Dynamic Risk Prediction of Response to Ursodeoxycholic Acid Among Patients with Primary Biliary Cholangitis in the USA

Primary biliary cholangitis: Personalizing second-line therapies

Primary biliary cholangitis (PBC) is an enigmatic, autoimmune disease targeting the small intralobular bile ducts resulting in cholestasis and potentially progression to biliary cirrhosis. Primarily affecting middle-aged women, the diagnosis of PBC is typically straightforward, with most patients presenting with cholestatic liver tests and the highly specific antimitochondrial antibody. For decades, the foundational treatment of PBC has been ursodeoxycholic acid, which delays disease progression in most patients but has no impact on PBC symptoms. Large cohort studies of patients with PBC have established the benefit of maximizing the reduction in serum alkaline phosphatase levels with ursodeoxycholic acid and the need to add second-line agents in patients who do not achieve an adequate response. Advances in the understanding of bile acid physiology have led to the development of new agents that improve cholestasis in patients with PBC and are predicted to reduce the risk of disease progression. Obeticholic acid, the first second-line therapy to be approved for PBC, significantly improves liver biochemistries and has been associated with improved long-term clinical outcomes but is limited by its propensity to induce pruritus. Elafibranor and seladelpar are peroxisome proliferator-activated receptor agonists recently approved for use in patients with PBC, whereas bezafibrate and fenofibrate are available as off-label therapies. They also have shown biochemical improvements among patients with an inadequate response to ursodeoxycholic acid but may improve symptoms of pruritus. Herein, we review the patient features to consider when deciding whether a second-line agent is indicated and which agent to consider for a truly personalized approach to PBC patient care.

The treatment of primary biliary cholangitis: from shadow to light

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic disease characterized by the destruction of the small intrahepatic bile ducts, which can progress to liver cirrhosis. The gold standard in the treatment of PBC is ursodeoxycholic acid (UDCA), which is indicated in all patients with PBC because it improves not only biochemical parameters but also patients' survival. An important milestone in the identification of patients at risk is the assessment of biochemical response to UDCA. Patients who respond to treatment have a lower incidence of hepatic events and better prognosis than patients who do not. Several scoring systems can be used to assess the response and identify non-responders who will benefit from second-line treatment. Obeticholic acid (OCA) is currently the only approved second-line treatment for PBC, which is effective for non-responders to UDCA therapy or patients, who have not tolerated UDCA therapy. However, OCA is contraindicated in advanced liver cirrhosis and portal hypertension. Moreover, pruritus may be a limiting factor for the administration of OCA. Fibrates have shown promising data supporting their use in non-responders to UDCA because they improve the biochemical parameters and elastographic findings and have possible antipruritic effects. Therefore, the idea of a triple treatment seems interesting. Clinical research is focusing on several other groups of drugs: peroxisome proliferator-activated receptor (PPAR) δ- and α/δ agonists, non-steroidal farnesoid X receptor agonists, fibroblast growth factor 19 modulators, and inhibitors of nicotinamide adenine dinucleotide phosphate oxidase 1 and 4.

A new and simple score to predict adequate and deep response to ursodeoxycholic acid in patients with primary biliary cholangitis: the ALP-A score

BACKGROUND

Ursodeoxycholic acid (UDCA) is the standard treatment for primary biliary cholangitis (PBC), but a significant proportion of patients do not respond adequately, leading to increased risk of adverse outcomes. This study aims to develop a new and straightforward predictive score to identify PBC patients likely to achieve a complete response to UDCA.

METHODS

A logistic regression analysis was conducted using a derivation cohort of PBC patients to identify pre-treatment variables associated with response to UDCA. This analysis led to the development of the ALP-A score, calculated as: Age at diagnosis divided by (alkaline phosphatase at diagnosis/upper limit of normal). ALP-A score accuracy was evaluated using the area under the ROC curve, validated with a large external cohort from Brazil. Additionally, the correlation between the ALP-A score and the previously validated UDCA response score (URS) was assessed.

RESULTS

ALP-A score had good predictive power for adequate (AUC 0.794; 95% CI, 0.737-0.852) and deep (0.76; 95% CI, 0.69-0.83) UDCA response at 1 year of treatment. A cutoff score of 17 and 23 points was determined to be the optimal threshold for distinguishing adequate and deep responders, respectively, from non-responders. ALP-A score demonstrated a sensitivity of 73%, specificity of 71%, positive predictive value of 65%, negative predictive value of 78%, and overall accuracy of 72% for biochemical response. The URS displayed similar discriminative ability (AUC 0.798; 95% CI, 0.741-0.855).

CONCLUSION

ALP-A score performs comparably to URS but offers the great advantage of simplicity for routine clinical use. It serves as a valuable tool to identify PBC patients less likely to respond to UDCA treatment, facilitating early consideration of alternative therapeutic approaches.

Hirsutella sinensis mycelium polysaccharides attenuate the TGF-β1-induced epithelial-mesenchymal transition in human intrahepatic bile duct epithelial cells

Hirsutella sinensis is the anamorph of Ophiocordyceps sinensis, and its mycelia has been used to effectively treat a variety of hepatobiliary diseases in clinical practice. In the present study, we performed a systematic study on the composition and structure of its polysaccharides, and then employed a TGF-β1-induced human intrahepatic bile duct epithelial cell-epithelial-mesenchymal transition (HIBEC-EMT) model to investigate their effects on treating primary biliary cholangitis (PBC) based on hepatic bile duct fibrosis. Four polysaccharide fractions were obtained from H. sinensis mycelia by hot-water extraction, DEAE-cellulose column and gradient ethanol precipitation separation. HSWP-1a was an α-(1,4)-D-glucan; HSWP-1b and HSWP-1d mainly consisted of mannoglucans with a backbone composed of 1,4-linked α-D-Glcp and 1,4,6-linked α-D-Manp residues branched at O-6 of the 1,4-linked α-D-Glcp with a 1-linked α-D-Glcp as a side chain; and HSWP-1c mainly contained galactomannoglucans. These polysaccharide fractions protected HIBECs from a TGF-β1-induced EMT, according to HIBEC morphological changes, cell viability, decreased E-cadherin and ZO-1 expression, and increased vimentin and collagen I expression. Furthermore, the effects of the polysaccharides might be mediated by inhibiting the activation of the TGF-β/Smad signaling pathway, which attenuated hepatic bile duct fibrosis and potential PBC effects.

Optimizing therapy in primary biliary cholangitis: Alkaline phosphatase at six months identifies one-year non-responders and predicts survival

BACKGROUND AND AIMS

Patients with primary biliary cholangitis (PBC) and insufficient response to ursodeoxycholic acid (UDCA), currently assessed after 1 year, are candidates for second-line therapy. The aims of this study are to assess biochemical response pattern and determine the utility of alkaline phosphatase (ALP) at six months as a predictor of insufficient response.

METHODS

UDCA-treated patients in the GLOBAL PBC database with available liver biochemistries at one year were included. POISE criteria were used to assess response to treatment, defined as ALP <1.67 × upper limit of normal (ULN) and normal total bilirubin at one year. Various thresholds of ALP at six months were evaluated to predict insufficient response based on negative predictive value (NPV) and that with nearest to 90% NPV was selected.

RESULTS

For the study, 1362 patients were included, 1232 (90.5%) female, mean age of 54 years. The POISE criteria were met by 56.4% (n = 768) of patients at one year. The median ALP (IQR) of those who met POISE criteria compared to those who did not was 1.05 × ULN (0.82-1.33) vs. 2.37 × ULN (1.72-3.69) at six months (p < .001). Of 235 patients with serum ALP >1.9 × ULN at six months, 89% did not achieve POISE criteria (NPV) after one year of UDCA. Of those with insufficient response by POISE criteria at one year, 210 (67%) had an ALP >1.9 × ULN at six months and thus would have been identified early.

CONCLUSIONS

We can identify patients for second-line therapy at six months using an ALP threshold of 1.9 × ULN, given that approximately 90% of these patients are non-responders according to POISE criteria.

Incomplete response to ursodeoxycholic acid in primary biliary cholangitis: criteria, epidemiology, and possible mechanisms

INTRODUCTION

As a common autoimmune disease with the characteristic of early complication, primary biliary cholangitis (PBC) leads to an increasing number of mortalities among people with end-stage liver disease (ESLD) waiting for liver transplantation. Ursodeoxycholic acid (UDCA) is the only approved first-line medicine for PBC, and a good response to treatment could acquire an ideal prognosis. Patients with poor UDCA response usually have more adverse outcomes and worse survival, therefore, the management of this group become a major consideration.

AREAS COVERED

Due to the complexity of race and environment for PBC, different criteria for UDCA response exhibit various predictive performances. Factors affecting UDCA response conditions include gender, age, ethnicity, serum indicators, auto-antibodies, and autoimmune comorbidities, while no agreement has been reached. In this review, we mainly focus on cellular senescence, immune-mediated damage, and vitamin D deficiency as possible mechanisms for UDCA non-responders.

EXPERT OPINION

The pathogenesis of PBC has yet to be clarified. Immunology-related mechanisms and therapy targets ought to be the main effort made for further study. Irrespective of the response condition, UDCA is recommended for routine administration in all PBC patients without contraindication. Ongoing clinical trials of second-line and additional therapy exhibit promising prospects.