The effect of ursodeoxycholic acid therapy on the natural course of primary biliary cirrhosis

The relationship between CXCR6+CD8+T cells and clinicopathological parameters in patients with primary biliary cholangitis

BACKGROUND

CXCR6+CD8+T cells have been implicated in the pathogenesis of various liver and autoimmune diseases. However, their involvement in primary biliary cholangitis (PBC) has not been elucidated.

METHODS

We used immunohistochemistry and flow cytometry to quantify CXCR6+CD8+T cells in hepatic tissue and peripheral blood samples obtained from CXCR6+CD8+T cells obtained from PBC patients. Then, we performed comprehensive statistical analyses to access the correlation between the abundance of these cells and clinical as well as pathological data across different stages of PBC.

RESULTS

Our research revealed that CXCR6+ cell frequencies in CD3+CD8+T cells from PBC patients significantly exceeded that of healthy controls (HCs) (2.24 vs. 0.61%, p < 0.01). A similar pattern emerged for hepatic CXCR6+CD8+T cell counts, which were notably higher in the PBC cohort compared to HCs. Our cohort consisted of 118 PBC patients, categorized into 62 early-stage (E-PBC) and 56 late-stage (L-PBC) cases. Notably, significant disparities existed between these groups in terms of liver enzyme and lipid profile levels (p < 0.05), with no notable differences observed in gender, age, blood counts, cholesterol levels, or autoantibodies (p > 0.05). Intriguingly, the quantity of hepatic CXCR6+CD8+T cells per high power field (HPF) was significantly elevated in both E-PBC and L-PBC patients as opposed to normal liver samples, indicating a substantial increase in these cells across all stages of PBC (p = 0.000). Spearman's rank correlation analysis showed a positive correlation between CXCR6+CD8+T cell counts and serum levels of Alkaline Phosphatase (AKP) and Gamma-Glutamyl Transferase (GGT), ANA, IgG and IgM, while revealing a negligible correlation with Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST). Subsequent findings indicated significant variances in CXCR6+ cell numbers not only among different PBC stages but also across various degrees of inflammation and fibrosis (p ≤ 0.007). In a follow-up study post-Ursodeoxycholic Acid (UDCA) treatment, stark differences were identified in biochemical and immunohistochemical profiles between responder (31 patients) and non-responder (33 patients) groups (p < 0.05). A Wilcoxon rank-sum test further demonstrated a significant difference in the level of hepatic CXCR6+CD8+T cells between these two response groups (p = 0.002).

CONCLUSION

CXCR6+CD8+T cells play a vital role in the pathogenesis of PBC, exhibiting correlations with the extent of inflammation, staging of liver fibrosis, and response to pharmacological interventions in PBC patients.

Prognostic scores in primary biliary cholangitis

Aim: Evaluating prognostic scores' utility in predicting ursodeoxycholic acid (UDCA) biochemical response (BR) and long-term liver-related complications in primary biliary cholangitis (PBC) patients. Patients & methods: This retrospective single-center study included 50 predominantly female PBC patients (median age: 56) on UDCA treatment. BR was defined by Paris II criteria. Liver-related complications during a median 76-month follow-up were assessed. APRI, ALBI, Mayo, GLOBE and UK-PBC scores were calculated. Results: 64% achieved BR, while 40% experienced liver-related complications. All scores showed good BR prediction (concordance statistics: 0.76-0.94) and excellent negative predictive values for 5-year liver complications (concordance statistics: 0.73-0.89). Conclusion: Implementing these scores in clinical practice is encouraged due to their effectiveness in predicting BR- and liver-related events.

MGAT5/TMEM163 variant is associated with prognosis in ursodeoxycholic acid-treated patients with primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic immune-mediated liver disease. Previous genome-wide meta-analysis has identified the association between variants in TMEM163 with PBC. Here we aimed to evaluate the association between variants near the reported risk loci of TMEM163 at 2q21.3 and prognosis of PBC patients.

METHODS

We performed a retrospective analysis of 347 PBC patients treated with ursodeoxycholic acid (UDCA) for at least 1 year. We collected clinical data at diagnosis and 1 year after UDCA treatment. SNPs within 200 kb upstream and downstream of the lead variant were genotyped and screened.

RESULTS

We identified that rs661899 near MGAT5 and TMEM163 showed the strongest association with prognosis in PBC patients. Patients carrying the rs661899 T allele tended to respond incompletely to UDCA treatment and had worse performances in laboratory values including aspartate aminotransferase (53.5 vs 32 vs 28.5 U/L, p = 0.001), alkaline phosphate (157.25 vs 125 vs 113 U/L, p = 0.001), albumin (41.5 vs 42.3 vs 43.7 g/L, p = 0.008) and bilirubin (19.2 vs 14.9 vs 12.85 μmol/L, p = 0.001). GLOBE scores (p = 4.8 × 10-5) and UK-PBC risk scores (p = 4.6 × 10-4) were strongly correlated with rs661899 genotype. Patients with TT genotype had a higher risk for adverse events compared with CC genotype (p = 0.039) during the 1-year follow-up. Results were also verified in an independent cohort.

CONCLUSIONS

PBC patients carrying the rs661899 T allele are associated with poor prognosis and adverse outcomes after 1-year UDCA therapy.

NOTCH signalling - a core regulator of bile duct disease?

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

Response to Ursodeoxycholic Acid May Be Assessed Earlier to Allow Second-Line Therapy in Patients with Unresponsive Primary Biliary Cholangitis

BACKGROUND

Response to ursodeoxycholic acid (UDCA) in primary biliary cholangitis (PBC) has been traditionally assessed 1 to 2 years after treatment initiation. With the development of new drugs, some patients may benefit from an earlier introduction of second-line therapies.

AIMS

This study aims to identify whether well-validated response criteria could correctly identify individuals likely to benefit from add-on second-line therapy at 6 months.

METHODS

Analysis of a multicenter retrospective cohort which included only patients with clear-cut PBC.

RESULTS

206 patients with PBC (96.6% women; mean age 54 ± 12 years) were included. Kappa concordance was substantial for Toronto (0.67), Rotterdam (0.65), Paris 1 (0.63) and 2 (0.63) criteria at 6 and 12 months, whereas Barcelona (0.47) and POISE trial (0.59) criteria exhibited moderate agreement. Non-response rates to UDCA was not statistically different when assessed either at 6 or 12 months using Toronto, Rotterdam or Paris 2 criteria. Those differences were even smaller or absent in those subjects with advanced PBC. Mean baseline alkaline phosphatase was 2.73 ± 1.95 times the upper limit of normal (× ULN) among responders versus 5.05 ± 3.08 × ULN in non-responders (p < 0.001).

CONCLUSIONS

After 6 months of treatment with UDCA, the absence of response by different criteria could properly identify patients who could benefit from early addition of second-line therapies, especially in patients with advanced disease or high baseline liver enzymes levels.

PPAR agonists for the treatment of primary biliary cholangitis: Old and new tales

Introduction

Primary biliary cholangitis (PBC) is an autoimmune liver disease involving the small intrahepatic bile ducts; when untreated or undertreated, it may evolve to liver fibrosis and cirrhosis. Ursodeoxycholic Acid (UDCA) is the standard of care treatment, Obeticholic Acid (OCA) has been approved as second-line therapy for those non responder or intolerant to UDCA. However, due to moderate rate of UDCA-non responders and to warnings recently issued against OCA use in patients with cirrhosis, further therapies are needed.Areas covered. Deep investigations into the pathogenesis of PBC is leading to proposal of new therapeutic agents, among which peroxisome proliferator-activated receptor (PPAR) ligands seem to be highly promising given the preliminary, positive results in Phase 2 and 3 trials. Bezafibrate, the most evaluated, is currently used in clinical practice in combination with UDCA in referral centers. We herein describe completed and ongoing trials involving PPAR agonists use in PBC, analyzing pits and falls.

Expert opinion

Testing new therapeutic opportunities in PBC is challenging due to its low prevalence and slow progression. However, new drugs including PPAR agonists, are currently under investigation and should be considered for at-risk PBC patients.

Autoantibodies in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic immune-mediated liver disease characterized by a lymphocytic cholangitis, with subsequent cholestasis, progressive liver fibrosis, and ultimately complications arising from end-stage liver disease. Testing for autoantibodies is important in the diagnosis of PBC, as well as stratifying prognosis. This review focuses on the role of autoantibodies in the diagnosis of PBC, as well as the relationship between autoantibodies with pathophysiology and prognostication, along with a discussion regarding novel and other related disease autoantibodies.

The prognostic value of antibodies to gp210 among patients with primary biliary cholangitis in Northeast China

BACKGROUND

Whether the anti-gp210 antibody can be used as a biomarker in patients with primary biliary cholangitis (PBC) remains controversial.

AIMS

We aimed to investigate the association between anti-gp210 antibodies and prognosis in ursodeoxycholic acid (UDCA)-treated PBC patients.

METHODS

We conducted a retrospective cohort study of 180 UDCA-treated PBC patients to assess the prognostic value of anti-gp210 antibodies using the Kaplan-Meier method and Cox proportional hazard regression analysis.

RESULTS

Of the patients included in our analysis, 50 (27.8%) were anti-gp210 positive, and 130 (72.2%) were anti-gp210 negative. The incidence of liver-related death or transplantation was more common in the anti-gp210 + group (22.0 vs. 9.2%, P=0.022). The five-year transplant-free survival rates of anti-gp210-positive patients vs. anti-gp210-negative patients were 77.0% and 90.3%, respectively. We found that the probability of transplant-free survival was significantly lower in the anti-gp210-positive patients than in the anti-gp210-negative patients (log-rank P=0.004). After adjusting for potential confounders using multivariable Cox regression model, positivity for anti-gp210 antibody (hazard ratio: 4.619, 95% confidence interval: 1.895-11.261, P=0.001) was found to be independently associated with an increase in liver-related mortality or transplantation.

CONCLUSION

In this cohort of UDCA-treated PBC patients, positivity for anti-gp210 antibody was independently associated with a higher risk of liver-related death or transplantation.

Recent advances on FXR-targeting therapeutics

The bile acid receptor FXR has emerged as a bona fide drug target for chronic cholestatic and metabolic liver diseases, ahead of all non-alcoholic fatty liver disease (NAFLD). FXR is highly expressed in the liver and intestine and activation at both sites differentially contributes to its desired metabolic effects. Unrestricted FXR activation, however, also comes along with undesired effects such as a pro-atherogenic lipid profile, pruritus and hepatocellular toxicity under certain conditions. Several pre-clinical studies have confirmed the potency of FXR activation for cholestatic and metabolic liver diseases, but overall it remains still open whether selective activation of intestinal FXR is advantageous over pan-FXR activation and whether restricted or modulated FXR activation can limit some of the side effects. Even more, FXR antagonist also bear the potential as intestinal-selective drugs in NAFLD models. In this review we will discuss the molecular prerequisites for FXR activation, pan-FXR activation and intestinal FXR in/activation from a therapeutic point of view, different steroidal and non-steroidal FXR agonists, ways to restrict FXR activation and finally what we have learned from pre-clinical models and clinical trials with different FXR therapeutics.

Downregulation of Programmed Death-1 Pathway Promoting CD8 + T Cell Cytotoxicity in Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune disease. CD8 + T cell (CTLs) cytotoxicity played a crucial rule in of PBC with unclear detailed pathogenesis.

AIMS

The role of the programmed death-1 (PD-1) pathway in CD8 + T cell cytotoxicity in patients with PBC was determined.

METHODS

We recruited 69 patients with PBC and 57 healthy controls (HCs). PD-1 pathway in peripheral CD8 + T cells and related cytokines were detected, and gene expression levels were detected. Immunofluorescence staining of PD-1/PD-L1 was performed on liver tissue. PD-1 ± CTLs were cocultured with human intrahepatic biliary epithelial cells (HiBECs) to measure CTL cytotoxicity, proliferation and cytokine levels and HiBEC apoptosis. The upstream signaling pathway of PD-1 was detected.

RESULTS

PBC patients exhibited Tbet gene upregulation and PD-1 downregulation in CTLs, with PD-1 expression reduced in CTLs and PD-L1 reduced in the liver portal region relative to HCs. Higher plasma IL-10, interferon-γ and transforming growth factor-β concentrations were observed in the PBC group than the HC group. In CTL and HiBEC coculture experiment, compared with PD-1- CTLs, PD-1 + CTLs exhibited weaker cytotoxicity, less proliferation and lower cytokine production. When the system was blocked by anti-PD-1 antibodies, these effects were antagonized.

CONCLUSIONS

PD-1 expression in CD8 + T cells decreased, and PD-1 pathway-related cytokines changed in patients with PBC. PD-1/PD-L1 pathway silencing increased CD8 + T cell proliferation, related cytokine production and CTL cytotoxic effects on HiBECs in coculture experiment. The PD-1/PD-L1 pathway might represent an important pathway in the immunological mechanism underlying PBC.

The impact of undiagnosed primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic autoimmune disease characterized by symptoms with a major impact on the quality of life. The aim of this study was to identify patients with undiagnosed PBC who are not under hepatology follow-up and to assess the clinical impact of lack of adequate treatment and surveillance.

METHODS

Adult patients with a positive antimitochondrial antibodies (AMA) titer were identified from local biochemistry records. Patients with probable PBC who were not known by the hepatology services were invited to accurately stage their disease and optimize medical management.

RESULTS

A total of 214 AMA-positive patients were identified, 148 of whom had diagnostic criteria for PBC. Twenty-three patients were not known by the hepatology services, most of them followed by specialties other than gastroenterology. These patients had significantly higher liver stiffness compared to those followed by the hepatology services (14.3 kPa vs. 6.2 kPa; P = 0.009). A large percentage of untreated individuals reported fatigue (72.7%) and pruritus (27.3%).

CONCLUSIONS

A substantial number of patients with PBC are not known to have hepatology services with a significant long-term impact from a lack of follow-up and therapy. Strategies must be established to identify these patients and reduce the disease's progressive nature.

Antibody-Mediated Rejection and Recurrent Primary Disease: Two Main Obstacles in Abdominal Kidney, Liver, and Pancreas Transplants

The advances in acute phase care have firmly established the practice of organ transplantation in the last several decades. Then, the next issues that loom large in the field of transplantation include antibody-mediated rejection (ABMR) and recurrent primary disease. Acute ABMR is a daunting hurdle in the performance of organ transplantation. The recent progress in desensitization and preoperative monitoring of donor-specific antibodies enables us to increase positive outcomes. However, chronic active ABMR is one of the most significant problems we currently face. On the other hand, recurrent primary disease is problematic for many recipients. Notably, some recipients, unfortunately, lost their vital organs due to this recurrence. Although some progress has been achieved in these two areas, many other factors remain largely obscure. In this review, these two topics will be discussed in light of recent discoveries.

Definition and Management of Patients With Primary Biliary Cholangitis and an Incomplete Response to Therapy

Primary biliary cholangitis (PBC) is an immune-mediated chronic liver disease characterized by biliary epithelial injury, cholestasis, and progressive fibrosis that can lead to cirrhosis and requirement for liver transplantation. All patients with PBC should receive initial treatment with ursodeoxycholic acid (UDCA), and odds for response are based on characteristics at baseline. It is important to have clear definitions of patients at risk for a poor response to therapy, of biochemical markers of an incomplete response, and standardized management. Patients typically are assessed after 12 months of treatment with UDCA for biochemical markers of response. However, evaluation at 6 months has been proposed for patients with more severe disease or symptoms (such as pruritus or fatigue). Markers of response to therapy include reduced serum levels of alkaline phosphatase and bilirubin (Paris-2, Toronto, GLOBE, and so forth); patients with high levels of total and conjugated bilirubin or levels of alkaline phosphatase more than 1.5-fold the upper limit of normal should be considered for second-line therapy. Patients with adequate biochemical responses can continue UDCA monotherapy. Incomplete responders should be considered for second-line therapies with obeticholic acid (licensed) or fibrates (unlicensed) in addition to continued treatment with UDCA. Patients with PBC should be followed up for life.

Liver stiffness measurements by 2-dimensional shear wave elastography compared to histological and ultrasound parameters in primary biliary cholangitis

BACKGROUND AND AIMS

Liver stiffness measurements (LSMs) by 2-dimensional-shear-wave elastography (LSM_2D-SWE) are now widely used in hepatology. However, relevant information for primary biliary cholangitis (PBC) is scant. We compare LSM_2D-SWE with liver biopsy (LB) in a cohort of PBC patients in Greece.

METHODS

Data of 68 LBs from 53 PBC patients were retrospectively analyzed and fibrosis stage was compared to LSM_2D-SWE. Forty-six patients (86.8%) were females and at the time of LBx median (IQR) age was 62.6 (53.2-72.1). Demographic, UDCA treatment, histological and B-mode ultrasound data were tested for their influence on LSM_2D-SWE estimates.

RESULTS

Liver fibrosis stages F0-F4 were found in 4, 19, 19, 16 and 10 cases, respectively. Across stages F0-F4, the LSM_2D-SWE was 5.6 (5.1-6.1), 7.0 (5.8-7.7), 9.1 (7.3-11.5), 10.8 (9.9-12.2) and 14.5 (11.9-25.7) kPa, respectively, with highly significant difference (p<.001). The LSM_2D-SWE differed also significantly between F0 vs. F1 (p=.027), F1 vs. F2 (p=.005) and F3 vs. F4 (p=.017). The discriminatory ability of LSM_2D-SWE for mild, significant, severe fibrosis and cirrhosis was highly significant in all comparisons (p<.001), with AUC_2D-SWE 95.3%, 87.4%, 85.3% and 95.3% and accuracy 89.7%, 85.3%, 80.9% and 86.8%, respectively. Among 21 parameters tested, significant predictors of LSM_2D-SWE by multiple linear regression were fibrosis stage, portal inflammation and parenchymal heterogeneity. The portal inflammation grade accounted for 32.2% of LSM variation with adjusted R² 0.428.

CONCLUSIONS

In patients with PBC, LSM measurements by 2D-SWE can reliably discriminate between mild, significant, severe fibrosis and cirrhosis. Measurements are significantly affected by portal inflammation grade.

Primary Biliary Cholangitis: Predictors of Poor Response to Ursodeoxycholic Acid after 1 Year of Treatment in Moroccan Patients

Introduction: Primary biliary cholangitis (PBC), the new dominance of primary biliary cirrhosis, is a cholestatic disease of autoimmune etiology and represents the leading cause of intra-hepatic cholestasis. Treatment is mainly based on ursodeoxycholic acid. The biological response to treatment is the main predictor of survival without liver transplantation. The Globe-score has been recently validated as the main prognostic factor. Materials and methods: This is a retrospective study carried out in our department collating all cases of PBC followed in consultation. The aim of our work is to research the predictors of poor response to UDCA. Results: 46 patients were collected. The mean age of the patients was 58.82 years, with a predominance of women (n = 43, 93.5%). 34.78% of patients were in the stage of cirrhosis. Anti-M2 mitochondria antibodies were positive in 44 patients (95.65%). An overlap syndrome was found in 11 patients (23.9%). Treatment was based on UDCA combined with corticosteroid therapy and immunosuppressant for overlap syndrome. A biochemical response at 1 year of treatment according to the Paris II criteria was found in 47.8%. The average value of the globe score was 1.35. A score greater than 0.30 was objectified in 20 cases (43.47%). Nineteen cirrhotic patients (41.30%) had a globe score> 0.30. Factors associated with poor response to therapy were: stage of decompensated cirrhosis, elevated pre-therapy total bilirubin greater than 30 g / l and hypoalbunemia less than 35 g / l. The study of the correlation between Globe score and Paris II showed a strong and significant association with a correlation coefficient estimated at 67%. The Paris II score was significantly correlated with the response to treatment (p = 0.001). Conclusion: In accordance with the data in the literature, the globe-score and Paris II are two similar predictive means for evaluating the response at 1 year of treatment in Moroccan context. Keywords: Morocco, Predictors of response, Primary biliary cholangitis, Ursodeoxycholic acid

Ursodeoxycholic acid impairs liver-infiltrating T-cell chemotaxis through IFN-γ and CX3CL1 production in primary biliary cholangitis

Ursodeoxycholic acid (UDCA) is the primary treatment for primary biliary cholangitis (PBC), but its mechanism of action remains unclear. Studies suggest that UDCA enhances NF erythroid 2-related factor 2 (NFE2L2) expression and that the interaction between IFN-γ and C-X3-C motif chemokine ligand 1 (CX3CL1) facilitates biliary inflammation in PBC. Therefore, we examined the effects of UDCA on the expression of IFN-γ and CX3CL1 in in vitro and in vivo PBC models such as human liver tissue, a murine model, cell lines, and isolated human intrahepatic biliary epithelial cells (IHBECs). We observed a significant decrease in IFN-γ mRNA levels and positive correlations between IFN-γ and CX3CL1 mRNA levels post-UDCA treatment in PBC livers. NFE2L2-mediated transcriptional activation was significantly enhanced in UDCA-treated Jurkat cells. In 2-octynoic acid-immunized mice, IFN-γ production by liver-infiltrating T cells was dependent on NFE2L2 activation. IFN-γ significantly and dose-dependentlyinduced CX3CL1 expression, which was significantly decreased in HuCC-T1 cells and IHBECs upon UDCA treatment. These results suggest that UDCA-induced suppression of IFN-γ and CX3CL1 production attenuates the chemotactic and adhesive abilities of liver-infiltrating T cells in PBC.

Widespread gaps in the quality of care for primary biliary cholangitis in UK

OBJECTIVE

Primary biliary cholangitis (PBC) is a progressive, autoimmune, cholestatic liver disease affecting approximately 15 000 individuals in the UK. Updated guidelines for the management of PBC were published by The European Association for the Study of the Liver (EASL) in 2017. We report on the first national, pilot audit that assesses the quality of care and adherence to guidelines.

DESIGN

Data were collected from 11 National Health Service hospitals in England, Wales and Scotland between 2017 and 2020. Data on patient demographics, ursodeoxycholic acid (UDCA) dosing and key guideline recommendations were captured from medical records. Results from each hospital were evaluated for target achievement and underwent χ² analysis for variation in performance between trusts.

RESULTS

790 patients' medical records were reviewed. The data demonstrated that the majority of hospitals did not meet all of the recommended EASL standards. Standards with the lowest likelihood of being met were identified as optimal UDCA dosing, assessment of bone density and assessment of clinical symptoms (pruritus and fatigue). Significant variations in meeting these three standards were observed across UK, in addition to assessment of biochemical response to UDCA (all p<0.0001) and assessment of transplant eligibility in high-risk patients (p=0.0297).

CONCLUSION

Our findings identify a broad-based deficiency in 'real-world' PBC care, suggesting the need for an intervention to improve guideline adherence, ultimately improving patient outcomes. We developed the PBC Review tool and recommend its incorporation into clinical practice. As the first audit of its kind, it will be used to inform a future wide-scale reaudit.

Primary biliary cholangitis: pathogenic mechanisms

PURPOSE OF REVIEW

Primary biliary cholangitis (PBC) is characterized by autoimmune damage of intrahepatic bile ducts associated with a loss of tolerance to mitochondrial antigens. PBC etiopathogenesis is intriguing because of different perplexing features, namely: a) although mitochondria are present in all cell types and tissues, the damage is mainly restricted to biliary epithelial cells (BECs); b) despite being an autoimmune disorder, it does not respond to immunosuppressive drugs but rather to ursodeoxycholic acid, a bile salt that induces HCO3- rich choleresis; c) the overwhelming female preponderance of the disease remains unexplained. Here we present an etiopathogenic view of PBC which sheds light on these puzzling facts of the disease.

RECENT FINDINGS

PBC develops in patients with genetic predisposition to autoimmunity in whom epigenetic mechanisms silence the Cl-/HCO3- exchanger AE2 in both cholangiocytes and lymphoid cells. Defective AE2 function can produce BECs damage as a result of decreased biliary HCO3- secretion with disruption of the protective alkaline umbrella that normally prevents the penetration of toxic apolar bile salts into cholangiocytes. AE2 dysfunction also causes increased intracellular pH (pHi) in cholangiocytes, leading to the activation of soluble adenylyl cyclase, which sensitizes BECs to bile salt-induced apoptosis. Recently, mitophagy was found to be inhibited by cytosolic alkalization and stimulated by acidification. Accordingly, we propose that AE2 deficiency may disturb mitophagy in BECs, thus, promoting the accumulation of defective mitochondria, oxidative stress and presentation of mitochondrial antigens to the immune cells. As women possess a more acidic endolysosomal milieu than men, mitophagy might be more affected in women in an AE2-defective background. Apart from affecting BECs function, AE2 downregulation in lymphocytes may also contribute to alter immunoregulation facilitating autoreactive T-cell responses.

SUMMARY

PBC can be considered as a disorder of Cl-/HCO3- exchange in individuals with genetic predisposition to autoimmunity.

Changes in disease characteristics of primary biliary cholangitis: An observational retrospective study from 1982 to 2016

AIM

Disease characteristics of primary biliary cholangitis have changed recently. However, detailed studies on the subject have been limited. Therefore, we aimed to clarify disease characteristics of patients with recent primary biliary cholangitis using the cohort from Niigata University and 21 affiliated hospitals.

METHODS

Overall, 508 patients were enrolled in this study from 1982 to 2016, divided into three cohorts according to their year of diagnosis: ≤1999, 2000-2009 and ≥2010. We compared differences in clinical characteristics, response to ursodeoxycholic acid and prognosis.

RESULTS

The male-to-female ratio increased incrementally from 1:16.4 (≤1999) to 1:3.8 (≥2010) (P < 0.001). In women, the median age at diagnosis increased incrementally from 54.0 years (≤1999) to 60.5 years (≥2010) (P < 0.001) and serum albumin decreased gradually (P = 0.001), which might have affected the increase in the Fibrosis-4 Index and albumin-bilirubin score. The ursodeoxycholic acid response rate according to the Barcelona criteria increased incrementally from 26.7% (≤1999) to 78.4% (≥2010) (P < 0.010), and those according to other criteria (Paris-I, Rotterdam and Toronto) were approximately ≥80% in all cohorts. Ten-year survival rate in the ≤1999 and 2000-2009 cohorts were 98.6% and 95.6%, respectively. These earlier cohorts were also characterized by a higher rate of asymptomatic state and mild histology (83.5% [≤1999] and 84.7% [2000-2009], and 93.6% [≤1999] and 91.1% [2000-2009]).

CONCLUSIONS

Patients with primary biliary cholangitis were characterized by older age at diagnosis and an increase in male to female ratio as well as higher response rates of ursodeoxycholic acid and longer survival, resulting from the early recognition of primary biliary cholangitis.

Ursodesoxycholic acid alleviates liver fibrosis via proregeneration by activation of the ID1-WNT2/HGF signaling pathway

BACKGROUND

The human liver possesses a remarkable capacity for self-repair. However, liver fibrosis remains a serious medical concern, potentially progressing to end-stage liver cirrhosis and even death. Liver fibrosis is characterized by excess accumulation of extracellular matrix in response to chronic injury. Liver regenerative ability, a strong indicator of liver health, is important in resisting fibrosis. In this study, we provide evidence that ursodesoxycholic acid (UDCA) can alleviate liver fibrosis by promoting liver regeneration via activation of the ID1-WNT2/hepatocyte growth factor (HGF) pathway.

METHODS

Bile duct ligation (BDL) and partial hepatectomy (PH) mouse models were used to verify the effects of UDCA on liver fibrosis, regeneration, and the ID1-WNT2/HGF pathway. An Id1 knockdown mouse model was also used to assess the role of Id1 in UDCA alleviation of liver fibrosis.

RESULTS

Our results demonstrate that UDCA can alleviate liver fibrosis in the BDL mice and promote liver regeneration via the ID1-WNT2/HGF pathway in PH mice. In addition, Id1 knockdown abolished the protection afforded by UDCA in BDL mice.

CONCLUSIONS

We conclude that UDCA protects against liver fibrosis by proregeneration via activation of the ID1-WNT2/HGF pathway.

Response Rate and Impact on Lipid Profiles of Obeticholic Acid Treatment for Patients with Primary Biliary Cholangitis: A Meta-Analysis

BACKGROUND

Up to 40% of patients with primary biliary cholangitis (PBC) have an inadequate response to ursodeoxycholic acid (UDCA). Obeticholic acid (OCA) is considered the addition of treatment, but the response rate based on commonly referenced biochemical response criteria and lipids' impact was unclear. Previous studies reported inconsistency results partially due to small sample size. Therefore, we performed a meta-analysis and aimed to explore OCA treatment's response rate and effect on lipids' profiles in PBC patients.

METHODS

We performed PubMed, Embase, and Cochrane controlled trials register (updated to JUN 2019) databases and manual bibliographical searches for randomized controlled trials reporting on OCA treatment in PBC patients. Two researchers independently extracted data and assessed the risk of bias of studies. We calculated risk ratio (RR) for the overall complete response rate, and the standardized mean difference (SMD) for the serum lipids changes after OCA treatment, all with 95% confidence intervals (CIs) using fixed-effects models. We registered this meta-analysis with PROSPERO (registration number: CRD42020148550).

RESULTS

Three trials, with 265 patients, were selected for the analysis. OCA was superior to placebo in PBC patients (RR, 1.48; 95% CI, 1.15-1.90). OCA's pooled treatment response rate was 65% (95% CI, 56%-74%), corresponding to Paris I criteria. Besides, OCA significantly decreased total cholesterol (P=0.02) with no heterogeneity (P=0.87, I ² = 0%) and high-density lipoprotein levels (P < 0.05) with no heterogeneity (P=0.82, I ² = 0%).

CONCLUSIONS

This meta-analysis demonstrated that OCA was a promising additional treatment for PBC patients and might reduce serum cholesterol levels. The longer follow-up studies are needed to give more evidence.

The ursodeoxycholic acid response score predicts pathological features in primary biliary cholangitis

AIM

The ursodeoxycholic acid response score (URS) can predict the biochemical response to 12 months of ursodeoxycholic acid (UDCA) treatment in patients with primary biliary cholangitis (PBC). We investigated the relationship between the URS and the histopathological features before and after UDCA treatment.

METHODS

Patients with PBC (n = 126) were examined for the association between the probability of response (POR) to UDCA based on the URS formulas and clinicopathological features. Furthermore, 30 patients were examined for the association between the POR and pathological changes.

RESULTS

The POR area under the receiver operating characteristic curve (AUROC) for predicting the biochemical response to UDCA was 0.861. The PORs of stage 1 in the Nakanuma system and grade 0 in the CK7 grading in hepatocytes were significantly higher than those of stage 3 and grade 3, respectively. The AUROCs for the prediction of stage ≥2, stage ≥3 and stage 4 in the Nakanuma system at pretreatment were 0.592, 0.710 and 0.817, respectively. The AUROCs for the prediction of grade ≥1, grade ≥2 and grade 3 in the CK7 hepatocyte grading were 0.741, 0.824 and 0.970, respectively. Furthermore, the AUROC for predicting the histological stage progression after UDCA treatment in the Scheuer classification and the Nakanuma system were 0.712 and 0.799, respectively.

CONCLUSIONS

The URS not only predicts the biochemical response, but also reflects the Nakanuma system and the CK7 hepatocyte grading at pretreatment. This scoring system can identify an inadequate histological response to UDCA treatment in the Scheuer classification and the Nakanuma system.

The association of histological progression with biochemical response to ursodeoxycholic acid in primary biliary cholangitis

Primary biliary cholangitis (PBC) is currently diagnosed at an early stage; therefore, the number of patients with PBC without symptoms at the time of diagnosis is increasing. However, up to 30% of patients with PBC exhibit the suboptimal response to ursodeoxycholic acid (UDCA) and are at high risk of end-stage liver disease. Obeticholic acid is an approved second-line therapy for patients with PBC that are refractory to UDCA. Novel surrogate endpoints are required to identify individuals eligible for second-line therapies. An inadequate biochemical response to UDCA is a useful predictor of poor outcomes in patients with PBC. In addition to UDCA effects on biochemical parameters, histological outcomes could be considered as candidate surrogate endpoints. Alterations in liver histology are used as surrogate endpoints in clinical studies. However, current staging systems are insufficient to determine PBC disease severity and progression because of the pathological heterogeneity of the disease. Histological features at baseline and biochemical response to UDCA treatment can affect the disease course of PBC. Therefore, novel surrogate endpoints must be represented by parameters characterized by histological outcomes and treatment responses in PBC. In this review, we discuss the existing histological parameters and newly created factors to identify patients with PBC who are at a high risk of developing end-stage liver disease and, consequently, the potential need for additional treatments.

Cholestatic liver disease: Practice guidelines from the Saudi Association for the Study of Liver diseases and Transplantation

Cholestatic liver diseases (CLDs) are a group of diseases characterized by jaundice and cholestasis as the main presentation with different complications, which have considerable impact on the liver and can lead to end-stage liver disease, cirrhosis, and liver-related complications. In the last few years, tremendous progress has been made in understanding the pathophysiology, diagnosis, and treatment of patients with these conditions. However, several aspects related to the management of CLDs remain deficient and unclear. Due to the lack of recommendations that can help in the management, treatment of those conditions, the Saudi Association for the Study of Liver diseases and Transplantation (SASLT) has created a task force group to develop guidelines related to CLDs management in order to provide a standard of care for patients in need. These guidelines provide general guidance for health care professionals to optimize medical care for patients with CLDs for both adult and pediatric populations, in association with clinical judgments to be considered on a case-by-case basis. These guidelines describe common CLDs in Saudi Arabia, with recommendations on the best approach for diagnosis and management of different diseases based on the Grading of Recommendation Assessment (GRADE), combined with a level of evidence available in the literature.

Investigational drugs in early phase development for primary biliary cholangitis

Introduction: With a large percentage of patients having an incomplete response or intolerance to current FDA approved medications, new therapies for the treatment of primary biliary cholangitis are in great demand. Areas covered: In this review, we assess currently available drugs as well as promising new therapies for the treatment of primary biliary cholangitis. A literature search was performed with the following search terms: 'PBC treatment,' 'PBC therapeutics,' 'PBC clinical trials,' and included original articles, meta-analyses, and systematic reviews from 1 January 1981, to 1 January 2020. ClinicalTrials.gov was accessed for data from ongoing trials. Expert opinion: Targeted drug therapies offer an alternative for patients who are unable to meet their therapeutic goals with either of the two currently approved treatment options. Specifically, new drugs targeting bile-acid regulation, immune-modulation, and fibrogenic pathways are currently in development with multiple agents showing encouraging early results with the ultimate goal of developing therapies that will achieve high rates of biochemical remission, will be well tolerated, and improve symptoms and quality of life in patients with primary biliary cholangitis. Based on a review of the current literature, PPAR agonists appear to be promising agents, along with FGF19 analogs and FXR agonists.

Primary biliary cholangitis with normal alkaline phosphatase: A neglected clinical entity challenging current guidelines

BACKGROUND & AIM

The diagnosis of primary biliary cholangitis (PBC), an uncommon immune-mediated cholestatic liver disease, is based on positive circulating anti-mitochondrial (AMA) and/or PBC-specific anti-nuclear autoantibodies (ANA), coupled with elevated serum alkaline phopsphatase (ALP) levels. Timely initiation of treatment with ursodeoxycholic acid prevents progression to cirrhosis and liver failure. We aimed at investigating liver histology in patients with normal ALP level and positive AMA and/or PBC-specific ANA.

METHODS

We searched the Swiss PBC Cohort Study database, which includes subjects with positive PBC autoimmune serology and normal ALP levels, for patients who underwent a liver biopsy. Histological slides were centrally reviewed by an expert liver pathologist, and sera were centrally re-tested for AMA and ANA.

RESULTS

30 patients were included; 90% females, median age 53 (range 27-72) years. Twenty-four (80%) had liver histology typical for (n = 2), consistent with (n = 16) or suggestive of (n = 6) PBC, including three of four AMA-negative ANA-positive patients. Among 22 ursodeoxycholic acid treated patients, 14 had elevated GGT levels before treatment; a significant decrease of the median GGT level between pre- (1.46 x ULN) and post- (0.43 x ULN) treatment (p = 0.0018) was observed.

CONCLUSIONS

In our series, a high proportion of AMA positive patients with normal ALP levels have PBC. For the first time we show histological diagnosis of PBC in AMA-negative/PBC-specific ANA-positive subjects and the potential role of GGT as a biomarker in PBC patients with normal baseline ALP levels. Current guidelines for the diagnosis of PBC do not cover the whole extent of PBC presentation, with important clinical implications in terms of timely treatment initiation.

Treatment of primary biliary cholangitis with ursodeoxycholic acid, prednisolone and immunosuppressants in patients not responding to ursodeoxycholic acid alone and the prognostic indicators

BACKGROUND AND AIM

We reviewed the medical records of primary biliary cholangitis patients who were diagnosed by liver biopsy and treated with the corresponding treatment. We evaluated the therapeutic effect and long-term prognostic indicators.

METHODS

This observational cohort study enrolled 80 eligible patients diagnosed by liver biopsy between December 2013 and December 2018 in our department. UDCA monotherapy or UDCA added to prednisolone and immunosuppressant triple therapy was prescribed to patients. We analyzed and compared the demographic characteristics, biochemistry profiles, immune parameters, and noninvasive liver fibrosis assessments at baseline as well as the treatment efficacy, long-term outcomes and adverse effects at baseline and at each visit between the two groups. The indicators that could affect prognosis were assessed.

RESULTS

Thirty-eight primary biliary cholangitis patients received UDCA monotherapy (group A), and another 42 patients received UDCA, prednisolone and immunosuppressant triple therapy (group B). After therapy, all patients showed significant improvements in liver biochemical parameters, immune indicators, and noninvasive fibrosis indicators (Fibrosis-4 (FIB-4), aspartate aminotransferase-to-platelet ratio index (APRI)), all P values<0.0001. The Mayo score also decreased significantly after treatment (P=0.022). Triple therapy was more effective, and there was a significant difference between the two groups. In addition, multivariate analysis showed that anti-gp210 antibody positivity; antimitochondrial antibody (AMA) negativity; high alkaline phosphatase (ALP), total bilirubin (TBIL) and globulin levels; and a severe degree of fibrosis at baseline were independent predictors of a poor prognosis.

CONCLUSIONS

Triple therapy was a treatment option for UDCA-refractory PBC patients. Anti-gp210 antibody positivity; AMA negativity; high ALP, TBIL and globulin levels; and a severe degree of fibrosis at baseline were associated with a poor prognosis.

Association between serum ficolin-1 level and disease progression in primary biliary cholangitis

Pattern recognition molecules (PRMs) in the complement system contribute to homeostasis as mediators of complement activation. The contribution of PRMs to primary biliary cholangitis (PBC) is unknown. In the current study, we aimed to assess the association between PRMs and the clinical findings of PBC. A total of 122 PBC patients and 20 healthy controls were enrolled. We measured four different PRMs (mannose-binding lectin [MBL], ficolin-1, ficolin-2 and ficolin-3) using stored sera, and retrospectively analyzed the associations between PRMs and laboratory findings, histological findings, and the development of cirrhosis-related conditions. Ficolin-1 levels were significantly higher in the PBC patients than in the healthy controls (152 ng/mL vs 102 ng/mL, P = 0.034), but no significant differences were observed regarding MBL, ficolin-2, and ficolin-3 levels. Ficolin-1 was significantly correlated with alkaline phosphatase (ALP). Low ficolin-1 levels were significantly associated with the development of cirrhosis-related conditions independent for histological stage and ALP levels (hazard ratio: 0.933; 95% confidence interval: 0.875-0.994; P = 0.032). Patients with low levels of ficolin-1 (< 77 ng/mL) had a significantly increased rate of developing cirrhosis-related conditions. Low ficolin-1 levels were associated with disease progression independent of histological stage and ALP levels in patients with PBC.

A nomogram based on pretreatment clinical parameters for the prediction of inadequate biochemical response in primary biliary cholangitis

Background

Ursodeoxycholic acid (UDCA) has been widely recommended as the first‐line drug for primary biliary cholangitis (PBC) in the current guidelines. However, its therapeutic effects are poor in nearly one‐third of patients. The early identification and intervention of these patients is crucial for delaying disease progression. Therefore, we explored risk factors for inadequate biochemical response and constructed a nomogram to predict the potential risk.

Methods

We enrolled 356 patients and randomly divided them into training (70%) and validation groups (30%). We defined inadequate biochemical response as the study endpoint. Logistic analysis was used to identify the independent predictors of poor biochemical response. Based on these factors, a predictive nomogram was finally constructed. Then, discrimination and calibration were evaluated by internal validation. Additionally, the association between the model predictions and prognosis was further analyzed.

Results

Female sex, and albumin and bilirubin concentrations were identified as risk factors, and a nomogram was built based on these factors. The areas under the ROC curves of the training and validation groups were 0.809 and 0.791, respectively. Moreover, calibration curves showed that predictions of the nomogram had good concordance with the actual outcomes. The correlation analysis demonstrated that PBC patients with a high probability of a suboptimal biochemical response were more likely to have adverse outcomes.

Conclusion

We constructed a nomogram, which can accurately predict the risk of inadequate biochemical response to UDCA, facilitating the early screening of high‐risk patients with PBC who should be prioritized for additional therapy.

Efficacy of ursodeoxycholic acid combined with prednisolone and immunosuppressant triple therapy in the treatment of refractory primary biliary cholangitis

BACKGROUND AND AIM

To explore the efficacy treatment regimen in refractory PBC.

METHODS

Triple treatment including ursodeoxycholic acid, prednisolone and immunosuppressant was prescribed to 47 refractory patients. Biochemistries, immune parameters, non-invasive liver fibrosis assessments were measured during follow-up.

RESULTS

Triple therapy resulted in significant decrease in ALP, GGT, ALT, AST, TBIL, ALB, IgG, IgM, APRI, FIB-4 and S-INDEX. The biochemical cumulative normalization rates of ALP and other biochemical parameters were higher in long-term follow-up. Poor outcome was observed in patients with lower ALB, higher TBIL, PT, sp100 positivity and advanced liver pathology at baseline. Osteoporosis and bone fracture were observed in 15% patients.

CONCLUSIONS

Triple therapy is associated with marked decrease and normalization of ALP and other parameters. ALB, TBIL, PT, sp100 and pathology were related with poor outcome. Osteoporosis should be closely monitored.

Update on Emerging Treatment Options for Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease that may progress to fibrosis or cirrhosis. Treatment options are currently limited. Ursodeoxycholic acid (UDCA) remains first-line therapy and has been proven to normalize serum biochemistries, halt histologic disease progression, and lead to patient survival comparable to the general population. Obeticholic acid (OCA) was recently approved as adjunct therapy in PBC patients with inadequate response or intolerance to UDCA. However, OCA has been associated with worsening pruritus in clinical studies which may limit its use in this patient population. Several studies are currently underway to address the lack of treatment options for PBC. Of these, fibrates, which have been used in Japan for over a decade, have produced promising results. Furthermore, as currently approved therapies for PBC do not address the potentially debilitating clinical symptoms of PBC such as pruritus and fatigue, supplemental therapy is often required for symptom control.

IgM response is a prognostic biomarker of primary biliary cholangitis treated with ursodeoxycholic acid and bezafibrate

BACKGROUND AND AIM

Primary biliary cholangitis (PBC) patients who are refractory to ursodeoxycholic acid (UDCA) are at risk for progression to cirrhosis and liver failure. Bezafibrate could be an alternative second-line therapeutic option in these patients. This study aimed to evaluate the long-term outcome(s) of combined UDCA and bezafibrate therapy in UDCA-refractory PBC patients and identify prognostic factors.

METHODS

Among 445 patients treated with UDCA, 150 patients inadequately responded to UDCA monotherapy and received long-term UDCA plus bezafibrate (median, 15 years). Data from these patients were used for this retrospective analysis.

RESULTS

Combination therapy resulted in significant improvements in serum biochemistry and liver transplantation risk estimated using the UK-PBC-risk and the GLOBE scores. The cumulative normalization rates of alkaline phosphatase, gamma-glutamyltransferase, and immunoglobulin M (IgM) were significantly higher in patients without cirrhosis-related symptoms or liver-related events than in those with them. Overall, IgM constantly emerged as a significant factor associated with cirrhosis-related symptoms and liver-related events at all time points. Cumulative survival rates were significantly lower in patients with IgM ≥ 240 mg/dL than in patients with IgM < 240 mg/dL. Thus, normalization of IgM levels was a good surrogate predictor of long-term prognosis. None of the patients discontinued combination therapy due to any adverse events during the follow-up period.

CONCLUSIONS

Our findings point to the beneficial effects of long-term UDCA plus bezafibrate combination therapy for UDCA-refractory PBC patients, and IgM response can be a useful predictive biomarker of long-term clinical outcomes.

Epidemiological and clinical features of primary biliary cholangitis in two Croatian regions: a retrospective study

AIM

To assess the measures of disease frequency and determine the clinical features of primary biliary cholangitis (PBC) in two Croatian regions.

METHODS

Databases of two tertiary hospitals, one located in the continental and one in the coastal region of Croatia, were retrospectively searched for PBC patients diagnosed from 2007 to 2018. Epidemiologic data analysis was restricted to patients from each hospital's catchment area. We analyzed factors related to response to therapy and event-free survival (EFS), defined as absence of ascites, variceal bleeding, encephalopathy, hepatocellular carcinoma, liver transplantation (LT), or death. In addition, we determined clinical and demographic data of transplanted PBC patients.

RESULTS

Out of 83 PBC patients, 86.7% were female, with a median age at diagnosis of 55 years. Average PBC incidence for the 11-year period was 0.79 and 0.89 per 100000 population, whereas the point prevalence on December 31, 2017 was 11.5 and 12.5 in the continental and coastal region, respectively. Of 76 patients with complete medical records, 21% had an advanced disease stage, 31.6% had an associated autoimmune condition, and all received ursodeoxycholic acid. EFS rate at 5 years was 95.8%. In an age and sex-adjusted multivariate Cox regression model, the only factor significantly associated with inferior EFS was no response to therapy (HR=18.4; P=0.018). Of all Croatian patients who underwent LT, 3.8% had PBC, with the survival rate at 5 years after LT of 93.4%.

CONCLUSION

This study gives pioneer insights into the epidemiological and clinical data on PBC in Croatia, thus complementing the PBC map of Southeast Europe.

Pharmacokinetics and Pharmacodynamics of Ursodeoxycholic Acid in an Overweight Population With Abnormal Liver Function

Ursodeoxycholic acid (UDCA) is a secondary bile acid that is used to treat primary biliary cholangitis. Although UDCA has a hepatoprotective effect in some diseases, its benefit in nonalcoholic fatty liver disease (NAFLD) remains controversial. We aimed to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of UDCA in overweight subjects with elevated liver enzymes after multiple administrations of UDCA and compare these changes with vitamin E treatment. Overweight subjects (body mass index, 25-30 kg/m² ) with elevated alanine aminotransferase (ALT) level (40-200 IU/L) were enrolled. Subjects received one of the following three 8-week treatments: UDCA 300 mg twice daily UDCA 300 mg twice daily for 4 weeks followed by UDCA 300 mg twice daily and metformin 500 mg twice daily for 4 weeks, and vitamin E 400 IU twice daily. PK and PD (liver function, lipid profiles, insulin sensitivity, and miR-122) analyses were performed. Thirty subjects were enrolled; 1 subject withdrew his consent during the study. The PK characteristics were similar to those of healthy volunteers. The ALT and miR-122 levels decreased in the UDCA groups, whereas the ALT and aspartate aminotransferase levels decreased in the vitamin E group. The lipid profiles and insulin sensitivity did not show significant changes among the groups. There was no serious adverse event, and the safety profiles were similar among the treatment groups. The liver enzyme and miR-122 levels were decreased by UDCA. Considering UDCA and vitamin E have a hepatoprotective effect and different mechanisms of action, combination therapy could be an option for NAFLD.

The future of autoimmune liver diseases - Understanding pathogenesis and improving morbidity and mortality

Autoimmune liver diseases (AILD), namely autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), are rare diseases. These days, patients with PBC almost never require liver transplantation. When treated early with ursodeoxycholic acid patients have a normal life expectancy if the disease is diagnosed at an early stage and the patients respond to treatment. Patients with AIH often go into remission with first-line therapy including corticosteroids alone or in combination with azathioprine. Nevertheless, about one quarter of patients already developed cirrhosis at diagnosis. Those who do not respond to first line standard of care (SOC) have significant liver-related morbidity and mortality. No approved second- or third-line treatments are available and the drugs are selected based on limited case series and personal experience. Larger trials are needed to develop efficient therapies for difficult-to-treat AIH patients. No treatment has been found to alter the natural course of disease in patients with PSC except for liver transplantation. Identifying PSC patients at risk of developing cholangiocarcinoma (CCA) is another unmet need. Current research in all AILD including AIH, PBC and PSC, focuses on improving our understanding of the underlying disease process and identifying new therapeutic targets to decrease morbidity and mortality.

Prognostic significance of serum tyrosine concentration in patients with primary biliary cholangitis under ursodeoxycholic acid therapy

AIM

Chronic liver insufficiency is often associated with alteration in amino acid metabolism. We evaluated the prognostic value of changes in serum amino acid concentrations in patients with primary biliary cholangitis.

METHODS

A total of 75 primary biliary cholangitis patients who started urusodeoxycholic acid therapy were retrospectively enrolled. Baseline serum concentrations of branched-chain amino acids and tyrosine, and branched-chain amino acid-to-tyrosine ratio were determined. The hazard ratios of factors associated with liver-related events were analyzed by Cox proportional hazard analysis.

RESULTS

Of the 75 patients enrolled, 12 showed a decrease in serum branched-chain amino acid levels, and 15 showed an increase in serum tyrosine levels. The branched-chain amino acid-to-tyrosine ratio decreased in 16 patients. During a median 5.6-year follow up, liver-related events occurred in 11 patients. Multivariate analysis showed that high serum tyrosine levels at baseline and high alkaline phosphatase levels 48 weeks after starting urusodeoxycholic acid therapy were independent risk factors for event occurrence. From the receiver operator characteristics curve analysis, serum tyrosine concentration >110 μmol/L was identified as a cut-off value with an adjusted hazard ratio of 20.9 (95% confidence interval 4.3-101.5, P < 0.001). Kaplan-Meier analysis showed that the 5-year cumulative incidences of event occurrence in patients with high and low serum tyrosine concentration were 56.5% and 5.5%, respectively (P < 0.001). The 10-year survival probabilities also showed significant differences between patients with high and low serum tyrosine concentration (44.9% vs. 92.0%, P < 0.001).

CONCLUSION

Elevation of serum tyrosine concentration indicates a high risk of liver-related events in primary biliary cholangitis patients receiving urusodeoxycholic acid therapy.

Drug Therapies for Chronic Cholestatic Liver Diseases

Though ursodeoxycholic acid (UDCA) remains the baseline treatment for most cholestatic liver diseases, UDCA treatment leaves approximately one-third of patients with primary biliary cholangitis (PBC) and all patients with primary sclerosing cholangitis (PSC) at risk for disease progression. New anticholestatic agents, including nuclear receptor agonists, choleretics, and bile acid synthesis suppressors, will likely increase response rates to therapy in PBC and PSC. Strategies that target early immune-mediated injury have so far been disappointing, hampered by the lack of biomarkers to detect early disease states, which then could profit from immunomodulatory therapy. Future concepts need to personalize treatments according to disease stage, progression, and phase, and to combine multiple drugs to target different pathogenic pathways.

Emerging therapies for PBC

Primary biliary cholangitis is an uncommon cholestatic liver disease predominantly affecting middle-aged women. Left untreated, there is a high risk of progression to end-stage liver disease. Few treatment options exist. To date, ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are the only medical therapies approved for use, other than symptomatic treatments and liver transplantation, the latter of which is reserved for those developing complications of cirrhosis or with intractable pruritus. UDCA improves outcomes, but many patients do not adequately respond. OCA therapy may improve response, but long-term data are limited. New therapies are desperately needed, but evaluation has been limited by the fact that the disease is heterogeneous, hard end points take years to develop, and there are different criteria in use for determining therapeutic response based on surrogate biomarkers. Fibrates appear to be the most promising new therapy and have beneficially affected surrogate end points and are beginning to show improvement in clinical end points.

Lignans from Schisandra sphenanthera protect against lithocholic acid-induced cholestasis by pregnane X receptor activation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cholestasis is a clinical syndrome caused by toxic bile acid retention that will lead to serious liver diseases. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are the only two FDA-approved drugs for its treatment. Thus, there is a clear need to develop new therapeutic approaches for cholestasis. Here, anti-cholestasis effects of the lignans from a traditional Chinese herbal medicine, Schisandra sphenanthera, were investigated as well as the involved mechanisms.

MATERIALS AND METHODS

Adult male C57BL/6J mice were randomly divided into 9 groups including the control group, LCA group, LCA with specific lignan treatment of Schisandrin A (SinA), Schisandrin B (SinB), Schisandrin C (SinC), Schisandrol A (SolA), Schisandrol B (SolB), Schisantherin A (StnA) and Schisantherin B (StnB), respectively. Mice were treated with each drug (qd) for 7 days, while the administration of lithocholic acid (LCA) (bid) was launched from the 4th day. Twelve hours after the last LCA injection, mice were sacrificed and samples were collected. Serum biochemical measurement and histological analysis were conducted. Metabolomics analysis of serum, liver, intestine and feces were performed to study the metabolic profile of bile acids. RT-qPCR and Western blot analysis were conducted to determine the hepatic expression of genes and proteins related to bile acid homeostasis. Dual-luciferase reporter gene assay was performed to investigate the transactivation effect of lignans on human pregnane X receptor (hPXR). RT-qPCR analysis was used to detect induction effects of lignans on hPXR-targeted genes in HepG2 cells.

RESULTS

Lignans including SinA, SinB, SinC, SolA, SolB, StnA, StnB were found to significantly protect against LCA-induced intrahepatic cholestasis, as evidenced by significant decrease in liver necrosis, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activity. More importantly, serum total bile acids (TBA) and total bilirubin (Tbili) were also significantly reduced. Metabolomics analysis revealed these lignans accelerated the metabolism of bile acids and increased the bile acid efflux from liver into the intestine or feces. Gene analysis revealed these lignans induced the hepatic expressions of PXR-target genes such as Cyp3a11 and Ugt1a1. Luciferase reporter gene assays illustrated that these bioactive lignans can activate hPXR. Additionally, they can all upregulate hPXR-regulate genes such as CYP3A4, UGT1A1 and OATP2.

CONCLUSION

These results clearly demonstrated the lignans from Schisandra sphenanthera exert hepatoprotective effects against LCA-induced cholestasis by activation of PXR. These lignans may provide an effective approach for the prevention and treatment of cholestatic liver injury.

Bezafibrate Improves GLOBE and UK-PBC Scores and Long-Term Outcomes in Patients With Primary Biliary Cholangitis

In Japan, bezafibrate (BF) is a second-line agent for primary biliary cholangitis (PBC) that is refractory to ursodeoxycholic acid (UDCA) treatment. From a retrospective cohort (n = 873) from the Japan PBC Study Group, we enrolled 118 patients who had received UDCA monotherapy for at least 1 year followed by combination therapy with UDCA+BF for at least 1 year. GLOBE and UK-PBC scores after UDCA monotherapy (i.e., immediately before UDCA+BF combination therapy) were compared with those after 1 year of UDCA+BF combination therapy. The real outcomes of enrolled patients estimated by Kaplan-Meier analysis were compared with the predicted outcomes calculated using GLOBE and UK-PBC scores. In addition, the hazard ratio of BF treatment was calculated using propensity score analysis. The mean GLOBE score before the combination therapy was 0.504 ± 0.080, which improved significantly to 0.115 ± 0.085 (P < 0.0001) after 1 year of combination therapy. The real liver transplant-free survival of enrolled patients was significantly better than that predicted by GLOBE score before introducing BF. Combination therapy did not significantly improve the real rates of liver transplantation or liver-related death compared with those predicted by UK-PBC risk score before introducing BF, but the predicted risk was significantly reduced by the addition of BF (P < 0.0001). Cox regression analysis with inverse probability of treatment weighting showed that the addition of BF significantly reduced the hazard of liver transplant or liver-related death in patients who, after 1 year of UDCA monotherapy, had normal serum bilirubin (adjusted hazard ratio 0.09, 95% confidence interval 0.01-0.60, P = 0.013). Conclusion: Addition of BF to UDCA monotherapy improves not only GLOBE and UK-PBC scores but also the long-term prognosis of PBC patients, especially those with early-stage PBC.

Evolving liver inflammation in biochemically normal individuals with anti-mitochondria antibodies

Background

Anti-mitochondria autoantibodies (AMA) occur in > 95% primary biliary cholangitis (PBC) patients. Biochemically normal AMA-positive (BN/AMA+) individuals, occasionally noticed by indirect immunofluorescence (IIF) on HEp-2 cells and confirmed in AMA-specific assays, may represent early stages of PBC. The Enhanced Liver Fibrosis (ELF) score is a surrogate marker for liver fibrosis. This prospective study investigated the ELF score in BN/AMA+ individuals and PBC patients, considering autoantibody avidity and serum levels along the years.

Methods

327 samples from 35 PBC and 59 BN/AMA+ were prospectively obtained in average 3.83 (range 0.50-7.40) years apart. Samples were tested by IIF on rat-kidney (IIF-AMA), western-blot for AMA (WB-AMA), and ELISA for antibodies against pyruvate-dehydrogenase (PDC-E2), gp210, sp100 and CENP-A/B. Anti-PDC-E2 avidity was determined by 6 M urea-elution ELISA. Alkaline phosphatase (ALP), gamma glutamyl transferase (ɣGT) and ELF score were measured by automated methods.

Results

Along the follow-up period BN/AMA+ subjects and PBC patients presented significant increase in serum anti-PDC-E2 (mean 10.45% and 8.86% per year; respectively), anti-PDC-E2 avidity (3.02% and 4.94%/year) and ELF score (3.24% and 2.71%/year). IIF-AMA and ɣGT increased in BN/AMA+ (6.59% and 2.36%) and decreased in PBC (- 4.89%/year and - 3.88%/year). In BN/AMA+ individuals there was positive correlation of ELF with IIF-AMA titer (r = 0.465; p < 0.001) and with anti-PDC-E2 levels (r = 0.239; p < 0.001). Expansion of autoantibody targets along time occurred in 39% BN/AMA+ and 49% PBC patients. The frequency of BN/AMA+ with high probability of having established PBC increased from 7 to 14%.

Conclusions

BN/AMA+ individuals present an orchestrated increase in ELF score and humoral autoimmune response over time, indicating an opportunity for early therapeutic intervention and prevention in autoimmunity.

Exploration and Development of PPAR Modulators in Health and Disease: An Update of Clinical Evidence

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that govern the expression of genes responsible for energy metabolism, cellular development, and differentiation. Their crucial biological roles dictate the significance of PPAR-targeting synthetic ligands in medical research and drug discovery. Clinical implications of PPAR agonists span across a wide range of health conditions, including metabolic diseases, chronic inflammatory diseases, infections, autoimmune diseases, neurological and psychiatric disorders, and malignancies. In this review we aim to consolidate existing clinical evidence of PPAR modulators, highlighting their clinical prospects and challenges. Findings from clinical trials revealed that different agonists of the same PPAR subtype could present different safety profiles and clinical outcomes in a disease-dependent manner. Pemafibrate, due to its high selectivity, is likely to replace other PPARα agonists for dyslipidemia and cardiovascular diseases. PPARγ agonist pioglitazone showed tremendous promises in many non-metabolic disorders like chronic kidney disease, depression, inflammation, and autoimmune diseases. The clinical niche of PPARβ/δ agonists is less well-explored. Interestingly, dual- or pan-PPAR agonists, namely chiglitazar, saroglitazar, elafibranor, and lanifibranor, are gaining momentum with their optimistic outcomes in many diseases including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and primary biliary cholangitis. Notably, the preclinical and clinical development for PPAR antagonists remains unacceptably deficient. We anticipate the future design of better PPAR modulators with minimal off-target effects, high selectivity, superior bioavailability, and pharmacokinetics. This will open new possibilities for PPAR ligands in medicine.

The challenges of primary biliary cholangitis: What is new and what needs to be done

Primary Biliary Cholangitis (PBC) is an uncommon, chronic, cholangiopathy of autoimmune origin and unknown etiology characterized by positive anti-mitochondrial autoantibodies (AMA), female preponderance and progression to cirrhosis if left untreated. The diagnosis is based on AMA- or PBC-specific anti-nuclear antibody (ANA)-positivity in the presence of a cholestatic biochemical profile, histologic confirmation being mandatory only in seronegative cases. First-line treatment is ursodeoxycholic acid (UDCA), which is effective in preventing disease progression in about two thirds of the patients. The only approved second-line treatment is obeticholic acid. This article summarizes the most relevant conclusions of a meeting held in Lugano, Switzerland, from September 23rd-25th 2018, gathering basic and clinical scientists with various background from around the world to discuss the latest advances in PBC research. The meeting was dedicated to Ian Mackay, pioneer in the field of autoimmune liver diseases. The role of liver histology needs to be reconsidered: liver pathology consistent with PBC in AMA-positive individuals without biochemical cholestasis is increasingly reported, raising the question as to whether biochemical cholestasis is a reliable disease marker for both clinical practice and trials. The urgent need for new biomarkers, including more accurate markers of cholestasis, was also widely discussed during the meeting. Moreover, new insights in interactions of bile acids with biliary epithelia in PBC provide solid evidence of a role for impaired epithelial protection against potentially toxic hydrophobic bile acids, raising the fundamental question as to whether this bile acid-induced epithelial damage is the cause or the consequence of the autoimmune attack to the biliary epithelium. Strategies are needed to identify difficult-to-treat patients at an early disease stage, when new therapeutic approaches targeting immunologic pathways, in addition to bile acid-based therapies, may be effective. In conclusion, using interdisciplinary approaches, groundbreaking advances can be expected before long in respect to our understanding of the etiopathogenesis of PBC, with the ultimate aim of improving its treatment.

Identification of clinical risk factors for histological progression of primary biliary cholangitis

AIM

To identify laboratory predictors of histological progression (HP) of primary biliary cholangitis (PBC).

METHODS

Sequential biopsies were carried out on 35 (11.4%) of 308 patients with PBC treated with ursodeoxycholic acid (UDCA). Patients were divided into high γ-glutamyl transpeptidase (GGT) (n = 18) and low GGT (n = 17) groups, based on the median value of GGT at baseline. Patients were then categorized as showing HP (progressive group, PG) or lacking HP (non-progressive group, NPG) according to the Scheuer and Nakanuma classifications, with the latter grading liver fibrosis (fibrosis score) and bile duct loss (BDL score).

RESULTS

According to the Scheuer definition, 12 patients had HP and 23 did not. According to the Nakanuma definition, 8 and 27 patients were in the PG and NPG groups, respectively. The fibrosis and BDL scores progressed in 13 and 8 patients, respectively, whereas 22 and 25 patients did not show HP, respectively. Fisher's exact probability test analysis revealed that the rate of HP using the Nakanuma fibrosis score was significantly higher in the high GGT group compared to the low GGT group (P < 0.05). However, no significant correlation was found between the HP of PBC and the biochemical response to UDCA therapy. Both univariate and multivariate logistic regression analyses indicated that the serum GGT level at baseline is an independent risk factor for an increased Nakanuma fibrosis score.

CONCLUSIONS

The level of serum GGT at baseline is significantly associated with liver fibrosis progression in PBC, and therefore could help to predict the HP of PBC.

Ursodeoxycholic acid therapy and liver transplant-free survival in patients with primary biliary cholangitis

BACKGROUND & AIMS

The clinical efficacy of ursodeoxycholic acid (UDCA) in primary biliary cholangitis (PBC) remains subject to debate as definitive randomized controlled trials are lacking. We aimed to determine whether UDCA prolongs liver transplant (LT)-free survival in patients with PBC.

METHODS

This international cohort study included patients from the Global PBC Study Group database, originating from 8 countries in Europe and North America. Both UDCA-treated and untreated patients were included. LT and death were assessed as a combined endpoint through Cox regression analyses, with inverse probability treatment weighting (IPTW).

RESULTS

In the 3,902 patients included, the mean (SD) age was 54.3 (11.9) years, 3,552 patients (94.0%) were female, 3,529 patients (90.4%) were treated with UDCA and 373 patients (9.6%) were not treated. The median (interquartile range) follow-up was 7.8 (4.1-12.1) years. In total, 721 UDCA-treated patients and 145 untreated patients died or underwent LT. After IPTW, the 10-year cumulative LT-free survival was 79.7% (95% CI 78.1-81.2) among UDCA-treated patients and 60.7% (95% CI 58.2-63.4) among untreated patients (p <0.001). UDCA was associated with a statistically significant reduced risk of LT or death (hazard ratio 0.46, 95% CI 0.40-0.52; p <0.001). The hazard ratio remained statistically significant in all stages of disease. Patients classified as inadequate biochemical responders after 1 year of UDCA had a lower risk of LT or death than patients who were not treated (adjusted hazard ratio 0.56; 95% CI 0.45-0.69; p <0.001).

CONCLUSION

The use of UDCA improves LT-free survival among patients with PBC, regardless of the disease stage and the observed biochemical response. These findings support UDCA as the current universal standard of care in PBC.

LAY SUMMARY

In this international multicenter study of 3,902 patients with primary biliary cholangitis, we found that treatment with ursodeoxycholic acid is associated with prolonged liver transplant-free survival. This association was significant, irrespective of sex, age, or disease stage. The survival benefit remained statistically significant in patients with an incomplete biochemical response to ursodeoxycholic acid therapy.

Cholestatic liver diseases: An era of emerging therapies

Recently the field of cholestasis has expanded enormously reflecting an improved understanding of the molecular mechanisms underlying bile secretion and its perturbation in chronic cholestatic disease. Novel anti-cholestatic therapeutic options have been developed for patients not favorably responding to ursodeoxycholic acid (UDCA), the current standard treatment for cholestatic liver disease. Important novel treatment targets now also include nuclear receptors involved in bile acid (BA) homoeostasis like farnesoid X receptor and G protein-coupled receptors e.g., the G-protein-coupled BA receptor "transmembrane G coupled receptor 5". Fibroblast growth factor-19 and enterohepatic BA transporters also deserve attention as additional drug targets as does the potential treatment agent norUDCA. In this review, we discuss recent and future promising therapeutic agents and their potential molecular mechanisms in cholestatic liver disorders.

Promoter hypermethylation of the AE2/SLC4A2 gene in PBC

Background & Aims

Patients with primary biliary cholangitis (PBC) exhibit reduced AE2/SLC4A2 gene expression in the liver and peripheral blood mononuclear cells (PBMCs). AE2 encodes a Cl^–/HCO₃^– exchanger involved in biliary bicarbonate secretion and intracellular pH regulation. Reduced AE2 expression in PBC may be pathogenic, as Ae2-knockout mice reproduce characteristic PBC features. Herein, we aimed to identify CpG-methylation abnormalities in AE2 promoter regions that might contribute to the reduced gene transcription in PBC livers and PBMCs.

Methods

CpG-cytosine methylation rates were interrogated at 1-base pair resolution in upstream and alternate AE2 promoter regions through pyrosequencing of bisulphite-modified genomic DNA from liver specimens and PBMCs. AE2a and alternative AE2b1 and AE2b2 mRNA levels were measured by real-time PCR. Human lymphoblastoid-T2 cells were treated with 5-aza-2´-deoxycytidine for demethylation assays.

Results

AE2 promoters were found to be hypermethylated in PBC livers compared to normal and diseased liver specimens. Receiver operating characteristic (ROC) curve analysis showed that minimal CpG-hypermethylation clusters of 3 AE2a-CpG sites and 4 alternate-AE2b2-CpG sites specifically differentiated PBC from normal and diseased controls, with mean methylation rates inversely correlating with respective transcript levels. Additionally, in PBMCs a minimal cluster of 3 hypermethylated AE2a-CpG sites distinguished PBC from controls, and mean methylation rates correlated negatively with AE2a mRNA levels in these immune cells. Alternate AE2b2/AE2b1 promoters in PBMCs were constitutively hypermethylated, in line with absent alternative mRNA expression in diseased and healthy PBMCs. Demethylation assays treating lymphoblastoid-T2 cells with 5-aza-2´-deoxycytidine triggered AE2b2/AE2b1 expression and upregulated AE2a-promoter expression.

Conclusions

Disease-specific hypermethylation of AE2 promoter regions and subsequent downregulation of AE2-gene expression in the liver and PBMCs of patients with PBC might be critically involved in the pathogenesis of this complex disease.

Lay summary

Primary biliary cholangitis (PBC) is a chronic immune-associated cholestatic liver disease with unclear complex/multifactorial etiopathogenesis affecting mostly middle-aged women. Patients with PBC exhibit reduced expression of the AE2/SLC4A2 gene. Herein, we found that AE2 promoter regions are hypermethylated in the liver and peripheral blood mononuclear cells of patients with PBC. This increased methylation is associated with downregulated AE2-gene expression, which might contribute to the pathogenesis of PBC. Therefore, novel epigenetic targets may improve treatment in patients with PBC who respond poorly to current pharmacological therapies.

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Patients with PBC have higher AE2 CpG methylation in upstream AE2a and/or AE2b2/AE2b1 promoter regions in liver and PBMCs.

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Combined methylation rates of 2 minimal CpG-clusters in the liver and 1 minimal CpG-cluster in PBMCs specifically distinguished PBC from normal and diseased controls.

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Methylation rates of AE2 promoter regions inversely correlated with levels of respective AE2 mRNAs in liver and PBMCs.

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Alternate AE2b2/AE2b1 promoter regions were found to be densely methylated in both normal and diseased PBMC samples.