Epidemiology of Biliary Atresia in Korea

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.

Long-term outcomes of liver transplantation for biliary atresia and results of policy changes: over 20 years of follow-up experience

Objective

Biliary atresia (BA) patients develop chronic liver disease after the Kasai operation and are eventually indicated for liver transplantation (LT). The purposes of this study were to analyze long-term outcomes after LT and risk factors that affect complications to reduce graft failure.

Study design

Overall, 145 pediatric patients who underwent LT between June 1996 and June 2020 after a diagnosis of BA were included. We performed a retrospective analysis of medical records and evaluated patient and graft survival, cumulative incidence of complications, risk factors, and the results of policy changes.

Results

Patient and graft survival rates in over 20 years were 95.8% and 91.0%, respectively. Post-transplantation lymphoproliferative disease was frequently observed in the early period of immunosuppression within the first 1-2 years after LT. The incidence of cholangitis and rejection steadily increased over time. Weight-to-portal vein size was evaluated as a risk factor for cholangitis and bile duct strictures (OR = 12.82, p = 0.006 and OR = 16.54, p = 0.015, respectively). When evaluated using 2013 as a reference point, the split graft indication was expanded and the group that received LT after 2013 had a significantly lower survival over time compared with that of the group that received LT before 2013 (p = 0.006).

Conclusion

This study revealed time differences in prevalence of complications. The evaluation of weight-to-duct or vessel size is a more important factor in considering complications than the graft-to-recipient weight ratio. Survival outcomes may have been altered by a policy change that affects the donor type ratio in transplantation.

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.

Prognostic Factors Related to In-hospital Death in Children with Biliary Atresia: Analysis of a Nationwide Inpatient Database

BACKGROUND AND AIMS

Patients with biliary atresia (BA) are prone to hepatic decompensation, which might eventually lead to death. This study aimed to identify the possible risk factors affecting in-hospital death in BA patients in China.

METHODS

We collected data from the Hospital Quality Monitoring System, a national inpatient database. All patients aged up to 2 years old with a diagnosis of BA were included. The subjects were divided to three groups, including Kasai portoenterostomy (KP), liver transplantation (LT), and no surgery. Logistic regression with Firth's method was performed to identify potential influencing variables associated with in-hospital death.

RESULTS

During the year 2013 to 2017, there were 14,038 pediatric admissions with a diagnosis of BA. The proportion of in-hospital death in pediatric BA admissions was 1.08%. Compared with patients under six months, there was a higher risk of in-hospital death for children aged six months to 1 year and 1-2 years old. Clinical signs, including cirrhosis, variceal bleeding, and hepatic encephalopathy, were significantly associated with the risk of in-hospital death. In no surgery group, compared to those in Beijing and Shanghai, BA patients admitted in other districts had a lower risk of in-hospital death (OR=0.39, 95% CI: 0.21, 0.70). However, in the LT group, patients admitted in other districts had a higher risk of in-hospital death (OR=9.13, 95% CI: 3.99, 20.87).

CONCLUSIONS

In-hospital survival remains unsatisfactory for pediatric BA patients with severe complications. Furthermore, more resources and training for BA treatment, especially LT, are essential for districts with poor medical care in the future.

Incidence of Isolated Biliary Atresia during the COVID Lockdown in Europe: Results from a Collaborative Project by RARE-Liver

BACKGROUND

Biliary atresia (BA) is a rare cholangiopathy where one of the proposed aetiological mechanisms is an infectious viral trigger. Coronavirus disease-19 (COVID) lockdown restrictions were implemented to reduce the transmission of infections. Strictness of lockdown varied across European countries. This study aimed to investigate if there was an association between strictness of lockdown and change in isolated BA (IBA) incidence in Europe.

METHODS

We approached European centres involved in the European Reference Network RARE-LIVER. We included IBA patients born between 2015 and June 2020. We calculated the number of IBA patients born per centre per month. The Stringency Index (SI) was used as lockdown strictness indicator. The association between percentage change of mean number of IBA patients born per month and the SI was assessed.

RESULTS

We included 412 IBA patients from thirteen different centres. The median number of patients per month did not change: 6 (1-15) pre-lockdown and 7 (6-9) during lockdown (p = 0.34). There was an inverse association between SI and percentage change in IBA (B = -0.73, p = 0.03). Median age at Kasai portoenterostomy (days) did not differ between time periods (51 (9-179) vs. 53 (19-126), p = 0.73).

CONCLUSION

In this European study, a stricter COVID-lockdown was seemingly accompanied by a simultaneous larger decrease in the number of IBA patients born per month in the lockdown. Results should be interpreted with caution due to the assumptions and limitations of the analysis.

[Overview of Biliary Atresia]

Biliary atresia is a progressive, idiopathic, obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction in the neonatal period. It is the most common indication for liver transplantation in children. If untreated, progressive liver cirrhosis leads to death by two years of age. Nowadays, more than 90% of biliary atresia patients survive into adulthood with the development of Kasai portoenterostomy and liver transplantation technology. Early diagnosis is critical since the success rate of the Kasai portoenterostomy decreases with time. This study comprehensively reviews the recent advances in the etiology, classification, prevalence, clinical manifestations, treatment, and prognosis of biliary atresia.

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.

The Epidemiology of Biliary Atresia: Exploring the Role of Developmental Factors on Birth Prevalence

OBJECTIVE

To identify key epidemiologic factors relevant to fetal development that are associated with biliary atresia.

STUDY DESIGN

This population-based registry study examined infants born in Texas between 1999 and 2014. Epidemiologic data relevant to fetal development were compared between cases of biliary atresia identified in the Texas Birth Defects Registry (n = 305) vs all live births (n = 4 689 920), and Poisson regression was used to calculate prevalence ratios (PRs) and 95% CIs.

RESULTS

The prevalence of biliary atresia over the study period was 0.65 per 10 000 live births. Biliary atresia was positively associated with female sex (adjusted PR, 1.68; 95% CI, 1.33-2.12), delivery before 32-37 weeks of gestation (adjusted PR, 1.64; 95% CI, 1.18-2.29), delivery before 32 weeks of gestation (adjusted PR, 3.85; 95% CI, 2.38-6.22), and non-Hispanic Black vs non-Hispanic White maternal race/ethnicity (adjusted PR, 1.54, 95% CI, 1.06-2.24), while biliary atresia was inversely associated with season of conception in the fall relative to spring (adjusted PR, 0.62; 95% CI, 0.45-0.86). In addition, biliary atresia was associated with maternal diabetes (adjusted PR, 2.34; 95% CI, 1.57-3.48), with a stronger association with pregestational diabetes compared with gestational diabetes. In subgroup analyses, these associations were present in isolated biliary atresia cases that do not have any additional birth defects.

CONCLUSIONS

Biliary atresia is associated with multiple factors related to fetal development, including pregestational maternal diabetes, female sex, and preterm birth. These associations also were observed in isolated cases of biliary atresia without other malformations or laterality defects. Our results are consistent with early life events influencing the pathogenesis of biliary atresia, and support further studies investigating in utero events to better understand etiology and time of onset.

Biliary Atresia in 2021: Epidemiology, Screening and Public Policy

Biliary atresia (BA) is a rare newborn liver disease with significant morbidity and mortality, especially if not recognized and treated early in life. It is the most common cause of liver-related death in children and the leading indication for liver transplantation in the pediatric population. Timely intervention with a Kasai portoenterostomy (KPE) can significantly improve prognosis. Delayed disease recognition, late patient referral, and untimely surgery remains a worldwide problem. This article will focus on biliary atresia from a global public health perspective, including disease epidemiology, current national screening programs, and their impact on outcome, as well as new and novel BA screening initiatives. Policy challenges for the implementation of BA screening programs will also be discussed, highlighting examples from the North American, European, and Asian experience.

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.

Immune Characteristics in Biliary Atresia Based on Immune Genes and Immune Cell Infiltration

BACKGROUND

Biliary atresia (BA) is a serious biliary disease in infancy. Jaundice is the most visual and prominent symptom, and it mainly involves bile duct cells leading to the loss of intrahepatic and extrahepatic bile ducts. If left untreated, it will eventually progress to liver cirrhosis. The pathogenesis of BA is not clear, and it is now generally accepted that BA is an autoimmune disease. However, few studies have revealed the infiltration of immune cells in the liver of BA from a global perspective. We used liver tissue sequencing data to predict the infiltration and relative content of immune cells in BA.

METHODS

The BA datasets GSE46960, GSE15235, and GSE84044, and patient information were downloaded from the Gene Expression Omnibus (GEO) database. After batch normalization, the differentially expressed immune genes (DE-IGs) in BA liver, normal liver, and hepatitis B liver were analyzed with the cut-off value of |log₂fold change (log₂FC)| >1 and false discovery rate (FDR) <0.05. CIBERSORT software was used to predict the proportions of 22 immune cells in all samples of the datasets.

RESULTS

73 DE-IGs have been screened out between BA and normal tissue; among them, 20 genes were highly expressed and another 53 were expressed at a low level. A total of 30 DE-IGs existed between inflammation and fibrosis livers of BA, and all of them were expressed at low levels in fibrosis livers of BA. In GO term analysis, these DE-IGs were mainly associated with the MHC protein complex, cytokine, chemokine activity, and MHC-II receptor activity. In KEGG pathway analysis, the DE-IGs were mainly enriched in pathways of Th1 and Th2 cell differentiation, Th17 cell differentiation, IL-17 signaling pathway, Toll-like receptor signaling pathway, TNF signaling pathway, and autoimmune diseases. There were significant differences in immune infiltration among different pathological types of BA, and there were also obvious differences in immune infiltration of hepatitis B as a disease control of BA.

CONCLUSION

Based on immune genes and immune cell infiltration, this study reveals the immune characteristics of BA from a global point of view, which provides a new perspective for understanding the pathogenesis of BA and provides a direction for the diagnosis and treatment of BA.

Epidemiological characteristics and risk factors of biliary atresia: a case-control study

OBJECTIVES

Biliary atresia (BA) is regarded as a serious neonatal hepatobiliary disease, and its aetiology and pathogenesis remain unclear. Epidemiological studies are limited, especially for the data from China. This study aims to explore risk factors of BA and provide new evidence to improve understanding of its aetiology.

DESIGN

This is a case-control study from 1 January 2015 to 31 December 2016.

SETTING

Cases were consecutively recruited from an urban tertiary care academic children's hospital in Shanghai, China, while the controls were recruited from a community hospital in Shanghai through a random sampling system.

PARTICIPANTS

721 patients suspected for BA who planned to take the diagnostic surgery were enrolled preoperatively. 613 were diagnosed with BA and recruited into the case group. Meanwhile, 688 infants without any observed major congenital anomalies or jaundice were enrolled. Finally, 594 valid questionnaires from the case group and 681 from the control group were obtained.

PRIMARY AND SECONDARY OUTCOME MEASURES

Standardised questionnaires were used for data collection. Multivariate logistic regression analysis was performed to evaluate associations reported as ORs and precision, by adjusting covariates.

RESULTS

Anxiety or stress during pregnancy was strongly associated with increased risk of BA (OR 8.36 (95% CI: 4.08 to 17.15); p<0.001), respectively. Lower birth weight, fathers from ethnic minorities of China, older age of fathers, lower income of parents, and exposure to infection, diseases and medication during pregnancy all made differences.

CONCLUSIONS

Social factors including the educational and economic background and its related anxiety and stress during pregnancy might be noticed in the occurrence of BA. Maternal infections during pregnancy in the prevalence of BA were demonstrated.

TRIAL REGISTRATION NUMBER

ChiCTR-IPR-15005885.

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."

A Higher Incidence of Isolated Biliary Atresia in Rural Areas: Results From an Epidemiological Study in The Netherlands

OBJECTIVES

Environmental factors may be involved in the pathogenesis of biliary atresia (BA). This epidemiological study aimed to analyze the relationships between the incidence of BA, the incidence of confirmed viral or bacterial infections and population density, and geographical and temporal clustering of BA in the Netherlands.

STUDY DESIGN

Correlations between the monthly incidence of BA and the number of confirmed infections were assessed. BA incidence per province was calculated and compared to the province with highest population density. Birthplaces were classified as rural or urban. Temporal clustering of month of birth and month of conception were analyzed. We performed analyses for isolated BA (IBA) and syndromic BA (SBA) separately. Chi2, logistic regression, and Walter and Elwood test were used.

RESULTS

A total of 262 IBA and 49 SBA patients, born between 1987 and 2018, were included. IBA incidence correlated to the number of confirmed infections of, for example, Chlamydia trachomatis (R = 0.14; P = 0.02) and adenovirus (R = 0.22; P = 0.005). We observed a higher incidence of IBA (0.75/10,000; odds ratio [OR] = 1.86; P = 0.04) and SBA (0.27/10,000; OR = 6.91; P = 0.001) in Groningen and a higher incidence of SBA in Gelderland (0.13/10,000; OR = 3.35; P = 0.03). IBA incidence was 68% higher in rural (0.67/10,000) versus urban areas (0.40/10,000) (P = 0.02). The estimated month of conception of patients with SBA clustered in November (85% increase compared to average SBA incidence [0.09/10,000; P = 0.04]).

CONCLUSIONS

IBA incidence correlated weakly with national confirmed infections. IBA and SBA incidence varied geographically in the Netherlands. IBA incidence was higher in rural than in urban areas, which may be explained decreased exposure to pathogens. Our results provide support for a role of environmental factors in the pathogenesis of IBA.

Neonatal liver disease

Neonatal liver disease encompasses many diagnoses, including structural and genetic aetiologies. Many have significant health implications requiring long-term specialist treatment including liver transplantation. Jaundice is a common presenting feature. The ability of health-care professionals to differentiate neonatal liver disease from benign diagnoses such as physiological jaundice is very important. Persistent (more than 2 weeks) of conjugated jaundice always warrants investigation. Severe unconjugated jaundice (requiring prolonged phototherapy) should also be promptly investigated. Recent advances in genomics have enabled previously elusive, precise diagnoses in some patients with neonatal liver disease. This review paper discusses the commoner causes, with a focus on early detection and need for referral to paediatric liver services.

Inflammation Drives MicroRNAs to Limit Hepatocyte Bile Acid Transport in Murine Biliary Atresia

BACKGROUND

Biliary atresia (BA) is an inflammatory pediatric cholangiopathy with only surgical means for treatment. Many contributors to bile acid synthesis and transport have previously been reported to be downregulated in patients with BA; yet, the driving factors of the abnormal bile acid synthesis and transport in regard to BA have not been previously studied.

MATERIALS AND METHODS

Wild type or Ig-α^-/- mice were injected with salt solution (control) or rotavirus on day of life 0, and analyses were performed on day of life 14. The mRNA levels of bile acid transporters/nuclear receptors and liver microRNAs (miRNAs) were compared between groups. A mouse hepatocyte cell line was used to examine the effects of innate cytokines on miRNA levels and bile acid transporter/nuclear receptor expression and miRNAs on bile acid transporter/nuclear receptor expression.

RESULTS

BA mice had significantly increased mRNA expression of innate cytokines and miRNAs known to bind bile acid transporters/nuclear receptors (miRNAs -22-5p, -34a-5p, and -222-3p) and decreased mRNA expression of bile acid transporters and nuclear receptors. In vitro, TNF-α and IL-1β decreased BSEP and CYP7A1 while increasing miRNA-34a-5p and miRNA 222-3p. LXR, SHP, CYP7A1, NTCP, and MRP2 were decreased by miRNA-34a-5p, whereas miRNA-222-3p decreased NTCP and MRP4. TNF-α and IL-1β increased expression of miRNAs 34a-5p and 222-3p and these miRNAs then decrease expression of multiple bile acid transporters and nuclear receptors.

CONCLUSIONS

Loss of bile acid transporters increases hepatotoxicity via bile acid retention. Therapeutic agents that increase bile acid transport or nuclear receptor functioning should be investigated in BA.

Biliary atresia: East versus west

Biliary atresia (BA) is a common cause of surgical jaundice during the neonatal period. It is currently considered as a spectrum of diseases with a common final pathology characterized by obliteration of the extrahepatic biliary tract and the absence of normally branching intrahepatic ducts. Though it is a global disease that can be found in all ethnicities there are some clear differences between BA arising in the East and the West. This is likely to be related to different genetic, environmental and cultural factors. BA is more frequently found in Far Eastern infants (both Chinese and Japanese) though the syndromic associations are much less common. Many Eastern countries have national screening programmes not seen in the West possibly due to debate over its cost effectiveness in countries where incidence is low. Kasai portoenterostomy (KPE) is considered as the primary treatment of BA but its outcome still remains unsatisfactory across the region. Given the complexity of BA, it is unlikely that strategic advances could be made by the sole effort of individual countries and we believe that collaboration between the East and West is the way forward.

Predicting variceal bleeding in patients with biliary atresia

Background/aims: Variceal bleeding is the main cause of morbidity and mortality in children with portal hypertension and biliary atresia. The aim of this study is to predict high-risk varices by analyzing various clinical factors, thus improve prognosis of patients with biliary atresia.Methods: A total of 157 patients with biliary atresia who underwent Kasai portoentrostomy were enrolled in a single center. Clinical data including laboratory values, endoscopic findings and values of transient elastography (FibroScan^®) were analyzed retrospectively.Results: The bleeding group and the non-bleeding group showed statistically significant differences in several variables; The FibroScan^® value (HR 1.05, 95% CI (1.03-1.07), p  <  .01) was higher in the bleeding group. The bleeding group had values of lower albumin after 3 months of operation (HR 0.28, 95% CI (0.11-0.73), p  =  .01), higher bilirubin after 3 months of operation (total bilirubin: HR 1.18, 95% CI (1.04-1.33), p  =  .01), (direct bilirubin: HR 1.21, 95% CI (1.05-1.41), p  =  .01). Gastric varix (HR 4.10, 95% CI (1.62-10.36), p  <  .01) was more frequent in the bleeding group. And the presence of red sign was also predictive of bleeding. The FibroScan^® cut-off value with the predictive power of bleeding was 31.5 kPa (HR 7.7, 95% CI (3.36-17.73), p  <  .01).Conclusions: Several clinical factors including high value of transient elastography (FibroScan^®), gastric varix or red sign of endoscopy, and low albumin or high bilirubin values after 3 months of Kasai operation can be useful in predicting variceal bleeding in patients with biliary atresia.

Serum MMP-7 in the Diagnosis of Biliary Atresia

BACKGROUND

The overlapping features of biliary atresia (BA) and other neonatal cholestasis with alternative causes (non-BA) have posed challenges for diagnosis. Matrix metalloproteinase-7 (MMP-7) has been reported to be promising in diagnosing BA. We aimed to validate the diagnostic accuracy of MMP-7 for BA in a large population sample.

METHODS

We enrolled 288 patients with neonatal obstructive jaundice from March 2017 to October 2018. Serum MMP-7 levels were measured by using an enzyme-linked immunosorbent assay. Receiver operating characteristic curves were constructed, and decision curve analysis was done. A Pearson correlation coefficient test was conducted to assess the correlation between MMP-7 levels and other characteristics.

RESULTS

The median serum MMP-7 levels were 38.89 ng/mL (interquartile range: 22.96-56.46) for the BA group and 4.4 ng/mL (interquartile range: 2.73-6.56) for the non-BA group (P < .001). The area under the receiver operating characteristic curve value was 0.9829 for MMP-7, and the sensitivity, specificity, positive predictive value, and negative predictive value were 95.19%, 93.07%, 97.27%, and 91.43%, respectively, at a cutoff value of 10.37 ng/mL. When MMP-7 was combined with γ glutamyl transferase, the diagnostic accuracy was slightly improved without significance when compared with MMP-7 alone and had an area under the curve of 0.9880 (P = .08). Decision curve analysis also showed potential for MMP-7 to be used for clinical applications. A significant correlation was found with fibrosis stage from liver biopsy (R = 0.47; P < .001).

CONCLUSIONS

MMP-7 demonstrated good accuracy in diagnosing BA and holds promise for future clinical application. Furthermore, its correlation with liver fibrosis indicated its potential use as a therapeutic target or prognostic biomarker.

Biliary atresia combined with progressive familial intrahepatic cholestasis type 3: A case report and review of the literature

RATIONALE

Neonatal cholestasis is one of the most serious diseases in infancy. Progressive familial intrahepatic cholestasis (PFIC) is a disease that leads to intrahepatic cholestasis. It is one of the common causes of neonatal cholestasis in addition to biliary atresia (BA). The differential diagnosis of neonatal cholestasis is clinically challenging for pediatricians.

PATIENT CONCERNS

A 4-month-old female presented with severe jaundice, pruritus, and pale stool for 20 days. Abnormally strong echoes near the portal area, an abnormally small gallbladder with an irregularly stiff wall, and splenomegaly were identified on abdominal ultrasound. Blood tests showed elevated alanine aminotransferase, total bilirubin, conjugated bilirubin, gamma-glutamyltranspeptidase, and total bile acid levels.

DIAGNOSIS

Intraoperative cholangiography showed BA. ABCB4 gene mutation IVS13+6G>A/G was confirmed by genetic testing. The patient was diagnosed with BA combined with PFIC3.

INTERVENTIONS

Kasai portoenterostomy and ursodeoxycholic acid were used for treatment.

OUTCOMES

Her clinical symptoms and blood tests improved gradually. No recurrence was noted during 1 year of follow-up.

LESSONS

Additional examinations, such as genetic testing, should be considered in patients with BA who had refractory jaundice after Kasai portoenterostomy in order to exclude intrahepatic cholestasis.

Genetics in biliary atresia

PURPOSE OF REVIEW

Biliary atresia is a poorly understood deadly disease. Genetic predisposition factors are suspected albeit not firmly established. This review summarizes recent evidence of genetic alterations in biliary atresia.

RECENT FINDINGS

Whole-genome association studies in biliary atresia patients identified four distinct predisposition loci with four different genes potentially involved in the disease occurrence. Variations in these genes were searched for, but none were found in patients with biliary atresia suggesting complex mechanisms.

SUMMARY

Despite decades since its description and decades of intensive researches, cause of biliary atresia disease remains enigmatic. The inheritance of biliary atresia is not Mendelian. Genetic predisposition factor is one of the explored fields to explain biliary atresia pathogenicity. Biliary atresia has been associated with several inborn syndromes, chromosome anomalies, and gene polymorphisms in specific populations. Four predisposition loci encompassing genes relevant to the disease have been identified, but no pathogenic variations were found in biliary atresia patients. Few reported cases of isolated biliary atresia manifestation in the context of known genetic diseases suggest coincidental findings. Alternatives to classic genetic alterations are proposed to explain genetic predisposition in biliary atresia including noncoding and epigenetic factors. Biliary atresia is most likely related to complex traits making its genetic exploration challenging.

A periodic comparison of the survival and prognostic factors of biliary atresia after Kasai portoenterostomy: a single-center study in Korea

PURPOSE

We explored the chronologic changes in prognostic factors and clinical outcomes of Kasai portoenterostomy (KPE) for biliary atresia (BA).

METHODS

Patients undergoing KPE between 1997 and 2016 were analyzed retrospectively. Ninety-two consecutive patients who underwent KPE from 1997 to 2006 (Era 1) were compared with 150 patients who underwent KPE from 2007 to 2016 (Era 2) for clinical outcomes and prognostic factors.

RESULTS

The jaundice clearance rate increased by 8.8% (66.7% vs. 75.5% for Eras 1 and 2, respectively, p = 0.180), and the 5-year native liver survival (NLS) rate improved slightly (62.5% vs. 64.0% for Eras 1 and 2, respectively, p = 0.617) in Era 2. The hazard ratio for age at KPE (≥ 90 days) with regard to 5-year NLS and the odds ratio for age at KPE (< 90 days) with regard to jaundice clearance were both lower in Era 2 than in Era 1 (1.95 vs. 2.25 and 2.67 vs. 5.21, respectively).

CONCLUSION

The clinical outcomes improved over a period in a single surgeon's practice. We demonstrated that the impact of age at the time of KPE on operative outcomes became less significant over time with the increase in the single surgeon's experience and improvement in medical treatment for BA.

No association between month of birth and biliary atresia in a country with tropical climate

AIM

Children with biliary atresia (BA) born in countries with temperate climate showed month-of-birth (MoB) predilection during cooler months. To date, no study on the MoB-BA association has been performed in a tropical country. Our aim was to define MoB variation in children with BA in a tropical country.

METHODS

We studied 150 children diagnosed with BA between January 1996 and April 2015 at a teaching hospital. MoB was defined by two categories based on the precipitation: rain and dry, and three categories based on the air temperature: high, average and low. We applied the country's population data on the number of births in each period as the expected proportions of birth.

RESULTS

A slightly higher proportion of BA children was born in the rainy months (52.7%); however, the difference was not significant compared to the general population's birth (P = 0.87). For the MoB based on the air temperature, no statistically significant difference was noted. Males with BA seemed to have a greater MoB variation compared to females, but this did not reach statistical significance.

CONCLUSION

We could not find an association between MoB and BA in a tropical country. Multinational studies may aid in understanding the MoB-BA association in the tropical countries.

Ethnic variation in the incidence of biliary atresia correlates with the frequency of the most prevalent haplotype in its population

The cause of biliary atresia (BA) remains an enigma. However, an ethnic diversity in the incidence of BA is so unique that anthropological approach may provide some etiopathogenetic implications in the disease mechanism. We previously reported that an association of maternal microchimerism (MMc) in BA and a significant compatibility of HLA-A between the patient with BA and their mother. Across the 10 countries (Japan, South Korea, Taiwan, Philippines, New Zealand (Maori population), UK, France, Germany, Norway, and Sweden), we determined the frequency of the most prevalent HLA haplotypes of each country from Allele Frequency Database and found that it was significantly correlated with the incidence of BA of the respective country (p = 0.0126). This observation better fits the MMc theory as an etiopathogenesis, that is, maternal effector cells are likely to migrate into the fetus in a relatively homogenous population and may damage the developing bile duct structure and portal vein endothelium, depending on materno-fetal tolerance and immunity.

Direct hyperbilirubinemia in infants with congenital heart disease

BACKGROUND

The association between congenital heart disease (CHD) and infantile cholestasis, a key finding for the diagnosis of biliary atresia (BA), has not been previously investigated. The aim of this study was therefore to investigate the characteristics of direct hyperbilirubinemia (D-HB) in infants with CHD.

METHODS

All neonates admitted to the present hospital and diagnosed with CHD in 2015 and 2016 were included. D-HB (direct bilirubin ≥ 2.0 mg/dL) at ≤60 days of age and other clinical parameters were retrospectively reviewed. Statistical analysis according to presence of D-HB was performed using chi-squared test or Wilcoxon rank sum test.

RESULTS

Seventy-six patients (M:F, 36:40) were included in this study. CHD consisted of ventricular septal defect in 17, patent ductus arteriosus in 10, and other in 49. Thirteen patients (17.1%) had D-HB at ≤60 days of age. Resolution of D-HB (DB < 2.0 mg/dL) occurred in 10 of the 13 patients during the hospital stay, and this occurred in ≤7 days in eight of the 10 patients. Sex, gestational age, birthweight, chromosomal anomalies, need for Fontan operation for CHD repair, and/or cardiac operation were not associated with D-HB at ≤60 days of age.

CONCLUSION

While D-HB was frequently observed in infants with CHD, the majority of D-HB cases resolved spontaneously in ≤1 week. Neonatal clinical parameters or CHD status was not predictive of D-HB. D-HB lasting >1 week in infants with CHD should be evaluated for the cause.