Total parenteral nutrition induced liver pathology: an autopsy series of 24 newborn cases

[Clinical features and risk factors of cholestasis in small for gestational age preterm infants]

OBJECTIVES

To investigate the clinical features and risk factors of cholestasis in small for gestational age (SGA) preterm infants.

METHODS

This study selected SGA preterm infants born at less than 37 weeks of gestation and admitted to the Department of Neonatology, Children's Hospital of Soochow Universitywithin 24 hours after birth. The infants were divided into two groups: a cholestasis group and a non-cholestasis group. Clinical data from July 2017 to June 2022 were collected and retrospectively analyzed.

RESULTS

Among the 553 SGA preterm infants included, 100 infants (18.1%) developed cholestasis. The incidence rates in different gestational age and birth weight groups were as follows: extremely preterm infants 50.0%, very preterm infants 46.6%, moderate preterm infants 32.7%, and late preterm infants 9.8%; birth weight (BW) <1 000 g 60.9%, 1 000 g≤BW<1 500 g 33.9%, and 1 500 g≤BW<2 500 g 10.7%. Multivariate regression analysis showed that low birth weight, intracranial hemorrhage, duration of invasive ventilation, total amino acid accumulation in the second week, total lipid emulsion accumulation in the first week, and total lipid emulsion accumulation in the second week were independent risk factors for cholestasis in SGA preterm infants (P<0.05).

CONCLUSIONS

The incidence of cholestasis in SGA preterm infants increases with decreasing gestational age and birth weight. The occurrence of cholestasis in SGA preterm infants is influenced by multiple risk factors, including low birth weight, intracranial hemorrhage, invasive ventilation, and the accumulation of amino acids and lipid emulsions, highlighting the need for comprehensive treatment measures to reduce its occurrence.

Parenteral nutrition emulsion inhibits CYP3A4 in an iPSC derived liver organoids testing platform

OBJECTIVES

Parenteral nutrition (PN) is used for patients of varying ages with intestinal failure to supplement calories. Premature newborns with low birth weight are at a high risk for developing PN associated liver disease (PNALD) including steatosis, cholestasis, and gallbladder sludge/stones. To optimize nutrition regimens, models are required to predict PNALD.

METHODS

We have exploited induced pluripotent stem cell derived liver organoids to provide a testing platform for PNALD. Liver organoids mimic the developing liver and contain the different hepatic cell types. The organoids have an early postnatal maturity making them a suitable model for premature newborns. To mimic PN treatment we used medium supplemented with either clinoleic (80% olive oil/20% soybean oil) or intralipid (100% soybean oil) for 7 days.

RESULTS

Homogenous HNF4a staining was found in all organoids and PN treatments caused accumulation of lipids in hepatocytes. Organoids exhibited a dose dependent decrease in CYP3A4 activity and expression of hepatocyte functional genes. The lipid emulsions did not affect overall organoid viability and glucose levels had no contributory effect to the observed results.

CONCLUSIONS

Liver organoids could be utilized as a potential screening platform for the development of new, less hepatotoxic PN solutions. Both lipid treatments caused hepatic lipid accumulation, a significant decrease in CYP3A4 activity and a decrease in the RNA levels of both CYP3A4 and CYP1A2 in a dose dependent manner. The presence of high glucose had no additive effect, while Clinoleic at high dose, caused significant upregulation of interleukin 6 and TLR4 expression.

A medium-chain fatty acid analogue prevents hepatosteatosis and decreases inflammatory lipid metabolites in a murine model of parenteral nutrition-induced hepatosteatosis

BACKGROUND

Parenteral (intravenous) nutrition is lifesaving for patients with intestinal failure, but long-term use of parenteral nutrition often leads to liver disease. SEFA-6179 is a synthetic medium-chain fatty acid analogue designed to target multiple fatty acid receptors regulating metabolic and inflammatory pathways. We hypothesized that SEFA-6179 would prevent hepatosteatosis and lipotoxicity in a murine model of parenteral nutrition-induced hepatosteatosis.

METHODS

Two in vivo experiments were conducted. In the first experiment, six-week-old male mice were provided an ad lib fat-free high carbohydrate diet (HCD) for 19 days with orogastric gavage of either fish oil, medium-chain triglycerides, or SEFA-6179 at a low (0.3mmol/kg) or high dose (0.6mmol/kg). In the second experiment, six-week-old mice were provided an ad lib fat-free high carbohydrate diet for 19 days with every other day tail vein injection of saline, soybean oil lipid emulsion, or fish oil lipid emulsion. Mice then received every other day orogastric gavage of medium-chain triglyceride vehicle or SEFA-6179 (0.6mmol/kg). Hepatosteatosis was assessed by a blinded pathologist using an established rodent steatosis score. Hepatic lipid metabolites were assessed using ultra-high-performance liquid chromatography-mass spectrometry. Effects of SEFA-6179 on fatty acid oxidation, lipogenesis, and fatty acid uptake in human liver cells were assessed in vitro.

RESULTS

In the first experiment, mice receiving the HCD with either saline or medium-chain triglyceride treatment developed macrovesicular steatosis, while mice receiving fish oil or SEFA-6179 retained normal liver histology. In the second experiment, mice receiving a high carbohydrate diet with intravenous saline or soybean oil lipid emulsion, along with medium chain triglyceride vehicle treatment, developed macrovescular steatosis. Treatment with SEFA-6179 prevented steatosis. In each experiment, SEFA-6179 treatment decreased arachidonic acid metabolites as well as key molecules (diacylglycerol, ceramides) involved in lipotoxicity. SEFA-6179 increased both β- and complete fatty oxidation in human liver cells, while having no impact on lipogenesis or fatty acid uptake.

CONCLUSIONS

SEFA-6179 treatment prevented hepatosteatosis and decreased toxic lipid metabolites in a murine model of parenteral nutrition-induced hepatosteatosis. An increase in both β- and complete hepatic fatty acid oxidation may underlie the reduction in steatosis.

Composite lipid emulsion use and essential fatty acid deficiency in pediatric patients with intestinal failure with high parenteral nutrition dependence: A retrospective cohort study

BACKGROUND

Reports of essential fatty acid deficiency (EFAD) in patients receiving parenteral nutrition (PN) and a composite lipid (mixed oil intravenous lipid emulsion [MO ILE]) are predominantly when managed by lipid restriction. The objective of this study was to determine the prevalence of EFAD in patients with intestinal failure (IF) who are PN dependent without lipid restriction.

METHODS

We retrospectively evaluated patients, ages 0-17 years, followed by our intestinal rehabilitation program between November 2020 and June 2021 with PN dependency index (PNDI) of >80% on a MO ILE. Demographic data, PN composition, PN days, growth, and plasma fatty acid profile were collected. A plasma triene-tetraene (T:T) ratio >0.2 indicated EFAD. Summary statistics and Wilcoxon rank sum test evaluated to compare between PNDI category and ILE administration (grams/kilograms/day). P < 0.05 was considered significant.

RESULTS

Twenty-six patients (median age, 4.1 years [interquartile range (IQR) = 2.4-9.6]) were included. The median duration of PN was 1367 days (IQR = 824-3195). Sixteen patients had a PNDI of 80%-120% (61.5%). Fat intake for the group was 1.7 g/kg/day (IQR = 1.3-2.0). The median T:T ratio was 0.1 (IQR = 0.1-0.2) with no values >0.2. Linoleic and arachidonic acid were low in 85% and 19% of patients, respectively; however, Mead acid was normal in all patients.

CONCLUSION

This report is the largest to date on the EFA status of patients with IF on PN. These results suggest that, in the absence of lipid restriction, EFAD is not a concern when using MO ILEs in children receiving PN for IF.

Current Insights Regarding Intestinal Failure-Associated Liver Disease (IFALD): A Narrative Review

Intestinal failure-associated liver disease (IFALD) is a spectrum of liver disease including cholestasis, biliary cirrhosis, steatohepatitis, and gallbladder disease in patients with intestinal failure (IF). The prevalence of IFALD varies considerably, with ranges of 40-60% in the pediatric population, up to 85% in neonates, and between 15-40% in the adult population. IFALD has a complex and multifactorial etiology; the risk factors can be parenteral nutrition-related or patient-related. Because of this, the approach to managing IFALD is multidisciplinary and tailored to each patient based on the etiology. This review summarizes the current knowledge on the etiology and pathophysiology of IFALD and examines the latest evidence regarding preventative measures, diagnostic approaches, and treatment strategies for IFALD and its associated complications.

Intestinal failure among adults and children: Similarities and differences

Intestinal failure (IF) is a complex medical condition that is caused by a constellation of disorders, resulting in the gut's inability to adequately absorb fluids and nutrients to sustain hydration, growth, and survival, thereby requiring the use of parenteral fluid and/or nutrition. Significant advancements in intestinal rehabilitation have resulted in improved survival rates for individuals with IF. There are distinct differences, however, related to etiology, adaptive potential and complications, and medical and surgical management when comparing children with adults. The purpose of this review is to contrast the similarities and differences between these two distinct groups and provide insight for future directions, as a growing population of pediatric patients will cross into the adult world for IF management.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD)

PURPOSE

Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD).

METHODS

This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score.

RESULTS

Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers.

CONCLUSION

Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

Protocols of Investigation of Neonatal Cholestasis-A Critical Appraisal

Neonatal cholestasis (NC) starts during the first three months of life and comprises extrahepatic and intrahepatic groups of diseases, some of which have high morbimortality rates if not timely identified and treated. Prolonged jaundice, clay-colored or acholic stools, and choluria in an infant indicate the urgent need to investigate the presence of NC, and thenceforth the differential diagnosis of extra- and intrahepatic causes of NC. The differential diagnosis of NC is a laborious process demanding the accurate exclusion of a wide range of diseases, through the skillful use and interpretation of several diagnostic tests. A wise integration of clinical-laboratory, histopathological, molecular, and genetic evaluations is imperative, employing extensive knowledge about each evaluated disease as well as the pitfalls of each diagnostic test. Here, we review the difficulties involved in correctly diagnosing the cause of cholestasis in an affected infant.

Comparing Serum Matrix Metalloproteinase-7 in Parenteral Nutrition-Associated Liver Disease and Biliary Atresia

In this cross-sectional study, serum matrix metalloproteinase-7 levels were significantly lower in infants with jaundice and parenteral nutrition-associated liver disease compared with those with confirmed biliary atresia. Serum metalloproteinase-7 may aid in excluding biliary atresia and thus may minimize invasive testing in infants with a history of parenteral nutrition.

IFALD in children: What's new? A narrative review

Intestinal failure-associated liver disease (IFALD) is a progressive liver disease complicating intestinal failure (IF). It is a preventable and reversible condition, but at the same time, a potential cause of liver cirrhosis and an indication to combined or non-combined liver and small bowel transplantation. The diagnostic criteria are not yet standardized, so that its prevalence varies widely in the literature. Pathophysiology seems to be multifactorial, related to different aspects of intestinal failure and not only to the long-term parenteral nutrition treatment. The survival rates of children with IF have increased, so that the main problems today are preventing complications and ensuring a good quality of life. IFALD is one of the most important factors that limit long-term survival of patients with IF. For this reason, more and more interest is developing around it and the number of published articles is increasing rapidly. The purpose of this narrative review was to focus on the main aspects of the etiology, pathophysiology, management, prevention, and treatment of IFALD, based on what has been published mainly in the last 10 years. Controversies and current research gaps will be highlighted with the aim to pave the way for new project and high-quality clinical trials.

Management of pediatric intestinal failure related to short bowel syndrome

Intestinal failure (IF) secondary to short bowel syndrome is a challenging and complex medical condition with significant risk for surgical and medical complications. Significant advancements in the care of this patient population have led to improved survival rates. Due to their intensive medical needs children with IF are at risk for long-term complications that require comprehensive management and close monitoring. The purpose of this paper is to review the available literature emphasizing the surgical aspects of care for children with IF secondary to short bowel syndrome. A key priority in the surgical care of this patient population includes strategies to preserve available bowel and maximize its function. Utilization of novel surgical techniques and autologous bowel reconstruction can have a significant impact on children with IF secondary to short bowel syndrome related to the function of their bowel and ability to achieve enteral autonomy. It is also important to understand the potential long-term complications to ensure strategies are put in place to mitigate risk with early detection to improve long-term outcomes.

Intestinal failure-associated liver disease in the neonatal ICU: what we know and where we're going

PURPOSE OF REVIEW

Parenteral nutrition is an integral part of the care of infants in the neonatal ICU. However, prolonged use of parenteral nutrition can be associated with adverse outcomes, most notably parenteral nutrition-associated liver disease, now known as intestinal failure-associated liver disease (IFALD). This review highlights pertinent developments in the epidemiology of IFALD as it pertains to neonates and showcases recent advances in the pathophysiology, treatment, and outcomes of neonates with IFALD.

RECENT FINDINGS

The role of intravenous lipid emulsions in the pathogenesis, prevention, and treatment of IFALD remains a target for investigative studies. Recent data continues to support the use of fish-oil based intravenous lipids, but its use is limited due to concerns for essential fatty acid deficiency. Use of soy-based lipids and mixed lipids is not wrought with such concerns as these are often used at greater doses but their use is limited due to higher proinflammatory fatty acid content, increased phytosterols and decreased antioxidants, risk factors for the development of IFALD.

SUMMARY

Hepatic complications may limit the use of parenteral nutrition in the neonatal ICU. However, the pathophysiology of IFALD is continuing to be further elucidated and novel targets are being developed for the treatment of IFALD. As noninvasive disease monitoring strategies continue to be developed, early enteral nutrition ameliorates the risk of IFALD and should be considered when possible.

Light protection of parenteral nutrition, cholestasis, and other prematurity-related morbidities in premature infants

INTRODUCTION

Parenteral Nutrition (PN) can lead to intestinal failure associated liver disease (IFALD). There are no human studies to date studying specifically the benefits of light-protection on neonatal IFALD. Recently, the European Medicines Agency and the American Society for Parenteral and Enteral Nutrition (ASPEN) both recommended full light protection of PN to reduce the risk of adverse clinical outcomes.

OBJECTIVE

The primary objective of this study was to evaluate the impact of light-protecting PN on the incidence of cholestasis and peak direct bilirubin levels in premature infants.

STUDY DESIGN

Retrospective chart review of preterm infants requiring PN for a minimum of 2 weeks with or without light-protection. After light protection of the PN solution, primary outcomes (including cholestasis and direct bilirubin levels) of both groups were compared. Secondary outcomes include evaluation of bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), sepsis and mortality.

RESULTS

A total of 50 preterm infants <37 weeks gestation were included, 25 infants in each group. There was a statistically significant decrease in the rate of cholestasis (12 vs. 3, p = 0.005), median peak direct bilirubin levels (1.7 vs. 0.9 mg/dL, p = 0.02) and total bilirubin levels (4.1 vs. 3.4, p = 0.05) in the light-protection group compared to no light-protection group. There was a decrease in the incidence of severe BPD (with an increase of mild BPD, resulting in the same overall BPD rate) in the light-protection compared to no light-protection group (7 vs. 15, p = 0.0223). There was no difference in NEC, ROP, sepsis or mortality.

CONCLUSION

Our study supports that the practice of light-protecting PN may reduce the incidence of IFALD in premature infants. Moreover, there was a trend toward decreased incidence of severe BPD in the light-protection group. Further light protection studies are needed to confirm these findings.

Fatal accidental lipid overdose with intravenous composite lipid emulsion in a premature newborn: a case report

BACKGROUND

Tenfold or more overdose of a drug or preparation is a dreadful adverse event in neonatology, often due to an error in programming the infusion pump flow rate. Lipid overdose is exceptional in this context and has never been reported during the administration of a composite intravenous lipid emulsion (ILE).

CASE PRESENTATION

Twenty-four hours after birth, a 30 weeks' gestation infant with a birthweight of 930 g inadvertently received 28 ml of a composite ILE over 4 h. The ILE contained 50% medium-chain triglycerides and 50% soybean oil, corresponding to 6 g/kg of lipids (25 mg/kg/min). The patient developed acute respiratory distress with echocardiographic markers of pulmonary hypertension and was treated with inhaled nitric oxide and high-frequency oscillatory ventilation. Serum triglyceride level peaked at 51.4 g/L, 17 h after the lipid overload. Triple-volume exchange transfusion was performed twice, decreasing the triglyceride concentration to < 10 g/L. The infant's condition remained critical, with persistent bleeding and shock despite supportive treatment and peritoneal dialysis. Death occurred 69 h after the overdose in a context of refractory lactic acidosis.

CONCLUSIONS

Massive ILE overdose is life-threatening in the early neonatal period, particularly in premature and hypotrophic infants. This case highlights the vigilance required when ILEs are administered separately from other parenteral intakes. Exchange transfusion should be considered at the first signs of clinical or biological worsening to avoid progression to multiple organ failure.

NF-κB Regulation of LRH-1 and ABCG5/8 Potentiates Phytosterol Role in the Pathogenesis of Parenteral Nutrition-Associated Cholestasis

BACKGROUND AND AIMS

Chronically administered parenteral nutrition (PN) in patients with intestinal failure carries the risk for developing PN-associated cholestasis (PNAC). We have demonstrated that farnesoid X receptor (FXR) and liver X receptor (LXR), proinflammatory interleukin-1 beta (IL-1β), and infused phytosterols are important in murine PNAC pathogenesis. In this study we examined the role of nuclear receptor liver receptor homolog 1 (LRH-1) and phytosterols in PNAC.

APPROACH AND RESULTS

In a C57BL/6 PNAC mouse model (dextran sulfate sodium [DSS] pretreatment followed by 14 days of PN; DSS-PN), hepatic nuclear receptor subfamily 5, group A, member 2/LRH-1 mRNA, LRH-1 protein expression, and binding of LRH-1 at the Abcg5/8 and Cyp7a1 promoter was reduced. Interleukin-1 receptor-deficient mice (Il-1r^-/- /DSS-PN) were protected from PNAC and had significantly increased hepatic mRNA and protein expression of LRH-1. NF-κB activation and binding to the LRH-1 promoter were increased in DSS-PN PNAC mice and normalized in Il-1r^-/- /DSS-PN mice. Knockdown of NF-κB in IL-1β-exposed HepG2 cells increased expression of LRH-1 and ABCG5. Treatment of HepG2 cells and primary mouse hepatocytes with an LRH-1 inverse agonist, ML179, significantly reduced mRNA expression of FXR targets ATP binding cassette subfamily C member 2/multidrug resistance associated protein 2 (ABCC2/MRP2), nuclear receptor subfamily 0, groupB, member 2/small heterodimer partner (NR0B2/SHP), and ATP binding cassette subfamily B member 11/bile salt export pump (ABCB11/BSEP). Co-incubation with phytosterols further reduced expression of these genes. Similar results were obtained by suppressing the LRH-1 targets ABCG5/8 by treatment with small interfering RNA, IL-1β, or LXR antagonist GSK2033. Liquid chromatography-mass spectrometry and chromatin immunoprecipitation experiments in HepG2 cells showed that ATP binding cassette subfamily G member 5/8 (ABCG5/8) suppression by GSK2033 increased the accumulation of phytosterols and reduced binding of FXR to the SHP promoter. Finally, treatment with LRH-1 agonist, dilauroyl phosphatidylcholine (DLPC) protected DSS-PN mice from PNAC.

CONCLUSIONS

This study suggests that NF-κB regulation of LRH-1 and downstream genes may affect phytosterol-mediated antagonism of FXR signaling in the pathogenesis of PNAC. LRH-1 could be a potential therapeutic target for PNAC.

Liver injury after small bowel resection is prevented in obesity-resistant 129S1/SvImJ mice

Intestinal failure-associated liver disease is a major morbidity associated with short bowel syndrome. We sought to determine if the obesity-resistant mouse strain (129S1/SvImJ) conferred protection from liver injury after small bowel resection (SBR). Using a parenteral nutrition-independent model of resection-associated liver injury, C57BL/6J and 129S1/SvImJ mice underwent a 50% proximal SBR or sham operation. At postoperative week 10, hepatic steatosis, fibrosis, and cholestasis were assessed. Hepatic and systemic inflammatory pathways were evaluated using oxidative markers and abundance of tissue macrophages. Potential mechanisms of endotoxin resistance were also explored. Serum lipid levels were elevated in all mouse lines. Hepatic triglyceride levels were no different between mouse strains, but there was an increased accumulation of free fatty acids in the C57BL/6J mice. Histological and serum markers of hepatic fibrosis, steatosis, and cholestasis were significantly elevated in resected C57BL/6J SBR mice as well as oxidative stress markers and macrophage recruitment in both the liver and visceral white fat in C57BL/6J mice compared with sham controls and the 129S1/SvImJ mouse line. Serum endotoxin levels were significantly elevated in C57BL/6J mice with significant elevation of hepatic TLR4 and reduction in PPARα expression levels. Despite high levels of serum lipids, 129S1/SvImJ mice did not develop liver inflammation, fibrosis, or cholestasis after SBR, unlike C57BL/6J mice. These data suggest that the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 contribute to the liver injury seen in C57BL/6J mice with short bowel syndrome.NEW & NOTEWORTHY Unlike C57BL/6 mice, the 129S1/SvImJ strain is resistant to liver inflammation and injury after small bowel resection. These disparate outcomes are likely due to the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 in C57BL/6 mice with short bowel syndrome.

Intestinal Failure-Associated Liver Disease in Neonates

Intestinal failure-associated liver disease (IFALD) is common in neonates who suffer from intestinal failure and rely on parenteral nutrition. The etiology is multifactorial, relating to the infant's underlying cause of intestinal failure and other infant factors such as prematurity. Management of the disease includes transitioning to enteral feedings as soon as is safe for the infant. In infants who continue to rely on parenteral nutrition, alternative lipid emulsions and other medications may be used. This article reviews the epidemiology and factors that contribute to IFALD in neonates, in addition to management strategies.

Translational Advances in Pediatric Nutrition and Gastroenterology: New Insights from Pig Models

Pigs are increasingly important animals for modeling human pediatric nutrition and gastroenterology and complementing mechanistic studies in rodents. The comparative advantages in size and physiology of the neonatal pig have led to new translational and clinically relevant models of important diseases of the gastrointestinal tract and liver in premature infants. Studies in pigs have established the essential roles of prematurity, microbial colonization, and enteral nutrition in the pathogenesis of necrotizing enterocolitis. Studies in neonatal pigs have demonstrated the intestinal trophic effects of akey gut hormone, glucagon-like peptide 2 (GLP-2), and its role in the intestinal adaptation process and efficacy in the treatment of short bowel syndrome. Further, pigs have been instrumental in elucidating the physiology of parenteral nutrition-associated liver disease and the means by which phytosterols, fibroblast growth factor 19, and a new generation of lipid emulsions may modify disease. The premature pig will continue to be a valuable model in the development of optimal infant diets (donor human milk, colostrum), specific milk bioactives (arginine, growth factors), gut microbiota modifiers (pre-, pro-, and antibiotics), pharmaceutical drugs (GLP-2 analogs, FXR agonists), and novel diagnostic tools (near-infrared spectroscopy) to prevent and treat these pediatric diseases.

Intestinal failure-associated liver disease (IFALD): insights into pathogenesis and advances in management

Premature infants and children with intestinal failure (IF) or short bowel syndrome are susceptible to intestinal failure-associated liver disease (IFALD, previously referred to as parenteral nutrition-associated liver disease, or PNALD). IFALD in children is characterized by progressive cholestasis and biliary fibrosis, and steatohepatitis in adults, and is seen in individuals dependent upon prolonged administration of PN. Many factors have been proposed as contributing to the pathogenesis of IFALD. In recent years, the focus has been on the potential synergistic roles of the intestinal microbiome, increased intestinal permeability, activation of hepatic innate immune pathways, and the use of intravenous soybean-oil-based intravenous lipid emulsions (SO-ILE). In vitro and in vivo studies have identified stigmasterol, a component of the plant sterols present in SO-ILE, as playing an important role. Although various strategies have been adopted to prevent or reverse IFALD, most suffer from a lack of strong evidence supported by well-designed, prospective clinical trials with clearly defined endpoints. Reduction in the amount of SO-ILEs or replacement with non-SO-ILEs has been shown to reverse IFALD although safety and long-term effectiveness have not been studied. Medical and surgical modalities to increase intestinal adaptation, advance enteral feedings, and prevent central line bloodstream infections are also important preventative strategies. There is a continued need to conduct high-quality, prospective trials with clearly define outcome measures to ascertain the potential benefits of these strategies.

Neonatal cholestasis: recent insights

Background

Neonatal physiological jaundice is a common benign condition that rarely extends behind the second week of life; however, it may interfere with the diagnosis of a pathological condition termed neonatal cholestasis (NC). The latter is a critical, uncommon problem characterized by conjugated hyperbilirubinaemia. This review aims to highlight the differences between physiological and pathological jaundice, identify different causes of NC, and provide a recent approach to diagnosis and management of this serious condition.

Main text

NC affects 1/2500 live births, resulting in life-threatening complications due to associated hepatobiliary or metabolic abnormalities. NC is rarely benign and indicates the presence of severe underlying disease. If jaundice extends more than 14 days in full-term infants or 21 days in preterm infants, the serum bilirubin level fractionated into conjugated (direct) and unconjugated (indirect) bilirubin should be measured. A stepwise diagnostic approach starts with obtaining a complete history, and a physical examination which are valuable for the rapid diagnosis of the underlying disease. The most frequently diagnosed causes of NC are biliary atresia (BA) and idiopathic neonatal hepatitis (INH). The early diagnosis of NC ensures more accurate management and better prognosis. Despite the unavailability of any specific treatments for some causes of NC, the patient can benefit from nutritional management and early medical intervention. Future research should attempt to shed light on methods of screening for NC, especially for causes that can be effectively treated either through proper nutritional support, appropriate chemotherapeutic management, or timely surgical intervention.

Conclusion

Further attention should be paid for diagnosis and treatment of NC as it may be misdiagnosed as physiological jaundice; this may delay the proper management of the underlying diseases and aggravates its complications.

Something old, something new: liver injury associated with total parenteral nutrition therapy and immune checkpoint inhibitors

Drug-induced liver injury (DILI) is a challenging and constantly changing field. The pathologist plays a key role in interpreting liver biopsies by classifying the pattern of injury, grading the severity of injury, and evaluating for other possible causes. Reports of iatrogenic liver injury are reviewed here with a focus on total parenteral nutrition (ie, intestinal failure-associated liver disease [IFALD]) and immune checkpoint inhibitors (ICIs). The hallmark features of IFALD are cholestasis and steatosis. Cholestasis is more common in infants, whereas steatosis and steatohepatitis are more commonly seen in older children and adults. Infants tend to have a faster progression to fibrosis and cirrhosis. Perivenular fibrosis and ductopenia may also be seen in IFALD. Although fish oil-based lipid emulsions can reverse cholestasis, recent studies have shown persistent or progressive fibrosis. ICI-induced liver injury usually presents as an acute hepatitis with features similar to those seen in idiopathic autoimmune hepatitis and drug-induced autoimmune hepatitis. However, it lacks a prominent plasma cell infiltrate and serological markers of autoimmune hepatitis. Other features such as fibrin ring granulomas and cholangitis have also been reported in association with ICIs. Treatment for ICI-induced liver injury includes corticosteroids and other immunosuppressants.

Estimating fetal cholesterol synthesis rates by cord blood analysis in intrauterine growth restriction and normally grown fetuses

BACKGROUND

Cholesterol is an essential component in human development. In fetuses affected by intrauterine growth restriction (IUGR), fetal blood cholesterol levels are low. Whether this is the result of a reduced materno-fetal cholesterol transport, or due to low fetal de novo synthesis rates, remains a matter of debate. By analyzing cholesterol interbolites and plant sterols we aimed at deeper insights into transplacental cholesterol transport and fetal cholesterol handling in IUGR with potential targets for future therapy. We hypothesized that placental insufficiency results in a diminished cholesterol supply to the fetus.

METHODS

Venous umbilical cord sera were sampled post-partum from fetuses delivered between 24 weeks of gestation and at full term. IUGR fetuses were matched to 49 adequate-for-age delivered preterm and term neonates (CTRL) according to gestational age at delivery. Cholesterol was measured by gas chromatography-flame ionization detection using 5a-cholestane as internal standard. Cholesterol precursors and synthesis markers, such as lanosterol, lathosterol, and desmosterol, the absorption markers, 5α-cholestanol and plant sterols, such as campesterol and sitosterol, as well as enzymatically oxidized cholesterol metabolites (oxysterols), such as 24S- or 27-hydroxycholesterol, were analyzed by gas chromatography-mass spectrometry, using epicoprostanol as internal standard for the non-cholesterol sterols and deuterium labeled oxysterols for 24S- and 27-hydroxycholesterol.

RESULTS

Mean cholesterol levels were 25% lower in IUGR compared with CTRL (p < 0.0001). Lanosterol and lathosterol to cholesterol ratios were similar in IUGR and CTRL. In relation to cholesterol mean, desmosterol, 24S-hydroxycholesterol, and 27-hydroxycholesterol levels were higher by 30.0, 39.1 and 60.7%, respectively, in IUGR compared to CTRL (p < 0.0001). Equally, 5α-cholestanol, campesterol, and β-sitosterol to cholesterol ratios were higher in IUGR than in CTRL (17.2%, p < 0.004; 33.5%, p < 0.002; 29.3%, p < 0.021).

CONCLUSIONS

Cholesterol deficiency in IUGR is the result of diminished fetal de novo synthesis rates rather than diminished maternal supply. However, increased oxysterol- and phytosterol to cholesterol ratios suggest a lower sterol elimination rate. This is likely caused by a restricted hepatobiliary function. Understanding the fetal cholesterol metabolism is important, not only for neonatal nutrition, but also for the development of strategies to reduce the known risk of future cardiovascular diseases in the IUGR fetus.

Noninvasive assessment of liver fibrosis in pediatric intestinal failure patients using liver stiffness measurement by Vibration-Controlled Transient Elastography

PURPOSE

The purpose of this study was to evaluate the diagnostic utility of noninvasive Vibration-Controlled Transient Elastography (VCTE) for assessing liver fibrosis in pediatric intestinal failure (PIF) patients.

METHODS

Data from children with severe intestinal failure (≥90 days parenteral nutrition dependence) who underwent liver stiffness measurement (LSM), as measured by VCTE, at our institution between December 2015 and March 2018 were reviewed. LSM was compared to METAVIR fibrosis score (F0-F4) on liver biopsy performed within 1 year of VCTE.

RESULTS

Seventy children underwent 75 LSM. Sixty-three patients (38% female) had at least one valid LSM, and 63% had a history of cholestasis (direct bilirubin ≥2 mg/dL). Median (IQR) age at first valid LSM was 4.5 years (2.6, 8.7). Sixteen patients had a liver biopsy. LSM differentiated between METAVIR F0-F1 (n = 6) and F2-F4 (n = 10) with an area under the receiver operating characteristic (AUROC) curve of 0.883 (95% CI: 0.686-0.999). The optimal cut-point derived to predict F2-F4 was an LSM ≥6 kPa (sensitivity 80%, specificity 100%).

CONCLUSION

LSM as determined by VCTE can distinguish mild (F0-F1) from moderate/severe (F2-F4) liver fibrosis in PIF. VCTE could allow for serial noninvasive monitoring of liver injury, potentially facilitating timely modifications to hepatoprotective management.

TYPE OF STUDY

Study of Diagnostic Test.

LEVEL OF EVIDENCE

II.

Predictive value of the aspartate aminotransferase to platelet ratio index for parenteral nutrition associated cholestasis in extremely low birth weight infants

Background

Parenteral nutrition (PN) improves the survival of premature infants. However, prolonged PN increases the risk of PN-associated cholestasis (PNAC).

Objective

We aimed to evaluate the predictive value of aspartate aminotransferase (AST)-to-platelet ratio index (APRI) for PNAC in infants with extremely low birth weight (ELBW, birth weight < 1000 g) infants.

Methods

We retrospectively reviewed the medical records of ELBW infants from March 2010 to February 2017. Clinical data and the serial APRI, AST, alanine aminotransferase (ALT), AST-to-ALT ratio, and direct bilirubin (DB) were analyzed. PNAC was diagnosed in infants with a history of PN for at least 2 weeks and direct bilirubin concentrations > 2 mg/dL after other causes of neonatal cholestasis were excluded.

Results

Among the 179 eligible ELBW infants, 56 (31.3%) were diagnosed with PNAC. APRI significantly differed between infants with PNAC and those without PNAC. The best APRI cut-off point was 0.410 at 2 weeks after the start of PN (area under the receiver operating characteristic curve = 0.752, p < 0.05; positive predictive value, 50.6%; negative predictive value, 84.1%).

Conclusion

APRI at 2 weeks after PN could be a reliable predictor of PNAC development in ELBW infants on PN.

A Mixed Lipid Emulsion for Prevention of Parenteral Nutrition Associated Cholestasis in Extremely Low Birth Weight Infants: A Randomized Clinical Trial

OBJECTIVES

To examine whether a mixed lipid emulsion reduces the incidence of parenteral nutrition associated cholestasis (PNAC) in extremely low birth weight (ELBW, <1000 g) infants.

STUDY DESIGN

This double-blind randomized trial of 230 ELBW infants (June 2012-October 2015) was performed at a single level IV neonatal intensive care unit. Patients received either a mixed lipid emulsion composed of soybean oil, medium chain triglycerides, olive oil, and fish oil-(intervention) or a soybean oil-based lipid emulsion (control) for parenteral nutrition. The primary outcome measure was PNAC (conjugated bilirubin >1.5 mg/dL [25 µmol/L] at 2 consecutive measurements). The study was powered to detect a reduction of PNAC from 25% to 10%.

RESULTS

Reasons for noneligibility of 274 infants screened were refusal to participate (n = 16), death (n = 10), withdrawal of treatment (n = 5), higher order multiples (n = 9), and parents not available for consent (n = 4). Intention to treat analysis was carried out in 223 infants (7 infants excluded after randomization). Parenteral nutrition associated cholestasis was 11 of 110 (10.1%) in the intervention and 18 of 113 (15.9%) in the control group (P = .20). Multivariable analyses showed no statistically significant difference in the intention to treat (aOR 0.428, 95% CI 0.155-1.187; P = .10) or per protocol population (aOR 0.457, 95% CI 0.155-1.347; P = .16). There was no statistically significant effect on any other neonatal morbidity.

CONCLUSIONS

The incidence of parenteral nutrition associated cholestasis was not significantly reduced using a mixed lipid emulsion in ELBW infants.

TRIAL REGISTRATION

ClinicalTrials.govNCT01585935.

Predictive Value of the Aspartate Aminotransferase to Platelet Ratio Index for Parenteral Nutrition-Associated Cholestasis in Premature Infants With Intestinal Perforation

BACKGROUND

Parenteral nutrition-associated cholestasis (PNAC) is a major cause of morbidity and mortality in premature infants. Early predictors of PNAC would have clinical value. We sought to evaluate risk factors and liver function testing as predictors of PNAC in premature infants with intestinal perforation.

METHODS

Medical records of infants with a gestational age <34 weeks, birth weight <2000 g, and intestinal perforation due to either necrotizing enterocolitis or spontaneous intestinal perforation were reviewed. We analyzed clinical data and the maximum values of the aspartate aminotransferase (AST) to platelet ratio index (APRI), alanine aminotransferase (ALT), AST to ALT ratio, and total bilirubin (TB).

RESULTS

Sixty infants were identified, 17 infants with PNAC and 43 infants without PNAC. Sepsis, time to initiation of enteral feeds after perforation, and duration of PN were associated with PNAC. Within 2 weeks following intestinal perforation, APRI, ALT, and TB each differed significantly between infants who later developed PNAC and those that did not. The best APRI cut-point was 0.4775 within 2 weeks after perforation (area under the receiver operating characteristic curve, 0.90; positive predictive value, 85%; and negative predictive value, 87%); the cut-point for ALT was 13.5 (0.90, 85%, 84%), and the cut-point for TB was 3.55 (0.82, 69%, 83%), respectively, at 2 weeks after perforation. AST to ALT ratio did not differ between groups.

CONCLUSIONS

APRI and ALT had reasonable predictive value for PNAC in premature infants with intestinal perforation, with the APRI the best predictor within 2 weeks after perforation.

Long-term outcomes of pediatric intestinal failure

Management of pediatric intestinal failure has evolved in recent decades, with improved survival since the advent of specialized multidisciplinary intestinal failure centers. Though sepsis and intestinal failure associated liver disease still contribute to mortality, we now have growing data on the long-term outcomes for this population. While intestinal adaptation and parenteral nutrition weaning is most rapid during the first year on parenteral support, achievement of enteral autonomy is possible even after many years as energy and protein requirements decline dramatically with age. Intestinal transplant is an option for patients experiencing complications of long-term parenteral nutrition who are expected to have permanent intestinal failure, but outcomes are hindered by immunosuppression-related complications. Much of the available data comes from single center retrospective reports, with variable inclusion criteria, intestinal failure definitions, and follow-up durations; this limits the ability to analyze outcomes and identify best practices. As most children now survive long-term, the focus of management has shifted to the avoidance and management of comorbidities, support of normal growth and development, and optimization of quality of life for these medically and surgically complex patients.

Pediatric intestinal failure-associated liver disease

PURPOSE OF REVIEW

The goal of this review is to provide updates on the definition, pathophysiology, treatment, and prevention of intestinal failure-associated liver disease (IFALD) that are relevant to care of pediatric patients.

RECENT FINDINGS

Current literature emphasizes the multifactorial nature of IFALD. The pathogenesis is still largely unknown; however, molecular pathways have been identified. Key to these pathways are proinflammatory cytokines involved in hepatic inflammation and bile acids synthesis such as Toll-like receptor 4 and farnesoid X receptor, respectively. Research for prevention and treatment is aimed at alleviating risk factors associated with IFALD, principally those associated with parental nutrition. Multiple nutrients and amino acids are relevant to the development of IFALD, but lipid composition has been the primary focus. Lipid emulsions with a lower ratio of omega-6-to-omega-3 polyunsaturated fatty acids (FAs) appear to improve bile flow and decrease intrahepatic inflammation. Long-term consequences of these alternative lipid emulsions are yet to be determined.

SUMMARY

IFALD remains the greatest contributor of mortality in patients with intestinal failure. Many factors contribute to its development, namely, alterations in the gut microbiome, sepsis, and lack of enteral intake. Novel combinations of lipid formulations are promising alternatives to purely soy-based formulas to reduce cholestasis.

Persistence of hepatic fibrosis in pediatric intestinal failure patients treated with intravenous fish oil lipid emulsion

BACKGROUND

Pediatric intestinal failure (PIF) is a life-altering chronic condition with significant morbidity and mortality. Omegaven® therapy has been used to treat children with advanced intestinal failure associated liver disease. Our objective was to determine the evolution of hepatic fibrosis in PIF patients who received Omegaven® and describe their clinical outcome.

METHODS

A retrospective review in PIF patients who received Omegaven® was performed. Patients were included if they had liver biopsies completed before Omegaven® therapy and after resolution of hyperbilirubinemia. Biopsy results were evaluated to determine the degree of fibrosis, inflammation, and cholestasis. Clinical and biochemical data was collected.

RESULTS

Six patients were identified. Assessment of fibrosis at last follow-up demonstrated improvement in 2 patients and progression or stable fibrosis in 4/6. All patients demonstrated reduction in cholestasis and inflammation. One patient received a liver/intestine transplant and a second is listed, both of them with progressive fibrosis. One patient achieved full enteral nutrition, while the rest remain partially parenteral nutrition dependent.

CONCLUSION

Use of Omegaven® is associated with reduced cholestasis and inflammation, but with persistence or worsening of fibrosis in some patients. A subset of patients with progressive fibrosis may develop portal hypertension and progressive liver disease.

Packed red blood cell transfusions as a risk factor for parenteral nutrition associated liver disease in premature infants

AIM

To determine if packed red blood cell transfusions contribute to the development of parenteral nutrition associated liver disease.

METHODS

A retrospective chart review of 49 premature infants on parenteral nutrition for > 30 d who received packed red blood cell (PRBC) transfusions was performed. Parenteral nutrition associated liver disease was primarily defined by direct bilirubin (db) > 2.0 mg/dL. A high transfusion cohort was defined as receiving > 75 mL packed red blood cells (the median value). Kaplan-Meier plots estimated the median volume of packed red blood cells received in order to develop parenteral nutrition associated liver disease.

RESULTS

Parenteral nutritional associated liver disease (PNALD) was noted in 21 (43%) infants based on db. Among the 27 high transfusion infants, PNALD was present in 17 (64%) based on elevated direct bilirubin which was significantly greater than the low transfusion recipients. About 50% of the infants, who were transfused 101-125 mL packed red blood cells, developed PNALD based on elevation of direct bilirubin. All infants who were transfused more than 200 mL of packed red blood cells developed PNALD. Similar results were seen when using elevation of aspartate transaminase or alanine transaminase to define PNALD.

CONCLUSION

In this retrospective, pilot study there was a statistically significant correlation between the volume of PRBC transfusions received by premature infants and the development of PNALD.

Aggressive nutrition in extremely low birth weight infants: impact on parenteral nutrition associated cholestasis and growth

Background

Parenteral nutrition associated cholestasis (PNAC) is a frequently observed pathology in extremely low birth weight (ELBW) infants. Its pathogenesis is determined by the composition and duration of parenteral nutrition (PN) as well as the tolerance of enteral feeds (EF). “Aggressive” nutrition is increasingly used in ELBW infants to improve postnatal growth. Little is known about the effect of “aggressive” nutrition on the incidence of PNAC. We analyzed the influence of implementing an “aggressive” nutritional regimen on the incidence of PNAC and growth in a cohort of ELBW infants.

Methods

ELBW infants were nourished using a “conservative” (2005–6; n = 77) or “aggressive” (2007–9; n = 85) nutritional regimen that differed in the composition of PN after birth as well as the composition and timing of advancement of EFs. We analyzed the incidence of PNAC (conjugated bilirubin > 1.5 mg/dl (25 µmol/l)) corrected for confounders of cholestasis (i.e., NEC and/or gastrointestinal surgery, sepsis, birth weight, Z-score of birth weight, time on PN and male sex), growth until discharge (as the most important secondary outcome) and neonatal morbidities.

Results

The incidence of PNAC was significantly lower during the period of “aggressive” vs. “conservative “nutrition (27% vs. 46%, P < 0.05; adjusted OR 0.275 [0.116–0.651], P < 0.01). Body weight (+411g), head circumference (+1 cm) and length (+1 cm) at discharge were significantly higher. Extra-uterine growth failure (defined as a Z-score difference from birth to discharge lower than −1) was significantly reduced for body weight (85% vs. 35%), head circumference (77% vs. 45%) and length (85% vs. 65%) (P < 0.05). The body mass index (BMI) at discharge was significantly higher (11.1 vs. 12.4) using “aggressive” nutrition and growth became more proportionate with significantly less infants being discharged below the 10th BMI percentile (44% vs. 9%), while the percentage of infants discharged over the 90th BMI percentile (3% vs. 5%) did not significantly increase.

Discussion

“Aggressive” nutrition of ELBW infants was associated with a significant decrease of PNAC and marked improvement of postnatal growth.

Predictors of failure of fish-oil therapy for intestinal failure-associated liver disease in children

BACKGROUND

Parenteral fish-oil (FO) therapy is a safe and effective treatment for intestinal failure-associated liver disease (IFALD). Patients whose cholestasis does not resolve with FO may progress to end-stage liver disease.

OBJECTIVE

We sought to identify factors associated with the failure of FO therapy in treating IFALD to guide prognostication and referral guidelines.

DESIGN

Prospectively collected data for patients treated with FO at Boston Children's Hospital from 2004 to 2014 were retrospectively reviewed. Resolution of cholestasis was defined as sustained direct bilirubin (DB) <2 mg/dL, and treatment failure as liver transplantation or death while DB was >2 mg/dL as of July 2015. Demographics, laboratory values, and medical history at FO therapy initiation were compared between patients who achieved resolution of cholestasis and those who failed therapy.

RESULTS

Among 182 patients treated with FO, 86% achieved resolution of cholestasis and 14% failed therapy. Patients who failed therapy had median (IQR) lower birth weight [1020 g (737, 1776 g) compared with 1608 g (815, 2438 g); P = 0.03] and were older at FO initiation [20.4 wk (9.9, 38.6 wk) compared with 11.7 wk (7.3, 21.4 wk); P = 0.02] than patients whose cholestasis resolved. Patients who failed therapy had more advanced liver disease at therapy initiation than patients whose cholestasis resolved, as evidenced by lower median (IQR) γ-glutamyltransferase [54 U/L (41, 103 U/L) compared with 112 U/L (76, 168 U/L); P < 0.001], higher DB [10.4 mg/dL (7.5, 14.1 mg/dL) compared with 4.4 mg/dL (3.1, 6.6 mg/dL); P < 0.001], and a higher pediatric end-stage liver disease (PELD) score [22 (14, 25) compared with 12 (7, 15); P < 0.001]. A PELD score of ≥15, history of gastrointestinal bleeding, age at FO initiation ≥16 wk, presence of nongastrointestinal comorbidities, and mechanical ventilation at FO initiation were independent predictors of treatment failure.

CONCLUSIONS

Most infants with IFALD responded to FO therapy with resolution of cholestasis, and liver transplantation was rarely required. Early FO initiation once biochemical cholestasis is detected in parenteral nutrition-dependent patients is recommended. This trial was registered at clinicaltrials.gov as NCT00910104.

Enteral autonomy, cirrhosis, and long term transplant-free survival in pediatric intestinal failure patients

PURPOSE

Patient selection for transplant evaluation in pediatric intestinal failure is predicated on the ability to assess long-term transplant-free survival. In light of trends toward improved survival of intestinal failure patients in recent decades, we sought to determine if the presence of biopsy-proven hepatic cirrhosis or the eventual achievement of enteral autonomy were associated with transplant-free survival.

METHODS

After IRB approval, records of all pediatric intestinal failure patients (parenteral nutrition (PN) >90 days) treated at a single intestinal failure center from February 2002 to September 2014 were reviewed. Chi-squared, Mann-Whitney, and log-rank testing were performed as appropriate.

RESULTS

Of 313 patients, 174 eventually weaned off PN. Liver biopsies were available in 126 patients (most common indication was intestinal failure associated liver disease, IFALD), and 23 met histologic criteria for cirrhosis. Transplant-free survival for the whole cohort of 313 patients was 94.7% at 1 year and 89.2% at 5 years. Among patients with liver biopsies, transplant-free survival in cirrhotics vs. noncirrhotics was 95.5% vs. 94.1% at one year and 95.5% vs. 86.7% at 5 years (P=0.29). Transplant-free survival in patients who achieved enteral autonomy compared with patients who remained PN dependent was 98.2% vs. 90.3% at one year and 98.2% vs. 76.9% at 5 years (P<0.001). There was no association between cirrhosis and eventual enteral autonomy (P=0.88).

CONCLUSIONS

Achieving enteral autonomy was associated with improved transplant-free survival in pediatric intestinal failure patients. There was no association between histopathological diagnosis of cirrhosis and transplant-free survival in the cohort. These data suggest that automatic transplant referral may not be required for histopathological diagnosis of cirrhosis alone, and that ongoing efforts aimed at achievement of enteral autonomy remain paramount in pediatric intestinal failure.

Translational Research in Pediatrics IV: Solid Tissue Collection and Processing

Solid tissues are critical for child-health research. Specimens are commonly obtained at the time of biopsy/surgery or postmortem. Research tissues can also be obtained at the time of organ retrieval for donation or from tissue that would otherwise have been discarded. Navigating the ethics of solid tissue collection from children is challenging, and optimal handling practices are imperative to maximize tissue quality. Fresh biopsy/surgical specimens can be affected by a variety of factors, including age, gender, BMI, relative humidity, freeze/thaw steps, and tissue fixation solutions. Postmortem tissues are also vulnerable to agonal factors, body storage temperature, and postmortem intervals. Nonoptimal tissue handling practices result in nucleotide degradation, decreased protein stability, artificial posttranslational protein modifications, and altered lipid concentrations. Tissue pH and tryptophan levels are 2 methods to judge the quality of solid tissue collected for research purposes; however, the RNA integrity number, together with analyses of housekeeping genes, is the new standard. A comprehensive clinical data set accompanying all tissue samples is imperative. In this review, we examined: the ethical standards relating to solid tissue procurement from children; potential sources of solid tissues; optimal practices for solid tissue processing, handling, and storage; and reliable markers of solid tissue quality.

Omega-3 Fatty Acid-Rich Parenteral Nutrition: Is It a Double-Edged Sword?

Parenteral nutrition (PN) has been strongly associated with intestinal failure-associated liver disease. Cholestasis, liver steatosis, and liver fibrosis are features of this liver injury, which can progress to end stage liver disease. Omega-3 fatty acid rich PN has been shown to alleviate cholestasis and steatosis. There have been reports although suggesting that it may not be able to arrest or reverse the progression to liver fibrosis. In this article, we develop a hypothesis of the mechanism of how Ω-3 fatty acid rich PN may influence the progression of fibrosis.

The natural history of cirrhosis from parenteral nutrition-associated liver disease after resolution of cholestasis with parenteral fish oil therapy

OBJECTIVE

To determine the natural history of cirrhosis from parenteral nutrition-associated liver disease (PNALD) after resolution of cholestasis with fish oil (FO) therapy.

BACKGROUND

Historically, cirrhosis from PNALD resulted in end-stage liver disease, often requiring transplantation for survival. With FO therapy, most children now experience resolution of cholestasis and rarely progress to end-stage liver disease. However, outcomes for cirrhosis after resolution of cholestasis are unknown and patients continue to be considered for liver/multivisceral transplantation.

METHODS

Prospectively collected data were reviewed for children with cirrhosis because of PNALD who had resolution of cholestasis after treatment with FO from 2004 to 2012. Outcomes evaluated included need for liver/multivisceral transplantation, mortality, and the clinical progression of liver disease.

RESULTS

Fifty-one patients with cirrhosis from PNALD were identified, with 76% demonstrating resolution of cholestasis after FO therapy. The mean direct bilirubin decreased from 6.4 ± 4 mg/dL to 0.2 ± 0.1 mg/dL (P < 0.001) 12 months after resolution of cholestasis, with a mean time to resolution of 74 days. None of the patients required transplantation or died from end-stage liver disease. Pediatric End-Stage Liver Disease scores decreased from 16 ± 4.6 to -1.2 ± 4.6, 12 months after resolution of cholestasis (P < 0.001). In children who remained PN-dependent, the Pediatric End-Stage Liver Disease score remained normal throughout the follow-up period.

CONCLUSIONS

Cirrhosis from PNALD may be stable rather than progressive once cholestasis resolves with FO therapy. Furthermore, these patients may not require transplantation and show no clinical evidence of liver disease progression, even when persistently PN-dependent.

Specific microbiome changes in a mouse model of parenteral nutrition associated liver injury and intestinal inflammation

BACKGROUND

Parenteral nutrition (PN) has been a life-saving treatment in infants intolerant of enteral feedings. However, PN is associated with liver injury (PN Associated Liver Injury: PNALI) in a significant number of PN-dependent infants. We have previously reported a novel PNALI mouse model in which PN infusion combined with intestinal injury results in liver injury. In this model, lipopolysaccharide activation of toll-like receptor 4 signaling, soy oil-derived plant sterols, and pro-inflammatory activation of Kupffer cells (KCs) played key roles. The objective of this study was to explore changes in the intestinal microbiome associated with PNALI.

METHODOLOGY AND PRINCIPAL FINDINGS

Microbiome analysis in the PNALI mouse identified specific alterations within colonic microbiota associated with PNALI and further association of these communities with the lipid composition of the PN solution. Intestinal inflammation or soy oil-based PN infusion alone (in the absence of enteral feeds) caused shifts within the gut microbiota. However, the combination resulted in accumulation of a specific taxon, Erysipelotrichaceae (23.8% vs. 1.7% in saline infused controls), in PNALI mice. Moreover, PNALI was markedly attenuated by enteral antibiotic treatment, which also was associated with significant reduction of Erysipelotrichaceae (0.6%) and a Gram-negative constituent, the S24-7 lineage of Bacteroidetes (53.5% in PNALI vs. 0.8%). Importantly, removal of soy oil based-lipid emulsion from the PN solution resulted in significant reduction of Erysipelotrichaceae as well as attenuation of PNALI. Finally, addition of soy-derived plant sterol (stigmasterol) to fish oil-based PN restored Erysipelotrichaceae abundance and PNALI.

CONCLUSIONS

Soy oil-derived plant sterols and the associated specific bacterial groups in the colonic microbiota are associated with PNALI. Products from these bacteria may directly trigger activation of KCs and promote PNALI. Furthermore, the results indicate that lipid modification of PN solutions may alter specific intestinal bacterial species associated with PNALI, and thus suggest strategies for management of PNALI.

Plasma malondialdehyde levels in children on 12-hour cyclic parenteral nutrition: are there health risks?

In children undergoing total parenteral nutrition (PN), lipids provide a key source of calories preventing or correcting energy deficits and improving outcomes. However, some of these lipids may undergo oxidation leading to the formation of malondialdehyde (MDA), a cytotoxic byproduct found in these patients. This paper aims to describe a sensitive method for detecting MDA and discuss its role in certain diseases commonly found in children on regular PN. To quantify MDA levels in children benefitting from long-term cyclic PN, a reliable and sensitive high-performance liquid chromatographic method based on a 1-step derivatization/extraction procedure analysis with ultraviolet determination at 305 nm wavelength was achieved. In control children without PN, MDA levels were on average 3.30 ± 0.08 µM. However, in children nourished intravenously by fat emulsion for a long time, in which liver problems have been identified, the circulating concentrations of MDA ranged widely at both the start and the end of a session, 3- to 10-fold, respectively, in comparison with the levels measured in controls. This finding indicates that PN administrated long term raises plasma MDA levels, indicating chronic exposure and therefore a possible health risk, particularly liver damage. This preliminary study using a limited number of patients and controls showed that children undergoing long-term PN are strongly exposed to MDA, which must be considered as a potent toxic compound rather than a simple marker of lipid peroxidation.

Liver disease secondary to intestinal failure

IFALD is a common and potentially life-threatening condition for patients with SBS requiring long-term PN. There exists the potential for decreasing its incidence by optimizing the composition and the rate of infusion of parenteral solutions, by advocating a multidisciplinary approach, and by early referral for intestinal-liver transplantation to ensure long-term survival of patients with SBS.

Impact of new-generation lipid emulsions on cellular mechanisms of parenteral nutrition-associated liver disease

Parenteral nutrition (PN) is a life-saving nutritional support for a large population of hospitalized infants, and lipids make a substantial contribution to their energy and essential fatty acid (FA) needs. A challenge in the care of these infants is that their metabolic needs require prolonged PN support that increases the risk of PN-associated liver disease (PNALD). In recent years, the emergence of new parenteral lipid emulsions containing different source lipids and FA profiles has created nutritional alternatives to the first-generation, soybean oil-based lipid emulsion Intralipid. The limited U.S. introduction of the new-generation fish-oil emulsion Omegaven has generated promising results in infants with PNALD and spawned a renewed interest in how PN and lipid emulsions, in particular, contribute to this disease. Studies suggest that the lipid load and constituents, such as specific FAs, ratio of n-3 (ω-3) to n-6 (ω-6) long-chain polyunsaturated FAs, phytosterols, and vitamin E content, may be involved. There is an existing literature describing the molecular mechanisms whereby these specific nutrients affect hepatic metabolism and function via lipid and bile acid sensing nuclear receptors, such as peroxisome proliferator-activated receptor α, liver X receptor, and farnesoid X receptor, yet virtually no information as to how they interact and modulate liver function in the context of PN in pediatric patients or animal models. This article will review the recent development of parenteral lipid emulsions and their influence on PNALD and highlight some of the emerging molecular mechanisms that may explain the effects on liver function and disease.

Total parenteral nutrition-associated cholestasis and risk factors in preterm infants

BACKGROUND/AIM

Development of hepatic dysfunction is a well-recognized complication of total parenteral nutrition in preterm infants. Previous studies reported the incidence of total parenteral nutrition-associated cholestasis and described possible contributing factors to its pathogenesis, but little is done trying to determine its possible predictive risk factors. The aims of this study was to determine the incidence of total parenteral nutrition-associated cholestasis and to develop a possible predictive model for its occurrence.

PATIENTS AND METHODS

A review of medical records of all very low birth weight infants admitted to neonatal intensive care unit at King Khalid University Hospital, Riyadh, Saudi Arabia, between January 2001 and December 2003 was carried out. The infants were divided into two groups: Cholestasis and noncholestasis, based on direct serum bilirubin level >34 μmol/L. A multivariate logistic regression analysis was performed to calculate the statistical significance of risk factors. Receiver-operating characteristic curve was used to determine the optimal cutoff points for the significant risk factors and to calculate their sensitivity and specificity. The level of significance was set at P ≤ 0.05.

RESULTS

A total of 307 patients were included in the analysis. The incidence of cholestasis in the whole population was 24.1% (74 patients). Infants with cholestasis had a lower birth weight, 735.4 ± 166.4 g vs. 1185.0 ± 205.6 g for noncholestasis group (P < 0.001), whereas the mean gestational age for the two groups was 25.4 ± 2.1 week and 28.9 ± 2.1 week, respectively (P < 0.001). The significant risk factors for the development of cholestasis were birth weight (P = 0.006) with an odds ratio of 0.99 [95% confidence interval (CI), 0.98, 0.99]; sensitivity of 92%, specificity of 87%; and total parenteral nutrition duration (P < 0.001) with an odds ratio of 1.18 (95% CI, 1.10, 1.27); sensitivity of 96%, specificity of 89%.

CONCLUSIONS

A lower birth weight and longer duration of total parenteral nutrition were strong predictive risk factors for the development of cholestasis in preterm infants.

Management of short bowel syndrome

Most intestinal failure in children is due to short bowel syndrome (SBS) where congenital or acquired lesions have led to an extensive loss of intestinal mass. The vast majority of morbidity and mortality of patients with SBS is due to complications secondary to their long term dependence on parenteral nutrition. In response to SBS, the intestine undergoes a process of remodeling termed adaptation. Principles guiding the medical management of SBS include providing adequate parenteral nutrition, fluids and electrolytes for growth and normal development, promoting small bowel adaptation, and preventing and treating complications related to the patient's underlying disease and their parenteral nutrition. Catheter associated blood stream infection (CABSI) is major source of morbidity and mortality in patients with intestinal failure from SBS. Intestinal failure associated liver disease (IFALD)is another major source of morbidity and mortality in patients with SBS. IFALD is the most consistent negative predictor of outcome including death and continued parenteral nutrition dependence. Enteral nutrition is critical for intestinal adaptation and preventing IFALD. Patients with SBS who develop dilated dysmotile segments may benefit from autologous intestinal reconstruction surgery (AIRS) with the goal of decreasing stasis and disordered motility through intestinal narrowing and lengthening. Patients with SBS should be referred for transplantation if they have failed intestinal rehabilitation including AIRS, have no reasonable chance for enteral feeding tolerance, develop irreversible IFALD, have recurrent sepsis, or have exhausted their central venous access sites. With improvements in medical and surgical care, overall survival of patients with SBS now exceeds 90%.

Parenteral nutrition-induced cholestasis in neonates: where does the problem lie?

Background. Parenteral nutrition (PN) is an effective method of nourishing the neonate who is unable to receive full enteral feeds. Cholestasis can be a complication of PN and can lead to severe liver damage. Aim. We describe our patient population and determine risk factors for developing PN cholestasis. Methods. Retrospective chart review of newborns admitted from January 2006 to May 2011 to the Neonatal Intensive Care Unit at our institution and received PN >14 days. Cholestasis was defined as serum conjugated bilirubin >50  μ mol/L. Results. Eighty-seven newborns were included; 18 (20.7%) developed PN cholestasis. The most frequent surgical condition for both groups was gastroschisis (8/87; 9.2%). No significant differences were found between the cholestasis and control groups for the following parameters: birth weight, gestational age, intrauterine growth restriction, Apgar scores, and day of life at initiation of enteral feeds. Duration of PN in days and dosage of carbohydrates in g/kg/day were significantly higher in the cholestasis group than the control group. Conclusion. PN-related cholestasis presented in one-fifth of neonates receiving PN for more than two weeks. Longer duration of PN and higher dosage of carbohydrates were independent risk factors for the development of PN cholestasis in this population.

Treatment of parenteral nutrition-associated liver disease: the role of lipid emulsions

Parenteral nutrition is a life-saving therapy for infants with intestinal failure. However, long-term parenteral nutrition carries the risk of progressive liver disease. Substantial data has implicated components of parenteral soybean oil in the pathogenesis of parenteral nutrition-associated liver disease (PNALD). Elevated serum concentrations of phytosterols, an abundance of omega-6 polyunsaturated fatty acids, and a relative paucity of α-tocopherol have been associated with the risk of cholestasis and hepatic injury observed in PNALD. Currently available treatment strategies include the reduction of the dose of administered parenteral soybean oil and/or the replacement of parenteral soybean oil with alternative parenteral lipid emulsions. The purpose of this review is to provide an overview of the pathogenetic mechanisms associated with the development of PNALD and the data evaluating currently available treatment strategies.