Anti-Cholestatic Therapy with Obeticholic Acid Improves Short-Term Memory in Bile Duct-Ligated Mice.

Patients with cholestatic liver disease, including those with primary biliary cholangitis, can experience symptoms of impaired cognition or brain fog. This phenomenon remains unexplained and is currently untreatable. Bile duct ligation (BDL) is an established rodent model of cholestasis. In addition to liver changes, BDL animals develop cognitive symptoms early in the disease process (before development of cirrhosis and/or liver failure). The cellular mechanisms underpinning these cognitive symptoms are poorly understood. Herein, the study explored the neurocognitive symptom manifestations, and tested potential therapies, in BDL mice, and used human neuronal cell cultures to explore translatability to humans. BDL animals exhibited short-term memory loss and showed reduced astrocyte coverage of the blood-brain barrier, destabilized hippocampal network activity, and neuronal senescence. Ursodeoxycholic acid (first-line therapy for most human cholestatic diseases) did not reverse symptomatic or mechanistic aspects. In contrast, obeticholic acid (OCA), a farnesoid X receptor agonist and second-line anti-cholestatic agent, normalized memory function, suppressed blood-brain barrier changes, prevented hippocampal network deficits, and reversed neuronal senescence. Co-culture of human neuronal cells with either BDL or human cholestatic patient serum induced cellular senescence and increased mitochondrial respiration, changes that were limited again by OCA. These findings provide new insights into the mechanism of cognitive symptoms in BDL animals, suggesting that OCA therapy or farnesoid X receptor agonism could be used to limit cholestasis-induced neuronal senescence.

Evaluation of tumour surveillance protocols and outcomes in von Hippel-Lindau disease in a national health service.

BACKGROUND: Von Hippel-Lindau (VHL) disease is an inherited tumour predisposition syndrome and a paradigm for the importance of early diagnosis and surveillance. However, there is limited information on the "real world" management of VHL disease. METHODS: A national audit of VHL disease in the United Kingdom. RESULTS: VHL disease was managed mostly via specialist clinics coordinated through regional clinical genetics services (but frequently involving additional specialties). Over the study period, 19 genetic centres saw 842 individuals (393 males, 449 females) with a clinical and/or molecular diagnosis of VHL disease and 74 individuals (35 male, 39 female) with a prior risk of 50% (affected parent). All centres offered retinal, central nervous system and abdominal surveillance to affected individuals and at-risk relatives though surveillance details differed between centres (but complied with international recommendations). Renal lesions detected on the first surveillance scan were, on average, larger than those detected during subsequent scans and the larger the diameter at detection the greater the likelihood of early intervention. CONCLUSIONS: In a state-funded health care system individuals with a rare inherited cancer predisposition syndrome are generally able to access appropriate surveillance and patient management is improved compared to historical data. The "real world" data from this study will inform the future development of VHL management protocols.

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.

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.

Effects of Primary Biliary Cholangitis on Quality of Life and Health Care Costs in the United Kingdom.

BACKGROUND & AIMS: There have been few high-quality studies of the costs, preference-based health-related quality of life (HRQoL) and cost effectiveness of treatments for primary biliary cholangitis (PBC). We aimed to estimate the marginal effects of PBC complications and symptoms, accounting for treatment, on HRQoL and the annual cost of health care in the United Kingdom (UK). These are essential components for evaluation of cost effectiveness and this information will aid in evaluation of new treatments. METHODS: Questionnaires were mailed to 4583 participants in the UK-PBC research cohort and data were collected on HRQoL and use of the National Health Service (NHS) in the UK from 2015 through 2016. HRQoL was measured using the EQ-5D-5L instrument. The annual cost of resource use was calculated using unit costs obtained from NHS sources. We performed econometric analyses to determine the effects of treatment, symptoms, complications, liver transplantation status, and patient characteristics on HRQoL and annual costs. RESULTS: In an analysis of data from 2240 participants (over 10% of all UK PBC patients), we found that PBC symptoms have a considerable effect on HRQoL. Ursodeoxycholic acid therapy was associated with significantly higher HRQoL regardless of response status. Having had a liver transplant and ascites were also independently associated with reduced HRQoL. Having had a liver transplant (US$4294) and esophageal varices (US$3401) were the factors with the two greatest mean annual costs to the NHS. Symptoms were not independently associated with cost but were associated with reduction in HRQoL for patients, indicating the lack of effective treatments for PBC symptoms. CONCLUSIONS: In an analysis of data from 2240 participants in the UK PBC, we found that HRQoL and cost estimates provide greater insight into the relative importance of PBC-related symptoms and complications. These findings provide estimates for health technology assessments of new treatments for PBC.

Amino acid residues in five separate HLA genes can explain most of the known associations between the MHC and primary biliary cholangitis.

Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterised by progressive destruction of intrahepatic bile ducts. The strongest genetic association is with HLA-DQA1*04:01, but at least three additional independent HLA haplotypes contribute to susceptibility. We used dense single nucleotide polymorphism (SNP) data in 2861 PBC cases and 8514 controls to impute classical HLA alleles and amino acid polymorphisms using state-of-the-art methodologies. We then demonstrated through stepwise regression that association in the HLA region can be largely explained by variation at five separate amino acid positions. Three-dimensional modelling of protein structures and calculation of electrostatic potentials for the implicated HLA alleles/amino acid substitutions demonstrated a correlation between the electrostatic potential of pocket P6 in HLA-DP molecules and the HLA-DPB1 alleles/amino acid substitutions conferring PBC susceptibility/protection, highlighting potential new avenues for future functional investigation.

Factors Associated With Outcomes of Patients With Primary Sclerosing Cholangitis and Development and Validation of a Risk Scoring System.

We sought to identify factors that are predictive of liver transplantation or death in patients with primary sclerosing cholangitis (PSC), and to develop and validate a contemporaneous risk score for use in a real-world clinical setting. Analyzing data from 1,001 patients recruited to the UK-PSC research cohort, we evaluated clinical variables for their association with 2-year and 10-year outcome through Cox-proportional hazards and C-statistic analyses. We generated risk scores for short-term and long-term outcome prediction, validating their use in two independent cohorts totaling 451 patients. Thirty-six percent of the derivation cohort were transplanted or died over a cumulative follow-up of 7,904 years. Serum alkaline phosphatase of at least 2.4 × upper limit of normal at 1 year after diagnosis was predictive of 10-year outcome (hazard ratio [HR] = 3.05; C = 0.63; median transplant-free survival 63 versus 108 months; P < 0.0001), as was the presence of extrahepatic biliary disease (HR = 1.45; P = 0.01). We developed two risk scoring systems based on age, values of bilirubin, alkaline phosphatase, albumin, platelets, presence of extrahepatic biliary disease, and variceal hemorrhage, which predicted 2-year and 10-year outcomes with good discrimination (C statistic = 0.81 and 0.80, respectively). Both UK-PSC risk scores were well-validated in our external cohort and outperformed the Mayo Clinic and aspartate aminotransferase-to-platelet ratio index (APRI) scores (C statistic = 0.75 and 0.63, respectively). Although heterozygosity for the previously validated human leukocyte antigen (HLA)-DR*03:01 risk allele predicted increased risk of adverse outcome (HR = 1.33; P = 0.001), its addition did not improve the predictive accuracy of the UK-PSC risk scores. Conclusion: Our analyses, based on a detailed clinical evaluation of a large representative cohort of participants with PSC, furthers our understanding of clinical risk markers and reports the development and validation of a real-world scoring system to identify those patients most likely to die or require liver transplantation.

Pruritus Is Common and Undertreated in Patients With Primary Biliary Cholangitis in the United Kingdom.

BACKGROUND AND AIMS: Little is known about the prevalence or treatment of pruritus associated with primary biliary cholangitis (PBC). We analyzed data from patients with PBC recruited from all clinical centers in the United Kingdom (UK) to characterize the prevalence, severity, progression, and treatment of pruritus. METHODS: We performed cross-sectional and longitudinal studies of patients in the UK-PBC cohort to assess trajectories of pruritus. Data on pruritus frequency, severity, and therapy were collected via paper questionnaires completed by 2194 patients at their initial assessment in 2011 and then again in 2014 and 2017. Self-reported treatment data were validated against the prescription record of PBC cohort in the Clinical Practice Research Datalink, a primary care database. We defined persistent pruritus as itch that occurs frequently or all the time and severe pruritus as PBC-40 pruritus domain scores of 12 or more, throughout their disease course. Latent class mixed models were used to study pruritus trajectories and identify factors associated with high pruritus. RESULTS: At initial assessment, 1613 (73.5%) patients had experienced pruritus at some point since their development of PBC-persistent pruritus was reported by 34.5% of the patients and severe pruritus by 11.7%. Only 37.4% of patients with persistent pruritus and 50% with severe pruritus reported ever receiving cholestyramine. Frequencies of rifampicin use were 11% in patients with persistent pruritus and 23% in patients with severe pruritus. Comparison of 2011 and 2014 surveys (comprising 1423 patients) showed consistent self-reported data on pruritus. Proportions of patients in the UK-PBC cohort treated with cholestyramine or naltrexone (37.4% and 4.4%) did not differ significantly from proportions treated in the Clinical Practice Research Datalink cohort (30.4% and 4.4%) (P = .07 for cholestyramine and P = .32 for naltrexone). Latent class mixed models (n = 1753) identified 3 different groups of pruritus. Multivariable analysis identified younger age at diagnosis and higher level of alkaline phosphatase at 12 months after diagnosis as factors significantly associated with persistent high pruritus. CONCLUSIONS: In a large national cohort study of patients with PBC, we found a high prevalence of pruritus and inadequate guideline-recommended therapy. Patient-reported data used to determine pruritus prevalence and treatment are reliable. Younger age and levels of higher alkaline phosphatase were associated with persistent pruritus. We need to increase awareness and management of pruritus in PBC in the UK.

Glycine Amidinotransferase (GATM), Renal Fanconi Syndrome, and Kidney Failure.

Background For many patients with kidney failure, the cause and underlying defect remain unknown. Here, we describe a novel mechanism of a genetic order characterized by renal Fanconi syndrome and kidney failure.Methods We clinically and genetically characterized members of five families with autosomal dominant renal Fanconi syndrome and kidney failure. We performed genome-wide linkage analysis, sequencing, and expression studies in kidney biopsy specimens and renal cells along with knockout mouse studies and evaluations of mitochondrial morphology and function. Structural studies examined the effects of recognized mutations.Results The renal disease in these patients resulted from monoallelic mutations in the gene encoding glycine amidinotransferase (GATM), a renal proximal tubular enzyme in the creatine biosynthetic pathway that is otherwise associated with a recessive disorder of creatine deficiency. In silico analysis showed that the particular GATM mutations, identified in 28 members of the five families, create an additional interaction interface within the GATM protein and likely cause the linear aggregation of GATM observed in patient biopsy specimens and cultured proximal tubule cells. GATM aggregates-containing mitochondria were elongated and associated with increased ROS production, activation of the NLRP3 inflammasome, enhanced expression of the profibrotic cytokine IL-18, and increased cell death.Conclusions In this novel genetic disorder, fully penetrant heterozygous missense mutations in GATM trigger intramitochondrial fibrillary deposition of GATM and lead to elongated and abnormal mitochondria. We speculate that this renal proximal tubular mitochondrial pathology initiates a response from the inflammasome, with subsequent development of kidney fibrosis.

The UK-PBC risk scores: Derivation and validation of a scoring system for long-term prediction of end-stage liver disease in primary biliary cholangitis.

UNLABELLED: The biochemical response to ursodeoxycholic acid (UDCA)--so-called "treatment response"--strongly predicts long-term outcome in primary biliary cholangitis (PBC). Several long-term prognostic models based solely on the treatment response have been developed that are widely used to risk stratify PBC patients and guide their management. However, they do not take other prognostic variables into account, such as the stage of the liver disease. We sought to improve existing long-term prognostic models of PBC using data from the UK-PBC Research Cohort. We performed Cox's proportional hazards regression analysis of diverse explanatory variables in a derivation cohort of 1,916 UDCA-treated participants. We used nonautomatic backward selection to derive the best-fitting Cox model, from which we derived a multivariable fractional polynomial model. We combined linear predictors and baseline survivor functions in equations to score the risk of a liver transplant or liver-related death occurring within 5, 10, or 15 years. We validated these risk scores in an independent cohort of 1,249 UDCA-treated participants. The best-fitting model consisted of the baseline albumin and platelet count, as well as the bilirubin, transaminases, and alkaline phosphatase, after 12 months of UDCA. In the validation cohort, the 5-, 10-, and 15-year risk scores were highly accurate (areas under the curve: >0.90). CONCLUSIONS: The prognosis of PBC patients can be accurately evaluated using the UK-PBC risk scores. They may be used to identify high-risk patients for closer monitoring and second-line therapies, as well as low-risk patients who could potentially be followed up in primary care.

Vascular Endothelial Growth Factor C for Polycystic Kidney Diseases.

Polycystic kidney diseases (PKD) are genetic disorders characterized by progressive epithelial cyst growth leading to destruction of normally functioning renal tissue. Current therapies have focused on the cyst epithelium, and little is known about how the blood and lymphatic microvasculature modulates cystogenesis. Hypomorphic Pkd1(nl/nl) mice were examined, showing that cystogenesis was associated with a disorganized pericystic network of vessels expressing platelet/endothelial cell adhesion molecule 1 and vascular endothelial growth factor receptor 3 (VEGFR3). The major ligand for VEGFR3 is VEGFC, and there were lower levels of Vegfc mRNA within the kidneys during the early stages of cystogenesis in 7-day-old Pkd1(nl/nl) mice. Seven-day-old mice were treated with exogenous VEGFC for 2 weeks on the premise that this would remodel both the VEGFR3(+) pericystic vascular network and larger renal lymphatics that may also affect the severity of PKD. Treatment with VEGFC enhanced VEGFR3 phosphorylation in the kidney, normalized the pattern of the pericystic network of vessels, and widened the large lymphatics in Pkd1(nl/nl) mice. These effects were associated with significant reductions in cystic disease, BUN and serum creatinine levels. Furthermore, VEGFC administration reduced M2 macrophage pericystic infiltrate, which has been implicated in the progression of PKD. VEGFC administration also improved cystic disease in Cys1(cpk/cpk) mice, a model of autosomal recessive PKD, leading to a modest but significant increase in lifespan. Overall, this study highlights VEGFC as a potential new treatment for some aspects of PKD, with the possibility for synergy with current epithelially targeted approaches.

Multiple postnatal craniofacial anomalies are characterized by conditional loss of polycystic kidney disease 2 (Pkd2).

Polycystin 2 (Pkd2), which belongs to the transient receptor potential family, plays a critical role in development. Pkd2 is mainly localized in the primary cilia, which also function as mechanoreceptors in many cells that influence multiple biological processes including Ca(2+) influx, chemical activity and signalling pathways. Mutations in many cilia proteins result in craniofacial abnormalities. Orofacial tissues constantly receive mechanical forces and are known to develop and grow through intricate signalling pathways. Here we investigate the role of Pkd2, whose role remains unclear in craniofacial development and growth. In order to determine the role of Pkd2 in craniofacial development, we located expression in craniofacial tissues and analysed mice with conditional deletion of Pkd2 in neural crest-derived cells, using Wnt1Cre mice. Pkd2 mutants showed many signs of mechanical trauma such as fractured molar roots, distorted incisors, alveolar bone loss and compressed temporomandibular joints, in addition to abnormal skull shapes. Significantly, mutants showed no indication of any of these phenotypes at embryonic stages when heads perceive no significant mechanical stress in utero. The results suggest that Pkd2 is likely to play a critical role in craniofacial growth as a mechanoreceptor. Pkd2 is also identified as one of the genes responsible for autosomal dominant polycystic kidney disease (ADPKD). Since facial anomalies have never been identified in ADPKD patients, we carried out three-dimensional photography of patient faces and analysed these using dense surface modelling. This analysis revealed specific characteristics of ADPKD patient faces, some of which correlated with those of the mutant mice.

Implications of genome-wide association studies in novel therapeutics in primary biliary cirrhosis.

Genome-wide association studies (GWAS) have revolutionized the search for genetic influences on complex disorders, such as primary biliary cirrhosis (PBC). Recent GWAS have identified many disease-associated genetic variants. These, overall, highlighted the remarkable contribution of key immunological pathways in PBC that may be involved in the initial mechanisms of loss of tolerance and the subsequent inflammatory response and chronic bile duct damage. Results from GWAS have the potential to be translated in biological knowledge and, hopefully, clinical application. There are a number of immune pathways highlighted in GWAS that may have therapeutic implications in PBC and in other autoimmune diseases, such as the anti-interleukin-12/interleukin-23, nuclear factor-kb, tumor necrosis factor, phosphatidylinositol signaling and hedgehog signaling pathways. Further areas in which GWAS findings are leading to clinical applications either in PBC or in other autoimmune conditions, include disease classification, risk prediction and drug development. In this review we outline the possible next steps that may help accelerate progress from genetic studies to the biological knowledge that would guide the development of predictive, preventive, or therapeutic measures in PBC.

Sex and age are determinants of the clinical phenotype of primary biliary cirrhosis and response to ursodeoxycholic acid.

UNLABELLED: BACKGROUND, & AIMS: Studies of primary biliary cirrhosis (PBC) phenotypes largely have been performed using small and selected populations. Study size has precluded investigation of important disease subgroups, such as men and young patients. We used a national patient cohort to obtain a better picture of PBC phenotypes. METHODS: We performed a cross-sectional study using the United Kingdom-PBC, patient cohort. Comprehensive data were collected for 2353 patients on diagnosis reports, response to therapy with ursodeoxycholic acid (UDCA), laboratory results, and symptom impact (assessed using the PBC-40 and other related measures). RESULTS: Seventy-nine percent of the patients reported current UDCA, therapy, with 80% meeting Paris response criteria. Men were significantly less likely to have responded to UDCA than women (72% vs 80% response rate; P < .05); male sex was an independent predictor of nonresponse on multivariate analysis. Age at diagnosis was associated strongly and independently with response to UDCA; response rates ranged from 90% among patients who presented with PBC when they were older than age 70, to less than 50% for those younger than age 30 (P < .0001). Patients who presented at younger ages also were significantly more likely not to respond to UDCA therapy, based on alanine aminotransferase and aspartate aminotransferase response criteria, and more likely to report fatigue and pruritus. Women had mean fatigue scores 32% higher than men's (P < .0001). The increase in fatigue severity in women was related strongly (r = 0.58; P < .0001) to higher levels of autonomic symptoms (P < .0001). CONCLUSIONS: Among patients with PBC, response to UDCA, treatment and symptoms are related to sex and age at presentation, with the lowest response rates and highest levels of symptoms in women presenting at younger than age 50. Increased severity of fatigue in women is related to increased autonomic symptoms, making dysautonomia a plausible therapeutic target.

Impact of primary biliary cirrhosis on perceived quality of life: the UK-PBC national study.

UNLABELLED: Primary biliary cirrhosis (PBC) has a complex clinical phenotype, with debate about the extent and specificity of frequently described systemic symptoms such as fatigue. The aim of this study was to use a national patient cohort of 2,353 patients recruited from all clinical centers in the UK to explore the impact of disease on perceived life quality. Clinical data regarding diagnosis, therapy, and biochemical status were collected and have been reported previously. Detailed symptom phenotyping using recognized and validated symptom assessment tools including the PBC-40 was also undertaken and is reported here. Perception of poor quality of life and impaired health status was common in PBC patients (35% and 46%, respectively) and more common than in an age-matched and sex-matched community control group (6% and 15%, P < 0.0001 for both). Fatigue and symptoms of social dysfunction were associated with impaired perceived quality of life using multivariate analysis. Fatigue was the symptom with the greatest impact. Depression was a significant factor, but appeared to be a manifestation of complex symptom burden rather than a primary event. Fatigue had its greatest impact on perceived quality of life when accompanied by symptoms of social dysfunction, suggesting that maintenance of social networks is critical for minimizing the impact of fatigue. CONCLUSION: The symptom burden in PBC, which is unrelated to disease severity or ursodeoxycholic acid response, is significant and complex and results in significant quality of life deficit. The complexity of symptom burden, and its lack of relation to disease severity and treatment response, suggest that specific approaches to symptom management are warranted that address both symptom biology and social impact.

The impact of liver transplantation on the phenotype of primary biliary cirrhosis patients in the UK-PBC cohort.

BACKGROUND & AIMS: Liver transplantation improves survival in end-stage primary biliary cirrhosis (PBC), but the benefit for systemic symptoms including fatigue is less clear. The aim of this study was to utilise the comprehensive UK-PBC Research Cohort, including 380 post-transplant patients and 2300 non-transplanted patients, to answer key questions regarding transplantation for PBC. METHODS: Cross-sectional study of post-transplant PBC patients and case-matched non-transplanted patients. Detailed clinical information was collected, together with patient systemic symptom impact data using validated assessment tools. RESULTS: Over 25% of patients in the transplant cohort were grafted within 2 years of PBC diagnosis suggesting advanced disease at presentation. Transplanted patients were significantly younger at presentation than non-transplanted (mean 7 years) and >35% of all patients in the UK-PBC cohort who presented under 50 years had already undergone liver transplantation at the study censor point (>50% were treatment failures (post-transplant or unresponsive to UDCA)). Systemic symptom severity (fatigue and cognitive symptoms) was identical in female post-transplant patients and matched non-transplanted controls and unrelated to disease recurrence or immunosuppression type. In males, symptoms were worse in transplanted than in non-transplanted patients. CONCLUSIONS: Age at presentation is a major risk factor for progression to transplant (as well as UDCA non-response) in PBC. Although both confirmatory longitudinal studies, and studies utilising objective as well as subjective measures of function, are needed if we are to address the question definitively, we found no evidence of improved systemic symptoms after liver transplantation in PBC and patients should be advised accordingly. Consideration needs to be given to enhancing rehabilitation approaches to improve function and life quality after liver transplant for PBC.

Regulation of immune responses in primary biliary cholangitis: a transcriptomic analysis of peripheral immune cells.

BACKGROUND AIMS: In patients with primary biliary cholangitis (PBC), the serum liver biochemistry measured during treatment with ursodeoxycholic acid-the UDCA response-accurately predicts long-term outcome. Molecular characterization of patients stratified by UDCA response can improve biological understanding of the high-risk disease, thereby helping to identify alternative approaches to disease-modifying therapy. In this study, we sought to characterize the immunobiology of the UDCA response using transcriptional profiling of peripheral blood mononuclear cell subsets. METHODS: We performed bulk RNA-sequencing of monocytes and TH1, TH17, TREG, and B cells isolated from the peripheral blood of 15 PBC patients with adequate UDCA response ("responders"), 16 PBC patients with inadequate UDCA response ("nonresponders"), and 15 matched controls. We used the Weighted Gene Co-expression Network Analysis to identify networks of co-expressed genes ("modules") associated with response status and the most highly connected genes ("hub genes") within them. Finally, we performed a Multi-Omics Factor Analysis of the Weighted Gene Co-expression Network Analysis modules to identify the principal axes of biological variation ("latent factors") across all peripheral blood mononuclear cell subsets. RESULTS: Using the Weighted Gene Co-expression Network Analysis, we identified modules associated with response and/or disease status (q<0.05) in each peripheral blood mononuclear cell subset. Hub genes and functional annotations suggested that monocytes are proinflammatory in nonresponders, but antiinflammatory in responders; TH1 and TH17 cells are activated in all PBC cases but better regulated in responders; and TREG cells are activated-but also kept in check-in responders. Using the Multi-Omics Factor Analysis, we found that antiinflammatory activity in monocytes, regulation of TH1 cells, and activation of TREG cells are interrelated and more prominent in responders. CONCLUSIONS: We provide evidence that adaptive immune responses are better regulated in patients with PBC with adequate UDCA response.