Improving predictive accuracy in primary biliary cholangitis: A new genetic risk score

BACKGROUND AND AIMS

Genetic variants influence primary biliary cholangitis (PBC) risk. We established and tested an accurate polygenic risk score (PRS) using these variants.

METHODS

Data from two Italian cohorts (OldIT 444 cases, 901 controls; NewIT 255 cases, 579 controls) were analysed. The latest international genome-wide meta-analysis provided effect size estimates. The PRS, together with human leukocyte antigen (HLA) status and sex, was included in an integrated risk model.

RESULTS

Starting from 46 non-HLA genes, 22 variants were selected. PBC patients in the OldIT cohort showed a higher risk score than controls: -.014 (interquartile range, IQR, -.023, .005) versus -.022 (IQR -.030, -.013) (p < 2.2 × 10-16). For genetic-based prediction, the area under the curve (AUC) was .72; adding sex increased the AUC to .82. Validation in the NewIT cohort confirmed the model's accuracy (.71 without sex, .81 with sex). Individuals in the top group, representing the highest 25%, had a PBC risk approximately 14 times higher than that of the reference group (lowest 25%; p < 10-6).

CONCLUSION

The combination of sex and a novel PRS accurately discriminated between PBC cases and controls. The model identified a subset of individuals at increased risk of PBC who might benefit from tailored monitoring.

Artificial Intelligence and liver: Opportunities and barriers

Artificial Intelligence (AI) has recently been shown as an excellent tool for the study of the liver; however, many obstacles still have to be overcome for the digitalization of real-world hepatology. The authors present an overview of the current state of the art on the use of innovative technologies in different areas (big data, translational hepatology, imaging, and transplant setting). In clinical practice, physicians must integrate a vast array of data modalities (medical history, clinical data, laboratory tests, imaging, and pathology slides) to achieve a diagnostic or therapeutic decision. Unfortunately, machine learning and deep learning are still far from really supporting clinicians in real life. In fact, the accuracy of any technological support has no value in medicine without the support of clinicians. To make better use of new technologies, it is essential to improve clinicians' knowledge about them. To this end, the authors propose that collaborative networks for multidisciplinary approaches will improve the rapid implementation of AI systems for developing disease-customized AI-powered clinical decision support tools. The authors also discuss ethical, educational, and legal challenges that must be overcome to build robust bridges and deploy potentially effective AI in real-world clinical settings.

Bacterascites confers poor patient prognosis beyond MELD prediction

Spontaneous bacterial peritonitis (SBP) is a well-recognized clinical entity with a poor prognosis. In comparison, the prevalence, microbiological flora, and prognostic significance of bacterascites (BA) (the presence of organism on culture but ascitic PMN <250 cells/mm³) is largely unknown. We, therefore, assessed the prognosis and predictors of outcome in patients with BA in comparison with those with SBP. Ascitic fluid cultures from consecutive patients with cirrhosis from 2008 to 2018 were reviewed retrospectively, and patients with SBP and BA were identified. Baseline demographic, laboratory, and microbiological data were collated and analyzed as prognostic indicators, and clinical outcomes were recorded. Patients were censored at the time of LT, death, or last follow-up. For this study 176 and 213 cases of SBP and BA, respectively, were identified and included. Patients with SBP had significantly higher Model for End-Stage Liver Disease (MELD) ( p =<0.01), peripheral blood WCC ( p < 0.01), and higher rates of Enterobacteriaceae ( p < 0.01) and multi-drug resistant pathogens ( p < 0.01). Survival at 1 and 3 months was lower in patients with SBP ( p < 0.01) when compared with BA but at 6 months and beyond, no significant difference remained. After the exclusion of deaths within 30 days of presentation, survival between SBP and BA was equivocal at all time points. Mortality was substantially higher across all MELD groupings for both SBP and BA when compared with the predicted mortality calculated by the MELD score alone. BA has a negative impact on patient survival above that predicted by the MELD score. It has similar impact to SBP on patient survival beyond 1 month suggesting it should be seen as a poor prognostic marker and prompt consideration of LT where appropriate. Further studies evaluating the role of secondary prophylaxis in this group are required.

A quantitative MRCP-derived score for medium-term outcome prediction in primary sclerosing cholangitis

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is the gold standard for diagnosis of patients with primary sclerosing cholangitis (PSC). The semi-quantitative MRCP-derived Anali scores proposed for risk stratification, have poor-to-moderate inter-reader agreement.

AIMS

To evaluate the prognostic performance of quantitative MRCP metrics in PSC.

METHODS

This is a retrospective study of PSC patients undergoing MRCP. Images were processed using MRCP+ software (Perspectum Ltd, Oxford) that provides quantitative biliary features, semi-automatically extracted by artificial intelligence-driven analysis of MRCP-3D images. The prognostic value of biliary features has been assessed for all hepato-biliary complications.

RESULTS

87 PSC patients have been included in the analysis. Median follow-up from MRCP to event/censoring of 30.9 months (Q1-Q3=13.6-46.6). An adverse outcome occurred in 27 (31.0%) patients. The number of biliary strictures (HR=1.05 per unit, 95%CI 1.02-1.08, p < 0.0001), spleen length (HR=1.16 per cm, 95%CI 1.01-1.34, p = 0.039), adjusted for height, age at MRCP, and time from diagnosis to MRCP predicted higher risk of hepatobiliary complications. These were incorporated into a the quantitative MRCP-derived PSC (qMRCP-PSC) score (C-statistic=0.80). After 3-fold cross-validation, qMRCP-PSC outperformed the Anali score in our cohort (C-statistic of 0.78 vs 0.64) and enabled the discrimination of survival of PSC patients (log-rank p < 0.0001).

CONCLUSIONS

The qMRCP-PSC score identified patients at higher risk of hepatobiliary complications and outperformed the available radiological scores. It represents a novel quantitative biomarker for disease monitoring and a potential surrogate endpoint for clinical trials.

Risk stratification in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic liver disorder commonly affecting young patients and associated with uncertain prognosis and elevated risk of end-stage liver disease and hepatobiliary cancer. Rate of progression in PSC is heterogeneous and accurately predicting the disease course is of paramount importance to clinical practice and interventional trial design. So far, efforts have brought to the development of models looking at short-to-middle-term outcome using composite models including clinical, laboratory, radiological and histological parameters with limited performance. In the era of whole genome sequencing and digital innovation, the time is ripe for the development of stratified medicine in PSC. Efforts should be directed toward developing well-phenotyped cohorts of patients with longitudinal follow-up across sustained periods of time, application of novel image-processing technology, and biomarker discovery using multiomics platforms.

Open challenges in the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its etiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimization of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outlined the clinical characteristics, etiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provided evidence underlying the evolution of diagnostic and clinical management protocols.

GWAS and autoimmunity: What have we learned and what next

Autoimmune diseases are common conditions characterized by loss of tolerance, female predominance and a remarkable heterogeneity among different populations. Most often they are polygenic and several genetic loci have been linked with the risk of developing autoimmune diseases. However, causal inference is difficult. When the genomic revolution began there were high hopes of translating fast genetic analyses to the bedside but this has proven to be challenging. Nonetheless, over the last decade, fine-mapping strategies have greatly improved; one of the most significant research lines focuses on the in vivo and ex vivo definition of the effect of genetic variants within the target tissues and within specific subpopulations of immune cells that are involved in the disease pathogenesis. This strategy also includes the longitudinal tracking of a large number of immunophenotypes in many individuals to build a large reference atlas for variant characterization. In this review, we discuss the results obtained by GWAS in autoimmune diseases and review recent advances in fine mapping strategies. More importantly, we discuss gaps and future directions.

Artificial intelligence for precision medicine in autoimmune liver disease

Autoimmune liver diseases (AiLDs) are rare autoimmune conditions of the liver and the biliary tree with unknown etiology and limited treatment options. AiLDs are inherently characterized by a high degree of complexity, which poses great challenges in understanding their etiopathogenesis, developing novel biomarkers and risk-stratification tools, and, eventually, generating new drugs. Artificial intelligence (AI) is considered one of the best candidates to support researchers and clinicians in making sense of biological complexity. In this review, we offer a primer on AI and machine learning for clinicians, and discuss recent available literature on its applications in medicine and more specifically how it can help to tackle major unmet needs in AiLDs.

Genetics of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a rare disease of the liver characterized by an autoimmune attack on the small bile ducts. PBC is a complex trait, meaning that a large list of genetic factors interacts with environmental agents to determine its onset. Genome-wide association studies have had a huge impact in fostering research in PBC, but many steps need still to be done compared with other autoimmune diseases of similar prevalence. This review presents the state-of-the-art regarding the genetic architecture of PBC and provides some thoughtful reflections about possible future lines of research, which can be helpful to fill the missing heritability gap in PBC.

Predictors of serious adverse events and non-response in cirrhotic patients with primary biliary cholangitis treated with obeticholic acid

BACKGROUND & AIMS

Obeticholic acid (OCA) has recently been restricted in patients with primary biliary cholangitis (PBC) with "advanced cirrhosis" because of its narrow therapeutic index. We aimed to better define the predicting factors of hepatic serious adverse events (SAEs) and non-response in cirrhotic patients undergoing OCA therapy.

METHODS

Safety and efficacy of treatment were evaluated in a cohort of consecutive PBC cirrhotic patients started with OCA. OCA response was evaluated according to the Poise criteria. Risk factors for hepatic SAEs and non-response were reported as risk ratios (RR) with 95% confidence intervals (CIs).

RESULTS

One hundred PBC cirrhotics were included, 97 Child-Pugh class A and 3 class B. Thirty-one had oesophageal varices and 5 had a history of ascites. Thirty-three per cent and 32% of patients achieved a biochemical response at 6 and 12 months respectively. Male sex (adjusted-RR 1.75, 95%CI 1.42-2.12), INR (1.37, 1.00-1.87), Child-Pugh score (1.79, 1.28-2.50), MELD (1.17, 1.04-1.30) and bilirubin (1.83, 1.11-3.01) were independently associated with non-response to OCA. Twenty-two patients discontinued OCA within 12 months: 10 for pruritus, 9 for hepatic SAEs (5 for jaundice and/or ascitic decompensation; 4 for upper digestive bleeding). INR (adjusted-RR 1.91, 95%CI 1.10-3.36), lower albumin levels (0.18, 0.06-0.51), Child-Pugh score (2.43, 1.50-4.04), history of ascites (3.5, 1.85-6.5) and bilirubin (1.30, 1.05-1.56), were associated with hepatic SAEs. A total bilirubin≥1.4 mg/dl at baseline was the most accurate biochemical predictor of hepatic SAEs under OCA.

CONCLUSIONS

An accurate baseline assessment is crucial to select cirrhotic patients who can benefit from OCA. Although OCA is effective in one third of cirrhotics, bilirubin level ≥1.4 mg/dl should discourage from its use.

SARS-CoV-2 vaccination and risk of severe COVID-19 outcomes in patients with autoimmune hepatitis

Background

Data regarding outcome of Coronavirus disease 2019 (COVID-19) in vaccinated patients with autoimmune hepatitis (AIH) are lacking. We evaluated the outcome of COVID-19 in AIH patients who received at least one dose of Pfizer- BioNTech (BNT162b2), Moderna (mRNA-1273) or AstraZeneca (ChAdOx1-S) vaccine.

Patients and methods

We performed a retrospective study on AIH patients with COVID-19. The outcomes of AIH patients who had acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection after at least one dose of COVID-19 vaccine were compared to unvaccinated patients with AIH. COVID-19 outcome was classified according to clinical state during the disease course as: (i) no hospitalization, (ii) hospitalization without oxygen supplementation, (iii) hospitalization with oxygen supplementation by nasal cannula or mask, (iv) intensive care unit (ICU) admission with non-invasive mechanical ventilation, (v) ICU admission with invasive mechanical ventilation or (vi) death, and data was analyzed using ordinal logistic regression.

Results

We included 413 (258 unvaccinated and 155 vaccinated) patients (81%, female) with a median age of 52 (range: 17–85) years at COVID-19 diagnosis. The rates of hospitalization were (36.4% vs. 14.2%), need for any supplemental oxygen (29.5% vs. 9%) and mortality (7% vs. 0.6%) in unvaccinated and vaccinated AIH patients with COVID-19. Having received at least one dose of SARS-CoV-2 vaccine was associated with a significantly lower risk of worse COVID-19 severity, after adjusting for age, sex, comorbidities and presence of cirrhosis (adjusted odds ratio [aOR] 0.18, 95% confidence interval [CI], 0.10–0.31). Overall, vaccination against SARS-CoV-2 was associated with a significantly lower risk of mortality from COVID-19 (aOR 0.20, 95% CI 0.11–0.35).

Conclusions

SARS-CoV-2 vaccination significantly reduced the risk of COVID-19 severity and mortality in patients with AIH.

New insights on the role of human leukocyte antigen complex in primary biliary cholangitis

Primary Biliary Cholangitis (PBC) is a rare autoimmune cholangiopathy. Genetic studies have shown that the strongest statistical association with PBC has been mapped in the human leukocyte antigen (HLA) locus, a highly polymorphic area that mostly contribute to the genetic variance of the disease. Furthermore, PBC presents high variability throughout different population groups, which may explain the different geoepidemiology of the disease. A major role in defining HLA genetic contribution has been given by genome-wide association studies (GWAS) studies; more recently, new technologies have been developed to allow a deeper understanding. The study of the altered peptides transcribed by genetic alterations also allowed the development of novel therapeutic strategies in the context of immunotolerance. This review summarizes what is known about the immunogenetics of PBC with a focus on the HLA locus, the different distribution of HLA alleles worldwide, and how HLA modifications are associated with the pathogenesis of PBC. Novel therapeutic strategies are also outlined.

Role of ductular reaction and ductular-canalicular junctions in identifying severe primary biliary cholangitis

Background & Aims

Primary biliary cholangitis (PBC) is a chronic cholangiopathy characterised by immuno-mediated injury of interlobular bile ducts leading to intrahepatic cholestasis and progressive liver fibrosis. PBC histology is characterised by portal inflammation, progressive fibrosis, ductopenia, and the appearance of the so-called ductular reaction. The aim of the present study was to investigate the pathogenetic relevance of ductular reaction in PBC.

Methods

Liver biopsies were collected from naïve people with PBC (N = 87). Clinical-serological parameters were obtained at diagnosis and after 1 year of ursodeoxycholic acid (UDCA) treatment. Histological staging was performed on all slides according to multiple scoring systems and criteria for PBC. Liver samples were obtained from Mdr2 ^-/- mice treated with or without UDCA. Samples were processed for histology, immunohistochemistry, and immunofluorescence.

Results

Ductular reaction in people with PBC correlated with the disease stage and liver fibrosis, but not with disease activity; an extensive ductular reaction correlated with serum alkaline phosphatase levels at diagnosis, response to UDCA, and individuals' estimated survival, independently from other histological parameters, including disease stage. In people with PBC, reactive ductules were associated with the establishment of junctions with bile canaliculi and with fibrogenetic cell activation. Consistently, in a mouse model of intrahepatic cholestasis, UDCA treatment was effective in reducing ductular reaction and fibrosis and increasing ductular-canalicular junctions.

Conclusions

Extensive ductular reaction outlines a severe histologic phenotype in PBC and is associated with an inadequate therapy response and a worse estimated prognosis.

Lay summary

In people affected by primary biliary cholangitis (PBC), the histological appearance of extensive ductular reaction identifies individuals at risk of progressive fibrosis. Ductular reaction at diagnosis correlates with the lack of response to first-line therapy with ursodeoxycholic acid and serves to restore ductular-canalicular junctions in people with PBC. Assessing ductular reaction extension at diagnosis may add valuable information for clinicians.

Detailed stratified GWAS analysis for severe COVID-19 in four European populations

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

The Role of Epigenetics in Primary Biliary Cholangitis

Primary Biliary Cholangitis (PBC) is a rare autoimmune disease of the liver, affecting mostly females. There is evidence that epigenetic changes have a pathogenic role in PBC. Epigenetic modifications are related to methylation of CpG DNA islands, post-translational modifications of histone proteins, and non-coding RNAs. In PBC, there are data showing a dysregulation of all these levels, especially in immune cells. In addition, epigenetics seems to be involved in complex phenomena such as X monosomy or abnormalities in the process of X chromosome inactivation, which have been reported in PBC and appear to influence its sex imbalance and pathogenesis. We review here historical data on epigenetic modifications in PBC, present new data, and discuss possible links among X-chromosome abnormalities at a genetic and epigenetic level, PBC pathogenesis, and PBC sex imbalance.

Systematic review of response criteria and endpoints in autoimmune hepatitis by the International Autoimmune Hepatitis Group

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) has been well characterised and codified through the development of diagnostic criteria. These criteria have been adapted and simplified and are widely used in clinical practice. However, there is a need to update and precisely define the criteria for both treatment response and treatment.

METHODS

A systematic review was performed and a modified Delphi consensus process was used to identify and redefine the response criteria in autoimmune hepatitis.

RESULTS

The consensus process initiated by the International Autoimmune Hepatitis Group proposes that the term 'complete biochemical response' defined as 'normalization of serum transaminases and IgG below the upper limit of normal' be adopted to include a time point at 6 months after initiation of treatment. An insufficient response by 6 months was a failure to meet the above definition. Non-response was defined as '<50% decrease of serum transaminases within 4 weeks after initiation of treatment'. Remission is defined as liver histology with a Hepatitis Activity Index <4/18. Intolerance to treatment was agreed to stand for 'any adverse event possibly related to treatment leading to potential drug discontinuation'.

CONCLUSIONS

These definitions provide a simple and reproducible framework to define treatment response and non-response, irrespective of the therapeutic intervention. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable inter-study comparisons. Future prospective database studies are needed to validate these endpoints.

LAY SUMMARY

Consensus among international experts on response criteria and endpoints in autoimmune hepatitis is lacking. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable the comparison of results between clinical trials. Therefore, the International Autoimmune Hepatitis Group (IAIHG) herein presents a statement on 5 agreed response criteria and endpoints: complete biochemical response, insufficient response, non-response, remission, and intolerance to treatment, which can be used to guide future reporting.

X marks the spot in autoimmunity

INTRODUCTION

Autoimmune diseases mostly affect females. Besides hormones, several factors related to chromosome X have been called in action to explain this sex predominance.

AREAS COVERED

This paper provides an overview on the role of chromosome X (chrX) in explaining why females have higher susceptibility to autoimmunity. The work outlines some essential concepts regarding chrX inactivation, escape from chrX inactivation and the evolutionary history of chrX. In addition, we will discuss the concept of gene escape in immune cells, with examples related to specific X-linked genes and autoimmune diseases.

EXPERT OPINION

There is growing evidence that many genes present on chrX escape inactivation, and some of them have significant immune-mediated functions. In immune cells of female individuals the escape of these genes is not constant, but the knowledge of the mechanisms controlling this plasticity are not completely understood. Future studies aimed at the characterization of these modifications at single-cell resolution, together with conformational 3D studies of the inactive X chromosome, will hopefully help to fill this gap of knowledge.

Machine learning in primary biliary cholangitis: A novel approach for risk stratification

BACKGROUND & AIMS

Machine learning (ML) provides new approaches for prognostication through the identification of novel subgroups of patients. We explored whether ML could support disease sub-phenotyping and risk stratification in primary biliary cholangitis (PBC).

METHODS

ML was applied to an international dataset of PBC patients. The dataset was split into a derivation cohort (training set) and a validation cohort (validation set), and key clinical features were analysed. The outcome was a composite of liver-related death or liver transplantation. ML and standard survival analysis were performed.

RESULTS

The training set was composed of 11,819 subjects, while the validation set was composed of 1,069 subjects. ML identified four clusters of patients characterized by different phenotypes and long-term prognosis. Cluster 1 (n = 3566) included patients with excellent prognosis, whereas Cluster 2 (n = 3966) consisted of individuals at worse prognosis differing from Cluster 1 only for albumin levels around the limit of normal. Cluster 3 (n = 2379) included young patients with florid cholestasis and Cluster 4 (n = 1908) comprised advanced cases. Further sub-analyses on the dynamics of albumin within the normal range revealed that ursodeoxycholic acid-induced increase of albumin >1.2 x lower limit of normal (LLN) is associated with improved transplant-free survival.

CONCLUSIONS

Unsupervised ML identified four novel groups of PBC patients with different phenotypes and prognosis and highlighted subtle variations of albumin within the normal range. Therapy-induced increase of albumin >1.2 x LLN should be considered a treatment goal.

Effects of immunosuppressive drugs on COVID-19 severity in patients with autoimmune hepatitis

BACKGROUND

We investigated associations between baseline use of immunosuppressive drugs and severity of Coronavirus Disease 2019 (COVID-19) in autoimmune hepatitis (AIH).

PATIENTS AND METHODS

Data of AIH patients with laboratory confirmed COVID-19 were retrospectively collected from 15 countries. The outcomes of AIH patients who were on immunosuppression at the time of COVID-19 were compared to patients who were not on AIH medication. The clinical courses of COVID-19 were classified as (i)-no hospitalization, (ii)-hospitalization without oxygen supplementation, (iii)-hospitalization with oxygen supplementation by nasal cannula or mask, (iv)-intensive care unit (ICU) admission with non-invasive mechanical ventilation, (v)-ICU admission with invasive mechanical ventilation or (vi)-death and analysed using ordinal logistic regression.

RESULTS

We included 254 AIH patients (79.5%, female) with a median age of 50 (range, 17-85) years. At the onset of COVID-19, 234 patients (92.1%) were on treatment with glucocorticoids (n = 156), thiopurines (n = 151), mycophenolate mofetil (n = 22) or tacrolimus (n = 16), alone or in combinations. Overall, 94 (37%) patients were hospitalized and 18 (7.1%) patients died. Use of systemic glucocorticoids (adjusted odds ratio [aOR] 4.73, 95% CI 1.12-25.89) and thiopurines (aOR 4.78, 95% CI 1.33-23.50) for AIH was associated with worse COVID-19 severity, after adjusting for age-sex, comorbidities and presence of cirrhosis. Baseline treatment with mycophenolate mofetil (aOR 3.56, 95% CI 0.76-20.56) and tacrolimus (aOR 4.09, 95% CI 0.69-27.00) were also associated with more severe COVID-19 courses in a smaller subset of treated patients.

CONCLUSION

Baseline treatment with systemic glucocorticoids or thiopurines prior to the onset of COVID-19 was significantly associated with COVID-19 severity in patients with AIH.

MEDTEC Students against Coronavirus: Investigating the Role of Hemostatic Genes in the Predisposition to COVID-19 Severity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of the coronavirus disease 2019 (COVID-19) pandemic. Besides virus intrinsic characteristics, the host genetic makeup is predicted to account for the extreme clinical heterogeneity of the disease, which is characterized, among other manifestations, by a derangement of hemostasis associated with thromboembolic events. To date, large-scale studies confirmed that genetic predisposition plays a role in COVID-19 severity, pinpointing several susceptibility genes, often characterized by immunologic functions. With these premises, we performed an association study of common variants in 32 hemostatic genes with COVID-19 severity. We investigated 49,845 single-nucleotide polymorphism in a cohort of 332 Italian severe COVID-19 patients and 1668 controls from the general population. The study was conducted engaging a class of students attending the second year of the MEDTEC school (a six-year program, held in collaboration between Humanitas University and the Politecnico of Milan, allowing students to gain an MD in Medicine and a Bachelor’s Degree in Biomedical Engineering). Thanks to their willingness to participate in the fight against the pandemic, we evidenced several suggestive hits (p < 0.001), involving the PROC, MTHFR, MTR, ADAMTS13, and THBS2 genes (top signal in PROC: chr2:127192625:G:A, OR = 2.23, 95%CI = 1.50–3.34, p = 8.77 × 10⁻⁵). The top signals in PROC, MTHFR, MTR, ADAMTS13 were instrumental for the construction of a polygenic risk score, whose distribution was significantly different between cases and controls (p = 1.62 × 10⁻⁸ for difference in median levels). Finally, a meta-analysis performed using data from the Regeneron database confirmed the contribution of the MTHFR variant chr1:11753033:G:A to the predisposition to severe COVID-19 (pooled OR = 1.21, 95%CI = 1.09–1.33, p = 4.34 × 10⁻¹⁴ in the weighted analysis).

An international genome-wide meta-analysis of primary biliary cholangitis: Novel risk loci and candidate drugs

BACKGROUNDS & AIMS

Primary biliary cholangitis (PBC) is a chronic liver disease in which autoimmune destruction of the small intrahepatic bile ducts eventually leads to cirrhosis. Many patients have inadequate response to licensed medications, motivating the search for novel therapies. Previous genome-wide association studies (GWAS) and meta-analyses (GWMA) of PBC have identified numerous risk loci for this condition, providing insight into its aetiology. We undertook the largest GWMA of PBC to date, aiming to identify additional risk loci and prioritise candidate genes for in silico drug efficacy screening.

METHODS

We combined new and existing genotype data for 10,516 cases and 20,772 controls from 5 European and 2 East Asian cohorts.

RESULTS

We identified 56 genome-wide significant loci (20 novel) including 46 in European, 13 in Asian, and 41 in combined cohorts; and a 57th genome-wide significant locus (also novel) in conditional analysis of the European cohorts. Candidate genes at newly identified loci include FCRL3, INAVA, PRDM1, IRF7, CCR6, CD226, and IL12RB1, which each play key roles in immunity. Pathway analysis reiterated the likely importance of pattern recognition receptor and TNF signalling, JAK-STAT signalling, and differentiation of T helper (TH)1 and TH17 cells in the pathogenesis of this disease. Drug efficacy screening identified several medications predicted to be therapeutic in PBC, some of which are well-established in the treatment of other autoimmune disorders.

CONCLUSIONS

This study has identified additional risk loci for PBC, provided a hierarchy of agents that could be trialled in this condition, and emphasised the value of genetic and genomic approaches to drug discovery in complex disorders.

LAY SUMMARY

Primary biliary cholangitis (PBC) is a chronic liver disease that eventually leads to cirrhosis. In this study, we analysed genetic information from 10,516 people with PBC and 20,772 healthy individuals recruited in Canada, China, Italy, Japan, the UK, or the USA. We identified several genetic regions associated with PBC. Each of these regions contains several genes. For each region, we used diverse sources of evidence to help us choose the gene most likely to be involved in causing PBC. We used these 'candidate genes' to help us identify medications that are currently used for treatment of other conditions, which might also be useful for treatment of PBC.

Accuracy of Transient Elastography in Assessing Fibrosis at Diagnosis in Naïve Patients With Primary Biliary Cholangitis: A Dual Cut-Off Approach

BACKGROUND AND AIMS

Liver fibrosis holds a relevant prognostic meaning in primary biliary cholangitis (PBC). Noninvasive fibrosis evaluation using vibration-controlled transient elastography (VCTE) is routinely performed. However, there is limited evidence on its accuracy at diagnosis in PBC. We aimed to estimate the diagnostic accuracy of VCTE in assessing advanced fibrosis (AF) at disease presentation in PBC.

APPROACH AND RESULTS

We collected data from 167 consecutive treatment-naïve PBC patients who underwent liver biopsy (LB) at diagnosis at six Italian centers. VCTE examinations were completed within 12 weeks of LB. Biopsies were scored by two blinded expert pathologists, according to the Ludwig system. Diagnostic accuracy was estimated using the area under the receiver operating characteristic curves (AUROCs) for AF (Ludwig stage ≥III). Effects of biochemical and clinical parameters on liver stiffness measurement (LSM) were appraised. The derivation cohort consisted of 126 patients with valid LSM and LB; VCTE identified patients with AF with an AUROC of 0.89. LSM cutoffs ≤6.5 and >11.0 kPa enabled to exclude and confirm, respectively, AF (negative predictive value [NPV] = 0.94; positive predictive value [PPV] = 0.89; error rate = 5.6%). These values were externally validated in an independent cohort of 91 PBC patients (NPV = 0.93; PPV = 0.89; error rate = 8.6%). Multivariable analysis found that the only parameter affecting LSM was fibrosis stage. No association was found with BMI and liver biochemistry.

CONCLUSIONS

In a multicenter study of treatment-naïve PBC patients, we identified two cutoffs (LSM ≤6.5 and >11.0 kPa) able to discriminate at diagnosis the absence or presence, respectively, of AF in PBC patients, with external validation. In patients with LSM between these two cutoffs, VCTE is not reliable and liver biopsy should be evaluated for accurate disease staging. BMI and liver biochemistry did not affect LSMs.

Cost of illness of Primary Biliary Cholangitis - a population-based study

BACKGROUND

The economic burden of Primary Biliary Cholangitis (PBC) has not been investigated at population-level. Aim of this study was to estimate the cost of illness of PBC in Lombardy, Italy.

METHODS

Individuals with PBC were identified through ICD-9-CM code 571.6 and/or medical exemption code 008.571.6, from the Banca Dati Assistito of Lombardy. Only health services (outpatient, inpatient activities and drugs) related to PBC were considered to estimate direct medical costs in 2017.

RESULTS

We identified 970 adult patients (83.5% females) with a mean age of 61 years. Global annual costs were equal to € 913,763 (€ 942 per patient), with € 459,506 (50.3%, € 474 per patient) deriving from hospitalizations (mostly due to liver transplantation, 30.5%, and cirrhosis complications, 20.6%). Costs from outpatient activities were € 109,090 (11.9%, € 112 per patient).

CONCLUSIONS

This study provides an overview of the costs attributed to PBC care and management, mainly related to hospitalizations for cirrhosis complications, which is necessary for assuring cost-effective introduction of novel therapies. Additional studies focused on indirect cost, e.g. overall loss of productivity, are warranted.

Outcome of COVID-19 in Patients With Autoimmune Hepatitis: An International Multicenter Study

BACKGROUND AND AIMS

Data regarding outcome of COVID-19 in patients with autoimmune hepatitis (AIH) are lacking.

APPROACH AND RESULTS

We performed a retrospective study on patients with AIH and COVID-19 from 34 centers in Europe and the Americas. We analyzed factors associated with severe COVID-19 outcomes, defined as the need for mechanical ventilation, intensive care admission, and/or death. The outcomes of patients with AIH were compared to a propensity score-matched cohort of patients without AIH but with chronic liver diseases (CLD) and COVID-19. The frequency and clinical significance of new-onset liver injury (alanine aminotransferase > 2 × the upper limit of normal) during COVID-19 was also evaluated. We included 110 patients with AIH (80% female) with a median age of 49 (range, 18-85) years at COVID-19 diagnosis. New-onset liver injury was observed in 37.1% (33/89) of the patients. Use of antivirals was associated with liver injury (P = 0.041; OR, 3.36; 95% CI, 1.05-10.78), while continued immunosuppression during COVID-19 was associated with a lower rate of liver injury (P = 0.009; OR, 0.26; 95% CI, 0.09-0.71). The rates of severe COVID-19 (15.5% versus 20.2%, P = 0.231) and all-cause mortality (10% versus 11.5%, P = 0.852) were not different between AIH and non-AIH CLD. Cirrhosis was an independent predictor of severe COVID-19 in patients with AIH (P < 0.001; OR, 17.46; 95% CI, 4.22-72.13). Continuation of immunosuppression or presence of liver injury during COVID-19 was not associated with severe COVID-19.

CONCLUSIONS

This international, multicenter study reveals that patients with AIH were not at risk for worse outcomes with COVID-19 than other causes of CLD. Cirrhosis was the strongest predictor for severe COVID-19 in patients with AIH. Maintenance of immunosuppression during COVID-19 was not associated with increased risk for severe COVID-19 but did lower the risk for new-onset liver injury during COVID-19.

X Chromosome Contribution to the Genetic Architecture of Primary Biliary Cholangitis

BACKGROUND & AIMS

Genome-wide association studies in primary biliary cholangitis (PBC) have failed to find X chromosome (chrX) variants associated with the disease. Here, we specifically explore the chrX contribution to PBC, a sexually dimorphic complex autoimmune disease.

METHODS

We performed a chrX-wide association study, including genotype data from 5 genome-wide association studies (from Italy, United Kingdom, Canada, China, and Japan; 5244 case patients and 11,875 control individuals).

RESULTS

Single-marker association analyses found approximately 100 loci displaying P < 5 × 10-4, with the most significant being a signal within the OTUD5 gene (rs3027490; P = 4.80 × 10-6; odds ratio [OR], 1.39; 95% confidence interval [CI], 1.028-1.88; Japanese cohort). Although the transethnic meta-analysis evidenced only a suggestive signal (rs2239452, mapping within the PIM2 gene; OR, 1.17; 95% CI, 1.09-1.26; P = 9.93 × 10-8), the population-specific meta-analysis showed a genome-wide significant locus in East Asian individuals pointing to the same region (rs7059064, mapping within the GRIPAP1 gene; P = 6.2 × 10-9; OR, 1.33; 95% CI, 1.21-1.46). Indeed, rs7059064 tags a unique linkage disequilibrium block including 7 genes: TIMM17B, PQBP1, PIM2, SLC35A2, OTUD5, KCND1, and GRIPAP1, as well as a superenhancer (GH0XJ048933 within OTUD5) targeting all these genes. GH0XJ048933 is also predicted to target FOXP3, the main T-regulatory cell lineage specification factor. Consistently, OTUD5 and FOXP3 RNA levels were up-regulated in PBC case patients (1.75- and 1.64-fold, respectively).

CONCLUSIONS

This work represents the first comprehensive study, to our knowledge, of the chrX contribution to the genetics of an autoimmune liver disease and shows a novel PBC-related genome-wide significant locus.

Immune-Mediated Drug-Induced Liver Injury: Immunogenetics and Experimental Models

Drug-induced liver injury (DILI) is a challenging clinical event in medicine, particularly because of its ability to present with a variety of phenotypes including that of autoimmune hepatitis or other immune mediated liver injuries. Limited diagnostic and therapeutic tools are available, mostly because its pathogenesis has remained poorly understood for decades. The recent scientific and technological advancements in genomics and immunology are paving the way for a better understanding of the molecular aspects of DILI. This review provides an updated overview of the genetic predisposition and immunological mechanisms behind the pathogenesis of DILI and presents the state-of-the-art experimental models to study DILI at the pre-clinical level.

Multiple therapeutic targets in rare cholestatic liver diseases: Time to redefine treatment strategies

Primary biliary cholangitis and primary sclerosing cholangitis are rare diseases affecting the bile ducts and the liver. The limited knowledge of their pathogenesis leads to limited therapeutic options. Nevertheless, the landscape of novel therapies for these cholangiopathies is now rapidly changing, providing new treatment opportunities for patients and clinicians involved in their care. The aim of this review is to summarize the evidence of novel molecules under investigation for primary biliary cholangitis and primary sclerosing cholangitis and to discuss how they can potentially change current treatment paradigms.

Quality of life in patients with primary biliary cholangitis: A cross-geographical comparison

Background & aims

Several symptoms impair the quality of life (QoL) of patients with primary biliary cholangitis (PBC). They are reported to vary significantly in different countries. Aim of our study was to explore whether there is a geographical clustering that accounts for symptoms in PBC.

Methods

Data was analysed from four cohorts of PBC patients from the UK, Spain, Japan and Italy using the PBC-27 scale.

Results

Overall, 569 patients from four cohorts were identified, including 515 females (90.5%) with a mean age of 61 years. The analysis provided evidence for strict factorial invariance of the scale, a robust indicator of its validity for cross-cultural research. The mean of the fatigue domain of British patients was significantly greater than that of the Japanese (p ​< ​0.05), Italian (p ​< ​0.05), and Spanish patients (p ​< ​0.001). The mean of the cognitive domain after 54 years of age, was significantly greater in the British patients than in the Japanese (p ​< ​0.05) and Spanish patients (p ​< ​0.01). However, after 69 years of age, there were not significant differences between countries. The mean of the emotion domain after 54 years of age, was greater in the British that in the Spanish (p ​< ​0.01) and Italian patients (p ​< ​0.01).

Conclusions

Differences in the four countries concerning fatigue, cognitive and emotional dysfunction were found. The association of latitude and symptoms might provide new insights into the role of sun exposure, genetics and/or cultural component into disease phenotype in PBC.

Case Report: Hypomorphic Function and Somatic Reversion in DOCK8 Deficiency in One Patient With Two Novel Variants and Sclerosing Cholangitis

DOCK8 deficiency is a combined immunodeficiency due to biallelic variants in dedicator of cytokinesis 8 (DOCK8) gene. The disease has a wide clinical spectrum encompassing recurrent infections (candidiasis, viral and bacterial infections), virally driven malignancies and immune dysregulatory features, including autoimmune (cytopenia and vasculitis) as well as allergic disorders (eczema, asthma, and food allergy). Hypomorphic function and somatic reversion of DOCK8 has been reported to result in incomplete phenotype without IgE overproduction. Here we describe a case of DOCK8 deficiency in a 8-year-old Caucasian girl. The patient's disease was initially classified as autoimmune thrombocytopenia, which then evolved toward a combined immunodeficiency phenotype with recurrent infections, persistent EBV infection and lymphoproliferation. Two novel variants (one deletion and one premature stop codon) were characterized, resulting in markedly reduced, but not absent, DOCK8 expression. Somatic reversion of the DOCK8 deletion was identified in T cells. Hypomorphic function and somatic reversion were associated with restricted T cell repertoire, decreased STAT5 phosphorylation and impaired immune synapse functioning in T cells. Although the patient presented with incomplete phenotype (absence of markedly increase IgE and eosinophil count), sclerosing cholangitis was incidentally detected, thus indicating that hypomorphic function and somatic reversion of DOCK8 may delay disease progression but do not necessarily prevent from severe complications.

Risk stratification in primary sclerosing cholangitis

Primary Sclerosing Cholangitis (PSC) is a chronic liver disorder commonly affecting young patients and associated with uncertain prognosis and elevated risk of end-stage liver disease and hepatobiliary cancer. Rate of progression in PSC is heterogeneous and accurately predicting the disease course is of paramount importance to clinical practice and interventional trial design. So far, efforts have brought to the development of models looking at short-to-middle-term outcome using composite models including clinical, laboratory, radiological and histological parameters with limited performance. In the era of whole genome sequencing and digital innovation, the time is ripe for the development of stratified medicine in PSC. Efforts should be directed toward developing wellphenotyped cohorts of patients with longitudinal follow-up across sustained periods of time, application of novel image-processing technology, and biomarker discovery using multi-omics platforms.

Open challenges in the management of autoimmune hepatitis

Autoimmune Hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its aetiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimisation of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outline the clinical characteristics, aetiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provide evidence underlying the evolution of diagnostic and clinical management protocols.

Long-term impact of preventive UDCA therapy after transplantation for primary biliary cholangitis

BACKGROUND & AIMS

Recurrence of primary biliary cholangitis (PBC) after liver transplantation (LT) is frequent and can impair graft and patient survival. Ursodeoxycholic acid (UDCA) is the current standard therapy for PBC. We investigated the effect of preventive exposure to UDCA on the incidence and long-term consequences of PBC recurrence after LT.

METHODS

We performed a retrospective cohort study in 780 patients transplanted for PBC, between 1983-2017 in 16 centers (9 countries), and followed-up for a median of 11 years. Among them, 190 received preventive UDCA (10-15 mg/kg/day). The primary outcome was histological evidence of PBC recurrence. The secondary outcomes were graft loss, liver-related death, and all-cause death. The association between preventive UDCA and outcomes was quantified using multivariable-adjusted Cox and restricted mean survival time (RMST) models.

RESULTS

While recurrence of PBC significantly shortened graft and patient survival, preventive exposure to UDCA was associated with reduced risk of PBC recurrence (adjusted hazard ratio [aHR] 0.41; 95% CI 0.28-0.61; p <0.0001), graft loss (aHR 0.33; 95% CI 0.13-0.82; p <0.05), liver-related death (aHR 0.46; 95% CI 0.22-0.98; p <0.05), and all-cause death (aHR 0.69; 95% CI 0.49-0.96; p <0.05). On RMST analysis, preventive UDCA led to a survival gain of 2.26 years (95% CI 1.28-3.25) over a period of 20 years. Exposure to cyclosporine rather than tacrolimus had a complementary protective effect alongside preventive UDCA, reducing the cumulative incidence of PBC recurrence and all-cause death.

CONCLUSIONS

Preventive UDCA after LT for PBC is associated with a reduced risk of disease recurrence, graft loss, and death. A regimen combining cyclosporine and preventive UDCA is associated with the lowest risk of PBC recurrence and mortality.

LAY SUMMARY

Recurrence of primary biliary cholangitis after liver transplantation is frequent and can impair graft and patient survival. We performed the largest international study of transplanted patients with primary biliary cholangitis to date. Preventive administration of ursodeoxycholic acid after liver transplantation was associated with reduced risk of disease recurrence, graft loss, liver-related and all-cause mortality. A regimen combining cyclosporine and preventive ursodeoxycholic acid was associated with the best outcomes.

Coronavirus Disease 2019 in Autoimmune Hepatitis: A Lesson From Immunosuppressed Patients

Chronic immunosuppression is associated with increased and more severe viral infections. However, little is known about the association between immunosuppression and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Our aim was to describe the clinical course of patients with immunosuppressed autoimmune hepatitis (AIH) during coronavirus disease 2019 (COVID-19) infection in Italy. Our study is a case series of patients with AIH treated with immunosuppression, who tested positive for SARS-CoV-2 in March 2020 during the outbreak of COVID-19. Ten patients from seven different hospitals in Italy were diagnosed with COVID-19 during the outbreak of SARS-CoV-2 in March 2020. Seven subjects were female (70%), and age ranged from 27 to 73 years. Before the onset of SARS-CoV-2 infection, all patients were taking immunosuppressive therapy for AIH, and eight of them were on biochemical remission. Two other patients had recent acute onset of their AIH, and consequently started high-dose steroids, as per induction protocol. All patients had a respiratory syndrome and a positive nasal swab for SARS-CoV-2. Five patients developed a computed tomography-confirmed COVID-19 pneumonia. Six subjects received a combination of antiretroviral and antimalarial drugs. In seven patients, the dosage of immunosuppressive medication was changed. Liver enzymes were repeated during SARS-CoV-2 infection in all hospitalized cases; they remained within the normal range in all cases, and improved in the two acute cases treated with high-dose steroids. The clinical outcome was comparable to the reported cases occurring in non-immunosuppressed subjects. Conclusion: Patients under immunosuppressive therapy for AIH developing COVID-19 show a disease course presumptively similar to that reported in the non-immunosuppressed population. These data might aid in medical decisions when dealing with SARS-CoV-2 infection in immunocompromised patients.

Soluble CD163 and mannose receptor as markers of liver disease severity and prognosis in patients with primary biliary cholangitis

INTRODUCTION

In primary biliary cholangitis (PBC), macrophages are involved in liver inflammation and fibrosis. The macrophage activation markers, soluble (s)CD163 and mannose receptor (sMR) are associated with liver disease severity and prognosis in other chronic liver diseases. We aimed to investigate sCD163 and sMR in patients with PBC.

METHODS

We investigated PBC patients from the Italian PBC Study Group cohort and measured macrophage activation markers in serum at study enrolment. Patients were followed from enrolment until they experienced an event or were censored at their last visit. Events were defined as follows: (a) death from a liver-related cause; or (b) liver transplantation (LT) for PBC. We used Cox regression to investigate the association between sCD163 and sMR and long-term prognosis.

RESULTS

In total, 202 PBC patients were included. Median age was 62 years (interquartile range (IQR), 53-71) at enrolment and 93% were women. Median sCD163 was 3.43 mg/L (IQR 2.48-5.35) and median sMR was 0.35 mg/L (IQR 0.28-0.45). There was an increase in sCD163 and sMR with increasing alkaline phosphatase. Two hundred and one patients were followed for a median of 8.6 years, and sCD163 and sMR predicted long-term risk of liver-related death or LT in univariate analyses, while sCD163 was also associated with outcome after confounder adjusting (adjusted HR = 1.14, 95% CI 1.00-1.30). Finally, we showed an increase in the prediction accuracy of poor outcome by adding sCD163 to the UK-PBC risk score.

CONCLUSION

The macrophage activation markers sCD163 and sMR represent a non-invasive measure of PBC disease severity that provides useful long-term prognostic information.

New Therapeutic Targets in Autoimmune Cholangiopathies

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are autoimmune cholangiopathies characterized by limited treatment options. A more accurate understanding of the several pathways involved in these diseases has fostered the development of novel and promising targeted drugs. For PBC, the characterization of the role of farnesoid X receptor (FXR) and perixosome-proliferator activated receptor (PPAR) has paved the way to several clinical trials including different molecules with choleretic and antinflammatory action. Conversely, different pathogenetic models have been proposed in PSC such as the “leaky gut” hypothesis, a dysbiotic microbiota or a defect in mechanisms protecting against bile acid toxicity. Along these theories, new treatment approaches have been developed, ranging from drugs interfering with trafficking of lymphocytes from the gut to the liver, fecal microbiota transplantation or new biliary acids with possible immunomodulatory potential. Finally, for both diseases, antifibrotic agents are under investigation. In this review, we will illustrate current understanding of molecular mechanisms in PBC and PSC, focusing on actionable biological pathways for which novel treatments are being developed.

Novel biomarkers for primary biliary cholangitis to improve diagnosis and understand underlying regulatory mechanisms

BACKGROUND AND AIMS

Primary biliary cholangitis is an autoimmune biliary disease characterized by injury of bile ducts, eventually leading to cirrhosis and death. In most cases, anti-mitochondrial antibodies and persistently elevated serum alkaline phosphatase are the basis for the serological diagnosis. Anti-nuclear antibodies are also useful and may indicate a more aggressive diseases course. In patients in which anti-mitochondrial antibodies are not detected, an accurate diagnosis requires liver histology. This study aims at identifying specific biomarkers for the serological diagnosis of primary biliary cholangitis.

METHODS

Sera from patients affected by primary biliary cholangitis, primary sclerosing cholangitis, hepatitis C virus (with and without cryoglobulinemia), hepatocarcinoma and healthy donors were tested on a protein array representing 1658 human proteins. The most reactive autoantigens were confirmed by DELFIA analysis on expanded cohorts of the same mentioned serum classes, and on autoimmune hepatitis sera, using anti-PDC-E2 as reference biomarker.

RESULTS

Two autoantigens, SPATA31A3 and GARP, showed high reactivity with primary biliary cholangitis sera, containing or not anti-mitochondrial antibodies. Their combination with PDC-E2 allowed to discriminate primary biliary cholangitis from all tested control classes with high sensitivity and specificity. We found that GARP expression is upregulated upon exposure to biliary salts in human cholangiocytes, an event involving EGFR and insulin pathways. GARP expression was also detected in biliary duct cells of PBC patients.

CONCLUSIONS

This study highlighted SPATA31A3 and GARP as new biomarkers for primary biliary cholangitis and unravelled molecular stimuli underlying GARP expression in human cholangiocytes.

A National Hospital-Based Study of Hospitalized Patients With Primary Biliary Cholangitis

Epidemiological studies on primary biliary cholangitis (PBC) have been based primarily on tertiary referral case series. We aimed to estimate the incidence and prevalence and describe comorbidities in hospitalized patients with PBC in Italy using a national hospital-based data source. Data were extracted from the National Hospital Discharge Database, which includes all Italian individuals discharged from any hospital in the country. All adults diagnosed with biliary cirrhosis (International Classification of Diseases, Ninth Revision, Clinical Modification, 571.6) as the primary or secondary diagnosis from 2011 to 2015 were included. To determine whether a comorbidity was either more or less frequent in PBC patients compared with the general hospitalized Italian population, the standardized hospitalization ratio (SHR) was calculated. A total of 5,533 incident cases were identified from 2011 to 2015, 3,790 of whom were females (68.5%; female to male [F:M] ratio, 2.2:1). Prevalent cases were 9,664, of whom 7,209 were females (74.6%; F:M ratio, 2.9:1). The incident rate was 1.03 × 100,000 in males and 1.92 × 100,000 in females; prevalence was 1.89 × 100,000 in males and 4.75 × 100,000 in females. Extrahepatic autoimmune diseases, malignant neoplasms of liver and intrahepatic biliary ducts, and malignant neoplasms of gallbladder and extrahepatic bile ducts were found more frequently in PBC patients than in the general hospitalized population (SHR > 100), whereas cerebrovascular diseases and ischemic heart diseases were less frequent in PBC individuals (SHR < 100). Conclusion: This national study provides a survey of comorbidities associated with PBC. Hospitalized patients with PBC are more likely to have extrahepatic autoimmune diseases, hepatocellular carcinoma, and biliary tract cancers and a low risk of cardiovascular events.

Association Between Black Race and Presentation and Liver-Related Outcomes of Patients With Autoimmune Hepatitis

INTRODUCTION & AIMS

Small studies have found that black patients with autoimmune hepatitis (AIH) present with more aggressive disease. We aimed to characterize the presentation and outcome in black and white patients with AIH.

METHODS

We performed a retrospective study, collecting information from databases of patients with AIH attending the Institute of Liver studies at King's College Hospital, London (1971-October 2015, the Royal Free Hospital, London (1982 through December 2016) and the multicenter Dutch Autoimmune Hepatitis Study Group cohort (2006-August 2016). We identified 88 black patients with AIH and we compared their clinical characteristics and outcomes to 897 white patients with AIH.

RESULTS

Black patients presented at a younger age (median 38 years vs 45 years) (P = .007), had higher IgG levels (mean 31.0 mg/dL vs 27.5 mg/dL) (P = .04), but there were no significant differences between groups in auto-antibody profiles, International AIH Group scores, or sex distribution of disease. A higher proportion of black patients had systemic lupus erythematosus (10%) than white patients (2%) (P ≤ .001). There was no significant difference in proportions of patients with a response to standard therapy (86% for black patients vs 91% for white patients; P = .20) or in rate of relapse (57% vs 50%; P = .3). Despite this, black patients had an increased risk of liver transplantation and liver-related death (hazard ratio 2.4, 95% confidence interval, 1.4-4.0; P < .001). Overall mortality was similar between the two groups.

CONCLUSION

In a comparison of black and white patients with AIH in Europe, we found that black patients present at a younger age, have higher levels of IgG levels, and a greater proportion have SLE. We also found black patients to have a greater risk of liver transplantation and liver-related mortality, indicating more aggressive disease.

Precision medicine in primary biliary cholangitis

For many years the one-size-fits-all approach has been the only one available to manage patients affected by primary biliary cholangitis. The introduction of obeticholic acid in 2016 as a second-line treatment, together with the creation and validation of several biochemically based scores to stratify the risk of progressive disease, has opened up the need to redefine clinical practice by changing the actual paradigm. The precision medicine initiative is a model of patient-centered health care that aims to improve medicine based on genotypic and molecular characteristics that correlate to specific phenotypic, individual characteristics. In summary, the aim of the precision medicine is to define the right treatment for the right person at the right time. The availability of a second-line disease-modifying drug and new molecules in phase 2 or 3 trials makes this an exciting time for the precision medicine initiative in primary biliary cholangitis. In this review we describe the current risk stratification tools and we track a possible path towards the application of precision medicine in clinical daily life.

Pretreatment prediction of response to ursodeoxycholic acid in primary biliary cholangitis: development and validation of the UDCA Response Score

BACKGROUND

Treatment guidelines recommend a stepwise approach to primary biliary cholangitis: all patients begin treatment with ursodeoxycholic acid (UDCA) monotherapy and those with an inadequate biochemical response after 12 months are subsequently considered for second-line therapies. However, as a result, patients at the highest risk can wait the longest for effective treatment. We determined whether UDCA response can be accurately predicted using pretreatment clinical parameters.

METHODS

We did logistic regression analysis of pretreatment variables in a discovery cohort of patients in the UK with primary biliary cholangitis to derive the best-fitting model of UDCA response, defined as alkaline phosphatase less than 1·67 times the upper limit of normal (ULN), measured after 12 months of treatment with UDCA. We validated the model in an external cohort of patients with primary biliary cholangitis and treated with UDCA in Italy. Additionally, we assessed correlations between model predictions and key histological features, such as biliary injury and fibrosis, on liver biopsy samples.

FINDINGS

2703 participants diagnosed with primary biliary cholangitis between Jan 1, 1998, and May 31, 2015, were included in the UK-PBC cohort for derivation of the model. The following pretreatment parameters were associated with lower probability of UDCA response: higher alkaline phosphatase concentration (p<0·0001), higher total bilirubin concentration (p=0·0003), lower aminotransferase concentration (p=0·0012), younger age (p<0·0001), longer interval from diagnosis to the start of UDCA treatment (treatment time lag, p<0·0001), and worsening of alkaline phosphatase concentration from diagnosis (p<0·0001). Based on these variables, we derived a predictive score of UDCA response. In the external validation cohort, 460 patients diagnosed with primary biliary cholangitis were treated with UDCA, with follow-up data until May 31, 2016. In this validation cohort, the area under the receiver operating characteristic curve for the score was 0·83 (95% CI 0·79-0·87). In 20 liver biopsy samples from patients with primary biliary cholangitis, the UDCA response score was associated with ductular reaction (r=-0·556, p=0·0130) and intermediate hepatocytes (probability of response was 0·90 if intermediate hepatocytes were absent vs 0·51 if present).

INTERPRETATION

We have derived and externally validated a model based on pretreatment variables that accurately predicts UDCA response. Association with histological features provides face validity. This model provides a basis to explore alternative approaches to treatment stratification in patients with primary biliary cholangitis.

FUNDING

UK Medical Research Council and University of Milan-Bicocca.

Gender differences in liver disease and the drug-dose gender gap

Although gender-based medicine is a relatively recent concept, it is now emerging as an important field of research, supported by the finding that many diseases manifest differently in men and women and therefore, might require a different treatment. Sex-related differences regarding the epidemiology, progression and treatment strategies of certain liver diseases have long been known, but most of the epidemiological and clinical trials still report results only about one sex, with consequent different rate of response and adverse reactions to treatment between men and women in clinical practice. This review reports the data found in the literature concerning the gender-related differences for the most representative hepatic diseases.