Analysis of the pathomorphology of the intra- and extrahepatic biliary system in biliary atresia

Growth Factors Assessed during Kasai Procedure in Liver and Serum Are Not Predictive for the Postoperative Liver Deterioration in Infants with Biliary Atresia

Background: Biliary atresia (BA) is a neonatal cholangiopathy characterized by progressive destruction of the biliary system resulting in liver cirrhosis. Residual bile drainage can temporarily be achieved through Kasai portoenterostomy (KPE) and some children show long-term survival with their native liver. However, most children eventually require liver transplantation (LTX). As several growth factors (GF) and chemokines have been shown to promote fibrogenesis in the liver, we assessed whether GF are predictive for the course of disease. Material and Methods: Liver and sera samples were collected from 49 infants with BA during KPE. Levels of 13 different GF were measured by multiplex immunoassay. Patient outcomes were stratified into favorable (bilirubin < 20 µmol/L at 2-year follow-up) and unfavorable (LTX). GF levels were compared between groups by a t-test, correlation coefficients were calculated, and principal component analyses performed. Results: Twenty-two patients showed a favorable and 27 an unfavorable disease course. No relation of GF and outcome could be established. In both groups, high levels of SDF-1alpha/CXCL12 (1473.0 ± 497.5 pg/mL), FGF2 (301.2 ± 207.8 pg/mL), and VEGF-a (209.0 ± 146.4 pg/mL) levels were measured within the liver, followed (in descending order) by PDGF-bb, LIF, GM-CSF, BDNF, VEGF-d, beta-NGF, IL-7, SCF, PIGF-1, and EGF. Serum marker levels showed much higher mean variation compared to hepatic values and no correlation to the protein microenvironment in the liver. Conclusions: Our study demonstrates high amounts of GF in livers from infants with BA at KPE, but no correlation to the outcome or serum values could be established. Our data suggest that local or systemic GF levels are unsuitable for prediction of the disease course. Collectively, we conclude that in BA the degree of proliferative activity caused by GF is a dismissible factor for the further course of disease.

Inflammation, Active Fibroplasia, and End-stage Fibrosis in 172 Biliary Atresia Remnants Correlate Poorly With Age at Kasai Portoenterostomy, Visceral Heterotaxy, and Outcome

Published histologic studies of the hilar plate or entire biliary remnant at the time of Kasai portoenterostomy (KHPE) have not provided deep insight into the pathogenesis of biliary atresia, relation to age at surgery, prognosis or the basis for successful drainage. We report detailed histologic findings in 172 centrally reviewed biliary remnants with an average of 6 sections per subject. Active lesions were classified as either necroinflammatory (rare/clustered in a few subjects) or active concentric fibroplasia with or without inflammation (common). Inactive lesions showed bland replacement by collagen and fibrous cords with little or no inflammation. Heterogeneity was common within a given remnant; however, relatively homogenous histologic patterns, defined as 3 or more inactive or active levels in the hepatic ducts levels, characterized most remnants. Homogeneity did not correlate with age at KHPE, presence/absence of congenital anomalies at laparotomy indicative of heterotaxy and outcome. Remnants from youngest subjects were more likely than older subjects to be homogenously inactive suggesting significantly earlier onset in the youngest subset. Conversely remnants from the oldest subjects were often homogenously active suggesting later onset or slower progression. More data are needed in remnants from subjects <30 days old at KHPE and in those with visceral anomalies. Prevalence of partially preserved epithelium in active fibroplastic biliary atresia lesions at all ages suggests that epithelial regression or injury may not be a primary event or that reepithelialization is already underway at the time of KHPE. We hypothesize that outcome after KHPE results from competition between active fibroplasia and reepithelialization of retained, collapsed but not obliterated lumens. The driver of active fibroplasia is unknown.

Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia.

The correlation between plasma cytokine levels in jaundice-free children with biliary atresia

BACKGROUND

T helper (Th) cell cytokines modulate inflammation and play a role in biliary atresia (BA). The aim of the study is a cross-sectional assessment of the levels of Th cytokines in the jaundice-free post Kasai procedure patients.

METHODS

There were 40 jaundice-free patients with BA and 28 normal controls enrolled. Patients were divided into 3 groups, including normal liver function, impaired liver function, and portal hypertension. Plasma concentration of Th1 [interferon-γ (INF-γ), interleukin (IL)-2], Th2 (IL-4, IL-10), Th3 [transforming growth factor-β1 (TGF-β1)], Th17 (IL-17) cytokines, and stromal cell-derived factor-1α (SDF-1α) were investigated.

RESULTS

The IFN-γ level was significantly higher in the BA patients with impaired liver function and portal hypertension than controls (P<0.0001 and P<0.0001, respectively). There was a significantly increase of TGF-ß1 in all BA groups compared with controls (P=0.003). The reduction of SDF-1α expression was found in BA groups (P<0.0001). IL-10 levels significantly correlated with aspartate aminotransferase to platelet ratio index (r=0.496, P=0.001). For the cytokine correlations, there were no correlations of Th1, Th2 and Th17 cytokine with the other measured cytokines, but TGF-ß1 was negatively correlated with SDF-1α levels (r=-0.327, P=0.039).

CONCLUSIONS

IFN-γ and IL-10 are likely to be involved in the disease progression in BA. Besides, TGF-β1 is found to be a suppression marker associated with SDF-1α levels and reduced production of TGF-β1 may be associated with the disease progression.

Transient elastography and sonography for prediction of liver fibrosis in infants with biliary atresia

OBJECTIVES

The purpose of this study was to assess the diagnostic performance of transient elastography and sonography for noninvasive evaluation of liver fibrosis in infants with biliary atresia.

METHODS

Forty-seven infants with biliary atresia who underwent both transient elastography and sonography before surgery were included in this study. Two types of transient elastographic probes were used: an M probe, which is used for the general adult population; and an S probe, which is specific to children. Transient elastographic measurements and sonographic findings such as triangular cord thickness and hepatic artery and portal vein diameters were compared with the METAVIR histopathologic fibrosis scoring system.

RESULTS

Only transient elastography (ρ = 0.63; P < .001) was significantly correlated with METAVIR fibrosis stages. The areas under the receiver operating characteristic curves for transient elastography were 0.86 and 0.96 for diagnosis of severe fibrosis and cirrhosis, respectively. The cutoff value of transient elastography for diagnosis of severe fibrosis was greater than 9.6 kPa, with sensitivity of 89.5% and specificity of 75%. The cutoff value of transient elastography for diagnosis of cirrhosis was greater than 18.1 kPa, with sensitivity of 100% and specificity of 90.5%. The success rate for the S probe (100%) was significantly higher than that for the M probe (77%; P < .001).

CONCLUSIONS

Transient elastography may be a useful noninvasive method for diagnosis of severe fibrosis and cirrhosis and may help predict outcomes before surgery or invasive liver biopsy in infants with biliary atresia. The success rate of transient elastography in infants was improved by using the S probe.

Biliary atresia: a multidisciplinary approach to diagnosis and management

CONTEXT

Biliary atresia is an inflammatory cholangiopathy of infancy that results in progressive fibrosis and obliteration of bile ducts and represents the main indication for liver transplant in young children. In spite of extensive investigation, its etiology has remained poorly understood. Timely surgical intervention (Kasai procedure) may result in significant benefit to these patients and represents the final goal of an accurate diagnostic evaluation.

OBJECTIVE

To present an overview of biliary atresia, including clinical and surgical approaches to this disease, with emphasis on the histopathologic evaluation.

DATA SOURCES

Review of relevant literature indexed in PubMed (US National Library of Medicine).

CONCLUSION

A well-coordinated multidisciplinary approach is required in the assessment of suspected cases of biliary atresia. Pathologic examination of biopsy specimens is an integral part of the diagnostic algorithm and, therefore, plays a pivotal role in the diagnostic evaluation of this disease.

Diagnostic utility of CD10 in benign and malignant extrahepatic bile duct lesions

CD10, a cell surface enzyme with neutral metalloendopeptidase activity, is a marker for intestinal epithelial brush border. It is also present in normal bile ducts and gallbladder epithelia but is absent in cholangiocarcinomas. However, the expression profile of CD10 in benign and malignant extrahepatic biliary lesions has not been studied. In this study, 69 biopsies, 9 resections, and 9 cell blocks prepared from fine-needle aspirations of the extrahepatic bile ducts from 86 patients were studied immunohistochemically for CD10 expression. The majority of cases contained normal biliary epithelium (NL, n=64), along with foci of benign or malignant lesions in various combinations. Benign lesions included reactive atypia (n=35), low-grade dysplasia of unknown significance (n=21), and bile duct adenoma (BDA, n=1). Malignant lesions included high-grade dysplasia (HGD, n=45) and invasive adenocarcinoma (IC, n=30). As expected, the NL showed strong continuous staining at the apical surface in all cases. Benign lesions were also CD10 positive in all but 3 cases; however, the staining pattern was discontinuous, with positive cells varying from 20% to 80%. None of the malignant lesions showed CD10 immunoreactivity, except for 2 HGD cases and 1 IC case, which exhibited focal staining. The Pearson χ2 and Fisher exact tests showed significant statistical difference in CD10 expression among the study groups (P<0.001). Our findings suggest that absence of CD10 expression in strips of atypical biliary epithelial cells may be a phenotype associated with malignant transformation and may serve as a useful marker to aid in the evaluation of bile duct biopsies, in which distinction between benign and malignant lesions on biopsies or cytology specimens can be extremely challenging because of limited sampling, crush artifact, and frequent inflammatory/reactive changes.

Liver and portal histopathological correlation with age and survival in extra hepatic biliary atresia

AIM

To grade histopathological parameters in biliary atresia (BA) and correlate it with advancing age and outcome.

METHOD

Liver and porta hepatis biopsies of 18 BA cases were graded for cholestasis (C), hepatocellular degeneration (HD), bile duct proliferation (BDP), bile duct fibrosis (BDF), bile duct inflammation (BDI), portal edema (PE), portal inflammation (PI) and portal fibrosis (PF) with a total histopathological score (THS) of 25. Confidence intervals were calculated. Image analysis at porta hepatis for largest subhepatic bile ductule diameter (BDD) and area was correlated with liver histopathology. Patients were followed up to at least 1 year after surgery. Four cases of neonatal autopsies were taken as control.

RESULTS

Mean age at Kasai was 95.5 + 32.03 (51-172) days. Mean THS was 16.83 + 2.57 (13-23) with no significant difference in relation to age <90; >90 days (p = 0.4410) or age <60; 61-90; 91-120; >121 days (p = 0.6549). There was no significant difference with relation to age in grading of parameters; C (p = 1.000) HD (p = 0.638), BDP (p = 0.530), BDF (p = 0.342), BDI (p = 0.395), PE (p = 0.476), PI (p = 0.342), PF (p = 0.530), BDD (p = 0.1097) and area (p = 0.1097). There was no significant difference between survival and age at operation (p = 0.4178) or THS (p = 0.3025).

CONCLUSION

Advanced histopathological findings even at younger age suggests the need to consider BA as an emergency.

Hedgehog activity, epithelial-mesenchymal transitions, and biliary dysmorphogenesis in biliary atresia

Biliary atresia (BA) is notable for marked ductular reaction and rapid development of fibrosis. Activation of the Hedgehog (Hh) pathway promotes the expansion of populations of immature epithelial cells that coexpress mesenchymal markers and may be profibrogenic. We examined the hypothesis that in BA excessive Hh activation impedes ductular morphogenesis and enhances fibrogenesis by promoting accumulation of immature ductular cells with a mesenchymal phenotype. Livers and remnant extrahepatic ducts from BA patients were evaluated by quantitative reverse-transcription polymerase chain reaction (QRT-PCR) and immunostaining for Hh ligands, target genes, and markers of mesenchymal cells or ductular progenitors. Findings were compared to children with genetic cholestatic disease, age-matched deceased donor controls, and adult controls. Ductular cells isolated from adult rats with and without bile duct ligation were incubated with Hh ligand-enriched medium ± Hh-neutralizing antibody to determine direct effects of Hh ligands on epithelial to mesenchymal transition (EMT) marker expression. Livers from pediatric controls showed greater innate Hh activation than adult controls. In children with BA, both intra- and extrahepatic ductular cells demonstrated striking up-regulation of Hh ligand production and increased expression of Hh target genes. Excessive accumulation of Hh-producing cells and Hh-responsive cells also occurred in other infantile cholestatic diseases. Further analysis of the BA samples demonstrated that immature ductular cells with a mesenchymal phenotype were Hh-responsive. Treating immature ductular cells with Hh ligand-enriched medium induced mesenchymal genes; neutralizing Hh ligands inhibited this.

CONCLUSION

BA is characterized by excessive Hh pathway activity, which stimulates biliary EMT and may contribute to biliary dysmorphogenesis. Other cholestatic diseases show similar activation, suggesting that this is a common response to cholestatic injury in infancy.

Impact of dieldrin on liver morphological and biochemical parameters of rats

The current study deals with the effect of the organochlorine insecticide on the liver of Wistar rats. The dieldrin effect on rats was tested after a single intraperitoneal (i.p.) injection of two doses: 3 and 6 mg/kg and observations were made 4 days later. Animals showed a significant dose-dependent increase in relative liver weight. Elevations of transaminases (aspartate aminotransferase [AST], alanine aminotransferase [ALT]), bilirubin and total activity of lactate dehydrogenase (LDH) were recorded in the sera of treated rats. Serum LDH-5 isoenzyme activity increases in a dose-dependent manner. In contrast, LDH-1 activity does not show any significant variations with respect to controls. Histological examination of the liver of dieldrin-treated animals revealed cytoplasmic vacuolation, focal necrosis and nuclear enlargement of hepatocytes. This study suggests that biochemical assessment (transaminases, LDH and bilirubin activity) and LDH (LDH-1 & LDH-5) isoenzyme profiles can be very helpful in defining the border of the liver injury, dieldrin damaged liver would be a valuable addition to histological analysis in evaluating histopathological liver changes.