Nationwide population-based study showed that the rotavirus vaccination had no impact on the incidence of biliary atresia in Korea

Genetic Contributions to Biliary Atresia: A Developmental Cholangiopathy

Biliary atresia (BA) is the most prevalent serious liver disease of infancy and childhood, and the principal indication for liver transplantation in pediatrics. BA is best considered as an idiopathic panbiliary cholangiopathy characterized by obstruction of bile flow and consequent cholestasis presenting during fetal and perinatal periods. While several etiologies have been proposed, each has significant drawbacks that have limited understanding of disease progression and the development of effective treatments. Recently, modern genetic analyses have uncovered gene variants contributing to BA, thereby shifting the paradigm for explaining the BA phenotype from an acquired etiology (e.g., virus, toxin) to one that results from genetically altered cholangiocyte development and function. Herein we review recently reported genetic contributions to BA, highlighting the enhanced representation of variants in biological pathways involving ciliary function, cytoskeletal structure, and inflammation. Finally, we blend these findings as a new framework for understanding the resultant BA phenotype as a developmental cholangiopathy.

Association between nurse staffing levels and rotavirus infection in neonatal intensive care units: A retrospective observational study

OBJECTIVES

To explore the relationship between nurse staffing levels and rotavirus infection in neonatal intensive care units.

RESEARCH METHODOLOGY

This study adopted a retrospective observational design with data from the Health Insurance Review and Assessment Service (2018) database in South Korea. Participants were 35,308 infants in neonatal intensive care units. Multiple logistic regression analyses were employed to examine the association between nurse staffing levels and rotavirus infection in neonatal intensive care units after adjusting for confounding variables such as patient and hospital-related characteristics.

RESULTS

A total of 1,514 (4.3%) infants developed rotavirus infection. Among the confounding variables, infectious disease, and being admitted from January to March and in December significantly increased the risk of rotavirus infection, whereas low birth weight, cardiovascular disorders, neonatal jaundice, receiving breastmilk, central line insertion, and ventilator usage significantly decreased the risk. Neonatal intensive care units with a grade 5 nurse staffing level (compared with grades 1-4) had a higher risk of rotavirus infection.

CONCLUSIONS

The results suggest that neonatal intensive care units with higher (vs lower) nurse staffing levels are associated with lower rotavirus infection rates among infants. High-risk infants are extremely susceptible to hospital-acquired infections, and more intensive nursing care that differs from that provided to adult or paediatric patients is required. Therefore, nurse staffing levels with less than a 2:1 patient-to-nurse ratio are needed to control and prevent rotavirus infection in neonatal intensive care units.

Update on Etiology and Pathogenesis of Biliary Atresia

Biliary atresia is a rare inflammatory sclerosing obstructive cholangiopathy that initiates in infancy as complete choledochal blockage and progresses to the involvement of intrahepatic biliary epithelium. Growing evidence shows that biliary atresia is not a single entity with a single etiology but a phenotype resulting from multifactorial events whose common path is obliterative cholangiopathy. The etiology of biliary atresia has been explained as resulting from genetic variants, toxins, viral infection, chronic inflammation or bile duct lesions mediated by autoimmunity, abnormalities in the development of the bile ducts, and defects in embryogenesis, abnormal fetal or prenatal circulation and susceptibility factors. It is increasingly evident that the genetic and epigenetic predisposition combined with the environmental factors to which the mother is exposed are potential triggers for biliary atresia. There is also an indication that a progressive thickening of the arterial middle layer occurs in this disease, suggestive of vascular remodeling and disappearance of the interlobular bile ducts. It is suggested that the hypoxia/ischemia process can affect portal structures in biliary atresia and is associated with both the extent of biliary proliferation and the thickening of the medial layer.

The impact of rotavirus vaccination in the prevalence of gastroenteritis and comorbidities among children after suboptimal rotavirus vaccines implementation in Taiwan: A population-based study

In Taiwan, rotavirus vaccination was implemented in 2006 in the private sector. The population-based impact of rotavirus vaccination on gastroenteritis and comorbidities of children remains under-investigated.We analyzed the annual prevalence of rotavirus-related disease, including gastroenteritis, convulsions, epilepsy, type I diabetes mellitus, intussusception, and biliary atresia among children under 5 years of age. Data were collected from Taiwan's National Health Insurance Research Database, a nationwide population-based database. A 16-year retrospective cohort study was conducted between 2000 and 2015.Among children <5 years of age, the prevalence of gastroenteritis decreased after 2012 (44,259.69 per 100 thousands) and remained lower through 2015 (39,931.11per 100 thousands, P < .001). The prevalence of convulsions rose steadily and significantly from 2007 (775.90 per 100 thousands) to 2015 (962.17 per 100 thousands, P < .001). The prevalence of epilepsy decreased significantly until reaching a nadir in 2013 (from 501.56 to 293.53 per 100 thousands, P < .001). The prevalence of biliary atresia tended upward, and surged suddenly in 2007 with a peak in 2013 (18.74 per 100 thousands). Among infants (<1 year of age) from 2000 to 2015, the prevalence of gastroenteritis declined steadily, and more rapidly after 2007 (22,513 to 17,285 per 100 thousands).In Taiwan, after introducing rotavirus vaccination, gastroenteritis in young children decreased, especially in infancy. However, gastroenteritis is still common in children, given other emerging pathogens. Our results highlight the impact of rotavirus vaccines on children's health in Taiwan and provide indications for future preventive medicine and healthcare strategies in children.

Congenital biliary atresia is correlated with disrupted cell junctions and polarity caused by Cdc42 insufficiency in the liver

Rationale: Congenital biliary atresia (BA) is a destructive obliterative cholangiopathy of neonates that affects both intrahepatic and extrahepatic bile ducts. However, the cause of BA is largely unknown.

Methods: We explored the cell junctions and polarity complexes in early biopsy BA livers by immunofluorescence staining and western blot. Cdc42, as a key cell junction and polarity regulator, was found dramatically decreased in BA livers. Therefore, in order to investigate the role of Cdc42 in BA development, we constructed liver-specific and tamoxifen induced cholangiocyte-specific Cdc42 deleted transgenic mice. We further evaluated the role of bile acid in aggravating biliary damage in Cdc42 insufficient mouse liver.

Results: We found a dramatic defect in the assembly of cell junctions and polarity complexes in both cholangiocytes and hepatocytes in BA livers. This defect was characterized by the disordered location of cell junction proteins, including ZO1, β-catenin, E-cadherin and claudin-3. Cdc42 and its active form, Cdc42-GTP, which serves as a small Rho GTPase to orchestrate the assembly of polarity complexes with Par6/Par3/αPKC, were substantially reduced in BA livers. Selective Cdc42 deficiency in fetal mouse cholangiocytes resulted in histological changes similar to those found in human BA livers, including obstruction in both the intra- and extrahepatic bile ducts, epithelial atrophy, and the disruption of cell junction and polarity complexes. A reduction in bile acids notably improved the histology and serological indices in Cdc42-mutant mice.

Conclusion: Our results illustrate that BA is closely correlated with the impaired assembly of cell junction and polarity complexes in liver cells, which is likely caused by Cdc42 insufficiency and aggravated by bile acid corrosion.

Rotavirus Infection and Cytopathogenesis in Human Biliary Organoids Potentially Recapitulate Biliary Atresia Development

There is substantial evidence indicating the possible involvement of rotavirus in biliary atresia (BA) development, at least in a subset of patients, but concrete proof remains lacking. In a mouse model, it has been well demonstrated that rotavirus can infect the biliary epithelium to cause biliary inflammation and obstruction, representing the pathogenesis of BA in humans. By using recently developed organoids technology, we now have demonstrated that human biliary organoids are susceptible to rotavirus infection, and this provokes active virus-host interactions and causes severe cytopathogenesis. Thus, our model recapitulates some essential aspects of BA development. Furthermore, we have demonstrated that antiviral drugs and neutralizing antibodies are capable of counteracting the infection and BA-like morphological changes, suggesting their potential for mitigating BA in patients.

Biliary atresia (BA) is a neonatal liver disease characterized by progressive fibroinflammatory obliteration of both intrahepatic and extrahepatic bile ducts. The etiologies of BA remain largely unknown, but rotavirus infection has been implicated at least for a subset of patients, and this causal relation has been well demonstrated in mouse models. In this study, we aim to further consolidate this evidence in human biliary organoids. We obtained seven batches of human biliary organoids cultured from fetal liver, adult liver, and bile duct tissues. We found that these organoids are highly susceptible and support the full life cycle of rotavirus infection in three-dimensional culture. The robust infection triggers active virus-host interactions, including interferon-based host defense mechanisms and injury responses. We have observed direct cytopathogenesis in organoids upon rotavirus infection, which may partially recapitulate the development of BA. Importantly, we have demonstrated the efficacy of mycophenolic acid and interferon alpha but not ribavirin in inhibiting rotavirus in biliary organoids. Furthermore, neutralizing antibody targeting rotavirus VP7 protein effectively inhibits infection in organoids. Thus, we have substantiated the causal evidence of rotavirus inducing BA in humans and provided potential strategies to combat the disease.

Investigation into multi-centre diagnosis and treatment strategies of biliary atresia in mainland China

BACKGROUND

Biliary atresia (BA) is an obstructive hepatobiliary disease which manifests during infancy. Kasai portoenterostomy (KPE) is the preferred operation for BA, supplemented with glucocorticoids, antibiotics, and choleretic agents. A great deal of research has been carried out regarding diagnosis, operation, and adjuvant therapies of BA, but no consensus had been reached. To understand the variation in diagnosis and treatment strategies of BA across mainland China and to help achieve a unified treatment strategy in the future, this investigation was carried out.

METHODS

This investigation was conducted via electronic questionnaire. The centres were divided into three groups based on their annual caseload: low (0-20)-, mid (21-40)-, and high (≥ 41)-volume group. Differences in the clinical practice among three groups were analyzed by Chi-square test and considered statistically significant at P < 0.05.

RESULTS

41 Centres from 26 different administrative regions were involved. The average age at KPE was mainly 51-60 days (39%, 16/41) and 61-70 days (32%, 13/41). The annual caseload was 0-20 patients in 17 centres, 21-40 patients in 11 centres, and > 40 patients in 13 centres. Preoperative ultrasound and intraoperative cholangiography were performed in all centres. Low-volume centres had a high proportion of MRI (P = 0.005), while the high-volume group had a high proportion of LSM (P = 0.015). Open KPE without liver mobilisation is the most common surgical procedure (71%, 29/41). Open KPE without liver mobilisation was more commonly used in low-volume group (P = 0.044), and laparoscopic KPE was mainly used in high-volume group (P = 0.011). The spur anti-reflux intestinal valve was performed in more than half of the centres (51%, 21/41). The length of the Roux-en-Y loop was ≥ 30 cm in the majority of centres (78%, 32/41). Glucocorticoids and antibiotics were used in most centres (90%, 37/41; 100%, 41/41) with marked variations in type, administration, dose, and duration. Oral ursodeoxycholic acid (UDCA) was used in 38 centres, in varying doses of 10-20 mg/kg/day. The duration of oral UDCA was over a year in 19 centres.

CONCLUSION

Mainland China has a large number of patients with biliary atresia. Diagnostic and surgical methods vary from centre to centre and are related to its caseload. In most centres, KPE is supplemented with glucocorticoids, antibiotics, and choleretic agents without a standard regimen.