Biliary atresia in children (analytical literature review and review of own observation).

OBJECTIVE: Aim: to review information resources and analysis of the own experience on this problem for the provision of modern knowledge in the pathogenesis of the pathology, the latest diagnostic and treatment technologies, with consideration of the need to adhere to a single strategy in the management of patients with BA. PATIENTS AND METHODS: Materials and Methods: The analysis of the data regarding the results of existing studies evaluating the clinical benefit and safety of diagnostic and treatment methods in Biliary atresia. CONCLUSION: Conclusions: BA is the leading cause of neonatal cholestasis development. Early diagnostics of BA, based on the complex evaluation of clinical-laboratory, instrumental and morphological signs of the pathology, has a significant meaning. Surgical correction during the first 2 months of life - the Kasai procedure, as well as dynamic post-surgery follow-up significantly prolong the life of children and allow postponing liver transplantation. The highest patient survival both at the first stage of treatment - conduction of the Kasai procedure and the stage of liver transplantation may be achieved by joined work of surgeons and pediatricians, which allows considering the whole row of possible problems.

Mucosal-associated invariant T cells promote ductular reaction through amphiregulin in biliary atresia.

BACKGROUND: Biliary atresia (BA) is a neonatal fibro-inflammatory cholangiopathy with ductular reaction as a key pathogenic feature predicting poor survival. Mucosal-associated invariant T (MAIT) cells are enriched in human liver and display multiple roles in liver diseases. We aimed to investigate the function of MAIT cells in BA. METHODS: First, we analyzed correlations between liver MAIT cell and clinical parameters (survival, alanine transaminase, bilirubin, histological inflammation and fibrosis) in two public cohorts of patients with BA (US and China). Kaplan-Meier survival analysis and spearman correlation analysis were employed for survival data and other clinical parameters, respectively. Next, we obtained liver samples or peripheral blood from BA and control patients for bulk RNA sequencing, flow cytometry analysis, immunostaning and functional experiments of MAIT cells. Finally, we established two in vitro co-culture systems, one is the rhesus rotavirus (RRV) infected co-culture system to model immune dysfunction of human BA which was validated by single cell RNA sequencing and the other is a multicellular system composed of biliary organoids, LX-2 and MAIT cells to evaluate the role of MAIT cells on ductular reaction. FINDINGS: Liver MAIT cells in BA were positively associated with low survival and ductular reaction. Moreover, liver MAIT cells were activated, exhibited a wound healing signature and highly expressed growth factor Amphiregulin (AREG) in a T cell receptor (TCR)-dependent manner. Antagonism of AREG abrogated the proliferative effect of BA MAIT cells on both cholangiocytes and biliary organoids. A RRV infected co-culture system, recapitulated immune dysfunction of human BA, disclosed that RRV-primed MAIT cells promoted cholangiocyte proliferation via AREG, and further induced inflammation and fibrosis in the multicellular system. INTERPRETATION: MAIT cells exhibit a wound healing signature depending on TCR signaling and promote ductular reaction via AREG, which is associated with advanced fibrosis and predictive of low survival in BA. FUNDING: This work was funded by National Natural Science Foundation of China grant (82001589 and 92168108), National Key R&D Program of China (2023YFA1801600) and by Basic and Applied Basic Research Foundation of Guangdong (2020A1515110921).

Pkd1l1-deficiency drives biliary atresia through ciliary dysfunction in biliary epithelial cells.

BACKGROUND & AIMS: Syndromic biliary atresia is a cholangiopathy characterized by fibro-obliterative changes in the extrahepatic bile duct (EHBD) and congenital malformations including laterality defects. The etiology remains elusive and faithful animal models are lacking. Genetic syndromes provide important clues regarding the pathogenic mechanisms underlying the disease. We investigated the role of the gene Pkd1l1 in the pathophysiology of syndromic biliary atresia. METHODS: Constitutive and conditional Pkd1l1 knockout mice were generated to explore genetic pathology as a cause of syndromic biliary atresia. We investigated congenital malformations, EHBD and liver pathology, EHBD gene expression, and biliary epithelial cell turnover. Biliary drainage was functionally assessed with cholangiography. Histology and serum chemistries were assessed after DDC (3,5-diethoxycarbony l-1,4-dihydrocollidine) diet treatment and inhibition of the ciliary signaling effector GLI1. RESULTS: Pkd1l1-deficient mice exhibited congenital anomalies including malrotation and heterotaxy. Pkd1l1-deficient EHBDs were hypertrophic and fibrotic. Pkd1l1-deficient EHBDs were patent but displayed delayed biliary drainage. Pkd1l1-deficient livers exhibited ductular reaction and periportal fibrosis. After DDC treatment, Pkd1l1-deficient mice exhibited EHBD obstruction and advanced liver fibrosis. Pkd1l1-deficient mice had increased expression of fibrosis and extracellular matrix remodeling genes (Tgfα, Cdkn1a, Hb-egf, Fgfr3, Pdgfc, Mmp12, and Mmp15) and decreased expression of genes mediating ciliary signaling (Gli1, Gli2, Ptch1, and Ptch2). Primary cilia were reduced on biliary epithelial cells and altered expression of ciliogenesis genes occurred in Pkd1l1-deficient mice. Small molecule inhibition of the ciliary signaling effector GLI1 with Gant61 recapitulated Pkd1l1-deficiency. CONCLUSIONS: Pkd1l1 loss causes both laterality defects and fibro-proliferative EHBD transformation through disrupted ciliary signaling, phenocopying syndromic biliary atresia. Pkd1l1-deficient mice function as an authentic genetic model for study of the pathogenesis of biliary atresia. IMPACT AND IMPLICATIONS: The syndromic form of biliary atresia is characterized by fibro-obliteration of extrahepatic bile ducts and is often accompanied by laterality defects. The etiology is unknown, but Pkd1l1 was identified as a potential genetic candidate for syndromic biliary atresia. We found that loss of the ciliary gene Pkd1l1 contributes to hepatobiliary pathology in biliary atresia, exhibited by bile duct hypertrophy, reduced biliary drainage, and liver fibrosis in Pkd1l1-deficient mice. Pkd1l1-deficient mice serve as a genetic model of biliary atresia and reveal ciliopathy as an etiology of biliary atresia. This model will help scientists uncover new therapeutic approaches for patients with biliary atresia, while pediatric hepatologists should validate the diagnostic utility of PKD1L1 variants.

Neurotensin contributes to cholestatic liver disease potentially modulating matrix metalloprotease-7.

The diagnosis and treatment of biliary atresia pose challenges due to the absence of reliable biomarkers and limited understanding of its etiology. The plasma and liver of patients with biliary atresia exhibit elevated levels of neurotensin. To investigate the specific role of neurotensin in the progression of biliary atresia, the patient's liver pathological section was employed. Biliary organoids, cultured biliary cells, and a mouse model were employed to elucidate both the potential diagnostic significance of neurotensin and its underlying mechanistic pathway. In patients' blood, the levels of neurotensin were positively correlated with matrix metalloprotease-7, interleukin-8, and liver function enzymes. Neurotensin and neurotensin receptors were mainly expressed in the intrahepatic biliary cells and were stimulated by bile acids. Neurotensin suppressed the growth and increased expression of matrix metalloprotease-7 in biliary organoids. Neurotensin inhibited mitochondrial respiration, oxidative phosphorylation, and attenuated the activation of calmodulin-dependent kinase kinase 2-adenosine monophosphate-activated protein kinase (CaMKK2-AMPK) signaling in cultured biliary cells. The stimulation of neurotensin in mice and cultured cholangiocytes resulted in the upregulation of matrix metalloprotease-7 expression through binding to its receptors, namely neurotensin receptors 1/3, thereby attenuating the activation of the CaMKK2-AMPK pathway. In conclusion, these findings revealed the changes of neurotensin in patients with cholestatic liver disease and its mechanism in the progression of the disease, providing a new understanding of the complex mechanism of hepatobiliary injury in children with biliary atresia.

Intrahepatic Cholangiolitis in Cystic Fibrosis (ICCF): An Under-Appreciated Cause of Persistent Cholestasis in Infancy.

Liver histology in infants with cystic fibrosis (CF) and persistent cholestasis is seldom reported in detail. We extend previous observation of a distinctive intrahepatic cholangiopathy (ICCF) to 3 additional infants homozygous for CFTR pathological variants and a fourth infant with a heterozygous CFTR variant, summarizing our experience in 10 infants with CFTR variants and persistent cholestasis. Cholangiograms demonstrate abnormal extrahepatic ducts in 2 infants with CF, 1 with uniform dilatation interpreted as a choledochal cyst and the other with narrow patent ducts. Liver histology in 3 CF homozygotes had prominent ductular reaction with a focally destructive cholangiolitis (inflammation of small bile ducts). The CFTR heterozygote had generalized portal edema with ductular reaction and paucity but no cholangitis. Cholestasis slowly subsided in all infants. ICCF is characterized by severe ductular reaction, prominent cholangiocyte injury, and multifocal necrotizing cholangiolitis. Local aggregates of portal ceroid might suggest previous bile leakage from damaged ducts. ICCF in liver biopsies from infants with cystic fibrosis and persistent cholestasis is unrelated to the specific CFTR genotype. Liver biopsy findings and intraoperative cholangiogram help rule out biliary atresia. ICCF is an early manifestation of CF, a likely prototype for pathogenesis of cystic fibrosis liver disease later in life.

Pathologic approach to Neonatal cholestasis with a simple scoring system for biliary atresia.

A liver biopsy is essential for the diagnostic workup of persistent neonatal cholestasis (NC). The differential diagnosis of NC is broad, including obstructive and non-obstructive causes. In addition, histologic features of certain disorders may be non-specific in the early course of the disease. To evaluate liver biopsies using a practical histopathologic approach for NC and to define a simple scoring system for biliary atresia (BA) for routine clinical practice. From June 2006 to December 2021, liver biopsy specimens from infants with persistent NC were examined by two independent pathologists. The cases diagnosed as BA were correlated with clinical, radiologic, and laboratory data to calculate the final score. Four hundred and fifty-nine cases were enrolled in the study. They had a mean age of 63.94 ± 20.62 days and were followed for a median time of 58 (1-191) months. They included 162 (35.3%) cases of BA. On multivariate analysis, portal edema, ductular proliferation, cholangiolitis, and bile duct/ductular plugs were the histopathologic predictors of BA. A liver biopsy did perform well with a 95.1% sensitivity, 91.6% specificity, 86% PPV, and 97.1% NPV. At a cutoff of 5 of the scoring system, diagnosis of BA could be done with a sensitivity of 95.1% and a specificity of 100%. We have shown detailed histopathologic features of BA with more depth to infants aged ≤ 6 weeks. We have developed a simple scoring system using a combination of liver biopsy with non-invasive methods to increase the diagnostic accuracy of BA.

Differentiating biliary atresia from other causes of infantile cholestasis: An appraisal of the histomorphological changes on liver biopsy.

Background: Cholestatic disorders are a significant cause of morbidity and mortality in infants. Characterization of these disorders and differentiating biliary atresia (BA) from other causes of intrahepatic cholestasis is an age-old problem. Objectives: To study the spectrum of different infantile cholestatic disorders in our population, to differentiate BA from other causes of neonatal cholestasis (NC) on a liver biopsy, and validation of the available scoring system for the characterization of these disorders. Materials and Methods: This is an observational cross-sectional study performed over a period of 3 years between 2018 and 2021, done on neonates and infants presenting with cholestatic jaundice. The changes on liver biopsy were evaluated by different histological parameters and available scoring systems to differentiate BA from non-BA causes. Correlation with clinical, biochemical, and imaging findings was done in all cases. Results: This study included 87 cases of NC, of which BA comprised 28 cases (32%), whereas idiopathic neonatal hepatitis (INH) comprised only 12 cases (14%). Portal neutrophilic inflammation (P = 0.000053), ductal cholestasis (P < 0.001), neoductular bile plugs (P < 0.001) and bile ductular proliferation (P < 0.0001) were significantly more in BA, whereas lobular lymphocytic inflammation (P = 0.001) and giant cell transformation of hepatocytes (P = 0.0024) were more frequent in the non-BA group. Using the Lee and Looi scoring system, a histologic score ≥7 was helpful in identifying BA with 85.7% sensitivity, 92.6% specificity, and 90.6% accuracy. Conclusion: BA is the commonest cause of NC in neonates, whereas the frequency of INH is declining. Detailed histomorphologic analysis of liver biopsy, aided with IHC, is the cornerstone for the diagnosis of these disorders.

Frequency of infiltrating regulatory T-cells in the portal tract of biliary atresia.

PURPOSE: Immunological abnormalities have been hypothesized as a pathogenesis of biliary atresia (BA). We previously investigated the frequency and function of circulating regulatory T-cells (Tregs) and reported no differences compared to controls. However, the local Treg profile remains uncertain. We aimed to investigate the frequency of Tregs in BA liver tissues. METHODS: The number of lymphocytes, CD4+ cells, and CD4+FOXP3+ Tregs infiltrating the portal tract and the percentage of Tregs among CD4+ cells of BA and control patients were visually counted. The correlation between these data and clinical indicators was also examined. RESULTS: The number of lymphocytes, CD4+ cells, and CD4+FOXP3+ Tregs was higher in the BA group. However, the percentage of Tregs among CD4+ cells was similar in both groups. Each parameter was correlated with serum γ-GTP, but there was no clear association with liver fibrosis, jaundice clearance, and native liver survival. CONCLUSION: The number of Tregs infiltrating the portal tract was higher in BA patients. However, the infiltration of lymphocytes was also generally increased. Tregs appear to be unsuccessful in suppressing progressive inflammation in BA patients, despite recruitment to local sites. Investigation of Treg function in the local environment is warranted.

Plasticity between type 2 innate lymphoid cell subsets and amphiregulin expression regulates epithelial repair in biliary atresia.

BACKGROUND AND AIMS: Although a dysregulated type 1 immune response is integral to the pathogenesis of biliary atresia, studies in both humans and mice have uncovered a type 2 response, primarily driven by type 2 innate lymphoid cells. In nonhepatic tissues, natural type 2 innate lymphoid cell (nILC2s) regulate epithelial proliferation and tissue repair, whereas inflammatory ILC2s (iIlC2s) drive tissue inflammation and injury. The aim of this study is to determine the mechanisms used by type 2 innate lymphoid cell (ILC2) subpopulations to regulate biliary epithelial response to an injury. APPROACH AND RESULTS: Using Spearman correlation analysis, nILC2 transcripts, but not those of iILC2s, are positively associated with cholangiocyte abundance in biliary atresia patients at the time of diagnosis. nILC2s are identified in the mouse liver through flow cytometry. They undergo expansion and increase amphiregulin production after IL-33 administration. This drives epithelial proliferation dependent on the IL-13/IL-4Rα/STAT6 pathway as determined by decreased nILC2s and reduced epithelial proliferation in knockout strains. The addition of IL-2 promotes inter-lineage plasticity towards a nILC2 phenotype. In experimental biliary atresia induced by rotavirus, this pathway promotes epithelial repair and tissue regeneration. The genetic loss or molecular inhibition of any part of this circuit switches nILC2s to inflammatory type 2 innate lymphoid cell-like, resulting in decreased amphiregulin production, decreased epithelial proliferation, and the full phenotype of experimental biliary atresia. CONCLUSIONS: These findings identify a key function of the IL-13/IL-4Rα/STAT6 pathway in ILC2 plasticity and an alternate circuit driven by IL-2 to promote nILC2 stability and amphiregulin expression. This pathway induces epithelial homeostasis and repair in experimental biliary atresia.

Necroptosis of macrophage is a key pathological feature in biliary atresia via GDCA/S1PR2/ZBP1/p-MLKL axis.

Biliary atresia (BA) is a severe inflammatory and fibrosing neonatal cholangiopathy disease characterized by progressive obstruction of extrahepatic bile ducts, resulting in cholestasis and progressive hepatic failure. Cholestasis may play an important role in the inflammatory and fibrotic pathological processes, but its specific mechanism is still unclear. Necroptosis mediated by Z-DNA-binding protein 1 (ZBP1)/phosphorylated-mixed lineage kinase domain-like pseudokinase (p-MLKL) is a prominent pathogenic factor in inflammatory and fibrotic diseases, but its function in BA remains unclear. Here, we aim to determine the effect of macrophage necroptosis in the BA pathology, and to explore the specific molecular mechanism. We found that necroptosis existed in BA livers, which was occurred in liver macrophages. Furthermore, this process was mediated by ZBP1/p-MLKL, and the upregulated expression of ZBP1 in BA livers was correlated with liver fibrosis and prognosis. Similarly, in the bile duct ligation (BDL) induced mouse cholestatic liver injury model, macrophage necroptosis mediated by ZBP1/p-MLKL was also observed. In vitro, conjugated bile acid-glycodeoxycholate (GDCA) upregulated ZBP1 expression in mouse bone marrow-derived monocyte/macrophages (BMDMs) through sphingosine 1-phosphate receptor 2 (S1PR2), and the induction of ZBP1 was a prerequisite for the enhanced necroptosis. Finally, after selectively knocking down of macrophage S1pr2 in vivo, ZBP1/p-MLKL-mediated necroptosis was decreased, and further collagen deposition was markedly attenuated in BDL mice. Furthermore, macrophage Zbp1 or Mlkl specific knockdown also alleviated BDL-induced liver injury/fibrosis. In conclusion, GDCA/S1PR2/ZBP1/p-MLKL mediated macrophage necroptosis plays vital role in the pathogenesis of BA liver fibrosis, and targeting this process may represent a potential therapeutic strategy for BA.

Biliary Atresia Remnants Revisited: Myogenesis, Hepatic Duct-Like Structures, and Fate of Peribiliary Glands.

PURPOSE AND CONTEXT: Proximal levels of excised remnants from youngest infants may reveal early features of biliary atresia (BA). METHOD: A targeted IHC survey was applied to 34 most proximal 2 levels in 17 BA remnants excised at age 10-74 days including 7 = <30 days old and 6 control hepatic ducts (HD). KEY RESULTS: Severity of inflammation and extent of active fibroplasia do not distinguish proximal remnants in younger (n = 7) and older (n = 10) infants. In 27/34 levels of 14/17 remnants, reactive stroma is focally SM-MHC-2 (+), marking smooth muscle myosin, termed reactive myogenesis (RM), that is absent in controls. RM facilitates identification of 3 novel hepatic duct remnants (HDR): an HD-like collagen collar lined by degenerating cholangiocytes (n = 5); erosion defects in loose reactive stroma (n = 14); solitary foci of hyperplastic squamoid epithelium (n = 4). Peribiliary glands are either hyperplastic or atretic and typically lack RM. CONCLUSION: Minimally inflammed end-stage lesions in BA remnants occur at youngest ages favoring prenatal onset. Three novel HDR are defined. RM, a useful surrogate for HDR, is a prevalent inappropriate stromal reaction in proximal remnants of uncertain biological significance. RM is the source of mature smooth muscle in BA remnants.

The accuracy of magnetic resonance cholangiopancreatography in the diagnosis of biliary atresia in preterm infants with cholestasis.

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a useful and non-invasive method to diagnose biliary atresia (BA) in term infants, however few studies have investigated its use in preterm infants. This study aimed to evaluate the accuracy of MRCP in the diagnosis of BA in preterm infants with cholestasis. METHODS: Infants aged less than 6 months who received MRCP for cholestasis at a tertiary medical center were enrolled from 2011 to 2020. Demographic and laboratory data were retrospectively obtained. One pediatric radiologist reviewed the MRCP images. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRCP to diagnose BA based on surgical proof or at least 6 months of follow-up were assessed. RESULTS: A total of 80 infants (36 preterm and 44 term) were analyzed. The mean post-chronological age was 1.8 months, and the female-to-male ratio was 0.78. Six (16.7%) preterm and 16 (36.4%) term infants were confirmed to have BA. BA was obscured by a choledochal cyst preoperatively in two term infants. In the preterm infants, the sensitivity, specificity, PPV, NPV, and accuracy of MRCP to diagnose BA were 100%, 77%, 46%, 100%, and 81%, respectively, compared to 81%, 86%, 76%, 89%, and 84% in the term infants. Using MRCP to differentiate BA from other cholestasis in the preterm infants had superior sensitivity (100% vs. 81%) and NPV (100% vs. 89%), and lower specificity (77% vs. 86%) and PPV (46% vs. 76%) than in the term infants. CONCLUSIONS: Negative MRCP findings can be used to exclude BA in preterm infants with cholestasis based on a favorable NPV.

Liver Explants of Biliary Atresia Patients Transplanted in Adulthood Show Features of Obliterative Portal Venopathy: Case Series and Guidelines for Pathologic Reporting of Adult Explants.

CONTEXT.­: Biliary atresia (BA) patients can have portal vein (PV) abnormalities. OBJECTIVE.­: To investigate the explant pathology of BA patients transplanted in adulthood with a focus on portal venous abnormalities. DESIGN.­: Adult BA liver explants were reviewed, along with prior biopsies, Kasai portoenterostomy (KP), and relevant medical records. RESULTS.­: Three explants were identified; all patients were female, with age at diagnosis, KP, and liver transplantation (LT) as follows: (1) less than 1 week, 8 days, and 25 years; (2) 15 weeks, 16 weeks, and 32 years; and (3) 7 weeks, 8 weeks, and 33 years, respectively, with normalization of conjugated bilirubin within 6 months of KP and development of portal hypertension (PHTN) within 3 years of KP for all 3. The first 2 had recurrent cholangitis. Duration of pre-LT PHTN was 22, 29, and 30 years, and that of pre-LT cholangitis was 9, 3, and 0 years, respectively. All 3 explants showed hilar and extrahepatic fibromyxoid intimal hyperplasia of the PV with parenchymal hepatoportal sclerosis. Cholestasis was limited to those with a history of cholangitis. Patient 3, without cholangitis, showed delicate septal fibrosis with peripheral accentuation without biliary cirrhosis. CONCLUSIONS.­: In the context of a functioning KP, cholestasis and biliary cirrhosis are likely related to recurrent cholangitis, which may or may not occur after KP. In the absence of biliary cirrhosis, PHTN may be secondary to obliterative venopathy. Adult BA explants should be sampled thoroughly, with a focus on hilar/perihilar connective tissue to include PV branches. Explants may not show biliary cirrhosis and should be reported with appropriate clinicopathologic correlation.

Biliary atresia & choledochal malformation--Embryological and anatomical considerations.

The two main biliary pathologies in paediatric practice, biliary atresia and choledochal malformations (CM), have their origins within prenatal life. Nevertheless, the actual mechanisms remain elusive with many unanswered questions. The extrahepatic bile duct develops as a funnel-like structure emerging from the foregut from about 3-4 weeks of gestation into the mesenchyme of the septum transversum. The cranial elements of this contain hepatoblasts - the precursors to the two key cell lines that will become hepatocytes and biliary epithelial cells. The intrahepatic bile ducts develop separately and emerge from a complex process involving the ductal plate surrounding the in-growing portal venous system from about the 7-8th week of gestation. A developmental defect at some point(s) in this process may be the cause of at least some variants of BA - the Biliary Atresia Splenic Malformation syndrome particularly - though evidence in the more common isolated BA is much more circumstantial. Similarly, some types of choledochal malformation, specifically the cystic type of CM, are invariably present during prenatal life although again an actual aetiological mechanism remains elusive.

Extrahepatic Bile Duct and Gall Bladder Dissection in Nine-Day-Old Mouse Neonates.

The dissection of murine neonatal bile ducts has been described as difficult. The main aim of the described standard operating procedure is the isolation of the extrahepatic bile duct (EBD) in mouse neonates without damaging the bile duct during preparation. Because of its exceptionally close preparation compared to the cholangiocytes cell line and harvesting of the entire extrahepatic bile duct system (EBDS), the described approach is extremely useful in researching animal models of newborn bile duct disorders, such as biliary atresia. After euthanasia, the peritoneal cavity was accessed, and the bile duct system, duodenum, and liver were extracted with the unique En-bloc-Resection (EbR). The extracted sample is placed on a foam mat, and the EBD is dissected from contaminating cells atraumatically without necessary touch. The dissection of the entire EBDS is a significant advantage of this method. Caution must be taken due to the small size and amount of bile duct tissue. Using the described technique, there is no damage to the cholangiocytes. Further, the purity of the technique is reproducible (n = 10). Therefore, optimally comparable samples can be harvested. Furthermore, no bile duct tissue is harmed, because any contact with the bile duct system can be avoided during preparation, leaving the bile fluid inside the gall bladder. Most importantly, while performing the final gall bladder and bile duct dissection, atraumatic microinstruments were used only slightly lateral of the bile duct without squeezing it. This is the key to a clean and intact sample, and essential for further histological investigation or the isolation of cholangiocytes. To summarize, the described innovative dissection technique enables especially inexperienced operators with the necessary equipment to isolate the EBDS as cleanly as possible.

Use of shear wave elastography for the diagnosis and follow-up of biliary atresia: A meta-analysis.

BACKGROUND: Timely differentiation of biliary atresia (BA) from other infantile cholestatic diseases can impact patient outcomes. Additionally, non-invasive staging of fibrosis after Kasai hepatoportoenterostomy has not been widely standardized. Shear wave elastography is an ultrasound modality that detects changes in tissue stiffness. The authors propose that the utility of elastography in BA can be elucidated through meta-analysis of existing studies. AIM: To assess the utility of elastography in: (1) BA diagnosis, and (2) post-Kasai fibrosis surveillance. METHODS: A literature search identified articles that evaluated elastography for BA diagnosis and for post-Kasai follow-up. Twenty studies met criteria for meta-analysis: Eleven for diagnosis and nine for follow-up post-Kasai. Estimated diagnostic odds ratio (DOR), sensitivity, and specificity of elastography were calculated through a random-effects model using Meta-DiSc software. RESULTS: Mean liver stiffness in BA infants at diagnosis was significantly higher than in non-BA, with overall DOR 24.61, sensitivity 83%, and specificity 79%. Post-Kasai, mean liver stiffness was significantly higher in BA patients with varices than in patients without, with DOR 16.36, sensitivity 85%, and specificity 76%. Elastography differentiated stage F4 fibrosis from F0-F3 with DOR of 70.03, sensitivity 96%, and specificity 89%. Elastography also differentiated F3-F4 fibrosis from F0-F2 with DOR of 24.68, sensitivity 85%, and specificity 81%. CONCLUSION: Elastography has potential as a non-invasive modality for BA diagnosis and surveillance post-Kasai. This paper's limitations include inter-study method heterogeneity and small sample sizes. Future, standardized, multi-center studies are recommended.

CD177+ cells produce neutrophil extracellular traps that promote biliary atresia.

BACKGROUND & AIMS: We have previously reported on the potential pathogenic role of neutrophils in biliary atresia (BA). Herein, we aimed to delineate the role of CD177+ neutrophils in the pathogenesis of BA. METHODS: Immune cells from the livers of mice with rhesus rotavirus-induced BA were analysed. Single-cell RNA-sequencing was performed to specifically analyse Gr-1+ (Ly6C/Ly6G+) cells in the liver. Gene expression profiles of CD177+ cells were analysed using the Smart-Seq RNA-sequencing method, and the pathogenesis of BA was examined in Cd177-/- mice. Neutrophil extracellular trap (NET) inhibitors were used to determine the role of CD177+ cell-derived NETs in BA-associated bile duct damage, and a pilot clinical study evaluated the potential effects of N-acetylcysteine on NET release in BA. RESULTS: Increased levels of Gr-1+ cells were observed in the livers of mice with rhesus rotavirus-induced BA. RNA-sequencing analysis revealed that CD177+ cells were the main population of Gr-1+ cells and expressed elevated levels of both interferon-stimulated and neutrophil degranulation genes. Cd177-/- BALB/c mice exhibited delayed disease onset and reduced morbidity and mortality. High numbers of mitochondria were detected in CD177+ cells derived from mice with BA; these cells were associated with increased levels of reactive oxygen species and increased NET formation, which induced the apoptosis of biliary epithelial cells in cocultures. In a pilot clinical study, the administration of N-acetylcysteine to patients with BA reduced CD177+ cell numbers and reactive oxygen species levels, indicating a potential beneficial effect. CONCLUSIONS: Our data indicate that CD177+ cells play an important role in the initiation of BA pathogenesis via NET formation. CLINICAL TRIAL REGISTRATION: The pilot study of N-acetylcysteine treatment in patients with BA was registered on the Chinese Clinical Trial Registry (ChiCTR2000040505). LAY SUMMARY: Neutrophils (a type of innate immune cell, i.e. an immune cell that doesn't target a specific antigen) are thought to play a role in the development of biliary atresia (a rare but potentially lethal condition of the bile ducts that occurs in infants). Herein, we found that neutrophils expressing a particular protein (CD177) played an important role in bile duct damage by releasing a special structure (NET) that can trap and kill pathogens but that can also cause severe tissue damage. A pilot study in patients with biliary atresia showed that inhibiting NETs could have a beneficial effect.

[A curatively resectable case of cholangiocarcinoma 52 years after cholecystoduodenostomy for biliary atresia].

A 52-year-old female had cholecystoduodenostomy for biliary atresia of type I cyst at 120 days of age. The patient's surgery recovery was uneventful;however, the patient had recurring cholangitis at the age of 27. The patient had high hepatobiliary enzymes in the outpatient clinic and was diagnosed with cholangitis. In general, the Kasai method is the mainstream for biliary atresia, since it has a much-reduced incidence of both early and late postoperative problems. However, this patient had biliary atresia of type I cyst and had undergone cholecystoduodenostomy. We suspected that the obstructive cholangitis was caused by the relatively wide anastomosis opening into the duodenal bulb, where the stomach contents pass through the most, and the poor clearance owing to the convoluted cystic duct;therefore, we chose to place a stent endoscopically. However, to our surprise, Class V was detected in the bile cytology performed as a precaution. Although no tumor was seen on imaging such as contrast-enhanced CT, EUS, and PET/CT, mapping biopsy results showed the presence of cancer at the bifurcation of the cystic duct. The patient had cholangiocarcinoma confined to the extrahepatic bile ducts only;thus, extrahepatic bile duct resection was conducted. The patient was discovered to have biliary intraepithelial neoplasia-3, and the tumor was entirely respectable. The patient had a good postoperative course, with normalization of liver function and no recurrence of cholangitis. In this case, cholangiocarcinoma was detected at an early stage by cytological examination performed as a precaution during endoscopic therapy for recurrent cholangitis. In addition to the fact that the long-term pathogenesis of biliary atresia is still unknown, it is important to note the presence of malignancy, which has the greatest effect on the patient prognosis, considering that the course of the disease varies depending on the operation carried out. Because cholecystoduodenostomy for biliary atresia is a rare approach, and there has been no previous report of related cholangiocarcinoma, we report this case for the benefit of gastroenterologists who may encounter similar cases in the future.

Characteristics of SOX9-positive progenitor-like cells during cholestatic liver regeneration in biliary atresia.

BACKGROUND: The progression of Biliary Atresia (BA) is associated with the number of reactive ductular cells (RDCs) whose heterogeneity in origin and evolution in humans remains unknown. SOX9-positive liver progenitor-like cells (LPLCs) have been shown to participate in RDCs and new hepatocyte formation during cholestatic liver regeneration in an animal model, which implies the possibility that hepatocyte-reprogrammed LPLCs could be a source of RDCs in BA. The present study aimed to elucidate the characteristics of SOX9-positive LPLCs in BA for exploring new possible therapeutic targets by manipulating the bi-differentiation process of LPLCs to prevent disease progression. METHODS: Twenty-eight patients, including 24 patients with BA and 4 patients with Congenital Choledochal Cyst as the control group, were retrospectively recruited. Liver biopsy samples were classified histologically using a 4-point scale based on fibrosis severity. LPLCs were detected by SOX9 and HNF4A double positive staining. Single immunohistochemistry, double immunohistochemistry, and multiple immunofluorescence staining were used to determine the different cell types and characteristics of LPLCs. RESULTS: The prognostic predictors of BA, namely total bile acid (TBA), RDCs, and fibrosis, were correlated to the emergence of LPLCs. SOX9 and HNF4A double-positive LPLCs co-stained rarely with relevant markers of portal hepatic progenitor cells (portal-HPCs), including CK19, CK7, EPCAM, PROM1 (CD133), TROP2, and AFP. Under cholestasis conditions, LPLCs acquired superior proliferation and anti-senescence ability among hepatocytes. Moreover, LPLCs arranged as a pseudo-rosette structure appeared from the periportal parenchyma to the portal region, which implied the differentiation from hepatocyte-reprogrammed LPLCs to RDCs with the progression of cholestasis. CONCLUSIONS: LPLCs are associated with disease progression and prognostic factors of BA. The bipotent characteristics of LPLCs are different from those of portal-HPCs. As cholestasis progresses, LPLCs appear to gain superior proliferation and anti-senescence ability and continually differentiate to RDCs.

Expression of CD56 is Not Limited to Biliary Atresia and Correlates with the Degree of Fibrosis in Pediatric Cholestatic Diseases.

BACKGROUNDS AND AIMS: CD56 immunostain is used as an adjunct to aid in the preoperative diagnosis of biliary atresia (BA) by liver biopsy. We aimed to study the expression of CD56 in different pediatric cholestatic diseases thereby evaluating its utility in the diagnosis of BA. METHODS: We performed immunohistochemistry for CD56 on 35 cases of pediatric cholestatic diseases and five age-matched controls. CD56 expression was assessed by a multiplication score (percentage positivity x intensity) in the biliary epithelium. RESULTS: The multiplication score between BA and choledochal cyst was not significantly different. High scores were also encountered in other cholestatic disorders. The score showed a significant negative association with serum albumin and a significant positive correlation with the serum ALT level. Very significant positive correlation between the score and portal fibrosis was obtained. CONCLUSION: CD56 expression is an infidel marker for the histological diagnosis of BA and rather provides a clue to the disease status in pediatric cholestatic diseases.