Final Results from the First European Real-World Experience on Lusutrombopag Treatment in Cirrhotic Patients with Severe Thrombocytopenia: Insights from the REAl-World Lusutrombopag Treatment in ITalY Study.

Background and aims: Management of severe thrombocytopenia poses significant challenges in patients with chronic liver disease. Here, we aimed to evaluate the first real-world European post-marketing cohort of cirrhotic patients treated with lusutrombopag, a thrombopoietin receptor agonist, verifying the efficacy and safety of the drug. Methods: In the REAl-world Lusutrombopag treatment in ITalY (REALITY) study, we collected data from consecutive cirrhotic patients treated with lusutrombopag in 19 Italian hepatology centers, mostly joined to the "Club Epatologi Ospedalieri" (CLEO). Primary and secondary efficacy endpoints were the ability of lusutrombopag to avoid platelet transfusions and to raise the platelet count to ≥50,000/µL, respectively. Treatment-associated adverse events were also collected. Results: A total of 66 patients and 73 cycles of treatment were included in the study, since 5 patients received multiple doses of lusutrombopag over time for different invasive procedures. Fourteen patients (19%) had a history of portal vein thrombosis (PVT). Lusutrombopag determined a significant increase in platelet count [from 37,000 (33,000-44,000/µL) to 58,000 (49,000-82,000), p < 0.001]. The primary endpoint was met in 84% of patients and the secondary endpoint in 74% of patients. Baseline platelet count was the only independent factor associated with response in multivariate logistic regression analysis (OR for any 1000 uL of 1.13, CI95% 1.04-1.26, p 0.01), with a good discrimination power (AUROC: 0.78). Notably, a baseline platelet count ≤ 29,000/µL was identified as the threshold for identifying patients unlikely to respond to the drug (sensitivity of 91%). Finally, de novo PVT was observed in four patients (5%), none of whom had undergone repeated treatment, and no other safety or hemorrhagic events were recorded in the entire population analyzed. Conclusions: In this first European real-world series, lusutrombopag demonstrated efficacy and safety consistent with the results of registrational studies. According to our results, patients with baseline platelet counts ≤29,000/µL are unlikely to respond to the drug.

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation.

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

Clinical management of liver cyst infections: an international, modified Delphi-based clinical decision framework.

Liver cyst infections often necessitate long-term hospital admission and are associated with considerable morbidity and mortality. We conducted a modified Delphi study to reach expert consensus for a clinical decision framework. The expert panel consisted of 24 medical specialists, including 12 hepatologists, from nine countries across Europe, North America, and Asia. The Delphi had three rounds. The first round (response rate 21/24 [88%]) was an online survey with questions constructed from literature review and expert opinion, in which experts were asked about their management preferences and rated possible management strategies for seven clinical scenarios. Experts also rated 14 clinical decision-making items for relevancy and defined treatment outcomes. During the second round (response rate 13/24 [54%]), items that did not reach consensus and newly suggested themes were discussed in an online panel meeting. In the third round (response rate 16/24 [67%]), experts voted on definitions and management strategies using an online survey based on previous answers. Consensus was predefined as a vote threshold of at least 75%. We identified five subclassifications of liver cyst infection according to cyst phenotypes and patient immune status and consensus on episode definitions (new, persistent, and recurrent) and criteria for treatment success or failure was reached. The experts agreed that fever and elevated C-reactive protein are pivotal decision-making items for initiating and evaluating the management of liver cyst infections. Consensus was reached on 26 management statements for patients with liver cyst infections across multiple clinical scenarios, including two treatment algorithms, which were merged into one after comments. We provide a clinical decision framework for physicians managing patients with liver cyst infections. This framework will facilitate uniformity in the management of liver cyst infections and can constitute the basis for the development of future guidelines.

Development and Validation of a Scoring System to Predict Response to Obeticholic Acid in Primary Biliary Cholangitis.

BACKGROUND & AIMS: Obeticholic acid (OCA) is the only licensed second-line therapy for primary biliary cholangitis (PBC). With novel therapeutics in advanced development, clinical tools are needed to tailor the treatment algorithm. We aimed to derive and externally validate the OCA response score (ORS) for predicting the response probability of individuals with PBC to OCA. METHODS: We used data from the Italian RECAPITULATE (N = 441) and the IBER-PBC (N = 244) OCA real-world prospective cohorts to derive/validate a score including widely available variables obtained either pre-treatment (ORS) or also after 6 months of treatment (ORS+). Multivariable Cox regressions with backward selection were applied to obtain parsimonious predictive models. The predicted outcomes were biochemical response according to POISE (alkaline phosphatase [ALP]/upper limit of normal [ULN]<1.67 with a reduction of at least 15%, and normal bilirubin), or ALP/ULN<1.67, or Normal range criteria (NR: normal ALP, alanine aminotransferase [ALT], and bilirubin) up to 24 months. RESULTS: Depending on the response criteria, ORS included age, pruritus, cirrhosis, ALP/ULN, ALT/ULN, GGT/ULN, and bilirubin. ORS+ also included ALP/ULN and bilirubin after 6 months of OCA therapy. Internally validated c-statistics for ORS were 0.75, 0.78, and 0.72 for POISE, ALP/ULN<1.67, and NR response, which raised to 0.83, 0.88, and 0.81 with ORS+, respectively. The respective performances in validation were 0.70, 0.72, and 0.71 for ORS and 0.80, 0.84, and 0.78 for ORS+. Results were consistent across groups with mild/severe disease. CONCLUSIONS: We developed and externally validated a scoring system capable to predict OCA response according to different criteria. This tool will enhance a stratified second-line therapy model to streamline standard care and trial delivery in PBC.

Transjugular Intrahepatic Portosystemic Shunt as a Bridge to Abdominal Surgery in Cirrhosis.

Abdominal surgery is associated with high postoperative mortality and morbidity in cirrhotic patients. Despite improvements in surgical techniques, clinical management, and intensive care, the outcome could be influenced by the degree of portal hypertension, the severity of hepatopathy, or the type of surgery. Preoperative transjugular intrahepatic portosystemic shunt (TIPS) placement, in addition to medical therapy, plays an important role in managing the complications of portal hypertension such as ascites, hepatic encephalopathy, variceal bleeding or portal vein thrombosis. To date, the improvement of post-surgery outcomes in cirrhotic patients after TIPS placement remains unclear. Only observational data existing in the literature and prospective studies are urgently needed to evaluate the efficacy and safety of TIPS in this setting. This review aims to outline the role of TIPS as a tool in postoperative complications reduction in cirrhotic patients, both in the setting of emergency and elective surgery.

Biliary stem cells in health and cholangiopathies and cholangiocarcinoma.

PURPOSE OF REVIEW: This review discusses evidence regarding progenitor populations of the biliary tree in the tissue regeneration and homeostasis, and the pathobiology of cholangiopathies and malignancies. RECENT FINDINGS: In embryogenesis biliary multipotent progenitor subpopulation contributes cells not only to the pancreas and gall bladder but also to the liver. Cells equipped with a constellation of markers suggestive of the primitive endodermal phenotype exist in the peribiliary glands, the bile duct glands, of the intra- and extrahepatic bile ducts. These cells are able to be isolated and cultured easily, which demonstrates the persistence of a stable phenotype during in vitro expansion, the ability to self-renew in vitro, and the ability to differentiate between hepatocyte and biliary and pancreatic islet fates. SUMMARY: In normal human livers, stem/progenitors cells are mostly restricted in two distinct niches, which are the bile ductules/canals of Hering and the peribiliary glands (PBGs) present inside the wall of large intrahepatic bile ducts. The existence of a network of stem/progenitor cell niches within the liver and along the entire biliary tree inform a patho-biological-based translational approach to biliary diseases and cholangiocarcinoma since it poses the basis to understand biliary regeneration after extensive or chronic injuries and progression to fibrosis and cancer.

Intrahepatic cholangiocarcinoma: Evolving strategies in management and treatment.

Intrahepatic cholangiocarcinoma is the second most frequent primary liver cancer after hepatocellular carcinoma. According to International Classification of Diseases-11 (ICD-11), intrahepatic cholangiocarcinoma is identified by a specific diagnostic code, different with respect to perihilar-CCA or distal-CCA. Intrahepatic cholangiocarcinoma originates from intrahepatic small or large bile ducts including the second-order bile ducts and has a silent presentation that combined with the highly aggressive nature and refractoriness to chemotherapy contributes to the alarming increasing incidence and mortality. Indeed, at the moment of the diagnosis, less than 40% of intrahepatic cholangiocarcinoma are suitable of curative surgical therapy, that is so far the only effective treatment. The main goals of clinicians and researchers are to make an early diagnosis, and to carry out molecular characterization to provide the patient with personalized treatment. Unfortunately, these goals are not easily achievable because of the heterogeneity of this tumor from anatomical, molecular, biological, and clinical perspectives. However, recent progress has been made in molecular characterization, surgical treatment, and management of intrahepatic cholangiocarcinoma and, this article deals with these advances.

Impact of SARS-CoV-2 vaccination on FcγRIIIA/CD16 dynamics in Natural Killer cells: relevance for antibody-dependent functions.

Introduction: Natural Killer (NK) cells contribute to the protective effects of vaccine-induced antibodies thanks to the low affinity receptor for IgG, FcγRIIIA/CD16, whose aggregation leads to the killing of infected cells and IFNγ release, through which they potentiate adaptive immune responses. Methods: Forty-seven healthy young individuals undergoing either homologous (ChAdOx1-S/ChAdOx1-S) or heterologous (ChAdOx1-S/BNT162B2) SARS-CoV-2 vaccination settings were recruited. Peripheral blood samples were collected immediately prior to vaccination and 8 weeks after the booster dose. The phenotypic and functional profile of NK cells was evaluated by flow cytometry at both time points. Serum samples were tested to evaluate circulating anti-Spike IgG levels and cytomegalovirus serostatus. CD16 F158V polymorphism was assessed by sequencing analysis. Results: The downregulation of CD16 and the selective impairment of antibody-dependent cytotoxicity and IFNγ production in CD56dim NK population, persisting 8 weeks after boosting, were observed in heterologous, but not in homologous SARS-CoV-2 vaccination scheme. While the magnitude of CD16-dependent functions of the global CD56dim pool correlated with receptor levels before and after vaccination, the responsivity of NKG2C+ subset, that displays amplified size and functionality in HCMV+ individuals, resulted intrinsically insensitive to CD16 levels. Individual CD16 responsiveness was also affected by CD16F158V polymorphism; F/F low affinity individuals, characterized by reduced CD16 levels and functions independently of vaccination, did not show post-vaccinal functional impairment with respect to intermediate and high affinity ones, despite a comparable CD16 downregulation. Further, CD16 high affinity ligation conditions by means of afucosylated mAb overcame vaccine-induced and genotype-dependent functional defects. Finally, the preservation of CD16 expression directly correlated with anti-Spike IgG titer, hinting that the individual magnitude of receptor-dependent functions may contribute to the amplification of the vaccinal response. Conclusion: This study demonstrates a durable downmodulation of CD16 levels and Ab-dependent NK functions after SARS-CoV-2 heterologous vaccination, and highlights the impact of genetic and environmental host-related factors in modulating NK cell susceptibility to post-vaccinal Fc-dependent functional impairment.

Rifaximin Reduces Risk of All-Cause Hospitalization in Cirrhotic Liver Transplant Candidates with Hepatic Encephalopathy.

In cirrhotic patients listed for liver transplantation (LT) with a history of hepatic encephalopathy (HE), rifaximin reduces the number of hospitalizations, but whether it influences the time to first hospitalization is unknown. AIMS: to evaluate the time-dependent impact of rifaximin on the risk of all-cause hospitalization and dropout in patients on the LT waiting list. METHODS: Consecutive patients listed for LT were retrospectively enrolled. After balancing populations with and without rifaximin treatment using the inverse probability therapy weighting analysis, Fine-Gray multivariable competing risk analyses were run to explore risk factors for the first episode of hospitalization and dropout. RESULTS: When comparing 92 patients taking rifaximin to the untreated group of 152, rifaximin treatment was not associated with any of the study outcomes. In the subset of patients with a history of HE at waitlist entry (N = 81 rifaximin-treated and N = 39 untreated), rifaximin intake was independently associated with a lower risk of hospitalization for all causes (SHR 0.638; 95.0% CI 0.418-0.973; p = 0.037) and for HE (SHR 0.379; 95.0% CI 0.207-0.693; p = 0.002). CONCLUSIONS: cirrhotic LT candidates with a prior history of HE rifaximin treatment are associated with a lower risk of time-dependent all-cause hospitalization, likely due to its unique effect on gut microbiome composition/function.

A postnatal network of co-hepato/pancreatic stem/progenitors in the biliary trees of pigs and humans.

A network of co-hepato/pancreatic stem/progenitors exists in pigs and humans in Brunner's Glands in the submucosa of the duodenum, in peribiliary glands (PBGs) of intrahepatic and extrahepatic biliary trees, and in pancreatic duct glands (PDGs) of intrapancreatic biliary trees, collectively supporting hepatic and pancreatic regeneration postnatally. The network is found in humans postnatally throughout life and, so far, has been demonstrated in pigs postnatally at least through to young adulthood. These stem/progenitors in vivo in pigs are in highest numbers in Brunner's Glands and in PDGs nearest the duodenum, and in humans are in Brunner's Glands and in PBGs in the hepato/pancreatic common duct, a duct missing postnatally in pigs. Elsewhere in PDGs in pigs and in all PDGs in humans are only committed unipotent or bipotent progenitors. Stem/progenitors have genetic signatures in liver/pancreas-related RNA-seq data based on correlation, hierarchical clustering, differential gene expression and principal component analyses (PCA). Gene expression includes representative traits of pluripotency genes (SOX2, OCT4), endodermal transcription factors (e.g. SOX9, SOX17, PDX1), other stem cell traits (e.g. NCAM, CD44, sodium iodide symporter or NIS), and proliferation biomarkers (Ki67). Hepato/pancreatic multipotentiality was demonstrated by the stem/progenitors' responses under distinct ex vivo conditions or in vivo when patch grafted as organoids onto the liver versus the pancreas. Therefore, pigs are logical hosts for translational/preclinical studies for cell therapies with these stem/progenitors for hepatic and pancreatic dysfunctions.

A predictive decision support system for coronavirus disease 2019 response management and medical logistic planning.

Objective: Coronavirus disease 2019 demonstrated the inconsistencies in adequately responding to biological threats on a global scale due to a lack of powerful tools for assessing various factors in the formation of the epidemic situation and its forecasting. Decision support systems have a role in overcoming the challenges in health monitoring systems in light of current or future epidemic outbreaks. This paper focuses on some applied examples of logistic planning, a key service of the Earth Cognitive System for Coronavirus Disease 2019 project, here presented, evidencing the added value of artificial intelligence algorithms towards predictive hypotheses in tackling health emergencies. Methods: Earth Cognitive System for Coronavirus Disease 2019 is a decision support system designed to support healthcare institutions in monitoring, management and forecasting activities through artificial intelligence, social media analytics, geospatial analysis and satellite imaging. The monitoring, management and prediction of medical equipment logistic needs rely on machine learning to predict the regional risk classification colour codes, the emergency rooms attendances, and the forecast of regional medical supplies, synergically enhancing geospatial and temporal dimensions. Results: The overall performance of the regional risk colour code classifier yielded a high value of the macro-average F1-score (0.82) and an accuracy of 85%. The prediction of the emergency rooms attendances for the Lazio region yielded a very low root mean square error (<11 patients) and a high positive correlation with the actual values for the major hospitals of the Lazio region which admit about 90% of the region's patients. The prediction of the medicinal purchases for the regions of Lazio and Piemonte has yielded a low root mean squared percentage error of 16%. Conclusions: Accurate forecasting of the evolution of new cases and drug utilisation enables the resulting excess demand throughout the supply chain to be managed more effectively. Forecasting during a pandemic becomes essential for effective government decision-making, managing supply chain resources, and for informing tough policy decisions.

Cell transplantation-based regenerative medicine in liver diseases.

This review aims to evaluate the current preclinical state of liver bioengineering, the clinical context for liver cell therapies, the cell sources, the delivery routes, and the results of clinical trials for end-stage liver disease. Different clinical settings, such as inborn errors of metabolism, acute liver failure, chronic liver disease, liver cirrhosis, and acute-on-chronic liver failure, as well as multiple cellular sources were analyzed; namely, hepatocytes, hepatic progenitor cells, biliary tree stem/progenitor cells, mesenchymal stromal cells, and macrophages. The highly heterogeneous clinical scenario of liver disease and the availability of multiple cellular sources endowed with different biological properties make this a multidisciplinary translational research challenge. Data on each individual liver disease and more accurate endpoints are urgently needed, together with a characterization of the regenerative pathways leading to potential therapeutic benefit. Here, we critically review these topics and identify related research needs and perspectives in preclinical and clinical settings.

Role of the Gut-Liver Axis in the Pathobiology of Cholangiopathies: Basic and Clinical Evidence.

The "Gut-Liver Axis" refers to the physiological bidirectional interplay between the gut and its microbiota and the liver which, in health, occurs thanks to a condition of immune tolerance. In recent years, several studies have shown that, in case of a change in gut bacterial homeostasis or impairment of intestinal barrier functions, cholangiocytes, which are the epithelial cells lining the bile ducts, activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Intestinal dysbiosis or impaired intestinal barrier functions cause cholangiocytes to be exposed to an increasing amount of microorganisms that can reactivate inflammatory responses, thus inducing the onset of liver fibrosis. The present review focuses on the role of the gut-liver axis in the pathogenesis of cholangiopathies.

Criteria for preclinical models of cholangiocarcinoma: scientific and medical relevance.

Cholangiocarcinoma (CCA) is a rare malignancy that develops at any point along the biliary tree. CCA has a poor prognosis, its clinical management remains challenging, and effective treatments are lacking. Therefore, preclinical research is of pivotal importance and necessary to acquire a deeper understanding of CCA and improve therapeutic outcomes. Preclinical research involves developing and managing complementary experimental models, from in vitro assays using primary cells or cell lines cultured in 2D or 3D to in vivo models with engrafted material, chemically induced CCA or genetically engineered models. All are valuable tools with well-defined advantages and limitations. The choice of a preclinical model is guided by the question(s) to be addressed; ideally, results should be recapitulated in independent approaches. In this Consensus Statement, a task force of 45 experts in CCA molecular and cellular biology and clinicians, including pathologists, from ten countries provides recommendations on the minimal criteria for preclinical models to provide a uniform approach. These recommendations are based on two rounds of questionnaires completed by 35 (first round) and 45 (second round) experts to reach a consensus with 13 statements. An agreement was defined when at least 90% of the participants voting anonymously agreed with a statement. The ultimate goal was to transfer basic laboratory research to the clinics through increased disease understanding and to develop clinical biomarkers and innovative therapies for patients with CCA.

Human duodenal submucosal glands contain a defined stem/progenitor subpopulation with liver-specific regenerative potential.

BACKGROUND & AIMS: Common precursors for the liver, biliary tree, and pancreas exist at an early stage of development in the definitive endoderm forming the foregut. We have identified and characterised endodermal stem/progenitor cells with regenerative potential persisting in the adult human duodenum. METHODS: Human duodena were obtained from organ donors, and duodenal submucosal gland cells were isolated after removal of the mucosa layer. Cells were cultured on plastic or as organoids and were transplanted into severe combined immunodeficient (SCID) mouse livers. RESULTS: In situ studies of submucosal glands in the human duodenum revealed cells expressing stem/progenitor cell markers that had unique phenotypic traits distinguishable from intestinal crypt cells. Genetic signature studies indicated that the cells are closer to biliary tree stem cells and to definitive endodermal cells than to adult hepatocytes, supporting the interpretation that they are endodermal stem/progenitor cells. In vitro, human duodenal submucosal gland cells demonstrated clonal growth, capability to form organoids, and ability to acquire functional hepatocyte traits. In vivo, transplanted cells engrafted into the livers of immunocompromised mice and differentiated to mature liver cells. In an experimental model of fatty liver, human duodenal submucosal gland cells were able to rescue hosts from liver damage by supporting repopulation and regeneration of the liver. CONCLUSIONS: A cell population with clonal growth and organoid formation capability, which has liver differentiation potency in vitro and in vivo in murine experimental models, is present within adult duodenal submucosal glands. These cells can be isolated, do not require reprogramming, and thus could potentially represent a novel cell source for regenerative medicine of the liver. IMPACT AND IMPLICATIONS: Cell therapies for liver disease could represent an option to support liver function, but the identification of sustainable and viable cell sources is critical. Here, we describe a cell population with organoid formation capability and liver-specific regenerative potential in submucosal glands of the human duodenum. Duodenal submucosal gland cells are isolated from adult organs, do not require reprogramming, and could rescue hepatocellular damage in preclinical models of chronic, but not acute, liver injury. Duodenal submucosal gland cells could represent a potential candidate cell source for regenerative medicine of the liver, but the determination of cell dose and toxicity is needed before clinical testing in humans.

Secretin alleviates biliary and liver injury during late-stage primary biliary cholangitis via restoration of secretory processes.

BACKGROUND & AIMS: Primary biliary cholangitis (PBC) is characterised by ductopenia, ductular reaction, impairment of anion exchanger 2 (AE2) and the 'bicarbonate umbrella'. Ductulo-canalicular junction (DCJ) derangement is hypothesised to promote PBC progression. The secretin (Sct)/secretin receptor (SR) axis regulates cystic fibrosis transmembrane receptor (CFTR) and AE2, thus promoting choleresis. We evaluated the role of Sct/SR signalling on biliary secretory processes and subsequent injury in a late-stage PBC mouse model and human samples. METHODS: At 32 weeks of age, female and male wild-type and dominant-negative transforming growth factor beta receptor II (late-stage PBC model) mice were treated with Sct for 1 or 8 weeks. Bulk RNA-sequencing was performed in isolated cholangiocytes from mouse models. RESULTS: Biliary Sct/SR/CFTR/AE2 expression and bile bicarbonate levels were reduced in late-stage PBC mouse models and human samples. Sct treatment decreased bile duct loss, ductular reaction, inflammation, and fibrosis in late-stage PBC models. Sct reduced hepatic bile acid levels, modified bile acid composition, and restored the DCJ and 'bicarbonate umbrella'. RNA-sequencing identified that Sct promoted mature epithelial marker expression, specifically anterior grade protein 2 (Agr2). Late-stage PBC models and human samples exhibited reduced biliary mucin 1 levels, which were enhanced by Sct treatment. CONCLUSION: Loss of Sct/SR signalling in late-stage PBC results in a faulty 'bicarbonate umbrella' and reduced Agr2-mediated mucin production. Sct restores cholangiocyte secretory processes and DCJ formation through enhanced mature cholangiocyte phenotypes and bile duct growth. Sct treatment may be beneficial for individuals with late-stage PBC. IMPACT AND IMPLICATIONS: Secretin (Sct) regulates biliary proliferation and bicarbonate secretion in cholangiocytes via its receptor, SR, and in mouse models and human samples of late-stage primary biliary cholangitis (PBC), the Sct/SR axis is blunted along with loss of the protective 'bicarbonate umbrella'. We found that both short- and long-term Sct treatment ameliorated ductular reaction, immune cell influx, and liver fibrosis in late-stage PBC mouse models. Importantly, Sct treatment promoted bicarbonate and mucin secretion and hepatic bile acid efflux, thus reducing cholestatic and toxic bile acid-associated injury in late-stage PBC mouse models. Our work perpetuates the hypothesis that PBC pathogenesis hinges on secretory defects, and restoration of secretory processes that promote the 'bicarbonate umbrella' may be important for amelioration of PBC-associated damage.

Role of ductular reaction and ductular-canalicular junctions in identifying severe primary biliary cholangitis.

Background & Aims: Primary biliary cholangitis (PBC) is a chronic cholangiopathy characterised by immuno-mediated injury of interlobular bile ducts leading to intrahepatic cholestasis and progressive liver fibrosis. PBC histology is characterised by portal inflammation, progressive fibrosis, ductopenia, and the appearance of the so-called ductular reaction. The aim of the present study was to investigate the pathogenetic relevance of ductular reaction in PBC. Methods: Liver biopsies were collected from naïve people with PBC (N = 87). Clinical-serological parameters were obtained at diagnosis and after 1 year of ursodeoxycholic acid (UDCA) treatment. Histological staging was performed on all slides according to multiple scoring systems and criteria for PBC. Liver samples were obtained from Mdr2 -/- mice treated with or without UDCA. Samples were processed for histology, immunohistochemistry, and immunofluorescence. Results: Ductular reaction in people with PBC correlated with the disease stage and liver fibrosis, but not with disease activity; an extensive ductular reaction correlated with serum alkaline phosphatase levels at diagnosis, response to UDCA, and individuals' estimated survival, independently from other histological parameters, including disease stage. In people with PBC, reactive ductules were associated with the establishment of junctions with bile canaliculi and with fibrogenetic cell activation. Consistently, in a mouse model of intrahepatic cholestasis, UDCA treatment was effective in reducing ductular reaction and fibrosis and increasing ductular-canalicular junctions. Conclusions: Extensive ductular reaction outlines a severe histologic phenotype in PBC and is associated with an inadequate therapy response and a worse estimated prognosis. Lay summary: In people affected by primary biliary cholangitis (PBC), the histological appearance of extensive ductular reaction identifies individuals at risk of progressive fibrosis. Ductular reaction at diagnosis correlates with the lack of response to first-line therapy with ursodeoxycholic acid and serves to restore ductular-canalicular junctions in people with PBC. Assessing ductular reaction extension at diagnosis may add valuable information for clinicians.