Serum 7-alpha-hydroxy-4-cholesten-3-one as a marker for bile acid loss in children.

OBJECTIVE: To establish age-related reference values for 7-alpha-hydroxy-4-cholesten-3-one (C4) in a pediatric population and to investigate bile acid malabsorption in children with short bowel syndrome (SBS). STUDY DESIGN: Serum was obtained between 8:00 a.m. and 11:00 a.m. from 100 healthy children (52% males, 9 months to 18 years of age) after 10 hours of fasting. Pediatric patients with SBS served as disease controls (n = 12). Following solid-phase extraction and purification, C4 was determined by high-performance liquid chromatography using a ultraviolet detector at a wavelength of 241 nm. The upper limit of normal for C4 concentrations was defined as the mean plus 2 SD of the log-normal distribution. RESULTS: The mean concentration and SD of C4 in healthy children was 22.8 ± 15.8 ng/mL with no relation to age or sex and an upper limit of normal of 66.5 ng/mL. Normal C4 values were found in 97 of 100 healthy children, and all 12 patients with SBS had C4 concentrations above 100 ng/mL (mean 299.6 ± 167.8 ng/mL; range 105.7-562.1 ng/mL, P < .0001 compared with controls). CONCLUSIONS: The determined upper limit of normal for C4 concentration in healthy children corresponds to previously published levels in healthy adults and is independent of age and sex. The consistently elevated C4 concentrations in our patients with SBS confirm the reliability of this noninvasive, nonisotopic method to assess bile acid malabsorption in children.

Farnesoid X receptor agonist tropifexor attenuates cholestasis in a randomised trial in patients with primary biliary cholangitis.

Background & Aims: The safety, tolerability, and efficacy of the non-bile acid farnesoid X receptor agonist tropifexor were evaluated in a phase II, double-blind, placebo-controlled study as potential second-line therapy for patients with primary biliary cholangitis (PBC) with an inadequate ursodeoxycholic acid response. Methods: Patients were randomised (2:1) to receive tropifexor (30, 60, 90, or 150 µg) or matched placebo orally once daily for 28 days, with follow-up on Days 56 and 84. Primary endpoints were safety and tolerability of tropifexor and reduction in levels of γ-glutamyl transferase (GGT) and other liver biomarkers. Other objectives included patient-reported outcome measures using the PBC-40 quality-of-life (QoL) and visual analogue scale scores and tropifexor pharmacokinetics. Results: Of 61 enrolled patients, 11, 9, 12, and 8 received 30-, 60-, 90-, and 150-µg tropifexor, respectively, and 21 received placebo; 3 patients discontinued treatment because of adverse events (AEs) in the 150-µg tropifexor group. Pruritus was the most frequent AE in the study (52.5% [tropifexor] vs. 28.6% [placebo]), with most events of mild to moderate severity. Decreases seen in LDL-, HDL-, and total-cholesterol levels at 60-, 90-, and 150 µg doses stabilised after treatment discontinuation. By Day 28, tropifexor caused 26-72% reduction in GGT from baseline at 30- to 150-µg doses (p <0.001 at 60-, 90-, and 150-µg tropifexor vs. placebo). Day 28 QoL scores were comparable between the placebo and tropifexor groups. A dose-dependent increase in plasma tropifexor concentration was observed, with 5- to 5.55-fold increases in AUC0-8h and Cmax between 30- and 150-µg doses. Conclusions: Tropifexor showed improvement in cholestatic markers relative to placebo, predictable pharmacokinetics, and an acceptable safety-tolerability profile, thereby supporting its potential further clinical development for PBC. Lay summary: The bile acid ursodeoxycholic acid (UDCA) is the standard-of-care therapy for primary biliary cholangitis (PBC), but approximately 40% of patients have an inadequate response to this therapy. Tropifexor is a highly potent non-bile acid agonist of the farnesoid X receptor that is under clinical development for various chronic liver diseases. In the current study, in patients with an inadequate response to UDCA, tropifexor was found to be safe and well tolerated, with improved levels of markers of bile duct injury at very low (microgram) doses. Itch of mild to moderate severity was observed in all groups including placebo but was more frequent at the highest tropifexor dose. Clinical Trials Registration: This study is registered at ClinicalTrials.gov (NCT02516605).

NASH-related increases in plasma bile acid levels depend on insulin resistance.

BACKGROUND & AIMS: Plasma bile acids (BAs) have been extensively studied as pathophysiological actors in non-alcoholic steatohepatitis (NASH). However, results from clinical studies are often complicated by the association of NASH with type 2 diabetes (T2D), obesity, and insulin resistance (IR). Here, we sought to dissect the relationship between NASH, T2D, and plasma BA levels in a large patient cohort. METHODS: Four groups of patients from the Biological Atlas of Severe Obesity (ABOS) cohort (Clinical Trials number NCT01129297) were included based on the presence or absence of histologically evaluated NASH with or without coincident T2D. Patients were matched for BMI, homeostatic model assessment 2 (HOMA2)-assessed IR, glycated haemoglobin, age, and gender. To study the effect of IR and BMI on the association of plasma BA and NASH, patients from the HEPADIP study were included. In both cohorts, fasting plasma BA concentrations were measured. RESULTS: Plasma BA concentrations were higher in NASH compared with No-NASH patients both in T2D and NoT2D patients from the ABOS cohort. As we previously reported that plasma BA levels were unaltered in NASH patients of the HEPADIP cohort, we assessed the impact of BMI and IR on the association of NASH and BA on the combined BA datasets. Our results revealed that NASH-associated increases in plasma total cholic acid (CA) concentrations depend on the degree of HOMA2-assessed systemic IR, but not on ß-cell function nor on BMI. CONCLUSIONS: Plasma BA concentrations are elevated only in those NASH patients exhibiting pronounced IR. LAY SUMMARY: Non-alcoholic steatohepatitis (NASH) is a progressive liver disease that frequently occurs in patients with obesity and type 2 diabetes. Reliable markers for the diagnosis of NASH are needed. Plasma bile acids have been proposed as NASH biomarkers. Herein, we found that plasma bile acids are only elevated in patients with NASH when significant insulin resistance is present, limiting their utility as NASH markers.