Biliary atresia in preterm infants: a single center experience and review of literature.

Introduction: The diagnosis of biliary atresia (BA) remains challenging, and there is still uncertainty regarding the optimal time to perform a Kasai portoenterostomy (KPE). Little is known about the difficulties in the diagnosis and outcomes of BA in preterm infants (PBA). This study, which represents the first Italian report of preterm infants with BA, aims to describe a single-center experience of BA in preterm newborns. Methods: We retrospectively reviewed all infants consecutively diagnosed with BA who underwent a Kasai procedure at the Bambino Gesù Children's Hospital between January 1998 and December 2021. Prematurity was defined as a gestational age (GA) of <37 weeks. Demographic, laboratory, and histology data were recorded, and the main outcomes considered were clearance of jaundice (COJ), native liver survival, and mortality. Results: A total of 21 PBA were compared with 117 term BA controls (TBA). The median GA of PBA was 35.1 (32-36.1) weeks, with a mean birth weight of 2,100 (1,897-2,800) g. Age at first presentation was significantly lower in PBA patients: 46 (22-68) vs. 61 (44-72) days; p = 0.02. The median age at KPE was similar between the two groups: 70 days (33 corrected) for PBA vs. 67 in TBA; p = 0.8. At the time of surgery, median serum bilirubin was lower in the PBA group (7.7 vs. 8.6 mg/dl, p = 0.04). Similarly, the median APRi at the time of KPE was lower but not significant in the PBA group: 1.09 vs. 1.16; p = 0.8. No differences were found in terms of COJ between the PBA and TBA groups: n = 9 (43%) vs. 34 (35%); p = 0.2. Overall native liver survival was similar between the two groups: 8.6 (4.8-12.2) for the PBA group vs. 7.6 (5.6-9.5) years for the TBA group with no significant differences; p = 0.45. Post-KPE native liver survival was similar between the two groups: 38% vs. 52% at 5 years for the TBA and PBA groups, respectively; p = 0.54. Conclusion: The PBA and TBA groups appear to have similar outcomes in terms of COJ, overall native liver survival, and 5-year liver survival. Considering the corrected GA, early KPE is related to lower cholestatic damage. Further multicenter studies are required.

Histopathological Spectrum and Molecular Characterization of Liver Tumors in the Setting of Fontan-Associated Liver Disease.

PURPOSE: Univentricular heart is corrected with the Fontan procedure (FP). In the long term, so-called Fontan-associated liver diseases (FALDs) can develop. The aim of this study is to analyze the molecular profile of FALDs. METHODS: FALDs between January 1990 and December 2022 were reviewed for histology and immunohistochemistry, laboratory data, and images. Targeted next generation sequencing (NGS), performed on the DNA and RNA of both neoplastic and non-lesional liver tissue, was applied. RESULTS: A total of 31/208 nodules > 1 cm in diameter were identified on imaging, but a liver biopsy was available for five patient demonstrating the following: one hepatocellular adenoma (HA), two hepatocellular carcinomas (HCCs), one fibrolamellar carcinoma (FLC), and one intrahepatic cholangiocarcinoma (ICC). Molecular analysis showed a copy number alteration involving FGFR3 in three cases (two HCCs and one ICC) as well as one HCC with a hotspot mutation on the CTNNB1 and NRAS genes. Tumor mutational burden ranged from low to intermediate. A variant of uncertain significance in GNAS was present in two HCCs and in one ICC. The same molecular profile was observed in a non-lesional liver. A DNAJB1-PRKACA fusion was detected only in one FLC. CONCLUSIONS: Neoplastic FALDs show some unusual molecular profiles compared with non-Fontan ones. The presence of the same alterations in non-lesional cardiac cirrhosis could contribute to the development of FALD.

Application of a pattern-based approach to histological diagnosis in very early onset IBD (VEO-IBD) in a multicentric cohort of children with emphasis on monogenic disease with IBD-like morphology.

AIMS: Very early-onset inflammatory bowel disease (VEO-IBD) is a clinical umbrella term referring to IBD-like symptoms arising in children before the age of 6 years, encompassing both 'pure' IBD, such as ulcerative colitis (UC) and Crohn's disease (CD) and monogenic diseases (MDs), the latter often involving genes associated with primary immunodeficiencies. Moreover, histological features in gastrointestinal (GI) biopsies in MD can also have IBD-like morphology, making differential diagnosis difficult. Correct diagnosis is fundamental, as MDs show a more severe clinical course and their inadequate/untimely recognition leads to inappropriate therapy. METHODS AND RESULTS: Biopsy samples from the lower and upper GI tract of 93 clinically diagnosed VEO-IBD children were retrospectively selected in a multicentre cohort and histologically re-evaluated by 10 pathologists blinded to clinical information. Each case was classified according to morphological patterns, including UC-like; CD-like; enterocolitis-like; apoptotic; eosinophil-rich; and IBD-unclassified (IBD-U). Nine (69%) MD children showed IBD-like morphology; only the IBD-U pattern correlated with MD diagnosis (P = 0.02) (available in 64 cases: 51 non-MD, true early-onset IBD/other; 13 MD cases). MD patients showed earlier GI symptom onset (18.7 versus 26.9 months) and were sent to endoscopy earlier (22 versus 37 months), these differences were statistically significant (P < 0.05). Upper GI histology was informative in 37 biopsies. CONCLUSIONS: The diagnosis of the underlying cause of VEO-IBD requires a multidisciplinary setting, and pathology, while being one of the fundamental puzzle pieces, is often difficult to interpret. A pattern-based histological approach is therefore suggested, thus aiding the pathologist in VEO-IBD reporting and multidisciplinary discussion.

Molecular Profiling of a Hepatocellular Neoplasm Not Otherwise Specified (HCN-NOS) Demonstrates Distinct Molecular Features in Hepatoblastoma and HCC-Like Components.

Hepatoblastomas (HB) are embryonal tumors with quiet genomes diagnosed mostly in children under 3 years of age and often cured by surgical resection and chemotherapy. However, a subset of HBs behave aggressively, displaying characteristic histologic features and higher genomic instability. Hepatocellular neoplasm-not otherwise specified (HCN-NOS) is a provisional diagnostic category for tumors exhibiting either intermediate or a combination of both HB and hepatocellular carcinoma (HCC) histological features. In this study, we characterized an HCN-NOS diagnosed in a 3-year-old patient presenting with a liver mass, in which both HB and HCC histological components were amendable to macro-dissection and molecular profiling. The spectrum of mutations, copy number changes, mRNA, and protein expression profiles within these 2 histologically distinct tumor areas demonstrate molecular heterogeneity and suggest intratumoral clonal evolution of this hepatocellular CTNNB1-mutant lesion.

Case report: Neonatal-onset inflammatory bowel disease due to novel compound heterozygous mutations in DUOX2.

Very Early Onset Inflammatory Bowel Disease (VEO-IBD) is potentially associated with genetic disorders of the intestinal epithelial barrier or inborn errors of immunity (IEI). Dual oxidase 2 (DUOX2), an H2O2-producing NADPH oxidase expressed at apical enterocyte membranes, plays a crucial role in innate defense response. Biallelic DUOX2 mutations have been described only in two patients with VEO-IBD to date. We report the case of a 1-month-old female infant who presented persistent high C-reactive protein (CRP) levels from birth and anemia. Positive occult blood and very high calprotectin in the stool were detected and abdominal ultrasound showed thickened last ileal loop. Full endoscopy evaluation revealed important colon stenosis with multiple pseudo-polyploidy formations that resulted refractory to steroid therapy, requiring a partial colic resection. Histological examination of biopsy samples showed morphological features of IBD. Whole Exome Sequencing (WES) disclosed compound heterozygous variants in the DUOX2 gene: the pathogenic c.2524C>T; p.Arg842Ter and the variant of uncertain significance (VUS) c.3175C>T; p.Arg1059Cys. Molecular and functional studies showed the presence of mutant DUOX2 in the intestinal epithelium of the patient, albeit with at least 50% decreased catalytic activity. In conclusion, we describe the third patient to date with compound heterozygous variants of DUOX2, responsible for monogenic neonatal-IBD. This case expands the knowledge about Mendelian causes of VEO-IBD and DUOX2 deficiency. We suggest that DUOX2 should be part of the diagnostic evaluation of patients with suspected monogenic VEO-IBD.

Case Report: The impact of severe cryptosporidiosis on the gut microbiota of a pediatric patient with CD40L immunodeficiency.

Cryptosporidium parvum is a protozoan parasite and one of the leading causes of gastroenteritis in the world, primarily affecting very young children and immunocompromised patients. While infection is usually self-limiting, it can become chronic and even lethal in these vulnerable populations, in whom Cryptosporidium treatments are generally ineffective, due to their acting in concert with a functioning immune system. Here, we describe a case of chronic cryptosporidiosis in a European child with severe CD40L immunodeficiency infected with Cryptosporidium parvum of the IIa20G1 subgenotype, a lineage which has thus far only ever been described in the Middle East. After years of on-off treatment with conventional and non-conventional anti-parasitic drugs failed to clear parasitosis, we performed targeted metagenomics to observe the bacterial composition of the patient's gut microbiota (GM), and to evaluate fecal microbiota transplantation (FMT) as a potential treatment option. We found that C. parvum infection led to significant shifts in GM bacterial composition in our patient, with consequent shifts in predicted intestinal functional signatures consistent with a state of persistent inflammation. This, combined with the patient's poor prognosis and increasing parasitic burden despite many rounds of anti-parasitic drug treatments, made the patient a potential candidate for an experimental FMT procedure. Unfortunately, given the many comorbidities that were precipitated by the patient's immunodeficiency and chronic C. parvum infection, FMT was postponed in favor of more urgently necessary liver and bone marrow transplants. Tragically, after the first liver transplant failed, the patient lost his life before undergoing FMT and a second liver transplant. With this case report, we present the first description of how cryptosporidiosis can shape the gut microbiota of a pediatric patient with severe immunodeficiency. Finally, we discuss how both our results and the current scientific literature suggest that GM modulations, either by probiotics or FMT, can become novel treatment options for chronic Cryptosporidium infection and its consequent complications, especially in those patients who do not respond to the currently available anti-parasitic therapies.

Identification and experimental validation of druggable epigenetic targets in hepatoblastoma.

BACKGROUND & AIMS: Hepatoblastoma (HB) is the most frequent childhood liver cancer. Patients with aggressive tumors have limited therapeutic options; therefore, a better understanding of HB pathogenesis is needed to improve treatment. HBs have a very low mutational burden; however, epigenetic alterations are increasingly recognized. We aimed to identify epigenetic regulators consistently dysregulated in HB and to evaluate the therapeutic efficacy of their targeting in clinically relevant models. METHODS: We performed a comprehensive transcriptomic analysis of 180 epigenetic genes. Data from fetal, pediatric, adult, peritumoral (n = 72) and tumoral (n = 91) tissues were integrated. Selected epigenetic drugs were tested in HB cells. The most relevant epigenetic target identified was validated in primary HB cells, HB organoids, a patient-derived xenograft model, and a genetic mouse model. Transcriptomic, proteomic and metabolomic mechanistic analyses were performed. RESULTS: Altered expression of genes regulating DNA methylation and histone modifications was consistently observed in association with molecular and clinical features of poor prognosis. The histone methyltransferase G9a was markedly upregulated in tumors with epigenetic and transcriptomic traits of increased malignancy. Pharmacological targeting of G9a significantly inhibited growth of HB cells, organoids and patient-derived xenografts. Development of HB induced by oncogenic forms of ß-catenin and YAP1 was ablated in mice with hepatocyte-specific deletion of G9a. We observed that HBs undergo significant transcriptional rewiring in genes involved in amino acid metabolism and ribosomal biogenesis. G9a inhibition counteracted these pro-tumorigenic adaptations. Mechanistically, G9a targeting potently repressed the expression of c-MYC and ATF4, master regulators of HB metabolic reprogramming. CONCLUSIONS: HBs display a profound dysregulation of the epigenetic machinery. Pharmacological targeting of key epigenetic effectors exposes metabolic vulnerabilities that can be leveraged to improve the treatment of these patients. IMPACT AND IMPLICATIONS: In spite of recent advances in the management of hepatoblastoma (HB), treatment resistance and drug toxicity are still major concerns. This systematic study reveals the remarkable dysregulation in the expression of epigenetic genes in HB tissues. Through pharmacological and genetic experimental approaches, we demonstrate that the histone-lysine-methyltransferase G9a is an excellent drug target in HB, which can also be harnessed to enhance the efficacy of chemotherapy. Furthermore, our study highlights the profound pro-tumorigenic metabolic rewiring of HB cells orchestrated by G9a in coordination with the c-MYC oncogene. From a broader perspective, our findings suggest that anti-G9a therapies may also be effective in other c-MYC-dependent tumors.

Achievement of operational tolerance in a pediatric liver transplant recipient following successful hematopoietic stem cell transplantation from a different donor.

Hematopoietic stem cell transplantation (HSCT)-based approaches are increasingly investigated strategies to induce tolerance in recipients of solid allografts. However, in the majority of cases, these approaches rely on the infusion of hematopoietic stem cells recovered from the same solid organ donor. In this report, we describe the case of a boy who received liver transplantation from a deceased donor, who had successfully underwent allogeneic HSCT from an unrelated donor for hepatitis-associated aplastic anemia. In this patient, it was possible to permanently withdraw post-HSCT immune suppression without causing any sign of liver graft dysfunction. To the best of our knowledge, this is the first case of operational tolerance documented in a patient who received combined liver transplantation and HSCT from different donors.

The Expanding Phenotype of ZTTK Syndrome Due to the Heterozygous Variant of SON Gene Focusing on Liver Involvement: Patient Report and Literature Review.

Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome, an intellectual disability syndrome first described in 2016, is caused by heterozygous loss-of-function variants in SON. Haploinsufficiency in SON may affect multiple genes, including those involved in the development and metabolism of multiple organs. Considering the broad spectrum of SON functions, it is to be expected that pathogenic variants in this gene can cause a wide spectrum of clinical symptoms. We present an additional ZTTK syndrome case due to a de novo heterozygous variant in the SON gene (c.5751_5754delAGTT). The clinical manifestations of our patient were similar to those present in previously reported cases; however, the diagnosis of ZTTK syndrome was delayed for a long time and was carried out during the diagnostic work-up of significant chronic liver disease (CLD). CLD has not yet been reported in any series; therefore, our report provides new information on this rare condition and suggests the expansion of the ZTTK syndrome phenotype, including possible liver involvement. Correspondingly, we recommend screening patients with SON variants specifically for liver involvement from the first years of life. Once the CLD has been diagnosed, an appropriate follow-up is mandatory, especially considering the role of SON as an emerging player in cancer development. Further studies are needed to investigate the role of SON haploinsufficiency as a downregulator of essential genes, thus potentially impairing the normal development and/or functions of multiple organs.

New Onset Cardiac Murmur and Exertional Dyspnea in an Apparently Healthy Child: A Rare Localization of Obstructive Myxoma in the Right Ventricle Outflow Tract without Pulmonary Embolization-A Case Report and Literature Review.

Myxomas are slowly growing benign neoplasms which are rare in children. Up to 80% can be located in the left atrium and generate symptoms such as embolism, cardiac failure, fever and weight loss. Rarely, myxomas can be detected in the right ventricle outflow tract, causing arrhythmias, pulmonary emboli and sudden death. We report the case of a 13-year-old healthy child brought to the Emergency Department (ED) of the Children's Hospital Bambino Gesù, Rome, for recent dyspnea, chest pain on exertion and new onset cardiac murmur. Patient underwent medical examination and echocardiogram with the finding of a rounded and lobulated voluminous mass in the right ventricle outflow tract (RVOT) which caused severe obstruction. The contrast computed tomography (CT) scan confirmed the presence of a heterogeneously enhancing soft-tissue mass occupying the RVOT with no evidence of pulmonary embolization. The mass was surgically excised, and the pathologic examination confirmed our suspicion of myxoma. Our experience suggests that myxoma can have mild clinical symptoms, the presentation may be non-specific, and diagnosis can be a challenge Careful examination and a diagnostic imaging workup, primarily with the transthoracic echocardiogram, are needful to make a rapid differential diagnosis and to better manage surgical treatment and follow-up.

Decellularized esophageal tubular scaffold microperforated by quantum molecular resonance technology and seeded with mesenchymal stromal cells for tissue engineering esophageal regeneration.

Current surgical options for patients requiring esophageal replacement suffer from several limitations and do not assure a satisfactory quality of life. Tissue engineering techniques for the creation of customized "self-developing" esophageal substitutes, which are obtained by seeding autologous cells on artificial or natural scaffolds, allow simplifying surgical procedures and achieving good clinical outcomes. In this context, an appealing approach is based on the exploitation of decellularized tissues as biological matrices to be colonized by the appropriate cell types to regenerate the desired organs. With specific regard to the esophagus, the presence of a thick connective texture in the decellularized scaffold hampers an adequate penetration and spatial distribution of cells. In the present work, the Quantum Molecular Resonance® (QMR) technology was used to create a regular microchannel structure inside the connective tissue of full-thickness decellularized tubular porcine esophagi to facilitate a diffuse and uniform spreading of seeded mesenchymal stromal cells within the scaffold. Esophageal samples were thoroughly characterized before and after decellularization and microperforation in terms of residual DNA content, matrix composition, structure and biomechanical features. The scaffold was seeded with mesenchymal stromal cells under dynamic conditions, to assess the ability to be repopulated before its implantation in a large animal model. At the end of the procedure, they resemble the original esophagus, preserving the characteristic multilayer composition and maintaining biomechanical properties adequate for surgery. After the sacrifice we had histological and immunohistochemical evidence of the full-thickness regeneration of the esophageal wall, resembling the native organ. These results suggest the QMR microperforated decellularized esophageal scaffold as a promising device for esophagus regeneration in patients needing esophageal substitution.

3D bioprinting in airway reconstructive surgery: A pilot study.

OBJECTIVES: Open surgery is a reliable choice for congenital subglottic stenosis, that represents the third most common congenital anomaly of the larynx. One of the procedures performed is anterior laryngotracheal reconstruction (LTR) with anterior rib graft. The objective of this preliminary study was to evaluate the potential of 3D printing technology for the realization of laryngo-tracheal scaffold in Polycaprolactone (PCL) implanted in vivo in ovine animal model. METHODS: A 3D computer model of a laryngeal graft and a tracheal graft was designed and printed with PCL through 3D additive manufacturing technology. The scaffolds were seeded with autologous mesenchymal stem cells and cultured in vitro for up to 14 days. Anterior graft LTR with 3D printed scaffolds was performed on 5 sheep. The animals underwent endoscopic examinations at the first, 3rd, 6th, and 12th weeks after surgery and before sacrifice. The integration of the material was evaluated by the pathologist. RESULTS: Two animals showed a favourable postoperative course and were sacrificed at 6 months postoperatively. In these cases, we observed endoscopically a complete integration of the cellularized PCL scaffold into the peri-implant tissues, and the pathologist found the growth of respiratory epithelium on the scaffold's inner surface. Other two animals showed a difficult post-operative recovery characterized by respiratory distress resulting in early sacrifice on postoperative days 31 and 33. In these animals we found a poor integration of the grafts into the tracheal structure, and a better integration of the laryngeal scaffold. The last animal developed a wound abscess and was sacrificed 80 days after surgery. We observed, in this case, a poor scaffold integration and an acute inflammatory reaction. CONCLUSIONS: From the preliminary data obtained we found that the excessive stiffness of the material, along with the anatomical features of the sheep, is a major limitation of this study. It will be necessary in the future to create a new biocompatible, more flexible and elastic graft, to achieve greater integration into surrounding tissues. Bioconstructed grafts could simplify surgery for the treatment of laryngo-tracheal stenosis, particularly in the treatment of long tracheal stenoses, which have, at the moment, very complex surgical options. LEVEL OF EVIDENCE: NA.

Case report: Unusual and extremely severe lipoprotein X-mediated hypercholesterolemia in extrahepatic pediatric cholestasis.

Background: Lipoprotein X (LpX) - mediated extremely severe hyperlipidemia is a possible feature detectable in children with syndromic paucity of intralobular bile ducts (Alagille syndrome) but rarely in other types of intra- and/or extrahepatic infantile cholestasis. Case presentation: Here we report on a previously well 18-month child admitted for cholestatic jaundice and moderate hepatomegaly. Laboratory tests at entry showed conjugated hyperbilirubinemia, elevated values of serum aminotransferases, gamma-glutamyl transpeptidase (GGT) and bile acids (100 folds upper normal values). Extremely severe and ever-increasing hypercholesterolemia (total cholesterol up to 1,730 mg/dl) prompted an extensive search for causes of high GGT and/or hyperlipidemic cholestasis, including an extensive genetic liver panel (negative) and a liver biopsy showing a picture of obstructive cholangitis, biliary fibrosis, and bile duct proliferation with normal MDR3 protein expression. Results of a lipid study showed elevated values of unesterified cholesterol, phospholipids, and borderline/low apolipoprotein B, and low high-density lipoprotein-cholesterol. Chromatographic analysis of plasma lipoproteins fractions isolated by analytical ultracentrifugation revealed the presence of the anomalous lipoprotein (LpX). Magnetic resonance cholangiopancreatography and percutaneous transhepatic cholangiography showed stenosis of the confluence of the bile ducts with dilation of the intrahepatic biliary tract and failure to visualize the extrahepatic biliary tract. Surgery revealed focal fibroinflammatory stenosis of the left and right bile ducts confluence, treated with resection and bilioenteric anastomosis, followed by the rapid disappearance of LpX, paralleling the normalization of serum lipids, bilirubin, and bile acids, with a progressive reduction of hepatobiliary enzymes. Conclusion: We have described a unique case of focal non-neoplastic extrahepatic biliary stenosis of uncertain etiology, presenting with unusual extremely high levels of LpX-mediated hypercholesterolemia, a condition which is frequently mistaken for LDL on routine clinical tests.

Expanding phenotype of FAM111B-related disease focusing on liver involvement: Literature review, report of a case with end-stage liver disease and proposal for a new acronym.

POIKiloderma, tendon contractures, myopathy, pulmonary fibrosis is a congenital multisystem disorder due to FAM111B dominant variants. We present a literature review focusing on the frequency and the impact of hepatic involvement and a case report of a patient with severe end-stage liver disease. Whole exome sequencing (WES) was conducted on the proband and his parents. A de novo FAM111B: c.1879A > G; (p.Arg627Gly) variant was identified. Hepatic involvement is present in 11 out of the 30 patients described in the literature, with different levels of dysfunction ranging from mild transaminitis to liver fibrosis found in three different cases by liver biopsies. Liver involvement seems to be a significant cause of morbidity. We propose to modify the previous acronym in POIK-TMPL: including POIKiloderma, tendon contractures, myopathy, pulmonary fibrosis/pancreas insufficiency and cancer, liver involvement/lymphedema. Moreover, we suggest screening patients with FAM111B variants for liver involvement from the first month of life and continue with an appropriate follow-up. Further studies are needed to better understand this frequent complication.

Non-Invasive Diagnostic Test for Advanced Fibrosis in Adolescents With Non-Alcoholic Fatty Liver Disease.

Introduction: Non-alcoholic fatty liver disease (NAFLD) is a multifaceted disease that includes a wide spectrum of liver damage. The presence and the degree of fibrosis are considered important factors for the prognosis of NAFLD and in predicting the risk of developing cirrhosis. Our aim was to evaluate the usefulness of four fibrosis scores (aspartate aminotransferase/Platelet Index [APRI], FIB-4, NAFLD Fibrosis Score [NFS], and Hepamet) in predicting different degrees of fibrosis among children with biopsy-proven NAFLD. Methods: About 286 adolescents [mean age 14.3 years ± 2.5; 154 (53.6%) males], referred between January 2014 and December 2019, with biopsy-proven NAFLD were enrolled. Results: About 173 (60.4%) patients presented fibrosis at histological analysis. In particular: 140 (49.3%) patients had F = 1, 31 (10.8%), had F = 2 and 2 (0.66%) had F = 3. APRI (AUROC 0.619, 95% CI 0.556-0.679) and Hepamet (AUROC 0.778, 95% CI 0.722-0.828) scores had significant (p < 0.001) accuracy to distinguish subjects with fibrosis; while NFS and FIB-4 had not. APRI had a positive predictive value (PPV) of 62.77% (95% CI 57.96-67.35) and an negative predictive value (NPV) of 52.01% (95% CI 46.54-57.43); Hepamet a PPV of 63.24% (95% CI 59.95-66.41) and an NPV of 61.29% (52.9-69.01). Conclusions: Our study showed that Hepamet and APRI perform better than NFS and FIB-4 for identifying fibrosis in patients with NAFLD, but do not have PPVs so high to be considered diagnostic. Therefore, they cannot be employed, in children, for a certain diagnosis of fibrosis or its progression and cannot replace liver biopsy as the gold diagnostic standard. It is, therefore, necessary to continue to research and develop new markers of exclusive fibrosis.

Liver transplantation in an infant with cerebrotendinous xanthomatosis, cholestasis, and rapid evolution of liver failure.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is a disorder of bile acid (BA) metabolism due to biallelic mutations in CYP27A1. The deposition of cholesterol and cholestanol in multiple tissues results, manifesting as neurologic disease in adults or older children. Neonatal cholestasis (NC) as a presentation of CTX is rare; it may self-resolve or persist, evolving to require liver transplantation (LT). METHODS: We present in the context of similar reports an instance of CTX manifest as NC and requiring LT. RESULTS: A girl aged 4mo was evaluated for NC with normal serum gamma-glutamyl transpeptidase activity. An extensive diagnostic work-up, including liver biopsy, identified no etiology. Rapid progression to end-stage liver disease required LT aged 5mo. The explanted liver showed hepatocyte loss and micronodular cirrhosis. Bile salt export pump (BSEP), encoded by ABCB11, was not demonstrable immunohistochemically. Both severe ABCB11 disease and NR1H4 disease-NR1H4 encodes farsenoid-X receptor, necessary for ABCB11 transcription-were considered. However, selected liver disorder panel sequencing and mass-spectrometry urinary BA profiling identified CTX, with homozygosity for the predictedly pathogenic CYP27A1 variant c.646G > C p.(Ala216Pro). Variation in other genes associated with intrahepatic cholestasis was not detected. Immunohistochemical study of the liver-biopsy specimen found marked deficiency of CYP27A1 expression; BSEP expression was unremarkable. Aged 2y, the girl is free from neurologic disease. CONCLUSIONS: Bile acid synthesis disorders should be routinely included in the NC/"neonatal hepatitis" work-up. The mutually supportive triple approach of BA profiling, immunohistochemical study, and genetic analysis may optimally address diagnosis in CTX, a treatable disease with widely varying presentation.

MYO5B Gene Mutations: A Not Negligible Cause of Intrahepatic Cholestasis of Infancy With Normal Gamma-Glutamyl Transferase Phenotype.

OBJECTIVES: Progressive familial intrahepatic cholestasis is an expanding group of autosomal recessive intrahepatic cholestatic disorders. Recently, next-generation sequencing allowed identifying new genes responsible for new specific disorders. Two biochemical phenotypes have been identified according to gamma-glutamyltransferase (GGT) activity. Mutations of the myosin 5B gene (MYO5B) are known to cause microvillus inclusion disease. Recently, different mutations in MYO5B gene have been reported in patients with low-GGT cholestasis. METHODS: A multicenter retrospective and prospective study was conducted in 32 children with cryptogenic intrahepatic cholestasis. Clinical, biochemical, histological, and treatment data were analyzed in these patients. DNA from peripheral blood was extracted, and all patients were studied by whole exome sequencing followed by Sanger sequencing. RESULTS: Six patients out of 32 had mutations in the MYO5B gene. Of these six patients, the median age at disease onset was 0.8 years, and the median length of follow-up was 4.2 years. The most common signs were pruritus, poor growth, hepatomegaly, jaundice, and hypocholic stools. Two patients also showed intestinal involvement. Transaminases and conjugated bilirubin were moderately increased, serum bile acids elevated, and GGT persistently normal. At anti-Myo5B immunostaining, performed in liver biopsy of two patients, coarse granules were evident within the cytoplasm of hepatocytes while bile salt export pump was normally expressed at the canalicular membrane. Six variants in homozygosity or compound heterozygosity in the MYO5B gene were identified, and three of them have never been described before. All nucleotide alterations were located on the myosin motor domain except one missense variant found in the isoleucine-glutamine calmodulin-binding motif. CONCLUSIONS: We identified causative mutations in MYO5B in 18.7% of a selected cohort of patients with intrahepatic cholestasis confirming a relevant role for the MYO5B gene in low-GGT cholestasis.

Changes in Total Homocysteine and Glutathione Levels After Laparoscopic Sleeve Gastrectomy in Children with Metabolic-Associated Fatty Liver Disease.

PURPOSE: Paediatric obesity is a well-known risk factor for metabolic-associated fatty liver disease (MAFLD). The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy (LSG) on the levels of total homocysteine (tHcy) and total glutathione (tGSH) plasma levels in children with MAFLD. MATERIAL AND METHODS: Twenty-four children with severe obesity who underwent LSG were included in the study. The metabolic parameters, systemic inflammatory markers, one-carbon metabolism products, ultrasound and histological improvement were evaluated at baseline (T0M) and after 12 months from LSG (T12M). RESULTS: The patients exhibited a significant amelioration of several metabolic parameters at T12M. A significant reduction of steatosis was observed at ultrasound (from 72.7% of moderate-severe grade to 0% severe steatosis), accompanied by a statistically significant improvement of ballooning, portal and lobular inflammation and fibrosis. A statistically significant decrease of tumour necrosis factor circulating levels was also observed (T0M median = 290.3, IQR = 281.0-317.0 pg/mL; T12M median = 260.4, IQR = 240.0-279.0 pg/mL; p < 0.0001). After 12 months from LSG, a significant increase of mean plasma levels of tHcy(T0M mean = 15.7 ± 4.1 µmol/L; T12M mean = 21.1 ± 9.3 µmol/L; p = 0.0146) was also observed. The increase of tHcy showed no causal link with the improvement of MAFLD-related inflammatory, metabolic and histological pattern. CONCLUSION: LSG in children with obesity induces an improvement of MAFLD-related metabolic derangement and liver damage, but also a mild hyperhomocysteinemia that should be avoided to prevent cardiovascular risk.

Pattern-based Histologic Approach in Very Early Onset IBD: Main Features and Differential Diagnosis.

Very early onset inflammatory bowel disease (VEO-IBD) is a clinical umbrella classification composed of IBD-like diseases encompassing both classic IBD (Crohn's disease and ulcerative colitis) and monogenic disorder, both arising before 6 years of age. VEO-IBD patients present significant clinical differences from IBD occurring in older children and in adults, including more severe disease, often unresponsive to conventional IBD therapy and a greater proportion of cases featuring an underlying genetic alteration. Histologic findings of gastrointestinal biopsies can show an IBD-like pattern (both Crohn's disease-like and ulcerative colitis-like pattern), an apoptotic-like and enterocolitis-like pattern. Findings of specific morphologic alterations, such as villous blunting, apoptosis, dense eosinophilic infiltrates, lack of plasma cells and severe glandular atrophy, can suggest a monogenic disorder. Moreover, individuals with monogenic disorders may develop significant problems such as primary immunodeficiency, impacting treatment options. Finally, IBD histology in childhood can differ from that in older patients and adults. This complexity makes a differential diagnosis between IBD and other pediatric diseases involving the gastrointestinal tract difficult, especially considering that histologic features can be similar between different diseases. Without an appropriate diagnosis, the clinical course of VEO-IBD has greater potential for escalated treatment regimens involving extensive surgery and more intensive medical therapies rather than specific therapy directed toward the underlying defect. For these reasons, a pattern-based histologic approach correlated with clinical and laboratory findings with a multidisciplinary approach is fundamental to reach a correct diagnosis in an adequate clinical context.