Serum bile acids as a prognostic biomarker in biliary atresia following Kasai portoenterostomy

Efficacy and safety of odevixibat in patients with Alagille syndrome (ASSERT): a phase 3, double-blind, randomised, placebo-controlled trial

BACKGROUND

In patients with Alagille syndrome, cholestasis-associated clinical features can include high serum bile acids and severe pruritus that can necessitate liver transplantation. We aimed to evaluate the efficacy and safety of the ileal bile acid transporter inhibitor odevixibat versus placebo in patients with Alagille syndrome.

METHODS

The ASSERT study was a phase 3, double-blind, randomised, placebo-controlled trial that enrolled patients at 21 medical centres or hospitals in ten countries (Belgium, France, Germany, Italy, Malaysia, the Netherlands, Poland, Türkiye, the UK, and the USA). Eligible patients had a genetically confirmed diagnosis of Alagille syndrome, a history of significant pruritus, and elevated serum bile acids. Patients were randomly assigned (2:1) to receive oral odevixibat 120 μg/kg per day or placebo for 24 weeks (in a block size of six and stratified by age: <10 years and ≥10 years to <18 years) via a web-based system. Patients, clinicians, study staff, and people analysing the data were masked to treatment allocation. The primary efficacy endpoint was change in caregiver-reported scratching score (on the PRUCISION instrument; range 0-4) from baseline to weeks 21-24. The prespecified key secondary efficacy endpoint was change in serum bile acid concentration from baseline to the average of weeks 20 and 24. Outcomes were analysed in patients who received at least one dose of study drug (the full analysis set for efficacy outcomes and the safety analysis set for safety outcomes). This trial is registered on ClinicalTrials.gov (NCT04674761) and EudraCT (2020-004011-28), and is completed.

FINDINGS

Between Feb 26, 2021, and Sept 9, 2022, 52 patients were randomly assigned to receive odevixibat (n=35) or placebo (n=17), all of whom were included in the analysis sets. The median age was 5·5 years (IQR 3·2 to 8·9). 27 (52%) of 52 patients were male and 25 (48%) were female. The mean scratching score was elevated at baseline in both groups (2·8 [SD 0·5] for odevixibat vs 3·0 [0·6] for placebo). Mean scratching scores at weeks 21-24 were 1·1 (0·9) for odevixibat and 2·2 (1·0) for placebo, representing a least-squares (LS) mean change of -1·7 (95% CI -2·0 to -1·3) for odevixibat and -0·8 (-1·3 to -0·3) for placebo, which was significantly greater for odevixibat than for placebo (difference in LS mean change from baseline -0·9 [95% CI -1·4 to -0·3]; p=0·0024). Odevixibat also resulted in significantly greater reductions in mean serum bile acids from baseline versus placebo (237 μmol/L [SD 115] with odevixibat vs 246 μmol/L [121] with placebo) to the average of weeks 20 and 24 (149 μmol/L [102] vs 271 μmol/L [167]; LS mean change -90 μmol/L [95% CI -133 to -48] with odevixibat vs 22 μmol/L [-35 to 80] with placebo; difference in LS mean change -113 μmol/L [95% CI -179 to -47]; p=0·0012). The most common treatment-emergent adverse events were diarrhoea (ten [29%] of 35 patients in the odevixibat group vs one [6%] of 17 in the placebo group) and pyrexia (eight [23%] vs four [24%]). Seven patients had serious treatment-emergent adverse events during the treatment period: five (14%) in the odevixibat group and two (12%) in the placebo group. No patients discontinued treatment and there were no deaths.

INTERPRETATION

Odevixibat could be an efficacious non-surgical intervention to improve pruritus, reduce serum bile acids, and enhance the standard of care in patients with Alagille syndrome. Longer-term safety and efficacy data of odevixibat in this population are awaited from the ongoing, open-label ASSERT-EXT study.

FUNDING

Albireo Pharma, an Ipsen company.

Progress in Biomarkers Related to Biliary Atresia

Biliary atresia (BA) is a congenital cholestatic disease that can seriously damage children's liver function. It is one of the main reasons for liver transplantation in children. Early diagnosis of BA is crucial to the prognosis of patients, but there is still a lack of reliable non-invasive diagnostic methods. Additionally, as some children are in urgent need of liver transplantation, evaluating the stage of liver fibrosis and postoperative native liver survival in children with BA using a straightforward, efficient, and less traumatic method is a major focus of doctors. In recent years, an increasing number of BA-related biomarkers have been identified and have shown great potential in the following three aspects of clinical practice: diagnosis, evaluation of the stage of liver fibrosis, and prediction of native liver survival. This review focuses on the pathophysiological function and clinical application of three novel BA-related biomarkers, namely MMP-7, FGF-19, and M2BPGi. Furthermore, progress in well-known biomarkers of BA such as gamma-glutamyltransferase, circulating cytokines, and other potential biomarkers is discussed, aiming to provide a reference for clinical practice.

The magnetic resonance imaging and age-adjusted matrix metalloproteinase-7 assist the diagnosis of biliary atresia

BACKGROUND

We investigated the utilities of the liver-to-psoas apparent diffusion coefficient ratios (LTPAR) yielded by diffusion-weighted magnetic resonance imaging (DWMRI) and the age-adjusted serum matrix metalloproteinase-7 (MMP-7) for the diagnosis of biliary atresia (BA) in cholestatic infants.

METHODS

In total, 170 cholestatic infants were recruited, of whom 50 (29.41%) were diagnosed with BA after cholestatic workups. The LTPAR and MMP7 levels were assessed.

RESULTS

The LTPAR was significantly lower in BA infants, and the age-adjusted MMP7 ratio was significantly higher, compared to other cholestatic infants (both p < 0.001). Receiver operating characteristic curve analysis yielded a cutoff > 0.1 ng/mL.day for the age-adjusted MMP-7 ratio, and an LTPAR < 1.01 for the optimal prediction of BA (both p < 0.001). Univariate logistic regression analysis revealed that both an age-adjusted MMP-7 ratio > 0.1 ng/mL.day and an LTPAR < 1.01 were significant predictors of BA among cholestatic infants (odds ratio = 30.98 and 13.28; p < 0.001 and < 0.001, respectively). The significance of the age-adjusted MMP-7 ratio and the LTPAR persisted on multivariate logistic regression analysis after adjusting for sex and the serum gamma-glutamyl transferase level (p < 0.001 and < 0.001, respectively). The negative predictive values (NPVs) for BA were 91.49% and 94.17%, respectively, for the LTPAR and age-adjusted MMP-7 ratio.

CONCLUSION

The age-adjusted MMP-7 ratio and the LTPAR are both significant non-invasive predictors of BA. The consideration of both serum and imaging parameters may enhance BA diagnostic performance in cholestatic infants.

Bile acid profiles in adult patients with biliary atresia who achieve native liver survival after portoenterostomy

Bile acids have received increasing attention as a marker of the long-term prognosis and a potential therapeutic target in patients with biliary atresia, which is a progressive disease of the hepatobiliary system. A detailed analysis of serum and urinary bile acid compositions was conducted to assess the characteristics of bile acid profiles and the correlation between bile acid profiles and liver fibrosis markers in adult patients with biliary atresia who achieved bilirubin normalization. Serum total bile acids and glucuronide-conjugated (glyco- and tauro-) cholic acids (GCA and TCA) and chenodeoxycholic acids (GCDCA and TCDCA) were significantly higher in patients with biliary atresia than in healthy controls, whereas unconjugated CA and CDCA showed no significant difference. There were no significant differences in CA to CDCA ratios and glycine-to-taurine-conjugated ratios. Urinary glycocholic acid 3-sulfate (GCA-3S) was significantly higher in patients with biliary atresia. Serum GCDCA showed a strong positive correlation with Mac-2 binding protein glycosylation isomer (M2BPGi). These results demonstrate that bile acid congestion persists into adulthood in patients with biliary atresia, even after cholestasis has completely improved after Kasai portoenterostomy. These fundamental data on bile acid profiles also suggest the potential value of investigating bile acid profiles in patients with biliary atresia.

Deep learning quantification reveals a fundamental prognostic role for ductular reaction in biliary atresia

BACKGROUND

We aimed to quantify ductular reaction (DR) in biliary atresia using a neural network in relation to underlying pathophysiology and prognosis.

METHODS

Image-processing neural network model was applied to 259 cytokeratin-7-stained native liver biopsies of patients with biliary atresia and 43 controls. The model quantified total proportional DR (DR%) composed of portal biliary epithelium (BE%) and parenchymal intermediate hepatocytes (PIH%). The results were related to clinical data, Sirius Red-quantified liver fibrosis, serum biomarkers, and bile acids.

RESULTS

In total, 2 biliary atresia biopsies were obtained preoperatively, 116 at Kasai portoenterostomy (KPE) and 141 during post-KPE follow-up. DR% (8.3% vs. 5.9%, p=0.045) and PIH% (1.3% vs. 0.6%, p=0.004) were increased at KPE in patients remaining cholestatic postoperatively. After KPE, patients with subsequent liver transplantation or death showed an increase in DR% (7.9%-9.9%, p = 0.04) and PIH% (1.6%-2.4%, p = 0.009), whereas patients with native liver survival (NLS) showed decreasing BE% (5.5%-3.0%, p = 0.03) and persistently low PIH% (0.9% vs. 1.3%, p = 0.11). In Cox regression, high DR predicted inferior NLS both at KPE [DR% (HR = 1.05, p = 0.01), BE% (HR = 1.05, p = 0.03), and PIH% (HR = 1.13, p = 0.005)] and during follow-up [DR% (HR = 1.08, p<0.0001), BE% (HR = 1.58, p = 0.001), and PIH% (HR = 1.04, p = 0.008)]. DR% correlated with Sirius red-quantified liver fibrosis at KPE (R = 0.47, p<0.0001) and follow-up (R = 0.27, p = 0.004). A close association between DR% and serum bile acids was observed at follow-up (R = 0.61, p<0.001). Liver fibrosis was not prognostic for NLS at KPE (HR = 1.00, p = 0.96) or follow-up (HR = 1.01, p = 0.29).

CONCLUSIONS

DR predicted NLS in different disease stages before transplantation while associating with serum bile acids after KPE.

Early bile drainage improves native liver survival in biliary atresia without cholangitis

Objectives

To explore the outcomes and related factors in children without cholangitis after Kasai portoenterostomy (KPE).

Methods

We retrospectively analyzed the data of infants with type III BA who underwent KPE from June 2016 to December 2021. We compared and analyzed the difference in native liver survival (NLS) rates in different types of cholangitis. We also investigated the relationship between the absence of cholangitis and the effect of early bile drainage (EBD) as well as the related factors affecting EBD efficacy.

Results

A total of 145 children were included in this study. Among these children, 82 (56.6%, 82/145) had cholangitis, including 40 (48.8%, 40/82) with early cholangitis and 33 (40.2%, 33/82) with recurrent cholangitis. The median follow-up period was 29 months (range, 2-75 months). The NLS rates were 67.6%, 51.7%, 45.5% and 43.4% at 6 months, 1 year, 2 years and 5 years following KPE, while the NLS rates for infants without cholangitis after KPE were 68.3%, 50.8%, 46.0% and 46.0%, respectively. Higher gamma-glutamyl transferase (γ- GT) and total bile acid (TBA) before KPE were risk factors for cholangitis (P < 0.05). The NLS rate in recurrent cholangitis was significantly lower than that in occasional cholangitis (P < 0.01). Compared with the EBD-poor group, the NLS rate in the EBD-good group of infants was significantly increased (P < 0.001). EBD was significantly correlated with the occurrence and frequency of cholangitis (P < 0.05).

Conclusions

Recurrent cholangitis was an important factor affecting NLS. For children without cholangitis after KPE, early bile drainage was better, and the NLS was longer.

Elevated bile acids are associated with left ventricular structural changes in biliary atresia

BACKGROUND

In children with biliary atresia (BA), pathologic structural changes within the heart, which define cirrhotic cardiomyopathy, are associated with adverse perioperative outcomes. Despite their clinical relevance, little is known about the pathogenesis and triggers of pathologic remodeling. Bile acid excess causes cardiomyopathy in experimental cirrhosis, but its role in BA is poorly understood.

METHODS

Echocardiographic parameters of left ventricular (LV) geometry [LV mass (LVM), LVM indexed to height, left atrial volume indexed to BSA (LAVI), and LV internal diameter (LVID)] were correlated with circulating serum bile acid concentrations in 40 children (52% female) with BA listed for transplantation. A receiver-operating characteristic curve was generated to determine optimal threshold values of bile acids to detect pathologic changes in LV geometry using Youden index. Paraffin-embedded human heart tissue was separately analyzed by immunohistochemistry for the presence of bile acid-sensing Takeda G-protein-coupled membrane receptor type 5.

RESULTS

In the cohort, 52% (21/40) of children had abnormal LV geometry; the optimal bile acid concentration to detect this abnormality with 70% sensitivity and 64% specificity was 152 µmol/L (C-statistics=0.68). Children with bile acid concentrations >152 µmol/L had ∼8-fold increased odds of detecting abnormalities in LVM, LVM index, left atrial volume index, and LV internal diameter. Serum bile acids positively correlated with LVM, LVM index, and LV internal diameter. Separately, Takeda G-protein-coupled membrane receptor type 5 protein was detected in myocardial vasculature and cardiomyocytes on immunohistochemistry.

CONCLUSION

This association highlights the unique role of bile acids as one of the targetable potential triggers for myocardial structural changes in BA.