Hyaline cartilage at the portal plate and gallbladder in biliary atresia.

Histologic features of the portal plate in extrahepatic biliary atresia and their impact on prognosis—a Danish study

Background: The presence of cartilage in extra hepatic biliary tree is an unusual finding. An isolated presence of the cartilage is possibly heterotopic or occurs as a metaplastic response to the inflammatory insult.Material and methods: We had examined the liver biopsy and the resected specimen of a biliary atresia (BA) after Kasai procedure.Results: There was hyaline cartilage around the common hepatic and common bile duct in a 3-months-old male infant with distal obstructive cholangiopathy on liver biopsy and had positive serum IgM for cytomegalovirus (CMV). Similar findings could not be documented in the pericholedochal tissue of any of the 25 other pediatric cases operated for BA or choledochal cyst and three neonatal autopsies performed for liver-related deaths.Conclusion: Peri-bile duct cartilage is a unique finding and could represent an unusual form of heterotopia or connective tissue metaplasia.

Histologic oddities at the porta hepatis in biliary atresia

Biliary atresia.

Neonatal cholestatic disorders are a group of hepatobiliary diseases occurring within the first 3 months of life. Bile flow is impaired, and patients have conjugated hyperbilirubinemia, acholic stools, and hepatomegaly. Overall, 1 in 2,500 live births is affected with a neonatal cholestatic disorder (1). The two most common causes of neonatal cholestasis are biliary atresia and idiopathic neonatal hepatitis, accounting for up to 50% to 70% of cases. Other causes include a variety of neonatal infections (viral, toxoplasmosis, syphilis, bacterial), metabolic and genetic diseases, progressive familial intrahepatic cholestatic disorders (PFIC), paucity of interlobular bile duct disorders (e.g., Alagille syndrome), choledochal cyst, ischemia–reperfusion injury, association with parenteral nutrition administration, and other conditions (Table 1). Despite clinical improvement after the portoenterostomy procedure, approximately 70% to 80% of children with biliary atresia will eventually require liver transplantation; thus, biliary atresia alone accounts for almost 50% of all liver transplants performed in children (1). It should be noted that $77 million is spent each year in the United States on liver transplantation for children and the ensuing hospitalizations (2). This sum of money covers 0.2% of total health care expenditures related to children, even though these children represent 0.0006% of the total pediatric population. Importantly, this disproportionate expenditure for liver transplantation in children could be cut in half if improved therapies for biliary atresia were developed that could abrogate or further delay the need for liver transplantation. Remarkably, little is known about the etiopathogenesis of biliary atresia; consequently, there has been slow progress in developing improved therapies or preventative strategies during the past decade. The purpose of this review is to summarize recent advances in the diagnosis and management of biliary atresia, examine the clinical outcome, describe the evolving theories of the etiology and pathogenesis of this disorder, and highlight gaps in our current knowledge.

Hepatic fibrosis scores and serum biomarkers in pediatric hepatology.

Postnatal development of the mouse palate

Variability of diagnostic approach, surgical technique, and medical management for children with biliary atresia in Canada — Is it time for standardization?

Biliary atresia, defined as the complete or partial absence of the extrahepatic biliary system, has an incidence of approximately 1 in 10,000 live births worldwide. Untreated, this disorder produces biliary obstruction and eventual hepatic failure, although the Kasai portoenterostomy and, more recently, orthotopic liver transplantation have significantly improved survival rates (1). Despite more than 150 years of clinical experience with biliary atresia, the pathogenesis of this disorder remains elusive. Numerous etiologies have been proposed, including perinatal or neonatal infection (2,3), ischemic insults (4), and abnormal bile acid metabolism (5). Additionally, there is a subset of patients with biliary atresia who have other congenital defects, including polysplenia, cardiac defects, abdominal vascular abnormalities, and malrotation, suggesting a defect in the development of embryonic laterality (6). The pathogenesis of biliary atresia appears multifactorial, including improper development of and inflammatory damage to the biliary tree. In this report we describe a case of biliary atresia associated with a fatty acid oxidation defect. While this association has not previously been reported, occasionally fatty acid oxidation defects are associated with liver disease and pathologic changes in the liver. Typically, these disorders present in infancy, and if undetected, may result in episodic vomiting, hypoketotic hypoglycemic coma, sudden infant death syndrome, and a Reye-like syndrome with acute fatty liver and cerebral edema (7). One of the defects in fatty acid oxidation, long chain 3-hydroxyl-CoA dehydrogenase (LCHAD1) deficiency, contains unusual features in addition to those described above, including muscle weakness, left-ventricular hypertrophy, peripheral neuropathy, pigmentary retinopathy, and fibrotic or cirrhotic liver (8,9). LCHAD enzyme activity is conferred by the trifunctional protein, a hetero-octomeric multimer containing 4 α and 4 β subunits that also is responsible for 3-ketoacyl-CoA thiolase and enoyl-CoA hydratase enzyme activities (10). Although the clinical presentations appear indistinguishable, the biochemical spectrum of trifunctional protein deficiency may be divided into isolated LCHAD deficiency and global loss of all three enzyme activities. The latter has been reported less frequently, and interestingly, all cases with documented β subunit mutations demonstrate loss of all three enzyme activities (11,12). The following represents a case of a β subunit mutation of trifunctional protein in which the patient also exhibits biliary atresia. CASE REPORT The patient was the full-term product of a pregnancy complicated only by mild hypertension. Family history was notable for a previous miscarriage and a previous healthy child; there were no major illnesses in the family and the parents were unrelated and of Italian origin. The patient attracted medical attention in the first week of life when he was noted to have hepatomegaly and a conjugated hyperbilirubinemia. Chemistry studies were notable for a total bilirubin of 11.6 mg/dl with 6.9 mg/dl conjugated, alanine aminotransferase (ALT) of 57 IU/L, aspartate aminotransferase (AST) of 99 IU/L, and γ-glutamyl transferase (GGT) of 538 IU/L. Notable results from his workup for neonatal hepatitis included: negative serologies to Hepatitis B and Hepatitis C viruses and to toxoplasmosis; cytomegalovirus serologies consistent with past infection likely from maternal antibodies; normal α1-antitrypsin phenotype; normal urine organic acids and normal serum amino acids, and a DISIDA scan demonstrating no excretion into the small bowel within 24 hours. A percutaneous liver biopsy produced pathology consistent with biliary atresia or obstruction. Figure 1 displays the results of this biopsy, demonstrating bile ductular proliferation, focal bile plugs, and mild portal fibrosis and periportal cholestasis; these results are consistent with biliary atresia. For comparison, Figure 2 shows a biopsy specimen from an unrelated patient with LCHAD deficiency, demonstrating the steatosis and fibrosis others previously reported in this condition (13).FIG. 1.: Patient's first biopsy, at 24 days of age, reveals portal expansion and fibrosis with extensive bile duct and ductular proliferation consistent with obstruction due to extrahepatic biliary atresia (H&E, ×200).FIG. 2.: Liver biopsy from a 19-month-old white female with demonstrated long-chain fatty acid COA deficiency is characterized by periportal fibrosis and bridging with thin fibrous septa, no significant bile duct proliferation, and generalized hepatocellular swelling with minimal vacuolization (H&E, ×200).A Kasai portoenterostomy was performed in the third week of life, which was tolerated well by the patient. Figure 3 depicts the extrahepatic biliary tree, removed at the time of the portoenterostomy, with diminutive ducts and concentric fibrosis, confirming the diagnosis of biliary atresia. At 8 weeks of age, he was noted to be anicteric but failing to thrive, and was thus started on nasogastric tube feedings of Pregestimil and breast milk, which led to good weight gain.FIG. 3.: A Kasai portoenterostomy performed a few days after the liver biopsy of Figure 1 yielded a diminutive extrahepatic biliary system without an observable lumen. The section from the common bile duct reveals occlusion by concentric fibrosis, inflammation, and hemorrhage (H&E, ×40).At six months of age, he developed symptoms of pain thought to be due to an inguinal hernia. Bilateral herniorrhaphies were performed, and the patient was discharged home. He became increasingly weak and fussy, and was refusing feeds. On readmission, he was noted to have ascites and splenomegaly, and an abdominal ultrasound demonstrated dilated areas in the biliary system. A revision of his Kasai was performed but was unsuccessful in re-establishing adequate biliary drainage. Postoperatively, he suffered seizures and a respiratory arrest requiring an unexpectedly long recovery course while intubated and mechanically ventilated. The recovery was complicated by prolonged neuromuscular weakness, and he was noted to have left-ventricular hypertrophy by echocardiogram. A full neurologic and metabolic evaluation included an acylcarnitine profile demonstrating elevated 3-hydroxy long-chain species, results consistent with long-chain 3-hydroxyl-CoA dehydrogenase deficiency. At 9 months of age, the patient underwent orthotopic liver transplantation as treatment for the end-stage cholestatic liver disease associated with his biliary atresia. A second transplantation was required on postoperative day 2 due to primary nonfunction of the graft. After a lengthy hospitalization due to complications of his metabolic disease, he was discharged home with normal liver function. Of note, he continues to exhibit signs of LCHAD deficiency, experiencing typical crises characterized by muscle weakness, blood sugar instability, elevated creatine kinase levels, and even cardiac arrhythmias when stressed with intercurrent infections. This suggests that the liver transplantation has not been curative for this metabolic disorder, a finding that will be discussed in greater detail in a separate report (G. T. Berry, manuscript in preparation). The patient's younger brother was also found to be a compound heterozygote for the trifunctional protein β subunit mutation, diagnosed in utero. The younger brother, who did not develop biliary atresia and has been maintained on a restricted diet with close metabolic monitoring and support, has no evidence of chronic liver disease up to the present time, at the age of 2 1/2 years. Biochemical analysis of the LCHAD deficiency in our patient demonstrated that he in fact belongs to the smaller subset of patients in which there is a global defect in all three enzyme activities of the trifunctional protein. Analysis of his genes for both the α and β subunits of trifunctional protein showed that he is a compound heterozygote for a mutation in the β subunit of trifunctional protein, with mutations of arginine 84 glycine (exon 6) and an arginine 38 cystine (exon 4) (G. T. Berry, manuscript in preparation). DISCUSSION We have presented a case of biliary atresia associated with trifunctional protein deficiency. The findings of the liver biopsy, as displayed in Figures 1 and 3, are entirely consistent with biliary atresia, encompassing all of the pathologic findings well known in this disease. The patient also has trifunctional protein deficiency, exhibiting symptoms such as decompensation during stress, weakness, and left-ventricular hypertrophy. His acylcarnitine profile showed increased long-chain fatty acid metabolites, and biochemical and genetic studies demonstrated decreased activity of trifunctional protein with compound heterozygous mutations in the β subunit of that gene. The mutations exhibited in our patient are distinct from those described previously in the β subunit (11). The overwhelming majority of reported patients with LCHAD deficiency have point mutations in the α subunit of the trifunctional protein, resulting in isolated deficiency of LCHAD enzyme activity (14–16). To date, there have been 8 reported cases of global trifunctional protein deficiency, and these cases demonstrate clinical features indistinguishable from those of isolated LCHAD deficiency (11,12,17–21). The patients with mutations in the β subunit have global trifunctional protein deficiency (11,12), as do patients with α subunit mutations such as splice site mutations that are predicted to prevent protein expression (20). Global trifunctional protein deficiency and isolated LCHAD deficiency both present with hepatomegaly, among other signs, and several cases have progressed to hepatic insufficiency or frank hepatic failure (7–9). The pathology from these patients consistently demonstrates steatosis, and occasionally fibrosis and cirrhosis as well, although none has been reported to have biliary atresia. Our patient could represent an endpoint on the spectrum of steatosis and hepatic dysfunction, or may have developed biliary atresia as a consequence of the fatty acid oxidation defect, or in fact could have developed biliary atresia independently of the metabolic defect. In those patients with LCHAD deficiency reported to demonstrate hepatic fibrosis, there is no clear etiology for these findings. A likely explanation may be that the steatosis results in hepatocyte death and eventual replacement by fibrous tissue. Perhaps in our patient the resulting inflammation also affected the biliary system, resulting in fibrosis and atresia of the intrahepatic and extrahepatic bile ducts. We did not, however, see any signs of steatosis or inflammation similar to that seen in Figure 2 in any biopsy specimen, making such an explanation unlikely, although the patient was not biopsied during a period of metabolic crisis. A more plausible connection would have to invoke a cause that could lead to fibrosis and biliary atresia without also resulting in steatosis. There does appear to be some element of LCHAD deficiency or trifunctional protein deficiency that is toxic to the liver. Accumulation of upstream metabolites may cause accumulation of fat secondary to an inability of the liver to metabolize the products upstream of LCHAD. Interestingly, our patient did not exhibit the steatosis frequently seen in LCHAD deficiency. While this may be due to the clinical heterogeneity of this disorder, perhaps these potentially toxic metabolites were excreted into the biliary system, resulting in inflammatory damage to the bile ducts significant enough to cause atresia. Such a mechanism would have to occur in utero, suggesting that any toxic metabolites would not be cleared by the fetus. Others have proposed that toxic bile intermediates may lead to biliary atresia (5), and one could speculate that the upstream metabolites produced in the absence of LCHAD may be directly excreted into bile or converted into toxic derivatives of bile components. There is, however, little evidence either in our patient or in the literature to support such an assertion. Certainly the findings observed in our patient could be the chance association of two rare events. In that case, the lack of any findings on biopsy in this patient consistent with LCHAD deficiency suggests that biliary atresia may in fact be protective against the steatosis and fibrosis seen in LCHAD deficiency, although our biopsies were not in fact obtained during periods of metabolic crisis. The overwhelming majority of reported patients with LCHAD deficiency have some degree of hepatopathy (9,15,16), and if our patient had none from the metabolic disorder and exclusively suffered damage from biliary atresia, a causal link may be postulated. Perhaps the backup of bilirubin would prevent the accumulation of fatty acid intermediates in the hepatocyte, or the underlying cause of our patient's biliary atresia—infectious, genetic, vascular, or alternative—prevented the buildup. Alternatively, our patient may have a phenotype of trifunctional protein deficiency that would not have included liver disease, and his development of biliary atresia arose by chance. Of note, our patient was relatively young at the initial presentation of biliary atresia and at the time of his Kasai portoenterostomy. His underlying LCHAD deficiency may have in fact resulted in his earlier presentation, perhaps because of subclinical hepatocellular compromise that accelerated the disease process of biliary atresia. The connection between trifunctional protein deficiency and biliary atresia that we have presented is by its very nature tenuous, largely because the mechanisms by which either of these entities become disease are not well understood. Until there is a greater understanding of these disease processes, we must assume that in our one patient, the two entities arose by chance. The possibility of a mechanistic connection, including one not proposed here, is of course intriguing. Regardless of any possible association, clinicians with patients diagnosed with LCHAD or other metabolic derangements should be vigilant for the possible diagnosis of biliary atresia as well, especially given the narrow window for treatment opportunity in biliary atresia. Furthermore, our case demonstrates that even in those patients in whom the initial liver biopsy is classic for biliary atresia, deviations from the expected clinical course may suggest alternative or additional diagnoses that should be evaluated.

Introduction. Biliary atresia (BA) is an idiopathic, progressive obliterative cholangiopathy of unknown etiology. The incidence of BA is 5?10 cases per 100,000 live births. Two clinical phenotypes of BA have been described: syndromic and non-syndromic form. From 1959, Kasai procedure is a standard therapeutic procedure. However, patients in whom there is an association of BA with other structural anomalies may have a worse outcome after the procedure. The goal was to present our patient with unusual form of BA associated with intestinal malrotation. Case report. We present a two-month-old female infant hospitalized because BA was suspected. On the echosonographic examination of the abdomen the gallbladder was not visible. Intraoperative diagnosis of BA was confirmed, and the Kasai procedure was performed. During the operation, intestinal malrotation with Ladd?s bands was identified. In this case, after the complete Ladd procedure, we decided to trace the Roux coil through the mesoduodenum and then behind the duodenum towards the portal plate, where a portoenterostomy was then created in a standard way. During the ?follow-up? the infant was free of complaints, the stools were normally discolored, and the values of liver function tests had a downward trend. Conclusion. Any doubt about the diagnosis of BA obliges us to determine the existence of all other possible anatomical abnormalities and associated anomalies, due to their potential importance in changing treatment plans and surgical approach, but also the impact on the outcome of treatment.

Increased CXCR3 expression associated with CD3-positive lymphocytes in the liver and biliary remnant in biliary atresia

Delayed Postnatal Presentation of Biliary Atresia in 2 Premature Neonates

The key characteristic of biliary atresia (BA) is obliteration of the extrahepatic bile ducts at the level of the porta hepatis. We aimed to relate the immunohistochemical features of remnant biliary ductules at the porta hepatis with clinical features and outcomes. Samples were immunostained with anti-cytokeratin 20 (CK20), vimentin and alpha-smooth muscle actin (aSMA). Primary outcome was set as clearance of jaundice (bilirubin ≤ 20μmol/L) following Kasai portoenterostomy (KPE). Eighty-two cases were classified into syndromic BA (n = 10), cystic BA (n = 7), CMV IgM+ BA (n = 9) and isolated BA (n = 56). CK20 expression was confirmed in 40/82 (49%), and vimentin expression in 19/82 (23%). aSMA was negative in all cases studied. CK20 expression was less common in isolated BA (n = 20/56, 36%) compared to CMV IgM+ BA (n = 8/9, 89%), cystic BA (n = 7/7, 100%) (isolated BA vs non-isolated BA, P = 0.0008). There was no difference in vimentin expression among the sub-groups (isolated BA vs. non-isolated BA; P = 0.39). CoJ was achieved in 52/82 (63%) overall with significant difference depending simply on sub-group [e.g. syndromic BA 9/10 (90%)]. CK20 expression was associated with a diminished rate of CoJ in the entire cohort [CK20+ 32/56 (57%) vs. CK20- 20/26 (77%); P = 0.04]. By contrast no correlation was observed between vimentin expression and CoJ (P = 0.13). CK20+ expression was associated with reduced clearance of jaundice in BA and a trend towards reduced native liver survival.

Biliary atresia liver histopathological determinants of early post-Kasai outcome

Biliary atresia (BA) is an obliterative cholangiopathy presenting in the newborn period that leads to biliary cirrhosis and the need for liver transplantation in infancy unless treated early with a palliative Kasai portoenterostomy. BA is the most frequent indication for liver transplantation in children, but the pathogenesis remains unknown (1). Abnormalities of primary cilia are the cause of syndromes such as autosomal recessive polycystic kidney disease, in which renal cyst formation is associated with liver disease (2). The liver disease in ciliopathies is a ductal plate malformation leading either to congenital hepatic fibrosis or hepatic cyst development (3). In 10% to 20% of cases with BA (syndromic BA), there is an association with other specific developmental defects, including a laterality abnormality (situs inversus). Laterality is determined by primary cilia, and genes affecting laterality are involved in the organisation of cilial microtubules within the embryonal central node (4). In the present study we investigated children with BA who developed renal cysts to increase our understanding of the pathological process. We evaluated the effect of liver transplantation on cyst formation, assessed the role of primary cilia using fibrocystin as a cilial marker and looked for PKHD1 mutations in this group, and finally determined the function of their motile respiratory cilia.