Immune-mediated cholangiopathies in children: the need to better understand the pathophysiology for finding the future possible treatment targets

Cholangiopathies are defined as focal or extensive damage of the bile ducts. According to the pathogenetic mechanism, it may be immune-mediated or due to genetic, infectious, toxic, vascular, and obstructive causes. Their chronic evolution is characterized by inflammation, obstruction of bile flow, cholangiocyte proliferation, and progression toward fibrosis and cirrhosis. Immune-mediated cholangiopathies comprise primary sclerosing cholangitis (PSC), autoimmune cholangitis and IgG4-associated cholangitis in adults and biliary atresia (BA), neonatal sclerosing cholangitis (NSC) in children. The main purpose of this narrative review was to highlight the similarities and differences among immune-mediated cholangiopathies, especially those frequent in children in which cholangiocyte senescence plays a key role (BA, NSC, and PSC). These three entities have many similarities in terms of clinical and histopathological manifestations, and the distinction between them can be hard to achieve. In BA, bile duct destruction occurs due to aggression of the biliary cells due to viral infections or toxins during the intrauterine period or immediately after birth. The consequence is the activation of the immune system leading to severe inflammation and fibrosis of the extrahepatic biliary tract, lumen stenosis, and impairment of the biliary flow. PSC is characterized by inflammation and fibrosis of intra- and extrahepatic bile ducts, leading to secondary biliary cirrhosis. It is a multifactorial disease that occurs because of genetic predisposition [human leukocyte antigen (HLA) and non-HLA haplotypes], autoimmunity (cellular immune response, autoantibodies, association with inflammatory bowel disease), environmental factors (infections or toxic bile), and host factors (intestinal microbiota). NSC seems to be a distinct subgroup of childhood PSC that appears due to the interaction between genetic predisposition (HLA B8 and DR3) and the disruption of the immune system, validated by elevated IgG levels or specific antibodies [antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA)]. Currently, the exact mechanism of immune cholangiopathy is not fully understood, and further data are required to identify individuals at high risk of developing these conditions. A better understanding of the immune mechanisms and pathophysiology of BA, NSC, and PSC will open new perspectives for future treatments and better methods of preventing severe evolution.

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."

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.

Efficacy and safety of Yinchen Sini decoction in treating biliary atresia patients after Kasai portoenterostomy: A systematic review and meta-analysis protocol

BACKGROUND

Biliary atresia (BA) is a neonatal obstructive biliary tract disease in which the intrahepatic and extrahepatic bile ducts are obstructed and can lead to congenital biliary atresia of cholestatic cirrhosis and eventually liver failure. It has been confirmed that the Kasai portoenterostomy is an effective treatment for BA. But most patients still face complications, such as cholangitis and liver fibrosis. Yinchen Sini decoction (YCSND), a traditional herbal formula, is used as a treatment for BA after Kasai portoenterostomy. And it is supported that YCSND can improve jaundice and liver fibrosis through multiple targets and pathways. Based on the published literature, this study aims to evaluate the current situation in the treatment of BA in children with YCSND.

METHODS

The following databases will be searched until October 2018: PubMed, The Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese biomedical literature database (CBM), Wan Fang Database, Chinese Scientific Journals Database (VIP) and other sources such as Hand searching, Conference proceeding, International Clinical Trials Registry Platform and Chinese Clinical Trials Registry. All randomized controlled trials (RCTs) of YCSND or related formula as a treatment for postoperative patients of Kasai portoenterostomy for BA will be collected. Data extraction and risk of bias assessments will be carried out by 2 verifiers independently. The risk of bias will be evaluated through the Cochrane risk of bias tool. Review Manager software (RevMan V.5.3.0) and STATA 15 will be used for statistical analyses.

RESULTS

This study will provide a high-quality synthesis of current evidence of YCSND in treating children undergoing Kasai portoenterostomy for BA from several aspects.

CONCLUSION

The conclusion of the meta-analysis will offer evidence for deciding whether YCSND is an effective measure for children undergoing Kasai portoenterostomy for BA.

ETHICS AND DISSEMINATION

Not only will this systematic review be published in a peer-reviewed journal, but it will also be propagated electronically and in print. The review will bring patients benefit and provide practitioners reference in the fields of conventional medicine.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD 42018111321.

Current management of long-term survivors of biliary atresia: over 40 years of experience in a single center and review of the literature

INTRODUCTION

Owing to several therapeutic advancements, more patients with biliary atresia now survive into adulthood while retaining their native liver. However, the optimal strategy for long-term management of such patients remains unclear.

METHODS

Aiming to establish the current management strategies, we reviewed previous reports of long-term outcome of BA who underwent surgery at our institution as well as the relevant literature, focusing particularly on the treatment of late complications.

RESULTS

Approximately 30-40% of long-term survivors of biliary atresia who retain their native liver exhibit late sequelae such as cholangitis and portal hypertension. Early and appropriate intervention with Kasai portoenterostomy is essential for ensuring long-term survival with good quality of life. In our hospital, the current standard for Kasai portoenterostomy involves dissecting the fibrous remnants along the porta hepatis, just on the level of the liver capsule. Cholangitis is an important late complication in biliary atresia, and the possibility of mechanical obstruction of the biliary drainage route or deformity of the intrahepatic bile ducts with or without gallstones should be thoroughly evaluated in patients with intractable cholangitis. Regarding portal hypertension, appropriate interventions such as endoscopic variceal treatment and partial splenic embolization are considered to provide good quality of life when hepatic function is preserved.

CONCLUSION

Appropriate therapeutic management is strongly recommended in selected patients with late complications.

Biliary atresia: unity in diversity

Biliary atresia (BA) is a rare disease of unknown origin and unsatisfying outcome. Single, multicenter and national evaluations of epidemiological and outcome data on BA have been periodically published over the course of decades. However, the diversity of the registered parameters and outcome measures impede comparability and cumulative analysis of these very worthwhile studies. Taking into account the fact that BA is a good example of translational research and transition of patients from pediatric surgery and hepatology to transplant surgery and hepatology in general, the interdisciplinary community should make every effort to develop a common platform upon which further activities are conducted. Extending this topic to BA-related diseases might increase the acceptance of research studies and enhance the effectiveness of any recommendations outlined therein. The use of the Internet-based communication platform and registry on http://www.bard-online.com represents the first step in this direction, and the database should be viewed as a helpful tool that guides further activities.

Adjuvant therapy in biliary atresia: hopelessly optimistic or potential for change?

Given that the aetiology of biliary atresia (BA) is complex and that there is a multiplicity of possible pathogenic mechanisms then it is perhaps not surprising that the evidence for effect of a number of different agents is contradictory. Post-operative cholangitis for instance is common, bacterial in origin and various antibiotic regimens have been tested (although none in a randomized trial) but continuation beyond the early post-operative period does not appear to offer any greater protection. There is an inflammatory reaction in about 25-35% of cases of BA illustrated by abnormal expression of class II antigen and upregulation of ICAM, VCAM and E-selectin with an infiltrate of immune-activated T cells (predominantly CD4 + Th1 and Th17) and NK cells and a systemic surge in inflammatory cytokines (e.g. TNF-α, IL-2, IL-12). This has potential as a therapeutic target and is the main hypothesis behind the rationale use of steroids. The first report of steroids was published in 1985 by Karrer and Lilly as "blast" therapy to treat recalcitrant cholangitis, followed by a multiplicity of small-scale uncontrolled studies suggesting benefit. To date there has been one randomized placebo-controlled study with a low-dose (prednisolone 2 mg/kg/day) regimen (2007); one with a high-dose (IV prednisolone 4 mg/kg/day regimen) (2014); two prospective high-dose open-label studies (2013); a prospective comparison of low- and high-dose regimen and a large (380 infants) retrospective comparison. The most recent meta-analysis (2016) identified a significant difference in clearance of jaundice at 6 months (OR 1.59, 95% CI 1.03-2.45, P = 0.04), in patients treated with high-dose steroids, particularly if < 70 days at surgery. Ursodeoxycholic acid (UDCA) may increase choleresis or change the ratio of endogenous bile acids to a less hydrophobic and, therefore, less toxic millieu. UDCA may protect cholangiocyte membranes against damage and perhaps reduce the tendency to fibrogenesis. Biochemical benefit has been shown in a single crossover trial in older BA children who had cleared their jaundice. Other potential adjuvant therapies include immunoglobulin therapy, anti-viral agents and Chinese herbs although real evidence of benefit is lacking.

Epidemiology of Biliary Atresia in Korea

Biliary atresia (BA) is the major cause of cholestasis and the leading indication for liver transplantation (LT). However, the incidence of BA in Korea has not been reported. The aim of this study was to investigate the incidence and clinical outcomes of BA in Korea. We used the Korean universal health insurance database and extracted data regarding BA patients younger than 18 years of age admitted between 2011 and 2015. The incidence of BA was calculated by dividing the number of BA patients by the number of live births. Two hundred forty infants were newly diagnosed with BA. A total of 963 BA patients younger than 18 years of age were followed up for 5 years. The overall incidence of BA was 1.06 cases per 10,000 live births. The incidence of BA was 1.4 times higher for female patients than for male patients. Additionally, significant seasonal variation was observed; in particular, the incidence of BA was 2 times higher from June through August than from December through February. Congenital anomalies were found in 38 of 240 patients (15.8%). Congenital heart diseases were major associated congenital anomalies (6.3%). Several complications developed during the study period, including cholangitis (24.0%), varix (6.2%), and gastrointestinal bleeding (4.4%). Three hundred and one of the 963 BA patients under 18 years of age (31.3%) received LT for BA. The incidence of BA is higher in Korea than that in Western countries. We also report significant gender-associated differences and seasonal variation with respect to the incidence of BA.

[Biliary atresia - signs and symptoms, diagnosis, clinical management]

Biliary atresia is a chronic cholangiopathy leading to progressive fibrosis of both intra- and extrahepatic bile ducts. The cause of the condition is unknown. Fundamental management of biliary atresia is surgical intervention and the outcomes of the treatment depend on the child's age with best results when performed within the first 2 months of life. Thus, the main role of pediatric healthcare is an urgent differential diagnosis and prompt qualification for the surgery, optimal postoperative management and early qualification for the liver transplantation in patients with persistent cholestasis. The authors discuss the clinical presentation, diagnosis and management of biliary atresia.

BILIARY ATRESIA: CURRENT CONCEPTS AND FUTURE PROSPECTS (REVIEW)

Treatment of biliary atresia is a major challenge in pediatric surgery. Early diagnosis and availability of Kasai procedure with its modern modifications improve outcome of biliary atresia treatment. But Kasai procedure does not fully restore anatomical integrity of biliary tract, because Oddi sphincter is not included in reconstructed system. Constant reflux of intestinal content into the biliary tree is a cause of recurrent cholangitis and change in biliary epithelium that, which is a predisposing factor for cholangiocarcinoma. Various methods have been developed to improve Kasai procedure and prevent the reflux (anti-reflux valve, different enteric conduits, etc.). Many authors used biological grafts made from artery, vein, appendix, urether as well as synthetic materials to restore hepaticocholedochus. Although, neither of these methods were implemented in clinical practice. Nowadays, huge attention is paid to organ and tissue bioengineering. Present advances of tissue bioengineering may assist to create bile duct equivalent, which can be used to restore biliary tract in patients with biliary atresia.

Liver disease in the adolescent

This article discusses common liver diseases in the adolescent. Briefly reviewed is the evaluation of the adolescent with new-onset liver enzyme elevation. Then the article discusses common liver diseases, such as nonalcoholic fatty liver disease, hepatitis, metabolic disease, biliary atresia, cystic fibrosis, and inherited disorders of cholestasis. Finally, a management approach to the adolescent with liver disease is outlined, noting the challenges that must be addressed to effectively care for not only liver disease in the adolescent but also the patient as a whole.

A case series of congenital hepatic hilar cyst: recommendations for diagnosis and management

BACKGROUND

Congenital hepatic hilar cysts are rare. Some are simple and do not require intervention, but some biliary cystic malformations impose the risk of morbidity and mortality.

OBJECTIVES

To assess a series of five patients presenting with congenital hepatic hilar cysts.

METHODS

We retrospectively reviewed all cases presenting to our pediatric surgical service between January 2010 and December 2012 and found to have a congenital hepatic hilar cyst. Data regarding clinical, radiological, operative and pathological features were analyzed.

RESULTS

Five children with congenital cyst of the hepatic hilum were identified; four of them were diagnosed prenatally. Four children had undergone surgical intervention: one with intrahepatic choledochal cyst, one with epidermoid cyst, and two with biliary atresia and an associated cyst of the common bile duct. In another case of choledochal cyst the treatment was conservative. All children except one had a good prognosis; one child with biliary atresia required liver transplantation.

CONCLUSIONS

The differential diagnosis of congenital hepatic hilar cyst includes a broad spectrum of pathologies. It is essential to diagnose biliary atresia as early as possible. Signs such as smaller cysts in association with a hypoplastic gallbladder and direct hyperbilirubinemia may be suggestive of biliary atresia.

[A survey on underweight and growth retardation of 51 children before and after liver transplantation]

OBJECTIVE

To evaluate the growth of children in weight and height before and after liver transplantation and the relation between malnutrition and postoperative time.

METHOD

Growth was assessed for children who received liver transplantation from July 2007 to December 2012 after operation during follow-up. Weight and height were measured for 51 children in May 30, 2013. Weight and height percentiles of each child were calculated in accordance with data surveying on physical development of children in nine provinces/municipalities. Underweight was defined as weight less than the third percentile of same age and sex groups. Growth retardation was defined as height less than the third percentile of same age and sex groups. Children were set into 2 groups (before liver transplantation group, after liver transplantation group). The incidence of underweight and growth retardation were analyzed by chi-square test. Children were divided into 4 groups according to the length of time from operation time to May 30, 2013: 1 year after liver transplantation (1-365 days); 2 years after liver transplantation (366-730 days); 3 years after liver transplantation (731-1 095 days) ; 4 years or more after liver transplantation (1 096-2 133 days) . The underweight and growth retardation were analyzed by hierarchical log linear model.

RESULT

The mean age of 51 children was 44.78 months (range 13 months to 13 years old), 26 of them were male and 25 female. The number of children with underweight and growth retardation were 20 (39%) and 35 (69%) respectively before transplantation and were 5 (10%) and 14 (27%) respectively after transplantation. There was a significant difference between underweight incidence before and after operation (χ(2) = 10.385, P = 0.001). There was significant difference between growth retardation incidence before and after operation (χ(2) = 15.710, P = 0.000). The subjects included 10 patients at 1 year after operation (underweight n = 3, growth retardation n = 3), 19 patients at 2 years (underweight n = 1, growth retardation n = 9), 10 patients at 3 years (underweight n = 1, growth retardation n = 2), 12 patients at 4 years and above (underweight n = 0, growth retardation n = 0). Parameter analysis of hierarchical log linear estimates: underweight at 1 year = 0.661, underweight at 2 years = -0.214, underweight at 3 years = 0.119, underweight at 4 years and above = -0.566. Growth retardation at 1 year = 0.282, at 2 years = 0.613, at 3 years = 0.051, at 4 years and above = -0.946.

CONCLUSION

Compared with after liver transplantation, obvious malnutrition existed in patients before transplantation. Patients have the ability to catch-up growth after liver transplantation. Reduced effect of underweight occurred in second year after liver transplantation. Reduced effect of growth retardation occurred in third year after liver transplantation.

[Early diagnosis and comprehensive treatments of post-transplantation lymphoproliferative disorder after pediatric liver transplantation]

OBJECTIVE

To summarize the clinical characteristics, early diagnosis, comprehensive treatment and prognosis of 6 cases of children with post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation.

METHOD

Data of 6 cases with PTLD seen between January 2011 and December 2013 were retrospectively analyzed. The anti-rejection drug dose adjustments, the effect of rituximab, antiviral therapy and comprehensive treatment program after surgery were explored.

RESULT

(1) The diagnosis of PTLD was confirmed by histologic findings. Six cases of PTLD including 3 males and 3 females were diagnosed as congenital biliary atresia and underwent split liver transplantation. The occurrence rate of PTLD was 2.9%. (2) The median time to the development of PTLD was less than 6 months. The initial symptom of PTLD in all patients was fever and clinical manifestations of PTLD were non-specific, depending on the involving organs. Five cases of PTLD developed gastrointestinal symptoms, including diarrhea, abdominal pain, and abdominal distension. One case developed respiratory symptoms, including cough and tachypnea. Three cases had lymph node involvement. In 2 cases pathophysiology involved polymorphic lymphocyte proliferation and in 4 cases B lymphocyte proliferation. (3) Two cases died, in whom EBV DNA was not detected and were diagnosed as PTLD by surgical pathology before death. Four survived cases had high EBV-DNA load and then were diagnosed as PTLD by biopsy pathology. (4) Of the 6 cases of PTLD, 2 cases died and 4 cases survived. The overall mortality was 33%. The dead cases were only treated with laparotomy because of intestinal obstruction or perforation and the survived cases were treated with tacrolimus at reduced doses or discontinuation and rituximab. In 2 cases antiviral therapy (acyclovir) was continued, including 1 cases of intestinal obstruction treated with surgical repair. All the survived patients were followed up for 4 months to 1 year and no evidence has been found.

CONCLUSION

EBV infection is the high risk factor for PTLD after liver transplantation. Close clinical surveillance of EBV DNA for pediatric liver transplantation was important for the early diagnosis of PTLD. Reducing doses of immunosuppressive agents and rituximab is the initial therapy for PTLD. A reduction in the dose of tacrolimus is suggested. Operation therapy can also play a role in the management of local complications.

[Biliary atresia: a condition requiring urgent diagnosis and treatment]

Every neonatal jaundice lasting more than 2 weeks needs urgent investigations, beginning with examination of stools colour, and blood tests with total and conjugated serum bilirubin. If neonatal cholestasis (NC) is confirmed, vitamin K should be immediately injected, and the child should be referred to a specialised centre for investigations and treatment. Biliary atresia (BA) is the first cause of NC. Its diagnosis is urgent, since the chance of success of the conservative surgical treatment (Kasai operation or variants) decreases rapidly as the age at surgery increases. Normal ultrasound scans cannot rule out BA. After prompt work-up looking for the main other causes of NC, BA can often be strongly suspected before surgery, and is confirmed by operative findings and cholangiogram if needed. In case of failure to restore the biliary drainage, biliary cirrhosis progresses and leads to liver transplantation, generally in the first years of life. Currently, more than 90 % of children with BA can live, with a close to normal quality of life for most of them. Early diagnosis and treatment of BA contribute to decrease the needs for liver transplantation in infancy and childhood.

[Postoperative intensive care of biliary atresia patients treated with living donor liver transplantation]

OBJECTIVE

To summarize experience of pediatric intensive care and explore the incidence of complications, the involved pathogens among liver recipients to determine the effective strategies for preventing complications.

METHODS

Between June 2006 and July 2009, 35 children under the age of 14 yr received 35 liver transplantations (LTs) performed at the center. A retrospective review of 22 infants weighing 8.8 kg or less underwent 23 transplants was conducted. Indication for transplantation was biliary atresia. Central venous pressure and arterial blood pressure were monitored continuously and fluid monitoring was performed every 2 hours in the first postoperative week. Blood loss, ascites, and intraoperative transudate loss were primarily replaced with 5% albumin and crystalloids to maintain a central venous pressure between 4 and 6 cm H(2)O. Oral food intake was allowed as soon as possible. To identify vascular or biliary complications, liver doppler ultrasound was performed intraoperatively immediately after reperfusion and after closure of the abdominal wall and postoperatively, twice daily during the first week after surgery. Immunosuppression was initially cyclosporine based, in combination with steroids. Cyclosporine was begun one day prior to transplantation at a dose of 10 mg/(kg·d) divided into two doses, except for cases with hepatic encephalopathy and severe infection. The subsequent doses were adjusted on the basis of recommended trough blood concentrations at different stages. Steroids were eventually discontinued at a time point exceeding 6 months after transplantation. The diagnosis of rejection was confirmed by histology on needle biopsy specimens. Acute graft rejection episodes were treated with a 3-day scheme of IV methylprednisolone 10 mg/(kg·d) followed by recycling doses during the following 3 days (7.5, 5 and 2.5 mg/(kg·d).

RESULTS

The most common postoperative complications were infections (18 cases), gastrointestinal bleeding (3 cases), and vascular complications (4 cases). Rejection occurred in 25% of patients. There was one perioperative death from primary graft non-function. The most common isolated bacteria of the pathogen spectrum were Staphylococcus epidermidis. The median length of stay (LOS) in the PICU for 22 patients (23 transplants) was 10 days (range 5 - 21) and the mean length of stay in the hospital was (18.5 ± 116) days (range, 11 - 48 days). Mean requirement for artificial ventilation was 37.6 h. Mean use of dobutamine, prostaglandin E1 and dopamine was 3.3, 7.5 and 8.8 days, respectively. Preoperatively, 3 children had gastrointestinal bleeding, 18 had ascites, 2 had encephalopathy, 22 had jaundice, and 16 had coagulopathy. There were multiple early operative complications in these infants, including one graft with primary non-function (4.5%). Two patients (9.1%) returned for a total of three times for gastrointestinal bleeding or intra-abdominal hematoma. Three patients (13.6%) had early postoperative intestinal perforations related to adhesions or enterotomy, one was associated with a bowel obstruction. There were 26 episodes of bacterial or fungal infections in 18 (81.8%) patients in the early postoperative period, and infection was the direct/contributing cause of death in one infant. These infections included pneumonia, intra-abdominal abscess or sepsis. All of the bacterial and fungal infections were successfully treated with the appropriate antibacterial and antifungal agents, except for one patient who developed overwhelming sepsis after small bowel perforation. Four (18.2%) patients developed five episodes of acute allograft rejection during the first 15 days after LT. Three of the four patients who developed rejection were transplanted before 2007. All episodes of rejection were treated successfully with intravenous steroid pulse and optimization of cyclosporine levels or FK506 conversion. Of the 20 survivors beyond the perioperative period, two cases (10%) had hypertension requiring therapy.

CONCLUSIONS

Liver transplantation in infants with biliary atresia appears technically demanding but acceptable. There should be essentially no age or size restriction for infants and transplantation can be performed with good outcome, although the frequency of complications is much higher than that seen in older children. The improvement in medical and nursing expertise in this group of very sick infants is based on judicious preoperative donor and recipient selection, meticulous surgical technique (vascular reconstruction and abdominal closure), immediate detection and prompt intervention of complications, and keen postoperative surveillance, which reflect a learning curve for both the technical aspects of liver transplantation and post-operative care of these very small patients in our institution. Liver transplantation for infants can be technically challenging.

Biliary atresia: interdisciplinary initiatives focus on a rare disease

During the last decade, biliary atresia (BA) has attained more interest and the frequency of BA-related publications has increased continuously. Pediatric hepatologists and pediatric surgeons are very active in improving diagnosis and treatment modalities of BA patients, in order to prolong the survival rate of their native liver. Together with transplant surgeons, the bridging of BA patients to liver transplantation (LTx) becomes optimized and as a consequence of this interdisciplinary approach, the overall survival of babies with BA has already reached 90%. Furthermore, basic research into the still unknown origin of BA has advanced, and numerous scientific programs have already linked together. The overriding interest is to discover at least BA's etiology and to turn the treatment of BA patients from a symptomatic to a causative approach. Interdisciplinary and international programs are mandatory and already existing initiatives in Europe, the United States and Japan are going to coordinate their registries, clinical trials and basic research studies for the benefit of the patients and solve the riddle of BA.

Extrahepatic biliary atresia: current concepts and future directions

OBJECTIVE

To provide an updated review on extrahepatic biliary atresia, focusing mainly on its etiopathogenesis, diagnosis, treatment and prognosis.

SOURCES

MEDLINE and PubMed databases were searched using the following keywords: biliary atresia, etiopathogenesis, diagnosis, treatment, prognosis, children.

SUMMARY OF THE FINDINGS

Extrahepatic biliary atresia is the main indication for liver transplantation among pediatric patients. As to its etiology, cytomegalovirus, reovirus and rotavirus have been widely investigated as possible triggers of the immunomediated obstruction of the biliary tree. The immune response, especially the predominant TH1 and interferon-gamma responses, genetic susceptibility and disorders related to the embryonic development of the biliary tree can play a role in the etiopathogenesis of extrahepatic biliary atresia. Yet today, portoenterostomy is the only available treatment, with better results when performed in the first 2 months of life. As to prognosis, all untreated children eventually die due to complications resulting from portal hypertension and liver cirrhosis, and most treated children have to undergo liver transplantation.

CONCLUSIONS

Extrahepatic biliary atresia is still the major indication for pediatric liver transplantation, and to change this scenario some more light should be shed upon the etiopathogenesis of biliary atresia in different disease phenotypes. Future research into the role of interferon-gamma and of other cytokines is necessary in order to assess whether these aspects should be potential targets for therapeutic intervention.

Pathogenesis and treatment opportunities for biliary atresia

Biliary atresia is the single most common cause of chronic cholestasis in children and is the leading indication for liver transplantation worldwide. It results from an inflammatory and fibrosing obstruction of the extrahepatic bile ducts in the first few months of life. Early diagnosis and timely surgical portoenterostomy are necessary for improved biliary drainage, but the liver disease progresses to end-stage biliary cirrhosis in most patients. Although the pathogenesis of disease is largely unknown, recent patient- and animal-based experiments indicate interactions between infectious agents and inflammatory circuits may be important pathogenic mechanisms of disease.

Cholestasis and cholestatic syndromes

PURPOSE OF REVIEW

This review highlights recent advances in understanding the regulation of bile acid transport in cholestasis and the pathogenesis and treatment of a variety of cholestatic conditions.

RECENT FINDINGS

Highlights include new understanding of the role of Mrp4 in bile acid homeostasis in cholestasis, new insights into the pathogenesis of specific cholestatic syndromes including primary biliary cirrhosis, primary sclerosing cholangitis, biliary atresia, and progressive familial intrahepatic cholestasis, and clinical trials of therapies for primary biliary cirrhosis, primary sclerosing cholangitis and intrahepatic cholestasis.

SUMMARY

Our understanding of the molecular mechanisms of cholestasis is advancing. These advances will hopefully lead to more effective therapies for specific cholestatic conditions.

Pediatric hepatobiliary disease

PURPOSE OF REVIEW

This review summarizes recent advancements occurring over the past year in the field of pediatric hepatology. They have helped in the understanding and treatment of several liver and biliary tract disorders of childhood.

RECENT FINDINGS

Recent advancements in the areas of childhood primary sclerosing cholangitis, nonalcoholic fatty liver disease, acute liver failure, liver transplantation, neonatal hemochromatosis, and the Biliary Atresia Research Consortium have been summarized.

SUMMARY

Developments and continued research in these areas have the potential to bring significant benefits to children affected by these disorders.

Biliary atresia due to delayed maturation of the gut hormones' system?--Introducing a new treatment modality

BACKGROUND

Congenital biliary atresia is suspected to originate from prenatal biliary duct inflammation of unknown etiology.

OBJECTIVE

Based on clinical grounds, we aimed to establish a hypothesis on the primary cause of inflammation, and to suggest a causal treatment modality.

CASE REPORT

History. A 28 years old Turkish woman had lost her first child aged two years from congenital biliary atresia (parents second degree cousins). After a miscarriage, in her otherwise uneventful third pregnancy sonography at 34 wks revealed echogenic material in the fetal gallbladder. Nine days later the gallbladder was completely filled with sludge. Chemical inflammation was suspected, and birth was induced at 36+3 weeks in order to allow for surgical flushing of the bile duct. Neonatal clinical chemistry was insuspicious. There was no spontaneous resolution of the sludge within the first 24 hours of life. A trial of medical treatment with intermittent i.v. secretin (0.03 CU/kg/h) and i.v. coeruletid (60 ng/kg/h) was started. Within 24 hours, sludge had resolved.

CONCLUSIONS

We hypothesize that dysmaturation may lead to insufficient induction/production/activity of intrinsic gut hormones resulting in prenatally impaired bile flow, or even inspissated bile. Familial occurrence suggests a genetic defect. Exogenous hormone therapy might be an appropriate treatment modality.

Obstruction of extrahepatic bile ducts by lymphocytes is regulated by IFN-gamma in experimental biliary atresia

The etiology and pathogenesis of bile duct obstruction in children with biliary atresia are largely unknown. We have previously reported that, despite phenotypic heterogeneity, genomic signatures of livers from patients display a proinflammatory phenotype. Here, we address the hypothesis that production of IFN-gamma is a key pathogenic mechanism of disease using a mouse model of rotavirus-induced biliary atresia. We found that rotavirus infection of neonatal mice has a unique tropism to bile duct cells, and it triggers a hepatobiliary inflammation by IFN-gamma-producing CD4(+) and CD8(+) lymphocytes. The inflammation is tissue specific, resulting in progressive jaundice, growth failure, and greater than 90% mortality due to obstruction of extrahepatic bile ducts. In this model, the genetic loss of IFN-gamma did not alter the onset of jaundice, but it remarkably suppressed the tissue-specific targeting of T lymphocytes and completely prevented the inflammatory and fibrosing obstruction of extrahepatic bile ducts. As a consequence, jaundice resolved, and long-term survival improved to greater than 80%. Notably, administration of recombinant IFN-gamma led to recurrence of bile duct obstruction following rotavirus infection of IFN-gamma-deficient mice. Thus, IFN-gamma-driven obstruction of bile ducts is a key pathogenic mechanism of disease and may constitute a therapeutic target to block disease progression in patients with biliary atresia.

Long-term efficacy of partial splenic embolization in children

PURPOSE

To elucidate the role of partial splenic embolization (PSE) procedures, long-term outcome was assessed in terms of the recurrence of thrombocytopenia.

METHODS

A retrospective study was performed after 41 PSE procedures in 36 patients for hypersplenism owing to portal hypertension. The underlying disease was biliary atresia in 32 patients, extrahepatic portal obstruction in 3, and idiopathic cirrhosis in 1.

RESULTS

The average volume embolized was 70.1%. The patients were followed up from 20 days to 182 months (average, 70.8 months). Five patients subsequently died, and 6 underwent liver transplantation. The causes of death or the reasons for liver transplantation were not related to hypersplenism. Eleven patients (30.6%) had recurrence of thrombocytopenia (<100,000/mm3). There was no significant difference in the volume embolized or platelet count before PSE between the patients with and without recurrence of thrombocytopenia. The peak value of platelet count after PSE was significantly lower in the patients with recurrence of thrombocytopenia (P =.0091). In 17 of 24 survivors without liver transplantation, platelet counts remained normal throughout the follow-up period.

CONCLUSIONS

PSE is a safe and effective procedure. Hematologic indices improved in all 36 patients after PSE, and its long-term efficacy was shown in 70% of the survivors.

Biliary atresia

BA is a rare disease of unclear etiology; nevertheless, its impact in the field of pediatric hepatology is significant. It is the most common surgically correctable cause of neonatal cholestasis and is the most common pediatric disease referred for liver transplantation. Little progress has been made with regard to improving outcome or understanding its pathogenesis in the past decade. Fortunately, however, a national, government-sponsored collaborative endeavor has begun that will hopefully make a significant impact upon the progress of designing new treatments for BA and develop a better understanding of its pathogenesis.

Induction of bile ducts in embryonic liver by mesenchyme: a new perspective for the treatment of biliary atresia?

Presently only those forms of Extrahepatic Biliary Atresia (EHBA) with minimal or no intrahepatic manifestations can be treated successfully by extensive hepatoportoenterostomy. Intraoperative macro- and microscopic observations show that the typical pathogenetic manifestations in EHBA are most prominent at the porta hepatis. We therefore postulate that EHBA is the result of a defective embryonic development of the porta hepatis. In rat embryos hepatic bile duct formation is initiated at the porta hepatis and in this context mesenchyme from the periportal region seems to play a major inductive role. In order to demonstrate the role of invading periportal mesenchyme for the process of bile duct rudiment formation we established an organ culture model of the embryonic porta hepatis by recombining periportal mesenchyme with peripheral liver fragments from 15 days old rat embryos (Carnegie Stage 21). The degree of mesenchyme invasion as well as the formation of mesenchyme-surrounded liver cell clusters, rosettes or vesicles (bile duct rudiments) were assessed. Mesenchyme from the porta hepatis invaded the peripheral liver fragments and induced the formation of mesenchyme-surrounded liver cell clusters and rosettes with the beginning of lumen formation. Kidney mesenchyme recombined with liver fragments as a mesenchymal alternative showed almost the same effect, lung mesenchyme showed only a very weak inductive effect. To assess the effect of a diffusible factor versus direct cell contact, a millipore filter with and without paraffin coating was interposed between mesenchyme containing tissue and peripheral liver tissue fragments. Without direct cell contact to mesenchyme no hepatoblast cluster or rosette formation could be observed. Comparing this result to the normal development of the liver in rats our investigations suggest that the embryogenesis of the porta hepatis is probably defined by the following two developmental steps: First, differentiation of the intrahepatic bile duct system which is induced by invading mesenchyme originating from the extrahepatic periportal region and realized by epithelium mesenchyme interaction. Second, fusion of extra- and intrahepatic bile duct systems at the level of the later porta hepatis. Disturbances of this complex process can possibly lead to biliary atresia. Further investigations regarding details of the role of the mesenchyme, its inductive factors and the kidney mesenchyme's inductive potential in liver development may provide a new perspective for future treatment of biliary atresia.

Biliary atresia: an update on our understanding of the disorder

Biliary atresia is the leading cause of cholestasis in infants younger than 3 months. It is also the leading indication for liver transplantation in children. This review focuses on recent advances in the etiology, diagnosis, and management of biliary atresia.

Biliary atresia associated with meconium peritonitis caused by perforation of small bowel atresia

BACKGROUND/PURPOSE

This report describes our experiences with 5 cases of biliary atresia associated with meconium peritonitis caused by perforation of small bowel atresia.

METHODS

A review of medical records was undertaken in an effort to recognize cases of biliary atresia associated with meconium peritonitis.

RESULTS

Five patients of 171 with biliary atresia (2.9%) were detected to have meconium peritonitis caused by perforation of small bowel atresia. The biliary atresia was not suspected during the initial operation for meconium peritonitis. Total parenteral nutrition (TPN) made it difficult to make an early differential diagnosis of biliary atresia because of the presence of TPN-associated cholestatic jaundice, and the Roux-en-Y limb used for hepatic portoenterostomy could not be made long enough to prevent cholangitis caused by preexisting short bowel. The main complications were severe, intractable cholangitis, short bowel syndrome with malnutrition; TPN-associated liver injury; and wound problems. Two patients died of ascending cholangitis, 1 patient of liver failure that was exacerbated by TPN-associated liver injury, and 1 patient is awaiting a liver transplant. Only 1 patient is in good health, being anicteric and showing normal growth and development.

CONCLUSIONS

Biliary atresia is evidently closely associated with meconium peritonitis caused by perforation of small bowel atresia. The management of these patients is more difficult than that of patients with the usual form of biliary atresia, because of the necessity for a long period of TPN and the combined short bowel syndrome. The ideal management of these conditions has yet to be determined.

Nasogastric feeding enhances nutritional status in paediatric liver disease but does not alter circulating levels of IGF-I and IGF binding proteins

OBJECTIVE

Complications of childhood cirrhosis include abnormal growth and malnutrition, associated with abnormalities in circulating IGFs and IGFBPs. Controlled studies suggest that intensive enteral feeding enhances nutritional status. The aim was to ascertain whether nasogastric feeding improves nutritional status in clinical practice and to assess the effect of feeding on serum IGF-I and IGFBPs.

PATIENTS

Thirty-three children (median age 0.6 years) with biliary atresia and failure to thrive who were treated with nasogastric feeding.

MEASUREMENTS

Height, weight and triceps skin fold thickness were measured prior to feeding and regularly for 1 year or until feeding was stopped. Serum IGF-I and IGFBPs were measured by immunoassay at the same intervals.

RESULTS

The median duration of feeding was 3.7 months. Twenty-two stopped feeding after liver transplantation, while 10 stopped electively and 1 boy died. Before feeding, the children were losing weight and height centile. Triceps skin fold thickness, weight and height SD scores improved with feeding. Baseline serum IGF-I and IGFBP-3 were low, while IGFBP-1 and IGFBP-2 were raised. IGF-I and IGFBP-1 did not change with feeding. IGFBP-2 fell and reached a nadir by 3 months, while IGFBP-3 rose temporarily for 4-6 weeks.

CONCLUSIONS

Nasogastric feeding improves body composition in paediatric liver disease but circulating IGF-I and IGFBPs remain abnormal and do not play a major role in mediating these changes. This does not exclude a paracrine or autocrine effect of IGF-I.

Long-term outcome of living related liver transplantation for patients with intrapulmonary shunting and strategy for complications

BACKGROUND

In 320 living related liver transplantation performed between June 1990 and September 1997, there were 21 living related liver transplantation for patients with intrapulmonary shunting, manifested by digital clubbing, cyanosis, and dyspnea. We report the long-term outcome for more 6 months and our strategy to overcome complications in these recipients.

PATIENTS

A total of 21 patients (age range 2-33 years, 19 children and 2 adults, 6 males and 15 females) were classified into three grades according to shunt ratio calculated by TcMAA pulmonary scintigraphy; 5 in mild group (shunt ratio: less than 20%), 6 in moderated group (20%-40%), and 10 in severe group (more than 40%). The original underlying liver disease was biliary atresia in all patients.

RESULTS

Spearmen's correlation coefficient rank test revealed that shunt ratio correlated significantly with PaO2 in room air (P=0.0001), PaO2 in 100% oxygen (P=0.0004), hematocrit (P=0.0276), and period of dyspnea before transplantation (P=0.023).

COMPLICATIONS

Wound infection occurred in 80, 66, and 80%, and bile leakage in 20, 0, 40% in mild, moderate, and severe group, respectively. Patients who had portal vein thrombosis, and intracranial complication were classified as severe group and the incidence was 20 and 20%, respectively. The patient actuarial one year survival was 80, 66.7, and 48%, in mild, moderate, and severe group, respectively, although there was no significant difference. All patients who survived improved hepatopulmonary syndrome and the length of period required for the resolution was significantly correlated to the preoperative shunt ratio (P=0.023).

COMMENTS

Patients with severe shunting are susceptible to wound infection and bile leak. The trend of higher incidence of portal thrombosis and intracranial complications in the severe group was closely related high hematocrit. Secure surgical technique to reduce bile leak and delayed primary wound closure to reduce wound infection were found to be effective. Anticoagulant therapy by infusing heparin through the portal vein followed by coumadin could prevent fatal portal vein thrombosis without counter risk of fatal cerebral hemorrhage.

Biliary atresia: pathogenesis and treatment

Biliary atresia is a disorder of infants in which there is obliteration or discontinuity of the extrahepatic biliary system, resulting in obstruction of bile flow. Untreated, the resulting cholestasis leads to progressive conjugated hyperbilirubinemia, cirrhosis, and hepatic failure. Biliary atresia has an incidence of approximately one in 10,000 live births worldwide. Evidence to date supports a number of pathogenic mechanisms for the development of biliary atresia. An infectious cause, such as by a virus, would seem most pausible in many cases. The clinical observation that biliary atresia is rarely encountered in premature infants would support an agent acting late in gestation. However, no infectious or toxic agent has been conclusively implicated in biliary atresia. Genetic mechanisms likely play important roles, even regarding susceptibility to other specific causes, but no gene whose altered function would result in obstruction or atresia of the biliary tree has been identified. The variety of clinical presentations support the notion that the proposed mechanisms are not mutually exclusive but may play roles individually or in combination in certain patients. Biliary atresia, when untreated, is fatal within 2 years, with a median survival of 8 months. The natural history of biliary atresia has been favorably altered by the Kasai portoenterostomy. Approximately 25 to 35% of patients who undergo a Kasai portoenterostomy will survive more than 10 years without liver transplantation. One third of the patients drain bile but develop complications of cirrhosis and require liver transplantation before age 10. For the remaining one third of patients, bile flow is inadequate following portoenterostomy and the children develop progressive fibrosis and cirrhosis. The portoenterostomy should be done before there is irreversible sclerosis of the intrahepatic bile ducts. Consequently, a prompt evaluation is indicated for any infant older than 14 days with jaundice to determine if conjugated hyperbilirubinemia is present. If infectious, metabolic, endocrine disorders are unlikely and if the child has findings consistent with biliary atresia, then exploratory laparotomy and intraoperative cholangiogram should be done expeditiously by a surgeon who has experience doing the Kasai portoenteostomy. Biliary atresia represents the most common indication for pediatric liver transplantation, representing more than 50% of cases in most series. Transplantation is indicated when symptoms of end stage liver disease occur, including recurrent cholangitis, progressive jaundice, portal hypertension complications, ascites, decreased synthetic function, and growth/nutritional failure.

Treatment of extrahepatic biliary atresia with interferon-alpha in a murine infectious model

The etiology of extrahepatic biliary atresia (EHBA) in newborns remains unknown, although a first infectious animal model with complete obstruction of the common bile duct could be established. Intraperitoneal inoculation of newborn Balb/c mice with rhesus rotavirus induced cholestasis, leading, in most cases, to biliary atresia with lethal outcome, similar to EHBA in human newborns. The influence of interferon-alpha (IFN-alpha) on the hepatotropism of rotavirus infection was investigated in this animal model. Single-dose therapy with 10000 IU of IFN-alpha protected all rhesus rotavirus-infected pups from cholestatic disease. The same dose, injected 5 d after infection, had no protective effect. Starting with onset of cholestatic symptoms, the treatment with 10000 IU of IFN-alpha daily showed good results in 29 mice. Seventy-six percent of the mice recovered after 1 wk of therapy. Histologic investigation revealed normal findings in the hepatobiliary tract of clinically normal mice. Twenty-one percent of the descendants of infected and prophylactic IFN-alpha-treated mice showed cholestatic symptoms after infection with rhesus rotavirus (79% in an untreated control group) and a milder form of the illness. In conclusion, we found that prophylactic treatment with IFN-alpha prevented the hepatobiliary system of newborn Balb/c mice from severe damage by rhesus rotavirus in this artificially designed infectious model for EHBA. Infected and icteric mice, treated for 1 wk with IFN-alpha, had good prospects for recovery and prevention of complete and irreversible occlusion of the extrahepatic bile ducts. Infected and prophylactic IFN-alpha-treated dams gave good protection to their descendants. This means that EHBA in this model could probably be averted by maternal antibodies against rotavirus.

Several mechanisms contribute to the abnormal fatty acid composition of serum phospholipids and cholesterol esters in cholestatic children with extrahepatic biliary atresia

The fatty acid compositions of serum phospholipids and cholesterol esters and direct bilirubinemia were determined in 11 children with cholestasis due to extrahepatic biliary atresia. The levels of the different fatty acids in these lipid classes were compared with those of 22 appropriate controls and correlations with conjugated bilirubinemia were calculated. Significant differences were found in the levels of several fatty acids in these lipid classes, some of which were related to conjugated bilirubinemia. Relationships between fatty acids in phospholipids and cholesterol esters which exist in the control group were either absent or different in the patient group. The results found are compatible with the concept that malabsorption, overflow in blood of phospholipids, which are excreted in bile in healthy individuals, and liver disease per se contribute to the deviating fatty acid compositions. They suggest that administration in the diet may be required of preformed long chain polyunsaturated fatty acids in an easily absorbable form.

Biliary atresia: current management and outcome

Between 1986 and 1994, 42 patients with BA were treated at the Kobe Children's Hospital. These patients underwent a wider excision of the hilar fibrous remnant with Roux-Y reconstruction (with or without intussuscepted valve) without stoma. Corticosteroids were used postoperatively when the stool was acholic or unsteadily cholic. The daily dose was reduced from 20 mg/day by half down. The patients were divided into two groups; in Group I (n = 17, before October 1990), a single course of corticosteroid therapy was employed. In Group II (n = 25, from November 1990 on), this regimen was repeated whenever the stool appeared less cholic. The bile flow improved significantly (excellent in 29% and 60%, and poor in 71% and 32% in Groups I and II, respectively.) Corticosteroids were used in 15 Group I patients with good response in 10 and in 21 Group II patients, 15 of whom had multiple courses. Sixteen of the 21 Group II patients had a good response. The incidence of the cholangitis was not significantly different between the 19 patients with valve and the 23 patients without valve. A 5 year survival significantly improved from 70% in Group I to 96% in Group II. In both groups, the survival rate significantly increased, when compared with the survival rate figured out with an assumption of OLT survivors as dead. On the same assumption, the survival rate of Group II is significantly more than that of the Group II. These suggest a positive contribution of liver transplantation and an aggressive corticosteroid therapy on better survival of Group II.

The treatment of biliary atresia in Europe 1969-1995

European studies of biliary atresia have suggested that the aetiology is heterogeneous. Histological studies of the liver and biliary remnants excised at portoenterostomy have failed to identify any prognostic features except for the size of bile ductules in the porta hepatis. Most of the major series have confirmed that there is a relationship between age at portoenterostomy and clearance of jaundice which has been achieved in more than 67% of infants under 10 weeks of age. Cholangitis reduced survival and bleeding from esophageal varices has occurred in more than 19% of long-term survivors. The 5-year jaundice-free survival rate after portoenterostomy is 37% and the 10 year rate is 18%. It is predicted that these survival rates will improve. Orthotopic transplantation now results in long-term survival in 70% of patients who fail the portoenterostomy operation and long-term survival is now achieved in a majority of children born with biliary atresia.

Resolution of cirrhosis-related pulmonary shunting in two children with a transplanted liver

We treated two children with hypoxemia caused by intrapulmonary shunting associated with cirrhosis secondary to extrahepatic biliary atresia. Following orthotopic liver transplantation, digital clubbing and intrapulmonary shunting were resolved, as demonstrated by normalization of room air arterial blood gases, reduction in shunt fraction, and perfusion lung scanning with 99mTc-labeled macroaggregates of albumin. We recommend that early liver transplantation be considered for young subjects with a severe hepatopulmonary syndrome.