Damaged Bile Ducts Research Articles

Langerhans Cell Histiocytosis or Acute Cellular Rejection?

Langerhans cell histiocytosis (LCH) is a rare malignant disorder of epidermal antigen presenting cells. It is characterized by infiltration of various tissues with dendritic cells (Langerhans cells, LC) that express CD1a or CD207 (langerin), often leading to organ dysfunction. A patient with LCH required liver transplantation (LT) for LCH-associated biliary-tract disease. Cholangiopathy developed after LT. The question arose: In this patient, did LC in damaged liver-allograft biliary epithelium signify acute cellular rejection (ACR) or recurrent LCH? We evaluated immunohistochemical identification of LC (CD1a, CD207) in the proposita and in 14 ACR patient samples as distinguishing between ACR and recurrent LCH. Among 15 patient samples, 3 (20%) marked with neither antibody. Among the remaining 12 samples (80%), 4 (26.7%)-including that from the proposita-had cells marking for both antigens within bile-duct epithelium as well as in surrounding portal-tract connective tissue, 2 (13.3%) had cells marking for both antigens in one region or the other, but not in both, and 6 (40%) had cells marking for only one antigen in one region or the other. Immunostaining for CD1a and CD207/langerin in the setting of ACR without suspicion of LCH identifies LC in damaged bile ducts. This biomarker pairing proved not to be LCH-specific. Our findings indicate that the presence of these cells alone is insufficient to identify recurrent LCH in the allograft liver.

Recombinant collagen coating 3D printed PEGDA hydrogel tube loading with differentiable BMSCs to repair bile duct injury

Bile duct injury presents a significant clinical challenge following hepatobiliary surgery, necessitating advancements in the repair of damaged bile ducts is a persistent issue in biliary surgery. 3D printed tubular scaffolds have emerged as a promising approach for the repair of ductal tissues, yet the development of scaffolds that balance exceptional mechanical properties with biocompatibility remains an ongoing challenge. This study introduces a novel, bio-fabricated bilayer bile duct scaffold using a 3D printing technique. The scaffold comprises an inner layer of polyethylene glycol diacrylate (PEGDA) to provide high mechanical strength, and an outer layer of biocompatible, methacryloylated recombinant collagen type III (rColMA) loaded with basic fibroblast growth factor (bFGF)-encapsulated liposomes (bFGF@Lip). This design enables the controlled release of bFGF, creating an optimal environment for the growth and differentiation of bone marrow mesenchymal stem cells (BMSCs) into cholangiocyte-like cells. These cells are instrumental in the regeneration of bile duct tissues, evidenced by the pronounced expression of cholangiocyte differentiation markers CK19 and CFTR. The PEGDA//rColMA/bFGF@Lip bilayer bile duct scaffold can well simulate the bile duct structure, and the outer rColMA/bFGF@Lip hydrogel can well promote the growth and differentiation of BMSCs into bile duct epithelial cells. In vivo experiments showed that the scaffold did not cause cholestasis in the body. This new in vitro pre-differentiated active 3D printed scaffold provides new ideas for the study of bile duct tissue replacement.

Conventional type 1 dendritic cells are essential for the development of primary biliary cholangitis.

Primary biliary cholangitis (PBC) is a progressive-cholestatic autoimmune liver disease. Dendritic cells (DC) are professional antigen-presenting cells and their prominent presence around damaged bile ducts of PBC patients are documented. cDC1 is a rare subset of DC known for its cross-presentation abilities and interleukin 12 production. Our aim was to assess the role of cDC1 in the pathogenesis of PBC. We utilized an inducible murine model of PBC and took advantage of the DC reporter mice Zbtb46gfp and the Batf3-/- mice that specifically lack the cDC1 subset. cDC1 cells were sorted from blood of PBC patients and healthy individuals and subjected to Bulk-MARS-seq transcriptome analysis. Histopathology assessment demonstrated peri-portal inflammation in wild type (WT) mice, whereas only minor abnormalities were observed in Batf3-/- mice. Flow cytometry analysis revealed a two-fold reduction in hepatic CD8/CD4 T cells ratio in Batf3-/- mice, suggesting reduced intrahepatic CD8 T cells expansion. Histological evidence of portal fibrosis was detected only in the WT but not in Batf3-/- mice. This finding was supported by decreased expression levels of pro-fibrotic genes in the livers of Batf3-/- mice. Transcriptome analysis of human cDC1, revealed 78 differentially expressed genes between PBC patients and controls. Genes related to antigen presentation, TNF and IFN signalling and mitochondrial dysfunction were significantly increased in cDC1 isolated from PBC patients. Our data illustrated the contribution the cDC1 subset in the pathogenesis of PBC and provides a novel direction for immune based cell-specific targeted therapeutic approach in PBC.

The Role of CCL24 in Primary Sclerosing Cholangitis: Bridging Patient Serum Proteomics to Preclinical Data.

Primary sclerosing cholangitis (PSC) is an inflammatory and fibrotic biliary disease lacking approved treatment. We studied CCL24, a chemokine shown to be overexpressed in damaged bile ducts, and its involvement in key disease-related mechanisms. Serum proteomics of PSC patients and healthy controls (HC) were analyzed using the Olink® proximity extension assay and compared based on disease presence, fibrosis severity, and CCL24 levels. Disease-related canonical pathways, upstream regulators, and toxicity functions were elevated in PSC patients compared to HC and further elevated in patients with high CCL24 levels. In vitro, a protein signature in CCL24-treated hepatic stellate cells (HSCs) differentiated patients by disease severity. In mice, CCL24 intraperitoneal injection selectively recruited neutrophils and monocytes. Treatment with CM-101, a CCL24-neutralizing antibody, in an α-naphthylisothiocyanate (ANIT)-induced cholestasis mouse model effectively inhibited accumulation of peribiliary neutrophils and macrophages while reducing biliary hyperplasia and fibrosis. Furthermore, in PSC patients, CCL24 levels were correlated with upregulation of monocyte and neutrophil chemotaxis pathways. Collectively, these findings highlight the distinct role of CCL24 in PSC, influencing disease-related mechanisms, affecting immune cells trafficking and HSC activation. Its blockade with CM-101 reduces inflammation and fibrosis and positions CCL24 as a promising therapeutic target in PSC.

Impact of concomitant vascular injury on the outcome of bile duct injury

Background Compared with open cholecystectomy, the frequency of iatrogenic bile duct damage (bile duct injury) has almost doubled as laparoscopic cholecystectomy (LC) has become more prevalent. The authors aimed to analyze the prevalence of postcholecystectomy vasculobiliary injury and its influence on illness and death. Methods Medical records were reviewed on 50 consecutive patients with iatrogenic bile duct injuries from either open or laparoscopic cholecystectomy who were treated at the National Liver Institute, Menoufia University between January 1, 2020 and October 31, 2022. The medical records were examined for patient demographics and preoperative and postoperative clinical scenarios, which included symptoms, operative procedures, diagnostic methods, operative repairs, length of ICU and Hospital stays, postoperative follow-up, short- and long-term complications, need for radiographic or operative revision, and patient mortality. Results The studied patients were allocated into two groups, according to presence of concomitant vascular injury; group A: cases did not develop concomitant vascular injury, group B: cases developed concomitant vascular injury. Vascular injury was significantly elevated in males than those without vascular injury (P=0.027). There were no significant variance among the studied groups as regard Hospital stay and ICU admission. There was no significant variance among the studied groups as regard short-term complications. There was a significant variance among the studied groups as regard long-term complications (P=0.003). Right lobe atrophy was significantly elevated in vascular injury cases than those without vascular injury. Conclusions Concomitant vascular injury postcholecystectomy prevalence was significantly associated with long-term complications; right lobe atrophy was significantly elevated in vascular injury cases than those without vascular injury.

Early γGT and bilirubin levels as biomarkers for regeneration and outcomes in damaged bile ducts after liver transplantation.

Early patient and allograft survival after liver transplantation (LT) depend primarily on parenchymal function, but long-term allograft success relies often on biliary-tree function. We examined parameters related to cholangiocytedamage that predict poor long-term LT outcomes after donation after brain death (DBD). Sixty bile ducts (BD)were assessed by a BD damage-score and divided into groups with "major" BD-damage (n=33) and "no relevant" damage (n=27) during static coldstorage. Patients with "major" BD damage were further investigated by measuring biliary excretion parameters in the first 14 days post-LT (followed-up for 60-months). Patients who received LT showing "major" BD damage had significantly worse long-term patient survival, versus grafts with "no relevant" damage (p=.03). When "major" BD damage developed, low bilirubin levels (p=.012) and high gamma-glutamyl transferase (GGT)/bilirubin ratio (p=.0003) were evident in the early post-LT phase (7-14 days) in patients who survived (>60 months), compared to those who did not. "High risk" patients with bile duct damage and low GGT/bilirubin ratio had significantly shorter overall survival (p<.0001). Once "major" BD damage occurs, a high GGT/bilirubin ratio in the early post-operative phase is likely indicator of liver and cholangiocyte regeneration, and thus a harbinger of good overall outcomes. "Major" BD damage without markers of regeneration identifies LT patients that could benefit from future repair therapies.

Vitamin D Receptor Activation Targets ROS-Mediated Crosstalk Between Autophagy and Apoptosis in Hepatocytes in Cholestasic Mice

Observational epidemiologic studies have associated vitamin D deficiency with cholestasis. We reported previously that activation of the vitamin D/vitamin D receptor (VDR) axis in cholangiocytes mitigates cholestatic liver injury by remodeling the damaged bile duct. However, the function of VDR in hepatocytes during cholestasis remains unclear. Paricalcitol (VDR agonist, 200 ng/kg) was injected intraperitoneally into bile duct-ligated mice every other day for 5 days. Primary hepatocytes and HepG2 hepatoma cells were transfected with Vdr short hairpin RNA, control short hairpin RNA, Vdr plasmid, control vector, Atg5 small interfering RNA (siRNA), and control siRNA. Liver histology, cell proliferation, and autophagy were evaluated. Treatment with the VDR agonist paricalcitol improved liver injury in bile duct-ligated mice by up-regulating VDR expression in hepatocytes, which in turn reduced hepatocyte apoptosis by inhibiting reactive oxygen species (ROS) generation via suppressing the Ras-related C3 botulinum toxin substrate 1/reduced nicotinamide adenine dinucleotide phosphate oxidase 1 pathway. Mechanistically, upon exposure to an ROS-inducing compound, Vdr siRNA contributed to apoptosis, whereas the Vdr overexpression caused resistance to apoptosis. Interestingly, up-regulated VDR expression also increased the generation of autophagosomes and macroautophagic/autophagic flux, which was the underlying mechanism for reduced apoptosis following VDR activation. Autophagy depletion impaired the positive effects of VDR overexpression, whereas autophagy induction was synergystic with VDR overexpression. Importantly, up-regulation of VDR promoted autophagy activation by suppressing the activation of the extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (p38MAPK) pathway. Thus, a p38MAPK inhibitor abrogated the Vdr siRNA-induced decrease in autophagy and the Vdr siRNA-induced increase in apoptosis. In contrast, a Mitogen-activated protein kinase kinase (MEK)/ERK activator prevented the enhancement of autophagy and decreased apoptosis following Vdr overexpression. Moreover, the ROS inhibitor N-acetylcystein (NAC) blocked Vdr siRNA-enhanced activation of the ERK/p38MAPK pathway. VDR activation mitigated liver cholestatic injury by reducing autophagy-dependent hepatocyte apoptosis and suppressing the activation of the ROS-dependent ERK/p38MAPK pathway. Thus, VDR activation may be a potential target for the treatment of cholestatic liver disease.

Biliary Epithelial Senescence in Cellular Rejection Following Live Donor Liver Transplantation

As with the hepatocytes, cholangiocyte senescence can also easily be detected in damaged small bile ducts and bile ductules during liver disease affecting the biliary system and cholangiocytes. Despite cellular senescence being a feature of chronic progressive cholangiopathies in adults, only a few studies have investigated its role in liver transplant rejection. Transplant biopsies displaying features of rejection were reviewed and classified based on the type of rejection and the time since transplantation. An immunohistochemistry panel has been applied for 3 senescent cell markers (p53, p21, p16). Immunohistochemical expression analysis for the biliary senescence markers (53 biopsies) was done in the post-transplantation periods (Group 1-4) for the cases with the histologically proven diagnosis of rejection. In post-transplant group 1 (<3 months), group 2 (3-6 months), group 3 (6-12 months) and group 4 (>12 months), any 2 senescent markers' positivity was noted in 5/14 (35.7%), 8/13 (61.5%), 16/17 (94.1%) and 9/9 (100%) biopsies respectively and were comparable in all four groups (P= 0.001). A comparison of early biopsies (Group1; 3 months) and late biopsies (Group 2,3&4; >3 months) revealed significantly higher expression in late biopsies (>3 months) (P= 0.001 for any two markers). In ACR, LAR, ECR, and CR/DR any two senescent markers were positive in 14/28 (50%), 12/13 (92.3%) cases, 9/9 (100%), and 3/3cases (100%). Senescent markers (any two) were comparable in all four histological groups (P < 0.001).LAR group had increased expression (P= 0.009 for any two markers and 0.001 for all three markers) and has increased progression to CR (P= 0.019) as compared to ACR. This study on a large number of LDLT allograft biopsies demonstrates the role of biliary senescence in rejection and suggests a pathobiological role for senescence in the poor prognosis seen in late acute cellular rejection and chronic rejection.

Hydrogels derived from decellularized liver tissue support the growth and differentiation of cholangiocyte organoids

Human cholangiocyte organoids are promising for regenerative medicine applications, such as repair of damaged bile ducts. However, organoids are typically cultured in mouse tumor-derived basement membrane extracts (BME), which is poorly defined, highly variable and limits the direct clinical applications of organoids in patients. Extracellular matrix (ECM)-derived hydrogels prepared from decellularized human or porcine livers are attractive alternative culture substrates. Here, the culture and expansion of human cholangiocyte organoids in liver ECM(LECM)-derived hydrogels is described. These hydrogels support proliferation of cholangiocyte organoids and maintain the cholangiocyte-like phenotype. The use of LECM hydrogels does not significantly alter the expression of selected genes or proteins, such as the cholangiocyte marker cytokeratin-7, and no species-specific effect is found between human or porcine LECM hydrogels. Proliferation rates of organoids cultured in LECM hydrogels are lower, but the differentiation capacity of the cholangiocyte organoids towards hepatocyte-like cells is not altered by the presence of tissue-specific ECM components. Moreover, human LECM extracts support the expansion of ICO in a dynamic culture set up without the need for laborious static culture of organoids in hydrogel domes. Liver ECM hydrogels can successfully replace tumor-derived BME and can potentially unlock the full clinical potential of human cholangiocyte organoids.

Preparation of Tubular Biocellulose Implants and Its Use in Surgery—A Review

This review highlights the current state regarding the preparation and characterization of tubular biocellulose materials as well as their application and application potential with a special focus on abdominal oncologic surgery. Biocellulose is a natural polymer synthesized by acetic acid bacteria from low molecular sugars and alcohols as a mechanically stable nanofiber network at the interface between the aqueous culture medium and air. This hydrogel is characterized by very high purity and biocompatibility, dimensional stability, and good surgical handling. With this property profile, biocellulose proves to be a promising candidate for the development of novel medical soft tissue implants. This requires close R&amp;D cooperation between chemists, material scientists, biotechnologists, and surgeons. In this sense, this review spans from the natural polymer to the design of biocellulose implants and surgical suitability. It is also a concern of this article to show concretely the great need for such implants and the fields of application in oncological abdominal surgery where tubular biocellulose is or could be the focus of research. Furthermore, a critical assessment for the use of biocellulose materials concerning incidence malignancy and surgical interventions, complication rates, and current studies is emphasized. The regeneration of damaged bile ducts by the use of biocellulose implants is a first example.

S2724 Clinical Presentation, Treatment Strategies, and Chronic Sequelae of Immune Checkpoint Inhibitor-Mediated Cholangiopathy: A Case Study

Introduction: Immunotherapy-mediated cholangiopathy (IMCp) is an under-recognized phenotype of immunotherapy-mediated hepatobiliary toxicity (IMH) with specific consequences. IMCp cases bear a risk of the need for treatment escalation beyond corticosteroids alone, and the long-term sequelae are not well documented. We describe a case of steroid-refractory IMCp successfully treated with tocilizumab and ursodiol. Case Description/Methods: A 56-year-old man, treated with ipilimumab and nivolumab for metastatic lung squamous cell carcinoma, presented with abnormal liver enzymes attributed to toxicity secondary to immune checkpoint inhibitors. The initial peak ALT was 273 U/L, with AST 128 U/L, alkaline phosphatase (ALP) 590 U/L, GGT 938 U/L, and total bilirubin 2.0 mg/dL; R factor was < 2, suggesting a cholestatic-predominant pattern of injury. Oral prednisone 60 mg/d and ursodiol yielded only partial improvement; prednisone dose was increased to 80 mg/d, and azathioprine (AZA) 50 mg/d was added. Liver biopsy confirmed histologic bile duct injury; abdominal MRI showed enhancement of the left, right, and common hepatic ducts. ALT increased to >350 U/L with total bilirubin to 2.4 mg/dL despite intravenous (IV) methylprednisolone 160 mg/d. IV tocilizumab (TCZ) 8 mg/kg was administered, allowing for tapering off of prednisone, while continuing ursodiol and AZA. ALT improved from 519 to 82 after 44 days, and another infusion of IV TCZ at 4 mg/kg was given. The ALT improved and remained stable in 40-50 range for another 5 months. The ALP approached a nadir of 160 and eventually settled between 300-400. After ursodiol and AZA were discontinued, brief increases were seen of ALT to 106, AST to 82, ALP to 574, and GGT to 1283, which improved to baseline after ursodiol was resumed. Nine months after initial diagnosis, MRI showed persistent intrahepatic biliary ductal dilation with normal common hepatic duct and common bile duct. Patient was doing clinically well. Discussion: In this case of relapsing and steroid-refractory IMCp, with intrahepatic sclerosing cholangitis, tocilizumab, an IL-6 receptor antagonist, yielded successful biochemical and clinical remission, allowing discontinuation of prednisone, despite persistent intrahepatic biliary dilatation. Ursodiol as an adjunct may also play a crucial role in treating IMCp to manage cholestasis and as maintenance therapy. Longitudinal studies are needed to determine if permanent biliary sequelae may occur and whether these features pose practical clinical consequences.Figure 1.: (A) Liver biopsy (H&E, 200x) histology demonstrating expansion of the portal tracts by inflammation which is centered on the damaged bile duct. (B) Abdominal MRI/MRCP showing enhancement of the intrahepatic biliary tree; some of the right intrahepatic ducts demonstrate new beaded appearance; related findings were interpreted as progressive when compared to a prior MRI/MRCP. (C) Chronological clinical course trending liver biochemistries in relation to treatments employed before and after development of immune checkpoint inhibitor-mediated cholangiopathy. (Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; GGT, gamma-glutamyl transferase; Nivo, nivolumab; Pred, prednisone; UDCA, ursodeoxycholic acid or ursodiol; AZA, azathioprine; IV, intravenous; methylpred, methylprednisolone).

S2905 Prolonged Cholestasis After COVID-19

Introduction: The coronavirus SARS-CoV-2 (COVID-19) is known to cause both pulmonary and hepatic injury. Cholangiocytes have an abundance of angiotensin-converting enzyme 2 receptors, which are the main mode of entry for the virus. Whether the liver injury is caused directly by the virus or as a result of the cytokine storm remains unknown. We present a case of prolonged cholestatic liver injury secondary to COVID-19. Case Description/Methods: A 55-year-old woman presented to our institution with sudden onset of right leg pain and swelling. She had hypertension, diabetes, obesity, and hypothyroidism. She denied any history of liver disease, toxic habits and was not taking any hepatotoxic medications or supplements. Two months prior to presentation, she was admitted to another hospital with severe COVID-19 pneumonia requiring mechanical ventilation. She had received Remdesivir, Convalescent Plasma, Extra Corporeal Membrane Oxygenation (ECMO), and hemodialysis for acute renal failure, before being discharged. During this admission, she was found to have a right lower extremity thrombus and was started on Enoxaparin. Her liver function tests were significant for a markedly elevated alkaline phosphatase level. An ultrasound abdomen was significant only for a fatty liver. CT scan of the abdomen with contrast and an MRCP did not reveal any hepatobiliary abnormalities. Viral hepatitis serology and autoimmune workup were negative. She underwent a liver biopsy which demonstrated cholestasis, mild lobular necroinflammation, and macrovesicular steatosis. There was no PCR evidence of SARS-CoV-2. Her hospital course was complicated by MRSA and pseudomonas pneumonia. She suffered a cardiac arrest and ultimately succumbed to her infection 2 months later. Her Alkaline phosphatase remained elevated throughout her hospital stay. Discussion: Although our patient’s liver biopsy did not demonstrate PCR evidence of SARS-COV-2, it was consistent with histological features of COVID-19 related hepatic injury. Macrovesicular steatosis is the most common histological finding, followed by lobular necroinflammation, according to a case series of 40 patients who died of COVID-19. PCR for SARS-COV-2 in liver biopsy was positive in only 55% of patients. Recent reports have identified ECMO as a cause of secondary sclerosing cholangitis in critically ill patients, which remains a possibility in our case. However, a normal bilirubin level and MRCP did not support this diagnosis in our patient.Figure 1.: (A) 4 x magnification, (B) 10 x magnification, and (C) 40 x magnification of a liver biopsy specimen demonstrating hepatocellular cholestasis with feathery degeneration of hepatocytes, mild lobular neuroinflammation, and mild macrovesicular steatosis. There is sinusoidal dilatation and glycogenated nuclei. Portal tracts show mild to moderate mixed cellular infiltration, including eosinophils, endothelilitis, ductular reaction, and focal mild bile duct damage. There is no pericellular fibrosis to indicate non-alcoholic chronic steatohepatitis, although rare perivenular ballooned hepatocytes are noted on the H&E slide. CK7 immunostain shows moderate to marked ductular reaction, rare cholestatic hepatocytes, and damaged bile ducts. Findings are those of subacute cholestatic hepatitis.Table 1.: Laboratory values from the previous hospitalization, on admission day of this hospitalization, at 1-month of hospitalization, and prior to death.

Paricalcitol inhibits oxidative stress-induced cell senescence of the bile duct epithelium dependent on modulating Sirt1 pathway in cholestatic mice

BackgroundClinical studies indicate that vitamin D receptor (VDR) expression is reduced in primary biliary cirrhosis patient livers. However, the mechanism by which activated VDR effect cholestatic liver injury remains unclear. MethodsMice were injected intraperitoneally with the VDR agonist paricalcitol or a vehicle 3 days prior to bile duct ligation (BDL) and for 5 or 28 days after surgery. The analyses of liver morphology and necrotic areas were based on H&E staining. Serum biochemical indicators of liver damage were analyzed by commercial kits. The mechanisms of paricalcitol on cholestatic liver injury were determined by Western blot analysis. ResultsParicalcitol ameliorated the BDL-induced liver damage in mice. Paricalcitol increased the proliferation of BECs to promote the repair of the bile duct. Paricalcitol also reduced the BDL-induced oxidative stress level in the mice. Mechanistic analysis revealed that paricalcitol decreased the number of SA-β-gal-positive cells and downregulated the expression of p53, p21 and p16 proteins which was associated with reducing oxidative stress. Additionally, paricalcitol exerted the inhibitory effect of cell senescence was through reducing DNA damage and promoting DNA repair. Interesting, we found that paricalcitol prevented the downregulation of oxidative stress-induced Sirt1 expression in the BDL mice and t-BHP-induced BECs models. Moreover, paricalcitol suppressed cell senescence through a Sirt1-dependent pathway. These results were confirmed by antioxidant ALCAR and the Sirt1 inhibitor EX-527. ConclusionParicalcitol alleviated cholestatic liver injury through promoting the repair of damaged bile ducts and reducing oxidative stress-induced cell senescence of the bile duct via modulating Sirt1 pathway.

Pathological Study of Facial Eczema (Pithomycotoxicosis) in Sheep.

Simple SummaryFacial eczema (FE) is a secondary photosensitization disease of farm ruminants caused by the sporidesmin A, present in the spores of the saprophytic fungus Pithomyces chartarum. This study communicates an outbreak of ovine FE in Asturias (Spain) and characterizes the local immune response that may contribute to liver damage promoting cholestasis and progression towards fibrosis and cirrhosis. Animals showed clinical signs of photosensitivity and lower gain of weight, loss of wool and crusting in the head for at least 6 months after the FE outbreak. Some sheep presented acute lesions characterized by subcutaneous edema in the head, cholestasis and nephrosis with macrophages and neutrophils present in areas of canalicular cholestasis. In chronic cases, alopecia and crusting, hepatic atrophy with regenerative nodules, fibrosis and gallstones were seen. The surviving parenchyma persisted with a jigsaw pattern characteristic of biliary cirrhosis. Concentric and eccentric myointimal proliferation was found in arteries near damaged bile ducts, where macrophages and lymphocytes were also observed. Facial eczema (FE) is a secondary photosensitization disease of farm ruminants caused by the sporidesmin A, produced in the spores of the saprophytic fungus Pithomyces chartarum. This study communicates an outbreak of ovine FE in Asturias (Spain) and characterizes the serum biochemical pattern and the immune response that may contribute to liver damage, favoring cholestasis and the progression to fibrosis and cirrhosis. Animals showed clinical signs of photosensitivity, with decrease of daily weight gain and loss of wool and crusting for at least 6 months after the FE outbreak. Serum activity of γ-glutamyltransferase and alkaline phosphatase were significantly increased in sheep with skin lesions. In the acute phase, edematous skin lesions in the head, hepatocytic and canalicular cholestasis in centrilobular regions, presence of neutrophils in small clumps surrounding deposits of bile pigment, ductular proliferation, as well as cholemic nephrosis, were observed. Macrophages, stained positively for MAC387, were found in areas of canalicular cholestasis. In the chronic phase, areas of alopecia and crusting were seen in the head, and the liver was atrophic with large regeneration nodules and gallstones. Fibrosis around dilated bile ducts, “typical” and “atypical” ductular reaction and an inflammatory infiltrate composed of lymphocytes and pigmented macrophages, with iron deposits and lipofuscin, were found. The surviving parenchyma persisted with a jigsaw pattern characteristic of biliary cirrhosis. Concentric and eccentric myointimal proliferation was found in arteries near damaged bile ducts. In cirrhotic livers, stellated cells, ductular reaction, ectatic bile ducts and presence of M2 macrophages and lymphocytes, were observed in areas of bile ductular reaction.

Scaffolds obtained from decellularized human extrahepatic bile ducts support organoids to establish functional biliary tissue in a dish.

Biliary disorders can lead to life‐threatening disease and are also a challenging complication of liver transplantation. As there are limited treatment options, tissue engineered bile ducts could be employed to replace or repair damaged bile ducts. We explored how these constructs can be created by seeding hepatobiliary LGR5+ organoids onto tissue‐specific scaffold. For this, we decellularized discarded human extrahepatic bile ducts (EBD) that we recellularized with organoids of different origin, that is, liver biopsies, extrahepatic bile duct biopsies, and bile samples. Here, we demonstrate efficient decellularization of EBD tissue. Recellularization of the EBD extracellular matrix (ECM) with the organoids of extrahepatic origin (EBD tissue and bile derived organoids) showed more profound repopulation of the ductal ECM when compared with liver tissue (intrahepatic bile duct) derived organoids. The bile duct constructs that were repopulated with extrahepatic organoids expressed mature cholangiocyte‐markers and had increased electrical resistance, indicating restoration of the barrier function. Therefore, the organoids of extrahepatic sources are identified to be the optimal candidate for the development of personalized tissue engineered EBD constructs.

Secondary cholangitis of the critically ill

Sclerosing Cholangitis of the Critically Ill (SC-CIP) is a relatively new entity within the spectrum of secondary cholangitis that develops in the wake of intensive care therapy with mechanical ventilation and catecholamine treatment. It is caused by ischemic or immunologic injury to small bile ducts that becomes self-aggravating and persists beyond the end of the intensive care stay. Early clinical and laboratory findings show acute cholangitis with elevated CRP, gamma GT, AP, and bilirubin. ERCP shows damaged intrahepatic bile ducts with irregular calibers and biliary casts. The following phase is chronic and oligosymptomatic. Still, all laboratory parameters will stay mildly elevated and ERCP and MRCP will show progressive loss of small bile ducts. Long-term prognosis is poor. Even with UDCA therapy, most patients will develop liver cirrhosis within months or years.

Isolation and propagation of primary human cholangiocyte organoids for the generation of bioengineered biliary tissue.

Pediatric liver transplantation is often required as a consequence of biliary disorders because of the lack of alternative treatments for repairing or replacing damaged bile ducts. To address the lack of availability of pediatric livers suitable for transplantation, we developed a protocol for generating bioengineered biliary tissue suitable for biliary reconstruction. Our platform allows the derivation of cholangiocyte organoids (COs) expressing key biliary markers and retaining functions of primary extra- or intrahepatic duct cholangiocytes within 2 weeks of isolation. COs are subsequently seeded on polyglycolic acid (PGA) scaffolds or densified collagen constructs for 4 weeks to generate bioengineered tissue retaining biliary characteristics. Expertise in organoid culture and tissue engineering is desirable for optimal results. COs correspond to mature functional cholangiocytes, differentiating our method from alternative organoid systems currently available that propagate adult stem cells. Consequently, COs provide a unique platform for studies in biliary physiology and pathophysiology, and the resulting bioengineered tissue has broad applications for regenerative medicine and cholangiopathies.

Current therapies and novel approaches for biliary diseases.

Chronic liver diseases that inevitably lead to hepatic fibrosis, cirrhosis and/or hepatocellular carcinoma have become a major cause of illness and death worldwide. Among them, cholangiopathies or cholestatic liver diseases comprise a large group of conditions in which injury is primarily focused on the biliary system. These include congenital diseases (such as biliary atresia and cystic fibrosis), acquired diseases (such as primary sclerosing cholangitis and primary biliary cirrhosis), and those that arise from secondary damage to the biliary tree from obstruction, cholangitis or ischaemia. These conditions are associated with a specific pattern of chronic liver injury centered on damaged bile ducts that drive the development of peribiliary fibrosis and, ultimately, biliary cirrhosis and liver failure. For most, there is no established medical therapy and, hence, these diseases remain one of the most important indications for liver transplantation. As a result, there is a major need to develop new therapies that can prevent the development of chronic biliary injury and fibrosis. This mini-review briefly discusses the pathophysiology of liver fibrosis and its progression to cirrhosis. We make a special emphasis on biliary fibrosis and current therapeutic options, such as angiotensin converting enzyme-2 (known as ACE2) over-expression in the diseased liver as a novel potential therapy to treat this condition.

Histopathologic Approach to Cholestatic Diseases of the Liver

Abstract Liver biopsy specimens of patients with cholestatic diseases pose a challenge to pathologists since, in most instances, this procedure is performed in a selected group of patients in whom clinical, laboratory, and imaging studies are inconclusive. Proper interpretation of the various histologic features is facilitated by the recognition of the most common patterns, which correlate with a defined group of diseases. Cholestatic disorders are grouped in 2 broad categories: acute and chronic. Four histologic patterns with different clinical implication are recognized within the first category: (1) ductular reaction, (2) pure canalicular cholestasis, (3) cholestasis with intrahepatic bile duct disease, and (4) cholestatic hepatitis. Chronic disorders are recognized by portal-based fibrosis, Mallory-Denk bodies, cholate stasis, accumulation of copper or copper-binding proteins, and biliary-type cirrhosis. Immunohistochemical reactions for cytokeratin 7 help to identify damaged bile ducts, highlight reactive ductules, and, most importantly, provide support for a cholestatic disorder by the staining of periportal hepatocytes (intermediate phenotype). The histologic features of primary biliary cholangitis and primary sclerosing cholangitis are reviewed with special emphasis on overlap syndromes and other entities that enter in the differential diagnosis.

Successful Treatment of Fibrosing Cholestatic Hepatitis C With Sofosbuvir and Simeprevir

Case Report: A 62-year-old female with HCV (GT 1a, nonresponder to pegylated interferon-alfa [PEG] and ribavirin [RBV]) who had been doing well on tacrolimus and mycophenolate presented with jaundice 3 years after liver transplantation (LT). Labs were significant for AST 391 u/L, ALT 324 u/L, AP 184 u/L, TB 1.3 mg/dL, and DB 0.4 mg/dL. An ultrasound showed a patent portal vein and hepatic artery. A liver biopsy showed moderate acute cellular rejection (ACR), also with cholestasis and portal fibrosis. The patient was treated with 3 doses of methylprednisolone 500 mg IV followed by a prednisone taper. Repeat liver biopsies 12 and 26 days later were interpreted as resolving ACR, but still showed moderate cholestasis, raising concern for fibrosing cholestatic HCV (FCH). Labs showed AST 193, ALT 334, AP 334, GGT 1054 u/L, TB 19.7, DB 11.4, HCV RNA 4,009,783 IU/mL. PCR for CMV and EBV was negative. When the patient’s labs worsened with a TB of 39.1 and HCV RNA 1,076,167 IU/mL after a second course of methylprednisolone, a fourth liver biopsy done 7 weeks after initial presentation revealed marked cholestasis, numerous damaged bile ducts, mixed inflammation, and stage 2 fibrosis. FCH could not be ruled out histologically, and clinical suspicion was high, thus treatment was begun with a combination of sofosbuvir (SOF), simeprevir (SIM), and RBV. The patient’s liver tests markedly improved and after 6 weeks; her HCV RNA level was undetectable. RBV was discontinued at week 6 due to anemia. The patient is doing well at week 16 with normalization of her labs (Figure 1), with a plan to complete a 24-week course of SOF/SIM.Figure 1Discussion: FCH is an aggressive form of HCV that can occur in up to 14% of patients transplanted for HCV, and can lead to graft loss and death. Differentiating FCH from ACR can be challenging, and can lead to a delay in diagnosis. Treatment of presumptive ACR with high-dose steroids can exacerbate FCH. With the advent of safer and more effective HCV regimens, the histologic criteria for FCH may need to be broadened in order to identify patients who may benefit from earlier HCV treatment.