Effect of Rifampicin on the Plasma Concentrations of Bile Acid-O-Sulfates in Monkeys and Human Liver-Transplanted Chimeric Mice With or Without Bile Flow Diversion.

The present study examined the significance of enterohepatic circulation and the effect of rifampicin [an inhibitor of organic anion-transporting polypeptide 1B (OATP1B)] on the plasma concentrations of bile acid-O-sulfates (glycochenodeoxycholate-O-sulfate, lithocholate-O-sulfate, glycolithocholate-O-sulfate, and taurolithocholate-O-sulfate) in monkeys and human liver-transplanted chimeric mice (PXB mouse). Rifampicin significantly increased the area under the curve of bile acid-O-sulfates in monkeys (13-69 times) and PXB mice (13-25 times) without bile flow diversion. Bile flow diversion reduced the concentration of plasma bile acid-O-sulfates under control conditions in monkeys and the concentration of plasma glycochenodeoxycholate-O-sulfate in PXB mice. It also diminished diurnal variation of plasma lithocholate-O-sulfate, glycolithocholate-O-sulfate, and taurolithocholate-O-sulfate in PXB mice under control conditions. Bile flow diversion did not affect the plasma concentration of bile acid-O-sulfates in monkeys and PXB mice treated with rifampicin. Plasma coproporphyrin I and III levels were constant in monkeys throughout the study, even with bile flow diversion. This study demonstrated that bile acid-O-sulfates are endogenous OATP1B biomarkers in monkeys and PXB mice. Enterohepatic circulation can affect the baseline levels of plasma bile acid-O-sulfates and modify the effect of OATP1B inhibition.

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.

Effect of probiotics on serum bile acids in patients with ulcerative colitis.

BACKGROUND/AIMS: Evaluation of bile acids (BA) is useful for assessing the changes of intestinal flora in patients with ulcerative colitis (UC). During enterohepatic circulation, the intestinal micro flora cause 7 alpha-dehydroxylation of cholic acid (CA) and chenodeoxycholic acid (CDCA), yielding deoxycholic acid(DCA) and lithocholic acid, respectively. The aim of the present study was to investigate the effects of probiotics in patients with UC by examining changes of the serum BA profile. METHODOLOGY: Twenty-seven patients were divided into the following 2 groups based on endoscopic findings: Fifteen patients with distal UC (dUC group) and 12 patients with pancolitis (pUC group). After treatment with mesalazine or salazosulfapyridine (5-ASA), all patients achieved remission. Then they were given 5-ASA plus the probiotic Clostridium butyricum Miyairi (3.0 g/day) for 4 weeks. RESULTS: After 4 weeks of probiotic treatment, %CDCA was significantly higher and %DCA was significantly lower in the pUC group than in the HV group. In contrast, the dUC group showed no significant differences of %CDCA or %DCA from the HV group after 4 weeks. CONCLUSIONS: Probiotic therapy restored intestinal flora involved in 7 alpha-dehydroxylation in the dUC group, but not in the pUC group.

High-dose ursodeoxycholic acid is associated with the development of colorectal neoplasia in patients with ulcerative colitis and primary sclerosing cholangitis.

OBJECTIVES: Some studies have suggested that ursodeoxycholic acid (UDCA) may have a chemopreventive effect on the development of colorectal neoplasia in patients with ulcerative colitis (UC) and primary sclerosing cholangitis (PSC). We examined the effects of high-dose (28-30 mg/kg/day) UDCA on the development of colorectal neoplasia in patients with UC and PSC. METHODS: Patients with UC and PSC enrolled in a prior, multicenter randomized placebo-controlled trial of high-dose UDCA were evaluated for the development of colorectal neoplasia. Patients with UC and PSC who received UDCA were compared with those who received placebo. We reviewed the pathology and colonoscopy reports for the development of low-grade or high-grade dysplasia or colorectal cancer. RESULTS: Fifty-six subjects were followed for a total of 235 patient years. Baseline characteristics (including duration of PSC and UC, medications, patient age, family history of colorectal cancer, and smoking status) were similar for both the groups. Patients who received high-dose UDCA had a significantly higher risk of developing colorectal neoplasia (dysplasia and cancer) during the study compared with those who received placebo (hazard ratio: 4.44, 95% confidence interval: 1.30-20.10, P=0.02). CONCLUSIONS: Long-term use of high-dose UDCA is associated with an increased risk of colorectal neoplasia in patients with UC and PSC.

Feed-forward regulation of bile acid detoxification by CYP3A4: studies in humanized transgenic mice.

Bile acids are potentially toxic end products of cholesterol metabolism and their concentrations must be tightly regulated. Homeostasis is maintained by both feed-forward regulation and feedback regulation. We used humanized transgenic mice incorporating 13 kb of the 5' regulatory flanking sequence of CYP3A4 linked to a lacZ reporter gene to explore the in vivo relationship between bile acids and physiological adaptive CYP3A gene regulation in acute cholestasis after bile duct ligation (BDL). Male transgenic mice were subjected to BDL or sham surgery prior to sacrifice on days 3, 6, and 10, and others were injected with intraperitoneal lithocholic acid (LCA) or vehicle alone. BDL resulted in marked hepatic activation of the CYP3A4/lacZ transgene in pericentral hepatocytes, with an 80-fold increase in transgene activation by day 10. Individual bile acids were quantified by liquid chromatography/mass spectrometry. Serum 6beta-hydroxylated bile acids were increased following BDL, confirming the physiological relevance of endogenous Cyp3a induction to bile acid detoxification. Although concentrations of conjugated primary bile acids increased after BDL, there was no increase in LCA, a putative PXR ligand, indicating that this cannot be the only endogenous bile acid mediating this protective response. Moreover, in LCA-treated animals, 5-bromo-4-chloro-3-indolyl-beta-d-galactopyranoside staining showed hepatic activation of the CYP3A4 transgene only on the liver capsular surface, and minimal parenchymal induction, despite significant liver injury. This study demonstrates that CYP3A up-regulation is a significant in vivo adaptive response to cholestasis. However, this up-regulation is not dependent on increases in circulating LCA and the role of other bile acids as regulatory molecules requires further exploration.

Concentration of unsulfated lithocholic acid in portal and systemic venous plasma: evidence that lithocholic acid does not down regulate the hepatic cholesterol 7 alpha-hydroxylase activity in gallstone patients.

It has been proposed that lithocholic acid may have a physiological role for the regulation of bile acid synthesis in humans. In this study, the portal concentration and hepatic uptake of unsulfated lithocholic acid was determined in 21 gallstone patients-untreated, cholestyramine-treated and chenodeoxycholic acid-treated-at cholecystectomy. Lithocholic acid was analyzed by a combined gas-liquid mass-fragmentographic technique. In most of the patients a liver biopsy was obtained for assay of the cholesterol 7 alpha-hydroxylase activity. The portal venous concentration of unsulfated lithocholic acid averaged 0.32 mumol/l in untreated patients, constituting about 4% of the total bile acids. The apparent hepatic uptake of lithocholic acid averaged 78%, being as high as that of cholic acid. No significant correlation was obtained between the portal venous concentration of unsulfated lithocholic acid and the hepatic cholesterol 7 alpha-hydroxylase activity. This study thus confirms an enterohepatic circulation of lithocholic acid in humans. No evidence was obtained that the portal venous inflow of small amounts of lithocholic acid to the liver is of regulatory importance for the cholesterol 7 alpha-hydroxylase activity.

Diagnostic effectiveness of serum bile acids in liver diseases as evaluated by multivariate statistical methods.

The aims of this study were to determine the diagnostic effectiveness of fasting and postprandial serum bile acid determinations in liver diseases, and to compare results with those of conventional liver function tests. In 322 patients with biopsy-proved liver disease and 93 healthy subjects, fasting and postprandial (2 hr) serum levels of cholic, chenodeoxycholic, and lithocholic acid conjugates and conventional liver function tests were evaluated. Data were subjected to variance and discriminant and factor analyses. Fasting serum bile acids were higher in patients when compared to controls and were significantly higher in severe than in mild liver diseases. Determination of cholic plus lithocholic acid provided the highest discrimination capacity. The percent of correct allocation was 75.4% for conventional liver function tests, 70.1% for fasting serum bile acids and increased to 79.6% when liver function tests plus serum bile acids were considered. Postprandial percentages were always lower than fasting. Factor analysis identified two factors possibly related to cytolysis and protein synthesis. The serum bile acid concentrations highly correlated with both factors. We conclude that serum bile acid determinations increase the diagnostic and discriminant capacities of liver function tests and are more sensitive and discriminant when obtained in fasting than postprandially.

Ursodeoxycholic acid: a safe and effective agent for dissolving cholesterol gallstones.

Ursodeoxycholic acid, 250 to 300, 500 to 600, or 900 to 1000 mg/d, was given orally for 6 to 38 months to 53 patients with cholesterol gallstones and functioning gallbladders. Forty-two patients had greater than 50% reduction in gallstone volume, number, or both, without apparent dose dependence and 27 of these patients had complete gallstone dissolution. Results of laboratory studies including liver function tests were not affected adversely and biliary lithocholic acid concentration did not increase during therapy. Most biliary symptoms seemed to disappear within 3 months and no patient developed diarrhea. Large diameter and increased number of gallstones were found to hinder dissolution. The percentage of biliary ursodeoxycholic acid increased with increasing dose and reached a maximum of 50% to 60% of total bile acids at a dose of about 10 to 12 mg/kg body weight. d. Biliary lithogenic index was reduced significantly during treatment with ursodeoxycholic acid, 500 to 600 and 900 to 1000 mg/d. Thus, ursodeoxycholic acid appears to be a safe and effective alternative to surgery in selected patients with gallstones.

[Clinical evaluation of serum bile acids as a new liver function test (author's transl)]. / Die klinische Bewertung der Serumgallensäuren als neuer Leberfunktionstest.

In a randomized patient material, with various histologically verified hepatobiliary diseases, the serum levels of Cholyl glycine (CG) and Sulfolithocholyl glycine (SLCG) were compared with each other. SLCG levels are a more sensitive parameter and permit a more significant differentiation between fatty and normal livers and between cases with and without portal hypertension in liver cirrhosis. There were poor correlations between the hitherto routinely performed laboratory tests and the SLCG levels, but good correlations between SLCG and defined parenchymal liver diseases. the publication ends with the presentation of a newly developed SLCG-stimulation test, which provides a staging of parenchymal liver diseases without unnecessary requirements of time and material and with minimal stress to the patients.

Hepatotoxic effect of bile acids in inflammatory bowel disease.

Lithocholate, a secondary bile acid, is hepatotoxic in many animal species including nonhuman primates. The induced histologic changes resemble those observed in patients with hepatic damage associated with inflammatory bowel disease. Accordingly, we have examined the hypothesis that lithocholate is of etiologic importance in causing this association by measuring serum and biliary lithocholates in inflammatory bowel disease patients with and without liver disease. Serum and biliary lithocholates and isolithocholates were normal in all patients. Because defective sulfation in the nonhuman primate which allows lithocholate to accumulate in the enterohepatic circulation is thought to be responsible for inducing liver damage and because secondary bile acids are reduced after colectomy and in established liver disease, we examined thae capacity of all patients to sulfate labeled lithocholate. Effective sulfation of lithocholate was demstrated in all groups. Despite the hepatotoxic effects observed in nonhuman primates, we have found no evidence so far to implicate lithocholate as an etiologic factor in inflammatory bowel disease and hepatic dysfunction nor have we detected other potentially hepatotoxic bile acids in these patients.

Portal vein bile acids in patients with severe inflammatory bowel disease.

The incidence of several forms of liver disease associated with inflammatory bowel disease has been putatively ascribed to a toxic effect on the liver of portal vein bile acids abnormal in type or amount. To examine this possibility, total bile acid concentrations (sulphated and non-sulphated) were measured by gas-liquid chromatography in inferior mesentric vein serum of 19 patients undergoing colectomy for severe inflammatory bowel disease (IBD). Similar determinations were obtained on a control group of eight patients requiring colectomy for other non-inflammatory conditions. Mean values for mesenteric vein serum bile acid concentrations (muM/1) were 19.6+/-1.8 in controls and 16.3+/-2.0 in IBD. The mean sulphated bile acid fraction did not exceed 10% of total, although there was considerable variability (up to 40% of total). Lithocholic acid levels (entirely sulphated in all patients) were low. Although the IBD group showed a more than two-fold increase in mean lithocholate concentration (0.54+/-0.15 muM/1) over controls (0.21 +/- muM/1), this difference was not statistically significant. No significant intra-group difference was noted in the non-sulphated and sulphated fractions for cholic, chenodeoxycholic, and deoxycholic acid species, respectively. No unidentified or unusual bile acids were observed. There was no correlation between bile acid measurements and liver histology. These findings fail to support the hypothesis that liver disease often found in association with severe inflammatory bowel disease represents a form of bile acid toxicity. The invariable finding of total sulphation of the lithocholic acid fraction even in the presence of severe mucosal disease was unexpected.

[Clinical significance of serum bile acid radioimmunoassay in hepatobiliary diseases--with special reference to the CG/SLCG ratio (author's transl)].

Both serum cholylglycine (CG) and sulfolithocholylglycine (SLCG) levels were radioimmunoassayed by PEG method in 209 samples (204 hepatobiliary diseases, 5 normal controls). 1) The results revealed that serum bile acid levels were excellent indicators for hepatic dysfunction in comparison with the conventional liver function tests. 2) Means of 19.4 +/- 9.3 microgram/dl for CG and 21.7 +/- 6.7 microgram/dl for SLCG were obtained in controls. Most hepatobiliary diseases demonstrated abnormally high bile acid levels, with extremely high CG values in conditions with bile stasis. 3) To differentiate various hepatobiliary diseases more clearly, the ratio of the primary and secondary bile acids (CG/SLCG ratio) was introduced (1.0 +/- 0.6 for controls). In cases of bile stasis, CG/SLCG ratios ranged from 7.8 +/- 4.8 for intrahepatic cholestasis to 34.8 +/- 27.6 for congenital biliary atresia, while other hepatic disorders demonstrated relatively low values. We conclude that the CG/SLCG ratio is a useful index for cholestasis. Diagnosis of the congenital biliary atresia could be possible.

[The clinical significance of radioimmunologically determined serum bile acids as a new liver function test and the development of a new intravenous sulfolithoglycocholic acid (SLGC) stimulation test]. / Die klinische Bedeutung radioimmunologisch bestimmter Serumgallensäuren als neuer Leberfunktionstest und die Entwicklung eines neuen intravenösen Sulfolithoglykocholsäure-(SLCG-) Stimulationstests.

Cholylglycin (CG-) and SLCG levels were measured in patients with various biopsy-confirmed liver and bile disease. SLCG values were found to be more sensitive, and to distinguish clearly between steatosis hepatis and normals, as well as between cirrhosis hepatis, with and without, portal hypertension. Correlations between the common liver tests and the SLCG levels were poor, but a clear distinction was possible between the various histologically defined liver diseases. The paper concludes with a description of a new method of stimulating the SLCG values, intravenously. Using this method, it is possible to keep consumption of material and time and incommodities inflicted to the patient, as low as possible. Nevertheless staging of parenchymatous liver diseases, is feasible.

[Plasma bile acids fractionnation by gas-liquid chromatography : application to hepatocellular deficiency investigation (author's transl)]. / Fractionnement par chromatographie gazeuse des acides biliaires plasmatiques. Application à l'étude d'atteintes cellulaires hépatiques.

The level of the four major bile acids was measured in the plasma using gas liquid chromatography. The enhancement of the level of the primary bile acids was well known during bile duct obstruction. In the case of hepatic diseases, the chenodesoxycholiccholic acid concentration ratio (CDC/C) was equal or lower than unity when cholestasis occurred rather than hepatic deficiency. When hepatic deficiency developed, the ratio CDC/C was higher than unity. Plasma bile acid fractionnation exhibits also a prognostic value. When the ratio CDC/C is very high, it is significant of progressive hepatic deficiency. A high level of lithocholic acid is also a sign of unfavourable prognosis.

Cholestatic liver disease associated with diphenylhydantoin therapy. Possible pathogenic importance of altered bile salt metabolism.

A ten-year-old boy persented with a prolonged cholestatic liver disease 5 weeks after starting diphenylhydantoin therapy. The initial phase of his illness was characterized by hepatocellular damage with swollen liver cells and centrilobular cholestasis. Severe hyperlipoproteinemia with eruptive xanthomata developed within 3 weeks of his initial jaundice. The second phase of his illness was characterized by portal tract inflammation with bile ductular proliferation and chronic cholestasis gradually resolving over a period of 15 months. It is postulated that diphenylhydantoin sensitivity produced swollen hepatocytes with hypertrophy of the smooth endoplasmic reticulum, reducing hepatic sinusoidal blood flow and the clearance of secondary bile salts. A fall in clearance of lipoproteins, including the cholesterol precursor of primary bile acid synthesis, may have been responsible for a reduction in serum bile acid concentration. High levels of serum lithocholic acid, largely unsulfated presumably due to decreased hepatic uptake, may have produced the prolonged second phase of this illness when histological changes resembled that seen in experimental animals following lithocholic acid administration.