Environmental Risk Factors of Pediatric-Onset Primary Sclerosing Cholangitis and Autoimmune Hepatitis

Liver transplant in primary sclerosing cholangitis: Current trends and future directions

Primary sclerosing cholangitis (PSC) is a chronic and progressive immune-mediated cholangiopathy causing biliary tree inflammation and scarring, leading to liver cirrhosis and end-stage liver disease. Diagnosis of PSC is challenging due to its nonspecific symptoms and overlap with other liver diseases. Despite the rising incidence of PSC, there is no proven medical therapy that can alter the natural history of the disease. While liver transplantation (LT) is the most effective approach for managing advanced liver disease caused by PSC, post-transplantation recurrence of PSC remains a challenge. Therefore, ongoing research aims to develop better therapies for PSC, and continued efforts are necessary to improve outcomes for patients with PSC. This article provides an overview of PSC's pathogenesis, clinical presentation, and management options, including LT trends and future aspects. It also highlights the need for improved therapeutic options and ethical considerations in providing equitable access to LT for patients with PSC. Additionally, the impact of liver transplant on the quality of life and psychological outcomes of patients with PSC is discussed. Ongoing research into PSC's pathogenesis and post-transplant recurrence is crucial for improved understanding of the disease and more effective treatment options.

Detection of Novel Biomarkers in Pediatric Autoimmune Hepatitis by Proteomic Profiling

Autoimmune hepatitis (AIH) is characterized by immune-mediated hepatocyte injury resulting in the destruction of liver cells, causing inflammation, liver failure, and fibrosis. Pediatric (AIH) is an autoimmune inflammatory disease that usually requires immunosuppression for an extended period. Frequent relapses after treatment discontinuation demonstrate that current therapies do not control intrahepatic immune processes. This study describes targeted proteomic profiling data in patients with AIH and controls. A total of 92 inflammatory and 92 cardiometabolic plasma markers were assessed for (i) pediatric AIH versus controls, (ii) AIH type 1 versus type 2, (iii) AIH and AIH-autoimmune sclerosing cholangitis overlapping syndrome and (iv) correlations with circulating vitamin D levels in AIH. A total of 16 proteins showed a nominally significant differential abundance in pediatric patients with AIH compared to controls. No clustering of AIH subphenotypes based on all protein data was observed, and no significant correlation of vitamin D levels was observed for the identified proteins. The proteins that showed variable expression include CA1, CA3, GAS6, FCGR2A, 4E-BP1 and CCL19, which may serve as potential biomarkers for patients with AIH. CX3CL1, CXCL10, CCL23, CSF1 and CCL19 showed homology to one another and may be coexpressed in AIH. CXCL10 seems to be the central intermediary link for the listed proteins. These proteins were involved in relevant mechanistic pathways for liver diseases and immune processes in AIH pathogenesis. This is the first report on the proteomic profile of pediatric AIH. The identified markers could potentially lead to new diagnostic and therapeutic tools. Nevertheless, considering the complex pathogenesis of AIH, more extensive studies are warranted to replicate and validate the present study's findings.

Overview of autoimmune liver disease: Prevalence, risk factors, and role of autoantibodies

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Possible role of the HMGB1 and RAGE inflammatory pathway in primary sclerosing cholangitis

BACKGROUND

Activation of the receptor for advanced glycation end products (RAGE) and its ligand High Mobility Group Box Protein 1 (HMGB1), a nuclear protein with proinflammatory properties, has been implicated in several inflammatory disorders.

OBJECTIVE

To analyse the influence of RAGE and HMGB1 signalling in patients with primary sclerosing cholangitis (PSC).

METHODS

Levels of HMGB1 and bile acid in serum and bile samples of 69 PSC patients and 32 controls were measured. Additionally, 640 patients with PSC and other liver diseases were analysed for the gain-of-function RAGE G82S SNP by PCR. Laboratory and clinical parameters were retrieved by chart review.

RESULTS

ELISA analysis showed significantly higher biliary HMGB1 concentrations in PSC patients (n=69, median 124,1 ng/ml) than in the control group (n=32, median 6,85 ng/ml, p<0,001). Median serum HMGB1 (n=22, median 2,4 ng/ml) was significantly lower than median biliary HMGB1 of the concomitant bile samples (n=22, median 151 ng/ml, p =0,001). There was no correlation of biliary HMGB1 levels with laboratory parameters or clinical end points. Analysis of the gain-of-function G82SSNP RAGE SNP in PSC patients showed 8 patients with heterozygote mutant alleles (8/324, 2,5%). Patients carrying the mutation developed more often dominant strictures of the large bile ducts (100.0% vs. 61.3%; p=0.04) and had reduced transplantation-free survival in the mutant allele group (p<0.001).

CONCLUSIONS

Biliary HMGB1 levels are elevated in PSC patients compared to controls and a gain-of-function SNP in RAGE is associated with development of dominant strictures and reduced survival in PSC patients.

Pathogenesis of Autoimmune Hepatitis-Cellular and Molecular Mechanisms

Pediatric autoimmune liver disorders include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is an idiopathic disease characterized by immune-mediated hepatocyte injury associated with the destruction of liver cells, causing inflammation, liver failure, and fibrosis, typically associated with autoantibodies. The etiology of AIH is not entirely unraveled, but evidence supports an intricate interaction among genetic variants, environmental factors, and epigenetic modifications. The pathogenesis of AIH comprises the interaction between specific genetic traits and molecular mimicry for disease development, impaired immunoregulatory mechanisms, including CD4+ T cell population and Treg cells, alongside other contributory roles played by CD8+ cytotoxicity and autoantibody production by B cells. These findings delineate an intricate pathway that includes gene to gene and gene to environment interactions with various drugs, viral infections, and the complex microbiome. Epigenetics emphasizes gene expression through hereditary and reversible modifications of the chromatin architecture without interfering with the DNA sequence. These alterations comprise DNA methylation, histone transformations, and non-coding small (miRNA) and long (lncRNA) RNA transcriptions. The current first-line therapy comprises prednisolone plus azathioprine to induce clinical and biochemical remission. Further understanding of the cellular and molecular mechanisms encountered in AIH may depict their impact on clinical aspects, detect biomarkers, and guide toward novel, effective, and better-targeted therapies with fewer side effects.

We Are Not Immune: Racial and Ethnic Disparities in Autoimmune Liver Diseases

Autoimmune liver diseases are attributed to a complex interplay of biologic, acquired, and environmental factors. Increased prevalence, later stage at presentation, worse response to standard therapy, and transplant-related disparities have all been reported in racial and ethnic minorities such as Black and Latinx patients with autoimmune liver diseases. While biology and inherited genetic predispositions may partly explain these disparities, definitive and universal genetic variations underlying these differences in outcomes have not been defined. Nonetheless, socioeconomic status, access to health care, environmental and societal factors, and implicit provider bias can all contribute to poor patient outcomes. There remains an unmet need to understand and mitigate the factors contributing to health inequity in autoimmune liver diseases. In this review, we summarize the data on racial and ethnic disparities in presentation, treatment response, and outcomes pertaining to autoimmune liver diseases in minority populations, on the premise that understanding disparities is the first step toward reaching health equity.

Recurrence of Primary Sclerosing Cholangitis After Liver Transplant in Children: An International Observational Study

BACKGROUND AND AIMS

Recurrent primary sclerosing cholangitis (rPSC) following liver transplant (LT) has a negative impact on graft and patient survival; little is known about risk factors for rPSC or disease course in children.

APPROACH AND RESULTS

We retrospectively evaluated risk factors for rPSC in 140 children from the Pediatric PSC Consortium, a multicenter international registry. Recipients underwent LT for PSC and had >90 days of follow-up. The primary outcome, rPSC, was defined using Graziadei criteria. Median follow-up after LT was 3 years (interquartile range 1.1-6.1). rPSC occurred in 36 children, representing 10% and 27% of the subjects at 2 years and 5 years following LT, respectively. Subjects with rPSC were younger at LT (12.9 vs. 16.2 years), had faster progression from PSC diagnosis to LT (2.5 vs. 4.1 years), and had higher alanine aminotransferase (112 vs. 66 IU/L) at LT (all P < 0.01). Inflammatory bowel disease was more prevalent in the rPSC group (86% vs. 66%; P = 0.025). After LT, rPSC subjects had more episodes of biopsy-proved acute rejection (mean 3 vs. 1; P < 0.001), and higher prevalence of steroid-refractory rejection (41% vs. 20%; P = 0.04). In those with rPSC, 43% developed complications of portal hypertension, were relisted for LT, or died within 2 years of the diagnosis. Mortality was higher in the rPSC group (11.1% vs. 2.9%; P = 0.05).

CONCLUSIONS

The incidence of rPSC in this cohort was higher than previously reported, and was associated with increased morbidity and mortality. Patients with rPSC appeared to have a more aggressive, immune-reactive phenotype. These findings underscore the need to understand the immune mechanisms of rPSC, to lay the foundation for developing new therapies and improve outcomes in this challenging population.

Impact of paediatric onset primary sclerosing cholangitis on clinical course and outcome of inflammatory bowel disease: a case-control population-based study in Finland

Introduction and aim: The aim of this study was to investigate the outcome of a paediatric onset of inflammatory bowel disease (IBD) in a cohort of subjects with primary sclerosing cholangitis (PSC) and in a matched-age population-based control group without PSC. Methods: We identified 28 IBD-PSC cases (median age at IBD diagnosis 12.5 years, 25-75th: 10-16 years) and selected three IBD controls for each case matched for age and year of IBD diagnosis. All data regarding the gastrointestinal tract and liver were collected at diagnosis and at last follow-up (median 15 years). Results: At diagnosis the prevalence of pancolitis was similar between the groups (78% and 79%, respectively p = -.30), but histologic inflammation was milder in IBD-PSC (61% vs 30%, p = .06). At last follow-up (median age 29 years) pancolitis was less frequent (6% and 33%, respectively p = .04) and the remission higher (76% and 47%, respectively p = .08) in IBD-PSC patients than in IBD patients. Panproctolectomy (32% in IBD-PSC and 34% in IBD, p = 1.0) and the rate of pouchitis (62% and 70%, respectively p = .8) were similar. Conclusions: The outcome of paediatric onset IBD in patients with PSC in adulthood seems to be comparable to those with IBD only.

National incidence of autoimmune liver diseases and its relationship with the human development index

Objective

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH) and immunoglobulin G4 related cholangitis represent the major autoimmune liver diseases (AILD). However, the relationship between AILD incidence and socioeconomic development levels is yet to be explored.

Results

A total of 43 studies were included. There was a positive but not significant correlation between the PBC incidence and HDI on a global level (r=0.348, P=0.082). However, in Europe, a significantly positive correlation existed between the PBC incidence and HDI (r=0.455, P=0.044). No statistical correlation between PSC incidence and HDI was observed (r=0.116, P=0.706). The incidence of AIH revealed a positive correlation with the national HDI both globally (r=0.638, P=0.014) and in Europe (r=0.644, P=0.045). Moreover, the PBC incidence demonstrated a positive correlation with the health index (r=0.422, P=0.036), but a negative correlation with the education index (r= −0.650, P<0.01). Moreover, the income index presented a positive correlation with both the PSC incidence (r=0.599, P=0.031) and the AIH incidence (r=0.649, P=0.012).

Methods

PubMed was searched to identify relevant epidemiological studies on AILD. The human development index (HDI) was applied as an indicator for socioeconomic development. HDI data were obtained and calculated based on the 2014 Human Development Report. Pearson coefficient and linear regression analysis were conducted to estimate the correlation between incidence and HDI.

Conclusions

There is positive association between the national incidence of AILD and the socioeconomic status, as measured by HDI. In less-developed countries, the incidence of AILD, especially PBC and AIH, might be less common.

Human leucocyte antigens B*08, DRB1*03 and DRB1*13 are significantly associated with autoimmune liver and biliary diseases in Finnish children

AIM

The human leucocyte antigen (HLA) allele and haplotype frequencies of the Finnish population are unique because of the restricted and homogenous gene population. There are no published data on HLA genotype associations in paediatric autoimmune liver diseases in Scandinavia. This study characterised the HLA genotypes of children with autoimmune liver or biliary disease in Finland.

METHODS

The study cohort comprised 19 paediatric patients (13 female) aged three years to 15 years treated for autoimmune liver or biliary disease at the Children's Hospital, Helsinki University Hospital, between 2000 and 2011, and followed up for four years and three months to 14.6 years. We genotyped HLA-B and HLA-DRB1 in the children, and the HLA antigen frequencies were compared with 19 807 records from the Finnish Bone Marrow Donor Registry.

RESULTS

All paediatric patients with autoimmune liver or biliary disease had either autoimmune HLA haplotype B*08;DRB1*03 or DRB1*13. These were significantly more common among patients with autoimmune hepatitis, primary sclerosing cholangitis and autoimmune hepatitis/primary sclerosing cholangitis overlap syndrome than the Finnish control population. HLA RB1*04 was not found in the study cohort.

CONCLUSION

Our study found that B*08, DRB1*03 and DRB1*13 were significantly associated with autoimmune liver and biliary diseases in Finnish paediatric patients.