Design and validation of the biliary atresia research consortium histologic assessment system for cholestasis in infancy

What's new in pediatric genetic cholestatic liver disease: advances in etiology, diagnostics and therapeutic approaches

PURPOSE OF REVIEW

To highlight recent advances in pediatric cholestatic liver disease, including promising novel prognostic markers and new therapies.

FINDINGS

Additional genetic variants associated with the progressive familial intrahepatic cholestasis (PFIC) phenotype and new genetic cholangiopathies, with an emerging role of ciliopathy genes, are increasingly being identified. Genotype severity predicts outcomes in bile salt export pump (BSEP) deficiency, and post-biliary diversion serum bile acid levels significantly affect native liver survival in BSEP and progressive familial intrahepatic cholestasis type 1 (FIC1 deficiency) patients. Heterozygous variants in the MDR3 gene have been associated with various cholestatic liver disease phenotypes in adults. Ileal bile acid transporter (IBAT) inhibitors, approved for pruritus in PFIC and Alagille Syndrome (ALGS), have been associated with improved long-term quality of life and event-free survival.

SUMMARY

Next-generation sequencing (NGS) technologies have revolutionized diagnostic approaches, while discovery of new intracellular signaling pathways show promise in identifying therapeutic targets and personalized strategies. Bile acids may play a significant role in hepatic damage progression, suggesting their monitoring could guide cholestatic liver disease management. IBAT inhibitors should be incorporated early into routine management algorithms for pruritus. Data are emerging as to whether IBAT inhibitors are impacting disease biology and modifying the natural history of the cholestasis.

Biliary atresia

Biliary atresia (BA) is a progressive inflammatory fibrosclerosing disease of the biliary system and a major cause of neonatal cholestasis. It affects 1:5,000-20,000 live births, with the highest incidence in Asia. The pathogenesis is still unknown, but emerging research suggests a role for ciliary dysfunction, redox stress and hypoxia. The study of the underlying mechanisms can be conceptualized along the likely prenatal timing of an initial insult and the distinction between the injury and prenatal and postnatal responses to injury. Although still speculative, these emerging concepts, new diagnostic tools and early diagnosis might enable neoadjuvant therapy (possibly aimed at oxidative stress) before a Kasai portoenterostomy (KPE). This is particularly important, as timely KPE restores bile flow in only 50-75% of patients of whom many subsequently develop cholangitis, portal hypertension and progressive fibrosis; 60-75% of patients require liver transplantation by the age of 18 years. Early diagnosis, multidisciplinary management, centralization of surgery and optimized interventions for complications after KPE lead to better survival. Postoperative corticosteroid use has shown benefits, whereas the role of other adjuvant therapies remains to be evaluated. Continued research to better understand disease mechanisms is necessary to develop innovative treatments, including adjuvant therapies targeting the immune response, regenerative medicine approaches and new clinical tests to improve patient outcomes.

Novel Scoring Systems and Age-Based Hepatic Shear Wave Stiffness Cut-Offs for Improving Sonographic Diagnosis of Biliary Atresia

OBJECTIVES

To make sonographic evaluation for biliary atresia (BA) more objective and reproducible using scoring systems, and evaluate hepatic shear wave elastography (SWE) as an adjunct in sonographic diagnosis of BA.

METHODS

Sixty-four infants with cholestatic jaundice were enrolled between June 2016 and March 2018 in this prospective observational cohort study. Sonography and SWE was performed with SuperSonic Aixplorer system. Novel scoring systems were developed incorporating established sonographic parameters and hepatic stiffness values and analysed using SPSS software.

RESULTS

Of the 18 patients confirmed as BA, 3 were misdiagnosed on conventional sonography (16.7%) as non-BA. Gall bladder (GB) wall irregularity and fasting GB length were the most accurate (93.8%) and most specific (97.8%) individual parameters, respectively. A significant difference was noted in the triangular cord (TC) thickness of BA and non-BA infants (p <0.001), with a high specificity of 95.6% for a 4 mm cut-off value for a positive TC sign. Comparison of hepatic SWE stiffness among age-matched groups of BA and non-BA showed significant differences (≤60 d: p = 0.003; >60 d: p <0.001) but with a reduced accuracy (93.8%). Diagnostic accuracy of greyscale scoring system (96.9%), greyscale + elastography scoring system in ≤60 d (94.4%) and >60 d (97.8%) were better than that of conventional sonographic diagnosis (93.8%).

CONCLUSIONS

Grey scale scoring system improves the accuracy of sonographic diagnosis of BA without any additional cost or time penalty along with making it universally reproducible. SWE has only an adjunctive role, if any, in the sonographic diagnosis of BA.

Clinical and laboratory features of biliary atresia and patterns of management practices: Saudi national study (2000-2018)

BACKGROUND

We utilized the data from the Saudi national biliary atresia (BA) study (2000-2018) to describe the clinical, biochemical, imaging, and histopathological features of BA and the perioperative clinical practices among local pediatric gastroenterologists.

METHODS

This is a retrospective, multicenter, nationwide study that included 10 tertiary care governmental hospitals including the four liver transplant (LT) centers in different regions across Saudi Arabia.

RESULTS

BA was diagnosed in 204 infants (106 females; 10% preterm). The median age at referral was 65 days. Congenital anomalies were present in 68 patients (33%); 22 were splenic malformation (10.8%). The medians of laboratory investigations were total bilirubin (189 μmol/l), direct bilirubin (139 μmol/l), ALT (164 u/l), and GGT (472 u/l). The level of serum GGT was normal in 26 cases (12.7%). The ultrasound findings included hypoplastic or atrophic gall bladder (GB) (65%), normal GB (30%), and cord sign (5%). A HIDA scan was performed in 99 cases (48.52%). Magnetic resonance cholangiopancreatography (MRCP) was performed in 27 cases (13%). A total of 179 liver biopsies (88%) were obtained. The most common histopathologic findings were bile duct proliferation (92%), canalicular cholestasis (96%), bile plugs (84%), and portal fibrosis (95%). Cholangiography was performed in 139 cases (68%): operative in 122 (60%) and percutaneous in 17 (8%). A total of 143 children (70%) underwent Kasai portoenterostomy (KPE) at a median age of 70 days. After KPE, steroid was used in 37% of the cases and 100 cases (70%) were prescribed prophylactic antibiotics for variable duration (ranging between 3 and 12 months).

CONCLUSION

Our data show marked variation in the diagnostic evaluation and perioperative management of BA cases among the different tertiary centers. There is a need to establish a national BA registry in Saudi Arabia aiming to standardize pre- and postoperative clinical practices. Additionally, normal serum GGT level, normal GB size on ultrasound, and being a premature baby should not preclude the diagnostic workup for BA.

Pediatric Cholestatic Diseases: Common and Unique Pathogenic Mechanisms

Cholestasis is the predominate feature of many pediatric hepatobiliary diseases. The physiologic flow of bile requires multiple complex processes working in concert. Bile acid (BA) synthesis and excretion, the formation and flow of bile, and the enterohepatic reuptake of BAs all function to maintain the circulation of BAs, a key molecule in lipid digestion, metabolic and cellular signaling, and, as discussed in the review, a crucial mediator in the pathogenesis of cholestasis. Disruption of one or several of these steps can result in the accumulation of toxic BAs in bile ducts and hepatocytes leading to inflammation, fibrosis, and, over time, biliary and hepatic cirrhosis. Biliary atresia, progressive familial intrahepatic cholestasis, primary sclerosing cholangitis, and Alagille syndrome are four of the most common pediatric cholestatic conditions. Through understanding the commonalities and differences in these diseases, the important cellular mechanistic underpinnings of cholestasis can be greater appreciated.

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.

Expedited Laparoscopic Cholangiogram and Liver Biopsy in the Workup of Biliary Atresia

PURPOSE

Recent studies demonstrate the success of Kasai portoenterostomy for biliary atresia (BA) is linearly related to infant age at time of Kasai. We sought to review the feasibility and safety of laparoscopic needle micropuncture cholangiogram with concurrent core liver biopsy (if needed) for expedited exclusion of BA in patients with direct conjugated hyperbilirubinemia.

METHODS

Expedited laparoscopic cholangiogram and liver biopsy were instituted at our facility for infants with direct hyperbilirubinemia for whom clinical exam and laboratory workup failed to diagnose. A retrospective chart review was performed in infants <1 year with hyperbilirubinemia from 2016 to 2021. Demographics, preoperative evaluation, procedure details, and complications were reviewed.

RESULTS

Two hundred ninety-seven infants with unspecified jaundice were identified, of which, 86 (29%) required liver biopsy. Forty-seven percutaneous liver biopsies were obtained including 8 (17%) in whom BA could not be excluded. Laparoscopic cholangiogram was attempted in 47 infants following basic workup; BA was diagnosed in 22 infants (47%) of which 3 were <18 days old. Biliary patency was demonstrated laparoscopically in 22 of 25 (88%); 3 (12%) required conversion to open cholangiogram. Infants with percutaneous liver biopsy had an average delay of 3 days (range: 2-36) to cholangiogram. Preoperative studies and liver biopsy alone did not reliably exclude the diagnosis of BA.

CONCLUSION

Laparoscopic cholangiogram with liver biopsy is a safe procedure resulting in the confirmation or exclusion of BA in infants. Forty-seven percent of infants who underwent laparoscopic cholangiogram were found to have BA; those who were surgical candidates underwent Kasai during the same operation.

Neonatal cholestasis in children with Alpha-1-AT deficiency is a risk for earlier severe liver disease with male predominance

BACKGROUND

Our objective was to better understand the natural history and disease modifiers of Alpha-1-antitrypsin deficiency (AATD), a common genetic liver disease causing hepatitis and cirrhosis in adults and children. The clinical course is highly variable. Some infants present with neonatal cholestasis, which can resolve spontaneously or progress to cirrhosis; others are well in infancy, only to develop portal hypertension later in childhood.

METHODS

The Childhood Liver Disease Research Network has been enrolling AATD participants into longitudinal, observational studies at North American tertiary centers since 2004. We examined the clinical courses of 2 subgroups of participants from the several hundred enrolled; first, those presenting with neonatal cholestasis captured by a unique study, enrolled because of neonatal cholestasis but before specific diagnosis, then followed longitudinally (n=46); second, separately, all participants who progressed to liver transplant (n=119).

RESULTS

We found male predominance for neonatal cholestasis in AATD (65% male, p=0.04), an association of neonatal gamma-glutamyl transpeptidase elevation to more severe disease, and a higher rate of neonatal cholestasis progression to portal hypertension than previously reported (41%) occurring at median age of 5 months. Participants with and without preceding neonatal cholestasis were at risk of progression to transplant. Participants who progressed to liver transplant following neonatal cholestasis were significantly younger at transplant than those without neonatal cholestasis (4.1 vs. 7.8 years, p=0.04, overall range 0.3-17 years). Neonatal cholestasis had a negative impact on growth parameters. Coagulopathy and varices were common before transplant, but gastrointestinal bleeding was not.

CONCLUSIONS

Patients with AATD and neonatal cholestasis are at risk of early progression to severe liver disease, but the risk of severe disease extends throughout childhood. Careful attention to nutrition and growth is needed.

Does amyloid β precursor protein gene expression have a role in diagnosis of biliary atresia?

Aim of the study

Biliary atresia (BA) is an important cause of surgical jaundice. Although the precise etiology is unknown, β-amyloid (Aβ) has been observed around the bile ducts in BA livers. It is unclear whether Aβ plays a role in the pathogenesis of this disease. This study aims to assess the amyloid β precursor protein (APP) gene expression in infants with BA in comparison with other causes of neonatal cholestasis. This could help explore the role of Aβ in the pathogenesis and diagnosis of BA.

Material and methods

A prospective study was conducted at the outpatient clinic of Paediatric Hepatology, Gastroenterology, and Nutrition Department, National Liver Institute, Menoufia University, Shebin El Kom, Menoufia, Egypt during the period March 2022 to December 2022. Clinical data were gathered and laboratory and radiological investigations were conducted including β precursor protein gene expression measured in liver biopsies of the three groups using quantitative real-time PCR (qPCR).

Results

Gene expression of APP was considerably higher in the BA group (p = 0.0001) compared to neonatal cholestasis (NC) patients. Gamma glutamyl transferase (GGT) and APP had a positive correlation (p = 0.001). No significant association was found between APP and fibrosis. APP was noticeably higher in BA than NC other than BA. Also, APP in BA was higher (statistically significant, p = 0.0001) than the control. There was no statistically significant difference among NC, BA, and control groups regarding APP (p = 0.07). Both males and females did not show significant differences as regards APP (p = 0.851). Age did not have a statistically significant correlation with APP (p = 0.532). Also, there were no correlations between APP and alkaline phosphatase (ALP), aspartate transaminase (AST), or total bilirubin (TB) (p > 0.05).

Conclusions

We concluded that the development and identification of BA may depend on the liver expression of serum APP. Surgeons may be able to carry out early intraoperative cholangiography for BA confirmation if the combination of APP with GGT and other hepatic function parameters exhibits a high predictive potential as a diagnostic test for BA. To evaluate this hypothesis, more research with sizable sample numbers is necessary.

APRI and FIB-4 indices as diagnostic noninvasive scores for prediction of severe fibrosis in patients with biliary atresia

Aim of the study

Biliary atresia (BA) is a blockage in the tubes (ducts) that carry bile from the liver to the gallbladder. The aspartate aminotransferase to platelet ratio (APRI), and Fibrosis-4 (FIB-4) scores are commonly used compound surrogates for advanced fibrosis. However, the use of APRI and FIB-4 entails a risk of overestimating the fibrosis stage due to the impact of necroinflammatory activity on transaminases. So, we determined the optimal cutoff values of the APRI and FIB-4 indices in prediction of fibrosis in BA patients. The aim of the study was to evaluate the validity of the APRI and FIB-4 indices in prediction of fibrosis in patients with BA.

Material and methods

A cross sectional hospital-based study was conducted on 121 children complaining of BA attending the National Liver Institute, Menoufia University, Shebin Elkom, Menoufia, Egypt, during the period from January 2022 to February 2023.

Results

The APRI score was significantly higher among neglected BA than BA type II a, BA type III, type II b and type I (p = 0.001). Also FIB-4 was significantly higher among neglected BA than BA type II a, BA type II b, type III and type I (p = 0.001). Receiver operating characteristic (ROC) curve analysis showed that the cutoff point of the APRI score in prediction of fibrosis in patients with BA was 1.29, with sensitivity of 88.6% and specificity of 76.0%, while the cutoff point of FIB-4 in prediction of fibrosis in patients with BA was 9.82 with sensitivity of 89.0% and specificity of 70.0%.

Conclusions

Our study confirms that FIB-4 and APRI scores are both able to predict severe fibrosis. APRI score and FIB-4 are good non-invasive alternatives to liver biopsy in the detection of liver fibrosis and its extent in patients with BA.

The value of blood and urine metabolomics in differential diagnosis of cholestasis in infants

Background

Early detection of biliary atresia (BA) is a great challenge providing the main useful way to improve its clinical consequence. Promising metabolomics provides an effective method for determining innovative biomarkers and biochemical ways for improving early diagnosis. This study aimed to determine the benefit of serum and urinary potential bile acid metabolites in the differentiation of BA from non-biliary atresia (non-BA) cases using tandem mass spectrometry (MS/MS). Fourteen bile acids metabolites were measured quantitively by MS/MS in serum and urine samples from 102 cholestatic infants and 102 control infants, in addition to the assay of the total serum bile acid enzymatically.

Results

After the diagnostic clinical and laboratory workflow, cholestatic infants were divided into BA (37 infants) and non-BA (65 infants) subgroups. Remarkably on analysis of serum individual bile acid concentrations, there were significant differences between cholestatic BA and non-BA regarding serum (glycocenodeoxycholic acid (GCDCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), and GCDCA/chenodeoxycholic acid (CDCA) ratio) (p < 0.001, for all), while there was no significant difference between the two groups regarding serum level of (cholic acid (CA), glycocholic (GCA), or TCDCA/CDCA ratio). There were no significant differences in either the urinary individual bile acids or urinary primary bile acids (conjugated or unconjugated) between BA and non-BA. Further principal component analysis (PCA) analysis was done and receiver operating characteristic (ROC) analysis was performed using score plots of the positive factors in the first two principal components PC1 (CA, GCA, GCDCA, TCA, TCDCA) and PC2 (CA, CDCA, lithocholic (LCA), ursodeoxycholic acid (UDCA)) for establishing the differences between the two diseased groups and revealed that the area under the curve (AUC) for PC1 was (0.770) higher than AUC for PC2 (0.583) indicating that the positive components of PC1 may be potential biomarkers for differentiation between the two cholestatic groups.

Conclusions

Metabolomics of serum bile acid levels using tandem mass spectrometry might change the paradigm differentiating BA from non-BA saving patients from unnecessary invasive procedures.

Identification of Early Clinical and Histological Factors Predictive of Kasai Portoenterostomy Failure

Background: It is impossible to predict which patients with biliary atresia (BA) will fail after Kasai portoenterostomy (KPE). We evaluated the predictive nature of pre-KPE clinical and histological factors on transplant-free survival (TFS) and jaundice clearance. Methods: A retrospective review of patients who received a KPE at our institution (1997−2018) was performed. Primary outcomes were two-year TFS, five-year TFS, and jaundice clearance 3 months after KPE. p < 0.05 was considered significant. Results: Fifty-four patients were included in this study. The two-year TFS was 35.1%, five-year TFS was 24.5%, and 37% patients reached a direct bilirubin (DB) ≤ 2.0 mg/dL 3 months post KPE. The median age at biopsy was younger in the five-year TFS (39.0 (24.5−55.5) vs. 56.0 days (51.0−67.0), p = 0.011). Patients with DB ≤ 1.0 mg/dL 3 months after KPE were statistically younger at biopsy (DB ≤ 1.0 44.0 (26.0−56.0) vs. DB > 1.0 56.0 days (51.0−69.0), p = 0.016). Ductal plate malformation was less frequent in the five-year TFS (16/17, 94.1%, vs. 1/17, 5.9%, p = 0.037). Portal fibrosis (19/23, 82.6%, vs. 4/23, 17.4%, p = 0.028) and acute cholangitis (6/7, 85.7%, vs. 1/7, 14.3%, p = 0.047) occurred less frequently in two-year TFS. Conclusion: Older age at biopsy, acute cholangitis, portal fibrosis, and ductal plate malformation were associated with lower native liver survival. Evaluation in a larger study population is needed to validate these results.

Comparing Serum Matrix Metalloproteinase-7 in Parenteral Nutrition-Associated Liver Disease and Biliary Atresia

In this cross-sectional study, serum matrix metalloproteinase-7 levels were significantly lower in infants with jaundice and parenteral nutrition-associated liver disease compared with those with confirmed biliary atresia. Serum metalloproteinase-7 may aid in excluding biliary atresia and thus may minimize invasive testing in infants with a history of parenteral nutrition.

Identification of signature of gene expression in biliary atresia using weighted gene co-expression network analysis

Biliary atresia (BA) is the most common cause of obstructive jaundice during the neonatal period. This study aimed to identify gene expression signature in BA. The datasets were obtained from the Gene Expression Omnibus database. Weighted gene co-expression network analysis identified a critical module associated with BA, whereas Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed the functions of the essential modules. The high-connectivity genes in the most relevant module constructed protein-protein interaction networks via the string website and Cytoscape software. Hub genes screened by lasso regression consisted of a disease classification model using the randomforest method. Receiver operating characteristic curves were used to assess models' sensitivity and specificity and the model was verified using the internal and external validation sets. Ten gene modules were constructed by WGCNA, of which the brown module had a strong positive correlation with BA, comprising 443 genes. Functional enrichment analysis revealed that module genes were mainly involved in biological processes, such as extracellular matrix organization, cell adhesion, inflammatory response, and the Notch pathway (P < .001), whereas these genes were involved in the metabolic pathways and cell adhesion molecules (P < .001). Thirty-nine high-connectivity genes in the brown module constructed protein-protein interaction networks. keratin 7 (KRT7) and C-X-C motif chemokine ligand 8 (CXCL8) were used to construct a diagnostic model that had an accuracy of 93.6% and the area under the receiver operating curves for the model was 0.93. The study provided insight into the signature of gene expression and possible pathogenesis of BA; furthermore, it identified that the combination of KRT7 and CXCL8 could be a potential diagnostic model for BA.

Biliary atresia and congenital disorders of the extrahepatic bile ducts

Biliary atresia (BA) and choledochal cysts are diseases of the intrahepatic and extrahepatic biliary tree. While their exact etiopathogeneses are not known, they should be treated promptly due to the potential for irreversible parenchymal liver disease. A diagnosis of BA may be easy or complicated, but should not be delayed. BA is always treated surgically, and performing the surgery before the age of 2 mo greatly increases its effectiveness and extends the time until the need for liver transplantation arises. While the more common types of choledochal cysts require surgical treatment, some can be treated with endoscopic retrograde cholangiopancreatography. Choledochal cysts may cause recurrent cholangitis and the potential for malignancy should not be ignored.

Dynamic analysis of serum MMP-7 and its relationship with disease progression in biliary atresia: a multicenter prospective study

PURPOSE

We aimed to assess the dynamic changing trend of serum matrix metalloproteinase-7 (MMP-7) in biliary atresia (BA) patients from diagnosis to LTx to further elucidate its clinical value in diagnosis and prognoses and its relationship with disease progression.

METHODS

In this multicentre prospective study, 440 cholestasis patients (direct bilirubin level of > 17 μmol/L) were enrolled. Serum MMP-7 levels were measured using an enzyme-linked immunosorbent assay at diagnosis, 1 week, 2 weeks, 1 month, 6 weeks, 2 months, 3 months, 6 months and then every 6 months post-KPE. The medical record at each follow-up visit for post-Kasai portoenterostomy patient was collected and analyzed.

RESULTS

Using a cut-off value of > 26.73 ng/mL, serum MMP-7 had an AUC of 0.954 in BA neonates and 0.983 in BA infants. A genetic mutation (G137D) was associated with low MMP-7 levels in serum of BA patients. MMP-7 showed a mediation effect on the association between inflammation and liver fibrosis in BA patients. Four dynamic patterns of serum MMP-7 post-KPE were associated with prognosis. Serum MMP-7 was the only significant predictor at 6 weeks post-KPE and the most accurate predictor at 3 months post-KPE of survival with the native liver in 2 years.

CONCLUSION

As one of the critical factors associated with BA occurrence and progression, serum MMP-7 can be used for early diagnosis of BA and post-KPE MMP-7 level is the earliest prognostic biomarker so far.

The Value of Hepatic Scintigraphy in the Diagnosis of Biliary Atresia

Introduction

Biliary Atresia (BA) requires prompt diagnosis and surgical intervention to optimize its outcome. The aim of this study was to evaluate the accuracy of EHIDA in distinguishing between BA and other causes of cholestatic jaundice.

Methods

This was a retrospective study of all patients who underwent EHIDA in a tertiary center from 1997 to 2019. The sensitivity, specificity, Negative Predictive Value (NPV) and Positive Predictive Value (PPV) of EHIDA were evaluated. Factors that can potentially affect its accuracy were also analyzed.

Results

During the study period, 93 patients aged 10 to 110 days with cholestasis and suspected BA underwent EHIDA. The sensitivity and NPV were 91.2 and 85.3% while specificity and PPV were 80.6 and 88.1%. These results suggested that EHIDA is suboptimal in both diagnosing or excluding BA. Out of 59 patients who showed no tracer activities in the intestines after 24 h, 56 were subjected to surgical exploration and 52 (92.9%) were eventually diagnosed BA. The accuracy of EHIDA scan were different by the maturity of the patient, age at testing and severity of cholestasis.

Conclusions

EHIDA has a limited accuracy and surgical exploration remains the gold standard to establish the diagnosis of BA. Potential confounding factors that may affect the accuracy of EHIDA were identified but require further studies with larger sample sizes to validate.

Hospital Utilization, Treatment Modalities, and Mortality Using Different Biopsy Methods in Infants With Biliary Atresia

Objectives

To present a nationwide retrospective analysis of the sequelae and aftereffects of different liver biopsy methods in the care of pediatric patients with biliary atresia.

Methods

The National Inpatient Sample 2001-2013 database was queried for a primary diagnosis of biliary atresia and stratified based on biopsy type including percutaneous, surgical, laparoscopic, and transjugular. Patient demographics, length of stay, hospital costs, type of treatment, and mortality were compared by biopsy type. One-way analysis of variance test and multivariable logistic regression were used for analysis with α < 0.05.

Results

A total of 4,306 patients with biliary atresia were identified, of whom 2,293 underwent no biopsy, and 723 and 1,080 underwent a percutaneous or surgical biopsy, respectively. Significant differences in socio-demographics were demonstrated between the biopsy types. The length of stay and hospital charges were statistically significantly different between the biopsy types where patients without biopsies had the smallest length compared to percutaneous, surgical, and combination of biopsies. Overall, the Kasai procedure was done more frequently compared to direct liver transplantation, and compared to other biopsy types, undergoing a combination of biopsies had the highest odds of undergoing either procedure.

Conclusions

When comparing different biopsy methods, surgical biopsies of the liver outperformed percutaneous biopsies in hospital utilization and progression to definitive treatments with the Kasai procedure. Our research indicated that vulnerable populations such as minorities or the indigent may undergo inferior treatments or infrequently undergo definitive treatment. The need for definitive diagnostic guidelines is understated in patients with biliary atresia.

Percutaneous ultrasound-guided cholecystocholangiography with microbubbles combined with liver biopsy for the assessment of suspected biliary atresia

BACKGROUND

Percutaneous ultrasound (US)-guided cholecystocholangiography is effective in diagnosing biliary atresia for infants with a gallbladder >1.5 cm in length on US. However, whether it is still effective for other types of gallbladders needs further clarification.

OBJECTIVE

To evaluate the diagnostic performance and safety of percutaneous US-guided cholecystocholangiography combined with liver biopsy in children with suspected biliary atresia and with different types of gallbladders on US.

MATERIALS AND METHODS

Sixty-five infants were referred for percutaneous US-guided cholecystocholangiography with microbubbles and liver biopsy after an equivocal (n=39) or highly suspected (n=26) US diagnosis of biliary atresia. Two radiologists evaluated US and percutaneous US-guided cholecystocholangiography images in consensus. One pathologist independently evaluated liver specimens. We used the unpaired t-test, Mann-Whitney U test and chi-square test to analyze the data.

RESULTS

Of the 65 infants, 59 (90.8%) underwent a successful percutaneous US-guided cholecystocholangiography, with both sensitivity and specificity of 100%. All six infants for whom puncture failed had contracted gallbladders. The sensitivity and specificity of liver biopsy in the diagnosis of biliary atresia were 89.7% (26/29) and 83.3% (30/36), respectively. When percutaneous US-guided cholecystocholangiography and liver biopsy were combined, all infants gained correct diagnosis, and in 35 infants (97.2%, 35/36) biliary atresia could be excluded without intraoperative cholangiography. Twenty-two of 65 infants (33.8%) had fluid collections around the liver related to puncture. None of these complications needed treatment.

CONCLUSION

Percutaneous US-guided cholecystocholangiography combined with liver biopsy appears safe and effective for excluding or confirming biliary atresia in cholestatic infants with a dilated gallbladder on US.

Current Understanding in the Clinical Characteristics and Molecular Mechanisms in Different Subtypes of Biliary Atresia

Biliary atresia is a severe obliterative cholangiopathy in early infancy that is by far the most common cause of surgical jaundice and the most common indicator for liver transplantation in children. With the advanced knowledge gained from different clinical trials and the development of research models, a more precise clinical classification of BA (i.e., isolated BA (IBA), cystic BA (CBA), syndromic BA (SBA), and cytomegalovirus-associated BA (CMVBA)) is proposed. Different BA subtypes have similar yet distinguishable clinical manifestations. The clinical and etiological heterogeneity leads to dramatically different prognoses; hence, treatment needs to be specific. In this study, we reviewed the clinical characteristics of different BA subtypes and revealed the molecular mechanisms of their developmental contributors. We aimed to highlight the differences among these various subtypes of BA which ultimately contribute to the development of a specific management protocol for each subtype.

The Liver Biopsy in Neonatal Cholestasis: Just a Cherry on Top?

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Congenital anomalies of the gastrointestinal tract: the liver, extrahepatic biliary tree and pancreas

Congenital anomalies of the liver, biliary tree and pancreas are rare birth defects, some of which are characterized by a marked variation in geographical incidence. Morphogenesis of the hepatobiliary and pancreatic structures initiates from two tubular endodermal evaginations of the most distal portion of the foregut. The pancreas develops from a larger dorsal and a smaller ventral outpouching; emergence of the two buds will eventually lead to the fusion of the duct system. A small part of the remaining ventral diverticulum divides into a "pars cystica" and "pars hepatica", giving rise to the cystic duct and gallbladder and the liver lobes, respectively. Disruption or malfunctioning of the complex mechanisms leading to the development of liver, gallbladder, biliary tree and pancreas can result in numerous, albeit fortunately relatively rare, congenital anomalies in these organs. The type and severity of anomalies often depend on the exact moment in which disruption or alteration of the embryological mechanisms takes place. Many theories have been brought forward to explain their embryological basis; however, no agreement has yet been reached for most of them. While in some cases pathological evaluation might be more centered on macroscopic evaluation, in other instances small biopsies will be the keystone to understanding organ function and treatment results in the context of congenital anomalies. Thus, knowledge of the existence and histopathological characteristics of some of the more common conditions is mandatory for every pathologist working in the field of gastrointestinal pathology.

Critical diagnoses in paediatric gastrointestinal diseases

Gastrointestinal biopsies represent an increasing proportion of the paediatric pathologist's workload, an increase fundamentally due to an expansion of the understanding of the basic clinical, molecular, genetic, and histopathological features of paediatric gastrointestinal disorders. The histological interpretation of endoscopically retrieved gastrointestinal biopsies in children requires a unique set of diagnostic expertise and detailed knowledge of various gastrointestinal disorders that have a predilection for the paediatric population. This article's major role is to highlight the unique problems inherent to paediatric gastrointestinal disorders that require immediate communication with the paediatric surgeon or the gastroenterologist. For this, we tried to cover the most important diseases that a paediatric pathologist might encounter in daily practice. Some of these diseases are relatively rare, such as microvillous inclusion disease and tufting enteropathy, but some are more common such as eosinophilic disorders and inflammatory bowel disease. Awareness of the histopathological features of these diseases, particularly those that are relatively uncommon, is crucial to spare the patient a lengthy and costly evaluation. We made a particular effort to abundantly reference this article should the reader wish to expand on the content of any section.

The utility of shear wave elastography and serum biomarkers for diagnosing biliary atresia and predicting clinical outcomes

To investigate the utility of liver stiffness measurement by shear wave elastography (SWE) and several commonly used biomarkers in differentiating biliary atresia (BA) from other causes of cholestasis (non-BA) patients within 45 days and in predicting the postoperative prognosis. A consecutive series of medical records of patients presenting with cholestasis within 45 days in our institution between February 2016 and December 2020 was collected. The BA diagnosis was confirmed by intraoperative cholangiography (IOC). Other causes of cholestasis were confirmed by IOC, liver biopsy, genetic analysis, or recovery after conservative treatment. Preoperative and postoperative data were analyzed. A total of 156 patients were included, consisting of BA (n = 83) and non-BA (n = 73) cases. SWE and serum gamma-glutamyl transferase (GGT) showed better discriminative utility. The optimal cutoff values for SWE and GGT were > 7.10 kPa and > 195.4 U/L, with AUC of 0.82 (95% CI, 0.76-0.89; p < 0.0001) and 0.87 (95% CI, 0.82-0.93; p < 0.0001), respectively. Subgroup analysis showed the increased discriminative performance of SWE with age. Multivariable logistic regression analysis showed better diagnostic performance for SWE (adjusted OR, 35.03; 95% CI, 7.12-172.50) and GGT (adjusted OR, 24.70; 95% CI, 6.55-93.18) after adjusting for other confounders. The 30-day postoperative to preoperative serum direct bilirubin (DB) level, DB (post-30:pre), of > 0.3 showed the best predictive value for the need of liver transplantation, with HR of 6.15 (95% CI 1.95-19.38, P = 0.042).Conclusion: Serum GGT level and liver stiffness measurement by SWE showed the best discriminative utility. The diagnostic performance of SWE increased with age. A DB (post-30:pre) value > 0.3 was associated with the need for liver transplantation in later life. What is Known: • Liver stiffness measurement by shear wave elastography (SWE) could help discriminate biliary atresia (BA) from other causes of cholestasis, with sensitivity of 70-90%. • The postoperative total bilirubin less than 2 mg/dL within the first 3 months was a predictor of transplant-free survival. What is New: • The diagnostic performance of liver stiffness measurement by SWE increased with age. • The 30-day postoperative direct bilirubin (DB) level to preoperative DB level, DB (post-30:pre), is a predictor for short-term clinical outcomes.

Diagnostic approach to neonatal and infantile cholestasis: A position paper by the SIGENP liver disease working group

Neonatal and infantile cholestasis (NIC) can represent the onset of a surgically correctable disease and of a genetic or metabolic disorder worthy of medical treatment. Timely recognition of NIC and identification of the underlying etiology are paramount to improve outcomes. Upon invitation by the Italian National Institute of Health (ISS), an expert working grouped was formed to formulate evidence-based positions on current knowledge about the diagnosis of NIC. A systematic literature search was conducted to collect evidence about epidemiology, etiology, clinical aspects and accuracy of available diagnostic tests in NIC. Evidence was scored using the GRADE system. All recommendations were approved by a panel of experts upon agreement of at least 75% of the members. The final document was approved by all the panel components. This position document summarizes the collected statements and defines the best-evidence diagnostic approach to cholestasis in the first year of life.

Neonatal Cholestasis: Updates on Diagnostics, Therapeutics, and Prevention

Cholestatic jaundice is a common presenting feature of hepatobiliary and/or metabolic dysfunction in the newborn and young infant. Timely detection of cholestasis, followed by rapid step-wise evaluation to determine the etiology, is crucial to identify those causes that are amenable to medical or surgical intervention and to optimize outcomes for all infants. In the past 2 decades, genetic etiologies have been elucidated for many cholestatic diseases, and next-generation sequencing, whole-exome sequencing, and whole-genome sequencing now allow for relatively rapid and cost-effective diagnosis of conditions not previously identifiable via standard blood tests and/or liver biopsy. Advances have also been made in our understanding of risk factors for parenteral nutrition-associated cholestasis/liver disease. New lipid emulsion formulations, coupled with preventive measures to decrease central line-associated bloodstream infections, have resulted in lower rates of cholestasis and liver disease in infants and children receiving long-term parental nutrition. Unfortunately, little progress has been made in determining the exact cause of biliary atresia. The median age at the time of the hepatoportoenterostomy procedure is still greater than 60 days; consequently, biliary atresia remains the primary indication for pediatric liver transplantation. Several emerging therapies may reduce the bile acid load to the liver and improve outcomes in some neonatal cholestatic disorders. The goal of this article is to review the etiologies, diagnostic algorithms, and current and future management strategies for infants with cholestasis.

Adequacy criteria of Tru-cut needle liver biopsy in neonatal cholestasis

INTRODUCTION AND OBJECTIVES

Assessment of liver biopsy sample adequacy criteria is essential to avoid sampling errors in patients with diffuse liver pathology. Many studies have evaluated these criteria in adults; however, no previous studies have been performed on neonatal liver disorders. We aimed to assess the adequacy criteria of Tru-cut needle liver biopsy samples in infants with neonatal cholestasis (NC).

METHODS

In a retrospective analysis of infants who underwent liver biopsy for NC within a one-year duration, 58 specimens were recruited. The core lengths after fixation were measured. All samples were acquired with a 16-gauge (G) Tru-cut needle. Serial shortening of these samples was performed to define the smallest core length that gives representative parenchyma that could determine the activity grade and fibrosis stage reported by larger cores.

RESULTS

It was found that a 4-mm core length with a complete portal tract (CPT) number of 8±3 could adequately assess the NC activity grade. In addition, a 6-mm core length with a CPT number of 11±3 could adequately estimate NC fibrosis stage.

CONCLUSIONS

The adequacy criteria of liver tissue samples for the accurate assessment of NC are different from those defined for adult diffuse liver pathology. At least a 4-mm core length with a CPT number of 8±3 and a 6-mm core length with a CPT number of 11±3 acquired by a 16-G Tru-cut needle should be used to assess NC activity grade and fibrosis stage, respectively.

Temporal histopathological changes in biliary atresia: A perspective for rapid fibrosis progression

INTRODUCTION AND OBJECTIVES

Biliary atresia (BA) is characterized by rapid progression of fibrosis with no definite causes. Histopathological findings have been extensively described, but very few studies have assessed temporal changes in BA. Understanding these short-term changes and their relationship with fibrosis progression could have an impact on ameliorating rapid fibrogenesis. We aimed to study the relationship between temporal histopathological changes and fibrosis progression in BA within a short time interval.

PATIENTS AND METHODS

Forty-nine infants with BA who underwent Kasai portoenterostomy, a diagnostic liver biopsy, and an intraoperative liver biopsy were recruited. Histopathological characteristics of the two biopsies were examined. Temporal histopathological changes were assessed by comparing the two types of biopsies. Correlation of temporal changes in fibrosis with age, interval between biopsies, laboratory profiles, and temporal histopathological changes were studied.

RESULTS

In the univariate analysis, bile ductular proliferation (BDP), portal infiltrate, giant cells, hepatocellular swelling, and fibrosis showed significant temporal changes within a short interval (5-31 days). BDP and fibrosis showed the most frequent increase in their grades (32/49 and 31/49 cases, respectively). In the multivariate analysis, BDP was the only independent pathological feature showing a significant temporal increase (p = 0.021, 95% confidence interval: 1.249-16.017). Fibrosis progression was correlated with temporal changes in BDP (r = 0.456, p = 0.001), but not with age (p = 0.283) or the interval between the biopsies (p = 0.309).

CONCLUSIONS

Fibrosis in BA progresses rapidly and is significantly correlated with BDP. Assessment of targeting BDP as an adjuvant medical therapy is recommended.

Practical approach for the diagnosis of biliary atresia on imaging, part 2: magnetic resonance cholecystopancreatography, hepatobiliary scintigraphy, percutaneous cholecysto-cholangiography, endoscopic retrograde cholangiopancreatography, percutaneous liver biopsy, risk scores and decisional flowchart

We aim to present a practical approach to imaging in suspected biliary atresia, an inflammatory cholangiopathy of infancy resulting in progressive fibrosis and obliteration of extrahepatic and intrahepatic bile ducts. Left untreated or with failure of the Kasai procedure, biliary atresia progresses to biliary cirrhosis, end-stage liver failure and death within the first years of life. Differentiating biliary atresia from other nonsurgical causes of neonatal cholestasis is difficult as there is no single method for diagnosing biliary atresia and clinical, laboratory and imaging features of this disease overlap with those of other causes of neonatal cholestasis. In this second part, we discuss the roles of magnetic resonance (MR) cholecystopancreatography, hepatobiliary scintigraphy, percutaneous biopsy and percutaneous cholecysto-cholangiography. Among imaging techniques, ultrasound (US) signs have a high specificity, although a normal US examination does not rule out biliary atresia. Other imaging techniques with direct opacification of the biliary tree combined with percutaneous liver biopsy have roles in equivocal cases. MR cholecystopancreatography and hepatobiliary scintigraphy are not useful for the diagnosis of biliary atresia. We propose a decisional flowchart for biliary atresia diagnosis based on US signs, including elastography, percutaneous cholecysto-cholangiography or endoscopic retrograde cholangiopancreatography and liver biopsy.

SOX9 in biliary atresia: New insight for fibrosis progression

BACKGROUND

Liver fibrosis is a hallmark determinant of morbidity in biliary atresia (BA) even in successfully operated cases. Responsible factors for this rapid progression of fibrosis are not completely defined. Aberrant expression of the transcription factor SOX9 and hepatic progenitor cells (HPCs) proliferation have roles in fibrogenesis in cholestatic disorders. However, they were not investigated sufficiently in BA. We aimed to delineate the relation of SOX9 and HPCs to fibrosis and its progression in BA.

METHODS

Forty-eight patients with BA who underwent an initial diagnostic liver biopsy (LB) and consequent intraoperative LB were recruited and compared to 28 cases with non-BA cholestasis that had an LB in their diagnostic workup. Liver fibrosis, tissue SOX9 and HPC expressions were studied in both BA and non-BA-cholestasis cases. Liver fibrosis, SOX9, and HPCs' dynamic changes in BA cases were assessed. Relation of fibrosis and its progression to SOX9 and HPCs in BA was assessed.

RESULTS

SOX9 and HPCs in ductular reaction (DR) form were expressed in 100% of BA and their grades increased significantly in the second biopsy. The rapidly progressive fibrosis in BA, represented by fibrosis grade of the intraoperative LB, correlated significantly to SOX9-DR and HPC-DR at the diagnostic (r = 0.420, P = 0.003 and r = 0.405, P = 0.004, respectively) and the intraoperative (r = 0.460, P = 0.001 and r = 0.467, P = 0.001, respectively) biopsy. On the other hand, fibrosis, SOX9-DR, and HPC-DR were significantly lower in non-BA cases at a comparable age (P < 0.001, P = 0.006, and P = 0.014, respectively).

CONCLUSIONS

Fibrosis in BA is rapidly progressive within a short time and is significantly correlated to SOX9 and HPCs. Assessment of targeting SOX9 and HPCs on fibrosis progression is warranted.

Operational Definitions for Chronic Liver Disease Manifestations and Recurring Clinical Events in Biliary Atresia

BACKGROUND

The disease course of biliary atresia (BA) may be complicated by development of chronic liver disease (CLD) manifestations (eg, ascites) and recurring clinical events (eg, cholangitis). Most pediatric CLD-manifestations/events lack standardized operational definitions, leading to inconsistent identification in clinical research. This study aimed to develop operational research definitions of CLD-manifestations/events in BA for application in retrospective analysis.

METHODS

Operational definitions of CLD-manifestations/events were developed by literature review and revised by a panel of experienced pediatric hepatologists. Definitions were applied to a single-center review of infants with BA post-Kasai. Manifestations/events were captured until last clinical visit with native liver (SNL), liver transplantation (LT), or death. Native liver survival and event-free survival were estimated by Kaplan-Meier method. Cluster analysis was performed to identify similar patterns of manifestation/event development.

RESULTS

Of 65 infants with BA post-Kasai (2006-18; median Kasai 56.8 days; 65% girls), 29 underwent LT (median 12.9 months) and 4 died without LT (median 6.9 months). Seventy-six percent of CLD-manifestations/events presented within the first year. Presence of definite clinically evident portal hypertension, thrombocytopenia, and dCE ascites were associated with poor transplant-free survival (P < 0.01). Similar pattern developments of CLD-manifestations/events identified 3 outcome groups: poor outcomes (87.8% LT/death), SNL with manifestations/events, and SNL with few/no events.

CONCLUSIONS

Operational definitions can provide a timely description of the disease course progression in infants with BA. Research definitions may provide better consistency in future pediatric CLD studies. Furthermore, definitions may serve as endpoints in therapeutic trials or used as variables for disease pattern identification in potential multicenter studies.

Rodent models of cholestatic liver disease: A practical guide for translational research

Cholestatic liver disease denotes any situation associated with impaired bile flow concomitant with a noxious bile acid accumulation in the liver and/or systemic circulation. Cholestatic liver disease can be subdivided into different types according to its clinical phenotype, such as biliary atresia, drug-induced cholestasis, gallstone liver disease, intrahepatic cholestasis of pregnancy, primary biliary cholangitis and primary sclerosing cholangitis. Considerable effort has been devoted to elucidating underlying mechanisms of cholestatic liver injuries and explore novel therapeutic and diagnostic strategies using animal models. Animal models employed according to their appropriate applicability domain herein play a crucial role. This review provides an overview of currently available in vivo animal models, fit-for-purpose in modelling different types of cholestatic liver diseases. Moreover, a practical guide and workflow is provided which can be used for translational research purposes, including all advantages and disadvantages of currently available in vivo animal models.

Role of percutaneous liver biopsy in infantile cholestasis: cohort from Arabs

Background

Investigators from different parts of the world are calling for a re-evaluation of the role of liver biopsy (LB) in the evaluation of infantile cholestasis (IC), especially in the light of emerging non-invasive diagnostic technologies. Therefore, this retrospective single-center study was conducted to determine the impact of LB on the diagnosis and management of IC in a cohort from Arabs.

Methods

From 2007 until 2019, 533 cases of IC were referred for evaluation. All infants who underwent LB were included in the study. We categorized the yield of LB into: (1) defined specific diagnosis; (2) excluded an important diagnosis. A single pathologist reviewed and made the histology report.

Results

122 LB specimens met the inclusion criteria. The main indication for LB was a high suspicion of biliary atresia (BA) [high gamma-glutamyl transferase (GGT) cholestasis and pale stool] in 46 cases (37.8%). Liver biopsy had sensitivity of 86.4%, specificity (66.7%), PPV (70.4%), NPV (84.2%) in diagnosing BA. LB had a direct impact on clinical management in 52 cases (42.6%): (1) The true diagnosis was suggested by LB in 36 cases; (2) LB excluded BA and avoided intraoperative cholangiogram in 16 cases with high suspicion of BA. Among the 76 cases with low suspicion of BA, LB suggested the true diagnosis or helped to initiate specific management in 8 cases only (10.5%). In contrast, molecular testing confirmed the diagnosis in 48 (63%).

Conclusion

LB continues to be an important tool in the workup of cases with a high suspicion of BA. The low yield of LB in cases with low suspicion of BA calls for a re-evaluation of its role in these cases in whom early incorporation of cholestasis sequencing gene  panels can have a better diagnostic yield.

Differentiating Biliary Atresia From Idiopathic Neonatal Hepatitis: A Novel Keratin 7 Based Mathematical Approach on Liver Biopsies

BACKGROUND AND AIMS

Differentiating biliary atresia (BA) from idiopathic neonatal hepatitis (INH) is vital in routine pediatric practice. However, on liver biopsy, few cases offer a diagnostic challenge to discriminate these entities with certainty. Bile ductular reaction (DR), intermediate hepatobiliary cells (IHBC) and extra-portal ductules (EPD) indicate progenitor cell activation, as a response to various hepatic insults. The present study aims to quantify DR, IHBC and EPD by Keratin 7 (CK7) immunohistochemistry (IHC) in BA and INH and to devise a mathematical approach to better differentiate the two, especially in histologically equivocal cases.

METHODS

A total of 98 cases were categorized on biopsy as BA, INH or equivocal histology, favoring BA or INH. CK7 DR mean, IHBC mean and EPD mean values were compared between BA and INH. A formula was derived to help distinguish these two entities, the cut-off value, sensitivity and specificity of which were determined by receiver operating characteristic (ROC) curve. This formula was applied and validated on histologically equivocal cases.

RESULTS

Univariate logistic regression revealed significant difference between BA and INH with respect to CK7 DR and CK7 EPD mean (p < 0.001 in both); however, CK7 IHBC mean was not significant (p = 0.08). On multivariate logistic regression, only CK7 DR had significant impact on diagnosis (p < 0.001). A formula: (CK7 DR)² + (CK7 EPD)/(CK7 IHBC) was derived to help distinguish BA from INH. Cut off value of 10.5 and above, determined by ROC curve, favored a diagnosis of BA (sensitivity= 93.4%, specificity= 94.6%). Histologically equivocal and discrepant cases could be correctly categorized using this formula.

CONCLUSIONS

Formula using CK7 IHC parameters may aid pathologists better distinguish BA from INH, especially in histologically equivocal cases.

Practical approach to imaging diagnosis of biliary atresia, Part 1: prenatal ultrasound and magnetic resonance imaging, and postnatal ultrasound

We present a practical approach to imaging in suspected biliary atresia, an inflammatory cholangiopathy of infancy resulting in progressive fibrosis and obliteration of extrahepatic and intrahepatic bile ducts. Left untreated or with failure of the Kasai procedure, biliary atresia progresses towards biliary cirrhosis, end-stage liver failure and death by age 3. Differentiation of biliary atresia from other nonsurgical causes of neonatal cholestasis is challenging because there is no single method for diagnosing biliary atresia, and clinical, laboratory and imaging features of this disease overlap with those of other causes of neonatal cholestasis. Concerning imaging, our systematic literature review shows that ultrasonography is the main tool for pre- and neonatal diagnosis. Key prenatal features, when present, are non-visualisation of the gallbladder, cyst in the liver hilum, heterotaxy syndrome and irregular gallbladder walls. Postnatal imaging features have a very high specificity when present, but a variable sensitivity. Triangular cord sign and abnormal gallbladder have the highest sensitivity and specificity. The presence of macro- or microcyst or polysplenia syndrome is highly specific but less sensitive. The diameter of the hepatic artery and hepatic subcapsular flow are less reliable. When present in the context of acholic stools, dilated intrahepatic bile ducts rule out biliary atresia. Importantly, a normal US exam does not rule out biliary atresia. Signs of chronic hepatopathy and portal hypertension (portosystemic derivations such as patent ductus venosus, recanalised umbilical vein, splenomegaly and ascites) should be actively identified for - but are not specific for - biliary atresia.

Approaches to Research Determination of Late Acute Cellular Rejection in Pediatric Liver Transplant Recipients

A central pathology or site reading of biopsy slides is used in liver transplant clinical trials to determine rejection. We evaluated interrater reliability of readings of "rejection or not" using digitized slides from the Medication Adherence in Children who had a Liver Transplant (MALT) study. Four masked experienced pathologists read the digitized slides and then reread them after a study-specific histologic endpoint development program. Agreement was expressed throughout as a Kappa or Fleiss Kappa statistic (ҡ). A ҡ > 0.6 was predefined as desirable. Readings were correlated with immunosuppressant adherence (the Medication Level Variability Index, [MLVI]), and maximal liver enzyme levels during the study period. Interrater agreement between site and central review in MALT, and between 4 pathologists later on, was low (ҡ = 0.44, Fleiss ҡ = 0.41, respectively). Following the endpoint development program, agreement improved and became acceptable (ҡ = 0.71). The final reading was better-aligned with maximal gamma-glutamyl transferase levels and MLVI as compared with the original central reading. We found substantial disagreement between experienced pathologists reading the same slides. A unique study-specific procedure improved interrater reliability to the point it was acceptable. Such a procedure may be indicated to increase reliability of histopathologic determinations in future research, and perhaps also clinically.

Recent developments in diagnostics and treatment of neonatal cholestasis

Neonatal cholestasis is characterized by conjugated hyperbilirubinemia in the newborn and young infant and is a sign common to over 100 hepatobiliary and/or metabolic disorders. A timely evaluation for its etiology is critical in order to quickly identify treatable causes such as biliary atresia, many of which benefit from early therapy. An expanding group of molecularly defined disorders involving bile formation, canalicular transporters, tight junction proteins and inborn errors of metabolism are being continuously discovered because of advances in genetic testing and bioinformatics. The advent of next generation sequencing has transformed our ability to test for multiple genes and whole exome or whole genome sequencing within days to weeks, enabling rapid and affordable molecular diagnosis for disorders that cannot be directly diagnosed from standard blood tests or liver biopsy. Thus, our diagnostic algorithms for neonatal cholestasis are undergoing transformation, moving genetic sequencing to earlier in the evaluation pathway once biliary atresia, "red flag" disorders and treatable disorders are excluded. Current therapies focus on promoting bile flow, reducing pruritus, ensuring optimal nutrition, and monitoring for complications, without addressing the underlying cause of cholestasis in most instances. Our improved understanding of bile formation and the enterohepatic circulation of bile acids has led to emerging therapies for cholestasis which require appropriate pediatric clinical trials. Despite these advances, the cause and optimal therapy for biliary atresia remain elusive. The goals of this review are to outline the etiologies, diagnostic pathways and current and emerging management strategies for neonatal cholestasis.

The evolution of early liver biopsy findings in babies with jaundice may delay the diagnosis and treatment of biliary atresia

BACKGROUND

The early diagnosis of biliary atresia (BA) is associated with a better outcome after portoenterostomy. However, very early liver biopsy findings may appear atypical for BA and delay diagnosis. Repeat biopsy histology may change rapidly to show more typical features.

METHODS

Between 1997 and 2018, 6 babies with jaundice had more than one biopsy to establish diagnosis. Clinical and histologic data were collected. chi-Square was used for analysis (p < 0.05 significant).

RESULTS

Five patients had two biopsies, and one had three. Median age at first, second, and third biopsy was 40 (13-57), 68.5 (35-78), and 133 days, respectively. Biopsy readings showed no portal edema initially (0/6), but in all 6 on repeat biopsy (p = 0.001). Bile duct proliferation was seen in 6/6 final biopsies, but in only 1/6 initially (p = 0.003). All patients underwent a portoenterostomy (median age 75 days (43-113)). Median delay between initial biopsy and Kasai was 29 days (14-67). Transplant free survival (n = 5 patients) ranged from 184 to 716 days (median 309 days). One patient died before being transplanted.

CONCLUSION

Early biopsies may not display characteristic findings of BA, but these can appear quickly on subsequent evaluation. The interval needed to repeat a biopsy may have an adverse effect on bile drainage.

LEVEL OF EVIDENCE

IV.

Reduced Immunohistochemical Expression of Hnf1β and FoxA2 in Liver Tissue Can Discriminate Between Biliary Atresia and Other Causes of Neonatal Cholestasis

Biliary atresia (BA) is a necroinflammatory occlusive cholangiopathy that affects infants. Genetic and environmental factors has been proposed for its occurrence. The objectives of this study was to investigate the protein expression of 2 important genes regulating ductal plate remodeling, hepatocyte nuclear factor 1-beta (Hnf1β) and the fork head box protein A2 (FoxA2) in liver tissue from patients with BA and to compare their expression with other causes of neonatal cholestasis (NC). This retrospective study included 60 pediatric patients, 30 with BA and 30 with NC. Immunohistochemistry of Hnf1β and FoxA2 was performed on liver tissues from studied patients as well as 20 healthy subjects. Statistical analysis between immunohistochemistry results and other parameters was performed. Liver tissue from patients with BA revealed reduced Hnf1β and FoxA2 immunoexpression. A strong significant statistical difference between BA and NC group (P<0.0001) with regard to Hnf1β and FoxA2 immunoexpression was evident. Moreover, Hnf1β was significantly correlated with FoxA2 immunoexpression, stage of fibrosis, bile ductular proliferation, and bile plugs in bile ductules. Hnf1β immunoreaction in BA cases showed 76.7% sensitivity, 90% specificity, 88.5% positive predictive value, 79.4% negative predictive value, and 83.4% accuracy. FoxA2 expression in BA cases revealed 70.0% sensitivity, 80.0% specificity, 77.8% positive predictive value, 72.7% negative predictive value, 75.0% accuracy. Hnf1β and FoxA2 immunoexpression could differentiate between BA from other cause of NC.

Histopathological expression of Yes-associated protein in neonatal cholestasis

BACKGROUND

Biliary atresia (BA) is a common cause of persistent neonatal cholestasis and liver transplantation in the pediatric population. Yes-associated protein (YAP) has also been shown to be necessary for development of bile ducts and adaptive responses within the gastrointestinal tract. We aimed to evaluate the YAP expression in liver tissues of infants with neonatal cholestasis as well as its diagnostic potential in the differential diagnosis of BA.

PATIENTS AND METHODS

This prospective study included 100 infants with neonatal cholestasis. After full history taking, thorough clinical examination, routine investigations, and histopathological assessment, the patients were allocated as BA and non-BA; fifty patients in each group. Ten liver biopsies from 10 donors of liver transplant recipients served as controls. Diagnosis of BA was confirmed by operative cholangiography. Hepatic expression of YAP was assessed by immunohistochemical staining.

RESULTS

Presence of clay stool, elevated GGT and absence of gall bladder contractility were the main preliminary signs alarming for the possibility of BA. Bile ductular and interlobular biliary epithelium and hepatic lobule expression of YAP in patients with BA was significantly higher than that in Non-BA group (P<0.05). There was no or weak positive YAP expression in normal liver of transplant donors. Positive YAP immunohistochemical had a sensitivity of 80% and a specificity of 94% with accuracy 87% in discrimination between BA and non-BA group (P-value<0.0001).

CONCLUSION

Hepatic expression of YAP was significantly higher in BA than in non-BA group and could discriminate BA from other causes of cholestasis.

Biliary atresia: pathology, etiology and pathogenesis

Biliary atresia is a progressive fibrosing obstructive cholangiopathy of the intrahepatic and extrahepatic biliary system, resulting in obstruction of bile flow and neonatal jaundice. Histopathological findings in liver biopsies include the expansion of the portal tracts, with edematous fibroplasia and bile ductular proliferation, with bile plugs in duct lumen. Lobular morphological features may include variable multinucleate giant cells, bilirubinostasis and hemopoiesis. The etiopathogenesis of biliary atresia is multifactorial and multiple pathomechanisms have been proposed. Experimental and clinical studies have suggested that viral infection initiates biliary epithelium destruction and release of antigens that trigger a Th1 immune response, which leads to further injury of the bile duct, resulting in inflammation and obstructive scarring of the biliary tree. It has also been postulated that biliary atresia is caused by a defect in the normal remodelling process. Genetic predisposition has also been proposed as a factor for the development of biliary atresia.

Three-color risk stratification for improving the diagnostic accuracy for biliary atresia

OBJECTIVES

It is challenging to early differentiate biliary atresia from other causes of cholestasis. We aimed to develop an algorithm with risk stratification to distinguish biliary atresia from infantile cholestasis.

METHODS

In this study, we enrolled infants with cholestasis into 2 subgroups from January 2010 to April 2019. A prospective cohort (subgroup 2) of 187 patients (107 with biliary atresia and 80 without biliary atresia) underwent acoustic radiation force impulse elastography. Stepwise regression was used to identify significant predictors of biliary atresia. A sequential algorithm with risk stratification was constructed.

RESULTS

Among 187 patients, shear wave speed > 1.35 m/s and presence of the triangular cord sign were considered high risk for biliary atresia (red), in which 73 of 78 patients (accuracy of 93.6%) with biliary atresia were identified. Afterwards, γ-GT, abnormal gallbladder, and clay stool were introduced into the algorithm and 55 intermediate-risk infants were identified (yellow) with a diagnostic accuracy of 60% for biliary atresia. Of the remaining 54 infants who were classified as low-risk patients (green), the accuracy for excluding biliary atresia was 98.1%. By applying a three-color risk stratification tool, 70.6% patients were identified as either high risk or low risk for biliary atresia (area under the curve, 0.983; sensitivity, 98.7%; specificity, 91.4%). We also estimated the risk of biliary atresia in different color groups, which was 94.7% (95%CI, 94.3-95.5%) in the red group and 7.2% (95%CI, 6.6-8.3%) in the green group.

CONCLUSIONS

Our simple noninvasive approach was able to identify biliary atresia with high accuracy.

KEY POINTS

• Five predictors, namely shear wave speed, triangle cord sign, γ-glutamyl transferase, abnormal gallbladder, and clay stool, were selected to identify biliary atresia in cholestasis. • Shear wave speed > 1.35 m/s and presence of the triangle cord sign were considered high-risk patients with a diagnostic accuracy of 93.6% for biliary atresia. • Risk for biliary atresia was high (red), intermediate (yellow), or low (green). In the red and green group, we achieved an extremely high diagnostic performance (area under the curve, 0.983; sensitivity, 98.7%; specificity, 91.4%).

YAP Activation and Implications in Patients and a Mouse Model of Biliary Atresia

Background and Aim: Biliary atresia (BA), an inflammatory destruction of the bile ducts, leads to liver fibrosis in infants and accounts for half of cases undergoing pediatric liver transplantation. Yes-associated protein (YAP), an effector of the Hippo signaling pathway, is critical in maintaining identities of bile ductal cells. Here, we evaluated the expression of YAP and YAP target genes in BA livers and a rhesus rotavirus (RRV)-induced BA mice model. Methods: Liver specimens collected from 200 BA patients were compared with those of 30 non-BA patients. Model mice liver tissues were also collected. The expression of YAP and YAP target genes were measured by transfection, RNA-seq, immunohistochemistry, immunoblot, and quantitative PCR. Masson's trichrome staining and the Biliary Atresia Research Consortium (BARC) system were utilized to score liver fibrosis status. Results: The expression of YAP is elevated and positively correlated with fibrosis in BA livers. Moreover, ANKRD1, which is identified as the target gene of YAP, is also highly expressed in BA livers. Consistent with clinical data, YAP and ANKRD1 are significantly upregulated in RRV-induced BA mouse model. Conclusions: YAP expression is closely correlated with the bile duct hyperplasia and liver fibrosis, and may serve as an indicator for liver fibrosis and BA progression. This study indicates an involvement of the Hippo signaling pathway in the development of BA, and the YAP induced ANKRD1 expression may also be related to bile duct hyperplasia in BA. This provides a new direction for more in-depth exploration of the etiology and pathogenesis of biliary atresia.

Needle liver biopsy has potential for delaying Kasai portoenterostomy and Is obsolete for diagnosing biliary atresia in the laparoscopic era

AIM

Early diagnosis is essential for the successful management of biliary atresia (BA). We assessed the efficacy of our diagnostic strategies for BA in the laparoscopic era.

METHODS

A retrospective review of the medical records of 132 infants presenting with suspected BA between 1998 and 2018 was performed to assess the efficacy of "basic" tests (blood biochemistry, abdominal ultrasound, and Tc-99m N-pyrydoxyl-5-methyltriptophane liver scintigraphy) and the value of laparoscopic assessment of the porta hepatis and/or cholangiography for choosing between Kasai portoenterostomy (PE) or cholangiodrainage (CD) for treatment.

RESULTS

BA was excluded on "basic" tests in 7 cases: 109/125 had BA diagnosed laparoscopically and proceeded immediately to PE. Nonatrophic gallbladder cases (n = 10) had CD and other morbidity diagnosed on liver biopsy (Bx; n = 6). Sensitivity, specificity, and accuracy of diagnosis using "basic" tests were 100%, 30.4%, and 87.9%, respectively. Accuracy of laparoscopy without Bx was 100%, allowing immediate progression to PE without waiting for Bx results or trauma from Bx to heal. "Basic" tests and laparoscopy can be completed within one week.

CONCLUSIONS

A combination of "basic" tests and laparoscopy can diagnose BA promptly and accurately without Bx. Bx is essentially unnecessary for diagnosing BA if laparoscopy is performed.

TYPE OF STUDY

Study of diagnostic test.

LEVEL OF EVIDENCE

Level III.

Neonatal cholestasis: recent insights

Background

Neonatal physiological jaundice is a common benign condition that rarely extends behind the second week of life; however, it may interfere with the diagnosis of a pathological condition termed neonatal cholestasis (NC). The latter is a critical, uncommon problem characterized by conjugated hyperbilirubinaemia. This review aims to highlight the differences between physiological and pathological jaundice, identify different causes of NC, and provide a recent approach to diagnosis and management of this serious condition.

Main text

NC affects 1/2500 live births, resulting in life-threatening complications due to associated hepatobiliary or metabolic abnormalities. NC is rarely benign and indicates the presence of severe underlying disease. If jaundice extends more than 14 days in full-term infants or 21 days in preterm infants, the serum bilirubin level fractionated into conjugated (direct) and unconjugated (indirect) bilirubin should be measured. A stepwise diagnostic approach starts with obtaining a complete history, and a physical examination which are valuable for the rapid diagnosis of the underlying disease. The most frequently diagnosed causes of NC are biliary atresia (BA) and idiopathic neonatal hepatitis (INH). The early diagnosis of NC ensures more accurate management and better prognosis. Despite the unavailability of any specific treatments for some causes of NC, the patient can benefit from nutritional management and early medical intervention. Future research should attempt to shed light on methods of screening for NC, especially for causes that can be effectively treated either through proper nutritional support, appropriate chemotherapeutic management, or timely surgical intervention.

Conclusion

Further attention should be paid for diagnosis and treatment of NC as it may be misdiagnosed as physiological jaundice; this may delay the proper management of the underlying diseases and aggravates its complications.

Biliary Atresia as a Disease Starting In Utero: Implications for Treatment, Diagnosis, and Pathogenesis

Biliary atresia (BA) is the most common reason for pediatric liver transplant. BA's varied presentation, natural history, and treatment with the Kasai portoenterostomy have been well described; however, when BA starts relative to birth has not been clearly defined. In this review, we discuss laboratory, imaging, and clinical data which suggest that most if not all forms of BA may start before birth. This early onset has implications in terms of delivering treatments earlier and identifying possible factors underlying BA's etiology.

Preoperative alkaline phosphatase is a potential predictor of short-term outcome of surgery in infants with biliary atresia

Aim of the study

Biliary atresia (BA) is a fibro-inflammatory cholangiopathy of intra- and extrahepatic biliary radicles. The standard-of-care treatment is surgical restoration of bile flow by Kasai hepatoportoenterostomy (HPE). We aimed to identify the predictors of short-term outcome of the Kasai operation three months postoperatively.

Material and methods

This retrospective study included 107 infants diagnosed with BA by intraoperative cholangiography. All underwent a Kasai operation. The surgical outcome was classified after 3 months post-operatively as successful (bilirubin ≤ 2 mg/dl) or failed (bilirubin > 2 mg/dl). The two groups were compared according to basic clinical, ultrasonographic and histopathological characteristics.

Results

Of the studied patients 29 (27.1%) had a successful outcome while 78 (72.9%) had failed Kasai HPE. Of the preoperative characteristics, lower age and lower serum alkaline phosphatase (ALP) were significantly associated with successful surgical outcome (p = 0.009 and < 0.0001, respectively). In addition, surgical type of BA affected the short-term outcome (p = 0.017), while there was no statistically significant difference regarding the other studied parameters between groups. Age of 69.5 days or less was predictive of successful outcome with 74.4% specificity but with low sensitivity (58.6%), and ALP at a cutoff level of 532.5 U/l or less was predictive of successful outcome with 75.9% sensitivity and 74.4% specificity.

Conclusions

Younger age at the time of surgery and lower ALP are good predictors for the short-term outcome of Kasai HPE with better performance of ALP. This may help to anticipate those who can benefit from surgical correction and those who should be given high priority for transplant referral.

A practical approach to the pathology of neonatal cholestatic liver disease

Navigating the complexities of interpreting a liver biopsy performed on a neonate with conjugated/direct hyperbilirubinemia can be an arduous task given these biopsies are infrequently encountered. The list of entities is long and yet there are only a few histologic patterns of liver injury. The first step for the pathologist is to determine the histologic pattern, which will guide further inquiry into the useful clinical information to have while evaluating the biopsy. Ultimately, the goal is to identify those conditions that will benefit from early intervention. We begin with a review of biliary development to help understand what findings may be physiologic versus pathologic, particularly in premature infants. Then we review eight cases that cover the three most common histologic patterns of injury in patients with neonatal cholestasis: biliary obstructive, neonatal hepatitis, and paucity of intrahepatic bile ducts. The entities that serve as prototypes for these histologic patterns are covered, including biliary atresia, idiopathic neonatal hepatitis, and Alagille syndrome, along with rarer entities that have histologic overlap. The cases with accompanying tables and algorithms are intended to help place the histologic findings in the context of the overall clinical work-up, including genetic testing.