Progressive liver, kidney, and heart degeneration in children and adults affected by TULP3 mutations.

Organ fibrosis is a shared endpoint of many diseases, yet underlying mechanisms are not well understood. Several pathways governed by the primary cilium, a sensory antenna present on most vertebrate cells, have been linked with fibrosis. Ciliopathies usually start early in life and represent a considerable disease burden. We performed massively parallel sequencing by using cohorts of genetically unsolved individuals with unexplained liver and kidney failure and correlated this with clinical, imaging, and histopathological analyses. Mechanistic studies were conducted with a vertebrate model and primary cells. We detected bi-allelic deleterious variants in TULP3, encoding a critical adaptor protein for ciliary trafficking, in a total of 15 mostly adult individuals, originating from eight unrelated families, with progressive degenerative liver fibrosis, fibrocystic kidney disease, and hypertrophic cardiomyopathy with atypical fibrotic patterns on histopathology. We recapitulated the human phenotype in adult zebrafish and confirmed disruption of critical ciliary cargo composition in several primary cell lines derived from affected individuals. Further, we show interaction between TULP3 and the nuclear deacetylase SIRT1, with roles in DNA damage repair and fibrosis, and report increased DNA damage ex vivo. Transcriptomic studies demonstrated upregulation of profibrotic pathways with gene clusters for hypertrophic cardiomyopathy and WNT and TGF-ß signaling. These findings identify variants in TULP3 as a monogenic cause for progressive degenerative disease of major organs in which affected individuals benefit from early detection and improved clinical management. Elucidation of mechanisms crucial for DNA damage repair and tissue maintenance will guide novel therapeutic avenues for this and similar genetic and non-genomic diseases.

Development and validation of pFIB scores for exclusion of significant liver fibrosis in pediatric MASLD.

BACKGROUND AND AIMS: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent pediatric liver disease, yet accurate risk scores for referral of children/adolescents with suspected clinically significant liver fibrosis are currently lacking. APPROACH AND RESULTS: Clinical and biochemical variables were collected in a prospective cohort of 327 children and adolescents with severe obesity, in whom liver fibrosis was evaluated by transient elastography. Logistic regression was performed to establish continuous (pFIB-c) and simplified (pFIB-6) diagnostic scores that accurately exclude significant (≥F2) fibrosis. Performance for each was compared to established noninvve fibrosis scores. These scores were validated in elastography (n=504) and multiple biopsy-proven MASLD (n=261) cohorts. Patient sex, ethnicity, weight z-score, homeostatic model assessment of insulin resistance index, ALT, and presence of hypertension were included in the scores. The pFIB-c and pFIB-6 exhibited good discriminatory capacity (c-statistic of 0.839 and 0.826), outperforming existing indices. Negative predictive values were >90% for both scores in the derivation and elastography validation cohorts. Performance in the histological cohorts varied (AUROCs for the pFIB-c between 0.710 and 0.770), as the scores were less accurate when applied to populations in tertiary referral centers characterized by a high prevalence of significant fibrosis and high ALT levels. CONCLUSIONS: Analyzing several cohorts totaling approximately 1100 children and adolescents, we developed novel risk scores incorporating readily available clinical variables. In accordance with the aim of excluding pediatric MASLD-associated fibrosis, the scores performed better in nonselected cohorts of children and adolescents living with obesity than in patients referred to tertiary liver units.

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.

Paediatric porto-sinusoidal vascular disease: Two different clinical phenotypes with subtle histological differences.

BACKGROUND AND AIMS: In paediatrics, porto-sinusoidal vascular disease (PSVD) is relatively unknown and probably underdiagnosed. We aimed to describe clinical phenotypes, histology and outcome of children diagnosed with PSVD. METHODS: Retrospective multicentre study of children diagnosed with PSVD. Diagnosis of PSVD was based on histopathology reports; liver specimens were re-evaluated by two expert liver pathologists. RESULTS: Sixty two children diagnosed with PSVD (M/F = 36/26, median age 6.6 years, range 3.3-10.6), from 7 centres, were included. Thirty-six presented with non-cirrhotic portal hypertension, PH, (PH-PSVD Group = 58%) while 26 had a liver biopsy because of chronic elevation of transaminases without PH (noPH-PSVD Group = 42%). On histology review, the two groups differed for the prevalence of obliterative portal venopathy (more prevalent in PH-PSVD, p = 0.005), and hypervascularised portal tracts (more common in noPH-PSVD, p = 0.039), the other histological changes were equally distributed. At multivariate analysis, platelet count ≤185 000/mm3 was the only independent determinant of PH (p < 0.001). After a median follow-up of 7 years (range 3.0-11.2), in PH-PSVD group 3/36 (8%) required TIPS placement, 5/36 (14%) developed pulmonary vascular complications of PH, and 7/36 (19%) required liver transplantation. In noPH-PSVD none progressed to PH nor had complications. CONCLUSIONS: Paediatric patients with PSVD present with two different clinical phenotypes, one characterised by PH and one by chronic elevation of transaminases without PH. PSVD should be included among the conditions causing isolated hypertransaminasaemia. On histology, the differences between the two groups are subtle. Medium-term outcome is favourable in patients without PH; progression of the disease is observed in those with PH.

The impact of liver transplantation on health-related quality of life in (acute) intoxication-type inborn errors of metabolism.

Organic acidurias (OAs), urea-cycle disorders (UCDs), and maple syrup urine disease (MSUD) belong to the category of intoxication-type inborn errors of metabolism (IT-IEM). Liver transplantation (LTx) is increasingly utilized in IT-IEM. However, its impact has been mainly focused on clinical outcome measures and rarely on health-related quality of life (HRQoL). Aim of the study was to investigate the impact of LTx on HrQoL in IT-IEMs. This single center prospective study involved 32 patients (15 OA, 11 UCD, 6 MSUD; median age at LTx 3.0 years, range 0.8-26.0). HRQoL was assessed pre/post transplantation by PedsQL-General Module 4.0 and by MetabQoL 1.0, a specifically designed tool for IT-IEM. PedsQL highlighted significant post-LTx improvements in total and physical functioning in both patients' and parents' scores. According to age at transplantation (≤3 vs. >3 years), younger patients showed higher post-LTx scores on Physical (p = 0.03), Social (p < 0.001), and Total (p =0.007) functioning. MetabQoL confirmed significant post-LTx changes in Total and Physical functioning in both patients and parents scores (p ≤ 0.009). Differently from PedsQL, MetabQoL Mental (patients p = 0.013, parents p = 0.03) and Social scores (patients p = 0.02, parents p = 0.012) were significantly higher post-LTx. Significant improvements (p = 0.001-0.04) were also detected both in self- and proxy-reports for almost all MetabQoL subscales. This study shows the importance of assessing the impact of transplantation on HrQoL, a meaningful outcome reflecting patients' wellbeing. LTx is associated with significant improvements of HrQol in both self- and parent-reports. The comparison between PedsQL-GM and MetabQoL highlighted that MetabQoL demonstrated higher sensitivity in the assessment of disease-specific domains than the generic PedsQL tool.

Allograft Fibrosis After Pediatric Liver Transplantation: Incidence, Risk Factors, and Evolution.

Allograft fibrosis (AF) after pediatric liver transplantation (pLT) is frequent, but its dynamics are unclear. Our aim was to assess the evolution and risk factors of AF after pLT. A retrospective single-center analysis of pLT patients with a follow-up of ≥5 years who underwent protocol liver biopsies at 6 months, 1 year, 2 years, 5 years, and 10 years was performed. Fibrosis was assessed using the METAVIR and Ishak systems and the liver allograft fibrosis score (LAFs). Of 219 pLTs performed from 2008 to 2018, 80 (36.5%) pLTs were included, and 320 biopsies were reviewed. At 6 months after pLT, fibrosis was found in 54 (67.5%) patients by the METAVIR/Ishak systems and in 59 (73.8%) by the LAFs (P = 0.65). By 5 years, AF was detected in 67 (83.8%), 69 (86.3%), and 72 (90%) specimens using the METAVIR, Ishak, and LAFs systems, respectively (P = 0.54); mild (METAVIR, 51 [63.8%]; Ishak, 60 [75%]; LAFs, 65 [81.2%]) and moderate (METAVIR, 16 [20%]; Ishak, 9 [11.9%]; LAFs, 7 [8.8%]) stages were detected, but severe fibrosis was not found (P = 0.09). In the LAFs, fibrosis involved the portal (85%), sinusoidal (15%), and centrolobular (12%) areas. Of 18 patients with 10-year protocol biopsies, AF was present in 16 (90%), including 1 (5.5%) with severe fibrosis. In all systems, 36.3% of patients showed fibrosis progression from 2 years to 5 years after LT, but they remained stable at the 10-year biopsies without clinical implications. In multivariate analysis, only donor age >40 years was a risk factor for moderate AF at 5 years after LT (odds ratio, 8.3; 95% confidence interval, 1.6-42.1, P = 0.01). Cold ischemia time (CIT) >8 hours was associated with portal (P < 0.001)/sinusoidal fibrosis (P = 0.04), donor age >40 years was associated with sinusoidal (P = 0.01)/centrilobular (P = 0.04) fibrosis, and low tacrolimus trough level within 1 year after LT was associated with centrilobular fibrosis (P = 0.02). AF has a high incidence after pLT, occurring early after transplantation. In most cases, AF is mild or moderate and remains stable in the long run without clinical implications. Donor selection, short CIT, and immunosuppression adherence are crucial to reducing the risk of advanced AF.

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.

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.

Does the Treatment After Kasai Procedure Influence Biliary Atresia Outcome and Native Liver Survival?

OBJECTIVES: Biliary atresia (BA) is a rare and progressive idiopathic disease affecting the biliary tract that can lead to end-stage liver disease. The main treatment is Kasai portoenterostomy (KP). The use of adjuvant therapy (AT; prophylactic antibiotics and steroids) after KP aims to prevent cholangitis and reduce the need for liver transplantation (LT), but there is a lack of evidence on their effectiveness. We investigated the impact of significant changes in the post-KP protocol on the overall outcomes of BA. METHODS: We enrolled 43 consecutive infants undergoing KP at Bambino Gesù Children's Hospital between July 2012 and October 2018. We compared AT (AT group; n=25) against no treatment (AT-free group; n = 18). RESULTS: No significant differences in anthropometric and laboratory parameters were shown between the 2 groups at baseline and every study evaluation (1, 3, and 6 months). The incidences of clinical complications of liver disease were similar. Six months post-KP, the achievement of serum total bilirubin ≤1.5 mg/dL and satisfactory Pediatric End-Stage Liver Disease scores were not significantly different between the 2 groups. Cholangitis was observed in 30% of patients in the first 6 months postoperatively: 33% and 28% in the AT-free and AT groups, respectively (P = 0.18). Survival to LT listing at 12 months and without LT at 24 months were not significantly different between the 2 groups (P > 0.05). CONCLUSIONS: AT after KP confirmed conflicting results; therefore, multicentered, prospective, randomized control studies are needed to better understand its utility after KP, especially in the multidrug resistance spread era.

Establishment of a Seronegative Occult Infection With an Active Hepatitis B Virus Reservoir Enriched of Vaccine Escape Mutations in a Vaccinated Infant After Liver Transplantation.

We describe the establishment of a seronegative occult hepatitis B virus (HBV) infection (OBI) in a successfully vaccinated infant who underwent liver transplantation from an donor positive for antibody to hepatitis B core antigen (anti-HBc). The use of highly sensitive droplet digital polymerase chain reaction assays revealed a not negligible and transcriptionally active intrahepatic HBV reservoir (circular covalently closed DNA, relaxed circular DNA, and pregenomic RNA: 5.6, 2.4, and 1.1 copies/1000 cells, respectively), capable to sustain ongoing viral production and initial liver damage. Next-generation sequencing revealed a peculiar enrichment of hepatitis B surface antigen vaccine-escape mutations that could have played a crucial role in OBI transmission. This clinical case highlights the pathobiological complexity and the diagnostic challenges underlying OBI.

Successful percutaneous transhepatic recanalization of a completely obstructed hepatico-jejunal anastomosis in a child with liver transplantation: Unusual employment of the transseptal puncture system.

Stenosis of the HJ is a common complication of pediatric split LT with high morbidity and possible evolution to secondary biliary cirrhosis and re-transplantation if not treated. Because the endoscopy is generally infeasible in the Roux-en-Y, percutaneous interventional radiology management is usually the safest and most effective approach to avoid surgical revision of a stenotic bilio-enteric anastomosis. We present the case of a child with acute onset of cholestasis 7 months after left lateral segment partial LT due to occlusion of the HJ. The biliary stricture was found to be non-crossable with conventional interventional radiological techniques. The obstruction was resolved creating a new bilio-digestive communication via percutaneous transhepatic approach using the TPS. This device is usually employed by the interventional cardiologist to perform some procedures requiring the direct access to the left atrium through interatrial septal puncture. In conclusion, percutaneous transhepatic recanalization of the hepato-jejuno anastomosis is a rare but feasible and valuable procedure alternative to the surgical resolution even in small infants. Although few cases have been reported in literature, it has to be considered an additional treatment option when the conventional approaches fail.

Liver Transplantation and Gut Microbiota Profiling in a Child Colonized by a Multi-Drug Resistant Klebsiella pneumoniae: A New Approach to Move from Antibiotic to "Eubiotic" Control of Microbial Resistance.

The increase of microorganisms multi-drug resistant (MDR) to antibiotics (ATBs) is becoming a global emergency, especially in frail subjects. In chronic liver disease (LD) with indications for liver transplantation (LT), MDR colonization can significantly affect the LT outcome. However, no clear guidelines for microbial management are available. A novel approach toward MDR-colonized patients undergoing LT was developed at our Center refraining from ATBs use during the transplant waiting list, and use of an intensive perioperative prophylaxis cycle. This study aimed to couple clinical evaluation with monitoring of gut microbiota in a pediatric LD patient colonized with MDR Klebsiella pneumoniae (KP) who underwent LT. No peri-transplant complications were reported, and a decontamination from the MDR bacteria occurred during follow-up. Significant changes in gut microbiota, especially during ATB treatment, were reported by microbiota profiling. Patterns of Klebsiella predominance and microbiota diversity revealed opposite temporal trends, with Klebsiella ecological microbiota niches linked to ATB-driven selection. Our infection control program appeared to control complications following LT in an MDR-KP-colonized patient. The perioperative ATB regimen, acting as LT prophylaxis, triggered MDR-KP overgrowth and gut dysbiosis, but buffered infectious processes. Mechanisms modulating the gut ecosystem should be taken into account in MDR colonization clinical management.

Macrophage recruitment by fibrocystin-defective biliary epithelial cells promotes portal fibrosis in congenital hepatic fibrosis.

UNLABELLED: Congenital hepatic fibrosis (CHF) is a disease of the biliary epithelium characterized by bile duct changes resembling ductal plate malformations and by progressive peribiliary fibrosis, in the absence of overt necroinflammation. Progressive liver fibrosis leads to portal hypertension and liver failure; however, the mechanisms leading to fibrosis in CHF remain elusive. CHF is caused by mutations in PKHD1, a gene encoding for fibrocystin, a ciliary protein expressed in cholangiocytes. Using a fibrocystin-defective (Pkhd1(del4/del4)) mouse, which is orthologous of CHF, we show that Pkhd1(del4/del4) cholangiocytes are characterized by a ß-catenin-dependent secretion of a range of chemokines, including chemokine (C-X-C motif) ligands 1, 10, and 12, which stimulate bone marrow-derived macrophage recruitment. We also show that Pkhd1(del4/del4) cholangiocytes, in turn, respond to proinflammatory cytokines released by macrophages by up-regulating αvß6 integrin, an activator of latent local transforming growth factor-ß1. While the macrophage infiltrate is initially dominated by the M1 phenotype, the profibrogenic M2 phenotype increases with disease progression, along with the number of portal myofibroblasts. Consistent with these findings, clodronate-induced macrophage depletion results in a significant reduction of portal fibrosis and portal hypertension as well as of liver cysts. CONCLUSION: Fibrosis can be initiated by an epithelial cell dysfunction, leading to low-grade inflammation, macrophage recruitment, and collagen deposition; these findings establish a new paradigm for biliary fibrosis and represent a model to understand the relationship between cell dysfunction, parainflammation, liver fibrosis, and macrophage polarization over time.

Autoimmune liver diseases and inflammatory bowel diseases in children: current issues and future perspectives.

Inflammatory bowel diseases (IBDs) represent a group of intestinal disorders with a chronic and relapsing inflammation of the gut, and with a potential risk of systemic involvement of other organs and systems. Over the pediatric age, an incidence higher than 20% of developing extraintestinal manifestation during follow-up has been reported. The liver and the biliary system are frequently involved, and primary sclerosing cholangitis (PSC) is the most predominant entity with an incidence rate of 6.4-7.8% in children. PSC recognizes a multifactorial pathogenesis, and so far a not fully known mechanism for this association. The peculiar phenotype and the distinct clinical course of patients with IBD and PSC-associated make this 'linkage' an attractive study model to better understand mechanisms underlying these diseases. Approaching to these patients is complex and multidisciplinary, and a unique therapeutic strategy has not been standardized yet. New medications are being studied; however, further studies are needed to fully understand the pathogenesis and to improve the care of these patients. The aim of this paper is to review the recent literature regarding hepatobiliary involvement in IBD patients, with particular attention to PSC, and to provide the latest information for a correct diagnosis and appropriate management.

Metabolic-Associated Steatotic Liver Disease (MASLD): A New Term for a More Appropriate Therapy in Pediatrics?

The term "non-alcoholic fatty liver disease" (NAFLD) has been, for a long time, used to describe the spectrum of liver lesions encompassing steatosis, steatohepatitis (NASH), and steatotic cirrhosis [...].