Intragastric administration of ursodeoxycholic acid suppresses immunoglobulin secretion by lymphocytes from liver, but not from peripheral blood, spleen or Peyer's patches in mice

Bile acids for primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis is a progressive chronic cholestatic liver disease that usually leads to the development of cirrhosis. Studies evaluating bile acids in the treatment of primary sclerosing cholangitis have shown a potential benefit of their use. However, no influence on patients survival and disease outcome has yet been proven.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for patients with primary sclerosing cholangitis.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Library, MEDLINE, EMBASE and Science Citation Index Expanded generally from inception through to October 2010.

SELECTION CRITERIA

Randomised clinical trials comparing any dose of bile acids or duration of treatment versus placebo, no intervention, or another intervention were included irrespective of blinding, language, or publication status.

DATA COLLECTION AND ANALYSIS

Two authors extracted data independently. We evaluated the risk of bias of the trials using prespecified domains. We performed the meta-analysis according to the intention-to-treat principle. We presented outcomes as relative risks (RR) or mean differences (MD), both with 95% confidence intervals (CI).

MAIN RESULTS

Eight trials evaluated ursodeoxycholic acid versus placebo or no intervention (592 patients). The eight randomised clinical trials have a high risk of bias. Patients were treated for three months to six years (median three years). The dosage of ursodeoxycholic acid used in the trials ranged from low (10 mg/kg body weight/day) to high (28 to 30 mg/kg body weight/day). Ursodeoxycholic acid did not significantly reduce the risk of death (RR 1.00; 95% CI 0.46 to 2.20); treatment failure including liver transplantation, varices, ascites, and encephalopathy (RR 1.22; 95% CI 0.91 to 1.64); liver histological deterioration (RR 0.89; 95% CI 0.45 to 1.74); or liver cholangiographic deterioration (RR 0.60; 95% CI 0.23 to 1.57). Ursodeoxycholic acid significantly improved serum bilirubin (MD -14.6 µmol/litre; 95% CI -18.7 to -10.6), alkaline phosphatases (MD -506 IU/litre; 95% CI -583 to -430), aspartate aminotransferase (MD -46 IU/litre; 95% CI -77 to -16), and gamma-glutamyltranspeptidase (MD -260 IU/litre; 95% CI -315 to -205), but not albumin (MD -0.20 g/litre; 95% CI -1.91 to 1.50). Ursodeoxycholic acid was safe and well tolerated by patients with primary sclerosing cholangitis.

AUTHORS' CONCLUSIONS

We did not find enough evidence to support or refute the use of bile acids in the treatment of primary sclerosing cholangitis. However, bile acids seem to lead to a significant improvement in liver biochemistry. Therefore, more randomised trials are needed before any of the bile acids can be recommended for this indication.

Bile acids for liver-transplanted patients

BACKGROUND

Liver transplantation has become a widely accepted form of treatment for numerous end-stage liver diseases. Bile acids may decrease allograft rejection after liver transplantation by changing the expression of major histocompatibility complex class molecules in bile duct epithelium and central vein endothelium.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for liver-transplanted patients.

SEARCH STRATEGY

We performed searches of The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Expanded to September, 2009.

SELECTION CRITERIA

Randomised clinical trials comparing any dose of bile acids or duration of treatment in liver-transplanted patients versus placebo, no intervention, or another intervention. We included randomised clinical trials irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

Two review authors extracted and checked data independently. We evaluated the risk of bias of the trials from the method of allocation sequence generation, allocation concealment, blinding, outcome data analysis, outcome data reporting, and other potential sources of bias. We used the intention-to-treat principle to perform meta-analyses and presented the outcomes as relative risks (RR) or mean differences (MD), both with 95% confidence intervals (CI).

MAIN RESULTS

The updated search resulted in no new trials meeting the inclusion criteria of this review, thus leaving it to the seven already included randomised trials (six evaluating ursodeoxycholic acid versus placebo or no intervention, and one evaluating tauro-ursodeoxycholic acid versus no intervention) enrolling a total of 335 participants. The administration of bile acids began one day or more after liver transplantation. All patients received the standard triple-drug immunosuppressive regimen (steroids, azathioprine, and cyclosporine or tacrolimus) to suppress the allograft rejection response after liver transplantation. Bile acids compared with placebo or no intervention did not significantly change all-cause mortality (RR 0.85, 95% CI 0.53 to 1.36), mortality related to allograft rejection (RR 0.30, 95% CI 0.01 to 7.12), retransplantation (RR 0.76, 95% CI 0.20 to 2.86), acute cellular rejection, or number of patients with steroid-resistant rejection. Bile acids significantly reduced the number of patients who had chronic rejection in a fixed-effect model but not in a random-effects model meta-analysis. Bile acids were safe and well tolerated by liver-transplanted patients. However, this observation is based on data analysis from three trials with only 187 patients.

AUTHORS' CONCLUSIONS

We did not find evidence to support or refute bile acids for liver-transplanted patients. Further randomised trials are necessary before bile acids can be recommended to liver-transplanted patients.

Bile-acid-induced cell injury and protection

Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids (BAs) in cholestatic diseases. BAs may disrupt cell membranes through their detergent action on lipid components and can promote the generation of reactive oxygen species that, in turn, oxidatively modify lipids, proteins, and nucleic acids, and eventually cause hepatocyte necrosis and apoptosis. Several pathways are involved in triggering hepatocyte apoptosis. Toxic BAs can activate hepatocyte death receptors directly and induce oxidative damage, thereby causing mitochondrial dysfunction, and induce endoplasmic reticulum stress. When these compounds are taken up and accumulate inside biliary cells, they can also cause apoptosis. Regarding extrahepatic tissues, the accumulation of BAs in the systemic circulation may contribute to endothelial injury in the kidney and lungs. In gastrointestinal cells, BAs may behave as cancer promoters through an indirect mechanism involving oxidative stress and DNA damage, as well as acting as selection agents for apoptosis-resistant cells. The accumulation of BAs may have also deleterious effects on placental and fetal cells. However, other BAs, such as ursodeoxycholic acid, have been shown to modulate BA-induced injury in hepatocytes. The major beneficial effects of treatment with ursodeoxycholic acid are protection against cytotoxicity due to more toxic BAs; the stimulation of hepatobiliary secretion; antioxidant activity, due in part to an enhancement in glutathione levels; and the inhibition of liver cell apoptosis. Other natural BAs or their derivatives, such as cholyl-N-methylglycine or cholylsarcosine, have also aroused pharmacological interest owing to their protective properties.

Long-term treatment of chronic hepatitis C with ursodeoxycholic acid: influence of HCV genotypes and severity of liver disease

AIMS/BACKGROUND

Current therapy for chronic hepatitis C virus (HCV) infection is based on the administration of interferon alpha (IFN) alone or in combination with other anti-viral agents. However, such therapy is effective in only a minority of selected patients. Long-term ursodeoxycholic acid (UDCA) treatment has been reported to improve liver function and structure especially in cholestatic disorders. We investigated the effect of long-term UDCA treatment on liver function in respect to the severity of chronic liver disease and HCV genotypes.

METHODS

Forty-five patients with non-cholestatic laparoscopy-biopsy proven HCV-associated chronic hepatitis (n=16) or cirrhosis (n=29) who had not responded to, or were unsuitable for IFN, were randomly assigned to receive UDCA (600 mg/day; n=23) or no therapy (n=22) for 12 months. At entry, all patients were evaluated by means of conventional and quantitative liver function tests (LFTs), including galactose elimination capacity and antipyrine clearance, HCV antibodies, HCV-RNA and HCV genotypes. LFTs were measured at 6 and at 12 months, whereas HCV-RNA was determined again after treatment.

RESULTS

Baseline characteristics were comparable in the two study groups. Long-term UDCA therapy was well tolerated. Based on the analysis of variance, there was a significant decrease in serum transaminase, LDH and GGT levels in UDCA treated patients. By contrast, the activities of these enzymes increased in untreated patients, with AST levels reaching statistical significance only. Statistical analysis also showed that the improvement in biochemical markers was more pronounced in UDCA treated patients with liver cirrhosis than in those with chronic hepatitis but was similar in patients with HCV genotype 1b and non-1b. However, HCV-RNA was positive in all patients after treatment. Quantitative LFTs remained, on average, stable over the 12 months of the trial in all groups.

CONCLUSIONS

Long-term UDCA treatment is well tolerated in patients with HCV-associated chronic liver disease. The effect appears to be greater in cirrhotics than in patients with chronic hepatitis but is independent of HCV genotypes. Thus, long-term UDCA treatment, despite the absence of an anti-viral effect, seems beneficial in reducing disease activity in patients with chronic hepatitis or cirrhosis who are unsuitable for IFN therapy.