Native liver histology after successful portoenterostomy in biliary atresia

The clinical impact of macrophage polarity after Kasai portoenterostomy in biliary atresia

Introduction

Biliary atresia (BA) is a cholestatic hepatopathy caused by fibrosing destruction of intrahepatic and extrahepatic bile ducts, and its etiology has not been clearly revealed. In BA, liver fibrosis progression is often observed even after Kasai portoenterostomy (KPE), and more than half of cases require liver transplantation in their lifetime in Japan. Macrophages play an important role in liver fibrosis progression and are classically divided into proinflammatory (M1) and fibrotic macrophages (M2), whose phenotypic transformation is called "macrophage polarity." The polarity has been reported to reflect the tissue microenvironment. In this study, we examined the relationship between macrophage polarity and the post-KPE clinical course.

Materials and methods

Thirty BA patients who underwent KPE in our institution from 2000 to 2020 were recruited. Multiple immunostainings for CD68, CD163, CK19, and α-SMA were carried out on liver biopsy specimens obtained at KPE. ROC curves were calculated based on each clinical event, and the correlation with the clinical data was analyzed.

Results and discussion

The M2 ratio, defined as the proportion of M2 macrophages (CD163-positive cells), was correlated inversely with the occurrence of postoperative cholangitis (AUC: 0.7602). The patients were classified into M2 high (n = 19) and non-high (n = 11) groups based on an M2 ratio value obtained from the Youden index ( = 0.918). As a result, pathological evaluations (Metavir score, αSMA area fraction, and CK19 area fraction) were not significantly different between these groups. In mild liver fibrosis cases (Metavir score = 0-2), the M2 non-high group had a significantly lower native liver survival rate than the high group (p = 0.02). Moreover, 4 out of 8 cases in the M2 non-high group underwent early liver transplantation within 2 years after KPE.

Conclusions

Non-M2 macrophages, including M1 macrophages, may be correlated with postoperative cholangitis, and the M2 non-high group in mild liver fibrosis cases had a significantly lower native liver survival rate than the high group, requiring early liver transplantation in this study. Preventing advanced liver fibrosis is a key factor in improving native liver survival for BA patients, and liver macrophages may play important roles in liver homeostasis and the promotion of inflammation and fibrosis.

Deep learning quantification reveals a fundamental prognostic role for ductular reaction in biliary atresia

BACKGROUND

We aimed to quantify ductular reaction (DR) in biliary atresia using a neural network in relation to underlying pathophysiology and prognosis.

METHODS

Image-processing neural network model was applied to 259 cytokeratin-7-stained native liver biopsies of patients with biliary atresia and 43 controls. The model quantified total proportional DR (DR%) composed of portal biliary epithelium (BE%) and parenchymal intermediate hepatocytes (PIH%). The results were related to clinical data, Sirius Red-quantified liver fibrosis, serum biomarkers, and bile acids.

RESULTS

In total, 2 biliary atresia biopsies were obtained preoperatively, 116 at Kasai portoenterostomy (KPE) and 141 during post-KPE follow-up. DR% (8.3% vs. 5.9%, p=0.045) and PIH% (1.3% vs. 0.6%, p=0.004) were increased at KPE in patients remaining cholestatic postoperatively. After KPE, patients with subsequent liver transplantation or death showed an increase in DR% (7.9%-9.9%, p = 0.04) and PIH% (1.6%-2.4%, p = 0.009), whereas patients with native liver survival (NLS) showed decreasing BE% (5.5%-3.0%, p = 0.03) and persistently low PIH% (0.9% vs. 1.3%, p = 0.11). In Cox regression, high DR predicted inferior NLS both at KPE [DR% (HR = 1.05, p = 0.01), BE% (HR = 1.05, p = 0.03), and PIH% (HR = 1.13, p = 0.005)] and during follow-up [DR% (HR = 1.08, p<0.0001), BE% (HR = 1.58, p = 0.001), and PIH% (HR = 1.04, p = 0.008)]. DR% correlated with Sirius red-quantified liver fibrosis at KPE (R = 0.47, p<0.0001) and follow-up (R = 0.27, p = 0.004). A close association between DR% and serum bile acids was observed at follow-up (R = 0.61, p<0.001). Liver fibrosis was not prognostic for NLS at KPE (HR = 1.00, p = 0.96) or follow-up (HR = 1.01, p = 0.29).

CONCLUSIONS

DR predicted NLS in different disease stages before transplantation while associating with serum bile acids after KPE.

The AST-to-Platelet Ratio Index (APRi) at Kasai Portoenterostomy: Standing the Test of Time

AIMS

The outcomes following surgical treatment of infants with biliary atresia (BA) varies across the world with many possible confounding factors. APRi (AST-to-platelet ratio index) is a simple surrogate marker of liver fibrosis and we sought to determine its long-term relationship (if any) with outcome post-Kasai portoenterostomy (KPE).

METHODS

Prospectively acquired database (Jan 1998-Dec 2021). Clearance of jaundice was defined as achieving <20 umol/L post-KPE. Categorical and survival data were tested using Chi2 tests and a log rank test respectively. P ≤ 0.05 was regarded as significant. Data are quoted as median (interquartile range) unless otherwise stated.

RESULTS

There were 473 infants with a calculated APRi at time of KPE [0.70 (IQR 0.45-1.2)] and known outcomes. There was significant but moderate correlation with age at KPE (rS = 0.43; P < 0.0001). APRi was divided into quartiles (1st 0.11-0.44, n = 120; 2nd 0.45-0.69, n = 120; 3rd 0.70-1.18, n = 115 and 4th 1.2-15.1; n = 118). There was a clear distinction in APRi levels between CMV + ve BA and the other groups (Syndromic BA, Cystic BA, Isolated BA), with an overrepresentation of CMV IgM + ve BA in the higher APRi quartiles (Χ2 = 26.6; P = 0.0002). Clearance of jaundice showed a stepwise decrease across the quartiles (67%; 58%; 55%; 49%; overall Χ2 = 7.8, P = 0.049 and P = 0.005 for trend). Decreasing native liver survival also showed a significant trend (P = 0.01).

CONCLUSION

APRi appears to be of fundamental prognostic value in stratifying the BA population. In our series, CMV status was associated with higher APRi score and appears to be different. This simple variable offers an objective method of assessing the biological status of BA at presentation and variability between different series.

LEVEL OF EVIDENCE

II (prospective comparison).

Development of liver inflammatory injury in biliary atresia: from basic to clinical research

Biliary atresia (BA) is a severe cholangiopathy in infants. It is characterized by inflammatory fibro-obliteration of the intra- and extrahepatic bile ducts. Although the restoration of bile flow can be successful after Kasai operation, the rapid progression of liver fibrosis can continue, leading to cirrhosis. It is believed that the progression of liver fibrosis in BA is exacerbated by complicated mechanisms other than the consequence of bile duct obstruction. The fibrogenic cascade in BA liver can be divided into three stages, including liver inflammatory injury, myofibroblast activation, and fibrous scar formation. Recent studies have revealed that the activation of an immune response following bile duct injury plays an important role in promoting the inflammatory process, the releasing of inflammatory cytokines, and the development of fibrogenesis in BA liver. In this article, we summarized the evidence regarding liver inflammatory injury and the possible mechanisms that explain the rapid progression of liver fibrosis in BA.

Systematic review: The quality of life of patients with biliary atresia

BACKGROUND

The quality of life of patients with Biliary Atresia (BA) have not been systematically examined. The goal of this meta-analysis is to determine patients' postoperative health-related Quality of life (HrQoL) with native or transplanted livers.

METHODS

From 2000 to August 2021, a literature-based search for relevant cohorts was conducted using Pubmed/Medline, the Cochrane Library, and Embase. Original research on BA, Hepatoportoenterostomy (HPE), portoenterostomy, Kasai, Liver transplantation and HrQoL was included. Using RevMan, a forest plot analysis of HrQoL after surgical treatment after BA was calculated (version 5.4). Using MetaXL, a pooled prevalence for cholangitis, secondary liver transplantation, or related malformations was computed (version 5.3).

RESULTS

Nine studies compared individuals with BA to an age-matched healthy control group. 4/9 (n = 352) of these studies found poorer scores for BA patients, while 5/9 (n = 81) found equivalent health status. Factors associated with HrQoL: older age at the time of the survey was linked to greater HrQoL; whereas females, higher total bilirubin and the amount of immunosuppressive medicines were associated with lower HrQoL in BA patients.

CONCLUSION

The current study emphasises the critical need to improve the many parameters influencing HrQoL in BA patients, as well as the methods utilized to assess those factors. This includes immunosuppression, withdrawal from polydrug regimes and recognizing the differences in disease burden between males and females.

TYPE OF STUDY

Systematic review.

LEVEL OF EVIDENCE

Level III.

Metabolic regulation of cholestatic liver injury by D-2-hydroxyglutarate with the modulation of hepatic microenvironment and the mammalian target of rapamycin signaling

Biliary atresia (BA) is a cholestatic liver disease in neonates with devastating obstructive intrahepatic and extrahepatic biliary ducts. Owing to the lack of an early diagnostic marker and limited understanding of its pathogenesis, BA often leads to death within 2 years. Therefore, this study aimed to develop early diagnostic methods and investigate the underlying pathogenesis of liver injury in BA using metabolomics. Metabolomics and organoid combined energy metabolism analysis was used to obtain new insights into BA diagnosis and pathobiology using patient samples, mice liver organoids, and a zebrafish model. Metabolomics revealed that D-2-hydroxyglutarate (D-2-HG) levels were significantly elevated in the plasma and liver of patients with BA and closely correlated with liver injuries and impaired liver regeneration. D-2-HG suppressed the growth and expansion of liver organoids derived from the intrahepatic biliary ducts. The energy metabolism analysis demonstrated that D-2-HG inhibited mitochondrial respiration and ATP synthase; however, it increased aerobic glycolysis in organoids. In addition, D-2-HG exposure caused liver degeneration in zebrafish larvae. Mechanistically, D-2-HG inhibited the activation of protein kinase B and the mammalian target of rapamycin signaling. These findings reveal that D-2-HG may represent a novel noninvasive diagnostic biomarker and a potential therapeutic target for infants with BA.

[New advances in the diagnosis and treatment of biliary atresia]

The diagnosis of biliary atresia (BA) is mainly based on clinical manifestations, screening, and related biochemistry tests. In recent years, the development of blood biomarkers and the improvement in ultrasound examination have made it possible for BA to be diagnosed at a younger age. In particular, matrix metalloproteinase-7 shows high sensitivity and specificity and has a higher diagnostic efficiency than existing biochemical parameters, thereby holding a promise for clinical application. Sound touch elastography can increase the diagnostic efficiency for BA in terms of diagnosis and prognostic evaluation. Surgery is still the only method for the treatment of BA at present, with the preferred surgical treatment regimen of Kasai portoenterostomy combined with pharmacotherapies for alleviating infection and inflammation, and the patients who fail Kasai portoenterostomy or have liver dysfunction may require liver transplantation to save their lives. Therefore, the current research on BA should focus on the biomarkers for early diagnosis, specifically targeted drugs, and drugs for preventing progressive liver fibrosis. This article reviews the current diagnosis and treatment methods for BA and discusses the potential research directions.

Liver secretin receptor predicts portoenterostomy outcomes and liver injury in biliary atresia

Biliary atresia (BA) is a chronic neonatal cholangiopathy characterized by fibroinflammatory bile duct damage. Reliable biomarkers for predicting native liver survival (NLS) following portoenterostomy (PE) surgery are lacking. Herein we explore the utility of 22 preidentified profibrotic molecules closely connected to ductular reaction (DR) and prevailing after successful PE (SPE), in predicting PE outcomes and liver injury. We used qPCR and immunohistochemistry in a BA cohort including liver samples obtained at PE (n = 53) and during postoperative follow-up after SPE (n = 25). Of the 13 genes over-expressed in relation to cholestatic age-matched controls at PE, only secretin receptor (SCTR) expression predicted cumulative 5-year NLS and clearance of jaundice. Patients in the highest SCTR expression tertile showed 34-55% lower NLS than other groups at 1-5 years after PE (P = 0.006-0.04 for each year). SCTR expression was also significantly lower [42 (24-63) vs 75 (39-107) fold, P = 0.015] among those who normalized their serum bilirubin after PE. Liver SCTR expression localized in cholangiocytes and correlated positively with liver fibrosis, DR, and transcriptional markers of fibrosis (ACTA2) and cholangiocytes (KRT7, KRT19) both at PE and after SPE. SCTR is a promising prognostic marker for PE outcomes and associates with liver injury in BA.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02795-2.

Impact of the Kasai Procedure and the Length of Native Liver Survival Time on Outcomes of Liver Transplantation for Biliary Atresia

The aim is to explore the impact of the Kasai procedure (KP) and the length of native liver survival time (NLST) on outcomes of liver transplantation (LT). Patients with biliary atresia (BA), who underwent LT in Beijing Friendship Hospital from January 2017 to December 2019, were enrolled and divided into non-KP (N-KP) and post-KP (P-KP) groups. The patients in the P-KP group were further divided into early failure (KP-EF) defined by NLST <1 year, medium failure (KP-MF, NLST 1-5 years), and late failure (KP-LF, NLST >5 years) subgroups. Clinical data at baseline and during follow-up were collected. The inverse probability of treatment weighting method was used to evaluate the independent effect of KP and the length of NLST on clinical outcomes. Among 197 patients with BA, the N-KP group accounted for 43 (21.8%), KP-EF 71 (46.1%), KP-MF 59 (38.3%), and KP-LF 24 (15.6%) cases, respectively. The N-KP and KP-EF groups had significantly longer hospitalization and intensive care unit stays after LT. Graft and overall survival rates were 93.0% in the N-KP group and 97.4% in P-KP group, respectively. The mortality rate in the P-KP group were significantly lower compared with that of the N-KP group with a hazard ratio (HR) of 0.2 (P = 0.02). The risks of biliary and vascular complications and cytomegalovirus (CMV) infection after LT were significantly higher in KP-EF group than those in the KP-MF and KP-LF groups (HRs = 0.09, 0.2, and 0.3, respectively; all P < 0.001). The KP significantly improved after LT overall survival. Patients with early native liver failure after KP have significantly higher risks for biliary and vascular complications and CMV infection.

Current and emerging adjuvant therapies in biliary atresia

Following Kasai hepatic portoenterostomy (HPE), most patients with biliary atresia will eventually require liver transplantation due to progressive cirrhosis and liver failure. Preventing liver transplantation, or even delaying eventual liver transplantation, is the key to improving long-term outcomes. This review first examines the commonly used adjuvant therapies in post-HPE biliary atresia and the strength of the evidence supporting these therapies. Next, it examines the evolving frontiers of management through a comprehensive evaluation of both recently completed and ongoing clinical trials in biliary atresia. Promising therapies used in other cholestatic liver diseases with potential benefit in biliary atresia are discussed. Improving post-HPE management is critical to prevent complications, delay liver transplantation, and ultimately improve the long-term survival of patients with biliary atresia.

T-Bet Deficiency Attenuates Bile Duct Injury in Experimental Biliary Atresia

Biliary atresia (BA) is an obstructive neonatal cholangiopathy leading to liver cirrhosis and end stage liver disease. A Kasai portoenterostomy may restore biliary drainage, but most patients ultimately require liver transplantation for survival. At diagnosis, immune cells within the liver of patients with BA demonstrate a T-helper 1 (Th1) inflammatory profile similar to rhesus rotavirus (RRV)-infected mice livers developing BA. The transcription factor Tbx21 (T-bet) is essential for induction of a Th1 immune response in both the adaptive and innate immune system. Here we used animals with targeted deletion of the T-bet gene to determine its role in the progression of BA. Infection of newborn T-bet knockout (KO) pups with RRV resulted in a decreased Th1 inflammatory chemokine/cytokine profile when compared to infected wild-type mice. Analysis of the mononuclear cells profile from T-bet KO mice revealed both a significant decrease in the total number of CD3, CD4, and CD8 T cells and their effector molecules granzyme A, perforin, and FasL. Even though the percentage of T-bet KO mice displaying symptoms of an obstructive cholangiopathy and overall mortality rate was not different compared to wild-type mice, the extrahepatic bile ducts of T-bet KO mice remained patent.

Biliary Atresia/Neonatal Cholestasis: What is in the Horizon?

"Biliary atresia (BA) is a common cause of jaundice in infancy. There is increasing evidence that newborn screening with direct or conjugated bilirubin leads to earlier diagnosis. Although the Kasai portoenterostomy is the primary treatment, there are scientific advances in adjuvant therapies. As pediatric patients transition to adult care, multidisciplinary care is essential, given the complexity of this patient population."

Factors influencing the quality of life in children after biliary atresia treatment

BACKGROUND

Despite surgical treatment, children with biliary atresia (BA) may face many problems which seriously affect their quality of life. However, there is a paucity of studies in China examining the quality of life of these children after BA treatment. This study investigated the current status of the quality of life of children after BA treatment and analyzed the influencing factors so as to provide a scientific basis for the development of targeted interventional measures.

METHODS

From May 1 to May 31, 2021, the STAR questionnaire method was used to conduct cross-sectional surveys in children following BA surgery in the West China Hospital of Sichuan University, China. The basic information questionnaire was used to investigate the general characteristics of the children. The children were also given quality of life questionnaires during follow-up sessions after surgical treatment for BA. In addition, a 12-point health survey was used to assess the physical and mental health of the children's caregivers. Age- and gender-matched healthy children were recruited as controls. Correlation analysis and multiple linear regression equations were established to explore the influencing factors of the quality of life of children after surgery for BA.

RESULTS

After surgery, children with BA experienced significantly lower physical health, emotional function, social function, cognitive function, and quality of life compared to healthy children (P<0.050). Co-existing diseases had a statistically significant impact on the quality of life of children with BA (b=-12.566; t=-2.343; P=0.021), and the caregiver's understanding level of liver transplantation also had a statistically significant impact on the quality of life of these children (b=6.481; t=2.376; P=0.021).

CONCLUSIONS

The quality of life of children after BA surgery was significantly lower than that of age-matched healthy children. Co-existing diseases and the caregiver's understanding level of liver transplantation were the main factors affecting the quality of life of these children.

Long-term outcomes of biliary atresia patients surviving with their native livers

Portoenterostomy (PE) has remained as the generally accepted first line surgical treatment for biliary atresia (BA) for over 50 years. Currently, close to half of BA patients survive beyond 10 years with their native livers, and most of them reach adulthood without liver transplantation (LT). Despite normalization of serum bilirubin by PE, ductular reaction and portal fibrosis persist in the native liver. The chronic cholangiopathy progresses to cirrhosis, complications of portal hypertension, recurrent cholangitis or hepatobiliary tumors necessitating LT later in life. Other common related health problems include impaired bone health, neuromotor development and quality of life. Only few high-quality trials are available for evidence-based guidance of post-PE adjuvant medical therapy or management of the disease complications. Better understanding of the pathophysiological mechanisms connecting native liver injury to clinical outcomes is critical for development of accurate follow-up tools and novel therapies designed to improve native liver function and survival.

The combination of conventional ultrasound and shear-wave elastography in evaluating the segmental heterogeneity of liver fibrosis in biliary atresia patients after Kasai portoenterostomy

OBJECTIVE

To retrospectively assess the value of the combination of conventional ultrasound and shear-wave elastography (SWE) in evaluating the segmental heterogeneity of liver fibrosis in biliary atresia (BA) patients after Kasai portoenterostomy.

METHODS

A total of 35 BA patients with liver segmental deformation were enrolled. The segmental deformation was assessed by conventional ultrasound followed with SWE examinations for evaluating the liver stiffness. Liver biopsy was performed in 11 patients in the region of SWE measurement and liver fibrosis was assessed using the Metavir classification. Aminotransferase to platelet ratio index (APRI) was calculated for comparison. The correlations between serum biochemical tests with SWE values were evaluated. Spearman's rank coefficient test was performed to evaluate the correlation between variables.

RESULTS

The SWE values of the biopsy segments had significant positive correlations with liver fibrosis severity (r = 0.828, p = 0.001), which was better than APRI (r = 0.366, p = 0.242). The levels of bilirubin and transaminase showed significant correlations with the SWE values at hypertrophic segments in all patients (r from 0.336 to 0.576, all p < 0.05).

CONCLUSIONS

Awareness of the segmental heterogeneity of liver fibrosis evaluated by conventional ultrasound and SWE may assist in selecting an appropriate biopsy location and predicting postoperative surveillance for patients with BA.

High Mobility Group Box 1 Release by Cholangiocytes Governs Biliary Atresia Pathogenesis and Correlates With Increases in Afflicted Infants

BACKGROUND AND AIMS

Biliary atresia (BA) is a devastating cholangiopathy of infancy. Upon diagnosis, surgical reconstruction by Kasai hepatoportoenterostomy (HPE) restores biliary drainage in a subset of patients, but most patients develop fibrosis and progress to end-stage liver disease requiring liver transplantation for survival. In the murine model of BA, rhesus rotavirus (RRV) infection of newborn pups results in a cholangiopathy paralleling that of human BA. High-mobility group box 1 (HMGB1) is an important member of the danger-associated molecular patterns capable of mediating inflammation during infection-associated responses. In this study, we investigated the role of HMGB1 in BA pathogenesis.

APPROACH AND RESULTS

In cholangiocytes, RRV induced the expression and release of HMGB1 through the p38 mitogen-activated protein kinase signaling pathway, and inhibition of p38 blocked HMGB1 release. Treatment of cholangiocytes with ethyl pyruvate suppressed the release of HMGB1. Administration of glycyrrhizin in vivo decreased symptoms and increased survival in the murine model of BA. HMGB1 levels were measured in serum obtained from infants with BA enrolled in the PROBE and START studies conducted by the Childhood Liver Disease Research Network. High HMGB1 levels were found in a subset of patients at the time of HPE. These patients had higher bilirubin levels 3 months post-HPE and a lower survival of their native liver at 2 years.

CONCLUSIONS

These results suggest that HMGB1 plays a role in virus induced BA pathogenesis and could be a target for therapeutic interventions in a subset of patients with BA and high HMGB1.

Biliary atresia liver histopathological determinants of early post-Kasai outcome

BACKGROUND

A retrospective chart review of liver histologies in Kasai biliary atresia BA patients operated 1/2017- 7/2019 at our institution was conducted to identify histologic prognostic factors for biliary outcome.

METHODS

Patients with wedge liver biopsies and portal plate biopsies (n = 85) were categorized into unfavorable and favorable outcome, based on a 3-month serum total bilirubin level of <34 μM or mortality. Hepatocellular histologies, presence of ductal plate malformation (DPM) and of large bile duct of ≥ 150 μm diameter size at the portal plate were evaluated.

RESULTS

Total Bilirubin levels> 34 μM correlates with worse 1-year survival. Age at surgery, histologic fibrosis or inflammation does not predict outcome. Potential adverse predictors are severe hepatocellular swelling, severe cholestasis, presence of DPM (n = 24), and portal plate bile duct size < 150 µm (n = 28). In multivariate analyses adjusting for age at Kasai and postop cholangitis, bile duct size and severe hepatocellular swelling remain independent histologic prognosticators (OR 3.25, p = 0.039 and OR 3.26, p = 0.006 respectively), but not DPM.

CONCLUSION

Advanced histologic findings of portal plate bile duct size of <150 µm and severe hepatocellular damage predict poor post-Kasai jaundice clearance and short-term survival outcome, irrespective of Kasai timing.

LEVEL OF EVIDENCE

Level III.

Prognostic and Pathophysiologic Significance of IL-8 (CXCL8) in Biliary Atresia

Interleukin (IL)-8 (CXCL8), a chemokine involved in neutrophil recruitment, has been implicated in ductular reaction and liver fibrogenesis. We studied liver and serum IL-8 expression in a large biliary atresia (BA) cohort and explored its prognostic and pathophysiological potential. IL-8 expression was assessed in liver utilizing quantitative polymerase chain reaction (qPCR), immunohistochemistry and in situ hybridization and in serum using an enzyme-linked immunosorbent assay, among 115 BA patients, 10 disease controls and 68 normal controls. Results were correlated to portoenterostomy (PE) outcomes, biochemical and histological liver injury, transcriptional markers of fibrosis and cholangiocytes, and expression of other related cytokines. IL-8 was markedly overexpressed in liver and serum of BA patients at PE (n = 88) and in serum samples obtained during postoperative follow-up (n = 40). IL-8 expression in the liver was predominantly in cholangiocytes within areas of ductular reaction. Liver IL-8 mRNA expression correlated positively with its serum concentration, bile ductular proliferation, Metavir fibrosis stage, and transcriptional markers of activated myofibroblasts (ACTA2) and cholangiocytes (KRT19). Taken together, IL-8 may mediate liver injury in BA by promoting ductular reaction and associated liver fibrogenesis. Prognostic value of serum IL-8 to predict native liver survival was limited and confined to the postoperative period after PE.

Biomarkers for the diagnosis and post-Kasai portoenterostomy prognosis of biliary atresia: a systematic review and meta-analysis

To evaluate the accuracy of biomarkers for the early diagnosis of biliary atresia (BA) and prognostic stratification after Kasai portoenterostomy (KPE). We conducted a systematic review of PubMed, Web of Science, Embase, Scopus and OVID for English literature reporting BA biomarkers published before August 2020. Screening, data extraction, and quality assessment were performed in duplicate. A total of 51 eligible studies were included in the systematic review, and data from 12 (4182 subjects) were extracted for meta-analysis regarding the following 2 domains: (1) serum matrix metallopeptidase-7 (MMP-7), interleukin33 (IL-33) and γ-glutamyl transferase (GGT) to differentiate BA from non-BA; (2) the aspartate aminotransferase to platelet ratio index (APRi) to predict post-KPE liver fibrosis/cirrhosis. The summary sensitivity, specificity and area under the curve (AUC) of MMP-7 for diagnosing BA were 96%, 91% and 0.9847, respectively, and those of GGT were 80%, 79% and 0.9645, respectively. The summary sensitivity and specificity of IL-33 for diagnosing BA were 77% and 85%, respectively. The summary sensitivity and specificity of APRi for predicting post-KPE liver fibrosis were 61% and 80%, respectively, and the summary sensitivity, specificity and AUC of APRi for predicting post-KPE cirrhosis were 78%, 83% and 0.8729, respectively. Moreover, good evidence was shown in investigations of serum IL-18 and IL-33 in distinguishing BA from healthy controls, serum IL-18 for prognosis of post-KPE persistent jaundice, and serum hyaluronic acid and MMP-7 for prognosis of post-KPE significant liver fibrosis. MMP-7, IL-33 and GGT are useful biomarkers to assist in the diagnosis of BA. APRi might be used to predict post-KPE significant liver fibrosis and cirrhosis. These noninvasive biomarkers can be integrated into the management protocol of BA.

Evolving Up-regulation of Biliary Fibrosis-Related Extracellular Matrix Molecules After Successful Portoenterostomy

Successful portoenterostomy (SPE) improves the short-term outcome of patients with biliary atresia (BA) by relieving cholestasis and extending survival with native liver. Despite SPE, hepatic fibrosis progresses in most patients, leading to cirrhosis and a deterioration of liver function. The goal of this study was to characterize the effects of SPE on the BA liver transcriptome. We used messenger RNA sequencing to analyze global gene-expression patterns in liver biopsies obtained at the time of portoenterostomy (n = 13) and 1 year after SPE (n = 8). Biopsies from pediatric (n = 2) and adult (n = 2) organ donors and other neonatal cholestatic conditions (n = 5) served as controls. SPE was accompanied by attenuation of inflammation and concomitant up-regulation of key extracellular matrix (ECM) genes. Highly overexpressed genes promoting biliary fibrosis and bile duct integrity, such as integrin subunit beta 6 and previously unreported laminin subunit alpha 3, emerged as candidates to control liver fibrosis after SPE. At a cellular level, the relative abundance of activated hepatic stellate cells and liver macrophages decreased following SPE, whereas portal fibroblasts (PFs) and cholangiocytes persisted. Conclusion: The attenuation of inflammation following SPE coincides with emergence of an ECM molecular fingerprint, a set of profibrotic molecules mechanistically connected to biliary fibrosis. The persistence of activated PFs and cholangiocytes after SPE suggests a central role for these cell types in the progression of biliary fibrosis.

Developmental histology of the portal plate in biliary atresia: observations and implications

PURPOSE

The key characteristic of biliary atresia (BA) is obliteration of the extrahepatic bile ducts at the level of the porta hepatis. We aimed to relate the immunohistochemical features of remnant biliary ductules at the porta hepatis with clinical features and outcomes.

METHODS

Samples were immunostained with anti-cytokeratin 20 (CK20), vimentin and alpha-smooth muscle actin (aSMA). Primary outcome was set as clearance of jaundice (bilirubin ≤ 20 μmol/L) following Kasai portoenterostomy (KPE).

RESULTS

Eighty-two cases were classified into syndromic BA (n = 10), cystic BA (n = 7), CMV IgM+ BA (n = 9) and isolated BA (n = 56). CK20 expression was confirmed in 40/82 (49%), and vimentin expression in 19/82 (23%). aSMA was negative in all cases studied. CK20 expression was less common in isolated BA (n = 20/56, 36%) compared to CMV IgM+ BA (n = 8/9, 89%), cystic BA (n = 7/7, 100%) (isolated BA vs non-isolated BA, P = 0.0008). There was no difference in vimentin expression among the sub-groups (isolated BA vs. non-isolated BA; P = 0.39). CoJ was achieved in 52/82 (63%) overall with significant difference depending simply on sub-group [e.g. syndromic BA 9/10 (90%)]. CK20 expression was associated with a diminished rate of CoJ in the entire cohort [CK20+ 32/56 (57%) vs. CK20- 20/26 (77%); P = 0.04]. By contrast no correlation was observed between vimentin expression and CoJ (P = 0.13).

CONCLUSION

CK20+ expression was associated with reduced clearance of jaundice in BA and a trend towards reduced native liver survival.

The usefulness of immunohistochemical staining of bile tracts in biliary atresia

Aim of the study

To assess ductular proliferation (DP) and ductal plate malformation (DPM) in biliary atresia (BA) by means of immunohistochemical staining using cytokeratins CK7 and CK19 and neural cell adhesion molecule (NCAM) antibody CD56.

Material and methods

In 10 cases of BA, liver surgical biopsies obtained at the time of hepatoportoenterostomy were stained with H&E, PAS, Gomori and Azan methods. Immunohistochemical technique was used to outline bile ducts, ductular reaction, reactive bile duct/ductules and DPM by CK7, CK19 and NCAM antibody CD56.

Results

We found fibrosis, bile stasis and mild inflammation in all cases. In the routine staining DP was not seen in 3 cases. The immunohistochemical staining by means of CK19 was helpful in the detection of DP, and allowed it to be demonstrated in all cases. The biliary epithelial cell markers for CD56, CK7, CK19 were used for demonstration of bile duct cell but not hepatocyte alterations in the structure of intrahepatic biliary ducts and different stages of maturation. CD56 as a marker of immature bile ducts was expressed on biliary epithelium of bile ducts and bizarre forms of DPM in 6 cases. The positive expression of CD56 corresponded to the co-localization of CK19 of DPM, but not CK7, to the ductular reaction at the limiting plate of portal tracts. CD7, considered as a marker of DP, also stained ductal hepatocytes and multipotential oval cells, and was a marker of DPM in 3 cases.

Conclusions

Use of CK7, CK19 and CD56 is helpful in BA diagnosis and allows differentiation of the stage of developing bile duct cells according to the expression pattern.

Genetic aspects of biliary atresia etiology

Biliary atresia (BA) is a cholestatic disorder of infancy that is fatal if untreated. Despite years of study the etiology of BA remains unknown. Three etiopathogenic mechanisms may be involved, such as immune dysregulation, environmental factors and genetic susceptibility. Genetic predisposition is being actively studied. Candidate genes associated with BA in certain populations, genes affecting the cholangiocyte cilia function, as well as genes involved in stress responses have been identified. However, the long-term follow-up of twins with BA suggests that genotype is not of paramount importance for the disease development. Both epigenetic patterns and postzygotic somatic mutations may contribute to etiology of the disease. Recently, some evidence is being accumulated on the possible genetic predisposition to certain outcome of Kasai portoenterostomy performed in patients with BA. However, the presence of a number of factors contributing to the development of the disease makes it difficult to identify the genetic markers.

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.

Innate Immunity and Pathogenesis of Biliary Atresia

Biliary atresia (BA) is a devastating fibro-inflammatory disease characterized by the obstruction of extrahepatic and intrahepatic bile ducts in infants that can have fatal consequences, when not treated in a timely manner. It is the most common indication of pediatric liver transplantation worldwide and the development of new therapies, to alleviate the need of surgical intervention, has been hindered due to its complexity and lack of understanding of the disease pathogenesis. For that reason, significant efforts have been made toward the development of experimental models and strategies to understand the etiology and disease mechanisms and to identify novel therapeutic targets. The only characterized model of BA, using a Rhesus Rotavirus Type A infection of newborn BALB/c mice, has enabled the identification of key cellular and molecular targets involved in epithelial injury and duct obstruction. However, the establishment of an unleashed chronic inflammation followed by a progressive pathological wound healing process remains poorly understood. Like T cells, macrophages can adopt different functional programs [pro-inflammatory (M1) and resolutive (M2) macrophages] and influence the surrounding cytokine environment and the cell response to injury. In this review, we provide an overview of the immunopathogenesis of BA, discuss the implication of innate immunity in the disease pathogenesis and highlight their suitability as therapeutic targets.

Quantitative Liver Fibrosis Using Collagen Hybridizing Peptide to Predict Native Liver Survival in Biliary Atresia: A Pilot Study

BACKGROUND/RATIONALE

Biliary atresia (BA) is a cholangiopathy characterized by bile flow obstruction due to destruction of the biliary tree. Without surgical correction with Kasai portoenterostomy (KPE), BA leads to death or liver transplant (LTx). Early-onset, progressive liver fibrosis is a defining characteristic of BA. Collagen hybridizing peptide (CHP) is a synthetic peptide which binds to denatured collagen strands allowing quantification of fibrosis. This technique has not been used on human liver tissue. The aim of this pilot study was to evaluate the utility of CHP as a measurement of quantitative fibrosis to allow earlier survival with native liver prognostication.

RESULTS

We identified 21 patients with wedge liver biopsies available, of which 14 required LTx. No deaths occurred. Patients requiring LTx tended to be girls with a significantly different mean bilirubin (P = 0.002), albumin (P = 0.001), and alanine aminotransferase (P = 0.03) at 3 months post-KPE. By 1 year post-KPE, 50% of patients in the high CHP intensity group required LTx versus 27% in the low CHP. Overall, fibrosis as quantified by CHP at time of KPE was associated with more than 3 times the risk of requiring LTx by 4 years of age (hazard ratio 3.6, 95% confidence interval 1.15-10.93, P = 0.03). When controlling for sex and total bilirubin >2 mg/dL and albumin at 3 months post-KPE, it predicted nearly 7 times the risk of LTx (hazard ratio 6.89, 95% confidence interval 1.38-34.32, P = 0.02).

CONCLUSION

Our results suggest that quantitative assessment of fibrosis at the time of KPE holds promise as an earlier predictor of LTx requirement in BA. A larger study is justified to assess quantitative fibrosis as a BA prognostic tool.

Long Noncoding RNA H19 Contributes to Cholangiocyte Proliferation and Cholestatic Liver Fibrosis in Biliary Atresia

Biliary atresia (BA) is a neonatal liver disease featuring cholestasis and severe liver fibrosis (LF). Despite advances in the development of surgical treatment, lacking an early diagnostic marker and intervention of LF invariably leads to death from end-stage liver disease in the early years of life. We previously reported that knockout of sphingosine 1-phosphate receptor 2 (S1PR2) protected mice from bile duct ligation (BDL)-induced cholangiocyte proliferation and LF. Our recent studies further showed that both hepatic and serum exosomal long noncoding RNA H19 (lncRNAH19) levels are correlated with cholestatic injury in multidrug resistance 2 knockout (Mdr2^-/- ) mice. However, the role of lncRNAH19 in BA progression remains unclear. Here, we show that both hepatic and serum exosomal H19 levels are positively correlated with severity of fibrotic liver injuries in BA patients. H19 deficiency protects mice from BDL-induced cholangiocyte proliferation and LF by inhibiting bile-acid-induced expression and activation of S1PR2 and sphingosine kinase 2 (SphK2). Furthermore, H19 acts as a molecular sponge for members of the microRNA let-7 family, which results in up-regulation of high-mobility group AT-hook 2 (HMGA2), a known target of let-7 and enhancement of biliary proliferation. Conclusion: These results indicate that H19 plays a critical role in cholangiocyte proliferation and cholestatic liver injury in BA by regulating the S1PR2/SphK2 and let-7/HMGA2 axis. Serum exosomal H19 may represent a noninvasive diagnostic biomarker and potential therapeutic target for BA.

MULTIVARIATE ANALYSIS OF BILIARY FLOW-RELATED FACTORS AND POST-KASAI SURVIVAL IN BILIARY ATRESIA PATIENTS

BACKGROUND

Biliary atresia represents the most common surgically treatable cause of cholestasis in newborns. If not corrected, secondary biliary cirrhosis invariably results.

OBJECTIVE

To evaluate, through multivariate analysis, the prognostic factors associated with the presence of biliary flow and survival with the native liver following Kasai portoenterostomy.

METHODS

The study analyzed data from 117 biliary atresia patients who underwent portoenterostomy and had suitable histological material for evaluation. A logistic regression model was used to assess the presence of biliary flow. Survival was investigated through Kaplan-Meier curves and Cox-adjusted models.

RESULTS

One third of patients achieved biliary flow and the median age at surgery was 81 days. Age at surgery, albumin, postoperative complications, biliary atresia structural malformation (BASM), liver architecture, larger duct diameter at porta hepatis, and cirrhosis (Ishak score) were the initial variables for the multivariate analysis. Age at surgery >90 days was the only variable associated with the absence of biliary drainage. Survival analysis revealed that the absence of biliary flow (P<0.0001), age at surgery >90 days (P=0.035), and the presence of BASM (P<0.0001), alone, could predict death or need for liver transplantation. Multivariate analysis demonstrated that the absence of biliary flow (P<0.0001 hazard ratio [HR] 6.25, 95% confidence interval [CI] 3.19-12.22) and the presence of BASM (P=0.014 HR 2.16, 95% CI 1.17-3.99) were associated with lowest survival with the native liver.

CONCLUSION

Age at surgery >90 days was associated with absence of biliary flow. The presence of biliary drainage and the absence of structural malformations are cornerstone features for higher survival rates with the native liver.

Very low bilirubin after portoenterostomy improves survival of the native liver in patients with biliary atresia by deferring liver fibrogenesis

BACKGROUND

Progression of fibrosis and ensuing complications determine the postoperative course of patients operated on for biliary atresia. We evaluated predictors of the progression of fibrosis in the native liver after operative treatment.

METHODS

Among patients whose bilirubin decreased to <34 µmol/L after portoenterostomy (n = 41), predictors of follow-up cirrhosis and the progression of fibrosis were analyzed with logistic regression and survival of their native liver was evaluated with the Kaplan-Meier method. Areas under receiving operating characteristic were used to define optimal cutoffs.

RESULTS

After median follow-up of 5.2 years (interquartile range 1.6-10.2) after portoenterostomy, liver biopsies showed cirrhosis in 53% of patients, and the Metavir stage remained stable or decreased in 38%. The development of cirrhosis was predicted by total or conjugated bilirubin ≥170/120 µmol/L at the time of portoenterostomy (P ≤ .009); normalization of bilirubin within 1.9 months (P = .002); total or conjugated bilirubin ≥ 12.5/7.5 µmol/L (P = .002) and aspartate aminotransferase-to-platelet ratio ≥ 0.55 at 3 months postoperatively (P = .001); and total or conjugated bilirubin ≥ 7.5/2.5 µmol/L (P ≤ .001), aspartate aminotransferase-to-platelet ratio ≥ 0.63 (P = .004), and gamma glutamyl transferase ≥ 266 U/L (P = .007) at 6 months postoperatively. In multiple regression analysis, conjugated bilirubin ≥ 2.5 µmol/L at 6 months increased the risk of cirrhosis 35-fold (P = .020), and other predictors were not predictive. Total or conjugated bilirubin < 12.5/7.5 µmol/L (P ≤ .014), aspartate aminotransferase-to-platelet ratio < 0.55 at 3 months (P = .006), and total or conjugated bilirubin < 7.5/2.5 µmol/L at 6 months postoperatively (P ≤ .014) were the strongest predictors of a stable, nonprogressive fibrosis. Decreases in total or conjugated bilirubin to < 12.5/7.5 µmol/L by 3 months and to < 7.5/2.5 µmol/L by 6 months improved survival of the native liver (log-rank P ≤ .025). Age at follow-up or at portoenterostomy, anatomic type of biliary atresia, use of postoperative steroids, and episodes of cholangitis were unrelated to the progression of fibrosis or the development of cirrhosis (P = not significant).

CONCLUSION

Among patients whose serum bilirubin normalizes after portoenterostomy, its rapid decrease to very low levels prolongs the survival of their native liver by delaying the progression of fibrosis.

Prognostic factors indicating survival with native liver after Kasai procedure for biliary atresia

BACKGROUND

The number of the bile ducts in the portal canal/measured surface area of the portal canal (BDP ratio) indicates prognosis in biliary atresia (BA), as does an elevated cytokeratin 7 positivity percentage (PCK7). We compared these two markers.

METHODS

We reviewed 32 BA cases undergoing Kasai operation from 1976 to 2016 with >5 portal canals in biopsy samples. Group I required liver transplantation or died within a year of operation (n = 8). Group II survived with their native liver (n = 24). We determined the BDP ratio (10²/mm²) and PCK7 (%), subdividing patients into three groups by their age at operation: Group A ≤60 days (n = 6, 1 Group I), 60< Group B ≤90days (n = 16, 5 Group I), Group C >90 days (n = 10, 2 Group I).

RESULTS

PCK7 (%) was 2.71 ± 1.87 in Group I and 4.25 ± 2.56 in Group II (p = 0.13). BDP ratio (10²/mm²) was 1.19 ± 0.424 in Group I and 1.64 ± 0.534 in Group II (p = 0.04). Both markers were higher in Group C than in Group A or B (p < 0.01).

CONCLUSION

The BDP ratio is a better prognostic indicator than PCK7 in BA.

Treatment Policy and Liver Histopathology Predict Biliary Atresia Outcomes: Results after National Centralization and Protocol Biopsies

BACKGROUND

Different treatment policies can influence biliary atresia outcomes, but the pathophysiology of expanding fibrosis occurring even after successful portoenterostomy remains unclear.

STUDY DESIGN

Clearance of jaundice (COJ) (bilirubin <20 μmol/L), native liver survival, and overall survival rates of biliary atresia patients were analyzed before and after national centralization of management, as well as in relation to native liver histopathology of protocol biopsies.

RESULTS

Of the 59 patients, 35 were managed after centralization and received standardized postoperative adjuvant therapy, including corticosteroids. After centralization, age at portoenterostomy decreased from 73 days to 54 days (p = 0.014) and COJ rate increased from 42% to 80% (p = 0.005), 5-year native liver survival increased from 38% to 70% (p = 0.014), and 5-year overall survival increased from 68% to 94% (p = 0.007). High-grade portal inflammation at portoenterostomy predicted COJ (odds ratio 3.66; p = 0.011) and slower fibrosis progression (β = -0.74; p = 0.005). Native liver survival was extended in patients with high-grade portal inflammation (p = 0.002) and in patients whose bilirubin normalized within 3 months (p < 0.001). Portal inflammation and cholestasis reduced only after COJ (p < 0.001), and persisting ductal reaction, reflected by cytokeratin 7-positive proliferating bile ductules and periportal hepatocytes, correlated with follow-up fibrosis (r = 0.454 to 0.763; p < 0.001 to 0.003). Cytokeratin 7 immunopositivity of periportal hepatocytes increased after COJ (p = 0.015) and was the only predictor of follow-up liver fibrosis (β = 0.36; p = 0.002) in multiple regression.

CONCLUSIONS

Biliary atresia outcomes improved significantly after centralization and standardized management. Resolution of cholestasis and reduction of high-grade portal inflammation postoperatively predict slower fibrosis progression and improved native liver survival, and persisting ductal reaction parallels progressive native liver fibrosis despite COJ.

Molecular signature of active fibrogenesis prevails in biliary atresia after successful portoenterostomy

BACKGROUND

In biliary atresia mechanisms of progressive liver injury leading to need of liver transplantation after successful portoenterostomy remain unknown. A better understanding is a prerequisite for development of novel therapies to extend native liver survival, and we aimed to unravel molecular characteristics of liver injury after successful portoenterostomy.

METHODS

Liver biopsies obtained from 28 biliary atresia children during successful portoenterostomy and at median age 3.0 years were studied. Biopsies were analyzed for histology and immunohistochemical expression of collagen 1, myofibroblast marker α-smooth muscle actin, and cytokeratin-7 positive ductal reactions. Hepatic ribonucleic acid (RNA) expression of growth factors and inflammatory cytokines was evaluated. Intestinal failure patients with comparable liver fibrosis and nonfibrotic gallstone patients and donor livers were controls.

RESULTS

After successful portoenterostomy, histologic cholestasis resolved and portal inflammation reduced, while fibrosis along with ductal reactions and overexpression of collagen and α-smooth muscle actin persisted. At follow-up, liver RNA expression of collagen and platelet-derived growth factor was increased, whereas RNA expression of various inflammatory cytokines remained low. Disappearance of periductal α-smooth muscle actin expression after successful portoenterostomy (36% of patients) associated with contracted ductal reactions and reduced progression of fibrosis, collagen accumulation, platelet-derived growth factor RNA expression, and serum levels of bile acids and bilirubin. Fibrosis progressed less rapidly in syndromic than in isolated biliary atresia patients.

CONCLUSION

These findings suggest that instead of inflammation, molecular signature of active fibrogenesis in association with ductal reactions prevails in long-term native liver survivors with biliary atresia. Patients should be stratified for isolated and syndromic disease forms in interventional studies.

Key Histopathologic Features of Liver Biopsies That Distinguish Biliary Atresia From Other Causes of Infantile Cholestasis and Their Correlation With Outcome: A Multicenter Study

The liver biopsy guides diagnostic investigation and therapy in infants with undiagnosed cholestasis. Histologic features in the liver may also have prognostic value in the patient with biliary atresia (BA). We assessed the relative value of histologic features in 227 liver needle biopsies in discriminating between BA and other cholestatic disorders in infants enrolled in a prospective Childhood Liver Disease Research Network (ChiLDReN) cohort study by correlating histology with clinical findings in infants with and without BA. In addition, we reviewed 316 liver biopsies from clinically proven BA cases and correlated histologic features with total serum bilirubin 6 months after hepatoportoenterostomy (the Kasai procedure, HPE) and transplant-free survival up to 6 years. Review pathologists were blinded to clinical information except age. Semiquantitative scoring of 26 discrete histologic features was based on consensus. Bile plugs in portal bile ducts/ductules, moderate to marked ductular reaction, and portal stromal edema had the largest odds ratio for predicting BA versus non-BA by logistic regression analysis. The diagnostic accuracy of the needle biopsy was estimated to be 90.1% (95% confidence interval [CI]: 85.2%, 94.9%), whereas sensitivity and specificity for a diagnosis of BA are 88.4% (95% CI: 81.4, 93.5) and 92.7% (95% CI: 84.8, 97.3), respectively. No histologic features were associated with an elevated serum bilirubin 6 months after HPE, although it (an elevated serum bilirubin) was associated with an older age at HPE. Higher stages of fibrosis, a ductal plate configuration, moderate to marked bile duct injury, an older age at HPE, and an elevated international normalized ratio were independently associated with a higher risk of transplantation.

Value of Gamma-Glutamyl Transpeptidase for Diagnosis of Biliary Atresia by Correlation With Age

OBJECTIVES

The aim of the study was to analyze the value of gamma-glutamyl transpeptidase (GGT) for distinguishing biliary atresia (BA) from non-BA for patients suspected of having neonatal obstructive jaundice by correlation with age.

METHODS

From January 2003 to March 2014, cholangiography and/or surgical exploration were undertaken in 1469 patients with suspicion of having neonatal obstructive jaundice. A total of 1338 patients were diagnosed with BA intraoperatively. Preoperative medical records were compared between BA and non-BA patients.

RESULTS

Preoperative levels of total bilirubin, direct bilirubin, and GGT were significantly higher in the BA group (P < 0.05), whereas the non-BA group had higher alkaline phosphatase levels (P = 0.0003). The area under the receiver operating characteristic curve of total bilirubin, direct bilirubin, GGT, and alkaline phosphatase was 0.584, 0.614, 0.843, and 0.398, respectively. In all age groups (i: 31-60 days; ii: 61-90 days; iii: 91-120 days; iv: ≥121 days), BA groups had higher GGT levels (in IU/L) (i: 725.3 ± 549.9; ii: 927.0 ± 679.8; iii: 1114.3 ± 823.1; iv: 767.5 ± 666.7). The level of GGT in patients with BA younger than 30 days was 834.2 ± 475.3 IU/L. GGT levels had the highest diagnostic value (0.869) in group ii (61-90 days) and the lowest diagnosis value (0.712) in group iv (≥121 days). At a cutoff of >303 IU/L in group ii (61-90 days), GGT had 82.8% sensitivity and 81.6% specificity for the discrimination of BA.

CONCLUSIONS

GGT levels contribute to the diagnosis of BA before 120 days. Age must be considered if using GGT levels as a diagnostic test for BA.

A Prospective Comparison of Noninvasive Methods in the Assessment of Liver Fibrosis and Esophageal Varices in Pediatric Chronic Liver Diseases

GOALS AND BACKGROUND

We compared liver stiffness (LS), the aspartate aminotransferase-to-platelet ratio index (APRi), and the platelet-to-spleen size z score ratio (P/SZC) in the prediction of liver fibrosis and esophageal varices in children.

STUDY

LS, APRi, SZC, and P/SZC were prospectively determined in 99 unselected consecutive children, who underwent liver biopsy for the follow-up of chronic liver disorders. LS was assessed by transient elastography. The spleen size was evaluated as the SD from age-specific and gender-specific normative values. Varices were assessed endoscopically (n=64). Biopsies were staged according to Metavir.

RESULTS

The median patient age was 6.0 (interquartile range, 1.8 to 12.9) years. Underlying diagnoses included intestinal failure (n=31), biliary atresia (n=24), and others (n=44). LS showed the strongest correlation with the fibrosis stage (r=0.639, P<0.001) compared with P/SZC (r=-0.427, P=0.003), APRi (r=0.419, P=0.001), or SZC (r=0.396, P=0.004). LS clearly performed the best in predicting fibrosis with area under the receiver operator curve (AUROC) values of 0.789 [95% confidence interval (CI), 0.698-0.879; P<0.001] for any (Metavir≥1), and 0.831 (95% CI, 0.745-0.918; P<0.001) for significant (Metavir≥2) fibrosis. For the prediction of the presence of esophageal varices, APRi had a higher AUROC of 0.832 (95% CI, 0.730-0.934; P<0.001), when compared with LS, SZC, or P/SZC with AUROCs of 0.818 (95% CI, 0.706-0.930; P<0.001), 0.795 (95% CI, 0.683-0.904; P=0.001), and 0.760 (95% CI, 0.610-0.909; P=0.004), respectively.

CONCLUSIONS

LS performed the best in predicting liver fibrosis, whereas APRi had the highest predictive accuracy for esophageal varices. An LS value over 7.7 kPa identified significant liver fibrosis with high accuracy, whereas low APRi ascertained the absence of esophageal varices.

Diagnosing native liver fibrosis and esophageal varices using liver and spleen stiffness measurements in biliary atresia: a pilot study

BACKGROUND

Biliary atresia commonly leads to liver fibrosis and cirrhotic complications, including esophageal varices.

OBJECTIVE

To evaluate liver and spleen stiffness measurements using acoustic radiation force impulse (ARFI) imaging for diagnosing grade of liver fibrosis and predicting the presence of esophageal varices in patients treated for biliary atresia.

MATERIALS AND METHODS

ARFI imaging of the spleen and native liver was performed in 28 patients with biliary atresia. We studied the relation between ARFI imaging values and liver histology findings (n=22), upper gastrointestinal endoscopy findings (n=16) and several noninvasive test results. Diagnostic accuracy was assessed using receiver operating characteristic curve analyses.

RESULTS

Liver stiffness measurements exhibited a significant difference among the different grades of liver fibrosis (P=0.009), and showed higher values in patients with high-risk esophageal varices than in the other patients (P=0.04). The areas under the receiver operating characteristic curves of liver stiffness measurements for liver fibrosis grades  ≥ F2, ≥F3 and = F4 were 0.83, 0.93 and 0.94, respectively. Patients with high-risk esophageal varices were preferentially diagnosed by the combined liver and spleen stiffness measurements (area under the curve, 0.92).

CONCLUSION

Liver and spleen stiffness measurements using ARFI imaging are potential noninvasive markers for liver fibrosis and esophageal varices in patients treated for biliary atresia.

The limited prognostic value of liver histology in children with biliary atresia

Background and rationale for the study. The aim of the study was to determine the prognostic value of histopathological findings with special care to the severity of liver fibrosis at the moment of hepatoportoenterostomy (HPE) in children with biliary atresia (BA). We performed analysis of 142 wedge liver biopsies taken at the time of HPE. All patients were operated by the same surgical team between 1995 and 2007. According to the outcome 6 months after HPE patients were divided into prognostic groups: group 1-bilirubin level < 2 mg% (n = 65), group 2-bilirubin level > 2 mg% (n = 77). Liver biopsies were re-evaluated according to the extended histopathological protocol and then were compared between the prognostic groups. Survival with native liver (SNL) estimates were performed in regard to severity of liver fibrosis.

RESULTS

Survival with native liver estimates after 2, 5 and 10 years in patients after successful operation were 96%, 91%, 75% vs. 30%, 11%, and 5% if operation failed (p < 0.001). There was no difference between groups in the following variables: fibrosis (p = 0.69), portal inflammation (p = 0.99), lobular inflammation (p = 0.95), cholangiolitis (p = 0.23), accumulation of bile pigments (zone 1:p = 0.49; zone 2:p = 0.51; zone 3:p = 0.48), bile plugs in canaliculi (p = 0.12), bile plugs in ducts (p = 0.32), bilirubinostasis in hepatocytes (p = 0.45), bile ductular proliferation (p = 0.59), ductal plate malformation (p = 0.12), focal necrosis (p = 0.44), giant cell transformation (p = 0.45), haematopoesis (p = 0.52), ductopenia (p = 0.46), microabscesses (p = 0.49), ballooning of hepatocytes (p = 0.08). The actuarial 5/10-year SNL was not dependent on severity of liver fibrosis (log-rank test p = 0.84). The severity of fibrosis corresponded neither with the age at HPE nor with the laboratory findings before operation but increased the risk of portal hypertension.

CONCLUSION

Liver histology at the time of HPE is of limited value in prognosis making in BA.

Increased MMP-7 expression in biliary epithelium and serum underpins native liver fibrosis after successful portoenterostomy in biliary atresia

The molecular mechanisms underlying progressive liver fibrosis following surgical treatment of biliary atresia (BA) remain unclear. Our aim was to address hepatic gene and protein expression and serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) after successful portoenterostomy (PE), and relate them to histological signs of liver injury, clinical follow‐up data and biochemical markers of hepatic function. LIver biopsies and serum samples were obtained from 25 children after successful PE at median age of 3.3 years. Serum MMP concentrations were determined by enzyme‐linked immune sorbent assay. Hepatic gene expression of MMPs and TIMPs was analyzed using real‐time reverse‐transcription PCR. Liver expression of MMP‐7 and cytokeratin‐7 was studied using immunohistochemistry. Despite effective clearance of biochemical and histological cholestasis following PE, BA patients showed increased hepatic gene expression of MMP‐7 (29‐fold, p < 0.001), MMP‐2 (3.1‐fold, p < 0.001), MMP‐14 (1.7‐fold, p = 0.007), and TIMP‐1 (1.8‐fold, p < 0.001), when compared to controls. Similar to a biliary epithelial marker cytokeratin‐7, expression of MMP‐7 localized in biliary epithelium of bile ducts and ductal proliferations and periportal hepatocytes and was increased (p < 0.001) in relation to controls. BA patients had 6‐fold higher serum levels of MMP‐7 (p < 0.001), which correlated positively with hepatic MMP‐7 gene (r = 0.548, p = 0.007) and protein (r = 0.532, p = 0.007) expression. Patients showed a positive correlation between biliary MMP‐7 expression and Metavir fibrosis stage (r = 0.605, p = 0.001) and portal fibrosis grade (r = 0.606, p = 0.001). Neither similarly increased MMP‐7 expression nor correlation with liver fibrosis was observed in patients with intestinal failure‐associated liver disease and comparable Metavir stage. In conclusion, our findings support an unique role of altered hepatic expression of MMP‐7 in the progression of liver fibrosis after successful PE and introduce a potential therapeutic target to pharmacologically extend native liver survival by inhibiting MMP‐7 hyperactivity. Serum MMP‐7 may be a valuable postoperative prognostic tool in BA.

Development and Validation of a Novel Fibrosis Marker in Biliary Atresia during Infancy

OBJECTIVES

Most biliary atresia (BA) patients suffer from liver fibrosis and often require liver transplantation. The aim of this study was to develop and validate a novel fibrosis marker for BA patients aged <1 year-the infant BA liver fibrosis (iBALF) score-subsequent to the previously reported fibrosis marker for BA patients aged ≥1 year.

METHODS

From three institutions for pediatric surgery, BA patients and their native liver histology examinations performed at the age of <1 year were retrospectively identified and assigned to a development cohort (58 patients and 73 examinations) or validation cohort (92 patients and 117 examinations) according to their institutions. Histological fibrosis stages (F0-F4), blood test results, and clinical information at the time of liver histology examination were reviewed. The iBALF score was determined using multivariate ordered logistic regression analysis and was assessed for its associations with histological fibrosis stages.

RESULTS

The iBALF score equation was composed of natural logarithms, including serum total bilirubin level, blood platelet counts, and days of age. The score revealed a strong correlation with fibrosis stage (r=0.80 and 0.73 in the development and validation cohorts, respectively; P<0.001). The areas under the receiver-operating characteristic curves for diagnosing each fibrosis stage were 0.86-0.94 in the development cohort and 0.86-0.90 in the validation cohort (P<0.001), indicating good diagnostic power. In addition, no patient with an iBALF score >6 (equivalent to F4) at the initial surgery survived with their native liver at 1 year of age (n=9).

CONCLUSIONS

The iBALF score that was developed was a good noninvasive marker of native liver fibrosis for BA patients aged <1 year.

APRi predicts native liver survival by reflecting portal fibrogenesis and hepatic neovascularization at the time of portoenterostomy in biliary atresia

BACKGROUND

Aspartate aminotransferase-to-platelet ratio index (APRi) may be useful noninvasive prognostic tool in biliary atresia (BA). We studied whether APRi predicts native liver survival and parallels biochemical and immunohistological signs of liver injury and fibrogenesis at the time of Kasai portoenterostomy (PE).

METHODS

Serum and liver specimens were obtained at PE from 29 BA patients for liver biochemistry including APRi, histology and immunohistochemical analysis of collagen 1, α-SMA and CD34. APRi values were related to native liver survival and other clinical data as well as serum liver biochemistry, liver histology and immunohistochemistry at PE.

RESULTS

Median age at PE was 63 (range 7-141) days and median APRi was 0.92 (0.13-6.39). APRi had strong positive correlations with patient age (r=0.684, p<0.001) and biochemical signs of hepatocyte injury and cholestasis. APRi showed no significant correlations with Metavir (r=0.336, p=0.223) or Ishak (r=0.289, p=0.262) global fibrosis scores nor with liver collagen 1 expression (r=0.260, p=0.222). In contrast, portal fibrosis score (r=0.515, p=0.013), predominantly portal α-SMA expression (r=0.519, p=0.015) and amount CD34-positive microvessels in the centrizonal region (r=0.604, p=0.004) correlated positively with APRi. Patients (n=10) who underwent liver transplantation had significantly higher APRi at presentation (1.34 vs. 0.77, p=0.017) compared to those who survived with native liver (n=19).

CONCLUSIONS

APRi correlates with portal fibrosis, expression of α-SMA and the amount of CD34-positive microvessels, suggesting that APRi predicts native liver survival by reflecting portal myofibroblastic cell activation, fibrogenesis and associated neovascularization.

What Causes Biliary Atresia? Unique Aspects of the Neonatal Immune System Provide Clues to Disease Pathogenesis

Biliary atresia (BA) is the most frequent identifiable cause of neonatal cholestasis and the majority of patients will need liver transplantation for survival. Despite surgical intervention with the Kasai portoenterostomy, significant fibrosis and cirrhosis develops early in life. An increased understanding of what causes this inflammatory fibrosing cholangiopathy will lead to therapies aimed at protecting the intrahepatic biliary system from immune-mediated damage. This review focuses on studies pertaining to the role of the adaptive immune response in bile duct injury in BA, including cellular and humoral immunity. The neonatal presentation of BA begs the question of what are potential modifications of unique aspects of the neonatal immune system that "sets the stage" for the progressive biliary disease? Throughout this article, characteristics of the neonatal immune response are outlined and theories as to how alterations of this response could contribute to the pathogenesis of BA are discussed. These include aberrant Th1 and Th17 responses, deficiencies in regulatory T cells, activation of humoral immunity and autoimmunity. In order to advance our understanding of the etiology of BA, future studies should focus on those unique aspects of the neonatal immune system that have gone awry, as detailed throughout this review.