Prevalence of Sclerosing Cholangitis Detected by Magnetic Resonance Cholangiography in Patients With Long-term Inflammatory Bowel Disease

Hepatic immune regulation and sex disparities

Chronic liver disease is a major cause of morbidity and mortality worldwide. Epidemiology, clinical phenotype and response to therapies for gastrointestinal and liver diseases are commonly different between women and men due to sex-specific hormonal, genetic and immune-related factors. The hepatic immune system has unique regulatory functions that promote the induction of intrahepatic tolerance, which is key for maintaining liver health and homeostasis. In liver diseases, hepatic immune alterations are increasingly recognized as a main cofactor responsible for the development and progression of chronic liver injury and fibrosis. In this Review, we discuss the basic mechanisms of sex disparity in hepatic immune regulation and how these mechanisms influence and modify the development of autoimmune liver diseases, genetic liver diseases, portal hypertension and inflammation in chronic liver disease. Alterations in gut microbiota and their crosstalk with the hepatic immune system might affect the progression of liver disease in a sex-specific manner, creating potential opportunities for novel diagnostic and therapeutic approaches to be evaluated in clinical trials. Finally, we identify and propose areas for future basic, translational and clinical research that will advance our understanding of sex disparities in hepatic immunity and liver disease.

Prevalence and clinical profiles of primary sclerosing cholangitis in China: Data from electronic medical records and systematic literature retrieval

BACKGROUND & AIMS

Epidemiology of primary sclerosing cholangitis (PSC) is lacking in China. We aimed to estimate the period prevalence and depict the clinical features of PSC in China.

METHODS

We identified and included PSC cases between 2000 and 2023 from two sources: electronic medical records (EMR) and systematical literature retrieval (SLR). The period prevalence of PSC was estimated by the multiplier method. Rate ratios (RRs) for PSC prevalence in relation to macroeconomic indicators were calculated by the negative binomial regression model.

RESULTS

A total of 1358 PSC cases were retrieved from 299 hospitals (162 from EMR and 1196 from SLR). Males accounted for 55.7 % of the PSC cases and 25.7 % had concomitant inflammatory bowel disease (IBD). The estimated period prevalence of PSC from 2000 to 2023 was 2.36 (95 % CI: 1.82, 3.34) per 100,000. Males had a numerically higher PSC prevalence than females (2.56, 95 % CI: 1.97, 3.63 vs. 2.14, 95 % CI: 1.65, 3.04 per 100,000). The highest prevalence of PSC was in East China at 4.87 (95 % CI: 3.44, 7.18) per 100,000, followed by North China at 2.94 (95 % CI: 2.33, 3.74) per 100,000, and the lowest in South China at 0.92 (95 % CI: 0.66, 1.30) per 100,000. Regional per capita GDP (RR 1.65, 95 % CI: 1.03, 2.65) and healthcare expenditure (RR 1.94, 95 % CI: 1.13, 3.38) were identified to be associated with PSC prevalence.

CONCLUSION

Our study showed the estimated PSC prevalence varied within China, but was generally lower than that in Western countries.

Quantitative MRCP and metrics of bile duct disease over time in patients with primary sclerosing cholangitis: A prospective study

BACKGROUND

Imaging markers of biliary disease in primary sclerosing cholangitis (PSC) have potential for use in clinical and trial disease monitoring. Herein, we evaluate how quantitative magnetic resonance cholangiopancreatography (MRCP) metrics change over time, as per the natural history of disease.

METHODS

Individuals with PSC were prospectively scanned using non-contrast MRCP. Quantitative metrics were calculated using MRCP+ post-processing software to assess duct diameters and dilated and strictured regions. Additionally, a hepatopancreatobiliary radiologist (blinded to clinical details, biochemistry and quantitative biliary metrics) reported each scan, including ductal disease assessment according to the modified Amsterdam Cholangiographic Score (MAS).

RESULTS

At baseline, 14 quantitative MRCP+ metrics were found to be significantly different in patients with PSC (N = 55) compared to those with primary biliary cholangitis (N = 55), autoimmune hepatitis (N = 57) and healthy controls (N = 18). In PSC specifically, baseline metrics quantifying the number of strictures and the number and length of bile ducts correlated with the MAS, transient elastography and serum ALP values (p < 0.01 for all correlations). Over a median 371-day follow-up (range: 364-462), 29 patients with PSC underwent repeat MRCP, of whom 15 exhibited quantitative changes in MRCP+ metrics. Compared to baseline, quantitative MRCP+ identified an increasing number of strictures over time (p < 0.05). Comparatively, no significant differences in biochemistry, elastography or the MAS were observed between timepoints. Quantitative MRCP+ metrics remained stable in non-PSC liver disease.

CONCLUSION

Quantitative MRCP+ identifies changes in ductal disease over time in PSC, despite stability in biochemistry, liver stiffness and radiologist-derived cholangiographic assessment (trial registration: ISRCTN39463479).

Identifying a therapeutic window of opportunity for people living with primary sclerosing cholangitis: Embryology and the overlap of inflammatory bowel disease with immune-mediated liver injury

Primary sclerosing cholangitis (PSC) is a variably progressive, fibrosis-causing autoimmune disorder of the intrahepatic and extrahepatic bile ducts of unclear etiology. PSC is commonly (in 60%-90% of cases) associated with an inflammatory bowel disease (IBD) like PSC-IBD and less commonly with an autoimmune hepatitis (AIH) like PSC-AIH or AIH-overlap disorder. Hepatologists and Gastroenterologists often consider these combined conditions as distinctly different from the classical forms in isolation. Here, we review recent epidemiologic observations and highlight that PSC-IBD and PSC-AIH overlap appear to represent aspects of a common PSC clinico-pathological pathway and manifest in an age-of-presentation-dependent manner. Particularly from the pediatric experience, we hypothesize that all cases of PSC likely originate from a complex "Early PSC"-"IBD"-"AIH" overlap in which PSC defines the uniquely and variably associated "AIH" and "IBD" components along an individualized lifetime continuum. We speculate that a distinctly unique, "diverticular autoimmunity" against the embryonic cecal- and hepatic diverticulum-derived tissues may be the origin of this combined syndrome, where "AIH" and "IBD" variably commence then variably fade while PSC progresses with age. Our hypothesis provides an explanation for the age-dependent variation in the presentation and progression of PSC. This is critical for the optimal targeting of studies into PSC etiopathogenesis and emphasizes the concept of a "developmental window of opportunity for therapeutic mitigation" in what is currently recognized as an irreversible disease process. The discovery of such a window would be critically important for the targeting of interventions, both the administration of current therapies and therapeutic trial planning.

The wedish initiative for the stdy of ary sclerosing cholangitis (SUPRIM)

Background

Despite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well-characterised prospective resources is an important contributing factor to the current situation.

Methods

We here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10-year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011-April 2016).

Findings

Out of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided.

Interpretation

We envision the SUPRIM cohort as an open-access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040.

Funding

This work was supported by the Swedish Cancer Society, Stockholm County Council, and the Cancer Research Funds of Radiumhemmet.

Prevalence of Hepatobiliary Manifestations in Inflammatory Bowel Disease: A GRADE Assessed Systematic Review and Meta-Analysis of more than 1.7 Million Patients

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] comprises an immune-mediated group of chronic gastrointestinal disorders. Patients with IBD may experience extraintestinal manifestations, such as hepatobiliary complications. This meta-analysis aims to assess the prevalence of different hepatic manifestations in IBD patients.

METHODS

For this systematic review and meta-analysis, PubMed, Scopus, Web of Science, and Embase were searched until July 20, 2022, by specifying keywords for IBD, hepatic manifestations, and study type. Full texts of cohort studies in English that examined the prevalence of different hepatic manifestations were included in this study. The primary outcome was the overall prevalence of hepatic manifestations in IBD patients. For the statistical analysis, a proportion by random effect model meta-analysis was performed. The registration number for the protocol of this study in PROSPERO is CRD42022369595.

RESULTS

From the 4421 articles retrieved from the primary search, 118 met the inclusion criteria and were included in the final analysis. After a pooled analysis of 1 729 128 patients, the overall prevalence of hepatic manifestations was 3.49% (95% confidence interval [CI]: 3.31-3.68%; I2: 99.55%). The pooled prevalence of non-alcoholic fatty liver disease in 228 216 patients was 26.1% [95% CI: 22.1-30.2%; I2: 99.018%]. After pooled analysis of 9642 patients, the prevalence of primary sclerosing cholangitis was 1.67% [95% CI: 1.47-1.88%; I2: 99.10%]. The pooled prevalence of biliary stones was 4.1% [95% CI: 3.6-4.7%; I2: 97.43%]. Autoimmune hepatitis (0.51% [95% CI: 0.26-0.75%]; I2: 85.36%) and portal vein thrombosis (0.21% [95% CI: 0.08-0.33%]; I2: 97.95%) are considered as rare manifestations.

CONCLUSION

This study summarizes the prevalence and importance of different hepatic manifestations in IBD patients. These findings are crucial for the management of extraintestinal manifestations, especially hepatic manifestations, in IBD patients.

Phenotypes of Primary Sclerosing Cholangitis and Differential Diagnosis

Primary sclerosing cholangitis is a heterogenous immune-mediated disorder characterized by chronic inflammation and stricturing of the bile ducts. Though the driving pathophysiologic mechanisms remain elusive, there are several observed clinical phenotypes of the disease. The distribution of bile duct involvement, presence of concomitant inflammatory bowel disease, significant infiltration of IgG4-positive plasma cells, and overlapping features with other autoimmune disease has significant implications for prognosis and treatment. As there remains no pathognomonic finding for primary sclerosing cholangitis, a broad differential diagnosis and extensive evaluation of other underlying causes is critical to appropriate management.

Whole blood RNA sequencing identifies transcriptional differences between primary sclerosing cholangitis and ulcerative colitis

Background & Aims

Genetic and microbiome studies across patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) have indicated that UC in PSC is a separate disease entity to primary UC, but expression studies for PSC are lacking.

Methods

We conducted whole blood RNA sequencing experiments for 495 patients with UC, 220 patients with PSC (including 177 with UC), and 320 healthy controls from Germany and Norway. Differential expression analyses, gene ontology and coexpression analyses and random forest machine learning were performed to identify genes, ontologies and transcriptional features that discriminate diagnoses.

Results

The blood transcriptome in UC and PSC is dominated by neutrophil activation genes (e.g. S100A12). In UC, but not in PSC (neither PSC alone nor patients with an additional diagnosis of UC [PSC/UC]), ribosomal, mitochondrial, and energy metabolism genes are upregulated in conjunction with antibody transcript expression (MZB1, IGJ). In PSC, there is an increase in modules related to apoptosis and expression of genes of interferon-I-related ontologies. Random forest analysis could poorly discriminate PSC alone from PSC/UC (AUROC 0.56), but could discriminate PSC, UC, and controls with high accuracy (AUROC UC vs. controls 0.95, PSC vs. controls 0.88, UC vs. PSC 0.986). The main coexpression modules relevant for distinguishing PSC, UC, and controls are enriched in neutrophil degranulation and antibody production genes.

Conclusions

Supported by machine learning results, PSC and UC appear to be separate entities on a molecular level, while PSC/UC and PSC are indistinguishable.

Impact and implications

Clinical and genetic studies suggest that the colitis-like symptoms in primary sclerosing cholangitis (PSC) represent a different disease entity from primary ulcerative colitis (UC). The present study supports this assumption with transcriptomic data from whole blood and describes notable differences in gene expression between primary UC and PSC, providing insights into the still unclear pathophysiology of both diseases. These findings are of interest to scientists seeking to decipher the molecular pathophysiology of both diseases and provide evidence that a redefinition of the PSC-UC phenotype should be considered. The study practically supports future molecular research by providing a large transcriptomic whole blood reference cohort.

Diagnostic Tests in Primary Sclerosing Cholangitis: Serology, Elastography, Imaging, and Histology

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by progressive inflammation and fibrosis of the biliary tree leading to biliary strictures, cholangitis, and cirrhosis. Early in presentation, patients may have normal liver tests, though over time develop a cholestatic pattern of liver injury. Diagnosis is made radiographically with magnetic resonance or endoscopic cholangiography. While several autoantibodies are associated with PSC, none have proven to have adequate diagnostic utility. Liver biopsy is rarely recommended unless to evaluate for small-duct PSC or overlap syndrome. Elastography, in various forms, is an effective, non-invasive modality to evaluate liver fibrosis in PSC.

Primary Sclerosing Cholangitis: Diagnostic Criteria

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intra- and/or extrahepatic bile ducts leading to the formation of multifocal strictures alternated to bile duct dilatations. The diagnosis of the most common subtype of the disease, the large duct PSC, is based on the presence of elevation of cholestatic indices, the association of typical cholangiographic findings assessed by magnetic resonance cholangiography and the exclusion of causes of secondary sclerosing cholangitis. Liver biopsy is not routinely applied for the diagnosis of large duct PSC but is mandatory in the case of suspicion of small duct PSC or overlap with autoimmune hepatitis.

Microbial exposure during early life regulates development of bile duct inflammation

OBJECTIVES

The early life microbiome has been linked to inflammatory diseases in adulthood and a role for the microbiome in bile duct inflammation is supported by both human and murine studies. We utilized the NOD.c3c4 mouse model that develops a spontaneous immune-driven biliary disease with a known contribution of the microbiome to evaluate the temporal effects of the early life microbiome.

MATERIALS AND METHODS

Germ-free (GF) NOD.c3c4 mice were conventionalized into a specific pathogen free environment at birth (conventionally raised, CONV-R) or at weaning (germ-free raised, GF-R) and compared with age and gender-matched GF and conventional (CONV) NOD.c3c4 mice. At 9 weeks of age, liver pathology was assessed by conventional histology and flow cytometry immunophenotyping.

RESULTS

Neonatal exposure to microbes (CONV-R) increased biliary inflammation to similar levels as regular conventional NOD.c3c4 mice, while delayed exposure to microbes (GF-R) restrained the biliary inflammation. Neutrophil infiltration was increased in all conventionalized mice compared to GF. An immunophenotype in the liver similar to CONV was restored in both CONV-R and GF-R compared to GF mice displaying a proportional increase of B cells and reduction of T cells in the liver.

CONCLUSIONS

Microbial exposure during early life has a temporal impact on biliary tract inflammation in the NOD.c3c4 mouse model suggesting that age-sensitive interaction with commensal microbes have long-lasting effects on biliary immunity that can be of importance for human cholangiopathies.

Inflammatory bowel disease and primary sclerosing cholangitis: One disease or two?

Primary sclerosing cholangitis (PSC) was declared one of the biggest unmet needs in hepatology during International Liver Congress 2016 in Berlin. Since then, not much has changed unfortunately, largely due to the still elusive pathophysiology of the disease. One of the most striking features of PSC is its association with inflammatory bowel disease (IBD), with the majority of patients with PSC being diagnosed with extensive colitis. This review describes the epidemiology of IBD in PSC, its specific phenotype, complications and potential pathophysiological mechanisms connecting the two diseases. Whether PSC is merely an extra-intestinal manifestation of IBD or if PSC and IBD are two distinct diseases that happen to share a common susceptibility that leads to a dual phenotype is debated. Implications for the management of the two diseases together are also discussed. Overall, this review summarises the available data in PSC-IBD and discusses whether PSC and IBD are one or two disease(s).

Elevated Liver Fibrosis Progression in Isolated PSC Patients and Increased Malignancy Risk in a PSC-IBD Cohort: A Retrospective Study

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease often associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (CU), and rarely with Crohn's disease (CD). Various long-term analyses show different rates of cancer and the need for orthotopic liver transplantation (OLT) in patients with isolated PSC and with concomitant IBD, respectively. However, data on the detailed course of PSC with or without IBD are limited. We aimed to analyze the clinical disease course of PSC patients without IBD compared to PSC patients with UC and CD, respectively. A retrospective data analysis of patients with isolated PSC (n = 41) and of patients with concomitant IBD (n = 115) was performed. In detail, PSC disease characteristics including occurrence of dominant stenoses, liver cirrhosis, OLT and malignancy, as well as the temporal course of PSC activity and disease progression, were analyzed. A multivariable Cox regression model and a Fine-Gray competing risk model were further used for the independent risk factor analysis of cirrhosis development and OLT. Patients with isolated PSC were significantly older at first diagnosis than patients with PSC-IBD (39 vs. 28 years, p = 0.02). A detailed analysis of the course of PSC revealed a faster PSC progression after initial diagnosis in isolated PSC patients compared to PSC-IBD including significantly earlier diagnosis of dominant stenoses (29 vs. 74 months, p = 0.021) and faster progression to liver cirrhosis (38 vs. 103 months, p = 0.027). Patients with isolated PSC have a higher risk of developing cirrhosis than patients with PSC-IBD (Gray's test p = 0.03). OLT was more frequently performed in male patients with isolated PSC compared to males with coincident IBD (48% (n = 13) vs. 33% (n = 25), p = 0.003). Colorectal carcinoma was significantly more often diagnosed in patients with PSC-IBD than in isolated PSC (8.7% vs. 0%, p = 0.042). Patients with isolated PSC seem to have a different clinical course of disease than PSC patients with concomitant IBD characterized by a more pro-fibrotic disease course with earlier onset of liver cirrhosis and dominant stenosis but with less malignancy. These data may be interpreted as either a more progressive disease course of isolated PSC or a later diagnosis of the disease at an advanced disease stage. The different clinical courses of PSC and the underlying mechanisms of the gut-liver axis need further attention.

Low prevalence of primary sclerosing cholangitis in patients with inflammatory bowel disease in India

BACKGROUND/AIMS

Primary sclerosing cholangitis (PSC) represents the most common hepatobiliary extraintestinal manifestation of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). Limited data exist on PSC in patients with IBD from India. We aimed to assess the prevalence and disease spectrum of PSC in Indian patients with IBD.

METHODS

Database of IBD patients at 5 tertiary care IBD centers in India were analyzed retrospectively. Data were extracted and the prevalence of PSC-IBD was calculated.

RESULTS

Forty-eight patients out of 12,216 patients with IBD (9,231 UC, 2,939 CD, and 46 IBD unclassified) were identified to have PSC, resulting in a prevalence of 0.39%. The UC to CD ratio was 7:1. Male sex and pancolitis (UC) or colonic CD were more commonly associated with PSC-IBD. The diagnosis of IBD preceded the diagnosis of PSC in most of the patients. Majority of the patients were symptomatic for liver disease at diagnosis. Eight patients (16.66%) developed cirrhosis, 5 patients (10.41%), all UC, developed malignancies (3 colorectal cancer [6.25%] and 2 cholangiocarcinoma [4.16%]), and 3 patients died (2 decompensated liver disease [4.16%] and 1 cholangiocarcinoma [2.08%]) on follow-up. None of the patients mandated surgical therapy for IBD.

CONCLUSIONS

Concomitant PSC in patients with IBD is uncommon in India and is associated with lower rates of development of malignancies.

NOTCH signalling - a core regulator of bile duct disease?

The Notch signalling pathway is an evolutionarily conserved mechanism of cell-cell communication that mediates cellular proliferation, fate determination and maintenance of stem/progenitor cell populations across tissues. Although it was originally identified as a critical regulator of embryonic liver development, NOTCH signalling activation has been associated with the pathogenesis of a number of paediatric and adult liver diseases. It remains unclear, however, what role NOTCH actually plays in these pathophysiological processes and whether NOTCH activity represents the reactivation of a conserved developmental programme that is essential for adult tissue repair. In this Review, we explore the concepts that NOTCH signalling reactivation in the biliary epithelium is a reiterative and essential response to bile duct damage and that, in disease contexts in which biliary epithelial cells need to be regenerated, NOTCH signalling supports ductular regrowth. Furthermore, we evaluate the recent literature on NOTCH signalling as a critical factor in progenitor-mediated hepatocyte regeneration, which indicates that the mitogenic role for NOTCH signalling in biliary epithelial cell proliferation has also been co-opted to support other forms of epithelial regeneration in the adult liver.

D-amino Acids Ameliorate Experimental Colitis and Cholangitis by Inhibiting Growth of Proteobacteria: Potential Therapeutic Role in Inflammatory Bowel Disease

BACKGROUND & AIMS

D-amino acids, the chiral counterparts of protein L-amino acids, were primarily produced and utilized by microbes, including those in the human gut. However, little was known about how orally administered or microbe-derived D-amino acids affected the gut microbial community or gut disease progression.

METHODS

The ratio of D- to L-amino acids was analyzed in feces and blood from patients with ulcerative colitis (UC) and healthy controls. Also, composition of microbe was analyzed from patients with UC. Mice were treated with D-amino acid in dextran sulfate sodium colitis model and liver cholangitis model.

RESULTS

The ratio of D- to L-amino acids was lower in the feces of patients with UC than that of healthy controls. Supplementation of D-amino acids ameliorated UC-related experimental colitis and liver cholangitis by inhibiting growth of Proteobacteria. Addition of D-alanine, a major building block for bacterial cell wall formation, to culture medium inhibited expression of the ftsZ gene required for cell fission in the Proteobacteria Escherichia coli and Klebsiella pneumoniae, thereby inhibiting growth. Overexpression of ftsZ restored growth of E. coli even when D-alanine was present. We found that D-alanine not only inhibited invasion of pathological K. pneumoniae into the host via pore formation in intestinal epithelial cells but also inhibited growth of E. coli and generation of antibiotic-resistant strains.

CONCLUSIONS

D-amino acids might have potential for use in novel therapeutic approaches targeting Proteobacteria-associated dysbiosis and antibiotic-resistant bacterial diseases by means of their effects on the intestinal microbiota community.

[Sex-specific differences in gastroenterological diseases]

Diseases of the gastrointestinal tract present with substantial sex differences that have a potential impact on patient outcome. This fact is not sufficiently addressed either in basic research or in clinical studies. For example, most animal studies utilize male animals. Despite differences in incidence, sex may affect complication rates, prognosis, or therapeutic response. The incidence of gastrointestinal cancers is frequently higher in males, but this observation cannot solely rely on a distinct risk behaviour. Here, differences in immune response and p53 signalling may be factors responsible for this finding. Nevertheless, taking sex differences into account and improving our understanding of relevant mechanisms is crucial and will most likely have a substantial impact on disease outcome. This overview aims to highlight sex differences in the context of various gastroenterological diseases, primarily to enhance awareness. Attention to sex-specific differences is essential to improve individualized treatment.

Primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD): a condition exemplifying the crosstalk of the gut-liver axis

The close relationship between primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) provides a good opportunity to comprehend the gut-liver axis. The gut and the liver have reciprocal interactions, including how gut inflammation influences the liver through immune cells and the microbiota and how the microbiota in the gut modifies bile acids, which are produced and secreted from the liver. PSC-IBD shows distinct clinical findings from classical IBD. In addition, a distinct genetic predisposition and unique microbiota composition suggest that PSC-IBD is an independent disease entity. Understanding the pathogenesis of PSC-IBD helps to develop novel and effective therapeutic agents. Given the high risk of malignancies associated with PSC-IBD, it is critical to identify patients at high risk and implement appropriate surveillance and monitoring strategies. In this review, we provide an overview of PSC-IBD, which exemplifies the gut-liver axis.

Recent Advances in the Management of Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by fibroinflammatory damage to the biliary tree, typically in the setting of inflammatory bowel disease, with an increased risk of liver failure and cholangiocarcinoma. A complex pathophysiology, heterogeneity in clinical features, and the rare nature of the disease have contributed to the lack of effective therapy to date. However, recent innovations in the characterization and prognostication of patients with PSC, in addition to new tools for medical management and emerging pharmacologic agents, give rise to the potential for meaningful progress in the next several years. This review summarizes current concepts in PSC and highlights particular areas in need of further study.

Incidence of cancer in patients with ulcerative colitis 30 years after diagnosis (the IBSEN study)

OBJECTIVES

Patients with ulcerative colitis (UC) have shown an increased risk for colorectal cancer, hepatobiliary, hematologic, and skin cancers, but updated long-term data is needed. This study aimed to estimate the risk of cancer in patients with UC compared to the general Norwegian population, in a population-based cohort (the IBSEN study), 30 years after diagnosis; and to identify possible risk factors associated with cancer.

METHODS

The IBSEN cohort prospectively included all incident patients between 1990 and 1993. Cancer incidence data were obtained from the Cancer Registry of Norway. The overall and cancer-specific hazard ratios (HR) were modelled using Cox regression. Standardized incidence ratios were estimated compared to the general population.

RESULTS

In total, the cohort included 519 patients, and 83 cases were diagnosed with cancer. There was no statistically significant difference in the overall cancer risk (HR = 1.01, 95% CI: [0.79-1.29]) and colorectal cancer risk (HR = 1.37, 95% CI: [0.75-2.47]) between patients and controls. The incidence of biliary tract cancer was higher than expected (SIR = 9.84, 95%CI: [3.19-20.15]), especially when UC patients suffered from primary sclerosing cholangitis. Male UC patients were also more at risk of being diagnosed with hematologic malignancies (HR = 3.48, 95% CI: [1.55-7.82]). Being prescribed thiopurines was associated with a higher risk of cancer (HR = 2.03, 95% CI: [1.02-4.01]).

CONCLUSIONS

At 30 years after diagnosis, the risk of all cancer in patients with UC was not significantly increased compared with the general population. However, the risks of biliary tract cancer and hematologic cancers were increased, particularly in male patients.

Incidence and adverse clinical events of primary sclerosing cholangitis with ulcerative colitis

PURPOSE

The aim of this study was to conduct a nationwide population-based study to estimate the incidence of primary sclerosing cholangitis in patients with ulcerative colitis (UC-PSC) and investigate healthcare use, medication use, surgery, cancer, and death as adverse clinical events of UC-PSC.

METHODS

We identified incident cases of UC with (UC-PSC) or without PSC (UC-alone) between 2008 and 2018 using health insurance claims data in Korea. Univariate (crude hazard ratio (HR)) and multivariate analyses were performed to compare the risk of adverse clinical events between groups.

RESULTS

A total of 14,406 patients with UC using population-based claims data were detected in the cohort. Overall, 3.38% (487/14,406) of patients developed UC-PSC. During a mean follow-up duration of approximately 5.92 years, the incidence of PSC in patients with UC was 185 per 100,000 person-years. The UC-PSC group showed statistically more frequent healthcare use (hospitalization and emergency department visits: HRs, 5.986 and 9.302, respectively; P < .001), higher immunomodulator and biologic use (azathioprine, infliximab, and adalimumab: HRs, 2.061, 3.457, and 3.170, respectively; P < .001), and higher surgery rate (operation for intestinal obstruction, and colectomy: HRs, 9.728 and 2.940, respectively; P < .001) than did the UC-alone group. The UC-PSC group also showed significantly higher colorectal cancer and biliary tract cancer (HRs, 2.799 and 36.343, respectively; P < .001) and mortality (HR, 4.257) rates than did the UC-alone group.

CONCLUSION

Patients with UC-PSC have higher risks of colorectal cancer, biliary tract cancer, and death than do patients with UC-alone. Although considered a rare disease, managing this complex and costly disease requires recognition of the impact of increased burden on healthcare services.

Colitis ameliorates cholestatic liver disease via suppression of bile acid synthesis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the biliary tree. The majority of PSC patients suffer from concomitant inflammatory bowel disease (IBD), which has been suggested to promote disease development and progression. However, the molecular mechanisms by which intestinal inflammation may aggravate cholestatic liver disease remain incompletely understood. Here, we employ an IBD-PSC mouse model to investigate the impact of colitis on bile acid metabolism and cholestatic liver injury. Unexpectedly, intestinal inflammation and barrier impairment improve acute cholestatic liver injury and result in reduced liver fibrosis in a chronic colitis model. This phenotype is independent of colitis-induced alterations of microbial bile acid metabolism but mediated via hepatocellular NF-κB activation by lipopolysaccharide (LPS), which suppresses bile acid metabolism in-vitro and in-vivo. This study identifies a colitis-triggered protective circuit suppressing cholestatic liver disease and encourages multi-organ treatment strategies for PSC.

Colectomy in patients with ulcerative colitis is not associated to future diagnosis of primary sclerosing cholangitis

BACKGROUND

Primary Sclerosing Cholangitis (PSC) is a hepatobiliary disease closely related to ulcerative colitis (UC). In PSC patients, colectomy has been linked to improved prognosis, especially following liver transplantation. This suggests an involvement of the gut-liver axis in PSC etiology.

OBJECTIVE

We aimed to investigate the association between colectomy and the risk of future PSC in an epidemiological setting.

METHOD

Through nationwide registers, we identified all adults diagnosed with UC in Sweden 1990-2018 and retrieved information on PSC diagnosis and colectomy. Within the UC cohort (n = 61,993 patients), we matched 5577 patients with colectomy to 15,078 without colectomy. Matching criteria were sex, age at UC onset (±5 years), year of UC onset (±3 years), and proctitis at the time of colectomy. Incidence rates of PSC per 1000-person year were calculated, and the Cox proportional hazard regression model estimated hazard ratios (HRs) for PSC until 31 December 2019.

RESULTS

During the follow-up, 190 (3.4%) colectomized UC patients and 450 (3.0%) UC comparators developed PSC, yielding incidence rates of 2.6 and 2.4 per 1000 person-years (HR 1.07 [95% CI 0.90-1.28]). The cumulative incidence of colectomy decreased remarkably over calendar periods, but the cumulative incidence of PSC remained unchanged. The risk of developing PSC in colectomized versus comparators changed over time (HR 0.68 [95% CI; 0.48-0.96] in 1990-97 and HR 2.10 [95% CI; 1.37-3.24] in 2011-18).

CONCLUSIONS

In UC patients, colectomy was not associated with a decreased risk of subsequent PSC. The observed differences in the risk of PSC development over calendar periods are likely due to changes in PSC-diagnosis and UC-treatment.

Global burden of Liver Disease: 2023 Update

Liver disease accounts for 2 million deaths and is responsible for 4% of all deaths (1 out of every 25 deaths worldwide); approximately 2/3 of all liver related deaths occur in men. Deaths are largely attributable to complications of cirrhosis and hepatocellular carcinoma, with acute hepatitis accounting for a smaller proportion of deaths. The most common causes of cirrhosis worldwide are related to viral hepatitis, alcohol, and nonalcoholic fatty liver disease (NAFLD). Hepatotropic viruses are the etiological factor in most cases of acute hepatitis, but drug-induced liver injury increasingly accounts for a significant proportion of cases. This iteration of the global burden of liver disease is an update of the 2019 version and focuses mainly on areas where significant new information is available like alcohol-associated liver disease, NAFLD, viral hepatitis, and HCC. We also devote a separate section to the burden of liver disease in Africa, an area of the world typically neglected in such documents.

The microbiota and the gut-liver axis in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) offers unique opportunities to explore the gut-liver axis owing to the close association between liver disease and colonic inflammation. It is well established that the gut microbiota in people with PSC differs from that of healthy individuals, but details of the microbial factors that demarcate PSC from inflammatory bowel disease (IBD) without PSC are poorly understood. In this Review, we aim to provide an overview of the latest literature on the gut microbiome in PSC and PSC with IBD, critically examining hypotheses on how microorganisms could contribute to the pathogenesis of PSC. A particular emphasis will be put on pathogenic features of the gut microbiota that might explain the occurrence of bile duct inflammation and liver disease in the context of IBD, and we postulate the potential existence of a specific yet unknown factor related to the gut-liver axis as causative in PSC. Available data are scrutinized in the perspective of therapeutic approaches related to the gut-liver axis.

Gut immune cell trafficking: inter-organ communication and immune-mediated inflammation

Immune cell trafficking is a complex and tightly regulated process that is indispensable for the body's fight against pathogens. However, it is also increasingly acknowledged that dysregulation of cell trafficking contributes to the pathogenesis of immune-mediated inflammatory diseases (IMIDs) in gastroenterology and hepatology, such as inflammatory bowel disease and primary sclerosing cholangitis. Moreover, altered cell trafficking has also been implicated as a crucial step in the immunopathogenesis of other IMIDs, such as rheumatoid arthritis and multiple sclerosis. Over the past few years, a central role of the gut in mediating these disorders has progressively emerged, and the partly microbiota-driven imprinting of particular cell trafficking phenotypes in the intestine seems to be crucially involved. Therefore, this Review highlights achievements in understanding immune cell trafficking to, within and from the intestine and delineates its consequences for immune-mediated pathology along the gut-liver, gut-joint and gut-brain axes. We also discuss implications for current and future therapeutic approaches that specifically interfere with homing, retention, egress and recirculation of immune cells.

Primary sclerosing cholangitis-A long night's journey into day

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EASL Clinical Practice Guidelines on sclerosing cholangitis

Management of primary or secondary sclerosing cholangitis is challenging. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics including diagnostic methods, prognostic assessment, early detection of complications, optimal care pathways and therapeutic (pharmacological, endoscopic or surgical) options both in adults and children.

Epidemiology, Natural History, and Outcomes of Primary Sclerosing Cholangitis: A Systematic Review of Population-based Studies

BACKGROUND & AIMS

The aim of this study was to quantify the global epidemiology of primary sclerosing cholangitis (PSC), alongside the incidence of liver transplantation, cancer, and death, through robust systematic review of population-based data.

METHODS

We searched MEDLINE and EMBASE up to and including June 30, 2020 to identify population-based studies reporting the incidence and/or prevalence of PSC. Studies that did not report original data, or of exclusively pediatric-onset disease (diagnosis age <16 years) or exclusively PSC-associated with inflammatory bowel disease were excluded.

RESULTS

Of 4922 published studies, 17 fulfilled inclusion criteria; 16 documenting incidence and 14 prevalence. The highest reported incidence of PSC was reported in Northern Europe (Finland, 1.58 and Norway, 1.3 per-100,000 population, respectively) and North America (Minnesota, 1.47); with the lowest being observed across the Mediterranean Basin (Italy, 0.1). Prevalence ranged from 31.7 in Finland and 23.99 in Minnesota, to 1.33 in Singapore and 0.0 in Alaska. Of studies reporting temporal occurrence, an increase in disease incidence was observed across North America and Northern Europe (4 studies), alongside an increase in prevalence over time (4 studies). The incidence and risks for clinical outcomes were presented by 9 of the included studies. Median transplant-free survival ranged from 9.7 (United States) to 20.6 years (Netherlands), with standardized mortality ratios of 2.5 and 4.2 compared with the control population. The standardized incidence of cholangiocarcinoma ranged from 235 (Finland) to 398 (Netherlands).

CONCLUSIONS

Estimates of PSC incidence and prevalence vary, with most studies conducted in North America and Western Europe; the latter showing a steady increase in disease occurrence over time. Further research is needed to understand changes in disease epidemiology, including etiological drivers, the implications of rising case burden on health care policy, and better appreciation of PSC in the developing world.

AGPAT1 as a Novel Colonic Biomarker for Discriminating Between Ulcerative Colitis With and Without Primary Sclerosing Cholangitis

INTRODUCTION

Ulcerative colitis (UC) associated with primary sclerosing cholangitis (PSC-UC) is considered a unique inflammatory bowel disease (IBD) entity. PSC diagnosis in an IBD individual entails a significantly higher risk of gastrointestinal cancer; however, biomarkers for identifying patients with UC at risk for PSC are lacking. We, therefore, performed a thorough PSC-UC biomarker study, starting from archived colonic tissue.

METHODS

Proteins were extracted out of formalin-fixed paraffin-embedded proximal colon samples from PSC-UC (n = 9), UC (n = 7), and healthy controls (n = 7). Patients with IBD were in clinical and histological remission, and all patients with UC had a history of pancolitis. Samples were processed by the multienzyme digestion FASP and subsequently analyzed by liquid chromatography-tandem mass spectrometry. Candidate proteins were replicated in an independent cohort (n: PSC-UC = 16 and UC = 21) and further validated by immunohistochemistry.

RESULTS

In the discovery step, 7,279 unique proteins were detected. The top 5 most differentiating proteins (PSC-UC vs UC) based on linear regression analysis were selected for replication. Of these, 1-acetylglycerol-3-phosphate O-acyltransferase 1 (AGPAT1) was verified as higher in PSC-UC than UC (P = 0.009) in the replication cohort. A difference on the group level was also confirmed by immunohistochemistry, showing more intense AGPAT1 staining in patients with PSC-UC compared with UC.

DISCUSSION

We present AGPAT1 as a potential colonic biomarker for differentiating PSC-UC from UC. Our findings have possible implication for future PSC-IBD diagnostics and surveillance.

Small duct primary sclerosing cholangitis: A discrete variant or a bridge to large duct disease, a practical review

The natural history, associations with inflammatory bowel disease (IBD), and long-term outcomes of large duct primary sclerosing cholangitis (ldPSC) have been well documented. Small duct primary sclerosing cholangitis (sdPSC) is a much less common and relatively more benign variant. The natural history of sdPSC has been difficult to characterize given the limited number of studies in the literature especially with regards to the subset of patients who progress to large duct involvement. It has been unclear whether sdPSC represented a subset of ldPSC, an earlier staging of ldPSC, or a completely separate and distinct entity of its own. Strong associations between sdPSC and IBD have been established with suspicion that concurrent sdPSC-IBD may be a key prognostic factor in determining which patients are at risk of progression to ldPSC. Little is known regarding the discrete circumstances that predisposes some patients with sdPSC to progress to ldPSC. It has been suspected that progression to large biliary duct involvement subjects this subset of patients to potentially developing life-threatening complications. Here the authors conducted a thorough review of the published sdPSC literature using Pubmed searches and cross-referencing to compile all accessible studies regarding cohorts of sdPSC patients in order better characterize the subset of sdPSC patients who progress to ldPSC and the associated outcomes.

Choosing the right biologic for complications of inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition that involves the intestinal tract, and can also present with extra-intestinal manifestations (EIM). Choosing the right treatment for IBD is often nuanced and decisions can become even more complicated when a patient presents with or develops a complication of the disease.

AREAS COVERED

We aimed to provide an overview of the most common complications of IBD, specifically intestinal and EIM, and summarize the data regarding biologic therapy for treatment of these conditions. A comprehensive literature review was performed using PubMed and Medline databases to identify studies published in the English language relevant to the broad scope of this review.

EXPERT OPINION

There are still significant gaps in our understanding of the pathophysiology of IBD and its treatment, especially in regards to complications of the disease. As novel therapies continue to emerge for treatment of IBD, we feel concurrent examination of their impact on intestinal complications and EIM of IBD is important and should be a priority of future research.

Risk of hepato-pancreato-biliary cancer is increased by primary sclerosing cholangitis in patients with inflammatory bowel disease: A population-based cohort study

BACKGROUND

There is continued uncertainty regarding the risks of hepato-pancreato-biliary cancers in patients with inflammatory bowel disease (IBD) with or without concomitant primary sclerosing cholangitis (PSC).

OBJECTIVE

To give updated estimates on risk of hepato-pancreato-biliary cancers in patients with IBD, including pancreatic cancer, hepatocellular carcinoma, gall bladder cancer, and intra - and extrahepatic cholangiocarcinoma.

METHODS

In a population-based cohort study, we included all patients diagnosed with IBD in Norway and Sweden from 1987 to 2016. The cohort comprised of 141,960 patients, identified through hospital databases and the National Patient Register. Participants were followed through linkage to national cancer, cause of death, and population registries. We calculated absolute risk and standardized incidence ratios (SIRs) of hepato-pancreato-biliary cancers by PSC and other clinical characteristics.

RESULTS

Of the 141,960 IBD patients, 3.2% were diagnosed with PSC. During a median follow-up of 10.0 years, we identified 443 biliary tract cancers (SIR 5.2, 95% confidence interval [CI] 4.8-5.7), 161 hepatocellular carcinomas (SIR 2.4, 95% CI 2.0-2.7) and 282 pancreatic cancers (SIR 1.3, 95% CI 1.2-1.5). The relative risks were considerably higher in PSC-IBD patients, with SIR of 140 (95% CI 123-159) for biliary tract, 38.6 (95% CI 29.2-50.0) for hepatocellular, and 9.0 (95% CI 6.3-12.6) for pancreatic cancer. The SIRs were still slightly increased in non-PSC-IBD patients, compared to the general population. For biliary tract cancer, the cumulative probability at 25 years was 15.6% in PSC-IBD patients, and 0.4% in non-PSC-IBD patients.

CONCLUSIONS

The dramatically increased risks of hepato-pancreato-biliary cancers in PSC-IBD patients support periodic surveillance for these malignancies. While much lower, the excess relative risks in non-PSC-IBD patients were not trivial compared to non-IBD related risk factors.

Hepatobiliary manifestations in inflammatory bowel disease: A practical approach

Inflammatory bowel diseases (IBD) are associated with various hepatobiliary disorders. They can occur at any moment in the course of the disease or associated with the treatment. The prevalence of liver dysfunction can reach up to 50% in different studies. Nonalcoholic fatty liver disease is considered the most common hepatobiliary complication in IBD, while primary sclerosing cholangitis is the most specific. Management of hepatic manifestations in IBD involves a multidisciplinary approach that includes a high index of suspicion and joint management with hepatologists. The medical confrontation with abnormal liver tests must include an exhaustive study to determine if these patterns can be related to IBD, associated diseases or to the therapies used.

PSC associated inflammatory bowel disease: a distinct entity

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a rare, chronic, and progressive cholestatic disease involving intra- and/or extrahepatic bile ducts. PSC in many patients results in end-stage liver diseases. Nearly 60% of the PSC patients suffer from concomitant inflammatory bowel diseases (IBDs). Classically, IBDs are divided into two principle types: Crohn's disease (CD) and ulcerative colitis (UC). However, with growing knowledge, PSC-associated IBD (PSC-IBD) seems to be a rather distinct entity with specific genetics, clinical, and microbiota characteristics.

AREAS COVERED

In this article, we aim to review the unique characteristics of PSC-IBD from clinical, genetic, and microbiota point of view.

EXPERT OPINION

PSC-IBD's unique characteristics contribute to the notion that it could be a distinct entity. Acknowledgment of PSC-IBD as a novel entity necessitates designing new clinical guidelines for diagnosis and developing novel therapies.

Diagnosis of Primary Sclerosing Cholangitis Beyond Childhood is Associated with Worse Outcomes

BACKGROUND

The elucidation of differences between adult and pediatric-onset primary sclerosing cholangitis (PSC) may inform clinical decision making, and whether results of adult PSC clinical trials can be extrapolated to pediatric subjects.

METHODS

A single-center retrospective analysis of PSC subjects diagnosed during the epoch 2000-13 was conducted. Demographic, clinical, and laboratory data were compared between PSC subjects diagnosed between 0-18 (pediatric) and 19+ (adult) years of age. An adverse outcome was defined as PSC-related death, liver transplant, or malignancy. Survival without any of these was defined as event-free survival.

RESULTS

Analyses of 28 pediatric-diagnosed and 59 adult-diagnosed subjects revealed that incidence of early portal hypertension (PHT; P = 0.2), laboratory parameters of liver disease severity, and fibrosis grade at diagnosis were comparable between adult and pediatric PSC subjects. Adult-diagnosed PSC subjects had higher incidences of adverse outcomes compared to pediatric-diagnosed PSC subjects (P = 0.02). The age group 0-18 years (n = 30) had significantly better event-free survival compared to the age group more than 40 years (n = 25; P = 0.03). The prevalence of PHT in adult PSC subjects was 2.6 that of pediatric PSC subjects. PHT adversely affected outcomes in both adult (P < 0.001) and pediatric (P = 0.01) subjects. Adult PSC subjects were more likely to develop biliary complications (BCs; P = 0.001), ascites (P = 0.004), and variceal bleed (P = 0.03). Adult PSC subjects were more likely to have extra-hepatic co-morbidities (P < 0.001). Adult subjects had a longer follow-up duration compared to pediatric subjects (P = 0.06).

CONCLUSION

Despite having a comparable clinical, laboratory, and histologic biomarkers of liver disease severity at the time of diagnosis, adult PSC subjects had a worse outcome compared to pediatric PSC subjects. Possible reasons for this finding include higher incidence of PHT, BCs, extra-hepatic co-morbidities, and longer duration of follow-up.

Prevalence of Primary Sclerosing Cholangitis in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Although the association between inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) is well recognized, uncertainties remain about the magnitude of this problem. We conducted a systematic review and meta-analysis assessing prevalence of PSC in IBD to investigate whether type of IBD, how presence of PSC was defined, sex, disease extent or location, time period, or geographic location influenced prevalence.

METHODS

Medline, Embase, and Embase Classic were searched (from inception to April 10, 2021) to identify observational studies recruiting ≥50 adult patients with IBD and reporting prevalence of PSC. Data were extracted, and pooled prevalence, odds ratios (ORs), and 95% confidence intervals (CIs) calculated.

RESULTS

Of 1204 citations, 64 studies were eligible, containing 776,700 patients. Overall, pooled prevalence of PSC in IBD was 2.16%; it was highest in South America and lowest in Southeast Asia. Pooled prevalences in patients with ulcerative colitis (UC), Crohn's disease (CD), and IBD-unclassified were 2.47%, 0.96%, and 5.01%, respectively. Pooled prevalence was significantly higher in UC versus CD (OR 1.69, 95% CI 1.24-2.29). In subgroup analyses according to method used to define presence of PSC, the highest prevalence was 2.88% in studies performing both liver biochemistry and endoscopic retrograde/magnetic resonance cholangiopancreatography and the lowest was 1.79% in studies using a clinical diagnosis. Prevalence was generally higher in men, patients with more extensive, compared with left-side, UC or ileocolonic or colonic, compared with ileal, CD.

CONCLUSIONS

Our findings provide the first pooled estimates of the burden of PSC in IBD, as well as potential risk factors, which may be important in establishing a prompt diagnosis and initiating appropriate surveillance for relevant gastrointestinal malignancies.

Liver involvement in inflammatory bowel disease: What should the clinician know?

Inflammatory bowel disease (IBD) may show a wide range of extraintestinal manifestations. In this context, liver involvement is a focal point for both an adequate management of the disease and its prognosis, due to possible serious comorbidity. The association between IBD and primary sclerosing cholangitis is the most known example. This association is relevant because it implies an increased risk of both colorectal cancer and cholangiocarcinoma. Additionally, drugs such as thiopurines or biologic agents can cause drug-induced liver damage; therefore, this event should be considered when planning IBD treatment. Additionally, particular consideration should be given to the evidence that IBD patients may have concomitant chronic viral hepatitis, such as hepatitis B and hepatitis C. Chronic immunosuppressive regimens may cause a hepatitis flare or reactivation of a healthy carrier state, therefore careful monitoring of these patients is necessary. Finally, the spread of obesity has involved even IBD patients, thus increasing the risk of non-alcoholic fatty liver disease, which has already proven to be more common in IBD patients than in the non-IBD population. This phenomenon is considered an emerging issue, as it will become the leading cause of liver cirrhosis.

Clinical Features and Outcomes of Primary Sclerosing Cholangitis in the Highly Admixed Brazilian Population

BACKGROUND

Primary sclerosing cholangitis (PSC) is associated with a broad phenotypic spectrum in different populations from diverse ethnic and racial backgrounds. This study aimed to describe the clinical characteristics and outcomes of PSC in a multicenter cohort of patients from Brazil.

METHODS

Data from the Brazilian Cholestasis Study Group were retrospectively reviewed to assess demographic information and clinical characteristics of PSC, as well as the outcomes, such as transplantation-free survival.

RESULTS

This cohort included 210 patients. After excluding 33 (15.7%) patients with PSC and overlap syndrome of autoimmune hepatitis, 177 (97 males, median age 33 (21-42) years) with clear-cut PSC were eligible for this study. Most of the patients (n = 139, 78.5%) were symptomatic, and 104 (58.7%) had advanced PSC at the time of diagnosis. Concurrent inflammatory bowel disease was observed in 78 (58.6%) of the investigated patients (n = 133), and most of them had ulcerative colitis (n = 61, 78.2%). The 1- and 5-year survival free of liver transplantation or death were 92.3 ± 2.1% and 66.9 ± 4.2%, respectively, and baseline advanced PSC, pruritus, and elevated bilirubin levels were independent risk factors for the composite adverse outcome. Females were significantly older and had lower bilirubin levels than males at baseline, but survival was not associated with sex. Approximately 12.4% (n = 22) of patients with PSC died, and 32.8% (n = 58) underwent liver transplantation at a median follow-up time of 5.3 and 3.2 years.

CONCLUSION

Multiethnic Brazilian PSC patients exhibited a less pronounced male predominance and a lower frequency of inflammatory bowel disease than Caucasians. Adverse outcomes were more frequent, probably due to advanced disease at baseline.

Hepatobiliary phenotype of individuals with chronic intestinal disorders

Despite the known functional relationship between the gut and the liver, the clinical consequences of this circuit remain unclear. We assessed the hepatobiliary phenotype of cohorts with celiac disease (CeD), Crohn´s disease (CD) and ulcerative colitis (UC). Baseline liver function tests and the frequency of hepatobiliary diseases were analyzed in 2377 CeD, 1738 CD, 3684 UC subjects and 488,941 controls from the population-based UK Biobank cohort. In this cohort study associations were adjusted for age, sex, BMI, diabetes, and alcohol consumption. Compared to controls, cohorts with CeD, but not CD/UC displayed higher AST/ALT values. Subjects with CD/UC but not CeD had increased GGT levels. Elevated ALP and cholelithiasis were significantly more common in all intestinal disorders. Non-alcoholic steatohepatitis and hepatocellular carcinoma (HCC) were enriched in CeD and CD (NASH: taOR = 4.9 [2.2-11.0] in CeD, aOR = 4.2 [1.7-10.3] in CD, HCC: aOR = 4.8 [1.8-13.0] in CeD, aOR = 5.9 [2.2-16.1] in CD), while cholangitis was more common in the CD/UC cohorts (aOR = 11.7 [9.1-15.0] in UC, aOR = 3.5 [1.8-6.8] in CD). Chronic hepatitis, autoimmune hepatitis (AIH) and cirrhosis were more prevalent in all intestinal disorders. In UC/CD, a history of intestinal surgery was associated with elevated liver enzymes and increased occurrence of gallstones (UC: aOR = 2.9 [2.1-4.1], CD: 1.7 [1.2-2.3]). Our data demonstrate that different intestinal disorders predispose to distinct hepatobiliary phenotypes. An increased occurrence of liver cirrhosis, NASH, AIH and HCC and the impact of surgery warrant further exploration.

Global incidence, prevalence and features of primary sclerosing cholangitis: A systematic review and meta-analysis

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is an idiopathic, cholestatic liver disease with a diverse range of clinical manifestations. Inter-regional data on PSC are variable, but its global geoepidemiology has not been well-studied. We aimed to examine the worldwide incidence, prevalence and features of PSC and PSC-inflammatory bowel disease (PSC-IBD).

METHODS

A systematic search of multiple databases was conducted to identify all original, full-text studies until December 2020 with data regarding the incidence rate (IR) and/or prevalence of PSC. Outcomes were PSC IR, prevalence, features and IBD concurrence. Additionally, a meta-analysis of PSC IR was performed. The study was registered in PROSPERO (CRD42021224550).

RESULTS

Of the 1003 studies identified, 17 studies spanning three continents were included. PSC IR was 0.60 per 100 000 person-years (PY) (95% confidence interval: 0.37-0.88 per 100 000 PY). In pooled subgroup analysis for studies conducted in Europe and North America, PSC IR was 0.62 and 0.53 per 100 000 PY, respectively. PSC prevalence ranged 0-31.7 per 100 000 persons, with notable inter-regional differences. Mean age at PSC diagnosis was bimodally distributed, with relative peaks at 15 and 35 years. Mean concurrence of IBD with PSC was 50%, with 76% having ulcerative colitis, 17% Crohn's disease and 8% indeterminate/unspecified IBD.

CONCLUSION

While considerable heterogeneity exists in the geoepidemiology of PSC, overall, the classical dogmata of male predilection, bimodal distribution of mean age and high PSC-IBD concurrence appear to hold true. Despite a seemingly stable IR over time, further studies are needed to better understand the geoepidemiology of PSC.

The characteristics of pediatric ulcerative colitis with primary sclerosing cholangitis: A single-center study in Taiwan

BACKGROUND

Primary sclerosing cholangitis (PSC) is often associated with ulcerative colitis (UC). We investigated the clinical characteristics of pediatric UC patients with and without PSC.

METHODS

We retrospectively recruited children with UC, with and without PSC, from 2006 to 2017 in a tertiary center in Taiwan. The clinical data of the patients, including clinical and endoscopic UC severity scores, medications, and laboratory parameters, were analyzed.

RESULTS

We recruited five children with PSC-UC (PSC-UC group), and 26 with UC alone (non-PSC UC group) in this retrospective analysis. Among the patients with PSC-UC, four (80%) were compatible with definite or probable autoimmune sclerosing cholangitis (ASC). The UC Endoscopic Index of Severity (5.00 vs. 9.00, P = 0.003) and Mayo score (4.00 vs. 8.00, P = 0.014) were significantly lower in the PSC-UC group than the non-PSC UC group. The prevalence of immunomodulator use was significantly higher in the PSC-UC than the non-PSC UC group (100% vs. 42.3%, P = 0.043), but there was no difference regarding steroids, mesalamine, or biologics. At the end of the study, significantly fewer patients were steroid-free in the PSC-UC than the non-PSC UC group (20.0% vs. 84.6%, P = 0.010).

CONCLUSIONS

Pediatric patients with PSC-UC had less severe colitis than those with UC alone in terms of the clinical activity index and endoscopic severity index, but they were more likely to need an immunomodulator and less likely to be steroid-free in the long term, for the control of liver disease.

Recurrent Primary Sclerosing Cholangitis: Current Understanding, Management, and Future Directions

Patients with primary sclerosing cholangitis (PSC) constitute 5 to 15% of patients listed for liver transplantation worldwide. Although post-transplant outcomes are favorable, recurrent PSC (rPSC) occurs in an important subset of patients, with higher prevalence rates reported with increasing time from transplant. Given its association with poor graft outcomes and risk of retransplant, effort has been made to understand rPSC, its pathophysiology, and risk factors. This review covers these facets of rPSC and focuses on implicated risk factors including pretransplant recipient characteristics, inflammatory bowel-disease-related factors, and donor-specific and transplant-specific factors. Confirming a diagnosis of rPSC requires thoughtful consideration of alternative etiologies so as to ensure confidence in diagnosis, management, subsequent risk assessment, and counseling for patients. Unfortunately, no cure exists for rPSC; however, future large-scale efforts are underway to better characterize the natural history of rPSC and its associated risk factors with hopes of identifying potential key targets for novel therapies.

The role of natural killer cells in liver inflammation

The liver is an important immunological site that can promote immune tolerance or activation. Natural killer (NK) cells are a major immune subset within the liver, and therefore understanding their role in liver homeostasis and inflammation is crucial. Due to their cytotoxic function, NK cells are important in the immune response against hepatotropic viral infections but are also involved in the inflammatory processes of autoimmune liver diseases and fatty liver disease. Whether NK cells primarily promote pro-inflammatory or tolerogenic responses is not known for many liver diseases. Understanding the involvement of NK cells in liver inflammation will be crucial in effective treatment and future immunotherapeutic targeting of NK cells in these disease settings. Here, we explore the role that NK cells play in inflammation of the liver in the context of viral infection, autoimmunity and fatty liver disease.