Search Results (67)

Pediatric acute liver failure (PALF) is a rare but life-threatening condition characterized by rapid clinical deterioration and high mortality. Viral infections represent a major etiology of PALF, although the causative agent remains unidentified in a substantial proportion of cases. Human Enteroviruses (EVs) are typically associated with self-limiting illnesses; however, they may rarely cause severe systemic disease, including fulminant hepatitis, particularly in neonates and young children. We describe the case of a 4-year-old previously healthy male who presented with acute fulminant hepatitis secondary to systemic Echovirus 25 (E25) infection, with concomitant Epstein–Barr virus (EBV) co-infection of recent onset. The diagnosis was established through multiplex PCR on cerebrospinal fluid, blood, stool, and nasopharyngeal aspirate, with serotype confirmation by the Italian National Institute of Health. The patient required intensive supportive care including therapeutic plasma exchange (TPE), continuous kidney replacement therapy (CKRT), and intravenous immunoglobulins (IGIV). Despite initial clinical deterioration and placement on the liver transplant list, the patient achieved complete hepatic recovery and was discharged after fourteen days of hospitalization without requiring transplantation. This case highlights the importance of prompt virological workup including enterovirus PCR in children presenting with acute liver failure of undetermined etiology and supports the use of extracorporeal therapies as a bridge to recovery. Full article

Herpes simplex virus 1 (HSV-1) is a rare cause of acute hepatitis, especially in patients with chronic immunosuppression. We performed whole-genome HSV-1 sequencing with a metagenomics approach on peripheral blood samples from an Italian case of fatal acute liver failure with high circulating HSV-1 (1,129,900,000 copies/mL), followed by phylogenetic analysis. After multiple sequence alignment, a final dataset of 182 whole-genome sequences was selected. The sequenced HSV-1 strain belonged to a phylogenetic clade isolated in Florida in 2002 (OQ724868.1). A characterization of single nucleotide polymorphisms and indels was performed to determine their effects on the viral genome: only one variant, classified as an indel, was detected with a high impact effect (c.905_906insGTTTT) in the UL49A gene, which is known to encode a membrane protein regulating virion morphogenesis, replication and assembly. In addition, this study also detected variants in other genes involved in crucial steps of the HSV-1 life cycle, like alpha-regulation (US7), capsid transport (UL36) and viral polymerase function (UL30). In conclusion, the results of this variant analysis confirmed that in HSV-1 hepatitis, some viral regions may be hotspots for adaptive mutations with a substantial impact on viral replication or immune evasion. Full article

Liver involvement in pediatric rheumatologic diseases is an increasingly recognized but often underappreciated clinical issue. Systemic autoimmune and autoinflammatory disorders including juvenile idiopathic arthritis, systemic lupus erythematosus, juvenile dermatomyositis, systemic vasculitis, and mixed connective tissue disease can all affect hepatic structure and function. The mechanisms of injury are multifactorial, encompassing immune-mediated inflammation, macrophage activation, drug-induced toxicity, and metabolic alterations. Hepatic manifestations range from asymptomatic transaminase elevations to fulminant liver failure, frequently influenced by immunosuppressive therapy and comorbid infections. Early recognition through routine biochemical monitoring, imaging, and targeted autoantibody testing is essential for differentiating primary disease activity from treatment-related injury. Timely, multidisciplinary management involving pediatric rheumatology and hepatology teams can prevent progression to chronic liver disease and optimize outcomes. This review summarizes the current understanding of hepatic pathology in pediatric rheumatology, highlighting diagnostic algorithms, monitoring strategies, and emerging therapeutic considerations. Full article

Background Expanded dengue syndrome represents a severe and atypical spectrum of dengue virus infection characterized by multisystem involvement beyond classic manifestations. While mild gastrointestinal symptoms are common in classic dengue, expanded dengue syndrome may present with clinically significant digestive organ involvement, including hepatitis, fulminant hepatic failure, pancreatitis, and acute acalculous cholecystitis. These manifestations often resemble primary gastrointestinal diseases, leading to diagnostic delays and inappropriate management. Despite increasing recognition, the true frequency of digestive system involvement remains poorly defined due to heterogeneous reporting and limited quantitative evidence. Methodology/Principal Findings A systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD420251270772). MEDLINE, Scopus, Web of Science, Embase, CENTRAL, Scielo, and BIREME were searched from inception to December 10, 2025. Primary studies reporting laboratory-confirmed dengue infection with atypical digestive system involvement and sufficient quantitative data were included. Seven studies comprising 1774 participants met eligibility criteria. Random-effects meta-analyses were performed to estimate pooled frequencies of gastrointestinal manifestations. The pooled frequency of hepatic involvement was 7% (95% confidence interval: 0–21), including fulminant hepatic failure (3%) and hepatitis (33%), with substantial heterogeneity. Acute pancreatitis occurred in 3% (95% confidence interval: 0–11) of cases. Acute acalculous cholecystitis was the most frequent manifestation, with a pooled frequency of 21% (95% confidence interval: 3–48). All included studies were classified as low risk of bias. Full article

Hepatitis D virus (HDV) is a very peculiar virus that shares many characteristics with plant viroids. One of its unique characteristics is the requirement for the presence of a helper virus for its replication, and in particular enveloping its virion, a role often played by the hepatitis B virus (HBV). Infection with HDV is frequently associated with more severe disease, which may present with fulminant hepatitis or a more rapid progression to cirrhosis and hepatocellular carcinoma (HCC), when compared to HBV mono-infection. HDV exhibits many peculiarities and enigmas, which have led to it being considered a neglected virus. This review aims to identify the most important gaps in knowledge and peculiarities in the study of this enigmatic virus, from virology to clinical implications. Full article

Congenital toxoplasmosis presents with a wide clinical spectrum, ranging from asymptomatic infection to severe disease with multi-organ failure. We report a rare fatal case of disseminated congenital toxoplasmosis in a human neonate. The infant initially had thrombocytopenia and mild hepatitis, which rapidly progressed to fulminant liver failure. Despite initiation of standard therapy with pyrimethamine, sulfadiazine, and folinic acid on postnatal day 25, the infant died two days later. Autopsy revealed widespread involvement of the liver, spleen, brain, heart, lungs, urinary bladder, and skeletal muscle. To further characterize the infection, genomic sequencing of the isolate (TgHsUS2) was performed, which placed it within clade C (Haplogroup 9) and closely related to reference strains P89 and TgCatBr3. Variant analysis showed type III-like alleles in ROP18, ROP16, and GRA15. These alleles are known to modulate host immunity and may have influenced disease severity in this case. This report highlights the need for rapid recognition and targeted therapy as well as how strain genomics can inform disease mechanisms. Prevention through prenatal screening and maternal treatment during pregnancy may reduce infant mortality. Full article

The Amazon Basin was historically hyperendemic for HBV and HDV, associated with severe outcomes like fulminant hepatitis. Brazil initiated its hepatitis B vaccination in 1989. This study assessed the current prevalence in this endemic region to evaluate the impact of vaccination. A cross-sectional population-based survey enrolled 1100 urban and rural residents. HBsAg prevalence was 1.5%, with no cases in individuals under 20 years, demonstrating interrupted vertical and horizontal transmission. Anti-HBc positivity (30.9%) indicated past exposure, predominantly in those over 30 years. Isolated anti-HBc (10.3%) included two occult HBV infections. HDV coinfection occurred in 25% of HBsAg-positive cases, with HDV RNA detected in two. Anti-HDV positivity was exclusive to adults over 30. Vaccination coverage was poorly documented, but 23.7% had protective anti-HBs titers. HBV vaccination has reduced HBsAg prevalence from high to low endemicity in the region, eliminating chronic infections in younger generations. Persistent HDV in older age groups underscores the need for targeted screening. Despite vaccination record gaps, the findings highlight the program’s success in interrupting transmission and support continued efforts toward HBV/HDV elimination. Full article

Background and Clinical Significance: Progressive familial intrahepatic cholestasis (PFIC) refers to a heterogeneous group of autosomal recessive disorders consisting of mutations of hepatocyte transporting-system genes involved in bile formation. The exact prevalence remains unknown but is estimated at 1 in 500.000 for PFIC 3, caused by mutations in the ABCB4 gene. We report three cases of PFIC 3 from the patient’s sister, brother, and cousin, diagnosed in our Pediatric Department in 2022–2023. Case Presentation: Case 1: A 10-year-old girl was admitted for jaundice and abdominal pain. She was diagnosed with severely advanced hepatic cirrhosis and massive cholestasis. Genetic testing showed ABCB4 homozygous mutation. She rapidly developed fulminant liver failure, and a living donor liver transplant was performed. Case 2: A 6-year-old brother was previously diagnosed with cholestatic hepatitis of unknown cause back in 2018 and presented with similar features (generalized jaundice, severe pruritus with generalized scratching lesions); symptoms had progressively developed from the first year of life. He also exhibited particular facial features (big forehead, twisted ear lobe, straight nose). He received cadaveric liver transplantation. Case 3: Nephew of first two children, a 3-year-5-month-old boy, was admitted for failure to thrive and a one-year history of jaundice, pruritus, and splenomegaly. He was tested positive for homozygous ABCB4 mutation. He is currently under medical treatment with stable liver function. Conclusions: The clinical significance of this particular homozygous variant identified in ABCB4 in our series of cases (c.2534G>T (p.Gly845Val)) was uncertain up to this case report. The present data provide convincing evidence as to the correlation between this mutation and the clinical phenotype of PFIC 3. Full article

Overdose of acetaminophen (APAP) produces fulminant hepatic necrosis. The underlying mechanism of APAP hepatotoxicity involves mitochondrial dysfunction, including mitochondrial oxidant stress and the onset of mitochondrial permeability transition (MPT). Reactive oxygen species (ROS) play an important role in APAP-induced hepatotoxicity, and iron is a critical catalyst for ROS formation. This review summarizes the role of mitochondrial ROS formation in APAP hepatotoxicity and further focuses on the role of iron. Normally, hepatocytes take up Fe³⁺-transferrin bound to transferrin receptors via endocytosis. Concentrated into lysosomes, the controlled release of iron is required for the mitochondrial biosynthesis of heme and non-heme iron-sulfur clusters. After APAP overdose, the toxic metabolite, NAPQI, damages lysosomes, causing excess iron release and the mitochondrial uptake of Fe²⁺ by the mitochondrial calcium uniporter (MCU). NAPQI also inhibits mitochondrial respiration to promote ROS formation, including H₂O₂, with which Fe²⁺ reacts to form highly reactive •OH through the Fenton reaction. •OH, in turn, causes lipid peroxidation, the formation of toxic aldehydes, induction of the MPT, and ultimately, cell death. Fe²⁺ also facilitates protein nitration. Targeting pathways of mitochondrial iron movement and consequent iron-dependent mitochondrial ROS formation is a promising strategy to intervene against APAP hepatotoxicity in a clinical setting. Full article

Although lymphoma is the most frequent malignancy in common variable immunodeficiency (CVID), solid tumors, especially affected by oncogenic viruses, are not considered. Furthermore, in vitro genetic studies and cell cultures are not adequate for immune system and HBV interaction. We adopted a previously introduced clinical model of host–virus interaction (i.e., infectious process in immunodeficiency) for analysis of B cells and the specific IgG role (an observational study of a CVID patient who received intravenous immunoglobulin (IVIG). Suddenly, the patient deteriorated and a positive results of for HBs and HBV-DNA (369 × 10⁶ copies) were detected. Despite lamivudine therapy and IVIG escalation (from 0.3 to 0.4 g/kg), CT showed an 11 cm intrahepatic tumor (hepatocellular carcinoma). Anti-HBs were positive in time-lapse analysis (range 111–220 IU/mL). Replacement therapy intensification was complicated by an immune complex disease with renal failure. Fulminant HCC in CVID and the development of a tumor as the first sign is of interest. Unfortunately, treatment with hepatitis B immune globulins (HBIG) plays a major role in posttransplant maintenance therapy. Anti-HB substitution has not been proven to be effective, oncoprotective, nor safe. Therefore, immunosuppression in HBV-infected recipients should be carefully minimized, and patient selection more precise with the exclusion of HBV-positive donors. Our clinical model showed an HCC pathway with important humoral host factors, contrary to epidemiological/cohort studies highlighting risk factors only (e.g., chronic hepatitis). The lack of cell cooperation as well as B cell deficiency observed in CVID play a crucial role in high HBV replication, especially in carcinogenesis. Full article

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection—from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research. Full article

Acute liver failure (ALF) is a rare and specific form of severe hepatic dysfunction characterized by coagulopathy and hepatic encephalopathy in a patient with no known liver disease. ALF carries a high morbidity and mortality. Careful attention should be given to hemodynamics and metabolic parameters along with the active surveillance of infections. Timely transfer and supportive management are important in an intensive care unit in a liver transplant center. Identifying patients who will and will not improve with medical management and may need emergent liver transplantation is critical. In this review, we provide a comprehensive update on the etiology, diagnosis, and management of ALF. Full article

Chronic delta hepatitis is a global health problem. Although a smaller percentage of chronic HBV-infected patients are coinfected with the hepatitis delta virus, these patients have a higher risk of an accelerated progression to fulminant “delta hepatitis”, cirrhosis, hepatic decompensation, and hepatocellular carcinoma, putting a financial strain on the healthcare system and increasing the need for a liver transplant. Since its discovery, tremendous efforts have been directed toward understanding the intricate pathogenic mechanisms, discovering the complex viral replication process, the essential replicative intermediates, and cell division-mediated viral spread, which enables virion viability. The consideration of the interaction between HBV and HDV is crucial in the process of developing novel pharmaceuticals. Until just recently, interferon-based therapy was the only treatment available worldwide. This review aims to present the recent advancements in understanding the life cycle of HDV, which have consequently facilitated the development of innovative drug classes. Additionally, we will examine the antiviral strategies currently in phases II and III of development, including bulevirtide (an entry inhibitor), lonafarnib (a prenylation inhibitor), and REP 2139 (an HBsAg release inhibitor). Full article

The hepatitis E virus (HEV) is increasingly acknowledged as the primary cause of acute hepatitis. While most HEV infections are self-limiting, cases of chronic infection and fulminant hepatitis necessitate the administration of anti-HEV medications. However, there is a lack of specific antiviral drugs designed for HEV, and the currently available drug (ribavirin) has been associated with significant adverse effects. The development of innovative antiviral drugs involves targeting distinct steps within the viral life cycle: the early step (attachment and internalization), middle step (translation and RNA replication), and late step (virus particle formation and virion release). We recently established three HEV reporter systems, each covering one or two of these steps. Using these reporter systems, we identified various potential drug candidates that target different steps of the HEV life cycle. Through rigorous in vitro testing using our robust cell culture system with the genotype 3 HEV strain (JE03-1760F/P10), we confirmed the efficacy of these drugs, when used alone or in combination with existing anti-HEV drugs. This underscores their significance in the quest for an effective anti-HEV treatment. In the present review, we discuss the development of the three reporter systems, their applications in drug screening, and their potential to advance our understanding of the incompletely elucidated HEV life cycle. Full article

HEV is a single-stranded, positive RNA virus. The hepatitis E virus (HEV) is the causing agent of hepatitis, with a high prevalence rate in low-income countries due to poor sanitary conditions. It can exhibit acute, continuous, or extrahepatic consequences in immunocompromised individuals such as those undergoing organ transplantation and having HIV infection. HEV infection is either self limiting (silent), meaning the patient will possibly recover on his own, or symptomatic, causing acute liver injury or fulminant hepatitis and may eventually cause death. It can also cause chronic hepatitis that can progress to cirrhosis or recovery. Pregnancy-related HEV infection has an incidence rate of 30%. HEV escape from innate immunity, hormonal imbalances, defective monocyte–macrophage function, downregulation of the T-cell-mediated immune system, high cytokine production, nutritional factors, and socioeconomic conditions may play fundamental roles in the prevalence of HEV infection. It is necessary to take particular measures to reduce the incidence burden of HEV infection in high endemic locations as the incidence data, not the prevalence data, is more accurate at estimating disease dynamics. The purpose of this study is to throw light on several aspects of the hepatitis E virus and to discuss the incidence of HEV infection concerning other diseases. HEV molecular features, clinical features, epidemiology, extrahepatic manifestations, and multiple available diagnostics and treatment strategies for HEV are debated in the current review. Full article