Alteration of canalicular transporters in a mouse model of total parenteral nutrition

One-year Experience With Composite Intravenous Lipid Emulsion in Children on Home Parenteral Nutrition

BACKGROUND

Composite lipid emulsion (CLE) composed of soybean oil, medium-chain triglycerides, olive oil, and fish oil is approved in the US for parenterally fed adults. For stable children discharged on home parenteral nutrition (HPN) without cholestasis (direct bilirubin > 2.0 mg/dL), CLE has theoretical benefits over soybean-based intravenous lipid emulsion due to reduced phytosterol exposure with higher calorie support to permit reduced glucose infusion rates (GIRs), omega-3 supplementation, and supplemental α-tocopherol.

METHODS

In this prospective, single-center open-label research study, safety and efficacy outcomes were evaluated in patients on HPN younger than 18 years treated with CLE at 1 to 3 g · kg-1 · day-1 over 12 months. The primary outcome was change in anthropometrics and GIRs compared with baseline. Secondary outcomes were changes in fatty acid profiles and liver function and enzyme tests compared with baseline.

RESULTS

Fifty-seven subjects were treated with a median age of 7 years. The diagnosis was short bowel syndrome in 72%. Change in practice was associated with a decrease in mean GIRs from 17 to 14 mg · kg-1 · h-1 at 4 to 6 months postbaseline and beyond with a coincidental decline in mean arachidonic acid and stable growth parameters. No significant adverse events were noted.

CONCLUSIONS

CLE was safe and well-tolerated in stable children on HPN at 1 year, but further studies are needed in this population to appreciate long-term outcomes.

Growth in Infants and Children With Intestinal Failure-associated Liver Disease Treated With Intravenous Fish Oil

BACKGROUND

Infants with intestinal failure (IF) and IF-associated liver disease (IFALD) are at risk for poor somatic growth because of increased metabolic demands, inadequate intake, intestinal malabsorption, chronic liver disease and other comorbidities. There are limited data on the nutritional adequacy of intravenous fish oil lipid emulsion (FOLE) compared with standard soybean oil lipid emulsion (SOLE) in the setting of intestinal failure.

AIMS

To describe growth patterns in a large cohort of infants with IFALD treated with FOLE.

METHODS

We compared growth data from infants enrolled in a single-center, prospective FOLE study to published norms, as well as to a multicenter, historical cohort of infants with IF treated with SOLE.

RESULTS

One hundred thirty-eight infants with IFALD were treated with FOLE and 108 with SOLE. Compared with normative growth curves from WHO and published preterm data, infants in both groups from 6 to 11 months postmenstrual age exhibited declines in mean weight- and length-for-age z scores. At 24 months postmenstrual age compared with WHO growth data, infants treated with FOLE had a mean (95% confidence interval [CI]) weight-for-age z-score of 0.13 (-0.18 to 0.45) and length-for-age z-score of 0.07 (-0.33 to 0.47). In comparison, at 24 months postmenstrual age, infants treated with SOLE had a mean weight for age z-score of -0.93 (-1.20 to -0.67) and mean length for age z-score of -2.33 (-2.75 to -1.91). Independent predictors of higher weight, length and head circumference z-scores included older postmenstrual age at baseline, fewer central line-associated blood stream infections, resolution of cholestasis, type of intravenous fat emulsion (FOLE vs SOLE) and female sex.

CONCLUSIONS

Infants with IFALD treated with FOLE showed comparable somatic growth to those treated with SOLE in early infancy, and improved somatic growth up to 24 months of age, supporting its wider use in this patient population.

Mechanisms of Parenteral Nutrition-Associated Liver and Gut Injury

Parenteral nutrition (PN) has revolutionized the care of patients with intestinal failure by providing nutrition intravenously. Worldwide, PN remains a standard tool of nutrition delivery in neonatal, pediatric, and adult patients. Though the benefits are evident, patients receiving PN can suffer serious cholestasis due to lack of enteral feeding and sometimes have fatal complications from liver injury and gut atrophy, including PN-associated liver disease or intestinal failure-associated liver disease. Recent studies into gut-systemic cross talk via the bile acid-regulated farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) axis, gut microbial control of the TGR5-glucagon-like peptide (GLP) axis, sepsis, and role of prematurity of hepatobiliary receptors are greatly broadening our understanding of PN-associated injury. It has also been shown that the composition of ω-6/ω-3 polyunsaturated fatty acids given parenterally as lipid emulsions can variably drive damage to hepatocytes and cell integrity. This manuscript reviews the mechanisms for the multifactorial pathogenesis of liver disease and gut injury with PN and discusses novel ameliorative strategies.

Trigger mechanisms of secondary sclerosing cholangitis in critically ill patients

INTRODUCTION

In recent years the development of secondary sclerosing cholangitis in critically ill patients (SSC-CIP) has increasingly been perceived as a separate disease entity. About possible trigger mechanisms of SSC-CIP has been speculated, systematic investigations on this issue are still lacking. The purpose of this study was to evaluate the prevalence and influence of promoting factors.

METHODS

Temporality, consistency and biological plausibility are essential prerequisites for causality. In this study, we investigated the temporality and consistency of possible triggers of SSC-CIP in a large case series. Biological plausibility of the individual triggers is discussed in a scientific context. SSC-CIP cases were recruited retrospectively from 2633 patients who underwent or were scheduled for liver transplantation at the University Hospital Charité, Berlin. All patients who developed secondary sclerosing cholangitis in association with intensive care treatment were included. Possible trigger factors during the course of the initial intensive care treatment were recorded.

RESULTS

Sixteen patients (68% males, mean age 45.87 ± 14.64 years) with a confirmed diagnosis of SSC-CIP were identified. Of the 19 risk factors investigated, particularly severe hypotension with a prolonged decrease in mean arterial blood pressure (MAP) to <65 mmHg and systemic inflammatory response syndrome (SIRS) were established as possible triggers of SSC-CIP. The occurrence of severe hypotension appears to be the first and most significant step in the pathogenesis. It seems that severe hypotension has a critical effect on the blood supply of bile ducts when it occurs together with additional microcirculatory disturbances.

CONCLUSIONS

In critically ill patients with newly acquired cholestasis the differential diagnosis of SSC-CIP should be considered when they have had an episode of haemodynamic instability with a prolonged decrease in MAP, initial need for large amounts of blood transfusions or colloids, and early development of a SIRS.

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

BACKGROUND

Increased serum concentrations of plant sterols, including stigmasterol, during parenteral nutrition (PN) have been linked with serum biochemical signs of intestinal failure-associated liver disease (IFALD), whereas clinical data on their correlation to histologic liver injury have been limited.

OBJECTIVE

We studied interrelations between serum noncholesterol sterols and histologic liver injury in pediatric-onset intestinal failure (IF).

DESIGN

Serum plant sterols (stigmasterol, avenasterol, sitosterol, and campesterol), cholestanol, and cholesterol precursors (cholestenol, lathosterol, and desmosterol) were measured in 50 IF patients at a median age 7.3 y and in 86 matched controls. Forty patients underwent liver biopsies. Sixteen patients had been receiving PN for 45 mo, and 34 patients had received PN for 9.1 mo but had not received PN for 5.4 y.

RESULTS

Serum plant sterols were higher in patients who were currently receiving PN than in controls and were related to conjugated bilirubin (r = 0.799-0.541, P < 0.05). During PN, the ratio of serum stigmasterol to cholesterol was 3.3-fold higher in patients with portal inflammation, and the ratio of avenasterol to cholesterol was 3.9-fold higher in patients with cholestasis (P < 0.05 for both). Ratios of stigmasterol and avenasterol to cholesterol were correlated with portal inflammation (r = 0.549-0.510, P < 0.05), cholestasis (r = 0.501-0.491, P = 0.048-0.053), and serum bile acids (r = 0.591-0.608, P < 0.05). The median (IQR) ratio of serum cholestanol to cholesterol was higher during (269 100× μg/mg cholesterol; 203-402 100× μg/mg cholesterol) than after (175 100× μg/mg cholesterol; 156-206 100× μg/mg cholesterol; P < 0.001) weaning off PN and was correlated with cholestasis (r = 0.428), portal inflammation (r = 0.511), and fibrosis (r = 0.323, P < 0.05 for all). After weaning off PN, ratios of cholestenol and lathosterol to cholesterol were >2-fold higher in patients with persistent liver steatosis than in those without steatosis or controls (P < 0.01 for all), whereas lathosterol was correlated with the steatosis grade (r = 0.320, P < 0.050).

CONCLUSIONS

Increased serum stigmasterol and avenasterol concentrations parallel the portal inflammation and cholestasis during PN, thereby reinforcing their contribution to IFALD. A bile acid malabsorption-driven increase in cholesterol synthesis underpins persistent liver steatosis after weaning off PN. Serum cholestanol reflects liver injury in IF patients.

In vivo degradation of cholesterol to bile acids is reduced in patients receiving parenteral nutrition

BACKGROUND

Artificial nutrition is frequently associated with hepatobiliary complications, probably due to the inherent derangement of the gastrointestinal tract physiology. Alterations of hepatic lipid metabolism are likely to be involved. The aim of the present study was to investigate the effect of artificial nutrition on bile acid production, a key event in cholesterol homeostasis, in humans.

PATIENTS AND METHODS

Eleven patients receiving artificial nutrition, either parenteral nutrition (PN; n = 6) or enteral nutrition (EN; n = 5) with no previous history of liver disease, underwent analysis of cholesterol 7α-hydroxylation rates in vivo, a measure of bile acid formation, by isotope release analysis after intravenous injection of [7α-(3)H]cholesterol. The results were compared with those obtained in a population of 16 age-matched control subjects.

RESULTS

Hydroxylation rates were lower in patients with artificial nutrition (PN: 94 ± 13 mg/d; EN: 230 ± 39 mg/d, mean ± SEM) when compared with controls (385 ± 47 mg/d) (P < .01, 1-way analysis of variance). In a patient receiving EN, hydroxylation rates increased 3.5-fold after treatment with the cholecystokinin analogue ceruletide (20 µg bid for 2 weeks intramuscularly). Serum lathosterol-to-cholesterol ratio, a marker of cholesterol synthesis, was also significantly reduced in artificial nutrition, whereas serum levels of fibroblast growth factor 19 (FGF19) were increased.

CONCLUSION

In vivo 7α-hydroxylation is suppressed in artificial nutrition, particularly in PN. The finding associates with reduced cholesterol production, possibly as a metabolic consequence. The data suggest a regulatory role of gastrointestinal hormones and FGF19 on bile acid production and might suggest a pathophysiological basis for some common complications of artificial nutrition, such as gallstone disease and cholestasis.

Prevention and treatment of intestinal failure-associated liver disease in children

Intestinal failure-associated liver disease (IFALD), a serious complication occurring in infants, children, and adults exposed to long-term parenteral nutrition (PN), causes a wide-spectrum of disease, ranging from cholestasis and steatosis to fibrosis and eventually cirrhosis. Known host risk factors for IFALD include low birth weight, prematurity, short bowel syndrome, and recurrent sepsis. The literature suggests that components of PN may also play a part of the multifactorial pathophysiology. Because some intravenous lipid emulsions (ILEs) may contribute to inflammation and interfere with bile excretion, treatment with ILE minimization and/or ILEs composed primarily of omega-3 fatty acids can be helpful, but requires careful monitoring for growth failure and essential fatty acid deficiency (EFAD). Data from randomized controlled trials are awaited to support widespread use of these approaches. Other IFALD treatments include cycling PN, ursodeoxycholic acid, sepsis prevention, photoprotection, and polyvinylchloride-free tubing. Management and prevention of IFALD remains a clinical challenge.

Prevention of parenteral nutrition-associated liver disease: lipid minimization

PURPOSE OF REVIEW

The cause of parenteral nutrition-associated liver disease (PNALD) is unknown. Evidence over the past decade has suggested soybean oil-based intravenous emulsions are a contributing factor to the development of PNALD.

RECENT FINDINGS

This review details the historical and scientific rationale, which associates intravenous lipid emulsion administration and PNALD. The article then reviews our own group's experience with lipid restriction and the reversal of PNALD in neonates on long-term parenteral nutrition. Finally, a clinical approach to restricting soybean-based intravenous lipid emulsions in parenteral nutrition is given.

SUMMARY

An association between intravenous lipid emulsion administration and the development of PNALD seems probable. Strategies to reduce lipid emulsions or develop new, nonsoybean-based lipid emulsions should be considered.