Update on the etiologies and management of neonatal cholestasis

Biliary atresia in children (analytical literature review and review of own observation)

OBJECTIVE

Aim: to review information resources and analysis of the own experience on this problem for the provision of modern knowledge in the pathogenesis of the pathology, the latest diagnostic and treatment technologies, with consideration of the need to adhere to a single strategy in the management of patients with BA.

PATIENTS AND METHODS

Materials and Methods: The analysis of the data regarding the results of existing studies evaluating the clinical benefit and safety of diagnostic and treatment methods in Biliary atresia.

CONCLUSION

Conclusions: BA is the leading cause of neonatal cholestasis development. Early diagnostics of BA, based on the complex evaluation of clinical-laboratory, instrumental and morphological signs of the pathology, has a significant meaning. Surgical correction during the first 2 months of life - the Kasai procedure, as well as dynamic post-surgery follow-up significantly prolong the life of children and allow postponing liver transplantation. The highest patient survival both at the first stage of treatment - conduction of the Kasai procedure and the stage of liver transplantation may be achieved by joined work of surgeons and pediatricians, which allows considering the whole row of possible problems.

Pediatric Cholestasis: Epidemiology, Genetics, Diagnosis, and Current Management

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Gut Microbiota Dysbiosis Is Associated with Altered Bile Acid Metabolism in Infantile Cholestasis

The co-occurrence of gut microbiota dysbiosis and bile acid (BA) metabolism alteration has been reported in several human liver diseases. However, the gut microbiota dysbiosis in infantile cholestatic jaundice (CJ) and the linkage between gut bacterial changes and alterations of BA metabolism have not been determined. To address this question, we performed 16S rRNA gene sequencing to determine the alterations in the gut microbiota of infants with CJ, and assessed their association with the fecal levels of primary and secondary BAs. Our data reveal that CJ infants show marked declines in the fecal levels of primary BAs and most secondary BAs. A decreased ratio of cholic acid (CA)/chenodeoxycholic acid (CDCA) in infants with CJ indicated a shift in BA synthesis from the primary pathway to the alternative BA synthesis pathway. The bacterial taxa enriched in infants with CJ corresponded to the genera Clostridium, Gemella, Streptococcus, and Veillonella and the family Enterobacteriaceae and were negatively correlated with the fecal BA level and the CDCA/CA ratio but positively correlated with the serological indexes of impaired liver function. An increased ratio of deoxycholic acid (DCA)/CA was observed in a proportion of infants with CJ. The bacteria depleted in infants with CJ, including Bifidobacterium and Faecalibacterium prausnitzii, were positively and negatively correlated with the fecal levels of BAs and the serological markers of impaired liver function, respectively. In conclusion, the reduced concentration of BAs in the gut of infants with CJ is correlated with gut microbiota dysbiosis. The altered gut microbiota of infants with CJ likely upregulates the conversion from primary to secondary BAs.IMPORTANCE Liver health, fecal bile acid (BA) concentrations, and gut microbiota composition are closely connected. BAs and the microbiome influence each other in the gut, where bacteria modify the BA profile, while intestinal BAs regulate the growth of commensal bacteria, maintain the barrier integrity, and modulate the immune system. Previous studies have found that the co-occurrence of gut microbiota dysbiosis and BA metabolism alteration is present in many human liver diseases. Our study is the first to assess the gut microbiota composition in infantile cholestatic jaundice (CJ) and elucidate the linkage between gut bacterial changes and alterations of BA metabolism. We observed reduced levels of primary BAs and most secondary BAs in infants with CJ. The reduced concentration of fecal BAs in infantile CJ was associated with the overgrowth of gut bacteria with a pathogenic potential and the depletion of those with a potential benefit. The altered gut microbiota of infants with CJ likely upregulates the conversion from primary to secondary BAs. Our study provides a new perspective on potential targets for gut microbiota intervention directed at the management of infantile CJ.

Determining Bile Duct Density in the Mouse Liver

Mouse is broadly used as a model organism to study biliary diseases. To evaluate the development and function of the biliary system, various techniques are used, including serum chemistry, histological analysis, and immunostaining for specific markers. Although these techniques can provide important information about the biliary system, they often do not present a full picture of bile duct (BD) developmental defects across the whole liver. This is in part due to the robust ability of the mouse liver to drain the bile even in animals with significant impairment in biliary development. Here we present a simple method to calculate the average number of BDs associated with each portal vein (PV) in sections covering all lobes of mutant/transgenic mice. In this method, livers are mounted and sectioned in a stereotypic manner to facilitate comparison among various genotypes and experimental conditions. BDs are identified via light microscopy of cytokeratin-stained cholangiocytes, and then counted and divided by the total number of PVs present in liver section. As an example, we show how this method can clearly distinguish between wild-type mice and a mouse model of Alagille syndrome. The method presented here cannot substitute for techniques that visualize the three-dimensional structure of the biliary tree. However, it offers an easy and direct way to quantitatively assess BD development and the degree of ductular reaction formation in mice.

Pathophysiology, prevention, treatment, and outcomes of intestinal failure-associated liver disease

BACKGROUND

Intestinal failure-associated liver disease (IFALD) remains a serious problem in the treatment of infants with nutritional problems and short bowel syndrome.

METHODS

A review of the recent literature from 2010 to 2016, concentrating on articles related to the pathophysiology of IFALD and to outcomes of novel nutritional and pharmacological therapies for neonatal cholestasis in the post-surgical neonate.

RESULTS

The pathophysiology of IFALD relates to an increase sensitivity of the neonatal liver to cholestasis in the non-fed state; prolonged cholestasis almost inevitably results in liver damage which will progress from fibrosis to cirrhosis. Clinically discerned risk factors include premature birth, inflammation, sepsis, disruption of the enterohepatic circulation by creation of a proximal stoma, and the duration and type of parenteral nutritional support. Within the hepatocyte, the regulatory enzyme farsanoid receptor X (FXR) appears to play a pivotal role in the development of cholestasis. Recent studies have shown that its activity is suppressed by sepsis, and by plant phytosterols found in soy-based lipid preparations. This paradigm is reflected in the emerging consensus for the care of post-surgical neonates, which is based around a multi-disciplinary team approach. Using an algorithm-driven approach, an appropriate balance between caloric support and prevention of IFALD can be achieved.

CONCLUSIONS

Further prospective studies are required to further refine the optimal sequence of use of these therapies and the long-term effects on neurological development and hepatic function. However, with optimal care, the number of IF patients progressing to end-stage liver disease because of IFALD should be very low.

When babies turn yellow

Neonatal jaundice is a common condition seen in the primary care setting. Most afflicted babies have physiological jaundice and their prognosis is good. However, others have pathological jaundice, which must be detected early. High levels of serum bilirubin can also result in bilirubin encephalopathy. This article describes consultation tasks in the primary care setting with the aim of providing a guide for the safe management of neonatal jaundice. They include clinical assessment of the baby's well-being; looking out for features that suggest pathological jaundice; assessment for the presence of high-risk features; utilising appropriate laboratory tests for monitoring; assessing the degree of jaundice to decide if the child can be safely followed up in primary care; and providing advice on primary prevention measures and allaying parental concerns. The importance of stool colour examination and its role in early detection of cholestatic jaundice is emphasised.

[Clinical features of different clinical forms of childhood congenital hepatic fibrosis]

OBJECTIVE

To compare the clinical features of children with different clinical forms of congenital hepatic fibrosis (CHF), and provides a description of the characteristics of childhood CHF.

METHODS

Sixty children with CHF between January 2002 and June 2015 were enrolled, including 26 children with portal hypertensive CHF (PH CHF), 3 children with cholangitic CHF, 30 children with combined portal hypertensive and cholangitic CHF (mixed CHF), and 1 child with latent forms of CHF. The medical data of 26 children with PH CHF and 30 children with mixed CHF, including gender, age, clinical manifestations, physical signs, laboratory tests and imaging characteristics, were retrospectively studied.

RESULTS

Fever, jaundice and hepatomegaly were more frequently noted in children with mixed CHF than in those with PH CHF (P<0.05). Splenomegaly and liver cirrhosis occurred more often in children with CHF, but there was no significant difference in the incidences of splenomegaly and liver cirrhosis between the children with PH CHF and mixed CHF. The plasma prothrombin activity, white blood cell counts, platelet counts, mean platelet volume, serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, γ-glutamyl transferase, leucine aminopeptidase, and total bile acids in children with mixed CHF were higher than in those with PH CHF (P<0.05). The decreased international normalized ratio and lower serum albumin levels were more frequently observed in children with mixed CHF than in those with PH CHF (P<0.05).

CONCLUSIONS

PH and mixed CHF are common forms in childhood CHF. The children with the two forms of PH usually manifest portal hypertension such as cirrhosis and hepatosplenomegaly. The liver damage may be common in children with mixed CHF.

Morphometric assessment of liver fibrosis may enhance early diagnosis of biliary atresia

BACKGROUND

Neonatal cholestasis syndrome is considered as a major challenge in pediatric practice. This study was undertaken to investigate the value of morphometric assessment of hepatic fibrosis in early diagnosis of biliary atresia.

METHODS

We studied liver biopsy specimens from 53 patients with neonatal cholestasis. The patients were assigned to two groups: group 1 (25 patients with biliary atresia) and group 2 (28 patients with non-obstructive cholestasis). Morphometric assessment of fibrosis was performed for all biopsies; in addition, another twelve histological parameters were estimated and scored on a scale of 0 to 4. Biopsies of infants aged 60 days or younger were characterized and analyzed separately.

RESULTS

Morphometric value of fibrosis was significantly higher in group 1 than in group 2 (16.8 ± 8.4% vs. 5.9 ± 2.3%, respectively; P<0.001). By multiple regression analysis, bile ductular plugs, morphometric assessment of fibrosis, rosetting, portal tract inflammation and pattern of cholestasis were found to be significant in discriminating the two groups. In infants aged 60 days or younger, a cutoff value for morphometric assessment of fibrosis of 7.5% was the discriminating point between the two groups with a sensitivity of 80% and a specificity of 84%.

CONCLUSION

Morphometric assessment of hepatic fibrosis could enhance the value of liver biopsy in early diagnosis of biliary atresia.

Underlying etiologies of prolonged icterus in neonates

The purpose of this study was to determine underlying causes of prolonged neonatal icterus. Icterus or jaundice is an important common problem in neonatology. When this condition persists beyond 14 days, it is called prolonged or protracted neonatal icterus. Determining underlying causes of this problem is a pivotal step for management, because a delay in treatment may lead to serious complications or even death. In a prospective study, newborns with diagnosis of prolonged icterus were evaluated during a six-month period in Tabriz Children Teaching Hospital. Data regarding the past medical history, physical examination and appropriate laboratory and paraclinical investigations were gathered and accordingly, the underlying cause of jaundice was documented. One hundred newborns, 67 males and 33 females with a mean age of 21.5 +/- 4.5 days were enrolled. Breastfeeding, urinary tract infection, glucose 6-phosphate dehydrogenase deficiency and hypothyroidism were found as the main underlying causes in 75, 7, 7 and 4% of the cases. The exact etiology was unknown in 4% of newborns. ABO incompatibility, sepsis and Down syndrome were underlying etiologies in remaining three patients. Present study showed that the underlying causes of prolonged neonatal jaundice could be determined in majority of cases and breastfeeding is the most common one in this regard.

Demographic and nutritional factors associated with prolonged cholestatic jaundice in the premature infant

OBJECTIVE

The primary aim of this study was to determine if an association exists between amino-acid levels and development of cholestasis. The secondary aim of our amino-acid dose comparison trial was to identify factors associated with the development of prolonged cholestatic jaundice.

STUDY DESIGN

We compared demographic characteristics and amino-acid levels in neonates who developed cholestasis with those who did not. Parenteral-associated cholestatic liver disease was defined as a direct serum bilirubin above 5 mg per 100 ml any time during the first 28 days after birth in neonates with no history of biliary atresia or viral hepatitis. We obtained filter paper blood spots for amino acid and acylcarnitine measurements on the day of randomization and days 7 and 28 of age to identify a profile of values that could be used to identify neonates with evidence of abnormal liver function.

RESULT

We enrolled 122 neonates in our study; 13 (10.7%) developed cholestasis. Neonates who developed cholestasis were more immature, had lower birth weight, were exposed to parenteral nutrition for a longer period, had a higher cumulative dose of amino acids, were less often on enteral nutrition by day 7 of age, more often had a patent ductus arteriosus and severe intraventricular hemorrhage and were more commonly treated with steroids by 28 days of age. Amino acid and acylcarnitine values were not different for the two groups on the day of randomization. On day 7 (parenteral phase of nutrition), blood urea nitrogen, citrulline, histidine, methionine and succinyl carnitine were higher, and serine, glutamate and thyroxine levels were lower in the neonates who developed cholestasis than in who did not.

CONCLUSION

Cholestasis remains an important complication of parenteral nutrition, and several clinical and biochemical factors may be helpful in identifying high-risk patients.

Early onset conjugated hyperbilirubinemia in newborn infants

OBJECTIVES

To determine the causes and related outcomes of early onset conjugated hyperbilirubinemia in a group of newborn infants and to determine the incidence of sepsis in these neonates.

METHODS

The charts of 42 babies with conjugated hyperbilirubinemia were retrospectively reviewed.

RESULTS

The mean gestational age was 37 weeks and the mean postnatal age at presentation was 10 days. Culture-proven sepsis was identified in 15 babies (35.7% of total). Gram-negative bacteria were isolated in 10 cases and E. coli was the most common of these agents (7 cases). Perinatal hypoxia-ischemia was the second most frequent etiology (7 patients; 16.7% of total). The other diagnoses were blood group incompatibility (n=5), Down syndrome (n=3), cholestasis associated with parenteral nutrition (n=3), neonatal hepatitis (n=2), metabolic liver disease (n=1), biliary atresia (n=1), portal venous thrombosis (n=1) and unknown (n=4). Thirteen babies with sepsis recovered completely with treatment, whereas the prognosis for those with perinatal hypoxia-ischemia was grave (six of seven died).

CONCLUSIONS

The findings suggest that early onset cholestatic jaundice in newborn infants is more commonly from non-hepatic causes, so it is reasonable to monitor these infants carefully for a period of time before undertaking time-consuming or invasive investigations towards a primary liver disease.

Neonatal cholestasis associated with fetal arrhythmia

We evaluated the consequence of different types of fetal arrhythmia in the development of neonatal cholestasis. The charts of 38 children born at St. Justine Hospital between 1993 and 2001 with sustained and hemodynamically significant fetal arrhythmias were studied: 19 with supraventricular tachycardia, 14 with atrial flutter, and 5 with atrio-ventricular (AV) block. Six of these 38 children presented with cholestasis. The average duration of arrhythmia was 15.7 days in the noncholestatic group, compared with 40.3 days in the cholestatic group ( P <.05). The three infants with supraventricular tachycardia who developed cholestasis survived and resolved their cholestasis, whereas 2 of 3 infants with AV block died. No infant with atrial flutter developed cholestasis. We conclude that newborns who developed tachyarrhythmia during their fetal life can show transient neonatal cholestasis. In patients with AV block, severe and irreversible liver failure could be observed. In addition, extensive collapse of the stroma and the absence of hepatocytes (foie vide) also were observed in a patient with anti-Ro antibodies.

Prolonged neonatal jaundice: When to worry and what to do

Neonatal jaundice persisting beyond 14 days of age is a common clinical scenario. The vast majority of affected children have a benign unconjugated hyperbilirubinemia, but included in this clinical presentation is a group of neonates with conjugated hyperbilirubinemia and liver disease. Early identification of liver disease improves the infant's outcome, especially for those with extrahepatic biliary atresia. The present paper reviews the approach to the neonate with prolonged jaundice, including clinical presentation, when to proceed with initial investigations, timing of referral, further investigations and management, and provides an overview of the more common causes of neonatal cholestatic liver disease.

Neonatal cholestasis

Any infant who is jaundiced beyond two to three weeks of life should be evaluated for neonatal cholestasis. Neonatal cholestasis is defined as accumulation of bile substances in blood due to impaired excretion. These infants should always have fractionated serum bilirubin levels checked to differentiate the conjugated hyperbilirubinemia of cholestasis from unconjugated hyperbilirubinemia that is usually benign and spontaneously resolves. Conjugated hyperbilirubinemia, pale stools and dark urine are the cardinal features of neonatal cholestasis. The differential diagnosis of cholestasis is extensive and a systematic approach is helpful to quickly establish the diagnosis. Biliary atresia is a common cause of neonatal cholestasis and affected infants need surgery before 60 days of life for better prognosis. Premature infants have multifactorial cholestasis and need a modified approach to the evaluation of cholestasis. Management of cholestasis is mostly supportive, consisting of medical management of complications of chronic cholestasis like pruritus and nutritional support for malabsorption and vitamin deficiency.

Increased incidence of parenteral nutrition-associated cholestasis with aminosyn PF compared to trophamine

OBJECTIVE

To compare the incidence of parenteral nutrition-associated cholestasis (PNAC) between two pediatric parenteral amino-acid formulations, Aminosyn PF (APF) and Trophamine (TA).

SETTING

Tertiary newborn intensive-care nursery.

SUBJECTS

A total of 661 neonates who received either TA or APF.

DESIGN

Retrospective. The incidence of PNAC was determined in three groups: Group I (TA, 8/19/97 to 8/19/98, n=335), Group II (APF, 8/20/98 to 1/28/99, n=157), and Group III (TA, 1/29/99 to 8/1/99, n=169).

RESULTS

No PNAC developed in any infant receiving parenteral nutrition (PN) for < 3 weeks. Of 141 patients given PN for > or =21 days, 24 were diagnosed with PNAC: Group I (TA, 10/78, 12.8%), Group II (APF, 9/27, 33.3%), and Group III (TA, 5/36, 13.9%). The incidence of PNAC was significantly higher in infants who received APF (p=0.043). Using logistic regression, only birth weight, duration of PN, and use of APF were significant risk factors for the development of PNAC. Despite an earlier initiation of enteral feedings, APF recipients developed PNAC sooner, had higher peak direct bilirubin levels, and remained jaundiced longer.

CONCLUSIONS

The use of APF was temporally associated with a greater than two-fold increase in the incidence of PNAC compared to periods of exclusive TA use. In the absence of significant differences in parenteral nutrient or energy intake in neonates who developed PNAC, we speculate that possible differences between the amino-acid compositions of TA and APF may be responsible for the observed differences in the incidence of PNAC.