Cytomegalovirus-associated biliary atresia

Brain imaging in children with neonatal cholestatic liver disease: A systematic review

AIM

To determine if children with neonatal cholestatic liver disease had concurrent and later findings on brain imaging studies that could be attributed and the cholestasis to contribute to the understanding of the impaired neuropsychological development.

METHODS

Ovid MEDLINE and EMBASE were searched on July 21, 2022, and updated on March 26, 2023. Studies with children under 18 years of age with neonatal cholestasis and a brain scan at the time of diagnosis or later in life were included. Excluded studies were non-English, non-human, reviews or conference abstracts. Data were extracted on demographics, brain imaging findings, treatment and outcome. The results were summarised by disease categories. Risk of bias was assessed using JBI critical appraisal tools.

RESULTS

The search yielded 12 011 reports, of which 1261 underwent full text review and 89 were eligible for inclusion. Haemorrhage was the most common finding, especially in children with bile duct obstruction, including biliary atresia. Some findings were resolved after liver transplantation.

CONCLUSION

Children with neonatal cholestasis had changes in brain imaging, which might play a role in impaired neuropsychological development, but longitudinal clinical research with structured assessment is needed to better qualify the aetiology of the impairment.

Immune-mediated cholangiopathies in children: the need to better understand the pathophysiology for finding the future possible treatment targets

Cholangiopathies are defined as focal or extensive damage of the bile ducts. According to the pathogenetic mechanism, it may be immune-mediated or due to genetic, infectious, toxic, vascular, and obstructive causes. Their chronic evolution is characterized by inflammation, obstruction of bile flow, cholangiocyte proliferation, and progression toward fibrosis and cirrhosis. Immune-mediated cholangiopathies comprise primary sclerosing cholangitis (PSC), autoimmune cholangitis and IgG4-associated cholangitis in adults and biliary atresia (BA), neonatal sclerosing cholangitis (NSC) in children. The main purpose of this narrative review was to highlight the similarities and differences among immune-mediated cholangiopathies, especially those frequent in children in which cholangiocyte senescence plays a key role (BA, NSC, and PSC). These three entities have many similarities in terms of clinical and histopathological manifestations, and the distinction between them can be hard to achieve. In BA, bile duct destruction occurs due to aggression of the biliary cells due to viral infections or toxins during the intrauterine period or immediately after birth. The consequence is the activation of the immune system leading to severe inflammation and fibrosis of the extrahepatic biliary tract, lumen stenosis, and impairment of the biliary flow. PSC is characterized by inflammation and fibrosis of intra- and extrahepatic bile ducts, leading to secondary biliary cirrhosis. It is a multifactorial disease that occurs because of genetic predisposition [human leukocyte antigen (HLA) and non-HLA haplotypes], autoimmunity (cellular immune response, autoantibodies, association with inflammatory bowel disease), environmental factors (infections or toxic bile), and host factors (intestinal microbiota). NSC seems to be a distinct subgroup of childhood PSC that appears due to the interaction between genetic predisposition (HLA B8 and DR3) and the disruption of the immune system, validated by elevated IgG levels or specific antibodies [antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA)]. Currently, the exact mechanism of immune cholangiopathy is not fully understood, and further data are required to identify individuals at high risk of developing these conditions. A better understanding of the immune mechanisms and pathophysiology of BA, NSC, and PSC will open new perspectives for future treatments and better methods of preventing severe evolution.

Detection of Cytomegalovirus Infection in Infants with Biliary Atresia: A Meta-analysis

Objectives  Biliary atresia (BA) is the most common indication of liver transplantation in children. Several reports attributed BA to both prenatal and perinatal etiologies, including a viral infection-induced autoimmune response that targets the bile ducts. Cytomegalovirus (CMV) remains the most common virus being linked to BA. This meta-analysis aimed to estimate to what extent CMV infection is detected in patients with BA.

Methods  This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases of MEDLINE, Embase, Scopus, WHO-Virtual Health Library (VHL), ScienceDirect, and Google Scholar were used for the systematic search. The risk of bias was assessed using the Newcastle–Ottawa scale. Random effects model was used to estimate the pooled prevalence estimate with the corresponding 95% confidence interval (CI) using Comprehensive Meta-Analysis Software version 3.3.

Results  A total of 19 studies that fulfilled the eligibility criteria were included in the meta-analysis. The total number of infants with BA was 630 patients, and the pooled overall prevalence of CMV infection among them was 25.4% (95% CI: 15.9%–38.0%). There was high heterogeneity among studies (I ²  = 85.1%, p  < .001), and subgroup analyses showed significant regional differences (X ²  = 48.9, p <.001). Data on the prognosis of CMV-associated BA were scarce and obtainable from few studies that suggested an association between detection of CMV infection and poor prognosis of BA.

Conclusions  The limited available data demonstrates that the rate of detection of CMV infection is high in infants with BA. There is still a need for large studies with appropriate controls for obtaining more reliable results about the various aspects of the association between CMV infection and BA.