Screening of newborn infants for cholestatic hepatobiliary disease with tandem mass spectrometry

Differences in bile acid profiles between cholestatic diseases - Development of a high throughput assay for dried bloodspots

BACKGROUND

Cholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile. Quantification of circulating BAs in dried bloodspots (DBS) may demonstrate obstruction of bile flow and altered bile acid metabolism in the liver. High sample throughput enables rapid screening of cholestatic diseases.

MATERIALS AND METHODS

Ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used for optimizing separation and detection of the primary unconjugated BAs cholic acid (CA) and chenodeoxycholic acid (CDCA); the secondary unconjugated BAs ursodeoxycholic acid (UDCA), hyodeoxycholic acid (HDCA) and deoxycholic acid (DCA), as well as the glycine- and taurine-conjugated variants of CA, CDCA, DCA and UDCA. Donor blood was obtained to prepare DBS calibrators and quality controls for method development and validation.

RESULTS

We developed a quantitative bile acid assay with a run-time of two minutes, and one-step sample preparation of 3.2 mm DBS discs. Validation results demonstrated overall good performance and was considered fit for purpose. Children with Alagille syndrome, Aagenaes syndrome and alpha-1 antitrypsin deficiency had increased BAs in DBS from newborn screening samples compared with age matched controls, and had different bile acids profiles.

CONCLUSION

We propose that our high throughput assay allows bile acid profiling in DBS that can be a valuable assessment tool for early screening of cholestasis in children. Assaying BAs in dried bloodspots is key for early detection of cholestasis, and provides transferability to a newborn screening setting.

Multiscale X-ray phase-contrast CT unveils the evolution of bile infarct in obstructive biliary disease

Bile infarct is a pivotal characteristic of obstructive biliary disease, but its evolution during the disease progression remains unclear. Our objective, therefore, is to explore morphological alterations of the bile infarct in the disease course by means of multiscale X-ray phase-contrast CT. Bile duct ligation is performed in mice to mimic the obstructive biliary disease. Intact liver lobes of the mice are scanned by phase-contrast CT at various resolution scales. Phase-contrast CT clearly presents three-dimensional (3D) images of the bile infarcts down to the submicron level with good correlation with histological images. The CT data illustrates that the infarct first appears on day 1 post-BDL, while a microchannel between the infarct and hepatic sinusoids is identified, the number of which increases with the disease progression. A 3D model of hepatic acinus is proposed, in which the infarct starts around the portal veins (zone I) and gradually progresses towards the central veins (zone III) during the disease process. Multiscale phase-contrast CT offers the comprehensive analysis of the evolutionary features of the bile infarct in obstructive biliary disease. During the course of the disease, the bile infarcts develop infarct-sinusoidal microchannels and gradually occupy the whole liver, promoting the disease progression.

Diseases of bile duct in children

Several diseases originate from bile duct pathology. Despite studies on these diseases, certain etiologies of some of them still cannot be concluded. The most common disease of the bile duct in newborns is biliary atresia, whose prognosis varies according to the age of surgical correction. Other diseases such as Alagille syndrome, inspissated bile duct syndrome, and choledochal cysts are also time-sensitive because they can cause severe liver damage due to obstruction. The majority of these diseases present with cholestatic jaundice in the newborn or infant period, which is quite difficult to differentiate regarding clinical acumen and initial investigations. Intraoperative cholangiography is potentially necessary to make an accurate diagnosis, and further treatment will be performed synchronously or planned as findings suggest. This article provides a concise review of bile duct diseases, with interesting cases.

Analysis of Metabolic Changes in Endogenous Metabolites and Diagnostic Biomarkers for Various Diseases Using Liquid Chromatography and Mass Spectrometry

Analysis of endogenous metabolites in various diseases is useful for searching diagnostic biomarkers and elucidating the molecular mechanisms of pathophysiology. The author and collaborators have developed some LC/tandem mass spectrometry (LC/MS/MS) methods for metabolites and applied them to disease-related samples. First, we identified urinary conjugated cholesterol metabolites and serum N-palmitoyl-O-phosphocholine serine as useful biomarkers for Niemann-Pick disease type C (NPC). For the purpose of intraoperative diagnosis of glioma patients, we developed the LC/MS/MS analysis methods for 2-hydroxyglutaric acid or cystine and found that they could be good differential biomarkers. For renal cell carcinoma, we searched for various biomarkers for early diagnosis, malignancy evaluation and recurrence prediction by global metabolome analysis and targeted LC/MS/MS analysis. In pathological analysis, we developed a simultaneous LC/MS/MS analysis method for 13 steroid hormones and applied it to NPC cells, we found 6 types of reductions in NPC model cells. For non-alcoholic steatohepatitis (NASH), model mice were prepared with special diet and plasma bile acids were measured, and as a result, hydrophilic bile acids were significantly increased. In addition, we developed an LC/MS/MS method for 17 sterols and analyzed liver cholesterol metabolites and found a decrease in phytosterols and cholesterol synthetic markers and an increase in non-enzymatic oxidative sterols in the pre-onset stage of NASH. We will continue to challenge themselves to add value to clinical practice based on cutting-edge analytical chemistry methodology.

A Pilot Study of Biliary Atresia Newborn Screening Using Dried Blood Spot Matrix Metalloproteinase-7

OBJECTIVES

Timely diagnosis is a critical challenge and is associated with improved survival of biliary atresia (BA) patients. We aimed to measure matrix metalloproteinase-7 (MMP-7) levels in BA patients within 3 days of birth using the dried blood spot (DBS) method and evaluate its potential as a screening tool.

METHODS

The study enrolled 132 patients, including 25 patients diagnosed with BA and 107 non-BA patients with other congenital or perinatal conditions from the National Taiwan University Children Hospital. The stored DBS samples collected from 48 to 72 hours of life were retrieved from newborn screening centers. MMP-7 on the DBS was quantified using a sensitive sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

The MMP-7 levels of BA patients on the DBS were significantly higher than those of non-BA patients (19.2 ± 10.4 vs 5.6 ± 2.7 ng/mL, P value < 0.0001). MMP-7 levels in non-BA patients, including 5 patients with hepatobiliary structural anomaly, 9 patients with intrahepatic cholestasis, and 93 patients with other perinatal diseases, were 11.6 ± 4.2 ng/mL, 6.9 ± 3.0 ng/mL, and 5.2 ± 2.1 ng/mL, respectively. The DBS MMP-7 level showed good accuracy for identifying BA, with an area under the curve of 93.7% [95% confidence interval (CI): 87.7%-99.7%]. The MMP-7 cutoff at 8.0 ng/mL showed a sensitivity of 92.0% (95% CI: 75.0%-98.6%) and specificity of 92.5% (95% CI: 85.9%-96.1%) for detecting BA from other congenital or perinatal diseases.

CONCLUSIONS

MMP-7 DBS analysis can be used to distinguish BA from other conditions as early as 3 days of age.

Population-based screening methods in biliary atresia: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate tested methods of population-based biliary atresia (BA) screening.

DESIGN

We searched 11 databases between 1 January 1975 and 12 September 2022. Data extraction was independently done by two investigators.

MAIN OUTCOME MEASURES

Our primary outcomes were: sensitivity and specificity of screening method in BA detection, age at Kasai, BA associated morbidity and mortality, cost-effectiveness of screening.

RESULTS

Six methods of BA screening were evaluated: stool colour charts (SCCs), conjugated bilirubin measurements, stool colour saturations (SCSs), measurements of urinary sulfated bile acids (USBAs), assessments of blood spot bile acids and blood carnitine measurements.In a meta-analysis, USBA was the most sensitive and specific, with a pooled sensitivity and specificity of 100.0% (95% CI 2.5% to 100.0%) and 99.5% (95% CI 98.9% to 99.8%) (based on one study). This was followed by conjugated bilirubin measurements: 100.0% (95% CI 0.0% to 100.0%) and 99.3% (95% CI 91.9% to 99.9%), SCS: 100.0% (95% CI 0.00% to 100.0%) and 92.4% (95% CI 83.4% to 96.7%), and SCC: 87.9% (95% CI 80.4% to 92.8%) and 99.9% (95% CI 99.9% to 99.9%).SCC reduced the age of Kasai to ~60 days, compared with 36 days for conjugated bilirubin. Both SCC and conjugated bilirubin improved overall and transplant-free survival. The use of SCC was considerably more cost-effective than conjugated bilirubin measurements.

CONCLUSION

Conjugated bilirubin measurements and SCC are the most researched and demonstrate improved sensitivity and specificity in detecting BA. However, their use is expensive. Further research into conjugated bilirubin measurements, as well as alternative methods of population-based BA screening, is required.

PROSPERO REGISTRATION NUMBER

CRD42021235133.

The value of blood and urine metabolomics in differential diagnosis of cholestasis in infants

Background

Early detection of biliary atresia (BA) is a great challenge providing the main useful way to improve its clinical consequence. Promising metabolomics provides an effective method for determining innovative biomarkers and biochemical ways for improving early diagnosis. This study aimed to determine the benefit of serum and urinary potential bile acid metabolites in the differentiation of BA from non-biliary atresia (non-BA) cases using tandem mass spectrometry (MS/MS). Fourteen bile acids metabolites were measured quantitively by MS/MS in serum and urine samples from 102 cholestatic infants and 102 control infants, in addition to the assay of the total serum bile acid enzymatically.

Results

After the diagnostic clinical and laboratory workflow, cholestatic infants were divided into BA (37 infants) and non-BA (65 infants) subgroups. Remarkably on analysis of serum individual bile acid concentrations, there were significant differences between cholestatic BA and non-BA regarding serum (glycocenodeoxycholic acid (GCDCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), and GCDCA/chenodeoxycholic acid (CDCA) ratio) (p < 0.001, for all), while there was no significant difference between the two groups regarding serum level of (cholic acid (CA), glycocholic (GCA), or TCDCA/CDCA ratio). There were no significant differences in either the urinary individual bile acids or urinary primary bile acids (conjugated or unconjugated) between BA and non-BA. Further principal component analysis (PCA) analysis was done and receiver operating characteristic (ROC) analysis was performed using score plots of the positive factors in the first two principal components PC1 (CA, GCA, GCDCA, TCA, TCDCA) and PC2 (CA, CDCA, lithocholic (LCA), ursodeoxycholic acid (UDCA)) for establishing the differences between the two diseased groups and revealed that the area under the curve (AUC) for PC1 was (0.770) higher than AUC for PC2 (0.583) indicating that the positive components of PC1 may be potential biomarkers for differentiation between the two cholestatic groups.

Conclusions

Metabolomics of serum bile acid levels using tandem mass spectrometry might change the paradigm differentiating BA from non-BA saving patients from unnecessary invasive procedures.

Newborn Screening for Biliary Atresia: a Review of Current Methods

PURPOSE OF REVIEW

Biliary atresia is a serious neonatal liver disease due to obstructed bile ducts that has better outcomes when detected and treated in the first 30-45 days of life. This review examines different methods to screen newborns for biliary atresia as well as discusses observations from ongoing screening programs implemented in parts of the United States.

RECENT FINDINGS

Screening strategies for biliary atresia include detecting persistent jaundice, examining stool color, testing fractionated bilirubin levels, or measuring bile acid levels from dried blood spot cards. The stool color card program is the most widely used screening strategy worldwide. An alternative approach under investigation in the United States measures fractionated bilirubin levels, which are abnormal in newborns with biliary atresia. Fractionated bilirubin screening programs require laboratories to derive reference ranges, nurseries to implement universal testing, and healthcare systems to develop infrastructure that identifies and acts upon abnormal results. Biliary atresia meets the disease-specific criteria for newborn screening. Current studies focus on developing a strategy which also meets all test-specific criteria. Such a strategy, if implemented uniformly, has the potential to accelerate treatment and reduce biliary atresia's large liver transplant burden.

Biliary atresia: Potential for a new decade

Biliary atresia is characterised as an obliterative cholangiopathy of both extra-and intra-hepatic bile ducts. There is marked aetiological heterogeneity with a number of different variants, some syndromic and others perhaps virally-mediated. Current research aims to try and define possible mechanisms and pathogenesis though an actual breakthrough remains elusive. There has been little in the way of surgical advances beyond subtle variations in the Kasai portoenterostomy and laparoscopic equivalents have no declared advantage and have yet to prove equivalence in measures of outcome. The next target has been to maximise potential with better adjuvant therapy, though the evidence base for most currently available therapies such as steroids and ursodeoxycholic acid remains limited. Still high-dose steroid use is widespread, certainly in Europe and the Far East. Clearance of jaundice can be achieved in 50-60% of those subjected to portoenterostomy at <70 days and should be an achievable benchmark. Transplantation is a widely available "rescue" therapy though whether it should be an alternative as a primary procedure is arguable but becoming increasingly heard. The aim of clinical practice remains to get these infants for surgery as early as is possible though this can be difficult to accomplish in practice, and "low-cost" screening projects using stool colour charts have been limited outside of Taiwan and Japan. Centralisation of resources (medical and surgical) is associated with a diminution of time to portoenterostomy but application has been limited by entrenched health delivery models or geographical constraints.

Serum bile acids profiling by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application on pediatric liver and intestinal diseases

Background

A method for bile acid profiling measuring 21 primary and secondary bile acids in serum samples was developed and validated with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample preparation included spiking with internal standards followed by protein precipitation, centrifugation, drying under nitrogen gas and reconstitution. Extracted samples were injected onto a Phenomenex Kinetex C18 column (150 × 4.60 mm, 2.6 μm).

Methods

Data was collected with LC-MS/MS operated in negative ion mode with multiple reaction monitoring (MRM) and single reaction monitoring (SRM). The analytical run time was 12 min.

Results

The method showed excellent linearity with high regression coefficients (>0.99) over a range of 0.05 and 25 μM for all analytes tested. The method also showed acceptable intra-day and inter-day accuracy and precision. As a proof of concept, the analytical method was applied to patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), biliary atresia (BA), and necrotizing enterocolitis (NEC), and distinct bile acids profiles were demonstrated.

Conclusions

The method could be poised to identify possible biomarkers for non-invasive early diagnosis of these disorders.

Gut microbial profile in biliary atresia: a case-control study

BACKGROUND AND AIM

Biliary atresia (BA) is a progressive fibro-inflammatory cholangiopathy with an unclear etiology. Various liver disorders are associated with an altered microbiome. However, gut microbiome in BA remains unknown. Here, we performed a case-control study to investigate the gut microbiota in BA.

METHODS

A cross-sectional analysis was first conducted for 34 BA patients and 34 healthy controls. Then we investigated the shift in gut microbiota 2 weeks after the Kasai procedure in 16 BA patients. Gut microbiome was initially analyzed using 16S ribosome RNA gene sequencing and further validated by metagenomic sequencing. Fecal bile acids were determined using ultra-high performance liquid chromatography.

RESULTS

Compared with healthy controls, BA showed lower diversity and significant structural segregation in the microbiome. At phylum level, Proteobacteria numbers increased, whereas those of Bacteroidetes decreased in BA. At genus level, several potential pathogens such as Streptococcus and Klebsiella thrived in BA, while numbers for Bifidobacterium and several butyrate-producing bacteria declined. The microbiome was also disturbed after the Kasai procedure. Operational taxonomic units responding to BA showed significant correlation with liver function. Furthermore, the abundance ratio of Streptococcus/Bacteroides showed great promise in distinguishing BA from healthy controls. Intestinal bile acids were dramatically decreased in BA, and Clostridium XIVa positively correlated with the ratio of primary/secondary bile acids.

CONCLUSIONS

Gut microbial dysbiosis, may be caused by decreased bile acids, was associated with liver function and had a good diagnostic potential for BA. Therefore, further exploration of gut microbiota may provide important insights into their potential diagnostic and therapeutic benefits.

Inborn Errors of Bile Acid Metabolism

Inborn errors of bile acid metabolism are rare causes of neonatal cholestasis and liver disease in older children and adults. The diagnosis should be considered in the context of hyperbilirubinemia with normal serum bile acids and made by urinary liquid secondary ionization mass spectrometry or DNA testing. Cholic acid is an effective treatment of most single-enzyme defects and patients with Zellweger spectrum disorder with liver disease.

Newborn biliary atresia screening with the stool colour card: a questionnaire survey of parents

PURPOSE

Biliary atresia can easily be screened using a stool colour card (SCC) and has shown to significantly reduce time to diagnosis, improving children's outcome. Despite the general approval of the clinical usefulness of the SCC, physicians remain reluctant: it might unnecessarily worry parents. This study aimed to analyse the parental reaction to this screening method and if it evokes parental stress.

METHODS

A semistructured questionnaire was sent to parents with one or more healthy child to inquire about reactions on receipt and use of the SCC.

RESULTS

109/256 questionnaires were returned and evaluated (43%). 107/107 parents considered the SCC as helpful, a simple screening method and easy to use (100%). 26/43 were reassured when receiving the SCC (60%), 2 were worried (5%) and 9 had no particular feelings (21%). In 41/49, emotions experienced during its use were positive or neutral (84%), and 3 were worried (6%). In 41/50, the discussion with the paediatrician about stool colour-linked pathologies was neutral (82%), and 9 felt uneasy (18%).

CONCLUSION

A vast majority of parents appreciate the SCC. It creates uneasiness in a minority of parents. Our results are encouraging and argue in favour of implementing the regular distribution of the SCC in antenatal, postnatal and newborn infant clinics.

Screening for biliary atresia

Early diagnosis followed by proper KP is essential for the improvement of long-term prognosis for patients with BA. It is increasingly accepted that KP at ≤ 30 days of age significantly improves native liver survival rate. Published analyses in English and Japanese indicate that screening by SCC and DB/CB is potentially feasible. Screening with SCC has been implemented in Tochigi Prefecture, Japan, since 1994. The concept of SCC was introduced from Japan to Taiwan and resulted in nationwide screening with SCC for the first time in Taiwan in 2004, followed by Japan in 2012. Home-based screening using SCC is easy and cost-effective; however, it may cause some difficulties for families in case of stools with intermediate colors. Laboratory-based screening using DB/CB may detect the suspected cases earlier, resulting in an increase in the number of patients with BA who undergo KP at ≤ 30 days of age; however, the recall rate is 1% and may be beyond an acceptable range. Further studies are needed to assess the feasibility and cost-effectiveness of both home-based (SCC) and laboratory-based (DB/CB) screening for BA.

Referral Patterns and Factors Influencing Age at Admission of Infants with Cholestasis in India

OBJECTIVES

To define the recognition, age at admission, referral time and referral pattern of neonatal cholestasis in India.

METHODS

This prospective, observational study was conducted from February 2015 through March 2016 in the Pediatric gastroenterology unit of JIPMER, Pondicherry in infants with cholestasis < 6 mo of age.

RESULTS

Among 64 infants, median age of admission was 52 d (IQR 28-63 d). Fifty of sixty four infants (78.1%) came with parent-reported cholestasis-related symptoms of either jaundice alone (57.8%) or bleeding manifestations (20.3%). In 21.9% infants, jaundice was detected by physicians at a median age of 45 d (IQR 38.5-53.2 d). Two infants had intracranial bleed. Only 34% infants with pale stools were identified by the mother. The median healthcare-seeking time was 5.5 d (IQR 2.5-12 d). Among infants presenting to primary healthcare physicians (PHPs) with cholestasis-related symptoms, median time to referral was 5 d (IQR 2.5-12 d). The first point of healthcare contact in 54.7% was a PHP; 17.1% PHPs had reassured the parents. Herbal preparations were prescribed by 14.3%. Only 11.8% of those with jaundice as the only problem were given vitamin K before referral. Biliary atresia (BA) was missed in neonatal intensive care units in 9 cases.

CONCLUSIONS

The above issues need to be accounted for before evaluating or implementing screening strategies in India.

Biliary atresia: From Australia to the zebrafish

This review is based upon an invited lecture for the 52nd Annual Meeting of the British Association of Paediatric Surgeons, July 2015. The aetiology of biliary atresia (BA) is at best obscure, but it is probable that a number of causes or pathophysiological mechanisms may be involved leading to the final common phenotype we recognise clinically. By way of illustration, similar conditions to human BA are described, including biliary agenesis, which is the normal state and peculiar final pattern of bile duct development in the jawless fish, the lamprey. Furthermore, there have been remarkable outbreaks in the Australian outback of BA in newborn lambs whose mothers were exposed to and grazed upon a particular plant species (Dysphania glomulifera) during gestation. More recent work using a zebrafish model has isolated a toxic isoflavonoid, now named Biliatresone, thought to be responsible for these outbreaks. Normal development of the bile ducts is reviewed and parallels drawn with two clinical variants thought to definitively have their origins in intrauterine life: Biliary Atresia Splenic Malformation syndrome (BASM) and Cystic Biliary Atresia (CBA). For both variants there is sufficient clinical evidence, including associated anomalies and antenatal detection, respectively, to warrant their aetiological attribution as developmental BA. CMV IgM +ve associated BA is a further variant that appears separate with distinct clinical, histological, and immunohistochemical features. In these it seems possible that this involves perinatal obliteration of a normally formed duct system. Although still circumstantial, this evidence appears convincing enough to perhaps warrant a different treatment strategy. This then still leaves the most common (more than 60% in Western series) variant, now termed Isolated BA, whereby origins can only be alluded to.

Effects of age at Kasai portoenterostomy on the surgical outcome: a review of the literature

The efficacy of early Kasai portoenterostomy has been repeatedly reported. However, the optimal age for performing this procedure remains controversial. This article reviews the literature on the age of patients at the time of Kasai portoenterostomy and its utility as a prognostic indicator. The age at the time of surgery is a known predictor of outcome; however, its exact predictive value in this context is unclear. Multicenter studies involving large volumes of data have tended to show advantages of early Kasai portoenterostomy, and there is no clear evidence to recommend any delay in the timing of surgery. At present, a reasonable strategy would be to perform a Kasai portoenterostomy as early as possible. The stool color card system has recently been implemented in Japan as part of a nationwide screening program, and it is expected to work well based on the early reports. However, efforts to identify an optimal screening system for ensuring the earliest diagnosis of biliary atresia should continue. An early diagnosis of biliary atresia is difficult, and global efforts are required to improve the early diagnosis rates.

Home-based screening for biliary atresia using infant stool colour cards: a large-scale prospective cohort study and cost-effectiveness analysis

OBJECTIVE

Biliary atresia (BA), a leading cause of paediatric liver failure and liver transplantation, manifests by three weeks of life as jaundice with acholic stools. Poor outcomes due to delayed diagnosis remain a problem worldwide. We evaluated and assessed the cost-effectiveness of methods of introducing a BA Infant Stool Colour Card (ISCC) screening programme in Canada.

SETTING AND METHODS

A prospective study at BC Women's Hospital recruited consecutive healthy newborns through six incrementally more intensive screening approaches. Under the baseline "passive" strategy, families received ISCCs at maternity, with instructions to monitor infant stool colour daily and return the ISCC by mail at age 30 days. Additional strategies were: ISCC mailed to family physician; reminder letters or telephone calls to families or physicians. Random telephone surveys of ISCC non-returners assessed total card utilization. Primary outcome was ISCC utilization rate expressed as a composite outcome of the ISCC return rate and non-returned ISCC use. Markov modelling was used to predict incremental costs and life years gained from screening (passive and reminder), compared with no screening, over a 10-year time horizon.

RESULTS

6,187 families were enrolled. Card utilization rates in the passive screening strategy were estimated at 60-94%. For a Canadian population, the increase in cost for passive screening, compared with no screening, is $213,584 and the gain in life years is 9.7 ($22,000 per life-year gained).

CONCLUSIONS

A BA ISCC screening programme targeting families of newborns is feasible in Canada. Passive distribution of ISCC at maternity is potentially effective and highly cost-effective.

Identification of the plasma metabolomics as early diagnostic markers between biliary atresia and neonatal hepatitis syndrome

Early detection is the most effective way to improve the clinical outcome of biliary atresia (BA). Emerging metabolomics provides a powerful platform for discovering novel biomarkers and biochemical pathways to improve early diagnosis. The aim of this study is to find the potential biomarkers to distinguish BA from neonatal hepatitis syndrome (NHS) by using a metabolomics method. We comprehensively analyzed the serum metabolites in a total of 124 blood samples from patients with BA or neonatal hepatitis syndrome (NHS) and from normal individuals using advanced metabolomic approaches, and found that the levels of glutarylcarnitine (C5DC) significantly increased in the BA group while the levels of threonine (Thr) significantly rose in the NHS group comparing with the other groups. The levels of glutamic acid (Glu) in the BA group were significantly elevated compared to those in the NHS group, but still lower than the hyperbilirubinemia and normal controls. The levels of propionyl carnitine (C3), isovaleryl carnitine (C5) and glutamine (Gln) were reduced in the BA group compared to those in the NHS group, but still higher than the hyperbilirubinemia and normal controls. This study demonstrates the possibility of metabolomics as non-invasive biomarkers for the early detection of BA and also provides new insight into pathophysiologic mechanisms for BA.

Aspiration and allograft injury secondary to gastroesophageal reflux occur in the immediate post-lung transplantation period (prospective clinical trial)

OBJECTIVES

To provide novel pilot data to quantify reflux, aspiration, and allograft injury immediately post-lung transplantation.

BACKGROUND

Asymptomatic reflux/aspiration, associated with allograft dysfunction, occurs in lung transplant recipients. Early fundoplication has been advocated. Indications for surgery include elevated biomarkers of aspiration (bile salts) in bronchoalveolar lavage fluid (BALF). Measurements have been mostly documented after the immediate posttransplant period. We report the first prospective study of reflux/aspiration immediately posttransplantation to date.

METHODS

Lung transplant recipients were recruited over 12 months. At 1 month posttransplantation, patients completed a Reflux Symptom Index questionnaire and underwent objective assessment for reflux (manometry and pH/impedance). Testing was performed on maintenance proton pump inhibitor. BALF was assessed for pepsin, bile salts, interleukin-8 and neutrophils.

RESULTS

Eighteen lung transplant recipients, median age of 46 years (range: 22-59 years), were recruited. Eight of 18 patients had abnormal esophageal peristalsis. Five of 17 patients were positive on Reflux Symptom Index questionnaire. Twelve of 17 patients had reflux. Three patients exclusively had weakly acid reflux. Median acid exposure was 4.8% (range: 1%-79.9%) and median esophageal volume exposure was 1.6% (range: 0.7-5.5). There was a median of 72 reflux events (range: 27-147) per 24 hours. A correlation existed between Reflux Symptom Index score and proximal reflux (r = 0.533, P = 0.006). Pepsin was detected in 11 of 15 BALF samples signifying aspiration (median: 18 ng/mL; range: 0-43). Bile salts were undetectable, using spectrophotometry and rarely detectable using dual mass spectrometry (2/15) (levels 0.2 and 1.2 μmol/L). Lavage interleukin-8 and neutrophil levels were elevated. A correlation existed between proximal reflux events and neutrophilia (r = 0.52, P = 0.03).

CONCLUSIONS

Lung transplant recipients should be routinely assessed for reflux/aspiration within the first month posttransplant. Reflux/aspiration can be present early postoperatively. Pepsin was detected suggesting aspiration. Bile salts were rarely detected. Proximal reflux events correlated with neutrophilia, linked to allograft dysfunction and mortality. These results support the need for early assessment of reflux/aspiration, which may inform fundoplication.

LC/ESI-MS/MS analysis of urinary 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its amides: new biomarkers for the detection of Niemann-Pick type C disease

We developed a sensitive, reliable, and accurate LC/ESI-MS/MS method for measurement of 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its glycine and taurine amides in urine. This atypical C24 bile acid has been reported previously to be present in the urine of patients with Niemann-Pick Type C (NPC) disease. In the method, targeted analytes are concentrated at the front edge of a trapping column, Shim-pack MAYI-C8, which permits elimination of contaminating molecules in the urinary matrix. The trapped analytes are then eluted, separated on a YMC-Pack Pro C18, and quantified with MS/MS using selected reaction monitoring. The method could detect (as amount injected) 2pg of nonamidated 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid, 2pg of its glycine-amide, and 0.6pg of its taurine-amide, and is linear up to 300pg. The method was then used to measure the three analytes in the urine of NPC patients (N=2), 3β-hydroxysteroid dehydrogenase deficiency patients (N=2), and healthy volunteers (N=8). Measurable concentrations of all three analytes were present in all subjects. The urinary concentration of the sum of all three analytes was four hundred times greater in the 3month NPC patient and 40times greater in the adult patient than that of healthy volunteers. The markedly elevated urinary concentration of 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its amides in NPC patients suggests that these compounds may be valuable biomarkers for detection of NPC disease.

Aetiology of biliary atresia: what is actually known?

Biliary atresia (BA) is a rare disease of unknown etiology and unpredictable outcome, even when there has been timely diagnosis and exemplary surgery. It has been the commonest indication for liver transplantation during childhood for the past 20 years. Hence much clinical and basic research has been directed at elucidating the origin and pathology of BA. This review summarizes the current clinical variations of BA in humans, its occasional appearance in animals and its various manifestations in the laboratory as an experimental model.

International incidence and outcomes of biliary atresia

OBJECTIVES

International trends in incidence and outcomes of biliary atresia (BA) are controversial and a wide range of estimates have been reported worldwide. We reviewed the population-based literature to assess international variation of BA incidence and outcomes, and to assess the evidence for seasonal variation in incidence, centralization of Kasai hepatoportoenterostomy, and newborn screening.

METHODS

We conducted a systematic review (registration number CRD42011001441) of observational or interventional research within MEDLINE, EMBASE, and the Cochrane Database, which reported incidence, prevalence, or outcomes of infants with BA. Population-based studies, defined by inclusion of an entire population or representative sample, were included. Outcomes included overall survival, native liver survival (NLS), and time to Kasai hepatoportoenterostomy. Single- or multicenter studies were excluded unless those centers captured all potential patients within a jurisdiction. Two independent data extractors reviewed the abstracts and articles.

RESULTS

A total of 40 studies were included following review of 3128 references. A wide range of incidence was reported internationally. Ten-year overall survival ranged from 66.7% to 89%. NLS ranged from 20.3% to 75.8% at 1 to 3 years and 24% to 52.8% at 10 years. Earlier age at Kasai was a predictor of improved NLS. Seasonality was reported in 11 studies, and 3 reported an increased incidence during the months of August to March. The evidence for centralization of Kasai to high-volume centers is promising but does not account for all case-mix, provider, or health system factors involved in volume-outcome relations. Stool color card screening resulted in earlier Kasai and improved NLS in Taiwan.

CONCLUSIONS

Large, international studies could help fill the gaps in knowledge identified by this review.

Biliary atresia: 50 years after the first kasai

Biliary atresia is a rare neonatal disease of unknown etiology, where obstruction of the biliary tree causes severe cholestasis, leading to biliary cirrhosis and death in the first years of life, if the condition is left untreated. Biliary atresia is the most frequent surgical cause of cholestatic jaundice in neonates and should be evoked whenever this clinical sign is associated with pale stools and hepatomegaly. The treatment of biliary atresia is surgical and currently recommended as a sequence of, eventually, two interventions. During the first months of life a hepatoportoenterostomy (a "Kasai," modifications of which are discussed in this paper) should be performed, in order to restore the biliary flow to the intestine and lessen further damage to the liver. If this fails and/or the disease progresses towards biliary cirrhosis and life-threatening complications, then liver transplantation is indicated, for which biliary atresia represents the most frequent pediatric indication. Of importance, the earlier the Kasai is performed, the later a liver transplantation is usually needed. This warrants a great degree of awareness of biliary atresia, and the implementation of systematic screening for this life-threatening pathology.

Elevated bile acids in newborns with Biliary Atresia (BA)

Biliary Atresia (BA), a result from inflammatory destruction of the intrahepatic and extrahepatic bile ducts, is a severe hepatobiliary disorder unique to infancy. Early diagnosis and Kasai operation greatly improve the outcome of BA patients, which encourages the development of early screening methods. Using HPLC coupled tandem mass spectrometry, we detected primary bile acids content in dried blood spots obtained from 8 BA infants, 17 neonatal jaundice and 292 comparison infants at 3–4 days of life. Taurocholate (TC) was significantly elevated in biliary atresia infants (0.98±0.62 µmol/L) compared to neonatal jaundice (0.47±0.30 µmol/L) and comparison infants (0.43±0.40 µmol/L), with p = 0.0231 and p = 0.0016 respectively. The area under receiver operating characteristic (ROC) curve for TC to discriminate BA and comparison infants was 0.82 (95% confidence interval: 0.72–0.92). A cutoff of 0.63 µmol/L produced a sensitivity of 79.1% and specificity of 62.5%. The concentrations of total bile acids were also raised significantly in BA compared to comparison infants (6.62±3.89 µmol/L vs 3.81±3.06 µmol/L, p = 0.0162), with the area under ROC curve of 0.75 (95% confidence interval: 0.61–0.89). No significant difference was found between the bile acids of neonatal jaundice and that of comparison infants. The early increase of bile acids indicates the presentation of BA in the immediate newborn period and the possibility of TC as newborn screening marker.

Early detection of biliary atresia: past, present & future

The age threshold at the time of Kasai hepatic portoenterostomy associated with a prognosis of biliary atresia (BA) is becoming clearer as 10-year native liver survival data become more frequent in the recent literature, whereas the age at diagnosis has not dramatically decreased during the last 3 decades. A stool color card screening implemented in 1994 in Japan is now expanding worldwide. However, the contribution of this modality will probably be limited because of the nature of this disease, for example, 'progressive obliterative cholangiopathy'. A cholic stool was actually observed only in 50% before diagnosis according to the Japanese BA Registry data. Thus, color card screening does not appear to be instrumental in detecting patients with BA early enough before 1 month of age. A highly sensitive, adequately specific, noninvasive and quantitative method may be expensive, but the overall cost would be lower than that of liver transplant.

Rationalized assessment of prolonged jaundice is safe and cost-effective

Prolonged jaundice (PJ) in healthy term neonates is common and frequently benign. It can, however, be the earliest manifestation of underlying liver disease. Its management requires a balanced approach, avoiding over-investigation of well babies while ensuring the early identification of those with pathology. Currently marked heterogeneity exists in the assessment of PJ. Over a two-year period we prospectively audited the management of PJ in two Level 3 neonatal units prior to and after the introduction of a rationalized investigation algorithm in keeping with the recently published British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) guidelines (i.e. clinical examination and stool inspection combined with measurement of split bilirubin). In this study we reviewed initial practice and then evaluated the impact of our change in practice. A total of 197 babies, 1.5% of live births, were referred with PJ. Of these, 105 babies were included in the first part of the study and 92 babies were included in the second part. No pathology relating to PJ, such as infection, hepatitis or liver disease, was identified. Following the introduction of our rationalized algorithm, we demonstrated a statistically significant reduction in the number of return appointments (28 versus 7; P < 0.0009) and repeat investigations (37 versus 7; P < 0.0001). This represented a saving of £1575-2625 per year in laboratory costs alone. Contemporaneously, three infants presented with biliary atresia, none of whom were identified by PJ screening and all of whom were over seven weeks old at diagnosis. A rationalized approach to the assessment of PJ reduces workload and is cost-effective; however, the limitations of selective screening, irrespective of how streamlined it is, remain--if babies are not identified and referred, they cannot be screened. Population-based methodologies offer an alternative approach to the identification of cholestatic liver disease and are worthy of further consideration.

Biliary atresia: clinical aspects

Biliary atresia (BA) remains an enigmatic disease with a degree of etiologic heterogeneity. A number of variants can be defined clinically, and these include the syndromic group (typically BA splenic malformation), cystic BA, and cytomegalovirus (CMV) IgM +ve associated BA. The remainder, and still the largest group, may be termed isolated BA(.) There is a wide variation in incidence across the globe from 1 in 5000 in Taiwan to 1 in 20,000 live births in Northern Europe, although the reasons for such a disparity remain obscure. Management remains primarily surgical with an attempt to restore bile flow by resection of extrahepatic biliary remnants and a reconstruction portoenterostomy (the Kasai procedure), reserving liver transplantation for those where this fails or complications of chronic liver disease supervene. Clearance of jaundice to normal values has been achieved in 40%-55% of cases in large series from around the world, with an expectation of 5-year native liver survival of similar proportions.

Neonatal cholestasis: opportunities to increase early detection

OBJECTIVE

To describe primary care management of early and prolonged jaundice in otherwise-healthy term infants to identify opportunities to increase early diagnosis of cholestasis.

METHODS

Community-based pediatricians in St Louis, Missouri completed a mailed, anonymous, 29-item survey to assess practice demographics, timing of routine newborn office visits, and the management of early and prolonged neonatal jaundice.

RESULTS

A total of 108 of 230 (47%) of eligible physicians responded (mean years in practice, 15.3, SD, 9.4). More respondents were very familiar with national guidelines for management of early (49%) than prolonged (16%) neonatal jaundice. Eighty-six percent reported all newborns were checked with transcutaneous bilirubin before hospital discharge. For transcutaneous bilirubin results at 48 hours of 7, 10, 12 and 15 mg/dL, 1%, 26%, 70%, and 74% of respondents, respectively, would order a fractionated bilirubin. Although the first routine visit usually occurred in the first week after discharge, 25% of physicians reported the 2nd visit was routinely scheduled after 4 weeks of age. Ninety-four percent reported they would obtain a fractionated bilirubin for infants jaundiced beyond 4 weeks of age. If cholestasis was identified at 6 weeks of age, 32% would obtain additional testing without referral to a subspecialist.

CONCLUSIONS

Management of early and prolonged neonatal jaundice is variable. Current practices appear to miss opportunities for early diagnosis of cholestasis and referral that are unlikely to be addressed without redesigning systems of care.

Patients with biliary atresia have elevated direct/conjugated bilirubin levels shortly after birth

OBJECTIVES

Healthy infants are thought to acquire biliary atresia (BA) in the first weeks of life. Because those diagnosed earlier have better outcomes, we were interested in determining the earliest time BA could be detected. We started by examining the immediate postnatal period, hypothesizing that newborns would not yet have acquired disease and still have normal direct/conjugated bilirubin (DB/CB) levels.

PATIENTS AND METHODS

Newborn DB/CB levels were obtained retrospectively from birth hospitals. Subjects with BA were born between 2007 and 2010 and cared for at Texas Children's Hospital. Those with BA splenic malformation syndrome or born prematurely were excluded. Control subjects were term newborns who later never developed neonatal liver disease.

RESULTS

Of the 61 subjects with BA, 56% had newborn DB/CB levels measured. All DB/CB levels exceeded laboratory norms and rose over time. At 24 to 48 hours of life, subjects with BA had mean DB levels significantly higher than those of controls (1.4 ± 0.43 vs. 0.19 ± 0.075 mg/dL, P < .0001), even while their mean total bilirubin (TB) levels remained below phototherapy limits. Finally, despite the elevated DB/CB levels, the majority of patients (79%) had normal DB:TB ratios ≤ 0.2.

CONCLUSIONS

Patients with BA have elevated DB/CB levels shortly after birth. To detect affected infants earlier and improve outcomes, the results suggest two possibilities: (1) screen all newborns for elevated DB/CB levels, rather than just those who appear jaundiced; and then (2) follow all newborns with elevated DB/CB levels, rather than just those with DB:TB ratios >0.2.

Titration of bile acid supplements in 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency

OBJECTIVES

3beta-Hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency is a bile acid synthesis defect responsive to primary bile acids. We reviewed its clinical features and response to treatment with a mixture of ursodeoxycholic (UDCA) and chenodeoxycholic acid (CDCA) to titrate the dose of supplements required for disease control.

PATIENTS AND METHODS

We studied our patients by liquid chromatography-tandem mass spectrometry, liver function tests, and histology. After diagnosis all of the patients received a balanced mixture of UDCA/CDCA and the dose was titrated according to urinary levels of 3beta,7 alpha-dihydroxy-5-cholenoic acid (u-3beta-D-OH-5C).

RESULTS

Five patients presenting with giant cell hepatitis, biliary cirrhosis, and cryptogenic cirrhosis (1 each), and picked up by neonatal screening (2 patients) were diagnosed at a median age of 2.5 years (range 0.1-5.5). Normal levels of u-3beta-D-OH-5C were achieved after 4 months (range 3-28 months) from the start of the treatment. The minimum dose of UDCA/CDCA required to maintain normal u-3beta-D-OH-5C levels was 5/5 mg x kg(-1) x day(-1). A follow-up biopsy in 2 patients showed no progression of liver disease.

CONCLUSIONS

A mixture of UDCA/CDCA can effectively control 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency. Dose titration by liquid chromatography-tandem mass spectrometry warrants the maintenance of negative feedback on the abnormal synthetic pathway and avoids disease progression.

Rapid quantification of conjugated and unconjugated bile acids and C27 precursors in dried blood spots and small volumes of serum

The aim of the study was to develop a method for fast and reliable diagnosis of peroxisomal diseases and to facilitate differential diagnosis of cholestatic hepatopathy. For the quantification of bile acids and their conjugates as well as C(27) precursors di- and trihydroxycholestanoic acid (DHCA, THCA), in small pediatric blood samples we combined HPLC separation on a reverse-phase C18 column with ESI-MS/MS analysis in the negative ion mode. Analysis was done with good precision (CV 3,7%-11.1%) and sufficient sensitivity (LOQ: 11-91 nmol/L) without derivatization. Complete analysis of 17 free and conjugated bile acids from dried blood spots and 10 microL serum samples, respectively, was performed within 12 min. Measurement of conjugated primary bile acids plus DHCA and THCA as well as ursodeoxycholic acid was done in 4.5 min. In blood spots of healthy newborns, conjugated primary bile acids were found in the range of 0.01 to 2.01 micromol/L. Concentrations of C(27) precursors were below the detection limit in normal controls. DHCA and THCA were specifically elevated in cases of peroxysomal defects and one Zellweger patient.

Bile acids: analysis in biological fluids and tissues

The formation of bile acids/bile alcohols is of major importance for the maintenance of cholesterol homeostasis. Besides their functions in lipid absorption, bile acids/bile alcohols are regulatory molecules for a number of metabolic processes. Their effects are structure-dependent, and numerous metabolic conversions result in a complex mixture of biologically active and inactive forms. Advanced methods are required to characterize and quantify individual bile acids in these mixtures. A combination of such analyses with analyses of the proteome will be required for a better understanding of mechanisms of action and nature of endogenous ligands. Mass spectrometry is the basic detection technique for effluents from chromatographic columns. Capillary liquid chromatography-mass spectrometry with electrospray ionization provides the highest sensitivity in metabolome analysis. Classical gas chromatography-mass spectrometry is less sensitive but offers extensive structure-dependent fragmentation increasing the specificity in analyses of isobaric isomers of unconjugated bile acids. Depending on the nature of the bile acid/bile alcohol mixture and the range of concentration of individuals, different sample preparation sequences, from simple extractions to group separations and derivatizations, are applicable. We review the methods currently available for the analysis of bile acids in biological fluids and tissues, with emphasis on the combination of liquid and gas phase chromatography with mass spectrometry.

Early diagnosis of neonatal cholestatic jaundice: test at 2 weeks

OBJECTIVE

To review best practices for early recognition and treatment of conditions resulting in neonatal cholestasis, in order to improve long-term outcomes for affected infants.

QUALITY OF EVIDENCE

Studies, review articles, and meta-analyses pertaining to neonatal-onset cholestasis were sought via electronic databases. Reference lists of studies and review articles supplemented the electronic search. Studies were included if they examined the importance of early diagnosis and intervention for cholestatic jaundice of any cause, and mainly comprised Level II and Level III evidence.

MAIN MESSAGE

Review of the relevant literature supports the recommendation that infants with jaundice at 2 weeks of age should be tested for cholestasis by quantifying the direct reacting bilirubin levels in their blood. Subsequent rapid investigation using a diagnostic algorithm enables early diagnosis of the specific cause and facilitates timely intervention for conditions whose outcomes are improved by early treatment.

CONCLUSION

Universal screening for neonatal cholestasis might help with early identification of cases and improve outcomes, although further study is required in the North American setting.

Biliary atresia

Biliary atresia is a rare disease of infancy, which has changed within 30 years from being fatal to being a disorder for which effective palliative surgery or curative liver transplantation, or both, are available. Good outcomes for infants depend on early referral and timely Kasai portoenterostomy, and thus a high index of suspicion is needed for investigation of infants with persistent jaundice. In centres with much experience of treating this disorder, up to 60% of children will achieve biliary drainage after Kasai portoenterostomy and will have serum bilirubin within the normal range within 6 months. 80% of children who attain satisfactory biliary drainage will reach adolescence with a good quality of life without undergoing liver transplantation. Although much is known about management of biliary atresia, many aspects are poorly understood, including its pathogenesis. Several hypotheses exist, implicating genetic predisposition and dysregulation of immunity, but the cause is probably multifactorial, with obliterative extrahepatic cholangiopathy as the common endpoint. Researchers are focused on identification of relevant genetic and immune factors and understanding serum and hepatic factors that drive liver fibrosis after Kasai portoenterostomy. These factors might become therapeutic targets to halt the inevitable development of cirrhosis and need for liver transplantation.

Biliary atresia: how medical complications and therapies impact outcome

Biliary atresia (BA) is a progressive fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction in the neonatal period. Untreated, BA is a uniformly fatal disease and, yet, even with our existing therapies, at least 50% of children with BA will undergo liver transplantation by the age of 2 years. Current treatment strategies are, at best, palliative; they focus on prompt diagnosis, supportive nutritional care and interventions for sequelae. The purpose of this article is to discuss the current treatment paradigm for BA and to assess the impact these strategies have on outcomes. As more children with BA survive into adulthood with their native liver, it is important to understand which factors predict good and poor outcomes.

National academy of clinical biochemistry laboratory medicine practice guidelines: follow-up testing for metabolic disease identified by expanded newborn screening using tandem mass spectrometry; executive summary

BACKGROUND

Almost all newborns in the US are screened at birth for multiple inborn errors of metabolism using tandem mass spectrometry. Screening tests are designed to be sufficiently sensitive so that cases are not missed. The NACB recognized a need for standard guidelines for laboratory confirmation of a positive newborn screen such that all babies would benefit from equal and optimal follow-up by confirmatory testing.

METHODS

A committee was formed to review available data pertaining to confirmatory testing. The committee evaluated previously published guidelines, published methodological and clinical studies, clinical case reports, and expert opinion to support optimal confirmatory testing. Grading was based on guidelines adopted from criteria derived from the US Preventive Services Task Force and on the strength of recommendations and the quality of the evidence. Three primary methods of analyte measurement were evaluated for confirmatory testing including measurement of amino acids, organic acids, and carnitine esters. The committee graded the evidence for diagnostic utility of each test for the screened conditions.

RESULTS

Ample data and experience were available to make strong recommendations for the practice of analyzing amino acids, organic acids, and acylcarnitines. Likewise, strong recommendations were made for the follow-up test menu for many disorders, particularly those with highest prevalence. Fewer data exist to determine the impact of newborn screening on patient outcomes in all but a few disorders. The guidelines also provide an assessment of developing technology that will fuel a refinement of current practice and ultimate expansion of the diseases detectable by tandem mass spectrometry.

CONCLUSIONS

Guidelines are provided for optimal follow-up testing for positive newborn screens using tandem mass spectrometry. The committee regards these tests as reliable and currently optimal for follow-up testing. .

Bile Acid sulfation: a pathway of bile acid elimination and detoxification

Sulfotransferase-2A1 catalyzes the formation of bile acid-sulfates (BA-sulfates). Sulfation of BAs increases their solubility, decreases their intestinal absorption, and enhances their fecal and urinary excretion. BA-sulfates are also less toxic than their unsulfated counterparts. Therefore, sulfation is an important detoxification pathway of BAs. Major species differences in BA sulfation exist. In humans, only a small proportion of BAs in bile and serum are sulfated, whereas more than 70% of BAs in urine are sulfated, indicating their efficient elimination in urine. The formation of BA-sulfates increases during cholestatic diseases. Therefore, sulfation may play an important role in maintaining BA homeostasis under pathologic conditions. Farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, and vitamin D receptor are potential nuclear receptors that may be involved in the regulation of BA sulfation. This review highlights current knowledge about the enzymes and transporters involved in the formation and elimination of BA-sulfates, the effect of sulfation on the pharmacologic and toxicologic properties of BAs, the role of BA sulfation in cholestatic diseases, and the regulation of BA sulfation.

Recent advances in biliary atresia: prospects for novel therapies

BACKGROUND

Biliary atresia (BA) is a progressive fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction before 2 months of age. Untreated BA is a uniformly fatal disease and even with our current therapies only 50% of children with BA will be transplant-free by 2 years of age. Despite descriptions of this disorder dating back to the 1800s our current therapies are palliative. They focus on prompt diagnosis, supportive nutritional care and interventions for sequelae.

OBJECTIVE

To present the literature supporting current treatment strategies and potential future therapies.

METHOD

Each of the aspects of care is described and the literature about nuances of care is provided.

CONCLUSION

Therapies will not improve outcomes until novel treatments are introduced, such as those suggested, which may intervene in the inflammatory or fibrotic steps of the disease process.

Neonatal jaundice: a critical review of the role and practice of bilirubin analysis

Neonatal jaundice is common, and usually harmless, because of physiological jaundice or breast-feeding. In some neonates unconjugated bilirubin concentration, coupled with other risk factors, is sufficient to allow free bilirubin to cross the blood-brain barrier and cause kernicterus. Another subgroup of infants is jaundiced because of elevated conjugated bilirubin; a marker for a number of pathological conditions. Bilirubin measurement must identify those infants at risk. Transcutaneous bilirubin measurement is increasingly used in healthy infants, especially before early discharge or at home, to assess the need for laboratory bilirubin measurement. Transcutaneous measurements are not covered by laboratory quality assessment schemes. Guidelines on management of neonatal jaundice utilize age in hours and other risk factors to define bilirubin action thresholds, which may be as low as 100 μmol/L for sick premature infants, whereas early discharged babies may only present after bilirubin concentrations are extremely high. Hence, there is a requirement for accurate total bilirubin measurement from <100 to >500 μmol/L, with sufficient precision to assess the rate of bilirubin change with time. Babies presenting with late jaundice always require conjugated bilirubin measurement. It is of concern that many total and direct bilirubin automated kit methods suffer from haemolysis interference, while use of in-house methods or modification of commercial methods has virtually disappeared. External quality assessment has a vital role in providing data on different methods' performance, including accuracy, precision and susceptibility to interference. Laboratories should consider whether their adult bilirubin methods are suitable for neonates.

Universal screening for biliary atresia using an infant stool color card in Taiwan

Biliary atresia is the most common cause of death from liver disease in children. Although the Kasai operation before 60 days of age can significantly improve prognosis, delay in referral and surgery remains a formidable problem worldwide because of difficulties in differentiating it from benign prolonged neonatal jaundice. We established a universal screening system using an infant stool color card to promote the early diagnosis and treatment of biliary atresia. After a pilot regional study in 2002-2003, a national stool color screening system was established by integrating the infant stool color card into the child health booklet given to every neonate in Taiwan since 2004. Within 24 hours of the discovery of an abnormal stool color, this event is reported to the registry center. The annual incidence of biliary atresia per 10,000 live births in 2004 and 2005 was 1.85 (40/216,419) and 1.70 (35/205,854), respectively. The sensitivity of detecting biliary atresia using stool cards before 60 days of age was 72.5% in 2004, which improved to 97.1% in 2005. The national rate of the Kasai operation before 60 days of age increased from 60% in 2004 to 74.3% in 2005. The jaundice-free rate (<2 mg/dL) at 3 months after the Kasai operation among infants with biliary atresia in 2004-2005 was 59.5% (44 of 74), significantly higher than the historical data of 37.0% in 1976-2000 before the stool card screening program (P = 0.002).

CONCLUSION

Universal screening using the stool color cards can enhance earlier referral, which may ultimately lead to timely performance of the Kasai operation and better postoperative outcome in infants with biliary atresia.