Histological features of liver disease development in the Atp7b-/- mouse: a model of Wilson's disease.

AIMS: Wilson's disease (WD) is caused by mutations in the ATP7B gene, resulting in copper accumulation and toxicity in liver and brain tissues. Due to the initial asymptomatic liver involvement, the progression of liver injuries in WD stays primarily unknown. Atp7b-/- knockout mice have been shown to be an appropriate model of WD for liver involvement. METHODS: A total of 138 Atp7b-/- mice were included and separated into five groups according to age as follows: 6, 20, 39 and 50 weeks without treatment, and 50 weeks with copper chelator treatment from 39 to 50 weeks of age and compared with 101 wild-type (WT) mice at the same stages. The evolution of histological liver lesions was analysed and compared between groups. RESULTS: Significant changes were observed in Atp7b-/- mice compared with WT. Copper deposits in hepatocytes appeared as early as 6 weeks but no significant increase over time was observed. Inflammation appeared as early as 6 weeks and progressed henceforth. Lobular and periportal acidophilic bodies appeared after 20 weeks. Significant atypia was also observed at 20 weeks and increased over time to reach a severe stage at 39 weeks. Fibrosis also became apparent at 20 weeks, progressing subsequently to precirrhotic stages at 50 weeks. Copper content, inflammation and fibrosis scores were significantly reduced in the treated group. No bile duct lesions or dysplastic changes were noted. CONCLUSIONS: Copper accumulation leads to progressive changes in Atp7b-/- mice regarding inflammation, fibrosis and atypia. The severity of liver damage is lessened by chelation therapy.

Evaluation of vitamin B6 supplementation in Wilson's disease patients treated with D-penicillamine.

INTRODUCTION: Wilson's disease (WD) is a copper metabolism disorder characterised by a progressive accumulation of this metal mainly in the liver and the brain. Treatment is based on the removal of copper operated by the chelators, among which, D-penicillamine (DP) is prescribed as a first-line treatment in most situations. There is some evidence in linking the use of DP with a risk of vitamin B6; therefore, vitamin supplementation is sometimes recommended, although non-consensually. The objective of our study was to evaluate the level of vitamin B6 in WD patients treated with DP with and without associated supplementation. METHODOLOGY: All WD patients followed at the National Reference Centre for WD in Lyon between January 2019 and December 2020 treated with DP for more than 1 year were included and separated in two groups according to vitamin B6 supplementation. The level of vitamin B6 was measured by the determination of pyridoxal phosphate (PLP). RESULTS: A total of 37 patients were included. Average age of 23.3±14.8 years, 15 patients with <18 years. Median duration of treatment was 51 (55.8) months. 15 patients were under vitamin B6 supplementation and 22 had interrupted it for more than 1 year. The median PLP level was significantly higher in the group with supplementation, 137.2 (86.7) nmol/L vs 64.9 (30.8) nmol/(p<0.01). No patient had a PLP level<35 nmol/L. CONCLUSION: Long-term stable WD patients under DP treatment probably do not need vitamin B6 supplementation.

Long-Term Urinary Copper Excretion and Exchangeable Copper in Children With Wilson Disease Under Chelation Therapy.

OBJECTIVES: Determining 24-hour urinary copper excretion (UCE) levels is useful for diagnosing Wilson's disease (WD) and for treatment monitoring. Exchangeable copper (ExC) is a novel potential marker, but its long-term changes have never been described in patients under chelation therapy. Our aim was to describe the long-term changes in ExC levels compared to UCE levels in symptomatic WD pediatric patients under chelation therapy. METHODS: A retrospective, descriptive, and analytical study including all patients under 18 years of age, diagnosed between 2006 and 2020, and treated with chelation therapy was conducted at the National Reference Center for WD in Lyon. Ceruloplasmin levels, serum copper, 24 h-UCE, ExC, and liver enzymes at diagnosis and during follow-up were analyzed. RESULTS: Our study included 36 patients, predominantly with hepatic form of WD (n = 31). The median [interquartile range (IQR)] age at diagnosis was 10.5 (8.4-13.1) years, and the median (IQR) follow-up duration was 6.3 (3.3-8.8) years. At diagnosis, the median (IQR) ExC value was 1.01 (0.60-1.52) µmol/L. There was a significant decrease during the first year of chelation treatment ( P = 0.0008), then a stabilization. The median (IQR) ExC values was 0.38 (0.22-0.63) µmol/L at 12-18 months and 0.43 (0.31-0.54) µmol/L at 5 years of chelation treatment ( P = 0.4057). Similarly, there was a significant decrease in 24-hour UCE ( P < 0.001) during the first year of chelation treatment, then a stabilization. CONCLUSIONS: Our study showed a significant decrease in ExC and 24-hour UCE levels during the first year of follow-up; The dynamics of both biomarkers were similar along the follow-up, demonstrating their usefulness in clinical practice for monitoring WD.

Lipids Responsible for Intestinal or Hepatic Disorder: When to Suspect a Familial Intestinal Hypocholesterolemia?

ABSTRACT: Familial intestinal hypocholesterolemias, such as abetalipoproteinemia, hypobetalipoproteinemia, and chylomicron retention disease, are rare genetic diseases that result in a defect in the synthesis or secretion of lipoproteins containing apolipoprotein B.In children, these conditions present with diarrhoea and growth failure, whereas adults present with neuromuscular, ophthalmological, and hepatic symptoms. Simple laboratory investigations have shown that diagnosis can be made from findings of dramatically decreased cholesterol levels, deficiencies in fat-soluble vitamins (mostly vitamin E), endoscopic findings of the characteristic white intestinal mucosa, and fat-loaded enterocytes in biopsy samples. Genetic analysis is used to confirm the diagnosis. Treatment is based on a low-fat diet with essential fatty acid supplementation, high doses of fat-soluble vitamins, and regular and life-long follow-up.The present study examines cases and literature findings of these conditions, and emphasises the need to explore severe hypocholesterolemia and deficiencies in fat-soluble vitamins to not miss these rare, but easy to diagnose and treat, disorders.

Normal serum ApoB48 and red cells vitamin E concentrations after supplementation in a novel compound heterozygous case of abetalipoproteinemia.

BACKGROUND AND AIMS: Abetalipoproteinemia (ABL) is a rare recessive monogenic disease due to MTTP (microsomal triglyceride transfer protein) mutations leading to the absence of plasma apoB-containing lipoproteins. Here we characterize a new ABL case with usual clinical phenotype, hypocholesterolemia, hypotriglyceridemia but normal serum apolipoprotein B48 (apoB48) and red blood cell vitamin E concentrations. METHODS: Histology and MTP activity measurements were performed on intestinal biopsies. Mutations in MTTP were identified by Sanger sequencing, quantitative digital droplet and long-range PCR. Functional consequences of the variants were studied in vitro using a minigene splicing assay, measurement of MTP activity and apoB48 secretion. RESULTS: Intestinal steatosis and the absence of measurable lipid transfer activity in intestinal protein extract supported the diagnosis of ABL. A novel MTTP c.1868G>T variant inherited from the patient's father was identified. This variant gives rise to three mRNA transcripts: one normally spliced, found at a low frequency in intestinal biopsy, carrying the p.(Arg623Leu) missense variant, producing in vitro 65% of normal MTP activity and apoB48 secretion, and two abnormally spliced transcripts resulting in a non-functional MTP protein. Digital droplet PCR and long-range sequencing revealed a previously described c.1067+1217_1141del allele inherited from the mother, removing exon 10. Thus, the patient is compound heterozygous for two dysfunctional MTTP alleles. The p.(Arg623Leu) variant may maintain residual secretion of apoB48. CONCLUSIONS: Complex cases of primary dyslipidemia require the use of a cascade of different methodologies to establish the diagnosis in patients with non-classical biological phenotypes and provide better knowledge on the regulation of lipid metabolism.

Efficacy of two vitamin E formulations in patients with abetalipoproteinemia and chylomicron retention disease.

Abetalipoproteinemia (ABL) and chylomicron retention disease (CMRD) are extremely rare recessive forms of hypobetalipoproteinemia characterized by intestinal lipid malabsorption and severe vitamin E deficiency. Vitamin E is often supplemented in the form of fat-soluble vitamin E acetate, but fat malabsorption considerably limits correction of the deficiency. In this crossover study, we administered two different forms of vitamin E, tocofersolan (a water-soluble derivative of RRR-α-tocopherol) and α-tocopherol acetate, to three patients with ABL and four patients with CMRD. The aims of this study were to evaluate the intestinal absorption characteristics of tocofersolan versus α-tocopherol acetate by measuring the plasma concentrations of α-tocopherol over time after a single oral load and to compare efficacy by evaluating the ability of each formulation to restore vitamin E storage after 4 months of treatment. In patients with ABL, tocofersolan and α-tocopherol acetate bioavailabilities were extremely low (2.8% and 3.1%, respectively). In contrast, bioavailabilities were higher in patients with CMRD (tocofersolan, 24.7%; α-tocopherol acetate, 11.4%). Plasma concentrations of α-tocopherol at 4 months were not significantly different by formulation type in ABL or CMRD. This study provides new insights about vitamin E status in ABL and CMRD and suggests the potential of different formulations as treatment options.

Safety of a New Amino Acid Formula in Infants Allergic to Cow's Milk and Intolerant to Hydrolysates.

OBJECTIVES: Amino acid-based formulas (AAFs) are recommended for children with cow's-milk allergy (CMA) failing to respond to extensively hydrolysed formulas (eHFs). We evaluated the effects of a new thickened AAF (TAAF, Novalac), containing a pectin-based thickener, and a reference AAF (RAAF, Neocate) on allergy symptoms and safety, through blood biochemistry analysis and growth. METHODS: Infants (ages < 18 months) with CMA symptoms failing to respond to eHFs were randomised in a double-blind manner to receive TAAF or RAAF for 3 months. All of the infants were then fed TAAF for 3 additional months. Paediatric visits occurred at 1, 3, and 6 months. Blood samples were collected at inclusion and 3 months. RESULTS: Results at 1 month were previously described. The 75 infants with proven CMA and eHF intolerance tolerated their allocated formula. At 3 months, the dominant allergic symptom had disappeared in 76.2% of the infants with TAAF and in 51.5% of the infants with RAAF (P = 0.026). The Scoring Atopic Dermatitis Index significantly improved more with TAAF than with RAAF (-27.3 ±â€Š2.3 vs -20.8 ±â€Š2.2, P = 0.048). Of the infants, 92.9% had normal stools (soft or formed consistency) with TAAF vs 75.8% with RAAF (P = 0.051). More infants in TAAF group had better quality of nighttime sleep (P = 0.036) and low frequency of irritability signs (P < 0.001). With both formulas, all of the biochemical parameters were within normal ranges. There were no differences between the 2 groups in any of the anthropometric z scores. CONCLUSIONS: The new TAAF was tolerated by all of the infants with CMA and intolerance to eHFs. Anthropometric and clinical data showed that both formulas were safe.

Usefulness of thiopurine metabolites in predicting azathioprine resistance in pediatric IBD patients.

Few data on azathioprine (AZA) therapy for inflammatory bowel disease (IBD) exist for children. We evaluated whether the 6-thioguanine nucleotides (6-TGN) level predicts AZA refractoriness in children with IBD and whether children benefit an AZA dose escalation. Seventy-eight children with IBD initially treated with an AZA dose of 1.5-2.5 mg/kg/day were retrospectively included. The dose was adjusted based on the clinical status. The receiver operating characteristic curve and logistic regression were used to determine predictors for AZA resistance. Initially, 18 of 40 (45%) patients receiving a dose of <2 mg/kg/day and 11 of 38 (28.9%) patients receiving a dose of 2-2.5 mg/kg/day achieved remission. The 6-TGN level above 250 pmol/8.10(8) RBCs was associated with a higher remission rate, though non-significant. Among 35 patients with a dose escalation due to treatment failure, 12 (34.3%) achieved remission (the median 6-TGN level increased from 260 to 394 pmol/8.10(8) RBCs [P = .002]), 23 (67.6%) were AZA refractory. A 6-TGN level above 405 pmol/8.10(8) RBCs was the only predictor for AZA resistance (sensitivity 78.3%, specificity 75%, OR 10.8 [95% CI: 2.1-55.7, P = .004]). Serial metabolite monitoring is useful to identify children with IBD resistant to AZA. Children who cannot achieve remission despite a 6-TGN level above 405 pmol/8.10(8) RBCs should receive alternative therapies than dose increase.

Guidelines for the diagnosis and management of chylomicron retention disease based on a review of the literature and the experience of two centers.

Familial hypocholesterolemia, namely abetalipoproteinemia, hypobetalipoproteinemia and chylomicron retention disease (CRD), are rare genetic diseases that cause malnutrition, failure to thrive, growth failure and vitamin E deficiency, as well as other complications. Recently, the gene implicated in CRD was identified. The diagnosis is often delayed because symptoms are nonspecific. Treatment and follow-up remain poorly defined.The aim of this paper is to provide guidelines for the diagnosis, treatment and follow-up of children with CRD based on a literature overview and two pediatric centers 'experience.The diagnosis is based on a history of chronic diarrhea with fat malabsorption and abnormal lipid profile. Upper endoscopy and histology reveal fat-laden enterocytes whereas vitamin E deficiency is invariably present. Creatine kinase (CK) is usually elevated and hepatic steatosis is common. Genotyping identifies the Sar1b gene mutation.Treatment should be aimed at preventing potential complications. Vomiting, diarrhea and abdominal distension improve on a low-long chain fat diet. Failure to thrive is one of the most common initial clinical findings. Neurological and ophthalmologic complications in CRD are less severe than in other types of familial hypocholesterolemia. However, the vitamin E deficiency status plays a pivotal role in preventing neurological complications. Essential fatty acid (EFA) deficiency is especially severe early in life. Recently, increased CK levels and cardiomyopathy have been described in addition to muscular manifestations. Poor mineralization and delayed bone maturation do occur. A moderate degree of macrovesicular steatosis is common, but no cases of steatohepatitis cirrhosis. Besides a low-long chain fat diet made up uniquely of polyunsaturated fatty acids, treatment includes fat-soluble vitamin supplements and large amounts of vitamin E. Despite fat malabsorption and the absence of postprandial chylomicrons, the oral route can prevent neurological complications even though serum levels of vitamin E remain chronically low. Dietary counseling is needed not only to monitor fat intake and improve symptoms, but also to maintain sufficient caloric and EFA intake. Despite a better understanding of the pathogenesis of CRD, the diagnosis and management of the disease remain a challenge for clinicians. The clinical guidelines proposed will helpfully lead to an earlier diagnosis and the prevention of complications.

Endoscopic treatment of gastroesophageal varices in young infants with cyanoacrylate glue: a pilot study.

BACKGROUND: In children, endoscopic sclerotherapy and variceal ligation (EVL) are the most used techniques for the treatment of gastroesophageal variceal bleeding (VB). However, these techniques achieve poor results in cases of gastric variceal bleeding, and EVL is not applicable in young infants. OBJECTIVE: Our purpose was to evaluate the feasibility, efficacy, and safety of cyanoacrylate glue injection for the treatment of gastroesophageal varices in young infants. DESIGN: Single-center prospective study. PATIENTS: From 2001 to 2005, 8 young infants (