The role of parenteral lipids in the development of advanced intestinal failure-associated liver disease in infants: a multiple-variable analysis

From intestinal failure to transplantation: Review on the current need for transplant indications under multidisciplinary transplant programs worldwide

INTRODUCTION

Intestinal failure, defined as the loss of gastrointestinal function to the point where nutrition cannot be maintained by enteral intake alone, presents numerous challenges in children, not least the timing of consideration of intestine transplantation.

OBJECTIVES

To describe the evolution of care of infants and children with intestinal failure including parenteral nutrition, intestine transplantation, and contemporary intestinal failure care.

METHODS

The review is based on the authors' experience supported by an in-depth review of the published literature.

RESULTS

The history of parenteral nutrition, including out-patient (home) administration, and intestine transplantation are reviewed along with the complications of intestinal failure that may become indications for consideration of intestine transplantation. Current management strategies for children with intestinal failure are discussed along with changes in need for intestine transplantation, recognizing the difficulty in generalizing recommendations due to the high level of heterogeneity of intestinal pathology and residual bowel anatomy and function.

DISCUSSION

Advances in the medical and surgical care of children with intestinal failure have resulted in improved transplant-free survival and a significant fall in demand for transplantation. Despite these improvements a number of children continue to fail rehabilitative care and require intestine transplantation as life-saving therapy or when the burden on ongoing parenteral nutrition becomes too great to bear.

Parenteral nutrition-associated liver injury: clinical relevance and mechanistic insights

Intestinal failure-associated liver disease (IFALD) is a relatively common complication in individuals receiving parenteral nutrition (PN). IFALD can be manifested as different types of liver injury, including steatosis, cholestasis, and fibrosis, and could result in liver failure in some cases. The onset and progression of IFALD are highly dependent on various patient and PN-related risk factors. Despite still being under investigation, several mechanisms have been proposed. Liver injury can originate due to caloric overload, nutrient deficiency, and toxicity, as well as phytosterol content, and omega-6 to omega-3 fatty acids ratio contained in lipid emulsions. Additional mechanisms include immature or defective bile acid metabolism, acute heart failure, infections, and sepsis exerting negative effects via Toll-like receptor 4 and nuclear factor κB inflammatory signaling. Furthermore, lack of enteral feeding, gut dysbiosis, and altered enterohepatic circulation that affect the farnesoid x receptor-fibroblast growth factor 19 axis can also contribute to IFALD. Various best practices can be adopted to minimize the risk of developing IFALD, such as prevention and management of central line infections and sepsis, preservation of intestine's length, a switch to oral and enteral feeding, cyclic PN, avoidance of overfeeding and soybean oil-based lipid formulations, and avoiding hepatotoxic substances. The present review thus provides a comprehensive overview of all relevant aspects inherent to IFALD. Further research focused on clinical observations, translational models, and advanced toxicological knowledge frameworks is needed to gain more insight into the molecular pathogenesis of hepatotoxicity, reduce IFALD incidence, and encourage the safe use of PN.

Cost-utility analysis of 4% tetrasodium ethylenediaminetetraacetic acid, taurolidine, and heparin lock to prevent central line-associated bloodstream infections in children with intestinal failure

BACKGROUND

Central line-associated bloodstream infections (CLABSI) are a serious complication in children with intestinal failure. This study assessed the incremental costs of 4% tetrasodium ethylenediaminetetraacetic acid (EDTA) compared with taurolidine lock and heparin lock per quality-adjusted life-year (QALY) gained in children with intestinal failure from the healthcare payer and societal perspective.

METHODS

A Markov cohort model of a 1-year-old child with intestinal failure was simulated until the age of 17 years (time horizon), with a cycle length of 1 month. The health outcome measure was QALYs, with results expressed in terms of incremental costs and QALYs. Model parameters were obtained from published literature and institutional data. Deterministic, probabilistic, and scenario sensitivity analyses were performed.

RESULTS

4% Tetrasodium EDTA was dominant (more effective and less expensive) compared with taurolidine and heparin, yielding an additional 0.17 QALYs with savings of CAD$88,277 compared with heparin, and an additional 0.06 QALYs with savings of CAD$52,120 compared with taurolidine lock from the healthcare payer perspective. From the societal perspective, 4% tetrasodium EDTA resulted in savings of CAD$90,696 compared with heparin and savings of CAD$36,973 compared with taurolidine lock.

CONCLUSIONS

This model-based analysis indicates that 4% tetrasodium EDTA can be considered the optimal strategy compared with taurolidine and heparin in terms of cost-effectiveness. The decision uncertainty can be reduced by conducting further research on the model input parameters. An expected value of perfect information analysis can identify what model input parameters would be most valuable to focus on.

Cost-utility analysis of teduglutide compared to standard care in weaning parenteral nutrition support in children with short bowel syndrome

BACKGROUND & AIMS

A growing proportion of children with short bowel syndrome (SBS) remain dependent on long-term parenteral nutrition (PN). Teduglutide offers the potential for more children to decrease PN support and achieve enteral autonomy (EA), but at a significant expense. This study aims to assess the incremental costs of teduglutide plus standard of care compared to standard of care alone in weaning PN support per quality-adjusted life year (QALY) gained in children with SBS.

METHODS

This is a cost-utility analysis comparing teduglutide with standard of care alone in children with SBS. A microsimulation model of children with SBS on PN aged 1-17 years was constructed over a time horizon of six years, with a cycle length of one month. The study adopted the healthcare system and societal payer perspectives in Ontario, Canada. The health outcome measure was QALYs, with results expressed in terms of incremental costs and QALYs. Scenario analyses were performed to examine the effects of different time horizons, timing of teduglutide initiation, and modeling cost of teduglutide based on pediatric weight-dosing.

RESULTS

Incremental healthcare system costs for teduglutide compared to standard of care were CAD$441,314 (95% CI, 414,006 to 441,314) and incremental QALYs were 1.80 (95% CI, 1.70 to 1.89) resulting in an incremental cost-effectiveness ratio (ICER) of CAD$285,334 (95% CI, 178,209 to 392,459) per QALY gained. Incremental societal costs were CAD$418,504 (95% CI, 409,487 to 427,522) and incremental societal QALYs were 1.91 (95% CI, 1.85 to 1.98) resulting in an ICER of CAD$261,880 (95% CI, 136,887 to 386,874) per QALY gained. Scenario analysis showed that teduglutide was cost-effective when it was started two years after intestinal resection (ICER CAD$48,741, 95% CI, 17,317 to 80,165) and when its monthly cost was adjusted using weight-based dosing, avoiding wastage of the remaining 5 mg dose vial (Teduglutide dominated over SOC as the less costly and most effective strategy).

CONCLUSIONS

Although teduglutide was not cost-effective in weaning PN support in children with SBS, starting teduglutide once natural intestinal adaptation is reduced and adjusting its monthly cost to reflect cost by volume as dictated by weight-based dosing rendered the intervention cost-effective relative to standard of care. These results indicate the potential for clinicians to re-assess optimal time for initiation of teduglutide after intestinal resection, drug manufacturers to consider the use of multi-dose or paediatric-dose vials, and the opportunity for decision-makers to re-evaluate teduglutide funding.

In parenteral nutrition-fed piglets, fatty acids vary by lipid emulsion and tissue sampled

BACKGROUND

Children with intestinal failure without liver disease may be given soy-based lipid emulsion (SLE) or mixed lipid emulsion (MLE; containing soy, medium-chain triglyceride, olive, and/or fish oils). Both differ in essential fatty acid content: MLE has added arachidonic acid (AA) and docosahexaenoic acid (DHA). The aim of this study, in neonatal piglets, was to compare serum and tissue fatty acid composition when the emulsions were given at unrestricted doses.

METHODS

We compared SLE (n = 15) and MLE (n = 15) at doses of 10-15 g/kg/day in parenteral nutrition (PN). On day 14 we collected serum and tissues. Using gas-liquid chromatography, percentage fatty acids were measured in serum, brain, and liver phospholipid. Comparisons were made to reference values from litter-matched controls (n = 8).

RESULTS

Comparing median values, linoleic acid (LA) was lower for MLE vs SLE in serum (-27%), liver (-45%), and brain (-33%) (P < 0.001). AA was lower for MLE in serum (-25%), liver (-40%), and brain (-10%). DHA was higher for MLE in serum (+50%), liver (+200%), and brain (+10%). AA levels were lower for MLE vs control piglets in serum (-81%), liver (-63%), and brain (-9%). DHA levels were higher in serum (+41%), liver (+38%), and brain (+19%).

CONCLUSION

This study in piglets has shown that, at unrestricted doses, MLE treatment is associated with low serum and tissue AA compared with SLE and healthy litter-matched controls. Although not yet proven, low tissue AA levels may have functional consequences, and these data support current practice avoiding MLE dose restriction.

Parenteral Nutrition in the Neonatal Intensive Care Unit: Intravenous Lipid Emulsions

Intravenous lipid emulsions (ILEs) are a source of nonprotein calories and fatty acids and help promote growth in preterm infants and infants with intestinal failure. An ILE dose and oil source determines its fatty acid, phytosterol, and vitamin E delivery. These factors play a role in the infant's risk for essential fatty acid deficiency and cholestasis, and help modulate inflammation, immunity, and organ development. This article reviews different ILEs and their constituents and their relationship with neonatal health.

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.

Lipid strategies to prevent intestinal failure-associated liver disease in neonates: A pilot trial

BACKGROUND

Intestinal failure-associated liver disease (IFALD) occurs in up to 50% of neonates treated with prolonged parenteral nutrition. Preventative strategies for IFALD include soybean oil lipid emulsion (SOLE) minimization and use of mixed-oil intravenous lipid emulsions (ILE). We conducted a pilot study prospectively comparing these two ILE strategies in the prevention of IFALD in neonates who required abdominal surgery.

METHODS

We randomized eligible neonates to SOLE at 1 g/kg/day (SOLE Min) or mixed-oil ILE containing fish oil (MOLE) at 3 g/kg/day. These treatment groups were also compared with historic controls who received SOLE at 2-3 g/kg/day (SOLE Historic). We defined IFALD as a direct bilirubin >2 mg/dl on two measurements. Secondary outcomes included laboratory, growth, clinical, and nutrition outcomes.

RESULTS

A total of 24 prospective and 24 historic patients were included. There was no difference in the rate of IFALD. However, there was a difference in the weekly change of direct bilirubin levels (SOLE Historic +0.293 mg/dl/week vs MOLE, P < 0.001; SOLE Min +0.242 mg/dl/week vs MOLE, P < 0.001). The MOLE group also had a lower direct bilirubin at study completion (SOLE Historic, 1.7 ± 1.7 mg/dl; SOLE Min, 1.6 ± 1.4 mg/dl; MOLE, 0.4 ± 0.4 mg/dl; P = 0.002) and received greater total calories (P = 0.008).

CONCLUSION

The rate of IFALD did not differ when comparing ILE strategies in neonates requiring abdominal surgery. However, the MOLE group maintained significantly lower direct bilirubin levels over time while receiving increased calories. This pilot study highlights the need for further randomized controlled trials comparing these ILE strategies.

Intestinal Continuity Alleviates Pediatric Intestinal Failure-Associated Liver Disease

Background

Type I short bowel syndrome (SBS) occurs after a critical reduction in the functional gut mass and resection of intestinal continuity after ileostomy or jejunostomy for necrotizing enterocolitis (NEC), intestinal atresia or other causes. SBS is often accompanied with intestinal failure-associated liver disease (IFALD) who requires long-term parenteral nutrition (PN). Our study aimed to observe the effect of intestinal continuity on the hepatic function of pediatric intestinal failure (IF) patients with type I SBS.

Methods

The pre-and post-anastomosis medical records of 35 pediatric patients with type I SBS from April 2013 to April 2019 were reviewed retrospectively. The average growth (cm/month) in the proximal and distal small bowel lengths was calculated as the growth in intestinal length (cm)/the duration (month) from enterostomy to anastomosis. The changes in hepatic function from enterostomy to anastomosis were evaluated by assessment of hepatic function before anastomosis for 6 weeks and after anastomosis for 4 weeks.

Results

The average growth in proximal intestinal length was 9.3 cm/month (±7.2) in neonates and 2.8 cm/month (1.3, 11.9) in infants and children, and in distal intestinal length was 1.5 cm/month (0, 2.7) in neonates and 0.4 cm/month (0, 1.4) in infants and children. The incidence of IFALD was 28.6% 1 month before anastomosis and 20.0% 1 month after anastomosis (p < 0.05).

Conclusion

In pediatric type I SBS with IFALD, restoration of intestinal continuity may alleviate liver injury. There was an intestinal compensatory effect on the growth in the intestinal length after resection, and better results were seen in neonates in terms of intestinal length growth.

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.

[ESPEN Practical Guideline: Clinical nutrition in liver disease]

BACKGROUND

the Practical Guideline is based on the current scientific ESPEN guide on Clinical Nutrition in Liver Disease.

METHODS

it has been shortened and transformed into flow charts for easier use in clinical practice. The guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with chronic liver disease.

RESULTS

a total of 103 statements and recommendations are presented with short commentaries for the nutritional and metabolic management of patients with (i) acute liver failure, (ii) alcoholic steatohepatitis, (iii) non-alcoholic fatty liver disease, (iv) liver cirrhosis, and (v) liver surgery/transplantation. Disease-related recommendations are preceded by general recommendations on the diagnosis of nutritional status in liver patients and on liver complications associated with medical nutrition.

CONCLUSION

this Practical Guideline gives guidance to health care providers involved in the management of liver disease on how to offer optimal nutritional care.

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

ASPEN definitions in pediatric intestinal failure

Pediatric intestinal failure (PIF) is a relatively rare disease entity which requires focused interdisciplinary care and specialized nutrition management. There has long been a lack of consensus in the definition of key terms related to PIF due to its rarity and plethora of small studies rather than large trials. As such, the American Society for Parenteral and Enteral Nutrition (ASPEN) Pediatric Intestinal Failure Section, composed of clinicians from a variety of disciplines caring for children with intestinal failure, is uniquely poised to provide insight into this definition void. This document is the product of an effort by the Section to create evidence-based consensus definitions, with the goal of allowing for appropriate comparisons between clinical studies and measurement of longterm patient outcomes. This manuscript was approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

An overview of the current management of short-bowel syndrome in pediatric patients

Short-bowel syndrome (SBS) is defined as a state of malabsorption after resection or loss of a major portion of the bowel due to congenital or acquired factors. This article presents an overview on the recent management of pediatric SBS. The pediatric SBS population is very heterogeneous. The incidence of SBS is estimated to be 24.5 per 100,000 live births. The nutritional, medical, and surgical therapies available require a comprehensive evaluation. Thus, multidisciplinary intestinal rehabilitation programs (IRPs) are necessary for the management of these complex patients. The key points of focus in IRP management are hepato-protective strategies to minimize intestinal failure-associated liver disease; the aggressive prevention of catheter-related bloodstream infections; strategic nutritional supply to optimize the absorption of enteral calories; and the management and prevention of small bowel bacterial overgrowth, nephrocalcinosis, and metabolic bone disease. As the survival rate of children with SBS currently exceeds 90%, the application of small bowel transplantation has been evolving. The introduction of innovative treatments, such as combined therapy of intestinotrophic hormones, including glucagon-like peptide-2, may lead to further improvements in patients' quality of life.

ESPEN practical guideline: Clinical nutrition in liver disease

BACKGROUND

The Practical guideline is based on the current scientific ESPEN guideline on Clinical Nutrition in Liver Disease.

METHODS

It has been shortened and transformed into flow charts for easier use in clinical practice. The guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with chronic liver disease.

RESULTS

A total of 103 statements and recommendations are presented with short commentaries for the nutritional and metabolic management of patients with (i) acute liver failure, (ii) alcoholic steatohepatitis, (iii) non-alcoholic fatty liver disease, (iv) liver cirrhosis, and (v) liver surgery/transplantation. The disease-related recommendations are preceded by general recommendations on the diagnostics of nutritional status in liver patients and on liver complications associated with medical nutrition.

CONCLUSION

This practical guideline gives guidance to health care providers involved in the management of liver disease to offer optimal nutritional care.

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.

Composite Lipid Emulsion for the Infant at Risk of Intestinal Failure-associated Liver Disease: The Canadian Perspective

Currently, in North America we are fortunate to have a number of available options for lipid emulsions to be used in the parenteral nutrition regimens for infants and children, including for long-term parenteral nutrition given intestinal failure. Neonates and infants in particular are at risk for intestinal failure-associated liver disease (IFALD). The choice of parenteral lipid emulsion will influence the risk and severity of IFALD. The purpose of this review is to discuss the rationale for the composite lipid emulsion SMOFlipid that includes soybean, medium-chain triglycerides, olive and fish oils for IFALD, with focus on the Canadian practice and experience.

Review of parenteral nutrition-associated liver disease

Parenteral nutrition has been widely used in patients whose gastrointestinal tract is anatomically or physiologically unavailable for sufficient food intake. It has been considered lifesaving but is not without adverse effects. It has been proven to cause liver injury through different mechanisms. We present a review of parenteral nutrition-associated liver disease.

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.

TGR5 signaling mitigates parenteral nutrition-associated liver disease

Bile acid receptors regulate the metabolic and immune functions of circulating enterohepatic bile acids. This process is disrupted by administration of parenteral nutrition (PN), which may induce progressive hepatic injury for unclear reasons, especially in the newborn, leading to PN-associated liver disease. To explore the role of bile acid signaling on neonatal hepatic function, we initially observed that Takeda G protein receptor 5 (TGR5)-specific bile acids were negatively correlated with worsening clinical disease markers in the plasma of human newborns with prolonged PN exposure. To test our resulting hypothesis that TGR5 regulates critical liver functions to PN exposure, we used TGR5 receptor deficient mice (TGR5^-/-). We observed PN significantly increased liver weight, cholestasis, and serum hepatic stress enzymes in TGR5^-/- mice compared with controls. Mechanistically, PN reduced bile acid synthesis genes in TGR5^-/-. Serum bile acid composition revealed that PN increased unconjugated primary bile acids and secondary bile acids in TGR5^-/- mice, while increasing conjugated primary bile acid levels in TGR5-competent mice. Simultaneously, PN elevated hepatic IL-6 expression and infiltrating macrophages in TGR5^-/- mice. However, the gut microbiota of TGR5^-/- mice compared with WT mice following PN administration displayed highly elevated levels of Bacteroides and Parabacteroides, and possibly responsible for the elevated levels of secondary bile acids in TGR5^-/- animals. Intestinal bile acid transporters expression was unchanged. Collectively, this suggests TGR5 signaling specifically regulates fundamental aspects of liver bile acid homeostasis during exposure to PN. Loss of TGR5 is associated with biochemical evidence of cholestasis in both humans and mice on PN.NEW & NOTEWORTHY Parenteral nutrition is associated with deleterious metabolic outcomes in patients with prolonged exposure. Here, we demonstrate that accelerated cholestasis and parental nutrition-associated liver disease (PNALD) may be associated with deficiency of Takeda G protein receptor 5 (TGR5) signaling. The microbiome is responsible for production of secondary bile acids that signal through TGR5. Therefore, collectively, these data support the hypothesis that a lack of established microbiome in early life or under prolonged parenteral nutrition may underpin disease development and PNALD.

Predictors of Intestinal Adaptation in Children

In children, short-bowel syndrome (SBS) accounts for two-thirds of the cases of intestinal failure, and motility disorders and congenital mucosal diarrheal disorders account for the remaining one-third. Children with SBS are supported primarily by parenteral nutrition, which is the single-most important therapy contributing to their improved prognosis. More than 90% of children with SBS who are cared for at experienced intestinal rehabilitation programs survive, and roughly 60% to 70% undergo intestinal adaptation and achieve full enteral autonomy. This article focuses on the predictors of pediatric intestinal adaptation and discusses the pathophysiology and clinical management of children with SBS.

Home parenteral nutrition in patients receiving palliative care: a curriculum-based review

Difficulty with maintaining nutritional intake is common in patients with cancer. European guidance suggests that wherever possible nutritional support should first be provided by the oral or enteral route. Where this is not possible, for example, in malignant small bowel obstruction, parenteral nutrition (PN) may be considered. In palliative care, it is generally accepted that the significant risks and burdens of PN outweigh the potential benefits in patients with an expected survival <2 months. Determining prognosis is crucial when helping patients to make decisions regarding appropriate care pathways; however, this remains challenging. An overview of clinical issues and prognostic indicators related to selecting patients appropriately for palliative PN is given to cover the relevant advanced competencies of the 2010 Gastroenterology Curriculum. The organisation of Home Parenteral Nutrition (HPN) services in England is described including the associated risks and burdens of HPN in the palliative patient.

Phytosterolemia and γ-glutamyl transferase in adults with parenteral nutrition: Fish versus vegetal lipids: A randomized clinical trial

OBJECTIVES

Fish oil (FO)-based lipid emulsions (LEs) have been reported to prevent hepatic dysfunction in patients treated with parenteral nutrition (PN). We studied patients with alterations of γ-glutamyl transferase (GGT) associated with the administration of PN containing olive/soybean (O/S)-based LE. The aim of this study was to determine whether the strategy of reducing the lipid dose by 50%, by changing to an FO-based LE, reduced plasma levels of phytosterols (PS) and GGT more effectively and safely, than the strategy of reducing lipid contribution by 50% while maintaining the same LE composition.

METHODS

A randomized double-blind clinical trial was carried out in patients with normal initial GGT, who after a minimum of 1 wk of daily PN (0.8 g/kg of O/S-based LE) presented with GGT values twice the upper normal value. At the time of randomization 1:1, lipids were reduced to 0.4 g/kg daily. Group A maintained O/S LE and group B changed to FO LE. The primary endpoints were reduction of plasmatic PS and GGT on day 7 after randomization, performed in the study population per protocol by Student's t test and simple linear regression. Secondary outcomes included alkaline phosphatase (AP), alanine transaminase (ALT), and total bilirubin (BIL), and safety variables.

RESULTS

Nineteen patients were included. On day 7 after randomization, GGT and AP values were higher in the O/S group (n = 10; GGT: median [Med], 4.99; interquartile range [IQR], 4.09; AP: Med, 2.59 μkat/L; IQR 1.74) than in the FO group (n = 9; GGT: Med, 2.26 μkat/L; IQR, 1.07; AP: Med, 1.2 μkat/L; IQR 1.44). Although there were no differences in ALT and BIL values, the ALT decrease was larger and more statistically significant in the FO group than in the O/S group (P = 0.009). Total PS (Med, 21.10 μg/mL; IQR, 5.50) in the O/S group was higher than in the FO group (Med, 13.4 μg/mL; IQR, 10.65; P = 0.002). Significant decreases in PS and their fractions were observed, with the exception of campesterol and stigmasterol.

CONCLUSION

Plasma accumulation of PS and high values of GGT, AP, and ALT can be prevented with the exclusive administration of FO-based LE.

Mixed Lipid, Fish Oil, and Soybean Oil Parenteral Lipids Impact Cholestasis, Hepatic Phytosterol, and Lipid Composition

OBJECTIVES

In parenteral nutrition-dependent infants and children, intestinal failure (IF)-associated liver disease (IFALD) remains an important problem. A comparative study was undertaken of parenteral mixed lipid (ML), ω-3 predominant fish oil (FO), and ω-6 predominant soybean oil (SO) emulsions in regards to hepatic phytosterol, neutral lipid, fatty acid (FA) content, and the relationship to cholestasis in piglets.

METHODS

Neonatal piglets received parenteral nutrition, varying in lipid dose (5 or 10 g· kg · day) and formulation: SO5 (n = 5), SO10 (n = 5), FO5 (n = 5), and ML10 (n = 5). On day 14, liver chemistry, bile flow, histology and neutral lipid staining were assessed. Hepatic triglyceride FA content was determined using thin layer and gas chromatography, and phytosterol content was assessed using gas chromatography-mass spectrometry.

RESULTS

SO groups had higher prevalence of biochemical cholestasis (P < 0.04) and lower bile flow (P < 0.0001). Hepatic campesterol, stigmasterol, and β-sitosterol were highest in SO10 (P < 0.0001). Hepatic FA (P < 0.03) and ω-6/ω-3 FA ratio (P < 0.0001) were higher in the SO groups. Neutral lipid accumulation (P = 0.3) and liver histology (P = 0.16) were not different between groups. Univariate predictors of bile flow were: campesterol (r = -0.77, P = 0.001), β-sitosterol (r = -0.74, P = 0.002), stigmasterol (r = -0.74, P = 0.002), ω-6 FA (r = -0.72, P = 0.002), and ω-3 FA (r = 0.59, P = 0.02). Only campesterol independently predicted bile flow.

CONCLUSIONS

ML and FO lipid emulsions reduce cholestasis in association with lowered hepatic phytosterol and lipid content. Lower hepatic phytosterol and ω-6 FA content, and higher ω-3 FA content are hepatoprotective. Multivariate analysis suggests reduced phytosterol accumulation may best explain the hepatoprotective effect of fish oil-containing lipids.

The Role of Parenteral Lipids in the Development of Hepatic Dysfunction and Hepatic Steatosis in a Mouse Model of Total Parenteral Nutrition

Parenteral nutrition-associated liver disease, a common and life-threating complication among people who require long-term parenteral nutrition, has been associated with abnormal liver function, cholestasis, steatosis and fibrosis. Intravenous soybean lipids may be associated with the development of liver disease. We therefore examined whether different doses of parenteral lipids would affect the development of liver disease, and further investigated the possible pathogenesis of it. C57BL/6J mice with a central catheter placed in the right jugular vein were divided into three groups. The control group received normal mouse chow with intravenous normal saline; The lipids group received parenteral nutrition solution (0.14 g lipids per day); the H-lipids group received parenteral nutrition solution with twice the amount of lipids (0.3 g lipids per day). Changes in body weight, serum biochemical parameters, liver histology and farnesoid X receptor gene expression in the liver were assessed. The values of serum direct bilirubin, total bilirubin and cholesterol were markedly increased in the H-lipids group at day 7. The predominant histologic finding in the H-lipids group was steatosis, and the steatosis score in the H-lipids group was much higher than in the other two groups at either day 5 or day 7. Hepatic expression of farnesoid X receptor mRNA decreased after 7 d of parenteral nutrition. High doses of parenteral lipids are more likely to develop liver disease in a mouse model of parenteral nutrition. Farnesoid X receptor may play a key role in the development of parenteral nutrition-associated liver disease.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Impact of Clinical Use of Parenteral Lipid Emulsions on Bile Acid Metabolism and Composition in Neonatal Piglets

BACKGROUND

Neonates with intestinal failure dependent on parenteral nutrition (PN) are at risk of intestinal failure-associated liver disease (IFALD). PN lipid composition relates to the risk of IFALD, but the mechanisms are poorly understood. We investigated the effects of soybean oil (SO), a mixed-lipid (ML) emulsion containing fish oil (FO), and a pure FO. We hypothesized FO-containing PN lipids would result in increased gene expression of canalicular bile acid transporters and a larger, more hydrophilic bile acid pool, predictive of increased bile flow.

METHODS

Neonatal piglets were allocated to receive 1 of SO, ML, or FO throughout 14 days of PN feeding. Relative expression of genes involved in bile acid synthesis and transport were determined through quantitative polymerase chain reaction. Bile secreted from the liver was collected and measured. Bile acid composition was determined using tandem mass spectrometry. Regression analysis was used to determine predictors of bile flow.

RESULTS

PN reduced bile acid secretion (P < .001). FO-containing PN lipids were associated with greater expression of bile acid and organic solute transport genes (P < .05) and greater secretion of hydrophobic bile acids (P < .001). Farnesoid X receptor (P = .01), bile salt export pump (P < .01), multidrug resistant protein 2 (P < .01), and unconjugated hyocholic acid (P < .001) independently predicted bile flow.

CONCLUSIONS

PN lipid modulation altered bile acid metabolism and composition. These alterations may explain the hepatoprotective effects of FO-containing PN lipids and support their use in the prevention and treatment of IFALD.

Etiology and prognosis of pediatric short bowel syndrome

Pediatric intestinal failure is a complex and devastating condition defined as the inability of the intestine to absorb an adequate amount of fluid and nutrients to sustain life. The primary goal of intestinal failure treatment is to achieve enteral autonomy with a customized treatment plan. Although recent improvements in intestinal failure patient care have led to significant improvements in the morbidity and mortality rate, children with intestinal failure are at risk for multiple complications such as intestinal failure associated liver disease, recurrent septic episodes, central line complications, metabolic bone disease, impaired kidney function, and failure to thrive. In this article, we review the current literature on the etiology and factors affecting prognosis of pediatric IF.

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.

Surgical Anatomy Does Not Affect the Progression of Intestinal Failure-Associated Liver Disease in Neonatal Piglets

BACKGROUND

Intestinal failure-associated liver disease (IFALD) causes significant morbidity in neonates with short bowel syndrome (SBS) dependent on parenteral nutrition (PN). Resected ileum, with loss of the ileocecal valve (ICV), is the most common anatomy in SBS, yet its impact on IFALD has not been adequately studied.

METHODS

Neonatal piglets were randomized to 75% intestinal resection with jejunocolic anastomosis (JC, n = 12), 75% resection with jejunoileal anastomosis and intact ICV (JI, n = 13), PN-fed sham (sham, n = 14), or sow-fed control (SF, n = 8). Surgical and sham piglets received 100% PN for 14 days before bile flow was measured and blood chemistry, liver pathology, jejunal permeability, and bacterial translocation were assessed.

RESULTS

Bile flow was lower for PN-fed compared with SF (P = .002) but not different between the PN-fed groups. Total bilirubin (P = .03) and liver pathology (P < .001) were greater in PN-fed than SF groups but not different between PN-fed groups. Serum bile acids were increased in sham (P = .01) but not different between SBS groups. PN-fed piglets with sepsis had lower bile flow (P = .001) and increased bilirubin (P = .04). Neither jejunal permeability nor bacterial translocation were different between JC, JI, or sham groups.

CONCLUSION

Contrary to our hypothesis, the remnant anatomy does not appear to worsen the progression of IFALD. However, the role of sepsis in IFALD should be further explored, in addition to other mechanisms, including PN factors, host immune responses, and intestinal bacterial dysbiosis.

Liver Disease in Patients on Total Parenteral Nutrition

Parenteral nutrition-associated liver disease (PNALD) spectrum ranges from liver enzyme abnormalities to steatosis to fibrosis, and, eventually, cirrhosis from total parenteral nutrition (TPN). The pathophysiology is postulated to be multifactorial. Diagnosis in adults is primarily by exclusion, eliminating other causes of chronic liver disease or cirrhosis, and other factors seen in critically ill or postoperative patients on TPN. Principal treatment is avoiding TPN. If this is not feasible, research supports fish oil-based lipid emulsions in TPN formulations to reduce risk and progression of PNALD. With liver and intestinal failure, liver and intestine transplant is an option.

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.

Endoplasmic Reticulum Stress Is Implicated in Intestinal Failure-Associated Liver Disease

BACKGROUND

Intestinal failure-associated liver disease (IFALD) is the most serious consequence of long-term parenteral nutrition for intestinal failure. Little is known about the pathogenesis of IFALD, although many of the risk factors are also linked to endoplasmic reticulum stress (ERS). We propose that ERS may have a role in the development of IFALD.

METHODS

Archived liver tissue from patients with early and late IFALD, as well as from normal controls, was used for RNA extraction and immunohistochemistry to demonstrate the presence of ERS markers.

RESULTS

Mean relative RNA levels of glucose regulatory protein 78 in normal liver (n = 3), early IFALD (n = 15), and late IFALD (n = 5) were 0.5, 37.86, and 212.11, respectively. Mean relative expression of ERDj4 (ER DnaJ homologue 4, a downstream ERS effector) in normal liver, early IFALD, and late IFALD was 5.51, 216.68, and 213.22, respectively. The degree of splicing of X-box binding protein 1 in IFALD compared with normal liver was significantly higher (mean, 0.0779 normal, 0.102 early IFALD, 0.2063 late IFALD).

CONCLUSIONS

This is the first description of ERS in IFALD. This information may open up new therapeutic possibilities in the form of chemical chaperones known to ameliorate ERS.

Animal models of gastrointestinal and liver diseases. Animal models of infant short bowel syndrome: translational relevance and challenges

Intestinal failure (IF), due to short bowel syndrome (SBS), results from surgical resection of a major portion of the intestine, leading to reduced nutrient absorption and need for parenteral nutrition (PN). The incidence is highest in infants and relates to preterm birth, necrotizing enterocolitis, atresia, gastroschisis, volvulus, and aganglionosis. Patient outcomes have improved, but there is a need to develop new therapies for SBS and to understand intestinal adaptation after different diseases, resection types, and nutritional and pharmacological interventions. Animal studies are needed to carefully evaluate the cellular mechanisms, safety, and translational relevance of new procedures. Distal intestinal resection, without a functioning colon, results in the most severe complications and adaptation may depend on the age at resection (preterm, term, young, adult). Clinically relevant therapies have recently been suggested from studies in preterm and term PN-dependent SBS piglets, with or without a functional colon. Studies in rats and mice have specifically addressed the fundamental physiological processes underlying adaptation at the cellular level, such as regulation of mucosal proliferation, apoptosis, transport, and digestive enzyme expression, and easily allow exogenous or genetic manipulation of growth factors and their receptors (e.g., glucagon-like peptide 2, growth hormone, insulin-like growth factor 1, epidermal growth factor, keratinocyte growth factor). The greater size of rats, and especially young pigs, is an advantage for testing surgical procedures and nutritional interventions (e.g., PN, milk diets, long-/short-chain lipids, pre- and probiotics). Conversely, newborn pigs (preterm or term) and weanling rats provide better insights into the developmental aspects of treatment for SBS in infants owing to their immature intestines. The review shows that a balance among practical, economical, experimental, and ethical constraints will determine the choice of SBS model for each clinical or basic research question.

Glucagon-Like Peptide 2 Improves Cholestasis in Parenteral Nutrition--Associated Liver Disease

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) remains a significant cause of morbidity and mortality in neonates with intestinal failure. Although glucagon-like peptide-2 (GLP-2) is being advanced as therapy, the effect of GLP-2 treatment on PNALD is unknown. We aim to investigate the effect of exogenous GLP-2 administration on hepatic function in a neonatal piglet model of PNALD.

METHODS

Neonatal piglets (aged 2-6 days) underwent jugular venous catheterization to receive isonitrogenous, isocaloric parenteral nutrition (PN). Piglets were allocated to 2 groups: group 1 (n = 8) received saline while group 2 (n = 7) received GLP-2 (at 11 nmol/kg/d). After 17 days, piglets underwent terminal laparotomy, and bile flow was measured. Liver specimens were analyzed histologically and with immunoperoxidase staining. Age-matched sow-reared control piglets (group 3, n = 8) were used for comparison.

RESULTS

Both groups 1 and 2 receiving PN developed cholestasis relative to sow-reared controls, as evidenced by a decrease in bile flow and increase in serum total bilirubin. However, group 2 had improved bile flow (1.35 vs 0.73 µL/g; P = .02) and diminished bilirubin (38.0 vs 78.5 µmol/L; P = .008) compared with group 1. Group 2 also had lower serum alanine aminotransferase levels, a marker of liver injury. Histologically, the liver specimens in group 1 had marked hepatocyte pigmentation, which was decreased in group 2 specimens.

CONCLUSIONS

The exogenous administration of GLP-2 is associated with the improvement of cholestasis and liver injury. This study introduces a novel role for GLP-2 in improving PNALD in the setting of prolonged PN duration.

Randomized controlled trial of early enteral fat supplement and fish oil to promote intestinal adaptation in premature infants with an enterostomy

OBJECTIVE

To test the hypothesis that early enteral supplementing fat and fish oil decreases the duration of parenteral nutrition (PN) and increases enteral nutrition (EN) before bowel reanastomosis in premature infants with an enterostomy.

STUDY DESIGN

Premature infants (<2 months old) who had an enterostomy and tolerated enteral feeding at 20 mL/kg/day were randomized to usual care (control=18) or early supplementing enteral fat supplement and fish oil (treatment=18). Intravenous lipid was decreased as enteral fat intake was increased. Daily weight, clinical and nutrition data, and weekly length and head circumference were recorded. The primary outcomes were the duration of PN and volume of EN intake, and the secondary outcomes were weight gain (g/day), ostomy output (mL/kg/d), and serum conjugated bilirubin level (mg/dL) from initiating feeding to reanastomosis. Data were analyzed by Student t test or Wilcoxon rank sum test.

RESULTS

There were no differences in the duration of PN, ostomy output, and weight gain between the 2 groups before reanastomosis. However, supplemented infants received less intravenous lipid, had greater EN intake, and lower conjugated bilirubin before reanastomosis, and they also received greater total calorie, had fewer sepsis evaluations and less exposure to antibiotics and central venous catheters before reanastomosis, and had greater weight and length gain after reanastomosis (all P<.05).

CONCLUSION

Early enteral feeding of a fat supplement and fish oil was associated with decreased exposure to intravenous lipid, increased EN intake, and reduced conjugated bilirubin before reanastomosis and improved weight and length gain after reanastomosis in premature infants with an enterostomy.

A.S.P.E.N. clinical guidelines: support of pediatric patients with intestinal failure at risk of parenteral nutrition-associated liver disease

BACKGROUND

Children with severe intestinal failure and prolonged dependence on parenteral nutrition are susceptible to the development of parenteral nutrition-associated liver disease (PNALD). The purpose of this clinical guideline is to develop recommendations for the care of children with PN-dependent intestinal failure that have the potential to prevent PNALD or improve its treatment.

METHOD

A systematic review of the best available evidence to answer a series of questions regarding clinical management of children with intestinal failure receiving parenteral or enteral nutrition was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group. A consensus process was used to develop the clinical guideline recommendations prior to external and internal review and approval by the American Society for Parenteral and Enteral Nutrition Board of Directors.

QUESTIONS

(1) Is ethanol lock effective in preventing bloodstream infection and catheter removal in children at risk of PNALD? (2) What fat emulsion strategies can be used in pediatric patients with intestinal failure to reduce the risk of or treat PNALD? (3) Can enteral ursodeoxycholic acid improve the treatment of PNALD in pediatric patients with intestinal failure? (4) Are PNALD outcomes improved when patients are managed by a multidisciplinary intestinal rehabilitation team?