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OBJECTIVES: Obeticholic acid (OCA) treatment for primary biliary cholangitis (PBC) was conditionally approved in the phase 3 POISE trial. The COBALT confirmatory trial assessed whether clinical outcomes in PBC patients improve with OCA therapy. METHODS: Patients randomized to OCA (5-10 mg) were compared with placebo (randomized controlled trial [RCT]) or external control (EC). The primary composite endpoint was time to death, liver transplant, model for end-stage liver disease score ≥15, uncontrolled ascites, or hospitalization for hepatic decompensation. A prespecified propensity score-weighted EC group was derived from a US healthcare claims database. RESULTS: In the RCT, the primary endpoint occurred in 28.6% of OCA (n=168) and 28.9% of placebo patients (n=166; intent-to-treat [ITT] analysis hazard ratio [HR]=1.01, 95% CI=0.68-1.51), but functional unblinding and crossover to commercial therapy occurred, especially in the placebo arm. Correcting for these using inverse probability of censoring weighting (IPCW) and as-treated analyses shifted the HR to favor OCA. In the EC (n=1051), the weighted primary endpoint occurred in 10.1% of OCA and 21.5% of non-OCA patients (HR=0.39; 95% CI=0.22-0.69; P=0.001). No new safety signals were identified in the RCT. CONCLUSIONS: Functional unblinding and treatment crossover, particularly in the placebo arm, confounded the ITT estimate of outcomes associated with OCA in the RCT. Comparison with the real-world EC showed that OCA treatment significantly reduced the risk of negative clinical outcomes. These analyses demonstrate the value of EC data in confirmatory trials and suggest that treatment with OCA improves clinical outcomes in patients with PBC.
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BACKGROUND AIMS: Primary sclerosing cholangitis (PSC) may reoccur following liver transplantation (LT) and the diagnosis established once imaging studies demonstrate the diagnostic cholangiographic appearance. To evaluate whether the development of recurrent PSC (rPSC) is associated with cholestasis soon after LT, we studied whether changes in hepatic biochemistry within the first 12 months were linked with the development of rPSC and graft loss. METHODS: We conducted a retrospective cohort analysis of 158 transplant recipients with PSC in Canada, and 549 PSC transplant recipients from the United Kingdom. We evaluated serum liver tests within 12 months after LT and the subsequent development of a cholangiographic diagnosis of rPSC as a time-dependent covariate using Cox regression. Severe cholestasis was defined as either alkaline phosphatase> 3xupper limit of normal or total bilirubin> 100 µmol/L. RESULTS: Patients who developed rPSC were more likely to have severe cholestasis versus those without at 3 months (20.5% vs 8.2%, p=0.011), at 6 months (17.9% vs. 10.0%, p=0.026) and 12 months (15.4% vs. 7.8%, p=0.051) in the Canadian cohort and at 12 months in the UK cohort (27.9% vs. 12.6%, p<0.0001). By multivariable analysis, development of severe cholestasis in the Canadian cohort at 3 months (HR=2.41, p=0.046) and in the UK cohort at 12 months (HR=3.141, p<0.0001) were both associated with rPSC. Severe cholestasis at 3 months in the Canadian cohort was predictive of graft loss (HR=3.88, p=0.0001). CONCLUSIONS: The development of cholestasis within 3 to 12 months following LT was predictive of rPSC and graft loss.
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BACKGROUND & AIMS: Treatment outcomes for people living with autoimmune hepatitis (AIH) are limited by a lack of specific therapies, as well as limited well-validated prognostic tools and clinical trial endpoints. We sought to identify predictors of outcome for people living with AIH. METHODS: We evaluated the clinical course of people with AIH across 11 Canadian centres. Biochemical changes were analysed using linear mixed-effect and logistic regression. Clinical outcome was dynamically modelled using time-varying Cox proportional hazard modelling and landmark analysis. RESULTS: In 691 patients (median age 49 years, 75.4% female), with a median follow-up of 6 years (25th-75th percentile, 2.5-11), 118 clinical events occurred. Alanine aminotransferase (ALT) normalisation occurred in 63.8% of the cohort by 12 months. Older age at diagnosis (odd ratio [OR] 1.19, 95% CI 1.06-1.35) and female sex (OR 1.94, 95% CI 1.18-3.19) were associated with ALT normalisation at 6 months, whilst baseline cirrhosis status was associated with reduced chance of normalisation at 12 months (OR 0.52, 95% CI 0.33-0.82). Baseline total bilirubin, aminotransferases, and IgG values, as well as initial prednisone dose, did not predict average ALT reduction. At baseline, older age (hazard ratio [HR] 1.25, 95% CI 1.12-1.40), cirrhosis at diagnosis (HR 3.67, 95% CI 2.48-5.43), and elevated baseline total bilirubin (HR 1.36, 95% CI 1.17-1.58) increased the risk of clinical events. Prolonged elevations in ALT (HR 1.07, 95% CI 1.00-1.13) and aspartate aminotransferase (HR 1.13, 95% CI 1.06-1.21), but not IgG (HR 1.01, 95% CI 0.95-1.07), were associated with higher risk of clinical events. Higher ALT at 6 months was associated with worse clinical event-free survival. CONCLUSION: In people living with AIH, sustained elevated aminotransferase values, but not IgG, are associated with poorer long-term outcomes. Biochemical response and long-term survival are not associated with starting prednisone dose. IMPACT AND IMPLICATIONS: Using clinical data from multiple Canadian liver clinics treating autoimmune hepatitis (AIH), we evaluate treatment response and clinical outcomes. For the first time, we apply mixed-effect and time-varying survival statistical methods to rigorously examine treatment response and the impact of fluctuating liver biochemistry on clinical event-free survival. Key to the study impact, our data is 'real-world', represents a diverse population across Canada, and uses continuous measurements over follow-up. Our results challenge the role of IgG as a marker of treatment response and if normalisation of IgG should remain an important part of the definition of biochemical remission. Our analysis further highlights that baseline markers of disease severity may not prognosticate early treatment response. Additionally, the initial prednisone dose may be less relevant for achieving aminotransferase normalisation. This is important for patients and treating clinicians given the relevance and importance of side effects.
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Alanina Transaminasa , Hepatitis Autoinmune , Humanos , Hepatitis Autoinmune/tratamiento farmacológico , Hepatitis Autoinmune/mortalidad , Hepatitis Autoinmune/sangre , Hepatitis Autoinmune/diagnóstico , Femenino , Masculino , Persona de Mediana Edad , Canadá/epidemiología , Adulto , Alanina Transaminasa/sangre , Prednisona/uso terapéutico , Prednisona/administración & dosificación , Estudios de Cohortes , Resultado del Tratamiento , Pronóstico , Bilirrubina/sangre , Estudios de Seguimiento , Modelos de Riesgos Proporcionales , Inmunoglobulina G/sangreRESUMEN
Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated. We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud's symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients. All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR. SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity. Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.
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Síndrome de Fatiga Crónica , Humanos , Síndrome de Fatiga Crónica/diagnóstico , Mitocondrias/genética , Biomarcadores , ADN Mitocondrial/genética , Encuestas y CuestionariosRESUMEN
BACKGROUND AND AIMS: Patients with primary biliary cholangitis (PBC) and insufficient response to ursodeoxycholic acid (UDCA), currently assessed after 1 year, are candidates for second-line therapy. The aims of this study are to assess biochemical response pattern and determine the utility of alkaline phosphatase (ALP) at six months as a predictor of insufficient response. METHODS: UDCA-treated patients in the GLOBAL PBC database with available liver biochemistries at one year were included. POISE criteria were used to assess response to treatment, defined as ALP <1.67 × upper limit of normal (ULN) and normal total bilirubin at one year. Various thresholds of ALP at six months were evaluated to predict insufficient response based on negative predictive value (NPV) and that with nearest to 90% NPV was selected. RESULTS: For the study, 1362 patients were included, 1232 (90.5%) female, mean age of 54 years. The POISE criteria were met by 56.4% (n = 768) of patients at one year. The median ALP (IQR) of those who met POISE criteria compared to those who did not was 1.05 × ULN (0.82-1.33) vs. 2.37 × ULN (1.72-3.69) at six months (p < .001). Of 235 patients with serum ALP >1.9 × ULN at six months, 89% did not achieve POISE criteria (NPV) after one year of UDCA. Of those with insufficient response by POISE criteria at one year, 210 (67%) had an ALP >1.9 × ULN at six months and thus would have been identified early. CONCLUSIONS: We can identify patients for second-line therapy at six months using an ALP threshold of 1.9 × ULN, given that approximately 90% of these patients are non-responders according to POISE criteria.
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Cirrosis Hepática Biliar , Humanos , Femenino , Persona de Mediana Edad , Masculino , Cirrosis Hepática Biliar/diagnóstico , Cirrosis Hepática Biliar/tratamiento farmacológico , Fosfatasa Alcalina , Colagogos y Coleréticos/uso terapéutico , Bilirrubina , Ácido Ursodesoxicólico/uso terapéuticoRESUMEN
INTRODUCTION: Treatment of primary biliary cholangitis (PBC) can improve the GLOBE score. We aimed to assess the association between changes in the GLOBE score (ΔGLOBE) and liver transplantation (LT)-free survival in patients with PBC who were treated with ursodeoxycholic acid (UDCA). METHODS: Among UDCA-treated patients within the Global PBC cohort, the association between ΔGLOBE (ΔGLOBE 0-1 : during the first year of UDCA, ΔGLOBE 1-2 : during the second year) and the risk of LT or death was assessed through Cox regression analyses. RESULTS: Overall, 3,775 UDCA-treated patients were included; 3,424 (90.7%) were female, the median age was 54.0 (interquartile range [IQR] 45.9-62.4) years, and the median baseline GLOBE score was 0.25 (IQR -0.47 to 0.96). During a median follow-up of 7.2 (IQR 3.7-11.5) years, 730 patients reached the combined end point of LT or death. The median ΔGLOBE 0-1 was -0.27 (IQR -0.56 to 0.02). Cox regression analyses, adjusted for pretreatment GLOBE score and ΔGLOBE 0-12 , showed that ΔGLOBE was associated with LT or death (adjusted hazard ratio 2.28, 95% confidence interval 1.81-2.87, P < 0.001). The interaction between baseline GLOBE score and ΔGLOBE 0-1 was not statistically significant ( P = 0.296). The ΔGLOBE 1-2 was associated with LT or death (adjusted hazard ratio 2.19, 95% confidence interval 1.67-2.86, P < 0.001), independently from the baseline GLOBE score and the change in GLOBE score during the first year of UDCA. DISCUSSION: UDCA-induced changes in the GLOBE score were significantly associated with LT-free survival in patients with PBC. While the relative risk reduction of LT or death was stable, the absolute risk reduction was heavily dependent on the baseline prognosis of the patient.
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Cirrosis Hepática Biliar , Ácido Ursodesoxicólico , Humanos , Femenino , Persona de Mediana Edad , Masculino , Ácido Ursodesoxicólico/uso terapéutico , Cirrosis Hepática Biliar/tratamiento farmacológico , Cirrosis Hepática Biliar/cirugía , Colagogos y Coleréticos/uso terapéutico , Resultado del Tratamiento , Estudios RetrospectivosRESUMEN
BACKGROUND AND AIMS: The are geographic variations in the incidence and prevalence of primary biliary cholangitis (PBC). The aim was to explore whether clinical outcomes of patients within Western Europe differ according to geographical region. METHODS: Ursodeoxycholic acid-treated patients from European centers from the Global PBC database diagnosed from 1990 onwards were included. Patients with a time lag > 1 year from diagnosis to start of follow-up were excluded. Differences in baseline characteristics were studied according to North/South and East/West, whereas outcomes (transplant-free survival and decompensation) were studied with center latitude and longitude. Cox regression analyses were adjusted for age, sex, diagnosis year, biochemical markers, and cirrhosis as a time-dependent covariate. RESULTS: One thousand eight hundred seventy-eight patients were included, and there were no geographical differences in age or sex, with a mean age of 54 years and 89% female patients. Those in North Europe were more often of a moderately advanced/advanced Rotterdam biochemical stage (28.4%) compared with South Europe (20.6%). Additionally, they exhibited higher median alkaline phosphatase (2.0 ×ULN vs. 1.4 ×ULN) and transaminases. In multivariable analysis, there was a significant interaction between center latitude and longitude for decompensation (P < 0.001) and a trend for transplant-free survival, in which the Northwestern area demonstrated an increased risk for poor outcomes as compared to the reference (Paris). CONCLUSION: We describe geographic variations in outcomes for patients across Europe from specialist centers in the Global PBC Study Group. Further study is important to explore the potential individual, environmental, and healthcare-related factors that may be contributors.
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Cirrosis Hepática Biliar , Humanos , Femenino , Persona de Mediana Edad , Masculino , Cirrosis Hepática Biliar/diagnóstico , Cirrosis Hepática Biliar/tratamiento farmacológico , Cirrosis Hepática Biliar/epidemiología , Europa (Continente)/epidemiología , Bases de Datos Factuales , Supervivencia de Injerto , Cirrosis HepáticaAsunto(s)
Betaretrovirus , Neoplasias de la Mama , Animales , Ratones , Humanos , Femenino , Virus del Tumor Mamario del RatónRESUMEN
BACKGROUND: After 1 year of ursodeoxycholic acid (UDCA), patients with primary biliary cholangitis (PBC) may have a normal GLOBE score despite high alkaline phosphatase (ALP) levels. AIM: To assess the association between ALP and liver transplantation (LT)-free survival according to the GLOBE score METHODS: Among patients with a normal or elevated GLOBE score in the Global PBC cohort, the association between ALP after 1 year of UDCA and the risk of LT/death was assessed. The LT-free survival was compared with that of a matched general population. RESULTS: After 1 year of UDCA, ALP was associated with the risk of LT/death (aHR 1.31, 95% CI 1.003-1.72, p = 0.048) among 2729 patients with a normal GLOBE score. The 10-year LT-free survival among these patients with an ALP >2.0 × ULN was 94.0% (95% CI 90.1-97.9) for those <50 years, and 82.6% (95% CI 76.5-88.7) for those ≥50 years, which was significantly lower (p = 0.040) and similar (p = 0.736) to that of the matched population, respectively. The 10-year LT-free survival in patients ≥50 years with normal GLOBE score and normal ALP (90.8%, 95% CI 87.7-93.9) was significantly higher (p = 0.022) than the matched population. Among 1045 patients with an elevated GLOBE score, ALP was associated with LT/death only in those <50 years (aHR 1.38, 95% CI 1.06-1.81, p = 0.016). CONCLUSION: The LT-free survival of patients with PBC with a normal GLOBE score is optimal in case of normal ALP levels, also in relation to the general population. Despite their generally favourable prognosis, an elevated ALP level may still indicate a need for add-on therapy.
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Cirrosis Hepática Biliar , Trasplante de Hígado , Fosfatasa Alcalina , Colagogos y Coleréticos/uso terapéutico , Humanos , Cirrosis Hepática Biliar/diagnóstico , Cirrosis Hepática Biliar/tratamiento farmacológico , Cirrosis Hepática Biliar/cirugía , Ácido Ursodesoxicólico/uso terapéuticoRESUMEN
Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by the production of diagnostic antimitochondrial antibodies (AMA) reactive to the pyruvate dehydrogenase complex. A human betaretrovirus (HBRV) resembling mouse mammary tumor virus has been characterized in patients with PBC. However, linking the viral infection with the disease is not a straight-forward process because PBC is a complex multifactorial disease influenced by genetic, hormonal, autoimmune, environmental, and other factors. Currently, PBC is assumed to have an autoimmune etiology, but the evidence is lacking to support this conjecture. In this review, we describe different approaches connecting HBRV with PBC. Initially, we used co-cultivation of HBRV with biliary epithelial cells to trigger the PBC-specific phenotype with cell surface expression of cryptic mitochondrial autoantigens linked with antimitochondrial antibody expression. Subsequently, we have derived layers of proof to support the role of betaretrovirus infection in mouse models of autoimmune biliary disease with spontaneous AMA production and in patients with PBC. Using Hill's criteria, we provide an overview of how betaretrovirus infection may trigger autoimmunity and propagate biliary disease. Ultimately, the demonstration that disease can be cured with antiviral therapy may sway the argument toward an infectious disease etiology in an analogous fashion that was used to link H. pylori with peptic ulcer disease.
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Betaretrovirus , Cirrosis Hepática Biliar , Hepatopatías , Animales , Antivirales/uso terapéutico , Autoanticuerpos , Autoantígenos , Autoinmunidad , Humanos , Cirrosis Hepática Biliar/tratamiento farmacológico , Cirrosis Hepática Biliar/patología , Ratones , Complejo Piruvato Deshidrogenasa/uso terapéuticoRESUMEN
BACKGROUND & AIMS: The Primary Biliary Cholangitis (PBC) Obeticholic Acid (OCA) International Study of Efficacy (POISE) randomized, double-blind, placebo-controlled trial demonstrated that OCA reduced biomarkers associated with adverse clinical outcomes (ie, alkaline phosphatase, bilirubin, aspartate aminotransferase, and alanine aminotransferase) in patients with PBC. The objective of this study was to evaluate time to first occurrence of liver transplantation or death in patients with OCA in the POISE trial and open-label extension vs comparable non-OCA-treated external controls. METHODS: Propensity scores were generated for external control patients meeting POISE eligibility criteria from 2 registry studies (Global PBC and UK-PBC) using an index date selected randomly between the first and last date (inclusive) on which eligibility criteria were met. Cox proportional hazards models weighted by inverse probability of treatment assessed time to death or liver transplantation. Additional analyses (Global PBC only) added hepatic decompensation to the composite end point and assessed efficacy in patients with or without cirrhosis. RESULTS: During the 6-year follow-up, there were 5 deaths or liver transplantations in 209 subjects in the POISE cohort (2.4%), 135 of 1381 patients in the Global PBC control (10.0%), and 281 of 2135 patients in the UK-PBC control (13.2%). The hazard ratios (HRs) for the primary outcome were 0.29 (95% CI, 0.10-0.83) for POISE vs Global PBC and 0.30 (95% CI, 0.12-0.75) for POISE vs UK-PBC. In the Global PBC study, HR was 0.20 (95% CI, 0.03-1.22) for patients with cirrhosis and 0.31 (95% CI, 0.09-1.04) for those without cirrhosis; HR was 0.42 (95% CI, 0.21-0.85) including hepatic decompensation. CONCLUSIONS: Patients treated with OCA in a trial setting had significantly greater transplant-free survival than comparable external control patients.
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Cirrosis Hepática Biliar , Ácido Ursodesoxicólico , Humanos , Ácido Ursodesoxicólico/efectos adversos , Cirrosis Hepática Biliar/diagnóstico , Cirrosis Hepática Biliar/tratamiento farmacológico , Cirrosis Hepática Biliar/cirugía , Ácido Quenodesoxicólico/efectos adversos , Cirrosis Hepática/complicacionesRESUMEN
BACKGROUND: Primary sclerosing cholangitis (PSC) is an immune-mediated biliary disorder of unknown etiology with no effective treatment. The purpose of this study was to better prognosticate the development of cirrhosis, decompensation, and requirement for liver transplantation (LT) in PSC patients based on serum immunoglobulin G4 (IgG4) levels. METHODS: A retrospective chart review was conducted on PSC patients seen at the University of Alberta Hospital between 2002 and 2017. PSC patients were categorized as high IgG4 group (≥70 mg/dL) or normal IgG4 group (<70 mg/dL). Laboratory parameters, clinical characteristics, and outcomes were compared between the groups. RESULTS: One hundred and ten patients were followed over a mean period of 7.3 (SD 5) years. Seventy-two patients (66%) were male, the mean age at diagnosis of PSC was 35 (SD 15) years, and inflammatory bowel disease (IBD) was present in 80 patients (73%). High IgG4 levels were found in 37 patients (34%). PSC patients with high IgG4 had a shorter mean cholangitis-free survival time (5.3 versus 10.4 years, p = 0.02), cirrhosis-free survival time (8.7 versus 13.0 years, p = 0.02), and LT-free survival time (9.3 years versus 18.9 years, p <0.001). IgG4 ≥70 mg/dL was independently associated with liver decompensation and LT-free outcomes. A cut-off IgG4 value of ≥70 mg/dL performed better than a cut-off value of ≥140 mg/dL to predict time to LT (area under the curve [AUC] 0.68, p = 0.03, sensitivity 72%, specificity 78%). CONCLUSIONS: Serum IgG4 ≥70 mg/dL in PSC predicts a shorter time to cirrhosis decompensation and LT.
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A human betaretrovirus (HBRV) has been linked with the autoimmune liver disease, primary biliary cholangitis (PBC), and various cancers, including breast cancer and lymphoma. HBRV is closely related to the mouse mammary tumor virus, and represents the only exogenous betaretrovirus characterized in humans to date. Evidence of infection in patients with PBC has been demonstrated through the identification of proviral integration sites in lymphoid tissue, the major reservoir of infection, as well as biliary epithelium, which is the site of the disease process. Accordingly, we tested the hypothesis that patients with PBC harbor a transmissible betaretrovirus by co-cultivation of PBC patients' lymph node homogenates with the HS578T breast cancer line. Because of the low level of HBRV replication, betaretrovirus producing cells were subcloned to optimize viral isolation and production. Evidence of infection was provided by electron microscopy, RT-PCR, in situ hybridization, cloning of the HBRV proviral genome and demonstration of more than 3400 integration sites. Further evidence of viral transmissibility was demonstrated by infection of biliary epithelial cells. While HBRV did not show a preference for integration proximal to specific genomic features, analyses of common insertion sites revealed evidence of integration proximal to cancer associated genes. These studies demonstrate the isolation of HBRV with features similar to mouse mammary tumor virus and confirm that patients with PBC display evidence of a transmissible viral infection.
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Betaretrovirus , Neoplasias de la Mama , Cirrosis Hepática Biliar , Animales , Femenino , Humanos , Cirrosis Hepática Biliar/etiología , Virus del Tumor Mamario del Ratón/genética , Ratones , Provirus/genéticaRESUMEN
We previously characterized a human betaretrovirus and linked infection with the development of primary biliary cholangitis (PBC). There are in vitro and in vivo data demonstrating that antiretroviral therapy used to treat human immunodeficiency virus (HIV) can be repurposed to treat betaretroviruses. As such, PBC patients have been treated with nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), alone and in combination with a boosted protease inhibitor or an integrase strand transfer inhibitor in case studies and clinical trials. However, a randomized controlled trial using combination antiretroviral therapy with lopinavir was terminated early because 70% of PBC patients discontinued therapy because of gastrointestinal side effects. In the open-label extension, patients tolerating combination therapy underwent a significant reduction in serum liver parameters, whereas those on NRTIs alone rebounded to baseline. Herein, we compare clinical experience in the experimental use of antiretroviral agents in patients with PBC with the broader experience of using these agents in people living with HIV infection. While the incidence of gastrointestinal side effects in the PBC population appears somewhat increased compared to those with HIV infection, the clinical improvement observed in patients with PBC suggests that further studies using the newer and better tolerated antiretroviral agents are warranted.
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Fármacos Anti-VIH , Betaretrovirus , Infecciones por VIH , Inhibidores de la Proteasa del VIH , Cirrosis Hepática Biliar , Malus , Fármacos Anti-VIH/efectos adversos , Antirretrovirales/efectos adversos , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Humanos , Cirrosis Hepática Biliar/tratamiento farmacológico , Lopinavir/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Inhibidores de la Transcriptasa Inversa/uso terapéuticoRESUMEN
Mass spectrometry-based shotgun glycomics (MS-SG) is a rapid, sensitive, label-, and immobilization-free approach for the discovery of natural ligands of glycan-binding proteins (GBPs). To perform MS-SG, natural libraries of glycans derived from glycoconjugates in cells or tissues are screened against a target GBP using catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS). Because glycan concentrations are challenging to determine, ligand affinities cannot be directly measured. In principle, relative affinities can be ranked by combining CaR-ESI-MS data with relative concentrations established by hydrophilic interaction liquid chromatography (HILIC) performed on the fluorophore-labeled glycan library. To validate this approach, as well as the feasibility of performing CaR-ESI-MS directly on labeled glycans, libraries of labeled N-glycans extracted from the human monocytic U937 cells or intestinal tissues were labeled with 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA), or procainamide (proA). The libraries were screened against plant and human GBPs with known specificities for α2-3- and α2-6-linked sialosides and quantified by HILIC. Dramatic differences, in some cases, were found for affinity rankings obtained with libraries labeled with different fluorophores, as well as those produced using the combined unlabeled/labeled library approach. The origin of these differences could be explained by differential glycan labeling efficiencies, the impact of specific labels on glycan affinities for the GBPs, and the relative efficiency of release of ligands from GBPs in CaR-ESI-MS. Overall, the results of this study suggest that the 2-AB(CaR-ESI-MS)/2-AB(HILIC) combination provides the most reliable description of the binding specificities of GBPs for N-glycans and is recommended for MS-SG applications.
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Glicómica , Espectrometría de Masa por Ionización de Electrospray , Proteínas Portadoras/metabolismo , Cromatografía Liquida , Colorantes Fluorescentes/química , Glicómica/métodos , Humanos , Ligandos , Polisacáridos/química , Proteínas/metabolismo , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
BACKGROUND AND AIMS: We investigated associations between ethnicity, survival, and disease severity in a diverse Canadian cohort of patients with primary biliary cholangitis (PBC). APPROACH AND RESULTS: Patients with PBC were included from the Canadian Network for Autoimmune Liver Disease. Ethnicity was defined using a modified list adopted from Statistics Canada, and ethnicities with small samples were grouped. Clinical events were defined as liver decompensation, HCC, liver transplantation, or death. Clinical event-free and liver transplantation-free survival were analyzed using Cox regression. Trajectories of serum liver function tests were assessed over time using mixed-effects regression. Health-related quality of life was assessed using the Short Form 36, the PBC-40 questionnaire, and the 5-D Itch scale and analyzed using mixed-effects regression. The cohort included 1538 patients with PBC from six sites and was comprised of 82% White, 4.7% Indigenous, 5.5% East Asian, 2.6% South Asian, and 5.1% miscellaneous ethnicities. Indigenous patients were the only ethnic group with impaired liver transplant-free and event-free survival compared to White patients (HR, 3.66; 95% CI, 2.23-6.01; HR, 3.09; 95% CI, 1.94-4.92). Indigenous patients were more likely to have a clinical event before diagnosis (10%) than all other ethnic groups despite similar age at diagnosis. Indigenous patients presented with higher alkaline phosphatase, total bilirubin, and GLOBE scores than White patients; and these relative elevations persisted during follow-up. CONCLUSIONS: Indigenous Canadians with PBC present with advanced disease and have worse long-term outcomes compared to White patients.
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Carcinoma Hepatocelular , Colangitis , Cirrosis Hepática Biliar , Neoplasias Hepáticas , Canadá/epidemiología , Etnicidad , Humanos , Calidad de Vida , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Ácido UrsodesoxicólicoRESUMEN
Shotgun metagenomics studies have improved our understanding of microbial population dynamics and have revealed significant contributions of microbes to gut homeostasis. They also allow in silico inference of the metagenome. While they link the microbiome with metabolic abnormalities associated with disease phenotypes, they do not capture microbial gene expression patterns that occur in response to the multitude of stimuli that constantly ambush the gut environment. Metatranscriptomics closes that gap, but its implementation is more expensive and tedious. We assessed the metabolic perturbations associated with gut inflammation using shotgun metagenomics and metatranscriptomics. Shotgun metagenomics detected changes in abundance of bacterial taxa known to be SCFA producers, which favors gut homeostasis. Bacteria in the phylum Firmicutes were found at decreased abundance, while those in phyla Bacteroidetes and Proteobacteria were found at increased abundance. Surprisingly, inferring the coding capacity of the microbiome from shotgun metagenomics data did not result in any statistically significant difference, suggesting functional redundancy in the microbiome or poor resolution of shotgun metagenomics data to profile bacterial pathways, especially when sequencing is not very deep. Obviously, the ability of metatranscriptomics libraries to detect transcripts expressed at basal (or simply low) levels is also dependent on sequencing depth. Nevertheless, metatranscriptomics informed about contrasting roles of bacteria during inflammation. Functions involved in nutrient transport, immune suppression and regulation of tissue damage were dramatically upregulated, perhaps contributed by homeostasis-promoting bacteria. Functions ostensibly increasing bacteria pathogenesis were also found upregulated, perhaps as a consequence of increased abundance of Proteobacteria. Bacterial protein synthesis appeared downregulated. In summary, shotgun metagenomics was useful to profile bacterial population composition and taxa relative abundance, but did not inform about differential gene content associated with inflammation. Metatranscriptomics was more robust for capturing bacterial metabolism in real time. Although both approaches are complementary, it is often not possible to apply them in parallel. We hope our data will help researchers to decide which approach is more appropriate for the study of different aspects of the microbiome.
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Emerging evidence suggests that host glycans influence severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we reveal that the receptor-binding domain (RBD) of the spike (S) protein on SARS-CoV-2 recognizes oligosaccharides containing sialic acid (Sia), with preference for monosialylated gangliosides. Gangliosides embedded within an artificial membrane also bind to the RBD. The monomeric affinities (Kd = 100-200 µM) of gangliosides for the RBD are similar to another negatively charged glycan ligand of the RBD proposed as a viral co-receptor, heparan sulfate (HS) dp2-dp6 oligosaccharides. RBD binding and infection of SARS-CoV-2 pseudotyped lentivirus to angiotensin-converting enzyme 2 (ACE2)-expressing cells is decreased following depletion of cell surface Sia levels using three approaches: sialyltransferase (ST) inhibition, genetic knockout of Sia biosynthesis, or neuraminidase treatment. These effects on RBD binding and both pseudotyped and authentic SARS-CoV-2 viral entry are recapitulated with pharmacological or genetic disruption of glycolipid biosynthesis. Together, these results suggest that sialylated glycans, specifically glycolipids, facilitate viral entry of SARS-CoV-2.
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Glucolípidos/metabolismo , SARS-CoV-2/metabolismo , Ácidos Siálicos/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Sitios de Unión , HumanosRESUMEN
Recurrent primary biliary cholangitis (rPBC) is frequent following liver transplantation and associated with increased morbidity and mortality. It has been argued that rPBC behaves like an infectious disease because more potent immunosuppression with tacrolimus is associated with earlier and more severe recurrence. Prophylactic ursodeoxycholic acid is an established therapeutic option to prevent rPBC, whereas the role of second line therapies, such as obeticholic acid and bezafibrate in rPBC, remains largely unexplored. To address the hypothesis that a human betaretrovirus plays a role in the development of PBC, we have tested antiretroviral therapy in vitro and conducted randomised controlled trials showing improvements in hepatic biochemistry. Herein, we describe the utility of combination antiretroviral therapy to manage rPBC in two patients treated with open label tenofovir/emtricitabine-based regimens in combination with either lopinavir or raltegravir. Both patients experienced sustained biochemical and histological improvement with treatment, but the antiretroviral therapy was associated with side effects.
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Colangitis , Infecciones por VIH , Cirrosis Hepática Biliar , Trasplante de Hígado , Antirretrovirales/uso terapéutico , Colangitis/tratamiento farmacológico , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Humanos , Cirrosis Hepática Biliar/tratamiento farmacológico , Ácido Ursodesoxicólico/uso terapéuticoRESUMEN
BACKGROUND & AIMS: Gamma-glutamyltransferase (GGT) is a serum marker of cholestasis. We investigated whether serum level of GGT is a prognostic marker for patients with primary biliary cholangitis (PBC). METHODS: We analyzed data from patients with PBC from the Global PBC Study Group, comprising 14 centers in Europe and North America. We obtained measurements of serum GGT at baseline and time points after treatment. We used Cox model hazard ratios to evaluate the association between GGT and clinical outcomes, including liver transplantation and liver-related death. RESULTS: Of the 2129 patients included in our analysis, 281 (13%) had a liver-related clinical endpoint. Mean age at diagnosis was 53 years and 91% of patients were female patients. We found a correlation between serum levels of GGT and alkaline phosphatase (ALP) (r = 0.71). Based on data collected at baseline and yearly for up to 5 years, higher serum levels of GGT were associated with lower hazard for transplant-free survival. Serum level of GGT at 12 months after treatment higher than 3.2-fold the upper limit of normal (ULN) identified patients who required liver transplantation or with liver-related death at 10 years with an area under the receiver operating characteristic curve of 0.70. The risk of liver transplantation or liver-related death in patients with serum level of GGT above 3.2-fold the ULN, despite level of ALP lower than 1.5-fold the ULN, was higher compared to patients with level of GGT lower than 3.2-fold the ULN and level of ALP lower than 1.5-fold the ULN (P < .05). Including information on level of GGT increased the prognostic value of the Globe score. CONCLUSIONS: Serum level of GGT can be used to identify patients with PBC at risk for liver transplantation or death, and increase the prognostic value of ALP measurement. Our findings support the use of GGT as primary clinical endpoint in clinical trials. In patients with low serum level of ALP, a high level of GGT identifies those who might require treatment of metabolic disorders or PBC treatment escalation.