Serum plant sterols, cholestanol, and cholesterol precursors associate with histological liver injury in pediatric onset intestinal failure

Lipid Emulsion Type and Liver Function in Parenteral Nutrition Patients: A Retrospective Study of Patients and Prescribing Practices

Parenteral nutrition (PN) is a life-sustaining method to provide adequate nutrients to patients unable to receive oral or enteral nutrition. PN typically contains a mixture of macro- and micro-nutrients, although the lipid composition has been identified as a concern for liver disease. Therefore, the study of the intravenous lipid emulsion (ILE) prescribing practices in home-based PN (HPN) patients and whether differing lipid PN alters liver function tests (LFTs) is needed.

METHODS

A retrospective study of monthly LFTs from a random sample of 105 adult HPN patients in the U.S. over a 6-month period was conducted. Patients were receiving olive oil/soy oil (n = 53, Clinolipid), mixed ILE (n = 39, SMOF Lipid), soy oil (SO; n = 4, Intralipid), or none (n = 7). LFTs monitored were alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (T Bili).

RESULTS

No differences were observed in baseline LFTs across groups (all, p > 0.25, η2 < 0.04), nor were there differences in age, body mass index, days of PN, or mean PN volume (all, p > 0.36, η2 < 0.05). There were no significant interactions between ILE type and time (all p > 0.64, ηp2 < 0.03), no effect of ILE type (all p > 0.60, ηp2 < 0.03), and no effect of time (all p > 0.69, ηp2 < 0.01) in terms of LFTs. Average LFTs over six months were also not different between ILE types (all p > 0.30, η2 < 0.04).

CONCLUSION

These findings suggested that patients were mostly prescribed mixed or ILE PN containing more than one lipid source and that differing ILEs in long-term HPN patients did not alter LFTs over a six-month period.

Featuring molecular regulation of bile acid homeostasis in pediatric short bowel syndrome

BACKGROUND

Disturbed bile acid homeostasis may foster development of short bowel syndrome (SBS) associated liver disease during and after weaning off parenteral nutrition (PN). Our aim was to study hepatic molecular regulation of bile acid homeostasis in relation to serum and fecal bile acid profiles in pediatric SBS.

METHODS

Liver histopathology and mRNA expression of genes regulating synthesis, uptake and export of bile acids, and cellular receptors involved in bile acid signaling were measured in SBS patients (n = 33, median age 3.2 years). Simultaneously, serum (n = 24) and fecal (n = 10) bile acid profiles were assessed. Sixteen patients were currently on PN. Results of patients were compared to healthy control subjects.

RESULTS

Nine of ten (90 %) patients with histological cholestasis received current PN, while portal inflammation was present in 60 % (6/10) of patients with cholestasis compared to 13 % (3/23) without cholestasis (P = 0.01). In all SBS patients, hepatic synthesis and uptake of bile acids was increased. Patients on current PN showed widespread repression of hepatic FXR target genes, including downregulated canalicular (BSEP, MDR3) and basolateral (MRP3) bile acid exporters. Serum and fecal primary bile acids were increased both during and after weaning off PN.

CONCLUSIONS

Bile acid homeostasis in SBS is characterized by interrupted enterohepatic circulation promoting increased hepatic synthesis and conservation of bile acids. In PN dependent SBS patients with hepatic cholestasis and inflammation, the molecular fingerprint of downregulated hepatocyte canalicular and basolateral bile acid export with simultaneously increased synthesis and uptake of bile acids could favor their accumulation in hepatocytes and predispose to liver disease.

Expression of circadian regulatory genes is dysregulated by increased cytokine production in mice subjected to concomitant intestinal injury and parenteral nutrition

BACKGROUND

We have developed a mouse model of Parenteral Nutrition Associated Cholestasis (PNAC) in which combining intestinal inflammation and PN infusion results in cholestasis, hepatic macrophage activation, and transcriptional suppression of bile acid and sterol signaling and transport. In the liver, the master circadian gene regulators Bmal/Arntl and Clock drive circadian modulation of hepatic functions, including bile acid synthesis. Once activated, Bmal and Clock are downregulated by several transcription factors including Reverbα (Nr1d1), Dbp (Dbp), Dec1/2 (Bhlhe40/41), Cry1/2 (Cry1/2) and Per1/2 (Per1/2). The aim of this study was to examine the effects of PN on expression of hepatic circadian rhythm (CR) regulatory genes in mice.

METHODS

WT, IL1KO or TNFRKO mice were exposed to dextran sulfate sodium (DSS) for 4 days followed by soy-oil lipid emulsion-based PN infusion through a central venous catheter for 14 days (DSS-PN) and the expression of key CR regulatory transcription factors evaluated. Animals were NPO on a 14 hr light-dark cycle and were administered PN continuously over 24 hrs. Mice were sacrificed, and hepatic tissue obtained at 9-10AM (Zeitgeber Z+3/Z+4 hrs). PNAC was defined by increased serum aspartate aminotransferase, alanine aminotransferase, total bile acids, and total bilirubin and the effect of i.p. injection of recombinant IL-1β (200ng/mouse) or TNFα (200ng/mouse) on CR expression was examined after 4 hrs.

RESULTS

In the PNAC model, DSS-PN increased serum biomarkers of hepatic injury (ALT, AST, serum bile acids) which was suppressed in both DSS-PN IL1KO and DSS-PN TNFRKO mice. In WT DSS-PN, mRNA expression of Arntl and Dec1 was suppressed corresponding to increased Nr1d1, Per2, Dbp and Dec2. These effects were ameliorated in both DSS-PN IL1KO and DSS-PN TNFRKO groups. Western analysis of the circadian transcription factor network revealed in WT mice DSS-PN significantly suppressed Reverbα, Bmal, Dbp, Per2 and Mtnr1b. With the exception of Dbp, DSS-PN mediated suppression was ameliorated by both IL1KO and TNFRKO. Intraperitoneal injection of IL-1β or TNFα into WT mice increased serum AST and ALT and suppressed mRNA expression of Nr1d1, Arntl and Clock and increased Dbp and Per2.

CONCLUSIONS

Altered expression of CR-dependent regulatory genes during PNAC accompanies cholestasis and is, in part, due to increased cytokine (IL-1β and TNFα) production. Evaluation of the effects of modulating CR in PNAC thus deserves further investigation.

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.

An Overview of Short-Bowel Syndrome in Pediatric Patients: Focus on Clinical Management and Prevention of Complications

Short-bowel syndrome (SBS) in pediatric age is defined as a malabsorptive state, resulting from congenital malformations, significant small intestine surgical resection or disease-associated loss of absorption. SBS is the leading cause of intestinal failure in children and the underlying cause in 50% of patients on home parental nutrition. It is a life-altering and life-threatening disease due to the inability of the residual intestinal function to maintain nutritional homeostasis of protein, fluid, electrolyte or micronutrient without parenteral or enteral supplementation. The use of parenteral nutrition (PN) has improved medical care in SBS, decreasing mortality and improving the overall prognosis. However, the long-term use of PN is associated with the incidence of many complications, including liver disease and catheter-associated malfunction and bloodstream infections (CRBSIs). This manuscript is a narrative review of the current available evidence on the management of SBS in the pediatric population, focusing on prognostic factors and outcome. The literature review showed that in recent years, the standardization of management has demonstrated to improve the quality of life in these complex patients. Moreover, the development of knowledge in clinical practice has led to a reduction in mortality and morbidity. Diagnostic and therapeutic decisions should be made by a multidisciplinary team that includes neonatologists, pediatric surgeons, gastroenterologists, pediatricians, nutritionists and nurses. A significant improvement in prognosis can occur through the careful monitoring of nutritional status, avoiding dependence on PN and favoring an early introduction of enteral nutrition, and through the prevention, diagnosis and aggressive treatment of CRSBIs and SIBO. Multicenter initiatives, such as research consortium or data registries, are mandatory in order to personalize the management of these patients, improve their quality of life and reduce the cost of care.

Pharmacologic inhibition of HNF4α prevents parenteral nutrition associated cholestasis in mice

Prolonged parenteral nutrition (PN) can lead to PN associated cholestasis (PNAC). Intestinally derived lipopolysaccharides and infused PN phytosterols lead to activation of NFκB, a key factor in PNAC. Our objective was to determine if inhibition of HNF4α could interfere with NFκB to alleviate murine PNAC. We showed that HNF4α antagonist BI6015 (20 mg/kg/day) in DSS-PN (oral DSS x4d followed by Total PN x14d) mice prevented the increased AST, ALT, bilirubin and bile acids and reversed mRNA suppression of hepatocyte Abcg5/8, Abcb11, FXR, SHP and MRP2 that were present during PNAC. Further, NFκB phosphorylation in hepatocytes and its binding to LRH-1 and BSEP promoters in liver, which are upregulated in DSS-PN mice, were inhibited by BI6015 treatment. BI6015 also prevented the upregulation in liver macrophages of Adgre1 (F4/80) and Itgam (CD11B) that occurs in DSS-PN mice, with concomitant induction of anti-inflammatory genes (Klf2, Klf4, Clec7a1, Retnla). In conclusion, HNF4α antagonism attenuates PNAC by suppressing NFκB activation and signaling while inducing hepatocyte FXR and LRH-1 and their downstream bile and sterol transporters. These data identify HNF4α antagonism as a potential therapeutic target for prevention and treatment of PNAC.

Potential for Omega-3 Fatty Acids to Protect against the Adverse Effect of Phytosterols: Comparing Laboratory Outcomes in Adult Patients on Home Parenteral Nutrition Including Different Lipid Emulsions

BACKGROUND

the effect on liver function markers and inflammation of the different content of phytosterols in lipid emulsions (LEs) used in the parenteral nutrition (PN) regimen of adult home PN (HPN) patients is not clear.

METHODS

plasma phytosterol and cytokine concentrations, fatty acid composition, liver function markers, and triglycerides were measured in 58 adult HPN patients receiving one of three different LEs (soybean oil-based: Intralipid; olive oil-based: ClinOleic; containing fish oil: SMOFLipid).

RESULTS

patients receiving Intralipid had higher plasma campesterol and stigmasterol concentrations than those receiving ClinOleic or SMOFLipid. Plasma sterol concentrations were not different between patients receiving ClinOleic and SMOFLipid. Differences in plasma fatty acids reflected the fatty acid composition of the LEs. Markers of liver function did not differ among the three groups. Blood triglycerides were higher with ClinOleic than with Intralipid or SMOFLipid. Total bilirubin correlated positively with the plasma concentrations of two of the phytosterols, ALT correlated positively with one, AST with one, and GGT with three.

CONCLUSIONS

liver function markers correlate with plasma plant sterol concentrations in adult HPN patients. Adult HPN patients receiving SMOFLipid are more likely to have liver function markers and triglycerides within the normal range than those receiving ClinOleic or Intralipid. The omega-3 fatty acids in SMOFLipid may act to mitigate the adverse effects of plant sterols on liver function.

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

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.

Interrupting tumor necrosis factor-alpha signaling prevents parenteral nutrition-associated cholestasis in mice

BACKGROUND

We have recently reported a mouse model of PN-associated cholestasis (PNAC) in which combining intestinal inflammation and PN infusion results in cholestasis, hepatic macrophage activation, and transcriptional suppression of canalicular bile acid, bilirubin and sterol transporters Abcb11, Abcc2 and Abcg5/8. The aim of this study was to examine the role of TNFα in promoting PNAC in mice.

METHODS

First, recombinant TNFα was administered to mice as well as in hepatocyte cell culture. Second, Tnfr1/2KO or wild-type (WT) mice were exposed to dextran sulfate sodium (DSS) for 4 days followed by soy-oil lipid emulsion-based PN infusion through a central venous catheter for 14 days (DSS-PN). Finally, WT/DSS-PN mice were also infused with infliximab at 10 mg/kg on days 3 and 10 of PN. PNAC was defined by increased serum aspartate aminotransferase, alanine aminotransferase, total bile acids, and bilirubin.

RESULTS

Intraperitoneal injection of TNFα into WT mice or TNFα treatment of Huh7 hepatocarcinoma cells and primary mouse hepatocytes suppressed messenger RNA (mRNA) transcription of bile (Abcb11, Abcc2]) and sterol transporters (Abcg5/8) and their regulators Nr1h3 and Nr1h4. DSS-PN mice with PNAC had increased hepatic TNFα mRNA expression and significant reduction of mRNA expression of Abcb11, Abcc2, Abcg5/8, Nr1h3, and Nr1h4. In contrast, PNAC development was prevented and mRNA expression normalized in both Tnfr1/2KO /DSS-PN mice and DSS-PN mice treated with infliximab.

CONCLUSIONS

TNFα is a key mediator in the pathogenesis of PNAC through suppression of hepatocyte Abcb11, Abcc2, and Abcg5/8. Pharmacologic targeting of TNFα as a therapeutic strategy for PNAC thus deserves further investigation.

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.

Exploring the long-term risk factors associated with intestinal failure-associated liver disease in pediatric and adult patients: The role of lipid injectable emulsions in the development of liver disease

BACKGROUND

Despite parenteral nutrition (PN) being life sustaining, one of the risk factors associated with its long-term use is intestinal failure-associated liver disease (IFALD), which increases the risk for morbidity and mortality. This review examines some of the risk factors associated with IFALD.

METHODS

A literature review using the databases PubMed, EMBASE, and CINAHL between 2010 and 2020 was performed using search terms, including long-term total PN and liver failure, serum plant sterols and liver failure, and complications and PN. Articles in English using both human and animal participants were included.

RESULTS

The pathophysiology associated with PN and liver disease is multifactorial and influenced by the remaining small-bowel length, presence of the ileal cecal valve, lack of enteral stimulation, type of lipid injectable emulsion (ILE), plant sterol content, and excessive calories. The type of ILE plays a major role because of the phytosterol (PS) content, affecting the microbiome composition and inhibiting key gut signals. The PS content is highest in soy oil (SO)-based ILE, which increases inflammation and impairs biliary flow.

CONCLUSION

Serum PS correlates with liver biomarker abnormalities and is highest in SO-based ILE use compared with mixed-oil emulsions. Selection of a low-PS content ILE is recommended to reduce the risk of biliary cholestasis. Stimulation of the gut, if possible, is recommended to maintain gut integrity and reduce bacterial overgrowth. Fish oil (FO) shows promise in IFALD reversal however, large randomized controlled trials are needed to further establish support for the use of FO in adults.

Role of the Gut Microbiota in Parenteral Nutrition-Associated Liver Disease: From Current Knowledge to Future Opportunities

Parenteral nutrition-associated liver disease (PNALD) refers to a spectrum of conditions that can develop cholestasis, steatosis, fibrosis, and cirrhosis in the setting of parenteral nutrition (PN) use. Patient risk factors include short bowel syndrome, bacterial overgrowth and translocation, disturbance of hepatobiliary circulation, and lack of enteral feeding. A growing body of evidence suggests an intricate linkage between the gut microbiota and the pathogenesis of PNALD. In this review, we highlight current knowledge on the taxonomic and functional changes in the gut microbiota that might serve as noninvasive biomarkers. We also discuss the function of microbial metabolites and associated signaling pathways in the pathogenesis of PNALD. By providing the perspectives of microbiota-host interactions in PNALD for basic and translational research and summarizing current limitations of microbiota-based approaches, this review paves the path for developing novel and precise microbiota-based therapies in PNALD.

Pharmacologic activation of hepatic farnesoid X receptor prevents parenteral nutrition-associated cholestasis in mice

BACKGROUND AND AIMS

Parenteral nutrition (PN)-associated cholestasis (PNAC) complicates the care of patients with intestinal failure. In PNAC, phytosterol containing PN synergizes with intestinal injury and IL-1β derived from activated hepatic macrophages to suppress hepatocyte farnesoid X receptor (FXR) signaling and promote PNAC. We hypothesized that pharmacological activation of FXR would prevent PNAC in a mouse model.

APPROACH AND RESULTS

To induce PNAC, male C57BL/6 mice were subjected to intestinal injury (2% dextran sulfate sodium [DSS] for 4 days) followed by central venous catheterization and 14-day infusion of PN with or without the FXR agonist GW4064. Following sacrifice, hepatocellular injury, inflammation, and biliary and sterol transporter expression were determined. GW4064 (30 mg/kg/day) added to PN on days 4-14 prevented hepatic injury and cholestasis; reversed the suppressed mRNA expression of nuclear receptor subfamily 1, group H, member 4 (Nr1h4)/FXR, ATP-binding cassette subfamily B member 11 (Abcb11)/bile salt export pump, ATP-binding cassette subfamily C member 2 (Abcc2), ATP binding cassette subfamily B member 4(Abcb4), and ATP-binding cassette subfamily G members 5/8(Abcg5/8); and normalized serum bile acids. Chromatin immunoprecipitation of liver showed that GW4064 increased FXR binding to the Abcb11 promoter. Furthermore, GW4064 prevented DSS-PN-induced hepatic macrophage accumulation, hepatic expression of genes associated with macrophage recruitment and activation (ll-1b, C-C motif chemokine receptor 2, integrin subunit alpha M, lymphocyte antigen 6 complex locus C), and hepatic macrophage cytokine transcription in response to lipopolysaccharide in vitro. In primary mouse hepatocytes, GW4064 activated transcription of FXR canonical targets, irrespective of IL-1β exposure. Intestinal inflammation and ileal mRNAs (Nr1h4, Fgf15, and organic solute transporter alpha) were not different among groups, supporting a liver-specific effect of GW4064 in this model.

CONCLUSIONS

GW4064 prevents PNAC in mice through restoration of hepatic FXR signaling, resulting in increased expression of canalicular bile and of sterol and phospholipid transporters and suppression of macrophage recruitment and activation. These data support augmenting FXR activity as a therapeutic strategy to alleviate or prevent PNAC.

Depletion and enrichment of phytosterols in soybean oil lipid emulsions directly associate with serum markers of cholestasis in preterm parenteral nutrition-fed pigs

BACKGROUND

Clinical reports show a positive correlation between phytosterol concentrations and severity of cholestatic liver disease markers in infants during long-term administration of parenteral lipid emulsions. Establishing a causal link between phytosterols and cholestasis has been complicated by confounding factors of lipid emulsion load, fatty acid composition, and vitamin E in many of these studies. The goal of this study is to determine whether altering the phytosterol concentration within a common soybean oil-based emulsion will alter the onset and severity of cholestasis in parenterally fed preterm piglets.

METHODS

Preterm piglets were administered, for 21 days, either enteral nutrition (ENT) or parenteral nutrition (PN) prepared from a soybean oil-based emulsion containing either 24.0% (depleted [DEP]), 100% (Intralipid; normal phytosterol [NP] concentration), or 144% (enriched [ENR]) total phytosterol concentration.

RESULTS

At the end of the study, plasma and liver phytosterol concentrations were highest in the ENR group, followed by NP and then DEP and ENT. Serum direct bilirubin, serum bile acids, and γ-glutamyltransferase were higher in the ENR and NP groups compared with either DEP or ENT groups. All PN lipid groups showed evidence of mild hepatic steatosis but no change in hepatic expression of proinflammatory cytokines or Farnesoid X receptor target genes.

CONCLUSION

The increase in serum direct bilirubin was lower in the DEP group vs the lipid emulsions with normal or ENR phytosterols. Our results provide additional evidence that phytosterols are linked to an increase in serum markers of cholestasis in preterm PN-fed pigs.

ASPEN lipid injectable emulsion safety recommendations part 2: Neonate and pediatric considerations

Lipid injectable emulsions (ILEs) are complex pharmaceutical formulations intended as a source of energy and fatty acids for parenteral nutrition (PN) therapy. Part 1 of this series addressed issues associated with and safety recommendations pertaining to adult ILE use. Part 2 addresses ILE safety in neonatal and pediatric patients. Considerations for ILE use in the neonatal and pediatric populations differ from those of adults. For example, these patients often require higher doses compared with adult counterparts to support growth, development, and daily metabolic needs. ILE is also frequently administered as a separate infusion as opposed to in a total nutrient admixture owing to compatibility and stability issues and limitations to intravenous access in the neonatal and pediatric populations. ILE is the most frequent PN ingredient associated with PN errors occurring in the administration, prescribing, and transcribing processes. Concerns exist with use of in-line filters and repackaging of commercial products for infusion. ILE use in neonatal and pediatric patients has been associated with both minor and major adverse effects, which most often occur with doses exceeding manufacturer recommendations. Gaps in ILE best practices for neonatal and pediatric patients predispose to errors in the PN use system. This paper describes safe-use considerations for ILE products available in the United States in neonatal and pediatric patients, including indications, prescribing, order review, preparation, administration, and monitoring. This paper has been approved by the American Society for Parenteral and Enteral Nutrition (ASPEN) Board of Directors.

Human induced pluripotent stem cell derived hepatocytes provide insights on parenteral nutrition associated cholestasis in the immature liver

Parenteral nutrition-associated cholestasis (PNAC) significantly limits the safety of intravenous parenteral nutrition (PN). Critically ill infants are highly vulnerable to PNAC-related morbidity and mortality, however the impact of hepatic immaturity on PNAC is poorly understood. We examined developmental differences between fetal/infant and adult livers, and used human induced pluripotent stem cell-derived hepatocyte-like cells (iHLC) to gain insights into the contribution of development to altered sterol metabolism and PNAC. We used RNA-sequencing and computational techniques to compare gene expression patterns in human fetal/infant livers, adult liver, and iHLC. We identified distinct gene expression profiles between the human feta/infant livers compared to adult liver, and close resemblance of iHLC to human developing livers. Compared to adult, both developing livers and iHLC had significant downregulation of xenobiotic, bile acid, and fatty acid metabolism; and lower expression of the sterol metabolizing gene ABCG8. When challenged with stigmasterol, a plant sterol found in intravenous soy lipids, lipid accumulation was significantly higher in iHLC compared to adult-derived HepG2 cells. Our findings provide insights into altered bile acid and lipid metabolizing processes in the immature human liver, and support the use of iHLC as a relevant model system of developing liver to study lipid metabolism and PNAC.

Lipid Emulsion Use in Pediatric Patients Requiring Long-Term Parenteral Nutrition

The ability to deliver nutrients via parenteral nutrition (PN) has markedly improved the prognosis of infants and children with intestinal failure. Technical refinements and advances in knowledge have led to the development of highly sophisticated PN solutions that are tailored to meet the needs of pediatric patients. However, children who require long-term PN have an increased risk of complications such as catheter-related sepsis, liver disease, and bone disease. Although the pathogenesis of intestinal failure associated liver disease (IFALD) is multifactorial, studies have identified a possible link between the dose of lipid emulsions based on soybean oil and cholestasis, shown to occur with a significantly higher frequency in patients receiving >1 g lipids/kg/d. Potential contributing factors include oxidative stress, high ω-6 polyunsaturated fatty acid (PUFA) and phytosterol content, and relatively low α-tocopherol levels. Lipid emulsions containing fish oil offer potential advantages compared with traditional emulsions with a high soybean oil content, such as decreased ω-6 and increased ω-3 PUFA concentrations, high concentrations of α-tocopherol, and reduced phytosterol content. Studies in PN-dependent children at risk for IFALD have shown that lipid emulsions containing fish oil reduce the risk of cholestasis and improve biochemical measures of hepatobiliary function compared with pure soybean oil emulsions. This review summarizes evidence regarding the role of lipid emulsions in the management of pediatric patients with intestinal failure requiring long-term PN, with a particular focus on the prevention and treatment of IFALD.

Prediction, identification and progression of histopathological liver disease activity in children with intestinal failure

BACKGROUND & AIMS

Diagnostic criteria, progression risk and optimal monitoring for intestinal failure (IF)-associated liver disease (IFALD) remain undefined. We assessed predictors, non-invasive markers and progression of histopathological liver disease in patients with IF.

METHODS

In total, 77 children with IF and median age of 1.7 years underwent diagnostic liver biopsy, which was repeated in 48 patients after 2.9 years with simultaneous evaluation of liver biochemistry, liver stiffness, serum citrulline (a surrogate for viable enterocyte mass), spleen size, esophageal varices and clinical data. Patients were staged according to histopathological liver disease activity: active IFALD (cholestasis and/or inflammation), chronic IFALD (significant fibrosis and/or steatosis), or no IFALD (none of these features).

RESULTS

Diagnostic liver biopsy revealed active, chronic or no IFALD in 48%, 21% and 31% of patients. Active IFALD was segregated by low serum citrulline, parenteral nutrition (PN) dependency and young age, while weaning off PN and older age predicted chronic IFALD. Although the liver histopathology in most patients either normalized (52%) or transformed to a less reactive (chronic) disease stage (23%), 19% of patients retained and 6.3% progressed to an active cholestatic/inflammatory IFALD phenotype. Decreased serum citrulline and PN-dependency also predicted active IFALD in follow-up biopsies. Increased median liver biochemistry values and liver stiffness only associated with active IFALD, which was accurately identified by gamma-glutamyltransferase (GGT), citrulline and liver stiffness, their combinations reaching diagnostic and follow-up AUROC values above 0.90.

CONCLUSIONS

Active IFALD, essentially predicted by intestinal disruption and PN-dependency, was accurately detected by GGT, liver stiffness and citrulline, which together with recent advances in clinical management options, provides new avenues for monitoring and targeted liver protection in patients with IF.

LAY SUMMARY

Liver disease is a common and critical complication in patients with intestinal failure, who require intravenous nutrition for survival due to severe intestinal dysfunction. We showed that both intravenous nutrition dependency and intestinal disruption essentially predicted development of active histopathological liver disease, which persisted in 25% of patients during long-term follow-up and could be accurately detected without the need for liver biopsy. Identification of the active and potentially progressive histopathology offers new possibilities for monitoring and targeted liver protection in patients with intestinal failure.

Current strategies for managing intestinal failure-associated liver disease

Introduction: Intestinal failure-associated liver disease (IFALD) refers to hepatic dysfunction that results from prolonged parenteral nutrition (PN) use. IFALD is multifactorial in origin and remains a major cause of morbidity and mortality. Prior to 2004, IFALD was associated with mortality as high as 90% in infants who remained on PN greater than 1 year. The advent of new strategies for intravenous lipid emulsion (ILE) administration and improved catheter care now allow many patients to remain on PN and recover from this once fatal condition. Several additional treatment modalities are often used to further improve outcomes for IFALD patients and they are reviewed here.Areas covered: The etiology of IFALD is presented, as well as the rationale behind the use of ILEs that contain fish oil. Other management strategies are addressed, including the effects of several pharmacologic and nutritional interventions.Expert opinion: Like its etiology, the management of IFALD is multifactorial. Prompt recognition of patients at risk, avoiding macronutrient excess, and preventing central line associated bloodstream infections will improve outcomes. In patients who develop IFALD, the use of fish oil monotherapy seems to be efficacious. The most effective intervention, however, continues to be discontinuation of PN and achieving full enteral feedings.

Serum Scoring and Quantitative Magnetic Resonance Imaging in Intestinal Failure-Associated Liver Disease: A Feasibility Study

(1) Background: Intestinal failure-associated liver disease (IFALD) in adults is characterized by steatosis with variable progression to fibrosis/cirrhosis. Reference standard liver biopsy is not feasible for all patients, but non-invasive serological and quantitative MRI markers for diagnosis/monitoring have not been previously validated. Here, we examine the potential of serum scores and feasibility of quantitative MRI used in non-IFALD liver diseases for the diagnosis of IFALD steatosis; (2) Methods: Clinical and biochemical parameters were used to calculate serum scores in patients on home parenteral nutrition (HPN) with/without IFALD steatosis. A sub-group underwent multiparameter quantitative MRI measurements of liver fat fraction, iron content, tissue T1, liver blood flow and small bowel motility; (3) Results: Compared to non-IFALD (n = 12), patients with IFALD steatosis (n = 8) demonstrated serum score elevations in Enhanced Liver Fibrosis (p = 0.032), Aspartate transaminase-to-Platelet Ratio Index (p < 0.001), Fibrosis-4 Index (p = 0.010), Forns Index (p = 0.001), Gamma-glutamyl transferase-to-Platelet Ratio Index (p = 0.002) and Fibrosis Index (p = 0.001). Quantitative MRI scanning was feasible in all 10 sub-group patients. Median liver fat fraction was higher in IFALD steatosis patients (10.9% vs 2.1%, p = 0.032); other parameter differences were non-significant; (4) Conclusion: Serum scores used for non-IFALD liver diseases may be useful in IFALD steatosis. Multiparameter MRI is feasible in patients on HPN.

Phytosterolaemia associated with parenteral nutrition administration in adult patients

Vegetable lipid emulsions (LE) contain non-declared phytosterols (PS). We aimed to determine PS content depending on the brand and LE batch, and in adult hospitalised patients treated with parenteral nutrition (PN), to establish the association between plasma and administered PS. Part I was the LE study: totals and fractions of PS in three to four non-consecutive batches from six LE were analysed. Part II was the patient study: patients with at least 7 previous days of PN with 0·8 g/kg per d of an olive/soyabean (O/S) LE were randomised (day 0) 1:1 to O/S or 100 % fish oil (FO) at a dose of 0·4 g/kg per d for 7 d (day 7). Plasma PS, its fractions, total cholesterol on days 0 and 7, their clearance and their association with PS administered by LE were studied. In part I, LE study: differences were found in the total PS, their fractions and cholesterol among different LE brands and batches. Exclusive soyabean LE had the highest content of PS (422·36 (sd 130·46) μg/ml). In part II, patient study: nineteen patients were included. In the O/S group, PS levels were maintained (1·11 (sd 6·98) μg/ml) from day 0 to 7, while in the FO group, significant decreases were seen in total PS (-6·21 (sd 4·73) μg/ml) and their fractions, except for campesterol and stigmasterol. Plasma PS on day 7 were significantly associated with PS administered (R2 0·443). PS content in different LE brands had great variability. PS administered during PN resulted in accumulation and could be prevented with the exclusive administration of FO LE.

Guidelines for parenteral and enteral nutrition in geriatric patients in China

Based on the expert consensus on parenteral and enteral nutrition support for geriatric patients in China in 2013, domestic multidisciplinary experts were gathered to summarize the new evidence in the field of elderly nutritional support at home and abroad. The 2013 consensus was comprehensively updated and upgraded to a guideline by referring to the World Health Organization (WHO) guidelines for the Grading of Recommendations Assessment, Development, and Evaluation system for grading evidence. These guidelines were divided into two parts: general conditions and common diseases. After discussion by all members of the academic group and consultation with relevant experts, 60 recommendations were ultimately established as standardized nutritional support in the field of geriatrics in China.

Novel Strategies to Prevent Total Parenteral Nutrition-Induced Gut and Liver Inflammation, and Adverse Metabolic Outcomes

Total parenteral nutrition (TPN) is a life-saving therapy administered to millions of patients. However, it is associated with significant adverse effects, namely liver injury, risk of infections, and metabolic derangements. In this review, the underlying causes of TPN-associated adverse effects, specifically gut atrophy, dysbiosis of the intestinal microbiome, leakage of the epithelial barrier with bacterial invasion, and inflammation are first described. The role of the bile acid receptors farnesoid X receptor and Takeda G protein-coupled receptor, of pleiotropic hormones, and growth factors is highlighted, and the mechanisms of insulin resistance, namely the lack of insulinotropic and insulinomimetic signaling of gut-originating incretins as well as the potentially toxicity of phytosterols and pro-inflammatory fatty acids mainly released from soybean oil-based lipid emulsions, are discussed. Finally, novel approaches in the design of next generation lipid delivery systems are proposed. Propositions include modifying the physicochemical properties of lipid emulsions, the use of lipid emulsions generated from sustainable oils with favorable ratios of anti-inflammatory n-3 to pro-inflammatory n-6 fatty acids, beneficial adjuncts to TPN, and concomitant pharmacotherapies to mitigate TPN-associated adverse effects.

MicroRNA 122 Reflects Liver Injury in Children with Intestinal Failure-Associated Liver Disease Treated with Intravenous Fish Oil

BACKGROUND

There is evidence that microRNA (MIR) 122 is a biomarker for various liver diseases in adults and children. To date, MIR122 has not been explored in children with intestinal failure-associated liver disease (IFALD, or hyperbilirubinemia associated with prolonged parenteral nutrition).

OBJECTIVES

This study's purpose was to investigate changes in plasma miR-122, correlate miR-122 with serum liver function tests and enzymes, and investigate changes in whole blood transcripts including miR-122 targets in a group of children with IFALD who received pure intravenous fish oil (FO) as a treatment for cholestasis.

METHODS

This was a prospective, observational study that enrolled children with IFALD who received intravenous FO (1 g/kg/d) and whose cholestasis resolved with FO. Plasma miR-122 was measured using reverse transcription-quantitative real-time PCR, and whole blood miR-122 targets were quantified using RNA sequencing.

RESULTS

Fourteen subjects with median age 6 mo (IQR: 3-65 mo) were enrolled. RNA sequence data were available for 4 subjects. When compared with the start of FO, median miR-122 concentrations at 6 mo of FO therapy decreased [1.0 (IQR: 1.0-1.0) compared with 0.04 (IQR: 0.01-0.6), P = 0.009]. At the start of FO, miR-122 correlated with conjugated bilirubin (r = 0.56; P = 0.038). At ∼3 mo of FO, miR-122 correlated with conjugated bilirubin (r = 0.56; P = 0.045). Reactive oxygen species, heme metabolism, coagulation, adipogenesis, IL-6-Janus kinase-signal transducer and activator of transcription (JAK-STAT) 3, IL-2-STAT5, transforming growth factor-β, TNF-α, inflammatory response, mammalian target of rapamycin gene families (normalized enrichment scores < -1.4), and miR-122 target genes were significantly downregulated with FO.

CONCLUSIONS

In this small cohort of young children with IFALD, miR-122 decreased with FO therapy and correlated with conjugated bilirubin. Key pathways involving oxidation, inflammation, cellular differentiation, and nutrient regulation were downregulated. Data from this study provide information about IFALD and FO. This trial was registered at www.clinicaltrials.gov as NCT00969332.

Parenteral lipids shape gut bile acid pools and microbiota profiles in the prevention of cholestasis in preterm pigs

Multi-component lipid emulsions, rather than soy-oil emulsions, prevent cholestasis by an unknown mechanism. Here, we quantified liver function, bile acid pools, and gut microbial and metabolite profiles in premature parenterally fed pigs given a soy-oil lipid emulsion, Intralipid (IL), a multi component lipid emulsion, SMOFlipid (SMOF), a novel emulsion with a modified fatty-acid composition [experimental emulsion (EXP)], or a control enteral diet (ENT) for 22 days. We assayed serum cholestasis markers, measured total bile acid levels in plasma, liver, and gut contents, and analyzed colonic bacterial 16S rRNA gene sequences and metabolomic profiles. Serum cholestasis markers (i.e., bilirubin, bile acids, and γ-glutamyl transferase) were highest in IL-fed pigs and normalized in those given SMOF, EXP, or ENT. Gut bile acid pools were lowest in the IL treatment and were increased in the SMOF and EXP treatments and comparable to ENT. Multiple bile acids, especially their conjugated forms, were higher in the colon contents of SMOF and EXP than in IL pigs. The colonic microbial communities of SMOF and EXP pigs had lower relative abundance of several gram-positive anaerobes, including Clostridrium XIVa, and higher abundance of Enterobacteriaceae than those of IL and ENT pigs. Differences in lipid and microbial-derived compounds were also observed in colon metabolite profiles. These results indicate that multi-component lipid emulsions prevent cholestasis and restore enterohepatic bile flow in association with gut microbial and metabolomic changes. We conclude that sustained bile flow induced by multi-component lipid emulsions likely exerts a dominant effect in reducing bile acid-sensitive gram-positive bacteria.

New Insights Into Intestinal Failure-Associated Liver Disease in Children

Development of intestinal failure-associated liver disease (IFALD) is a common complication of long-term parenteral nutrition (PN) in children and adults. The molecular and cellular mechanisms and the phases of IFALD are now being delineated. Components of PN lipid emulsions, including plant sterols, interact with hepatic innate immune activation promoted by products of gut bacterial overgrowth/dysbiosis and altered intestinal barrier function (gut-liver axis) and by episodes of sepsis to cause cholestasis and IFALD. New therapeutic strategies, including modifications of intravenous lipid emulsions to reduce pro-inflammatory fatty acids and plant sterol content, can lower the risk of IFALD, reverse cholestasis, and reduce complications, although the significance of persisting hepatic fibrosis is unknown. This review will provide an update on advances in the pathogenesis of IFALD, newer therapeutic and preventative strategies, and challenges that confront managing patients with IFALD.

Cardiovascular Disease Prevention: The Earlier the Better? A Review of Plant Sterol Metabolism and Implications of Childhood Supplementation

Atherosclerosis is the underlying cause of major cardiovascular events. The development of atherosclerotic plaques begins early in life, indicating that dietary interventions in childhood might be more effective at preventing cardiovascular disease (CVD) than treating established CVD in adulthood. Although plant sterols are considered safe and consistently effective in lowering plasma cholesterol, the health effects of early-life supplementation are unclear. Studies suggest there is an age-dependent effect on plant sterol metabolism: at a younger age, plant sterol absorption might be increased, while esterification and elimination might be decreased. Worryingly, the introduction of low-cholesterol diets in childhood may unintentionally favor a higher intake of plant sterols. Although CVD prevention should start as early as possible, more studies are needed to better elucidate the long-term effects of plant sterol accumulation and its implication on child development.

The evolving use of intravenous lipid emulsions in the neonatal intensive care unit

Parenteral nutrition and intravenous lipid emulsions are essential for promoting optimal nutrition in the neonatal intensive care unit. However, long-term use of a pure soybean lipid emulsion is associated with a liver disease known as intestinal failure associated liver disease. Over the past several years, the science of lipid emulsions has evolved with a focus on nutritional optimization and disease prevention. This review's purpose is to provide a general overview of the three main components of lipid emulsions, phytosterols, the antioxidant Vitamin E, and polyunsaturated fatty acids, and their contribution to health.

A Retrospective Analysis of the Effect of Combination of Pure Fish Oil with Third Generation Lipid Emulsion on Liver Function in Children on Long-Term Parenteral Nutrition

BACKGROUND

Deterioration of liver function, or intestinal failure-associated liver disease, is often observed in long-term parenterally fed children. Fish oil-based intravenous lipids have been reported to play a role in the prevention and treatment of intestinal failure associated liver disease.

METHODS

This retrospective analysis included 40 pediatric patients, (20 male and 20 female), median age 38 months (range 1.5-200 months) on long-term (≥1 month) parenteral nutrition who received the parenteral mixtures containing a combination of a third-generation lipid emulsion and pure fish oil because of laboratory liver function abnormalities. The total dose of fish oil from both emulsions for each patient exceeded 0.5 g/kg/day. Data from visits in an outpatient clinic were retrospectively analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation test.

RESULTS

The median time of therapy was 149 days (range 28-418 days). There was a decrease of median total and direct (conjugated) bilirubin concentration from 22.23 µmol/L (range 3.42-243 µmol/L) to 10.26 µmol/L (range 3.42-180.58 µmol/L; p < 0.005) and 8.55 (range 1.71-212.04 µmol/L) to 6.84 µmol/L (range 1.71-150.48 µmol/L; p < 0.007) respectively. A significant decrease in median alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase was also observed. In 11 patients bilirubin concentrations increased or remained unchanged. When compared to the patients who responded to the combination therapy, the patients who did not respond received parenteral nutrition for a longer time prior to the start of the therapy (51 vs. 30 months; p < 0.05).

CONCLUSIONS

The mixture of an intravenous lipid emulsion containing soybean oil, medium-chain triglycerides, olive oil, and fish oil with the addition of pure fish oil emulsion may be helpful in the treatment of liver complications in children on long-term parenteral nutrition.

Progress and perspectives in plant sterol and plant stanol research

Current evidence indicates that foods with added plant sterols or stanols can lower serum levels of low-density lipoprotein cholesterol. This review summarizes the recent findings and deliberations of 31 experts in the field who participated in a scientific meeting in Winnipeg, Canada, on the health effects of plant sterols and stanols. Participants discussed issues including, but not limited to, the health benefits of plant sterols and stanols beyond cholesterol lowering, the role of plant sterols and stanols as adjuncts to diet and drugs, and the challenges involved in measuring plant sterols and stanols in biological samples. Variations in interindividual responses to plant sterols and stanols, as well as the personalization of lipid-lowering therapies, were addressed. Finally, the clinical aspects and treatment of sitosterolemia were reviewed. Although plant sterols and stanols continue to offer an efficacious and convenient dietary approach to cholesterol management, long-term clinical trials investigating the endpoints of cardiovascular disease are still lacking.

Liver Inflammation Relates to Decreased Canalicular Bile Transporter Expression in Pediatric Onset Intestinal Failure

OBJECTIVE

Although liver disease is a major complication of parenteral nutrition (PN) for intestinal failure (IF), its pathogenesis remains unclear. We investigated potential molecular mechanisms of liver injury in pediatric onset IF.

METHODS

Liver expression of canalicular phospholipid (ABCB4), bile acid (ABCB11), and sterol (ABCG5/8) transporters, their upstream regulators LXR and FXR as well as pro-inflammatory cytokines interleukin-6 (IL6) and tumor necrosis factor (TNF) were investigated among patients with IF [age median 3.8 (IQR 1.2 to 11)] in relation to biochemical and histologic liver injury, PN, serum plant sterols, fibroblast growth factor 19, and α-tocopherol.

RESULTS

Patients receiving PN currently (n = 18) showed more advanced liver injury than patients after weaning off PN (n = 30). Histologic portal inflammation strongly segregated PN-dependent (44%) from weaned off patients (3%, P = 0.001) and coupled with progression of cholestasis and liver fibrosis. Patients with portal inflammation demonstrated markedly induced liver RNA expression of IL6 and TNF, repression of FXR and its canalicular bile transporter target gene RNA expression, including ABCB4 and ABCB11 as well as decreased protein expression of ABCB11 and ABCB4. Furthermore, upregulation of LXR and ABCG5/8 RNA expression was suppressed in patients with portal inflammation. Current PN, increased serum levels of plant sterols stigmasterol, avenasterol, and sitosterol along with serum citrulline, a marker of enterocyte mass, predicted portal inflammation.

CONCLUSIONS

In pediatric onset IF, current PN delivery synergistically with intestinal compromise promote liver inflammation, which associates with progression of biochemical and histologic liver injury, while reducing expression of canalicular bile transporters.

Non-Cholesterol Sterol Concentrations as Biomarkers for Cholesterol Absorption and Synthesis in Different Metabolic Disorders: A Systematic Review

Non-cholesterol sterols are validated biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis. However, their use in metabolic disturbances has not been systematically explored. Therefore, we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders. Potentially relevant studies were retrieved by a systematic search of three databases in July 2018 and ninety-four human studies were included. Cholesterol-standardized levels of campesterol, sitosterol and cholestanol were collected to reflect cholesterol absorption and those of lathosterol and desmosterol to reflect cholesterol synthesis. Their use as biomarkers was examined in the following metabolic disorders: overweight/obesity (n = 16), diabetes mellitus (n = 15), metabolic syndrome (n = 5), hyperlipidemia (n = 11), cardiovascular disease (n = 17), and diseases related to intestine (n = 16), liver (n = 22) or kidney (n = 2). In general, markers for cholesterol absorption and synthesis displayed reciprocal patterns, showing that cholesterol metabolism is tightly regulated by the interplay of intestinal absorption and endogenous synthesis. Distinctive patterns for cholesterol absorption or cholesterol synthesis could be identified, suggesting that metabolic disorders can be classified as 'cholesterol absorbers or cholesterol synthesizers'. Future studies should be performed to confirm or refute these findings and to examine whether this information can be used for targeted (dietary) interventions.

Plasma Phytosterol Half-Life and Levels Are Increased in Very Low Birth Weight Preterm Infants with Parenteral Nutrition-Associated Cholestasis

Parenteral nutrition-associated cholestasis (PNAC) has been linked to plasma accumulation of phytosterols in infants receiving vegetable-oil-based lipid emulsions (LE). To date, information on the ability of infants with PNAC to metabolize intravenous (IV) phytosterols has been very limited. We characterized plasma phytosterol half-life in very low birth weight (VLBW) preterm infants with PNAC. As part of a prospective cohort study, VLBW infants with PNAC underwent serial blood sample measurements of sitosterol (Sito), campesterol (Camp), and stigmasterol (Stigma). Infants without PNAC served as controls (CTRL, control infants). Thirty-seven PNAC infants and 14 CTRL were studied. On PN day 7 and PN day 14, PNAC infants had higher plasma phytosterol concentrations compared to those of CTRL (p < 0.05). A significant and positive correlation was found between plasma Camp, Stigma, Sito concentrations, and IV phytosterol intake from birth to PN day 7 (p = 0.001, p = 0.001, and p = 0.005, respectively). Stigma concentration was positively correlated with conjugated bilirubin on PN day 7 (p = 0.012). After stopping IV LE, half-lives of Camp, Stigma, and Sito became significantly longer in PNAC infants than in CTRL (Camp: 18.8 ±6.2 vs 11.8 ±3.0 days, p = 0.001; Stigma: 13.8 ±5.8 vs 9.4 ±3.4 days, p = 0.023; Sito: 15.3 ±5.0 vs 9.8 ±3.0 days, p = 0.002). In conclusion, phytosterols increased earlier during PN and were eliminated slowly after stopping IV LE in PNAC infants than in CTRL. The Stigma concentration on PN day 7 could represent an early marker of cholestasis. Our results provide additional evidence on the relationship between IV phytosterols and PNAC.

Prevention and Treatment of Intestinal Failure-Associated Liver Disease in Children

Intestinal failure-associated liver disease (IFALD) is a threatening complication for children on long-term parenteral nutrition because of intestinal failure. When progressive and intractable, it may jeopardize intestinal rehabilitation and lead to combined liver and intestinal transplantation. The institution of dedicated intestinal failure centers has dramatically decreased the incidence of such complication. IFALD may rapidly fade away if very early management aimed at preventing progression to end-stage liver disease is provided. In this review, we address the etiology and risk factors of IFALD in order to introduce pillars of prevention (nutritional management and catheter-related infections control). The latest evidence of therapeutic strategies, such as medical and surgical treatments, is also discussed.

Macrophage-derived IL-1β/NF-κB signaling mediates parenteral nutrition-associated cholestasis

In infants intolerant of enteral feeding because of intestinal disease, parenteral nutrition may be associated with cholestasis, which can progress to end-stage liver disease. Here we show the function of hepatic macrophages and phytosterols in parenteral nutrition-associated cholestasis (PNAC) pathogenesis using a mouse model that recapitulates the human pathophysiology and combines intestinal injury with parenteral nutrition. We combine genetic, molecular, and pharmacological approaches to identify an essential function of hepatic macrophages and IL-1β in PNAC. Pharmacological antagonism of  IL-1 signaling or genetic deficiency in CCR2, caspase-1 and caspase-11, or IL-1 receptor (which binds both IL-1α and IL-1β) prevents PNAC in mice. IL-1β increases hepatocyte NF-κB signaling, which interferes with farnesoid X receptor and liver X receptor bonding to respective promoters of canalicular bile and sterol transporter genes (Abcc2, Abcb11, and Abcg5/8), resulting in transcriptional suppression and subsequent cholestasis. Thus, hepatic macrophages, IL-1β, or NF-κB may be targets for restoring bile and sterol transport to treat PNAC.

Intravenous Fish Oil and Pediatric Intestinal Failure-Associated Liver Disease: Changes in Plasma Phytosterols, Cytokines, and Bile Acids and Erythrocyte Fatty Acids

BACKGROUND

Soybean oil (SO) emulsions are associated with intestinal failure-associated liver disease (IFALD); fish oil (FO) emulsions are used to treat IFALD. SO and FO differ with respect to their fatty acid and phytosterol content. In children with IFALD whose SO was replaced with FO, we aimed to (1) quantify changes in erythrocyte fatty acids and plasma phytosterols, cytokines, and bile acids and (2) correlate these changes with direct bilirubin (DB).

DESIGN

This study enrolled IFALD children who received 6 months of FO. Blood samples were collected prior to FO, and after 2 weeks and 3 and 6 months of FO. The primary outcome was 3-month vs baseline biomarker concentrations.

RESULTS

At study initiation, the median patient age was 3 months (interquartile range, 3-17 months), and mean ± standard deviation DB was 5.6 ± 0.7 mg/dL (n = 14). Cholestasis reversed in 79% of subjects. Eicosapentaenoic and docosahexaenoic acid was greater than baseline (P < .001, all time points). Linoleic and arachidonic acid and sitosterol and stigmasterol were less than baseline (P < .05, all time points). Three- and 6-month interleukin-8 (IL-8) and total and conjugated bile acids were less than baseline (P < .05). Baseline IL-8 was correlated with baseline DB (r = 0.71, P < .01). Early changes in stigmasterol and IL-8 were correlated with later DB changes (r = 0.68 and 0.75, P < .05).

CONCLUSION

Specific fat emulsion components may play a role in IFALD. Stigmasterol and IL-8 may predict FO treatment response.

Low-Dose Parenteral Soybean Oil for the Prevention of Parenteral Nutrition-Associated Liver Disease in Neonates With Gastrointestinal Disorders

BACKGROUND

Neonates with gastrointestinal disorders (GDs) are at high risk for parenteral nutrition-associated liver disease (PNALD). Soybean-based intravenous lipid emulsions (S-ILE) have been associated with PNALD. This study's objective was to determine if a lower dose compared with a higher dose of S-ILE prevents cholestasis without compromising growth.

MATERIALS AND METHODS

This multicenter randomized controlled pilot study enrolled patients with GDs who were ≤5 days of age to a low dose (~1 g/kg/d) (LOW) or control dose of S-ILE (~3 g/kg/d) (CON). The primary outcome was cholestasis (direct bilirubin [DB] >2 mg/dL) after the first 7 days of age. Secondary outcomes included growth, PN duration, and late-onset sepsis.

RESULTS

Baseline characteristics were similar between the LOW (n = 20) and CON groups (n = 16). When the LOW group was compared with the CON group, there was no difference in cholestasis (30% vs 38%, P = .7) or secondary outcomes. However, mean ± SE DB rate of change over the first 8 weeks (0.07 ± 0.04 vs 0.3 ± 0.09 mg/dL/wk, P = .01) and entire study (0.008 ± 0.03 vs 0.2 ± 0.07 mg/dL/wk, P = .02) was lower in the LOW group compared with the CON group.

CONCLUSION

In neonates with GDs who received a lower dose of S-ILE, DB increased at a slower rate in comparison to neonates who received a higher dose of S-ILE. Growth was comparable between the groups. This study demonstrates a need for a larger, randomized controlled trial comparing 2 different S-ILE doses for cholestasis prevention in neonates at risk for PNALD.

Transient elastography and aspartate aminotransferase to platelet ratio predict liver injury in paediatric intestinal failure

BACKGROUND & AIMS

We aimed to evaluate the value of AST to platelet ratio (APRI) and transient elastography (TE) as predictors of liver histopathology in children with intestinal failure (IF).

METHODS

Altogether 93 liver biopsies from 57 children with parenteral nutrition (PN) duration ≥3 months were analysed. APRI measurement and TE (n = 46) were performed at the time of biopsy.

RESULTS

IF was caused by short bowel syndrome in 75% of patients. At the time of liver biopsy, PN dependent patients (n = 42) were younger with longer PN duration compared to those weaned off PN (n = 51) (2.2 vs. 7.6 years, P < 0.001; 26 vs. 10.5 months, P = 0.043). Elevated transaminase or bilirubin levels were found in 51%, splenomegaly in 26%, and oesophageal varices in 3.5%. Histological fibrosis was present in 61% (Metavir stage F1; 27%, F2; 26%, F3-4; 9%), cholestasis in 25% and steatosis in 22% of biopsy specimens. TE was superior to APRI in prediction of any liver histopathology (fibrosis, cholestasis or steatosis) with areas under the receiving operating curve (AUROC) of 0.86 (95% CI 0.74-0.97) and 0.67 (95% CI 0.58-0.78) respectively. For prediction of ≥F1 and ≥F2 fibrosis, AUROC values for TE were 0.78 (95% CI 0.64-0.93) and 0.73 (95% CI 0.59-0.88), whereas APRI did not correlate with fibrosis stages. For detection of histological cholestasis, the AUROC for APRI was 0.77 (95% CI 0.64-0.89).

CONCLUSIONS

Both TE and APRI are promising noninvasive methods for monitoring the development of IF-related liver histopathology. TE values reflected the degree of fibrosis better while APRI detected histological cholestasis more accurately.

Total Parenteral Nutrition-Induced Cholestasis: Prevention and Management

When cholestasis occurs in patients receiving total parenteral nutrition, it is the result of many pathogenic pathways converging on the hepatic acinus. The result may be a temporary rise in liver function tests. The resulting fibrosis, portal hypertension, and jaundice are hallmarks of type 3 intestinal-associated liver disease to which children are more susceptible than adults. The key to prevention is in identifying high-risk scenarios, meticulous monitoring, and personalized prescription of parenteral nutrition solutions combined with an active approach in reducing the impact of inflammatory events when they occur by prompt use of antibiotics and line locks.

Intravenous Lipid Emulsions in Parenteral Nutrition

Fat is an important macronutrient in the human diet. For patients with intestinal failure who are unable to absorb nutrients via the enteral route, intravenous lipid emulsions play a critical role in providing an energy-dense source of calories and supplying the essential fatty acids that cannot be endogenously synthesized. Over the last 50 y, lipid emulsions have been an important component of parenteral nutrition (PN), and over the last 10-15 y many new lipid emulsions have been manufactured with the goal of improving safety and efficacy profiles and achieving physiologically optimal formulations. The purpose of this review is to provide a background on the components of lipid emulsions, their role in PN, and to discuss the lipid emulsions available for intravenous use. Finally, the role of parenteral fat emulsions in the pathogenesis and management of PN-associated liver disease in PN-dependent pediatric patients is reviewed.

Loss of ileum decreases serum fibroblast growth factor 19 in relation to liver inflammation and fibrosis in pediatric onset intestinal failure

BACKGROUND & AIMS

The pathogenesis of intestinal failure (IF) associated liver disease (IFALD) is uncertain, we therefore investigated the role of FGF19 and pro-inflammatory cytokines has on this disease state.

METHODS

Serum FGF19, IL-6 and, TNF-α were measured in 52 IF patients at median age 6.0 years (IQR 2.2-13) after 10 months (4.1-39) on parenteral nutrition (PN). Thirty-nine patients underwent liver biopsies.

RESULTS

In IF patients, FGF19 concentrations were lower and those of IL-6 and TNF-α higher compared to healthy matched controls (p ⩽ 0.001 for all). FGF19 concentrations were further decreased in patients without a remaining ileum [37 pg/ml (IQR 30-68) vs. 74 (35-135) p=0.028], and correlated with remaining ileum length (r = 0.333, p = 0.018) and markers of cholesterol synthesis (r = -0.552 to -0.643, p < 0.001). Patients with histological portal inflammation [30 pg/ml (28-45) vs. 48 (33-100), p = 0.019] or fibrosis [35 pg/ml (30-66) vs. 99 (38-163), p = 0.013] had lower serum FGF19 concentrations than others. FGF19 negatively correlated with portal inflammation grade (r = -0.442, p = 0.005), serum TNF-α (r = -0.318, p = 0.025), METAVIR fibrosis stage (r = -0.441, p = 0.005) and APRI (r = -0.328, p = 0.028). IL-6 was higher during PN [6 pg/ml (2-31)] than after weaning off PN [2 pg/ml (1-5), p = 0.009], correlated weakly with cholestasis grade (r = 0.328, p = 0.044), and tended to associate with histological cholestasis [n = 5, 5 pg/ml (5-267) vs. n=34, 2 pg/ml (1-7), p = 0.058].

CONCLUSIONS

In pediatric onset of IF, total or partial loss of ileum decreases serum FGF19 concentration corresponding to hepatic inflammation and fibrosis, along with increased cholesterol synthesis. In contrast, serum IL-6 increases during PN and may associate with concurrent cholestasis. These data suggests that FGF19 may contribute to the pathogenesis of IFALD.

Autologous intestinal reconstruction surgery as part of comprehensive management of intestinal failure

Pediatric intestinal failure (IF) remains to be associated with significant morbidity and mortality, the most frequent underlying etiologies being short bowel syndrome (SBS), and primary motility disorders. Management aims to assure growth and development, while preventing complications and facilitating weaning off parenteral support (PS) by fully utilizing adaptation potential of the remaining gut. Probability of survival and weaning off PS is improved by coordinated multidisciplinary intestinal rehabilitation combining individualized physiological enteral and parenteral nutrition (PN), meticulous central line care and medical management with carefully planned surgical care. Increasing evidence suggests that autologous intestinal reconstruction (AIR) surgery is effective treatment for selected short bowel patients. Bowel lengthening procedures normalize pathological adaptation-associated short bowel dilatation with potential to support intestinal absorption and liver function by various mechanisms. Although reversed small intestinal segment, designed to prolong accelerated intestinal transit, improves absorption in adult SBS, its feasibility in children remains unclear. Controlled bowel obstruction to induce dilatation followed by bowel lengthening aims to gain extra length in patients with the shortest duodenojejunal remnant. Reduced PS requirement limits the extent of complications, improving prognosis and quality of life. The great majority of children with SBS can be weaned from PS while prognosis of intractable primary motility disorders remains poor without intestinal transplantation, which serves as a salvage therapy for life-threatening complications such as liver failure, central vein thrombosis or recurrent bloodstream infections.

Vitamin E in New-Generation Lipid Emulsions Protects Against Parenteral Nutrition-Associated Liver Disease in Parenteral Nutrition-Fed Preterm Pigs

INTRODUCTION

Parenteral nutrition (PN) in preterm infants leads to PN-associated liver disease (PNALD). PNALD has been linked to serum accumulation of phytosterols that are abundant in plant oil but absent in fish oil emulsions.

HYPOTHESIS

Whether modifying the phytosterol and vitamin E composition of soy and fish oil lipid emulsions affects development of PNALD in preterm pigs.

METHODS

We measured markers of PNALD in preterm pigs that received 14 days of PN that included 1 of the following: (1) Intralipid (IL, 100% soybean oil), (2) Intralipid + vitamin E (ILE, d-α-tocopherol), (3) Omegaven (OV, 100% fish oil), or (4) Omegaven + phytosterols (PS, β-sitosterol, campesterol, and stigmasterol).

RESULTS

Serum levels of direct bilirubin, gamma glutamyl transferase, serum triglyceride, low-density lipoprotein, and hepatic triglyceride content were significantly lower (P < .05) in the ILE, OV, and PS compared to IL. Hepatic cholesterol 7-hydroxylase and organic solute transporter-α expression was lower (P < .05) and portal plasma FGF19 higher in the ILE, OV, and PS vs IL. Hepatic expression of mitochondrial carnitine palmitoyltransferase 1A and microsomal cytochrome P450 2E1 fatty acid oxidation genes was higher in ILE, OV, and PS vs IL. In vivo (13)C-CDCA clearance and expression of pregnane X receptor target genes, cytochrome P450 3A29 and multidrug resistance-associated protein 2, were higher in ILE, OV, and PS vs IL.

CONCLUSIONS

α-tocopherol in Omegaven and added to Intralipid prevented serum and liver increases in biliary and lipidemic markers of PNALD in preterm piglets. The addition of phytosterols to Omegaven did not produce evidence of PNALD.