article, a unifying hypothesis may be deduced by parsimony. The disturbance of the flow of bile must inevitably lead to the intracellular retention of biliary constituents. Alternatively, the lack of specific components of bile unmasks the toxic potential of other components, as in the case of experimental mdr2 deficiency. In the sequence of events that leads to liver injury, the cytotoxic action of bile salts is pivotal to all forms of cholestasis. The inhibition of the bsep by drugs, sex steroids, or monohydroxy bile salts is an example of direct toxicity to the key mediator in canalicular bile salt excretion. In other syndromes, the dysfunction of distinct hepatocellular transport systems is the primary pathogenetic defect leading to cholestasis. Such dysfunctions include the genetic defects in PFIC and the direct inhibition of gene transcription by cytokines. Perturbations in the short-term regulation of transport protein function are exemplified by the cholestasis of endotoxinemia. The effect of bile salts on signal transduction, gene transcription, and transport processes in hepatocytes and cholangiocytes has become the focus of intense research in recent years. The central role of bile salts in the pathogenesis of cholestasis has, ironically, become all the more evident from the improvement of many cholestatic syndromes with oral bile salt therapy.

Ursodeoxycholic acid therapy in hepatobiliary disease

Ursodeoxycholic acid is a hydrophilic bile acid that under normal circumstances represents a small fraction of the bile acid pool in humans. It is effective in dissolving cholesterol gallstones in appropriately selected patients. Ursodeoxycholic acid improves serum alkaline phosphatase and aminotransferase levels in primary biliary cirrhosis, but its effects on rates of liver transplantation and death are less certain. Ursodeoxycholic acid has had promising [corrected] effects in several other cholestatic liver diseases, such as cystic fibrosis and intrahepatic cholestasis of pregnancy, but data are too preliminary to make recommendations about its routine use in these conditions. Its effects are mediated by amelioration of damage to cell membranes caused by retained toxic bile acids. Ursodeoxycholic acid improves biliary secretion of bile acids, may improve bile flow, and it has immunomodulatory properties that may reduce immune-mediated liver damage. However, its use in the treatment of cholestatic liver disease remains uncertain pending additional randomized trials.

Chronic cholestatic diseases

Chronic cholestatic diseases, whether occurring in infancy, childhood or adulthood, are characterized by defective bile acid transport from the liver to the intestine, which is caused by primary damage to the biliary epithelium in most cases. In this article, approaches to diagnosis and management of the main specific disorders are provided and some of the recent developments in this field are discussed. Major advances in the understanding of the cellular and molecular physiology of bile secretion have led to identification of genetic defects responsible for the different types of progressive familial intrahepatic cholestasis (PFIC). The potential role of the genes involved in PFIC in some adult cholestatic disorders remains to be determined. The majority of adult patients with chronic cholestasis have primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC). Recently, variant forms of PBC have been described. The term autoimmune cholangitis is used to describe patients having chronic non-suppurative cholangitis with negative antimitochondrial antibodies (AMA) but positive antinuclear and/or antismooth muscle antibodies. Autoimmune cholangitis and AMA-positive PBC are quite similar in terms of clinical presentation, survival and response to ursodeoxycholic acid (UDCA) therapy. In contrast, autoimmune cholangitis must be distinguished from PBC-autoimmune hepatitis (AIH) overlap syndrome in which biochemical and histological characteristics of both PBC and AIH coexist. Combination of UDCA and corticosteroids is required in most patients with overlap syndrome to obtain a complete clinical and biochemical response. Long-term UDCA treatment improves survival without liver transplantation in PBC patients. Among the putative mechanisms of the beneficial effects of UDCA, description of anti-apoptotic properties and effect on endotoxin disposal in biliary cells have provided new insights. In patients with incomplete response to UDCA, combination of UDCA with antiinflammatory or immunosuppressive drugs is under evaluation. Variant forms of PSC have also been described, including PSC-AIH overlap syndrome, especially in children or young adults, and small-duct PSC, which is characterized by normal cholangiogram in patients having chronic cholestasis, histologic features compatible with PSC and inflammatory bowel disease. Development of cholangiocarcinoma (CC) is a major feature of PSC, occurring in 10-15% of patients. Early diagnosis of CC is a difficult challenge, although positron emission tomography seems a promising tool. Unlike PBC, effective medical therapy is not yet available in PSC, reflecting the lack of knowledge about the exact pathogenesis of the disease. Currently, liver transplantation is the only effective therapy for patients with advanced disease, although recurrence of PSC in the graft may occur.

Primary biliary cirrhosis: new perspectives in diagnosis and treatment

Primary biliary cirrhosis (PBC) is a chronic autoimmune disease characterised by cholestatic liver function tests, antimitochondrial antibodies, and abnormal liver histology. Early descriptions of a rare rapidly progressive disease no longer reflect the more indolent progress often seen today. Many patients have significant long term morbidity through symptoms such as fatigue and itch with a minority progressing to liver failure and need for transplantation. The current data on the diagnosis, clinical progression, and treatment of PBC are reviewed.

Review article: mechanisms of action and therapeutic applications of ursodeoxycholic acid in chronic liver diseases

Ursodeoxycholic acid (ursodiol) is a non-toxic, hydrophilic bile acid used to treat predominantly cholestatic liver disorders. Better understanding of the cellular and molecular mechanisms of action of ursodeoxycholic acid has helped to elucidate its cytoprotective, anti-apoptotic, immunomodulatory and choleretic effects. Ursodeoxycholic acid prolongs survival in primary biliary cirrhosis and it improves biochemical parameters of cholestasis in various other cholestatic disorders including primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, cystic fibrosis and total parenteral nutrition-induced cholestasis. However, a positive effect on survival remains to be established in these diseases. Ursodeoxycholic acid is of unproven efficacy in non-cholestatic disorders such as acute rejection after liver transplantation, non-alcoholic steatohepatitis, alcoholic liver disease and chronic viral hepatitis. This review outlines the present knowledge of the modes of action of ursodeoxycholic acid, and presents data from clinical trials on its use in chronic liver diseases.

Intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy is one of the primary disorders of the liver that adversely affects maternal well-being and fetal outcome. Early identification of this condition, careful interdisciplinary monitoring, and prompt delivery at fetal maturity can improve outcomes in the mother and child. Although the cause is unclear, IHCP probably arises from a genetic predisposition for increased sensitivity to estrogens and progestogens and altered membrane composition and expression of bile ducts, hepatocytes, and canalicular transport systems. As a result, the elevations in maternal levels of bile acids and their molar ratios seen in healthy pregnancy rise further in IHCP patients. Also, as the normal fetal-to-maternal transfer of bile acids across the trophoblast is impaired, the excess bile acids with abnormal profiles accumulate and are toxic to the fetus. The management of IHCP is dictated by the increased risks of fetal distress, spontaneous preterm delivery, and sudden death, as well as by alleviating pruritus in the mother. These risks to the fetus rise progressively to delivery, regardless of serum levels of bile acids and ALT. Close monitoring of these markers is essential but does not prevent sudden fetal distress and death. Provision should be made to induce labor as soon as fetal lung maturity has been established. Ursodeoxycholic acid is the only therapy that has proven effective, albeit in small studies, in alleviating pruritus and restoring towards normal the abnormal profiles of bile acids and sulfated steroids in serum and other body fluids. Ursodeoxycholic acid seems to have no obvious adverse effects on the fetus, but experience is insufficient to draw conclusions regarding teratogenicity and prevention of adverse outcomes.