Neonatal Cholestasis

Liver Disorders Caused by Inborn Errors of Metabolism

Inborn errors of metabolism (IEMs) are a vast array of inherited/congenital disorders, affecting a wide variety of metabolic pathways and/or biochemical processes inside the cells. Although IEMs are usually rare, they can be represented as serious health problems. During the neonatal period, these inherited defects can give rise to almost all key signs of liver malfunction, including jaundice, coagulopathy, hepato- and splenomegaly, ascites, etc. Since the liver is a vital organ with multiple synthetic, metabolic, and excretory functions, IEM-related hepatic dysfunction could seriously be considered life-threatening. In this context, the identification of those hepatic manifestations and their associated characteristics may promote the differential diagnosis of IEMs immediately after birth, making therapeutic strategies more successful in preventing the occurrence of subsequent events. Among all possible liver defects caused by IEMs, cholestatic jaundice, hepatosplenomegaly, and liver failure have been shown to be manifested more frequently. Therefore, the current study aims to review substantial IEMs that mostly result in the aforementioned hepatic disorders, relying on clinical principles, especially through the first years of life. In this article, a group of uncommon hepatic manifestations linked to IEMs is also discussed in brief.

Biliary atresia and congenital disorders of the extrahepatic bile ducts

Biliary atresia (BA) and choledochal cysts are diseases of the intrahepatic and extrahepatic biliary tree. While their exact etiopathogeneses are not known, they should be treated promptly due to the potential for irreversible parenchymal liver disease. A diagnosis of BA may be easy or complicated, but should not be delayed. BA is always treated surgically, and performing the surgery before the age of 2 mo greatly increases its effectiveness and extends the time until the need for liver transplantation arises. While the more common types of choledochal cysts require surgical treatment, some can be treated with endoscopic retrograde cholangiopancreatography. Choledochal cysts may cause recurrent cholangitis and the potential for malignancy should not be ignored.

Comprehensive Analysis of Gut Microbiota and Fecal Bile Acid Profiles in Children With Biliary Atresia

Background

Biliary atresia (BA) is the most common cholestatic liver disease in neonates. Herein, we aimed at characterizing the gut microbiota and fecal bile acid profiles of BA patients, defining the correlations between them, and evaluating the relationship between the clinical pathogenesis and changes in the gut microbiota and bile acid profiles.

Methods

A total of 84 fecal samples from BA patients (n = 46) and matched healthy controls (HCs, n = 38) were subjected to sequencing by 16S rRNA gene amplification, and fecal bile acid were analyzed by targeted metabolomics.

Findings

Compared with the controls, a structural separation of the intestinal flora of BA patients was uncovered, which was accompanied by changes in the composition of fecal bile acids. In the BA group, Actinobacillus, Monoglobus, and Agathobacter were enriched in patients without cholangitis (p < 0.05). Selenomonadaceae and Megamonas were more abundant in patients without recurrent cholangitis episodes (p < 0.05), while Lachnospiraceae and Ruminococcaceae were enriched in patients with multiple recurrences of cholangitis (p < 0.05). Postoperative jaundice clearance was associated with Campylobacter and Rikenellaceae (p < 0.05), and tauroursodeoxycholic acid was associated with jaundice clearance (p < 0.001).

Conclusion

BA patients are characterized by different compositions of gut microbiota and bile acids, and their interaction is involved in the process of liver damage in BA, which may be closely related to the occurrence of postoperative cholangitis and jaundice clearance.

Management of severe hyperbilirubinemia in the cholestatic neonate: a review and an approach

A review of the literature demonstrates that severe total hyperbilirubinemia (total serum bilirubin ≥ 20 mg/dL [340 µmol/L]) in some cholestatic term (≥37 weeks) and late-preterm (≥34^0/7-36^6/7 weeks) gestation neonates poses a risk for bilirubin-induced brain damage. When the direct bilirubin fraction is <50% of the total serum bilirubin this risk is associated with the total serum bilirubin alone and treatment decisions should be based on the total serum bilirubin. On the other hand, there are limited data on the risk of bilirubin-induced brain damage in the neonate with severe total hyperbilirubinemia and a direct bilirubin fraction that is equal to or exceeds 50% of the total serum bilirubin. When this rare combination occurs, efforts to keep the indirect bilirubin fraction from reaching severe levels might, nevertheless, be prudent.

Etiology of neonatal cholestasis after emerging molecular diagnostics

BACKGROUND

In the pediatric group, most cholestatic patients had disease onset at 0-3 months of age, and more and more are found to have specific genetic defects after failing to obtain a definite diagnosis by routine evaluation. To investigate the etiological diagnosis for the newborns with cholestasis during the neonatal period after emerging molecular tests comprehensively.

METHODS

We conducted a retrospective study to evaluate clinical characteristics, etiologies and outcomes in infants with neonatal cholestasis after emerging molecular diagnostics from January 1st to December 31st, 2019 in Children's Hospital of Fudan University.

RESULTS

There were 160 cases of neonatal cholestasis with mean gestational age (GA) 32.6±4.8 weeks and birth weight (BW) 1,880±991 g, composing 3.4% of total neonatal admissions in 2019. Overall 97.5% (n=156) patients had a definite diagnosis, including 9 obtaining a genetic diagnosis after adding molecular test in routine evaluation, which made the diagnosis rate for cholestasis increased by 5.6%. The most common etiology of cholestasis in the neonatal period was parenteral nutrition-associated cholestasis (PNAC) 48.8% (n=78), followed by cardiovascular and circulatory disorders 18.1%, biliary anatomic obstruction 12.5%, infection 8.7% and genetic disorders 5.6%. PNAC and biliary anatomic obstruction were the most common etiology of cholestasis for preterm and term infants respectively. The mortality rate is 2.5% (n=4) and 91.9% (n=147) patients totally recovery or improve in follow-up.

CONCLUSIONS

The causes of cholestasis in neonates are complicated, molecular diagnostics can improve the etiological diagnosis for newborns with cholestasis. But still, quite amount of causes are remediable and transient during the neonatal period, gene test may help to rule out genetic causes and enhance confidence in judging prognosis.

Ursodeoxycholic Acid and SMOFlipid for Treating Parenteral Nutrition Associated Cholestasis in Infants

Background: Parenteral nutrition-associated cholestasis (PNAC) is frequently seen in preterm infants receiving total parenteral nutrition (TPN) for a long duration. The pathogenesis of PNAC is believed to be multifactorial; however, phytosterols are hepatotoxic, resulting in cholestasis. A novel lipid emulsion consisting of a mixture of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOFlipid) with a low level of phytosterols has been shown to improve cholestasis. Moreover, ursodeoxycholic acid (UDCA) has improved bile flow and normalized liver function tests. This study aimed to determine the effect of UDCA and SMOFlipid in preventing and treating PNAC in infants.

Methods: We conducted a retrospective cohort study that included all infants who received TPN for at least five days between January 2010 and December 2018, who also received UDCA for the treatment of cholestasis, and infants who developed cholestasis but were not treated with UDCA. In addition, any infants who received SMOFlipid for parenteral nutrition during the same period were included. We recorded multiple variables, including neonatal demographic data, major medical diagnosis, liver function, medications, and maternal variables.

Results: A total of 58 infants with cholestasis who received UDCA for treatment were identified. The infants were divided into two groups, Group 1 infants had gestational age (GA) of ≤32 weeks, and Group 2 had GA of >32 weeks. We found that combining SMOFlipid with UDCA resulted in a significant reduction in cholestasis duration in both groups. Infants in Group 1 who received SMOFlipid had cholestasis for a mean of 67 ± 57 days, and those who did not receive SMOFlipid had cholestasis for a mean of 145 ± 102 days (p=0.04). Infants in Group 2 who received SMOFlipid had cholestasis for a mean of 38.2 ± 28 days, and those who did not receive SMOFlipid had cholestasis for a mean of 117 ± 119 days (p=0.02).

Conclusions: According to our results, the use of UDCA and SMOFlipid reduced the duration of parenteral nutrition-associated with cholestasis in very low birth weight infants.

A Novel Intronic Mutation Reduces HAX1 Level and is Associated With Severe Congenital Neutropenia

Severe congenital neutropenia (SCN) is a rare disease. Autosomal recessive forms of SCN are more frequent in countries where consanguineous marriages are common. In this report, we describe a 54-day-old female with neutropenia who presented with ecthyma gangrenosum. Clinical exome sequencing was used to identify the mutation. HAX1 messenger RNA and isoforms were examined by real-time quantitative and conventional polymerase chain reaction. Bone marrow aspiration was stained by hematoxylin and eosin. Granulocytes were tested for apoptosis upon H2O2 exposure. T-cell proliferation was tested by flow cytometry. Clinical exome sequencing revealed a novel homozygous acceptor splice site mutation in intron 3 of HAX1 (c.505-1G>C), which reduced both isoforms A and B of HAX1 messenger RNA. The Western blot studies showed a complete absence of HAX1 protein. The purified neutrophils from the patient showed increased apoptosis upon H2O2 exposure, whereas T-cell proliferative responses to various stimuli were intact. The patient was treated with combined antibiotics, filgrastim, and placed on antibiotics prophylaxis. To the best of our knowledge, our data provide the first experimental evidence for HAX1 deficiency because of a splice site mutation. Although 3 other splice site variants have been deposited in databases, functional studies were missing. This novel variant of HAX1 may explain the SCN and secondary infections in our patients.

Newer variants of progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of disorders characterized by defects in bile secretion and presentation with intrahepatic cholestasis in infancy or childhood. The most common types include PFIC 1 (deficiency of FIC1 protein, ATP8B1 gene mutation), PFIC 2 (bile salt export pump deficiency, ABCB11 gene mutation), and PFIC 3 (multidrug resistance protein-3 deficiency, ABCB4 gene mutation). Mutational analysis of subjects with normal gamma-glutamyl transferase cholestasis of unknown etiology has led to the identification of newer variants of PFIC, known as PFIC 4, 5, and MYO5B related (sometimes known as PFIC 6). PFIC 4 is caused by the loss of function of tight junction protein 2 (TJP2) and PFIC 5 is due to NR1H4 mutation causing Farnesoid X receptor deficiency. MYO5B gene mutation causes microvillous inclusion disease (MVID) and is also associated with isolated cholestasis. Children with TJP2 related cholestasis (PFIC-4) have a variable spectrum of presentation. Some have a self-limiting disease, while others have progressive liver disease with an increased risk of hepatocellular carcinoma. Hence, frequent surveillance for hepatocellular carcinoma is recommended from infancy. PFIC-5 patients usually have rapidly progressive liver disease with early onset coagulopathy, high alpha-fetoprotein and ultimately require a liver transplant. Subjects with MYO5 B-related disease can present with isolated cholestasis or cholestasis with intractable diarrhea (MVID). These children are at risk of worsening cholestasis post intestinal transplant (IT) for MVID, hence combined intestinal and liver transplant or IT with biliary diversion is preferred. Immunohistochemistry can differentiate most of the variants of PFIC but confirmation requires genetic analysis.

A Two-Year Clinical Description of a Patient with a Rare Type of Low-GGT Cholestasis Caused by a Novel Variant of USP53

Here, we report a novel truncating mutation in the ubiquitin-specific peptidase gene (USP53) causing low-γ-GT (GGT) cholestasis. Genetic testing was carried out, including clinical exome sequencing for the proband and Sanger sequencing for the proband and his parents. The proband harbored a novel c.1017_1057del (p.(Cys339TrpfsTer7)) mutation in the ubiquitin carboxyl-terminal hydrolase (UCH) domain of USP53; we describe the clinical and laboratory features of the patient with a rare type of low-GGT cholestasis caused by this variant. The clinical presentation was found to be similar to that of phenotypes described in previous studies. However, there was an unusual presence of liver hemangiomas observed in our patient. Thus, our report reinforces the link between USP53 mutations and cholestasis. With this report, we confirm USP53 as the gene for low-GGT cholestasis and describe liver hemangiomas as a possible additional symptom of the phenotype spectrum. The inclusion of USP53 in the OMIM database and liver gene panels can further increase the effectiveness of molecular genetic studies.

Association of Gut Microbiota and Metabolites With Disease Progression in Children With Biliary Atresia

Background and Aims

Biliary atresia is the most common cause of liver disease and liver transplantation in children. The accumulation of bile acids in hepatocytes and the stimulation of the intestinal microbiome can aggravate the disease progression. This study investigated changes in the composition of the gut microbiota and its metabolites in biliary atresia and the possible effects of these changes on disease progression.

Methods

Stool samples of biliary atresia at different disease stages and matched control individuals were collected (early stage: 16 patients, 16 controls; later stage: 16 patients, 10 controls). Metagenomic sequencing was performed to evaluate the gut microbiota structure. Untargeted metabolomics was performed to detect and analyze the metabolites and bile acid composition.

Results

A disturbed gut microbiota structure occurred in the early and later stages of biliary atresia. Klebsiella, Streptococcus, Veillonella, and Enterococcus have always been dominant. The abundance of V. atypica displayed significant changes between the early and later stages of biliary atresia. Combined with clinical indicators, Spearman’s analysis showed that Klebsiella and Veillonella atypica strongly correlated with liver enzymes. Enterococcus faecium had an enormously positive relationship with lithocholic acid derivatives. Metabolites involved in tryptophan metabolism were changed in the patients with biliary atresia, which had a significant association with stool V. atypica and blood total bilirubin (p < 0.05).

Conclusions

The liver damage of biliary atresia was directly or indirectly exacerbated by the interaction of enriched Klebsiella (K. pneumoniae), Veillonella (V. atypica), and Enterococcus (E. faecium) with dysmetabolism of tryptophan and bile acid.

Efficacy of Zhuyu Pill Intervention in a Cholestasis Rat Model: Mutual Effects on Fecal Metabolism and Microbial Diversity

Cholestasis is a clinical condition resulting from impaired bile flow. Currently, patients with cholestasis face several barriers in seeking diagnosis and treatment. Zhuyu Pill (ZYP) is an ancient classic formula of the Coptis-Evodia herb couples (CEHC), and has been used for cholestasis treatment in the clinic, however, its underlying biological activity in cholestasis remain to be clarified. In this study, an α-naphthyl-isothiocyanate (ANIT, 50 mg/kg)-induced rat model of cholestasis was treated with ZYP. Serum biochemical indices and histopathological evaluation was performed, together with the metabolomics analyses of feces and 16S rDNA sequencing of the fecal microbiota. We evaluated the anti-cholestatic activity of ZYP and investigated the mechanisms underlying its correlation with fecal microbiota and fecal metabolite regulation. The relationships between biochemical indices and changes in gene expression associated with liver injury, levels fecal metabolites, and composition of fecal microbiota were analyzed. The results showed that both high (1.2 g/kg) and low (0.6 g/kg) doses of ZYP could effectively improve biochemical parameters in the blood of cholestasis-induced rat models; the intervention effect of high dose ZYP was superior to that that of lower dose ZYP. Based on a metabolomics test of fecal samples, significantly altered metabolites in the ANIT and ZYP treatment group were identified. In total, 734 metabolites were differentially expressed, and whose biological functions were mainly associated with amino acid metabolism, steroid hormone biosynthesis, and bile secretion. In addition, sequencing of the 16S rDNA unit in fecal samples revealed that the ZYP could improve the fecal microbiota dysbiosis that ANIT had induced. Therefore, we conclude that ANIT altering of blood biochemical and metabolic profiles and of fecal microbiota could effectively be alleviated with ZYP treatment. This study contributes to the “TCM wisdom” applied in clinical diagnosis and treatment of cholestasis.

Neonatal jaundice, attention deficit hyperactivity disorder and familial effects: A Swedish register study with sibling analysis

AIM

Neonatal jaundice is associated with higher risk of attention deficit hyperactivity disorder (ADHD), but it is unclear if the association is influenced by genetic and other familial factors. In this large population-based study, we investigated the association between neonatal jaundice and ADHD while adjusting for familial factors.

METHODS

We linked several Swedish registers to identify all singleton births without congenital malformations between 1992 and 2000 (n = 814 420, including 384 290 full siblings) and followed them up until 2009. We calculated hazard ratios (HRs) for the association between neonatal jaundice and ADHD, adjusting for pregnancy, delivery and neonatal characteristics including prematurity, and parental age and education. We repeated the analyses among siblings to adjust for shared familial factors.

RESULTS

At a population level, children treated for neonatal jaundice had an increased risk of ADHD (adjusted HR (aHR): 1.13, 95% CI: 1.05-1.22). In the sibling comparisons, there was no clear association between neonatal jaundice and ADHD (aHR: 1.03, 95% CI: 0.82-1.29).

CONCLUSION

We found no evidence of an independent association between neonatal jaundice and ADHD within siblings in this large population-based study, suggesting that the association is probably influenced by shared familial factors, such as parental genetic and/or lifestyle effects.

Cholestatic jaundice in neonates: How common is biliary atresia? Experience at an Australian tertiary centre

AIM

To (i) review the aetiologies of neonatal cholestasis among term and preterm neonates at a single tertiary centre in Australia; (ii) identify clinical variables associated with biliary atresia (BA) and non-BA aetiology of neonatal cholestasis; (iii) investigate the utility of hepatobiliary scintigraphy in predicting BA among term and preterm neonates.

METHODS

A retrospective cohort study of neonates born and investigated for cholestasis at two co-located neonatal and children facilities from January 2013 to December 2017.

RESULTS

Of the 139 neonates with cholestasis, BA and intestinal-failure-associated liver-disease was the most common cause of neonatal cholestasis in term (18%) and preterm (66%) cohorts, respectively. Incidence of BA was higher in term (1:6) than preterm (1:50) neonates (OR 10.29; 95% CI 2.06-49.97, P = 0.0024). Higher birthweight, acholic stool, absent or abnormal gallbladder on ultrasound was significantly associated with BA while gestational age ≤32 weeks, total parenteral nutrition ≥14 days and low albumin were associated with non-BA aetiology of cholestasis. In diagnosing BA, non-draining hepatobiliary scintigraphy demonstrated a lower specificity (73% vs. 90%) and lower positive predictive value (25% vs. 78%) in preterm compared to term neonates.

CONCLUSION

Aetiology of cholestasis among preterm neonates differs from those in term neonates and currently existing diagnostic algorithm for neonatal cholestasis may need to be modified for preterm cohort, taking into account the prevalence for each aetiology, potential predictors and cost-efficiency.

Incidence of Complications Associated with Parenteral Nutrition in Preterm Infants < 32 Weeks with a Mixed Oil Lipid Emulsion vs a Soybean Oil Lipid Emulsion in a Level IV Neonatal Intensive Care Unit

BACKGROUND

Parenteral nutrition (PN) is crucial for the improvement of long-term outcomes in very low birth weight (VLBW) neonates. Lipid injectable emulsions are a key component of PN, as they contain essential fatty acids and provide energy critical for brain growth. Prolonged administration increases risk of intestinal failure-associated liver disease, including cholestasis, and other complications.

METHODS

This is a retrospective, quasi-experimental cohort study of 215 VLBW neonates. The primary outcome was a change in direct bilirubin concentration. Secondary outcomes included change in total bilirubin concentration and incidences of cholestasis and other disease states associated with PN and prematurity. Cholestasis was defined as direct bilirubin ≥ 1.0 mg/dL with total bilirubin < 5.0 mg/dL or direct bilirubin > 20% of total bilirubin with total bilirubin > 5.0 mg/dL.

RESULTS

Change in direct bilirubin concentration was not different between groups. Incidence of cholestasis was not different between groups per charted diagnosis or per study definition. Non-stage-0 retinopathy of prematurity, bronchopulmonary dysplasia, sepsis, and necrotizing enterocolitis were all lower in the mixed oil lipid emulsion group, which remained significant after adjustment for differences in gestational age, birth weight, and PN duration.

CONCLUSIONS

Although mixed oil lipid emulsion was not found to be associated with a lower risk of cholestasis, it may decrease risks of other disease states associated with PN therapy.

Recent developments in diagnostics and treatment of neonatal cholestasis

Neonatal cholestasis is characterized by conjugated hyperbilirubinemia in the newborn and young infant and is a sign common to over 100 hepatobiliary and/or metabolic disorders. A timely evaluation for its etiology is critical in order to quickly identify treatable causes such as biliary atresia, many of which benefit from early therapy. An expanding group of molecularly defined disorders involving bile formation, canalicular transporters, tight junction proteins and inborn errors of metabolism are being continuously discovered because of advances in genetic testing and bioinformatics. The advent of next generation sequencing has transformed our ability to test for multiple genes and whole exome or whole genome sequencing within days to weeks, enabling rapid and affordable molecular diagnosis for disorders that cannot be directly diagnosed from standard blood tests or liver biopsy. Thus, our diagnostic algorithms for neonatal cholestasis are undergoing transformation, moving genetic sequencing to earlier in the evaluation pathway once biliary atresia, "red flag" disorders and treatable disorders are excluded. Current therapies focus on promoting bile flow, reducing pruritus, ensuring optimal nutrition, and monitoring for complications, without addressing the underlying cause of cholestasis in most instances. Our improved understanding of bile formation and the enterohepatic circulation of bile acids has led to emerging therapies for cholestasis which require appropriate pediatric clinical trials. Despite these advances, the cause and optimal therapy for biliary atresia remain elusive. The goals of this review are to outline the etiologies, diagnostic pathways and current and emerging management strategies for neonatal cholestasis.

Low-GGT intrahepatic cholestasis associated with biallelic USP53 variants: Clinical, histological and ultrastructural characterization

BACKGROUND & AIMS

In about 20% of children with cholestasis and normal or low serum gamma-glutamyltransferase (GGT) activity, no aetiology is identified. We sought new genes implicated in paediatric hepatobiliary disease.

METHODS

We conducted whole-exome sequencing in 69 children evaluated at our centre from 2011 to 2018 who had low-GGT cholestasis and in whom homozygous/compound heterozygous predictedly pathogenic variants (PPVs) in ATP8B1, ABCB11, NR1H4, MYO5B or TJP2 were not found. Clinical records and findings on light microscopy and transmission electron microscopy of liver biopsy materials were reviewed.

RESULTS

In seven patients from seven unrelated families, biallelic PPVs (10 in total) were found in USP53, recently associated with intrahepatic cholestasis. Seven variants were classified as pathogenic: one canonical splicing, c.569 + 2T > C, and six nonsense or frameshifting: c.169C > T (p.Arg57Ter), c.581delA (p.Arg195GlufsTer38), c.831_832insAG (p.Val279GlufsTer16), c.1012C > T (p.Arg338Ter), c.1426C > T (p.Arg476Ter) and c.1558C > T (p.Arg520Ter). Three were likely pathogenic: c.297G > T (p.Arg99Ser), c.395A > G (p.His132Arg) and c.878G > T (p.Gly293Val). In all patients, jaundice began at age <7 months. Cholestasis was transient, with documented resolution of hyperbilirubinaemia in all (oldest patient now aged 5 years) except one, who was lost to follow-up. Light microscopy identified intralobular cholestasis, giant-cell change of hepatocytes and perisinusoidal-perihepatocytic and portal-tract fibrosis. Ultrastructural study revealed elongated hepatocyte-hepatocyte tight junctions. One patient was deaf.

CONCLUSION

USP53 interacts with the tight junction constituent TJP2. TJP2 mutation can cause low-GGT intrahepatic cholestasis, with elongated hepatocyte-hepatocyte tight junctions, as well as deafness. Our findings extend a preliminary report of USP53 disease and indicate that USP53 mutation may generate a partial phenocopy of TJP2 disease.

Neonatal cholestasis, hyperferritinemia, hypoglycemia and deafness: a diagnostic challenge

Neonatal conjugated hyperbilirubinemia is a diagnostic challenge. A full term, small for gestational age boy presented with cholestasis, hypoglycemia, hyperferritinemia and severe bilateral deafness. Diagnostic work-up revealed two hereditary diseases: alpha-1-antitrypsin deficiency (PI*ZZ genotype) and autosomal recessive deafness type 3 (compound heterozygous MYO15A gene mutation). In addition, we found late hypoglycemia on full enteral feeding which complicated this case. Hyperferritinemia is an uncommon finding in newborn cholestasis without liver failure.

A practical approach to the pathology of neonatal cholestatic liver disease

Navigating the complexities of interpreting a liver biopsy performed on a neonate with conjugated/direct hyperbilirubinemia can be an arduous task given these biopsies are infrequently encountered. The list of entities is long and yet there are only a few histologic patterns of liver injury. The first step for the pathologist is to determine the histologic pattern, which will guide further inquiry into the useful clinical information to have while evaluating the biopsy. Ultimately, the goal is to identify those conditions that will benefit from early intervention. We begin with a review of biliary development to help understand what findings may be physiologic versus pathologic, particularly in premature infants. Then we review eight cases that cover the three most common histologic patterns of injury in patients with neonatal cholestasis: biliary obstructive, neonatal hepatitis, and paucity of intrahepatic bile ducts. The entities that serve as prototypes for these histologic patterns are covered, including biliary atresia, idiopathic neonatal hepatitis, and Alagille syndrome, along with rarer entities that have histologic overlap. The cases with accompanying tables and algorithms are intended to help place the histologic findings in the context of the overall clinical work-up, including genetic testing.

Neonatal cholestasis: emerging molecular diagnostics and potential novel therapeutics

Neonatal cholestasis is a group of rare disorders of impaired bile flow characterized by conjugated hyperbilirubinaemia in the newborn and young infant. Neonatal cholestasis is never physiological but rather is a sign of hepatobiliary and/or metabolic disorders, some of which might be fatal if not identified and treated rapidly. A step-wise timely evaluation is essential to quickly identify those causes amenable to treatment and to offer accurate prognosis. The aetiology of neonatal cholestasis now includes an expanding group of molecularly defined entities with overlapping clinical presentations. In the past two decades, our understanding of the molecular basis of many of these cholestatic diseases has improved markedly. Simultaneous next-generation sequencing for multiple genes and whole-exome or whole-genome sequencing now enable rapid and affordable molecular diagnosis for many of these disorders that cannot be directly diagnosed from standard blood tests or liver biopsy. Unfortunately, despite these advances, the aetiology and optimal therapeutic approach of the most common of these disorders, biliary atresia, remain unclear. The goals of this Review are to discuss the aetiologies, algorithms for evaluation and current and emerging therapeutic options for neonatal cholestasis.

A case report of a challenging diagnosis of biliary atresia in a patient receiving total parenteral nutrition

Background

Total parenteral nutrition (TPN) and biliary atresia (BA) are common causes of cholestasis in infancy. The diagnosis of BA is time sensitive due to an inverse correlation between age at intervention (hepatic portoenterostomy - HPE) and survival without liver transplantation. Clinical, laboratory, and histologic features of BA and parenteral nutrition associated cholestasis (PNAC) are similar, creating a diagnostic dilemma for cholestatic infants on parenteral nutrition. There is limited published information about the natural history of PNAC including time to resolution, or diagnostic tests that distinguish BA from other etiologies of cholestasis.

Case presentation

We present a case of a child diagnosed with BA whose cholestasis began while receiving TPN. His clinical course was notable for transient resolution of his cholestasis after stopping parenteral nutrition and ultimate intraoperative diagnosis.

Conclusions

Clinicians who care for patients who frequently receive TPN should be aware that clinical, laboratory, imaging, and biopsy findings can be similar between BA and PNAC.

Vitamin K deficiency bleeding in an apparently healthy newborn infant: the compelling need for evidence-based recommendation

BACKGROUND

Vitamin K is a key point for guarantee normal blood clotting and its level in newborns is commonly low, so a supplementation after delivery is mandatory. Vitamin K prophylaxis in newborns is still an open field of debate: many types of protocol have been proposed in different years and Countries, and sometimes with great variability inside the same Nation (for instance, in Italy a national consensus is not available, so different protocols are employed). Recommendations include different protocols for healthy newborns born at term, but the unpreventable presence of bleeding favouring factors (i.e. blood vessels malformations) or limiting intestinal absorption of liposoluble vitamins (i.e. cholestasis), which could be unrecognized or subclinical in the perinatal period, rises some concerning about the most precautionary route of administration and the timing of further doses after the first one given at birth. The purpose of this report is to underline the most recent evidences available in literature and to arise a debate about this topic, in order to stimulate the production of evidence-based guidelines concerning the prophylaxis with vitamin K1 in newborn infants, considering that many bleeding risk factors are not recognizable at birth.

CASE PRESENTATION

We are hereby presenting an emblematic case concerning the risk of intracranial bleeding in an apparently healthy newborn: the described infant did not show any pathological elements in pregnancy history or perinatal life which suggest a possible increased risk of bleeding and the needing of a particular approach in the administration of vitamin K1, but at the end of the first week of life presented an intracranial bleeding with neurological symptoms that required treatment for vitamin K deficiency.

CONCLUSIONS

Univocal recommendations about vitamin K prophylaxis are not available and the contrast between oral and intramuscular routes persists unsolved. The difficulty to certainly identify an infant eligible for oral administration of vitamin K1 at birth suggests that the intramuscular route should be preferred. How to prosecute the supplementation in the first months of life is still an open topic of debate.