Tauroursodeoxycholic acid (TUDCA) in the prevention of total parenteral nutrition-associated liver disease

Endoplasmic Reticulum Stress in Bronchopulmonary Dysplasia: Contributor or Consequence?

Bronchopulmonary dysplasia (BPD) is the most common complication of prematurity. Oxidative stress (OS) and inflammation are the major contributors to BPD. Despite aggressive treatments, BPD prevalence remains unchanged, which underscores the urgent need to explore more potential therapies. The endoplasmic reticulum (ER) plays crucial roles in surfactant and protein synthesis, assisting mitochondrial function, and maintaining metabolic homeostasis. Under OS, disturbed metabolism and protein folding transform the ER structure to refold proteins and help degrade non-essential proteins to resume cell homeostasis. When OS becomes excessive, the endogenous chaperone will leave the three ER stress sensors to allow subsequent changes, including cell death and senescence, impairing the growth potential of organs. The contributing role of ER stress in BPD is confirmed by reproducing the BPD phenotype in rat pups by ER stress inducers. Although chemical chaperones attenuate BPD, ER stress is still associated with cellular senescence. N-acetyl-lysyltyrosylcysteine amide (KYC) is a myeloperoxidase inhibitor that attenuates ER stress and senescence as a systems pharmacology agent. In this review, we describe the role of ER stress in BPD and discuss the therapeutic potentials of chemical chaperones and KYC, highlighting their promising role in future therapeutic interventions.

Ursodeoxycholic acid for preventing parenteral nutrition-associated cholestasis in neonates: A systematic review and meta-analysis

BACKGROUND

While ursodeoxycholic acid is used in treating parenteral nutrition-associated cholestasis (PNAC) in neonates, its role in prevention is unclear.

OBJECTIVES

In this systematic review and meta-analysis, we attempted to determine the role of ursodeoxycholic acid in preventing PNAC in neonates.

METHODS

PubMed, Embase, Cochrane Library, Scopus, and CINAHL databases were searched on September 16, 2023, for interventional studies comparing ursodeoxycholic acid with placebo.

RESULTS

Of the 6180 unique records identified, five studies were eligible for inclusion (three randomised and two nonrandomised). Evidence from randomised trials showed that ursodeoxycholic acid prophylaxis did not reduce cholestasis, mortality, sepsis, and necrotising enterocolitis. Ursodeoxycholic acid prophylaxis reduced feed intolerance (RR 0.23 (0.09, 0.64); 1 RCT, 102 neonates), peak conjugated bilirubin levels (MD -0.13 (-0.22, -0.04) mg/dL; 1 RCT, 102 neonates), and time to full enteral feeds (MD -2.7 (-5.09, -0.31) days; 2 RCTs, 76 neonates). There was no decrease in hospital stay and parenteral nutrition duration. Data from nonrandomised studies did not show benefit in any of the outcomes. The certainty of the evidence was low to very low.

CONCLUSION

Because of the very low-quality evidence and lack of evidence on critical outcomes, definitive conclusions could not be made on using ursodeoxycholic acid to prevent parenteral nutrition-associated cholestasis in neonates.

Molecular mechanisms of hepatoprotective effect of tectorigenin against ANIT-induced cholestatic liver injury: Role of FXR and Nrf2 pathways

Cholestatic liver injury is caused by toxic action or allergic reaction, resulting in abnormality of bile formation and excretion. Few effective therapies have become available for the treatment of cholestasis. Herein, we found that tectorigenin (TG), a natural isoflavone, showed definite protective effects on alpha-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury, significantly reversing the abnormality of plasma alanine/aspartate aminotransferase, total/direct bilirubin and alkaline phosphatase, as well as hepatic reactive oxygen species, catalase and superoxide dismutase. Importantly, the targeted metabolomic determination found that BA homeostasis could be well maintained in TG-treated cholestatic mice, especially the levels of glycocholic acid, tauromuricholic acid, taurocholic acid, taurolithocholic acid, tauroursodeoxycholic acid and taurodeoxycholic acid. Overall, primary/secondary and amidated/unamidated bile acid (BA) levels were significantly altered upon ANIT stimulation but could be restored by TG intervention to certain extents. In addition, TG boosted the expression of farnesoid x receptor (FXR), which in turn upregulated multidrug resistance protein 2 (MRP2) and bile salt export pump (BSEP) to accelerate the excretion of BA. Meanwhile, TG enhanced the expression of Nrf2 and its upstream genes PI3K/Akt and downstream target genes HO-1, NQO1, GCLC and GCLM to strengthen the antioxidant capacity. Taken together, TG plays a vital role in maintaining BA homeostasis and ameliorating cholestatic liver injury through regulating FXR-mediated BA efflux and Nrf2-mediated antioxidative pathways.

Novel Therapeutic Approaches for Mitigating Complications in Short Bowel Syndrome

Short bowel syndrome (SBS) is a particularly serious condition in which the small intestine does not absorb sufficient nutrients for biological needs, resulting in severe illness and potentially death if not treated. Given the important role of the gut in many signaling cascades throughout the body, SBS results in disruption of many pathways and imbalances in various hormones. Due to the inability to meet sufficient nutritional needs, an intravenous form of nutrition, total parental nutrition (TPN), is administered. However, TPN presents difficulties such as severe liver injury and altered signaling secondary to the continued lack of luminal contents. This manuscript aims to summarize relevant studies into the systemic effects of TPN on systems such as the gut-brain, gut-lung, and gut-liver axis, as well as present novel therapeutics currently under use or investigation as mitigation strategies for TPN induced injury.

Role of endoplasmic reticulum stress in impaired neonatal lung growth and bronchopulmonary dysplasia

Myeloperoxidase (MPO), oxidative stress (OS), and endoplasmic reticulum (ER) stress are increased in the lungs of rat pups raised in hyperoxia, an established model of bronchopulmonary dysplasia (BPD). However, the relationship between OS, MPO, and ER stress has not been examined in hyperoxia rat pups. We treated Sprague-Dawley rat pups with tunicamycin or hyperoxia to determine this relationship. ER stress was detected using immunofluorescence, transcriptomic, proteomic, and electron microscopic analyses. Immunofluorescence observed increased ER stress in the lungs of hyperoxic rat BPD and human BPD. Proteomic and morphometric studies showed that tunicamycin directly increased ER stress of rat lungs and decreased lung complexity with a BPD phenotype. Previously, we showed that hyperoxia initiates a cycle of destruction that we hypothesized starts from increasing OS through MPO accumulation and then increases ER stress to cause BPD. To inhibit ER stress, we used tauroursodeoxycholic acid (TUDCA), a molecular chaperone. To break the cycle of destruction and reduce OS and MPO, we used N-acetyl-lysyltyrosylcysteine amide (KYC). The fact that TUDCA improved lung complexity in tunicamycin- and hyperoxia-treated rat pups supports the idea that ER stress plays a causal role in BPD. Additional support comes from data showing TUDCA decreased lung myeloid cells and MPO levels in the lungs of tunicamycin- and hyperoxia-treated rat pups. These data link OS and MPO to ER stress in the mechanisms mediating BPD. KYC's inhibition of ER stress in the tunicamycin-treated rat pup's lung provides additional support for the idea that MPO-induced ER stress plays a causal role in the BPD phenotype. ER stress appears to expand our proposed cycle of destruction. Our results suggest ER stress evolves from OS and MPO to increase neonatal lung injury and impair growth and development. The encouraging effect of TUDCA indicates that this compound has the potential for treating BPD.

Ursodeoxycholic acid prevention on cholestasis associated with total parenteral nutrition in preterm infants: a randomized trial

BACKGROUND

Preterm infants with long-term parenteral nutrition (PN) therapy are at risk for cholestasis associated with total parenteral nutrition (PNAC). This study examined the safety and efficacy of ursodeoxycholic acid (UDCA) in preventing PNAC in preterm infants. Our research aimed to investigate the prophylactic effect of preventive oral UDCA on PNAC in preterm infants.

METHODS

We compared oral administration of UDCA prophylaxis with no prophylaxis in a randomized, open-label, proof-of-concept trial in preterm neonates with PN therapy. The low-birth-weight preterm infants (< 1800 g) who were registered to the neonatal intensive care unit (NICU) within 24 hours after birth were randomized. The main endpoint was the weekly values of direct bilirubin (DB) of neonates during the NICU stay.

RESULTS

Eventually, a total of 102 preterm neonates from January 2021 to July 2021 were enrolled in this prospective study (42 in the UDCA group and 60 in the control group). Notably, the peak serum level of DB [13.0 (12-16) vs. 15.2 (12.5-19.6) μmol/L, P < 0.05)] was significantly lower in the UDCA group than that in the control group without prevention. The peak serum level of total bilirubin (101.1 ± 34 vs. 116.5 ± 28.7 μmol/L, P < 0.05) was also significantly lower in the UDCA group than in the control group. Furthermore, the proportion of patients who suffered from neonatal cholestasis (0.0% vs. 11.7%, P < 0.05) in the UDCA group was significantly lower.

CONCLUSION

UDCA prophylaxis is beneficial in preventing PNAC in NICU infants receiving prolonged PN.

Direct hyperbilirubinemia and cholestasis in trisomy 13 and 18

Trisomy 13 and 18 are common chromosomal abnormalities that affect multiple organ systems. There is a paucity of published data, however, on the hepatic complications seen in these patient populations. One of the most common pathologic hepatobiliary issues seen in the newborn period is direct hyperbilirubinemia (DH). Thus, this study sought to estimate the incidence and evaluate possible etiologies of DH in neonates with trisomy 13 or 18. This retrospective cohort study included all infants admitted to our two neonatal intensive care units between 2012 and 2020 with the diagnosis of trisomy 13 or 18. DH is most commonly diagnosed as a direct bilirubin >1 mg/dl but a cutoff of >2 mg/dl is more specific for cholestasis, so both cutoffs were evaluated. Continuous data were compared using Fisher's exact test and categorical variables by the Mann-Whitney U test. Thirty-five patients met inclusion: 13 with trisomy 13 and 22 with trisomy 18. DH of >2 mg/dl was seen in seven (53.8%) patients with trisomy 13 and five (22.7%) with trisomy 18. Using a cutoff of >1 mg/dl, the rate of trisomy 13 was unchanged, but the rate in trisomy 18 increased to 9/22 (40.9%). There was a trend toward more DH in trisomy 13 patients (p = 0.079) versus trisomy 18 and higher rates in infants who received total parenteral nutrition (TPN) (50.0 vs. 13.3%, p = 0.026). The presence of cardiac or ultrasound-defined hepatobiliary abnormalities was not correlated with DH. Due to the high rates of DH in hospitalized neonates with trisomy 13 and 18, we recommend screening newborns with trisomy 13 or 18 for DH starting in the first week of life and continuing at least weekly until 4 weeks of life or until completion of TPN, whichever comes later. Future studies should further evaluate possible etiologies of DH in this population.

Tauroursodeoxycholic Acid Decreases Keloid Formation by Reducing Endoplasmic Reticulum Stress as Implicated in the Pathogenesis of Keloid

Keloids are a common form of pathologic wound healing and are characterized by an excessive production of extracellular matrix. This study examined the major contributing mechanism of human keloid pathogenesis using transcriptomic analysis. We identified the upregulation of mitochondrial oxidative stress response, protein processing in the endoplasmic reticulum, and TGF-β signaling in human keloid tissue samples compared to controls, based on ingenuity pathway and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Electron microscopic examinations revealed an increased number of dysmorphic mitochondria and expanded endoplasmic reticulum (ER) in human keloid tissue samples than that in controls. Western blot analysis performed using human tissues suggested noticeably higher ER stress signaling in keloids than in normal tissues. Treatment with tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, significantly decreased scar formation in rabbit models, compared to normal saline and steroid injections. In summary, our findings demonstrate the contributions of mitochondrial dysfunction and dysregulated ER stress signaling in human keloid formation and the potential of TUDCA in the treatment of keloids.

Tauroursodeoxycholic acid prevents Burkholderia pseudomallei-induced endoplasmic reticulum stress and is protective during melioidosis in mice

Background

Burkholderia pseudomallei, a facultative intracellular bacterium, is the aetiological agent of melioidosis that is responsible for up to 40% sepsis-related mortality in epidemic areas. However, no effective vaccine is available currently, and the drug resistance is also a major problem in the treatment of melioidosis. Therefore, finding new clinical treatment strategies in melioidosis is extremely urgent.

Results

We demonstrated that tauroursodeoxycholic acid (TUDCA), a clinically available endoplasmic reticulum (ER) stress inhibitor, can promote B. pseudomallei clearance both in vivo and in vitro. In this study, we investigated the effects of TUDCA on the survival of melioidosis mice, and found that treatment with TUDCA significantly decreased intracellular survival of B. pseudomallei. Mechanistically, we found that B. pseudomallei induced apoptosis and activated IRE1 and PERK signaling ways of ER stress in RAW264.7 macrophages. TUDCA treatment could reduce B. pseudomallei-induced ER stress in vitro, and TUDCA is protective in vivo.

Conclusion

Taken together, our study has demonstrated that B. pseudomallei infection results in ER stress-induced apoptosis, and TUDCA enhances the clearance of B. pseudomallei by inhibiting ER stress-induced apoptosis both in vivo and in vitro, suggesting that TUDCA could be used as a potentially alternative treatment for melioidosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02199-x.

Beta Cell Therapies for Preventing Type 1 Diabetes: From Bench to Bedside

Type 1 diabetes (T1D) is a chronic metabolic disease characterized by insulin deficiency, generally resulting from progressive autoimmune-mediated destruction of pancreatic beta cells. While the phenomenon of beta cell autoimmunity continues to be an active area of investigation, recent evidence suggests that beta cell stress responses are also important contributors to disease onset. Here we review the pathways driving different kinds of beta cell dysfunction and their respective therapeutic targets in the prevention of T1D. We discuss opportunities and important open questions around the effectiveness of beta cell therapies and challenges for clinical utility. We further evaluate ways in which beta cell drug therapy could be combined with immunotherapy for preventing T1D in light of our growing appreciation of disease heterogeneity and patient endotypes. Ultimately, the emergence of pharmacologic beta cell therapies for T1D have armed us with new tools and closing the knowledge gaps in T1D etiology will be essential for maximizing the potential of these approaches.

Impaired Gut-Systemic Signaling Drives Total Parenteral Nutrition-Associated Injury

BACKGROUND

Total parenteral nutrition (TPN) provides all nutritional needs intravenously. Although lifesaving, enthusiasm is significantly tempered due to side effects of liver and gut injury, as well as lack of mechanistic understanding into drivers of TPN injury. We hypothesized that the state of luminal nutritional deprivation with TPN drives alterations in gut-systemic signaling, contributing to injury, and tested this hypothesis using our ambulatory TPN model.

METHODS

A total of 16 one-week-old piglets were allocated randomly to TPN (n = 8) or enteral nutrition (EN, n = 8) for 3 weeks. Liver, gut, and serum were analyzed. All tests were two-sided, with a significance level of 0.05.

RESULTS

TPN resulted in significant hyperbilirubinemia and cholestatic liver injury, p = 0.034. Hepatic inflammation (cluster of differentiation 3 (CD3) immunohistochemistry) was higher with TPN (p = 0.021). No significant differences in alanine aminotransferase (ALT) or bile ductular proliferation were noted. TPN resulted in reduction of muscularis mucosa thickness and marked gut atrophy. Median and interquartile range for gut mass was 0.46 (0.30-0.58) g/cm in EN, and 0.19 (0.11-0.29) g/cm in TPN (p = 0.024). Key gut-systemic signaling regulators, liver farnesoid X receptor (FXR; p = 0.021), liver constitutive androstane receptor (CAR; p = 0.014), gut FXR (p = 0.028), G-coupled bile acid receptor (TGR5) (p = 0.003), epidermal growth factor (EGF; p = 0.016), organic anion transporter (OAT; p = 0.028), Mitogen-activated protein kinases-1 (MAPK1) (p = 0.037), and sodium uptake transporter sodium glucose-linked transporter (SGLT-1; p = 0.010) were significantly downregulated in TPN animals, whereas liver cholesterol 7 alpha-hydroxylase (CyP7A1) was substantially higher with TPN (p = 0.011).

CONCLUSION

We report significant alterations in key hepatobiliary receptors driving gut-systemic signaling in a TPN piglet model. This presents a major advancement to our understanding of TPN-associated injury and suggests opportunities for strategic targeting of the gut-systemic axis, specifically, FXR, TGR5, and EGF in developing ameliorative strategies.

Utility of liver biopsy in the evaluation of pediatric total parenteral nutrition cholestasis

BACKGROUND

Cholestasis is a serious complication of total parenteral nutrition (TPN) in neonates. Liver biopsies may be requested to assess the severity of cholestasis and fibrosis. We hypothesized that liver biopsy would not lead to changes in management or improved patient outcomes.

METHODS

A single institution retrospective review of infants with TPN cholestasis from January 2008 to January 2016.

OUTCOMES

length of stay, complications, change in management and mortality. Statistical analysis was performed using Fisher's exact test.

RESULTS

Twenty-seven out of 95 patients with TPN cholestasis underwent liver biopsy. Liver biopsy was associated with increased utilization or ursodeoxycholic acid (p = 0.001). There were no differences in length of stay (LOS) or mortality. One patient had a complication following anesthesia for liver biopsy, there were no bleeding complications recorded.

CONCLUSIONS

Liver biopsy in patients with TPN cholestasis was associated with an increase in utilization of ursodeoxycholic acid. The effects of this are not fully understood; however, liver biopsy was not associated with improved patient outcomes such as LOS or mortality.

Ursodeoxycholic acid versus phenobarbital for cholestasis in the Neonatal Intensive Care Unit

Background

Although neonates and young infants with cholestasis are commonly treated with either phenobarbital or ursodeoxycholic acid (ursodiol), there is no evidence that phenobarbital is effective for this indication. Our objective was to compare the effectiveness of ursodiol and phenobarbital for the treatment of cholestasis in a diverse NICU population.

Methods

This is a retrospective cohort study including infants with cholestasis who were admitted to a Level IV NICU between January 2010 and December 2015. Drug courses of phenobarbital and ursodiol were identified within the medical record, and medical, demographic, and drug information were extracted. The primary outcome was reduction in direct bilirubin.

Results

Sixty-eight infants provided a total of 112 courses of drug therapy for comparison. Diverse medical diagnoses were captured in the patient cohort. Ursodiol was significantly more effective in reducing direct bilirubin than was phenobarbital (− 1.89 vs + 0.76 mg/dL; − 33.33 vs + 13.0 umol/L, p-value 0.03), even after controlling for baseline cholestasis severity, intrauterine growth restriction status, and lipid lowering therapy (− 2.16 vs + 0.27 mg/dl; − 36.94 vs + 4.62 umol/L, p-value 0.03). There was no improvement in direct bilirubin in the majority of infants treated with phenobarbital.

Conclusions

Phenobarbital, as compared to ursodiol, has limited efficacy for the reduction of direct bilirubin in neonates and young infants with cholestasis. Given new data regarding the potential neurotoxicity of phenobarbital in the developing brain, providers may choose to avoid phenobarbital in the treatment of cholestasis in infants.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Tauroursodeoxycholic bile acid arrests axonal degeneration by inhibiting the unfolded protein response in X-linked adrenoleukodystrophy

The activation of the highly conserved unfolded protein response (UPR) is prominent in the pathogenesis of the most prevalent neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS), which are classically characterized by an accumulation of aggregated or misfolded proteins. This activation is orchestrated by three endoplasmic reticulum (ER) stress sensors: PERK, ATF6 and IRE1. These sensors transduce signals that induce the expression of the UPR gene programme. Here, we first identified an early activator of the UPR and investigated the role of a chronically activated UPR in the pathogenesis of X-linked adrenoleukodystrophy (X-ALD), a neurometabolic disorder that is caused by ABCD1 malfunction; ABCD1 transports very long-chain fatty acids (VLCFA) into peroxisomes. The disease manifests as inflammatory demyelination in the brain or and/or degeneration of corticospinal tracts, thereby resulting in spastic paraplegia, with the accumulation of intracellular VLCFA instead of protein aggregates. Using X-ALD mouse model (Abcd1⁻ and Abcd1⁻/Abcd2^−/− mice) and X-ALD patient’s fibroblasts and brain samples, we discovered an early engagement of the UPR. The response was characterized by the activation of the PERK and ATF6 pathways, but not the IRE1 pathway, showing a difference from the models of AD, PD or ALS. Inhibition of PERK leads to the disruption of homeostasis and increased apoptosis during ER stress induced in X-ALD fibroblasts. Redox imbalance appears to be the mechanism that initiates ER stress in X-ALD. Most importantly, we demonstrated that the bile acid tauroursodeoxycholate (TUDCA) abolishes UPR activation, which results in improvement of axonal degeneration and its associated locomotor impairment in Abcd1⁻/Abcd2^−/− mice. Altogether, our preclinical data provide evidence for establishing the UPR as a key drug target in the pathogenesis cascade. Our study also highlights the potential role of TUDCA as a treatment for X-ALD and other axonopathies in which similar molecular mediators are implicated.

Increased monocyte-derived reactive oxygen species in type 2 diabetes: role of endoplasmic reticulum stress

NEW FINDINGS

What is the central question of this study? Patients with type 2 diabetes exhibit increased oxidative stress in peripheral blood mononuclear cells, including monocytes; however, the mechanisms remain unknown. What is the main finding and its importance? The main finding of this study is that factors contained within the plasma of patients with type 2 diabetes can contribute to increased oxidative stress in monocytes, making them more adherent to endothelial cells. We show that these effects are largely mediated by the interaction between endoplasmic reticulum stress and NADPH oxidase activity. Recent evidence suggests that exposure of human monocytes to glucolipotoxic media to mimic the composition of plasma of patients with type 2 diabetes (T2D) results in the induction of endoplasmic reticulum (ER) stress markers and formation of reactive oxygen species (ROS). The extent to which these findings translate to patients with T2D remains unclear. Thus, we first measured ROS (dihydroethidium fluorescence) in peripheral blood mononuclear cells (PBMCs) from whole blood of T2D patients (n = 8) and compared the values with age-matched healthy control subjects (n = 8). The T2D patients exhibited greater basal intracellular ROS (mean ± SD, +3.4 ± 1.4-fold; P < 0.05) compared with control subjects. Next, the increase in ROS in PBMCs isolated from T2D patients was partly recapitulated in cultured human monocytes (THP-1 cells) exposed to plasma from T2D patients for 36 h (+1.3 ± 0.08-fold versus plasma from control subjects; P < 0.05). In addition, we found that increased ROS formation in THP-1 cells treated with T2D plasma was NADPH oxidase derived and led to increased endothelial cell adhesion (+1.8 ± 0.5-fold; P < 0.05) and lipid uptake (+1.3 ± 0.3-fold; P < 0.05). Notably, we found that T2D plasma-induced monocyte ROS and downstream functional effects were abolished by treating cells with tauroursodeoxycholic acid, a chemical chaperone known to inhibit ER stress. Collectively, these data indicate that monocyte ROS production with T2D can be attributed, in part, to signals from the circulating environment. Furthermore, an interplay between ER stress and NADPH oxidase activity contributes to ROS production and may be a mechanism mediating endothelial cell adhesion and foam cell formation in T2D.

Parenteral Nutrition–Associated Cholestasis in Neonates: Multivariate Analysis of the Potential Protective Effect of Taurine

BACKGROUND

Neonates receiving parenteral nutrition (PN) are at risk for PN-associated cholestasis (PNAC); however, no preventive factors for PNAC have been clearly identified. Despite reports suggesting that taurine may prevent PNAC in neonates, such an effect of taurine has not yet been definitively demonstrated. We determined whether taurine supplementation reduces the incidence of PNAC in premature or critically ill neonates.

METHODS

This study was part of a prospective, randomized, multi-institutional trial designed to assess cholecystokinin vs placebo as a potential preventive therapy of PNAC. Taurine supplementation of PN varied between institutions. The presence or absence of taurine in PN was analyzed by multivariate analysis, with a primary outcome measure of serum conjugated bilirubin (CB) as a measure of PNAC.

RESULTS

Taurine reduced PNAC in premature infants (estimated maximum CB [95% confidence interval] 0.50 mg/dL [-0.17 to 1.18] for those receiving taurine, vs 3.45 mg/dL [1.79-5.11] for neonates not receiving taurine, approaching significance, p = .07). Taurine significantly reduced PNAC in infants with necrotizing enterocolitis (NEC; estimated maximum CB 4.04 mg/dL [2.85-5.23], NEC infants receiving taurine, vs 8.29 mg/dL [5.61-10.96], NEC infants not receiving taurine, p < .01). There were too few neonates with surgical anomalies to evaluate the effect of taurine in this group.

CONCLUSIONS

Within specific subgroups of neonatal patients, taurine supplementation does offer a very significant degree of protection against PNAC. Patients with NEC or severe prematurity are most likely to benefit substantially from taurine supplementation.

Controversies in the Mechanism of Total Parenteral Nutrition Induced Pathology

Over 30,000 patients are permanently dependent on Total Parenteral Nutrition (TPN) for survival with several folds higher requiring TPN for a prolonged duration. Unfortunately, it can cause potentially fatal complications. TPN infusion results in impairment of gut mucosal integrity, enhanced inflammation, increased cytokine expression and trans-mucosal bacterial permeation. It also causes endotoxin associated down regulation of bile acid transporters and Parenteral Nutrition Associated Liver Disease (PNALD), which includes steatosis, disrupted glucose metabolism, disrupted lipid metabolism, cholestasis and liver failure. Despite multiple theories, its etiology and pathophysiology remains elusive and is likely multifactorial. An important cause for TPN related pathologies appears to be a disruption in the normal enterohepatic circulation due to a lack of feeding during such therapy. This is further validated by the fact that in clinical settings, once cholestasis sets in, its reversal occurs when a patient is receiving a major portion of calories enterally. There are several other postulated mechanisms including gut bacterial permeation predisposing to endotoxin associated down regulation of bile acid transporters. An additional potential mechanism includes toxicity of the TPN solution itself, such as lipid mediated hepatic toxicity. Prematurity, leading to a poor development of bile acid regulating nuclear receptors and transporters has also been implicated as a causative factor. This review presents the current controversies and research into mechanisms of TPN associated injury.

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?

Impact of standardized feeding guidelines on enteral nutrition administration, growth outcomes, metabolic bone disease, and cholestasis in the NICU

OBJECTIVES

The objectives of this study were to determine whether the implementation of standardized feeding guidelines (SFGs) in a neonatal intensive care unit had an impact on the administration of enteral nutrition, growth, and bone and liver health.

METHODS

This was a retrospective chart review of infants ≤ 32 weeks' gestation and ≤ 1500 g at birth who received enteral nutrition either via traditional care (TC) or via SFGs. The outcomes of the study were to determine the day of life the first enteral feedings were started, the day of life full, fortified enteral feedings were established, the day of life the infant returned to birth weight, the change in weight z score from birth to day of life 30, and the presence of metabolic bone disease and cholestasis.

RESULTS

There were 128 infants in the TC group and 125 infants in the SFG group. Based on the Cox regression, no significant differences were found between the 2 groups in the length of time to the first feed (P=0.110; CI 1.03-1.70), in the length of time to full, fortified enteral feedings (P=0.334; CI 0.87-1.44), in the length of time to return to birth weight (P=0.545; CI 0.77-1.28), incidence of metabolic bone disease (P=0.990), or incidence of cholestasis (P=0.926).

CONCLUSIONS

This study provides preliminary evidence that SFGs have an effect on enteral nutrition administration, growth, and morbidity for preterm infants. Although the findings were not statistically significant, they are clinically relevant.

ER stress and hepatic lipid metabolism

The endoplasmic reticulum (ER) is an important player in regulating protein synthesis and lipid metabolism. Perturbation of ER homeostasis, referred as “ER stress,” has been linked to numerous pathological conditions, such as inflammation, cardiovascular diseases, and metabolic disorders. The liver plays a central role in regulating nutrient and lipid metabolism. Accumulating evidence implicates that ER stress disrupts lipid metabolism and induces hepatic lipotoxicity. Here, we review the major ER stress signaling pathways, how ER stress contributes to the dysregulation of hepatic lipid metabolism, and the potential causative mechanisms of ER stress in hepatic lipotoxicity. Understanding the role of ER stress in hepatic metabolism may lead to the identification of new therapeutic targets for metabolic diseases.

Parenteral nutrition-associated liver disease: a retrospective study of ursodeoxycholic Acid use in neonates

OBJECTIVES

To verify the effect of ursodeoxycholic acid (UDCA) on the duration of neonatal parenteral nutrition-associated liver disease.

METHODS

Retrospective cohort study of neonates in intensive care between 2004 and 2007 presenting with parenteral nutrition-associated liver disease.

RESULTS

Of 118 eligible infants, 64 received UDCA. Cholestasis lasted longer in the UDCA group (79 vs. 50 days, p=0.001). However, treatment was delayed for a median of 24 days after cholestasis onset. Multivariate Cox regression analysis showed no association between UDCA and cholestasis duration. The rate of decline of conjugated bilirubin was greater in treated patients (median 0.084 mg/dL/day vs. 0.60 mg/dL/day; p=0.009) and weight gain was greater (22.8 vs. 17.7 g/kg/day, p=0.010).

CONCLUSIONS

UDCA therapy was not associated with the duration of parenteral nutrition-associated liver disease. A delay in treatment initiation might explain this result. UDCA therapy was associated with a faster decline of conjugated bilirubin and greater weight gain.

Incidence, prevention, and treatment of parenteral nutrition-associated cholestasis and intestinal failure-associated liver disease in infants and children: a systematic review

BACKGROUND

Cholestasis is a significant life-threatening complication in children on parenteral nutrition (PN). Strategies to prevent/treat PN-associated cholestasis (PNAC) and intestinal failure-associated liver disease (IFALD) have reached moderate success with little supporting evidence. Aims of this systematic review were (1) to determine the incidence of PNAC/IFALD in children receiving PN for ≥ 14 days and (2) to review the efficacy of measures to prevent/treat PNAC/IFALD.

METHODS

Of 4696 abstracts screened, 406 relevant articles were reviewed, and studies on children with PN ≥ 14 days and cholestasis (conjugated bilirubin ≥ 2 mg/dL) were included. Analyzed parameters were (1) PNAC/IFALD incidence by decade and by PN length and (2) PNAC/IFALD prevention and treatment (prospective studies).

RESULTS

Twenty-three articles (3280 patients) showed an incidence of 28.2% and 49.8% of PNAC and IFALD, respectively, with no evident alteration over the last decades. The incidence of PNAC was directly proportional to the length of PN (from 15.7% for PN ≤ 1 month up to 60.9% for PN ≥ 2 months; P < .0001). Ten studies on PNAC met inclusion criteria. High or intermediate-dose of oral erythromycin and aminoacid-free PN with enteral whey protein gained significant benefits in preterm neonates (P < .05, P = .003, and P < .001, respectively). None of the studies reviewed met inclusion criteria for treatment.

CONCLUSIONS

The incidence of PNAC/IFALD in children has no obvious decrease over time. PNAC is directly correlated to the length of PN. Erythromycin and aminoacid-free PN with enteral whey protein have shown to prevent PNAC in preterm neonates. There is a lack of high-quality prospective studies, especially on IFALD.

Pathogenesis and treatment of parenteral nutrition-associated liver disease

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) has been common in patients who require long-term parenteral nutrition. PNALD develops in 40%-60% of infants on long-term parenteral nutrition compared with 15%-40% of adults on home parenteral nutrition for intestinal failure. The pathogenesis of PNALD is multifactorial and remains unclear. There is no specific treatment. Management strategies for its prevention and treatment depend on an understanding of many risk factors. This review aims to provide an update on the pathogenesis and treatment of this disease.

DATA SOURCES

A literature search was performed on the MEDLINE and Web of Science databases for articles published up to October 2011, using the keywords: parenteral nutrition associated liver disease, intestinal failure associated liver disease, lipid emulsions and fish oil. The available data reported in the relevant literatures were analyzed.

RESULTS

The literature search provided a huge amount of evidence about the pathogenesis and management strategies on PNALD. Currently, lack of enteral feeding, extended duration of parenteral nutrition, recurrent sepsis, and nutrient deficiency or excess may play important roles in the pathogenesis of PNALD. Recent studies found that phytosterols, present as contaminants in soy-based lipid emulsions, are also an important factor in the pathogenesis. Moreover, the treatment of PNALD is discussed.

CONCLUSIONS

The use of lipid emulsions, phytosterols in particular, is associated with PNALD. Management strategies for the prevention and treatment of PNALD include consideration of early enteral feeding, the use of specialized lipid emulsions such as fish oil emulsions, and isolated small bowel or combined liver and small bowel transplantation. A greater understanding of the pathogenesis of PNALD has led to promising interventions to prevent and treat this condition. Future work should aim to better understand the mechanisms of PNALD and the long-term outcomes of its treatment.

Medical update and potential advances in the treatment of pediatric intestinal failure

Short bowel syndrome (SBS) and intestinal failure are chronic malabsorption disorders with considerable nutritional and growth consequences in children. Intestinal failure occurs when the functional gastrointestinal mass is reduced even if there is normal anatomical gastrointestinal length. A number of management strategies are often utilized to achieve successful intestinal rehabilitation and maintain adequate nutrition to avoid intestinal transplant. These strategies include minimizing the effect of parenteral associated liver disease, limiting catheter complications, and treating bacterial overgrowth in the remaining small intestine. In addition, there continues to be significant research interest in enhancing intestinal adaptation with targeted therapies. The purpose of this review is to discuss current perspectives and to highlight recent medical advances in novel investigational therapies.

TUDCA slows retinal degeneration in two different mouse models of retinitis pigmentosa and prevents obesity in Bardet-Biedl syndrome type 1 mice

PURPOSE

To evaluate and compare the protective effect of tauroursodeoxycholic acid (TUDCA) on photoreceptor degeneration in different models of retinal degeneration (RD) in mice.

METHODS

Bbs(M390R/M390R) mice were injected subcutaneously twice a week, from P40 to P120, and rd10 mice were injected every 3 days from P6 to P38 with TUDCA or vehicle (0.15 M NaHCO(3)). Rd1 and rd16 mice were injected daily from P6 to P30 with TUDCA or vehicle. Retinal structure and function were determined at multiple time points by electroretinography (ERG), optical coherence tomography (OCT), and histology.

RESULTS

The amplitude of ERG b-waves was significantly higher in TUDCA-treated Bbs1 and rd10 animals than in controls. Retinal thickness on OCT was slightly greater in treated Bbs1 animals than in the controls. Histologically, outer segments were preserved, and the outer nuclear layer was significantly thicker in the treated Bbs1 and rd10 mice than in the controls. Bbs1(M390R/M390R) mice developed less obesity than the control Bbs1(M390R/M390R) while receiving TUDCA. The Rd1 and rd16 mice showed no improvement with TUDCA treatment, and the rd1 mice did not have normal weight gain during treatment.

CONCLUSIONS

TUDCA treatment preserved ERG b-waves and the outer nuclear layer in Bbs1(M390R/M390R) mice, and prevented obesity assessed at P120. TUDCA treatment preserved ERG b-waves and the outer nuclear layer in the rd10 mice to P30. TUDCA is a prime candidate for treatment of humans with retinal degeneration, especially those with Bardet-Biedl syndrome, whom it may help not only with the vision loss, but with the debilitating obesity as well.

Parenteral nutrition-associated cholestasis: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review

OBJECTIVE

The aim of this study was to review evidence-based data addressing key clinical questions regarding parenteral nutrition-associated cholestasis (PNAC) and parenteral nutrition-associated liver disease (PNALD) in children.

DATA SOURCE

Data were obtained from PubMed, Medicine databases of the English literature (up to October 2010), and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

The review of PNAC/PNALD has been divided into 4 areas to simplify one's understanding of the current knowledge regarding the pathogenesis and treatment of this disease: (1) nonnutrient risk factors associated with PNAC, (2) PNAC and lipid emulsions, (3) nutritional (nonlipid) considerations in the prevention of PNAC, and (4) supplemental medications in the prevention and treatment of PNAC.

RESULTS

The data for each topic area relevant to the clinical practice of pediatric surgery were reviewed, evaluated, graded, and summarized.

CONCLUSIONS

Although the conditions of PNAC and PNALD have been well recognized for more than 30 years, only a few concrete associations and treatment protocols have been established.

Systematic review: medical and nutritional interventions for the management of intestinal failure and its resultant complications in children

BACKGROUND

Intestinal failure (IF) affects a growing number of children due to increasing numbers of preterm infants surviving intestinal resection for necrotising enterocolitis and improving surgical techniques for congenital gut anomalies. Parenteral nutrition (PN) is the mainstay of therapy; enteral nutrition may have trophic effects on the gut.

AIM

To review systematically evidence for the effectiveness of medical and nutritional interventions in the treatment of IF in children.

METHODS

Retrieval of data from studies of patients aged <18 years and receiving >28 days of PN. Outcome measures were improvement in intestinal function, intestinal adaptation, growth, prevention and treatment of IF-associated liver disease, and mortality. Cochrane Database (November 2009), MEDLINE (1950-November 2009) and CINAHL (1982-November 2009) electronic database searches were made using keyword and subject headings (MeSH): IF, Short Bowel Syndrome (SBS), PN and Child. The level of the evidence (EL) was assessed using SIGN (Scottish Intercollegiate Guidelines Network) methodology (http://www.sign.ac.uk).

RESULTS

From 1 607 620 hits, 720 abstracts were reviewed. Thirty-three original articles were included. No studies were of high methodological quality.

CONCLUSIONS

The evidence base for medical and nutritional interventions in paediatric IF is limited and of poor quality. In the absence of randomised-controlled trials, this evidence base can improve through case control and cohort research; and with better multiagency communication, the study of inter-centre differences is possible. Achievable short-term goals would include the study of: optimal ursodeoxycholic usage, novel intralipid formulations, cycled enteral antibiotics, enteral probiotics and new enteral feeding strategies.

Synergy of combined doxycycline/TUDCA treatment in lowering Transthyretin deposition and associated biomarkers: studies in FAP mouse models

Familial Amyloidotic Polyneuropathy (FAP) is a disorder characterized by the extracellular deposition of fibrillar Transthyretin (TTR) amyloid, with a special involvement of the peripheral nerve. We had previously shown that doxycycline administered for 3 months at 40 mg/Kg/ml in the drinking water, was capable of removing TTR amyloid deposits present in stomachs of old TTR-V30M transgenic mice; the removal was accompanied by a decrease in extracellular matrix remodeling proteins that accompany fibrillar deposition, but not of non-fibrillar TTR deposition and/or markers associated with pre-fibrillar deposits. On the other hand, Tauroursodeoxycholic acid (TUDCA), a biliary acid, administrated to the same mouse model was shown to be effective at lowering deposited non-fibrillar TTR, as well as the levels of markers associated with pre-fibrillar TTR, but only at young ages.

In the present work we evaluated different doxycycline administration schemes, including different periods of treatment, different dosages and different FAP TTR V30M animal models. Evaluation included CR staining, immunohistochemistry for TTR, metalloproteinase 9 (MMP-9) and serum amyloid P component (SAP). We determined that a minimum period of 15 days of treatment with a 8 mg/Kg/day dosage resulted in fibril removal. The possibility of intermittent treatments was also assessed and a maximum period of 15 days of suspension was determined to maintain tissues amyloid-free. Combined cycled doxycycline and TUDCA administration to mice with amyloid deposition, using two different concentrations of both drugs, was more effective than either individual doxycycline or TUDCA, in significantly lowering TTR deposition and associated tissue markers. The observed synergistic effect of doxycycline/TUDCA in the range of human tolerable quantities, in the transgenic TTR mice models prompts their application in FAP, particularly in the early stages of disease.

Parenteral nutrition-associated cholestasis in premature babies: risk factors and predictors

BACKGROUND

One of the most common complications in infants under parenteral nutrition treatment is parenteral nutrition-associated cholestasis (PNAC). The etiology of PNAC is thought to be multifactorial. The aims of this study were to evaluate the risk factors for PNAC in our neonatal intensive care unit and determine useful predictors.

METHODS

This study enrolled premature infants (gestational age <36 weeks) who were admitted to our neonatal intensive care unit and treated with parenteral nutrition infusion for at least 2 weeks between January 2004 and January 2007. Multiple possible risk factors were analyzed by a retrospective review study design. PNAC was defined as direct bilirubin greater than 1.5 mg/dL during parenteral nutrition.

RESULTS

A total of 62 premature infants with prolonged course of parenteral nutrition were eligible for this study; 11 (17.74%) of the infants developed PNAC. There were significant differences in terms of gestational age, birth body weight, duration of parenteral nutrition, septic episodes, and average energy intake during the 2nd and 3rd weeks of life between infants with cholestasis and those without cholestasis. Of these risk factors, the duration of parenteral nutrition was most significant after multivariate logistic regression analysis.

CONCLUSION

Young gestational age, low birth body weight, more sepsis episodes, and long duration of parenteral nutrition were significant risk factors for PNAC in our study. Low energy intake during the 2nd and 3rd weeks of life is a predictor for PNAC.

High rates of mortality and morbidity occur in infants with parenteral nutrition-associated cholestasis

BACKGROUND

Extremely few data are available about the natural history of parenteral nutrition (PN)-associated cholestasis. The authors evaluated a cohort of infants at a large center to determine the outcome of PN-associated cholestasis in infants with some gastrointestinal function.

METHODS

The authors reviewed the records of all infants admitted to a level 3 neonatal intensive care unit over a 16-month period who had the diagnosis of PN-associated cholestasis. Records were reviewed in these infants for course of cholestasis, laboratory values, outcome, and infection rate.

RESULTS

Sixty-six patients were admitted who met the study criteria. There were 10 deaths and 1 referral for liver transplant (Death/TPlant) (17%) in the first year of life. All Death/TPlant infants had at least 1 positive blood culture after the onset of cholestasis. Maximum conjugated bilirubin (MaxCB) in Death/TPlant infants was 15.7 +/- 2.2 (SEM) compared to 8.4 +/- 1.0 mg/dL in babies who recovered. Of 21 infants with a MaxCB > or =10.0, Death/TPlant occurred in 8/21 (38%). Of 40 babies with positive blood cultures, 11 were in the Death/TPlant group vs no deaths among the 25 without positive blood cultures. Average time to resolution from the MaxCB to a CB <2.0 mg/dL was 66 +/- 7 days (n = 49).

CONCLUSIONS

Infants with PN-associated cholestasis have high rates of mortality despite the presence of some gastrointestinal function. These data support further evaluation and the development of novel forms of therapy for babies with parenteral-associated CB > or =2 mg/dL with emphasis on interventions for infants with a CB >10 mg/dL.

[Cholestasis associated with prolonged parenteral nutrition in neonates: the role of urso-deoxycholic acid]

INTRODUCTION

The morbidity associated with prematurity occasionally leads to the use of prolonged parenteral nutrition, with the subsequent development of cholestasis being one of its complications.

PATIENTS AND METHODS

This is a two year retrospective study which compared biochemical markers of liver damage and cholestasis in premature babies who received or did not receive urso-deoxycholic acid for parenteral nutrition associated cholestasis.

RESULTS

Of a total of 24 recruited patients 17 received urso-deoxycholic acid and 7 did not. In the treated group significant decreases (P<0.05) in gamma-glutamyltranspeptidase and conjugated bilirubin were found after four and five weeks of treatment, respectively. Moreover, a significant correlation (P<0.01) between conjugated bilirubin and duration of total parenteral nutrition was established.

CONCLUSIONS

Patients who were promptly treated with urso-deoxycholic acid showed a more rapid decrease in biochemical markers of cholestasis, but not of cytotoxicity in the hepatobiliary complications secondary to prolonged parenteral nutrition. However, the present study has limitations derived from its design and therefore it would be desirable launch a randomized trial with sufficient power to evaluate the benefits derived from prophylactic or therapeutic use of urso-deoxycholic acid in the hepatobiliary conditions associated with the prolonged use of parenteral nutrition in the premature infants.

Neonatal nutrition: a brief review

BACKGROUND

With increasing survival of extremely premature infants, emphasis is now focused on the quality of these survivors' lives. Possibly the most important factor in the premature's ability to survive in the NICU and thrive is the ability to replicate in utero growth through enteral and parenteral nutrition.

DATA SOURCES

Current literature and review articles were retrieved from PubMed and personal files of the authors.

RESULTS

The use and complications of the various components of total parenteral nutrition (TPN) were reviewed. The composition of appropriate enteral feeds for the premature was reviewed as was the difficulties associated with the establishment of adequate enteral feeds in the premature infants.

CONCLUSIONS

Early initiation of amino acids in TPN and timely increases in the components of TPN can improve the caloric intake of prematures. Enteral feeds, particularly of breast milk, may be started within the first few days of life in all but hemodynamically unstable prematures. Newer lipid preparations show promise in reversing the hepatic damage of TPN associated cholestatic jaundice.

Percutaneous cholangiography for the treatment of parenteral nutrition-associated cholestasis in surgical neonates: preliminary experience

OBJECTIVE

Parenteral nutrition-associated cholestasis (PNAC) occurs in up to 60% of surgical neonates with intestinal failure, and 10% will develop end-stage liver failure. Our aim was to evaluate the effectiveness of percutaneous transhepatic transcholecystic cholangiography (PTTC) in the treatment of PNAC in surgical neonates.

METHODS

A retrospective double cohort study of surgical neonates with PNAC was conducted. Patients with PNAC who received PTTC were compared to controls matched by gestational age, birth weight, sex, and parenteral nutrition duration. Percutaneous transhepatic transcholecystic cholangiography was performed under general anesthesia with ultrasound guidance. Analysis was performed using paired Student's t test and McNemar chi2 test.

RESULTS

Nine PTTC patients and 9 controls were similar in mean age (35.5 +/- 3.1 vs 35.6 +/- 4.2 weeks, P = .85), birth weight (2531 +/- 879 vs 2692 +/- 1052 g, P = .28), sex (all males), and parenteral nutrition duration (51.2 +/- 29.8 vs 53.3 +/- 33.3 days, P = .74). Percutaneous transhepatic transcholecystic cholangiography was performed in 9 patients at mean corrected age of 5.5 +/- 3.4 weeks and weight of 3621 +/- 546 g. All control patients and 8 (88.9%) of 9 PTTC patients had eventual resolution of hyperbilirubinemia. Percutaneous transhepatic transcholecystic cholangiography patients experienced a more rapid rate of resolution of their cholestasis, and the mean time to resolution of conjugated bilirubin was less in the PTTC group (8.5 +/- 3.2 vs 18.5 +/- 7.6 weeks, P = .02).

CONCLUSION

Therapeutic PTTC results in a 50% reduction in the time to PNAC resolution. Percutaneous transhepatic transcholecystic cholangiography may have a role as active therapy to slow progression of PNAC in surgical neonates with intestinal failure.

Mechanisms of disease: update on the molecular etiology and fundamentals of parenteral nutrition associated cholestasis

Since its introduction into clinical practice, parenteral nutrition has revolutionized the care of premature neonates. Serum transaminase and bilirubin levels are commonly elevated in infants on parenteral nutrition, but their normalization is typical in the setting of short-term administration of parenteral nutrition uncomplicated by sepsis. Premature infants who require long-term parenteral nutrition are, however, at severe risk for developing life-threatening hepatic complications. These complications include cirrhosis, liver failure, and the concomitant risks of sepsis, coagulopathy and death. Premature infants and those with short-bowel syndrome are most susceptible to these morbid outcomes. Although it has been more than a quarter of a century since parenteral nutrition was first introduced and its association with hepatic complications described, the precise etiology of parenteral nutrition associated cholestasis (PNAC) remains a mystery; however, our understanding of the molecular components that contribute to PNAC has improved substantially. In this Review, we summarize the fundamentals of PNAC, describe animal models of the disease, review the hepatic bile acid transporters that are crucial for bile acid homeostasis, and define the roles that endotoxin, genetics, and the components of parenteral nutrition are likely to have in the molecular pathogenesis of this life-threatening condition.

Identifying patients, on the first day of life, at high-risk of developing parenteral nutrition-associated liver disease

BACKGROUND

Prolonged use of parenteral nutrition (PN) in neonates can lead to parenteral nutrition-associated liver disease (PNALD), manifested by elevated direct bilirubin concentrations, and in some cases progressing to hepatic failure. When new potential means of preventing PNALD in the neonatal intensive care unit (NICU), such as Omegaven usage, are tested in clinical trials, the studies should enroll neonates at a very high risk of developing PNALD. However, it is not always clear, in the first days of life, which neonates are most likely to develop PNALD. Therefore, preparatory to devising studies of prophylaxis against PNALD, we conducted an evaluation of all NICU patients who received PN for >or=14 day, assessing their likelihood of developing PNALD.

METHODS

We performed an historic cohort analysis of all neonates in the Intermountain Healthcare system, receiving PN for 14 days or more during their stay, with dates of birth between 1 January, 2002 and 30 June, 2006.

RESULTS

During the 4(1/2)-year period, 9861 neonates were cared for in the Intermountain Healthcare NICUs. Of these, 9547 (96.8%) survived for at least 28 days, and of these 6543 (68.5%) received PN. Twenty-one percent (1366 patients) of those receiving PN, received it for >or=14 days. PNALD was ascertained in this group by a direct bilirubin >or=2.0 mg/dl. Neonates receiving PN for 14-28 days had a 14% incidence of PNALD, those receiving PN for 29-56 days had a 43% incidence, those receiving PN for 57-100 days had a 72% incidence and those receiving PN for >100 days had a 85% incidence. Groups of patients identifiable on the first day of life as having the highest risk of developing PNALD were birth weight <500 g (odds ratio (OR), 30.7), birth weight 500-749 g (OR, 13.1), gastrochisis (OR, 20.3) and jejunal atresia (OR, 24.0). Among 357 patients who developed PNALD, the highest direct bilirubin concentrations correlated with the highest serum alkaline phosphatase and transaminase concentrations. Deaths after 28 days were much more common in those with the highest direct bilirubin and transaminase concentrations (P<0.0001).

CONCLUSIONS

In the first days of life, certain NICU patients can be identified as being at very high risk for developing PNALD. These are patients <750 g birth weight, those with gastrochisis and those with jejunal atresia. We speculate that these groups would be reasonable subjects for including in a PNALD prophylaxis trial, testing new preventative strategies such as Omegaven usage.

Ultrasound-guided percutaneous cholecystostomy for acute neonatal biliary obstruction

Use of a percutaneously-inserted cholecystostomy drainage tube is an effective therapeutic option for acute hyperbilirubinemia in severely-ill adult patients, but to our knowledge has not been previously reported in infants. We describe an infant who developed acute extrahepatic biliary tract obstruction with marked conjugated (direct) hyperbilirubinemia, and who was determined to be an unsuitable surgical candidate. Ultrasound-guided percutaneous cholecystostomy was performed and resulted in prompt, significant, and sustained decline in serum bilirubin levels. Potential risks and benefits, as well as suggested indications for the procedure are discussed.

Early treatment with ursodeoxycholic acid for cholestasis in children on parenteral nutrition because of primary intestinal failure

BACKGROUND

There is conflicting evidence as to whether ursodeoxycholic acid (UDCA) reduces the incidence of parenteral nutrition-associated cholestasis.

AIM

To investigate the efficacy of UDCA on parenteral nutrition-associated cholestasis in children with intestinal failure due to short bowel syndrome or to other causes.

METHODS

Children with cholestasis received 30 mg/kg/day UDCA. Improvement or normalization of parenteral nutrition-associated cholestasis was evaluated at 6 months of therapy and at the last follow-up. In a subgroup of children, serum UDCA levels were measured while receiving UDCA and after 4 weeks withdrawal.

RESULTS

Twelve children were treated with UDCA. Full remission or partial improvement of parenteral nutrition-associated cholestasis occurred in 11 of 12 children. In three of four children, withdrawal of UDCA was associated with a rebound rise of cholestasis. Only one of 12 treated children showed no improvement and in this patient, in contrast to four other patients, plasma levels of UDCA did not increase during treatment.

CONCLUSIONS

Ursodeoxycholic acid was effective in controlling parenteral nutrition-associated cholestasis. The efficacy of UDCA also in children with short bowel is related to intestinal absorption.

Total Parenteral Nutrition: Challenges and Practice in the Cirrhotic Patient

Patients with cirrhosis develop metabolic derangements of protein, carbohydrate, and lipid metabolism. Malnutrition is commonplace and is associated with morbidity and mortality. Specific nutrient deficiencies may occur and enteral or parenteral nutritional support may improve outcome in appropriately selected patients. Parenteral nutrition itself has been associated with hepatic dysfunction, although the preponderance of evidence suggests that hepatic dysfunction is more a function of the underlying disorder and malabsorption. Intravenously infused organic nutrients may be metabolized differently than the same nutrient consumed enterally. The pathophysiology of total parenteral nutrition-associated liver disease is discussed as well as potential management options.

Ursodeoxycholic Acid for the Treatment of Parenteral Nutrition–Associated Cholestasis in Pediatric Patients

Objective:

To determine the relative safety and efficacy of ursodeoxycholic acid (UDCA) in children and neonates with parenteral nutrition–associated cholestasis (PNAC).

Data Sources:

A comprehensive search (up to May 29, 2006) of the following databases was conducted to identify relevant prospective, randomized, double-blind clinical trials and systematic reviews: Ovid–MEDLINE, PubMed, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Abstracts of Reviews of Effects, and the Centre for Reviews and Dissemination. In addition, reference lists from retrieved articles were searched to identify trials or systematic reviews not identified in the search of electronic databases. Also, the manufacturer of UDCA was contacted regarding access to any other unpublished trials that could be included in this review.

Study Selection and Data Extraction:

Prospective, double-blind, randomized, controlled trials of neonates (<36 wk gestational age) and/or children (0–18 y) who developed PNAC while receiving parenteral nutrition were included in the analysis. Articles were evaluated with specific focus placed on the following hierarchy of outcomes: mortality, nonfatal serious adverse events, liver failure, infection, sepsis, return of liver function test results to within normal ranges, and relief of pruritus.

Data Synthesis:

No prospective, double-blind, randomized, controlled trials assessing the efficacy and safety of UDCA for the treatment of PNAC in children and/or neonates were identified. Five retrospective chart reviews and/or case series were identified; however, the results of these studies were conflicting and do not provide sufficient evidence of the safety and efficacy of UDCA for the treatment of PNAC.

Conclusions:

There is no evidence from prospective, double-blind, randomized, controlled trials in neonates and/or children with PNAC regarding the relative safety and efficacy of UDCA therapy.

Short bowel syndrome and intestinal transplantation in children

PURPOSE OF REVIEW

This review summarizes recent knowledge and clinical practice for pediatric patients suffering extensive intestinal resection causing short bowel syndrome. This condition requires the use of parenteral nutrition, as long as intestinal failure persists, and may be, in some selected cases, an indication for intestinal transplantation.

RECENT FINDINGS

Biological evaluation of intestinal failure is becoming possible with the use of plasma citrulline as a marker of intestinal mass. Few epidemiological data are available; some indicate an increased incidence of short bowel syndrome-related gastroschisis and persistent high incidence of necrotizing enterocolitis. Morbidity and mortality data in pediatric patients with short bowel syndrome are limited, while long-term outcome is better documented from recently reported cohorts. Non-transplant surgery is one of the best options for patients with unadapted short bowel syndrome. Isolated liver transplantation may be avoided. The use of trophic factors for enhancing mucosal hyperplasia still remains disappointing.

SUMMARY

The management should include therapies adapted to each stage of intestinal failure, based on a multidisciplinary approach in centers involving pediatric surgery, pediatric gastroenterology, parenteral nutrition expertise, home-parenteral nutrition program, and liver-intestinal transplantation experience. If managed appropriately, the prognosis of short bowel syndrome is excellent, with limited indications for intestinal and/or liver transplantation. Timing for patient referral in specialized centers remains an issue.

Causes and management of intestinal failure in children

Intestinal failure is a condition requiring the use of parenteral nutrition as long as it persists. Causes of severe protracted intestinal failure include short bowel syndrome, congenital diseases of enterocyte development, and severe motility disorders (total or subtotal aganglionosis or chronic intestinal pseudo-obstruction syndrome). Intestinal failure may be irreversible in some patients, thus requiring permanent parenteral nutrition. Liver disease may develop with subsequent end-stage liver cirrhosis in patients with intestinal failure as a consequence of both underlying digestive disease and unadapted parenteral nutrition. Death will occur if combined liver-intestine transplantation is not performed. Catheter-related sepsis and/or extensive vascular thrombosis may impede the continuation of a safe and efficient parenteral nutrition and may also require intestinal transplantation in some selected cases. Thus management of patients with intestinal failure requires an early recognition of the condition and the analysis of its risk of irreversibility. Timing of referral for intestinal transplantation remains a crucial issue. As a consequence, management should include therapies adapted to each stage of intestinal failure based on a multidisciplinary approach in centers involving pediatric gastroenterology, parenteral nutrition expertise, home parenteral nutrition program, pediatric surgery, and liver intestinal transplantation program.

Parenteral nutrition-associated liver disease and the role for isolated intestine and intestine/liver transplantation

Parenteral nutrition-associated liver disease (PNALD) is the most devastating complication of long-term parenteral nutrition therapy. Because its progression is typically insidious and its long-term consequences are generally underappreciated, PNALD is often recognized too late, when liver injury is irreversible. When end-stage liver disease (ESLD) develops in these patients, most potential interventions are futile and transplantation of both an intestine and a liver becomes the only viable option, despite the relatively poor outcomes associated with this combined procedure. Although likely multifactorial in origin, the etiology of PNALD is poorly understood. Early clinical intervention with a combination of nutritional, medical, hormonal, and surgical therapies can be effective in preventing liver disease progression. If these interventions fail, intestinal transplantation should be performed expeditiously before development of ESLD mandates simultaneous inclusion of a liver graft as well.

Taurine and cholestasis associated to TPN. Experimental study in rabbit model

Taurine seems to be essential in the newborn for bile acid (BA) tauroconjugation, and its deficiency has been implicated in total parenteral nutrition-associated cholestasis (TPN-AC). Our purpose was to study the relationship between taurine (Ta) and TPN-AC in rabbits, which have a similar biliary metabolism to that of humans. We used 40 young rabbits, fed for 10 days according to the following four groups: GA [10] given TPN, with amino acid solution (AA) but without taurine (Ta) or its AA-precursors (methionine, cysteine, and serine); GB [10] the same but only without taurine; GC [10] the same but with taurine and its precursors; and GD [10] the control group with oral nutrition and saline infusion. Complete blood and bile analytical data were obtained and analyzed, including plasma AA and BA. Liver samples were studied under optical and electron microscopy. Serum: In GC there was a 20% increase in the AA-precursors, but paradoxically it was greater in GA. Bile: In GC there was 30% more excretion of total and free BA compared with less than 20% in GA and GB. Regarding toxic BA, there was a 15% decline in GLC3S excretion, but more than 20% in LCA excretion, than in GA and GB. Moreover, in GC the glyco-/tauro-conjugate ratio was worse than in the other groups. Histomorphology: While in GA and GB liver steatosis was diffuse (microsteatohepatitis type), in GC there was macrosteatosis with mitochondria-surrounded lipid droplets. In GA and GB, the canaliculi appeared dilated, with abundant bile plugs and loss of microvilli. There are signs that taurine may protect against TPN-AC. The mechanism does not seem to be BA tauroconjugation, but probably taurine's antioxidant, membrane stabilization (with Ca2+ and HCO3-), and/or osmotic effects.