BiliQML: a supervised machine-learning model to quantify biliary forms from digitized whole slide liver histopathological images.

The progress of research focused on cholangiocytes and the biliary tree during development and following injury is hindered by limited available quantitative methodologies. Current techniques include two-dimensional standard histological cell-counting approaches, which are rapidly performed, error prone, and lack architectural context or three-dimensional analysis of the biliary tree in opacified livers, which introduce technical issues along with minimal quantitation. The present study aims to fill these quantitative gaps with a supervised machine-learning model (BiliQML) able to quantify biliary forms in the liver of anti-keratin 19 antibody-stained whole slide images. Training utilized 5,019 researcher-labeled biliary forms, which following feature selection, and algorithm optimization, generated an F score of 0.87. Application of BiliQML on seven separate cholangiopathy models [genetic (Afp-CRE;Pkd1l1null/Fl, Alb-CRE;Rbp-jkfl/fl, and Albumin-CRE;ROSANICD), surgical (bile duct ligation), toxicological (3,5-diethoxycarbonyl-1,4-dihydrocollidine), and therapeutic (Cyp2c70-/- with ileal bile acid transporter inhibition)] allowed for a means to validate the capabilities and utility of this platform. The results from BiliQML quantification revealed biological and pathological differences across these seven diverse models, indicating a highly sensitive, robust, and scalable methodology for the quantification of distinct biliary forms. BiliQML is the first comprehensive machine-learning platform for biliary form analysis, adding much-needed morphologic context to standard immunofluorescence-based histology, and provides clinical and basic science researchers with a novel tool for the characterization of cholangiopathies.NEW & NOTEWORTHY BiliQML is the first comprehensive machine-learning platform for biliary form analysis in whole slide histopathological images. This platform provides clinical and basic science researchers with a novel tool for the improved quantification and characterization of biliary tract disorders.

Open hepatic artery flow with portal vein clamping protects against bile duct injury compared to pringles maneuver.

BACKGROUND: Conventional hepatic artery and portal vein clamping strategies can prevent blood loss and ischemia-reperfusion liver injury, and such preventative measures are the key to successful liver surgery. However, ischemic-induced damage to cholangiocytes is rarely considered. Here, we aimed to investigate the effect of different hepatic inflow interruption methods on bile duct injury. METHODS: Forty rats were randomly grouped as sham, Pringle maneuver (PM) and hepatic arterial blood flow open (HAFO) groups. We evaluated liver histology and function in liver sections, and biliary histology, cholangiocyte apoptosis and proliferation, cytokine production, and bile composition. RNA sequencing is performed to explore possible molecular mechanisms. The Blood-biliary barrier permeability and tight junctions were analyzed by HRP injection, immunofluorescence staining and analysis of ZO-1 expression by immunoblotting. RESULTS: HAFO significantly attenuated ischemia-induced liver injury and decreased ALT, ALP, TBIL, and DBIL levels in serum. The histopathological observations showed that bile duct injury in the PM group was more serious than that in the HAFO group. The numbers of apoptotic biliary epithelial cells in HAFO-treated rat bile ducta were lower than those in the PM group. RNA-seq showed that tight junctions may be related to the mechanism underlying the protective effect of HAFO, as shown by the reduced HRP levels and increased ZO-1 and claudin-1/3 expression in the HAFO group compared to the PM group. CONCLUSION: Compared with PM, HAFO alleviated the ischemic injury to the biliary system, which was characterized by decreased biliary epithelial cell apoptosis, reduced inflammatory responses and decreased blood-biliary-barrier permeability.

Restoration of Bile Duct Injury of Donor Livers During Ex Situ Normothermic Machine Perfusion.

BACKGROUND: End-ischemic ex situ normothermic machine perfusion (NMP) enables assessment of donor livers prior to transplantation. The objective of this study was to provide support for bile composition as a marker of biliary viability and to investigate whether bile ducts of high-risk human donor livers already undergo repair during NMP. METHODS: Forty-two livers that were initially declined for transplantation were included in our NMP clinical trial. After NMP, livers were either secondary declined (n = 17) or accepted for transplantation (n = 25) based on the chemical composition of bile and perfusate samples. Bile duct biopsies were taken before and after NMP and assessed using an established histological injury severity scoring system and a comprehensive immunohistochemical assessment focusing on peribiliary glands (PBGs), vascular damage, and regeneration. RESULTS: Bile ducts of livers that were transplanted after viability testing during NMP showed better preservation of PBGs, (micro)vasculature, and increased cholangiocyte proliferation, compared with declined livers. Biliary bicarbonate, glucose, and pH were confirmed as accurate biomarkers of bile duct vitality. In addition, we found evidence of PBG-based progenitor cell differentiation toward mature cholangiocytes during NMP. CONCLUSIONS: Favorable bile chemistry during NMP correlates well with better-preserved biliary microvasculature and PBGs, with a preserved capacity for biliary regeneration. During NMP, biliary tree progenitor cells start to differentiate toward mature cholangiocytes, facilitating restoration of the ischemically damaged surface epithelium.

Biliary hamartoma: a report of two cases.

Biliary hamartoma, also known as biliary micro hamartoma or Von Meyenburg complex, is a rare benign liver lesion, thought to be a ductal plate malformation rather than a true neoplasm. It is often seen incidentally on imagery or surgery as multiple small subcapsular nodules, scattered throughout the liver, making it likely to be mistaken for metastatic nodules. The histological presentation can also be deceptive, leading to the misdiagnosis of an adenocarcinoma of hepato-biliary differentiation or a metastasis. We hereby present two cases of biliary hamartoma, found incidentally on imagery and surgery, the first one in a 94-year-old woman, and the second in a 48-year-old man, which was initially misdiagnosed as an adenocarcinoma, along with a discussion of key clinical and pathological findings to help avoid this diagnostic pitfall.

Improvement of vanishing bile duct syndrome with hyperlipidemia.

A 75-year-old man was admitted to our hospital with acute onset of marked jaundice, elevated liver enzymes, and hyperlipidemia. He had been taking clopidogrel and pemafibrate for 3 months. He tested negative for autoantibodies and hepatitis-causing viruses. Gadoxetate-enhanced magnetic resonance imaging showed diffusely hypointense liver parenchyma in the hepatobiliary phase, with no appreciable excretion of gadoxetate into the biliary system. Histological examination of a liver specimen revealed disappearance of the bile ducts in the portal area and decreased expression of organic transporting polypeptide 1B3 on immunostaining. The patient was diagnosed with drug-induced vanishing bile duct syndrome and treated with ursodeoxycholic acid. The signs of liver dysfunction shown on blood chemistry tests improved spontaneously. After the acute hepatitis and lipid abnormalities had improved, repeat liver biopsy and gadoxetate-enhanced magnetic resonance imaging revealed improvement of the vanishing bile duct syndrome and recovery of the expression of organic transporting polypeptide 1B3. The reduction of OATP1B3 expression might be involved in the development of vanishing bile duct syndrome.

Differential expression of CK7, CK20, CDX2 in intestinal and pancreatobiliary types of preriampullary carcinoma.

CONTEXT: Incidence of periampullary carcinoma is low, approximately 0.5-2% of all gastrointestinal malignancies. Histologic subtyping has a prognostic bearing. The purpose of this study is to differentiate periampullary carcinomas based on immunohistochemistry (IHC) by using cytokeratin 7 (CK7), cytokeratin 20 (CK20), caudal type homeobox 2 (CDX2). AIMS: To analyze the usefulness of IHC as single/panel of markers that included CK7, CK20, and CDX2. SETTINGS AND DESIGN: This was a prospective study done from January 2017 to September 2018. SUBJECTS AND METHODS: A total 50 pancreaticoduodenectomy specimens were evaluated and classified as intestinal (INT) and pancreaticobiliary (PB) types based on their morphological and immunohistochemical features, respectively. The morphologic subtypes, expression of IHC markers were correlated with different histologic parameters. STATISTICAL ANALYSIS: Chi-square test was used to study the association between different IHC markers with histologic parameters. Probability (P) values <0.05 were regarded as statistically significant. RESULTS: The expression of CK7, CK20, CDX2 were studied in 50 cases to classify them as INT and pancreatobiliary subtypes. CK7 has high sensitivity (88.2%), CDX2 has high specificity (96.4%), CK20+/CDX2+ has both high sensitivity (94.2 percent) and specificity (89.2 percent) in differentiating INT from pancreatobiliary subtypes. The morphologic subtypes showed correlation with two variables (tumor grade, pathologic T stage). CK20 and CK20/CDX2 expression showed a positive correlation with tumor grade, pathologic T staging, and lymphovascular invasion. CONCLUSIONS: In conclusion, morphological classification can significantly discriminate histologic types, IHC plays a moderate role. However, the combined expression of CK20 and CDX2 is helpful in subtyping.

Vanishing bile duct syndrome following pembrolizumab infusion: case report and review of the literature.

PD-1/PD-L1 inhibitors demonstrate high efficacy in non-small-cell lung cancer and are now routinely used in clinical practice. Severe immune-related adverse events are reported in about 5% of patients, requiring hospitalization and possibly leading to death. We present a rare case of vanishing bile duct syndrome that arose a few days after the first pembrolizumab infusion. Laboratory tests and radiological imaging studies were performed to orient diagnosis and monitor the disease, while the evidence of ductal loss on the histological sample was pathognomonic for vanishing bile duct syndrome. High-dose steroid therapy and immunosuppressors were administered, resulting in scarce efficacy. Prompt recognition and management of similar conditions is crucial to avoid fatal events. Further studies are needed to investigate new drugs for steroid-refractory conditions.

Plain language summary Immunotherapy has demonstrated high efficacy in lung cancer and is commonly used in clinical practice. Despite the good tolerability, severe immune-related adverse events may occur, requiring hospitalization and possibly leading to death. We present a case of vanishing bile duct syndrome (a rare and potentially lethal condition characterized by progressive destruction of small bile ducts) which arose a few days after the first pembrolizumab infusion. Laboratory tests and radiological imaging were performed to orient diagnosis and monitor disease; a histological sample was required for vanishing bile duct syndrome diagnosis. High-dose steroid therapy and immunosuppressors were administered, with scarce efficacy. Prompt recognition and management of similar conditions is crucial to avoid fatal events. Further studies are needed to investigate new drugs for steroid-refractory conditions.

A human multi-lineage hepatic organoid model for liver fibrosis.

To investigate the pathogenesis of a congenital form of hepatic fibrosis, human hepatic organoids were engineered to express the most common causative mutation for Autosomal Recessive Polycystic Kidney Disease (ARPKD). Here we show that these hepatic organoids develop the key features of ARPKD liver pathology (abnormal bile ducts and fibrosis) in only 21 days. The ARPKD mutation increases collagen abundance and thick collagen fiber production in hepatic organoids, which mirrors ARPKD liver tissue pathology. Transcriptomic and other analyses indicate that the ARPKD mutation generates cholangiocytes with increased TGFß pathway activation, which are actively involved stimulating myofibroblasts to form collagen fibers. There is also an expansion of collagen-producing myofibroblasts with markedly increased PDGFRB protein expression and an activated STAT3 signaling pathway. Moreover, the transcriptome of ARPKD organoid myofibroblasts resemble those present in commonly occurring forms of liver fibrosis. PDGFRB pathway involvement was confirmed by the anti-fibrotic effect observed when ARPKD organoids were treated with PDGFRB inhibitors. Besides providing insight into the pathogenesis of congenital (and possibly acquired) forms of liver fibrosis, ARPKD organoids could also be used to test the anti-fibrotic efficacy of potential anti-fibrotic therapies.

Von Meyenburg Complexes: a starry sky.

The von Meyenburg complex (VMC) comprises of the bile duct hamartomas (BHs). VMCs are benign biliary malformations that originate from the disorganization of the small intrahepatic bile ducts. VMCs typically cause no symptoms or disturbances in the liver function; thus, in most instances, they are diagnosed incidentally. However, on some occasions, they are difficult to differentiate from other liver lesions, in particular from small liver metastases; imaging studies are usually noncontributory, and biopsy is necessary for a definite diagnosis. We describe the case of a 61-year-old man who presented with abdominal pain.

Human extrahepatic and intrahepatic cholangiocyte organoids show region-specific differentiation potential and model cystic fibrosis-related bile duct disease.

The development, homeostasis, and repair of intrahepatic and extrahepatic bile ducts are thought to involve distinct mechanisms including proliferation and maturation of cholangiocyte and progenitor cells. This study aimed to characterize human extrahepatic cholangiocyte organoids (ECO) using canonical Wnt-stimulated culture medium previously developed for intrahepatic cholangiocyte organoids (ICO). Paired ECO and ICO were derived from common bile duct and liver tissue, respectively. Characterization showed both organoid types were highly similar, though some differences in size and gene expression were observed. Both ECO and ICO have cholangiocyte fate differentiation capacity. However, unlike ICO, ECO lack the potential for differentiation towards a hepatocyte-like fate. Importantly, ECO derived from a cystic fibrosis patient showed no CFTR channel activity but normal chloride channel and MDR1 transporter activity. In conclusion, this study shows that ECO and ICO have distinct lineage fate and that ECO provide a competent model to study extrahepatic bile duct diseases like cystic fibrosis.

Determining the Indeterminate Biliary Stricture: Cholangioscopy and Beyond.

PURPOSE OF REVIEW: Indeterminate biliary strictures (IDBS) continue to be an area of frustration for clinicians. Standard endoscopic retrograde cholangiopancreatography (ERCP) with conventional brush cytology and/or forceps biopsy has a low sensitivity for distinguishing benign from malignant biliary strictures. A delay in diagnosis of malignancy has consequences for subsequent therapy or surgery. In this article, we review current and emerging technologies that may aid in this diagnostic dilemma. RECENT FINDINGS: Several technologies have been utilized in IDBS to establish a diagnosis which include peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound with fine needle aspiration, intraductal ultrasound, optical coherence tomography, fluorescence in situ hybridization, next generation sequencing, integrated molecular pathology, and DNA-image cytometry. While cholangioscopy and confocal laser endomicroscopy have become standards of care in expert centers for the evaluation of patients with IDBS, there are several endoscopic and molecular modalities that may also aid in establishing a diagnosis. Further head-to-head prospective diagnostic studies as well as cost-efficacy studies are needed.

Non-canonical Wnt signalling regulates scarring in biliary disease via the planar cell polarity receptors.

The number of patients diagnosed with chronic bile duct disease is increasing and in most cases these diseases result in chronic ductular scarring, necessitating liver transplantation. The formation of ductular scaring affects liver function; however, scar-generating portal fibroblasts also provide important instructive signals to promote the proliferation and differentiation of biliary epithelial cells. Therefore, understanding whether we can reduce scar formation while maintaining a pro-regenerative microenvironment will be essential in developing treatments for biliary disease. Here, we describe how regenerating biliary epithelial cells express Wnt-Planar Cell Polarity signalling components following bile duct injury and promote the formation of ductular scars by upregulating pro-fibrogenic cytokines and positively regulating collagen-deposition. Inhibiting the production of Wnt-ligands reduces the amount of scar formed around the bile duct, without reducing the development of the pro-regenerative microenvironment required for ductular regeneration, demonstrating that scarring and regeneration can be uncoupled in adult biliary disease and regeneration.

Clinical implications of elevated serum interleukin-6 in IgG4-related disease.

INTRODUCTION: Some patients with IgG4-related disease (IgG4-RD) exhibit elevated serum interleukin (IL)-6 with excessive inflammatory reactions or with repeating relapse. To date few reports pertaining to clinical implications of elevated serum IL-6 in IgG4-RD patients have been published. The aims of the current retrospective study were to investigate the clinical implications of elevated serum IL-6 in IgG4-RD patients, and to examine whether IL-6 can predict the activity and/or relapse of the disease. MATERIALS AND METHODS: We examined the clinical picture at the onset of 43 patients who were diagnosed with IgG4-RD in our hospital and were able to measure serum IL-6 before steroid treatment. RESULTS: The median level of serum IL-6 was 2.2 pg/mL. There was a significant correlation between IL-6 and C-reactive protein (CRP) level (r = 0.397, p = 0.008), hemoglobin level (r = -0.390, p = 0.010) and albumin level (r = -0.556, p < 0.001). When 43 patients were divided into two groups by using a cut-off IL-6 of 4 pg/mL, the high IL-6 group showed higher age, lower albumin, higher CRP and higher aspartate aminotransferase (AST) (age p = 0.014, albumin p = 0.006, CRP p <0.001, AST p = 0.009). Hepatic swelling and splenomegaly were significantly more prevalent in the high IL-6 group than it was in the low IL-6 group (liver p < 0.001, spleen p = 0.020). Biliary tract involvement tended to admit more in the high IL-6 group (p = 0.060). CONCLUSION: Serum IL-6 level at the onset of IgG4-RD may be significantly correlated with clinical inflammatory parameters and it may also be associated with involvement of the bile duct, liver, and spleen.

If It Looks Like a Duct and Acts Like a Duct: On the Role of Reprogrammed Hepatocytes in Cholangiopathies.

Cholangiopathies are chronic, progressive diseases of the biliary tree, and can be either acquired or genetic. The primary target is the cholangiocyte (CC), the cell type lining the bile duct that is responsible for bile modification and transport. Despite advances in our understanding and diagnosis of these diseases in recent years, there are no proven therapeutic treatments for the majority of the cholangiopathies, and liver transplantation is the only life-extending treatment option for patients with end-stage cholestatic liver disease. One potential therapeutic strategy is to facilitate endogenous repair of the biliary system, which may alleviate intrahepatic cholestasis caused by these diseases. During biliary injury, hepatocytes (HC) are known to alter their phenotype and acquire CC-like features, a process known as cellular reprogramming. This brief review discusses the potential ways in which reprogrammed HC may contribute to biliary repair, thereby restoring bile flow and reducing the severity of cholangiopathies. Some of these include modifying bile to reduce toxicity, serving as a source of de novo CC to repair the biliary epithelium, or creating new channels to facilitate bile flow.

Nivolumab-induced large-duct cholangiopathy treated with ursodeoxycholic acid and tocilizumab.

Immune checkpoint inhibitor therapy has become a cornerstone in the management of many oncologic diseases. Although it is well tolerated in most patients, a wide spectrum of adverse events has been described as a result of immune system alteration. We present a case of a woman with metastatic bronchogenic adenocarcinoma who was initially thought to have immune-mediated hepatitis, but eventually discovered to have a rarely described immune-mediated cholangiopathy. Her cholangiopathy appeared to stabilize following ursodeoxycholic acid and tocilizumab after several lines of guideline-directed therapy. Awareness of this unique toxicity following immune checkpoint inhibitor, and potential treatment options may help clinicians manage this rare but serious complication.

Pancreaticobiliary involvement in treated type 1 autoimmune pancreatitis: Imaging pattern and risk factors for disease relapse.

PURPOSE: To evaluate the imaging pattern of pancreaticobiliary lesions in patients with treated type 1AIP, to determine the incidence of disease relapse and malignancy, and to identify the risk factors. METHOD: The institutional review board approval was acquired. All patients gave written informed consent. From a prospective clinico-radiological database since 2012, consecutive patients with type 1 AIP who were treated and followed up (≥18 months) were identified. The presence/absence of pancreaticobiliary lesion(s) development during follow-up were assessed. The etiology was determined and the imaging pattern was compared to the initial attack. Risk factors were identified by univariate and multivariate analysis. RESULTS: Among 103 patients with treated type 1 AIP, 44 (42.7%) developed pancreaticobiliary lesions during follow up (median time interval to initial diagnosis: 17 months, range 3-62 months), mostly after steroid discontinuation (63.6%) or during maintenance therapy (29.5%). All lesions were disease relapse, which responded to steroid treatment. At relapse, pancreatic involvement was less frequent (81.8% vs 100%, p = 0.003), and the pancreas size was smaller (p < 0.01), whereas extra-pancreatic bile duct (ExPanBD) involvement was more severe and extensive (both p < 0.01). Multivariate analysis revealed ExPanBD involvement at initial diagnosis (hazard ratio 2.437, 95% CI 1.343-7.402, p = 0.002) and serum IgG4 response ratio at the induction phase (hazard ratio 0.357, 95% CI 0.055-0.804, p = 0.011) as significant independent predictors of relapse. CONCLUSIONS: In treated type 1 AIP, although imaging pattern may differ, pancreaticobiliary lesions are usually manifestations of disease relapse. ExPanBD involvement and poor serum response suggests high risk of relapse.