Current and potential treatments for primary biliary cholangitis

Prolonged use of pentoxifylline increases the life expectancy of patients with compensated cirrhosis: A 20‑year retrospective study

Liver cirrhosis is a pathology of varied etiology with a high prevalence and mortality, resulting in >1 million mortalities per year. Patients with liver cirrhosis typically have a survival time of 12 years following diagnosis. The treatment for this disease is directed at the complications of cirrhosis; however, to the best of our knowledge, the long-term management of patients with cirrhosis has been scarcely studied. Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor with rheological activity and antioxidant, anti-inflammatory and antifibrotic properties. PTX has been used in the treatment of peripheral arterial disease, inflammatory liver diseases and hepatocellular carcinoma with encouraging results. The aim of the present study was to evaluate the effect of PTX use on the survival of patients with compensated cirrhosis. For this purpose, a cross-sectional study was performed at the Gastroenterology and Hepatitis C Department of Dr. Valentín Gómez Farias Hospital (Institute for Security and Social Services for State Workers, Zapopan, Mexico) from June, 1996 to December, 2019. The follow-up time for these patients was 22.6 years (up to the end of the study period). In the present study, 326 patient files were analyzed and 118 patients with the disease were identified, 81 of whom (68.64%) died within 12 years after diagnosis. Of the included patients, 26 received PTX combined with PEG IFN-α-2a plus ribavirin, and 11 received PTX plus propranolol, with a median treatment duration of 20.6±0.8 years. Furthermore, 16 patients (43%) did not develop co-morbidities within this time, and the transition to decompensated cirrhosis was 16.6 years, with a survival time of 20 years. Therefore, the results of the present study suggest that PTX may improve the long-term survival of patients with compensated cirrhosis, rendering PTX a candidate for repurposing in the treatment of hepatic cirrhosis.

The potential role of mitochondria in the microbiota-gut-brain axis: Implications for brain health

Mitochondria are crucial organelles that regulate cellular energy metabolism, calcium homeostasis, and oxidative stress responses, playing pivotal roles in brain development and neurodegeneration. Concurrently, the gut microbiota has emerged as a key modulator of brain physiology and pathology through the microbiota-gut-brain axis. Recent evidence suggests an intricate crosstalk between the gut microbiota and mitochondrial function, mediated by microbial metabolites that can influence mitochondrial activities in the brain. This review aims to provide a comprehensive overview of the emerging role of mitochondria as critical mediators in the microbiota-gut-brain axis, shaping brain health and neurological disease pathogenesis. We discuss how gut microbial metabolites such as short-chain fatty acids, secondary bile acids, tryptophan metabolites, and trimethylamine N-oxide can traverse the blood-brain barrier and modulate mitochondrial processes including energy production, calcium regulation, mitophagy, and oxidative stress in neurons and glial cells. Additionally, we proposed targeting the mitochondria through diet, prebiotics, probiotics, or microbial metabolites as a promising potential therapeutic approach to maintain brain health by optimizing mitochondrial fitness. Overall, further investigations into how the gut microbiota and its metabolites regulate mitochondrial bioenergetics, dynamics, and stress responses will provide valuable insights into the microbiota-gut-brain axis in both health and disease states.

Single-cell RNA sequencing reveals the pro-inflammatory roles of liver-resident Th1-like cells in primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by multilineage immune dysregulation, which subsequently causes inflammation, fibrosis, and even cirrhosis of liver. Due to the limitation of traditional assays, the local hepatic immunopathogenesis of PBC has not been fully characterized. Here, we utilize single-cell RNA sequencing technology to depict the immune cell landscape and decipher the molecular mechanisms of PBC patients. We reveal that cholangiocytes and hepatic stellate cells are involved in liver inflammation and fibrosis. Moreover, Kupffer cells show increased levels of inflammatory factors and decreased scavenger function related genes, while T cells exhibit enhanced levels of inflammatory factors and reduced cytotoxicity related genes. Interestingly, we identify a liver-resident Th1-like population with JAK-STAT activation in the livers of both PBC patients and murine PBC model. Finally, blocking the JAK-STAT pathway alleviates the liver inflammation and eliminates the liver-resident Th1-like cells in the murine PBC model. In conclusion, our comprehensive single-cell transcriptome profiling expands the understanding of pathological mechanisms of PBC and provides potential targets for the treatment of PBC in patients.

Rosacea and autoimmune liver diseases: a two-sample Mendelian randomization study

Rosacea and autoimmune liver diseases (AILDs) are diseases closely associated with immune system abnormalities. AILDs primarily includes autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). Currently, research on the association between these two conditions is limited. Therefore, this study employed the bidirectional Mendelian randomization (MR) method to investigate potential causal relationships between rosacea and AILDs based on genetic predictions. Summary data related to Rosacea, AIH, PSC, and PBC were obtained from public genome-wide association studies (GWAS). The inverse variance weighted (IVW) method was used as the primary analytical approach, supplemented by the MR-Egger, weighted mode method, weighted median, and simple mode. A series of sensitivity analyses were also conducted to identify heterogeneity and pleiotropy effects. The MR analysis results indicated a significant increase in the risk of rosacea being associated with PBC (OR = 1.09, 95% CI = 1.02-1.18, P = 0.014), but no such association was found with AIH or PSC. Furthermore, this study did not find a significant impact of rosacea on the risk of AILDs. This study represents the first in-depth exploration of the potential causal relationship between rosacea and AILDs using MR analysis. Thes findings suggest an increased risk of rosacea among PBC patients.

The Impact of Histologic Portal T-Cell Density on the Clinical Outcomes in Hepatic Graft-versus-Host Disease and Autoimmune Liver Diseases

Hepatic graft-versus-host disease (GVHD) significantly impacts morbidity and mortality among allogeneic hematopoietic stem cell transplant recipients. However, the relationship between clinical and immunopathological phenotypes and their influence on clinical outcomes in hepatic GVHD is not well understood. In this study, we aimed to study the implications of portal T-cell infiltration on the clinical outcomes in hepatic GHVD and its similarities to autoimmune liver disease. We analyzed 78 patients with biopsy-confirmed hepatic GVHD (n = 38) or autoimmune liver disease (n = 40) between 2016 and 2021. The cholestatic variant was defined by an R-value < 2.0, based on the ratio of alanine aminotransferase to alkaline phosphatase. The primary outcome was the biochemical response at 4 (early) and 8-12 (late) weeks after corticosteroid treatment. In hepatic GVHD patients, the hepatitic variant (n = 19) showed greater CD3+ T-cell infiltration than the cholestatic variant (n = 19; p < 0.001). No significant differences were observed in the infiltration of CD20+, CD38+, or CD68+ cells. The hepatitic variant had significantly better early and late responses and higher liver-related event-free survival than the cholestatic variants (p < 0.05). Concerning autoimmune liver diseases, the autoimmune hepatitis (AIH) group had significantly more portal T-cell infiltration and better treatment responses than the primary biliary cholangitis (PBC) group. In conclusion, higher portal T-cell infiltration may be associated with better clinical outcomes in patients with hepatic GVHD. Additionally, this study highlights similarities in portal T-cell infiltration and treatment response patterns between AIH and the hepatitic variant, as well as PBC and the cholestatic variant.

Picroside II promotes HSC apoptosis and inhibits the cholestatic liver fibrosis in Mdr2-/- mice by polarizing M1 macrophages and balancing immune responses

Liver fibrosis is characterized by chronic inflammatory responses and progressive fibrous scar formation. Macrophages play a central role in the pathogenesis of hepatic fibrosis by reconstructing the immune microenvironment. Picroside II (PIC II), extracted from Picrorhizae Rhizoma, has demonstrated therapeutic potential for various liver damage. However, the mechanisms by which macrophage polarization initiates immune cascades and contributes to the development of liver fibrosis, and whether this process can be influenced by PIC II, remain unclear. In the current study, RNA sequencing and multiple molecular approaches were utilized to explore the underlying mechanisms of PIC II against liver fibrosis in multidrug-resistance protein 2 knockout (Mdr2-/-) mice. Our findings indicate that PIC II activates M1-polarized macrophages to recruit natural killer cells (NK cells), potentially via the CXCL16-CXCR6 axis. Additionally, PIC II promotes the apoptosis of activated hepatic stellate cells (aHSCs) and enhances the cytotoxic effects of NK cells, while also reducing the formation of neutrophil extracellular traps (NETs). Notably, the anti-hepatic fibrosis effects associated with PIC II were largely reversed by macrophage depletion in Mdr2-/- mice. Collectively, our research suggests that PIC II is a potential candidate for halting the progression of liver fibrosis.

Hypercholesterolemia Is Associated With Dysregulation of Lipid Metabolism and Poor Prognosis in Primary Biliary Cholangitis

BACKGROUND & AIMS

Hypercholesterolemia is frequently diagnosed in patients with primary biliary cholangitis (PBC). However, its association with the prognosis and lipid metabolism is unknown. In this study, we aimed to investigate the prognostic value of baseline total cholesterol (TC) levels in PBC and characterized the associated lipid metabolism.

METHODS

Five hundred and thirty-one patients with PBC without prior cirrhosis-related complications were randomly divided into the derivation and validation cohorts at a ratio of 7:3. Complete clinical data were obtained and analyzed. The endpoints were defined as liver-related death, liver transplantation, and cirrhosis-related complications. Lipidomics was performed in 89 patients and 28 healthy controls.

RESULTS

Baseline TC was independently associated with poor liver-related outcomes, and adjusted C-statistics were 0.80 (95% confidence interval [CI]: 0.74-0.85) and 0.88 (95% CI: 0.78-0.91) in the derivation and validation cohorts, respectively. The predictive ability of TC for disease outcomes was stable over time and comparable with the Globe score. The 200 mg/dL cut-off optimally divided patients into low- and high-TC groups. A combination of TC and Globe score provided a more accurate stratification of patients into risk subgroups. Lipidomics indicated an up-regulation of lipid families in high-TC patients. Pathway analysis of 66 up-regulated lipids revealed the dysregulation of glycerophospholipid and sphingolipid metabolism in high-TC patients, which were associated with poor liver-related outcomes.

CONCLUSIONS

Our results indicate that patients with PBC having baseline TC levels above 200 mg/dL have unique lipidome characteristics and are at a higher risk of poor liver-related outcomes.

A fungal P450 enzyme from Fusarium equiseti HG18 with 7β-hydroxylase activity in biosynthesis of ursodeoxycholic acid

Cytochrome P450 enzyme with 7β-hydroxylation capacity has attracted widespread attentions due to the vital roles in the biosynthesis of ursodeoxycholic acid (UDCA), a naturally active molecule for the treatment of liver and gallbladder diseases. In this study, a novel P450 hydroxylase (P450FE) was screen out from Fusarium equiseti HG18 and identified by a combination of genome and transcriptome sequencing, as well as heterologous expression in Pichia pastoris. The biotransformation of lithocholic acid (LCA) by whole cells of recombinant Pichia pastoris further confirmed the C7β-hydroxylation with 5.2% UDCA yield. It was firstly identified a fungal P450 enzyme from Fusarium equiseti HG18 with the capacity to catalyze the LCA oxidation producing UDCA. The integration of homology modeling and molecular docking discovered the substrate binding to active pockets, and the key amino acids in active center were validated by site-directed mutagenesis, and revealed that Q112, V362 and L363 were the pivotal residues of P450FE in regulating the activity and selectivity of 7β-hydroxylation. Specifically, V362I mutation exhibited 2.6-fold higher levels of UDCA and higher stereospecificity than wild-type P450FE. This advance provided guidance for improving the catalytic efficiency and selectivity of P450FE in LCA hydroxylation, indicative of the great potential in green synthesis of UDCA from biologically toxic LCA.

A new and simple score to predict adequate and deep response to ursodeoxycholic acid in patients with primary biliary cholangitis: the ALP-A score

BACKGROUND

Ursodeoxycholic acid (UDCA) is the standard treatment for primary biliary cholangitis (PBC), but a significant proportion of patients do not respond adequately, leading to increased risk of adverse outcomes. This study aims to develop a new and straightforward predictive score to identify PBC patients likely to achieve a complete response to UDCA.

METHODS

A logistic regression analysis was conducted using a derivation cohort of PBC patients to identify pre-treatment variables associated with response to UDCA. This analysis led to the development of the ALP-A score, calculated as: Age at diagnosis divided by (alkaline phosphatase at diagnosis/upper limit of normal). ALP-A score accuracy was evaluated using the area under the ROC curve, validated with a large external cohort from Brazil. Additionally, the correlation between the ALP-A score and the previously validated UDCA response score (URS) was assessed.

RESULTS

ALP-A score had good predictive power for adequate (AUC 0.794; 95% CI, 0.737-0.852) and deep (0.76; 95% CI, 0.69-0.83) UDCA response at 1 year of treatment. A cutoff score of 17 and 23 points was determined to be the optimal threshold for distinguishing adequate and deep responders, respectively, from non-responders. ALP-A score demonstrated a sensitivity of 73%, specificity of 71%, positive predictive value of 65%, negative predictive value of 78%, and overall accuracy of 72% for biochemical response. The URS displayed similar discriminative ability (AUC 0.798; 95% CI, 0.741-0.855).

CONCLUSION

ALP-A score performs comparably to URS but offers the great advantage of simplicity for routine clinical use. It serves as a valuable tool to identify PBC patients less likely to respond to UDCA treatment, facilitating early consideration of alternative therapeutic approaches.

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.

High neutrophil-lymphocyte ratio indicates a worse response to ursodeoxycholic acid in primary biliary cholangitis: a retrospective cohort study

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease characterized by inflammation of the interlobular bile ducts. Ursodeoxycholic acid (UDCA) is the only FDA approved first-line therapy for PBC, but up to 40% of patients with PBC have an incomplete response to UDCA. Neutrophil-to-lymphocyte (NLR) has been used to predict prognosis in various liver diseases. There is limited evidence on the treatment response to UDCA in PBC patients. Our study aimed to evaluate the relationship between NRL and the response to UDCA treatment in PBC patients.

METHODS

A total of 257 primary biliary cholangitis (PBC) patients treated with UDCA (13-15 mg/kg/d) were enrolled in this retrospective study. The response to treatment was evaluated based on alkaline phosphatase levels ≤1.67 times the upper limit of the normal value after 12 months of UDCA treatment. Multivariable logistic regression analysis was performed to investigate the association between NLR at baseline and the response to 12 months of UDCA treatment after adjusting for important confounding variables. The stability of the results was evaluated by unadjusted and adjusted models.

RESULTS

The results of multiple regression analysis showed that NLR at baseline was positively associated with the nonresponse to UDCA treatment after adjustments for potential confounders (age, sex, BMI, hypertension, arterial plaque, thyroid disease, jaundice, albumin, globulin, total bile acid, ALP, GGT, LDLC, total cholesterol, hemoglobin, and APTT) (OR = 1.370, 95% CI 1.066-1.761). These results reveal that NLR is an independent risk factor for UDCA treatment nonresponse.

CONCLUSIONS

Our results suggest that PBC patients with a high NLR had a worse response to UDCA therapy.

A population-based characterization study of anti-mitochondrial M2 antibodies and its consistency with anti-mitochondrial antibodies

OBJECTIVE

This study aims to estimate the prevalence of anti-mitochondrial antibody subtype M2 (AMA-M2) and assess its consistency with AMA in a general population.

METHODS

A total of 8954 volunteers were included to screen AMA-M2 using enzyme-linked immunosorbent assay. Sera with AMA-M2 >50 RU/mL were further tested for AMA using an indirect immunofluorescence assay.

RESULTS

The population frequency of AMA-M2 positivity was 9.67%, of which 48.04% were males and 51.96% were females. The AMA-M2 positivity in males had a peak and valley value of 7.81% and 16.88% in those aged 40 to 49 and ≥70 years, respectively, whereas it showed a balanced age distribution in females. Transferrin and immunoglobulin M were the risk factors for AMA-M2 positivity and exercise was the only protective factor. Of 155 cases with AMA-M2 >50 RU/mL, 25 cases were AMA-positive, with a female-to-male ratio of 5.25:1. Only 2 people, with very high AMA-M2 of 760 and >800 RU/mL, met the diagnostic criteria of primary biliary cholangitis (PBC), making the prevalence of PBC 223.36 per million in southern China.

CONCLUSION

We found that AMA-M2 has a low coincidence rate with AMA in the general population. A new decision-making point for AMA-M2 is needed to improve consistency with AMA and diagnostic accuracy.

Sequence of events leading to primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that is observed more frequently in middle-aged women. This disorder is considered an autoimmune disease, since liver injury is sustained by the presence of self-directed antimitochondrial antibodies targeting the bile duct cells. The prognosis may vary depending on an early diagnosis and response to therapy. However, nearly a third of patients can progress to liver cirrhosis, thus requiring a liver transplant. Traditional immunosuppressive therapies, commonly employed for other autoimmune diseases, have limited effects on PBC. In fact, dramatic functional changes that occur in the biliary epithelium in the course of inflammation play a major role in perpetuating the injury. In this minireview, after a background on the disease and possible predisposing factors, the sequential cooperation of cellular/molecular events leading to end-stage PBC is discussed in detail. The rise and maintenance of the autoimmune process, as well as the response of the biliary epithelia during inflammatory injury, are key factors in the progression of the disease. The so-called "ductular reaction (DR)", intended as a reactive expansion of cells with biliary phenotype, is a process frequently observed in PBC and partially understood. However, recent findings suggest a strict relationship between this pathological picture and the progression to liver fibrosis, cell senescence, and loss of biliary ducts. All these issues (onset of chronic inflammation, changes in secretive and proliferative biliary functions, DR, and its relationship with other pathological events) are discussed in this manuscript in an attempt to provide a snapshot, for clinicians and researchers, of the most relevant and sequential contributors to the progression of this human cholestatic disease. We believe that interpreting this disorder as a multistep process may help identify possible therapeutic targets to prevent evolution to severe disease.

Integrative bioinformatics analysis and experimental validation of key biomarkers for risk stratification in primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune liver disease, whose etiology is yet to be fully elucidated. Currently, ursodeoxycholic acid (UDCA) is the only first-line drug. However, 40% of PBC patients respond poorly to it and carry a potential risk of disease progression. So, in this study, we aimed to explore new biomarkers for risk stratification in PBC patients to enhance treatment.

METHODS

We first downloaded the clinical characteristics and microarray datasets of PBC patients from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified and subjected to enrichment analysis. Hub genes were further validated in multiple public datasets and PBC mouse model. Furthermore, we also verified the expression of the hub genes and developed a predictive model in our clinical specimens.

RESULTS

A total of 166 DEGs were identified in the GSE79850 dataset, including 95 upregulated and 71 downregulated genes. Enrichment analysis indicated that DEGs were significantly enriched in inflammatory or immune-related process. Among these DEGs, 15 risk-related genes were recognized and further validated in the GSE119600 cohort. Then, TXNIP, CD44, ENTPD1, and PDGFRB were identified as candidate hub genes. Finally, we proceeded to the next screening with these four genes in our serum samples and developed a three-gene panel. The gene panel could effectively identify those patients at risk of disease progression, yielding an AUC of 0.777 (95% CI, 0.657-0.870).

CONCLUSIONS

In summary, combining bioinformatics analysis and experiment validation, we identified TXNIP, CD44, and ENTPD1 as promising biomarkers for risk stratification in PBC patients.

[Response to Primary Biliary Cholangitis Treatment: Influencing Factors and the Role in Prognosis Prediction]

Objective

To examine the influencing factors and prognostic features of poor response to ursodeoxycholic acid (UDCA) treatment in primary biliary cholangitis (PBC) patients with dyslipidemia.

Methods

A retrospective study was conducted, covering 512 patients who had a confirmed diagnosis of PBC, and who received treatment at West China Hospital, Sichuan University between January 2009 and March 2022. According to their actual response to UDCA treatment, patients were divided into two groups, UDCA full-response group ( n=305) and UDCA non-responding group ( n=207). The data from the two groups were compared to predict the adverse factors influencing patient response and the area under the curve ( AUC) of the receiver operating characteristic (ROC) curve, identify the cut-off value of total cholesterol (TC), and analyze the differences in baseline laboratory test findings and the rate of responses to treatment. According to the TC cut-off value, patients were divided into a group with TC≥5.415 mmol/L and another group with TC<5.415 mmol/L. In addition, differences in the prognosis of the two groups were assessed by comparing the UK-PBC and GLOBE scores.

Results

The baseline data, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), triglycerides (TG), TC, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), were significantly increased in the UDCA non-responding group compared to those in the full-response group (all P<0.005), while the albumin level of the UDCA non-responding group was decreased compared to that of the full-response group ( P=0.012). Findings of multi-factor logistic regression analysis suggested that TC (odds ratio [ OR]=1.501, 95% confidence interval [ CI]: 1.275-1.767, P<0.01) and ALP ( OR=1.005, 95% CI: 1.003-1.006, P<0.01) were independent risk factors influencing patient response. The ROC curve analysis suggested worse prognosis for patients with TC≥5.415 mmol/L ( AUC: 0.727, 95% CI: 0.680-0.775, 63.8% sensitivity, 76.4% specificity). In addition, the UK-PBC risk score at 1 year of treatment was higher in the high-TC group (TC≥5.415 mmol/L) than that in the low-TC group (TC<5.415 mmol/L) ( P<0.05).

Conclusions

Hypercholesterolemia is an independent risk factor for poor response to UDCA in PBC patients. When the baseline TC is equal to or higher than 5.415 mmol/L, PBC patients have a relatively poor response to UDCA and poor prognosis.

Hepatoprotective agents in the management of intrahepatic cholestasis of pregnancy: current knowledge and prospects

Intrahepatic cholestasis of pregnancy (ICP) is characterized by unexplained distressing pruritus in the mother and poses significant risk to the fetus of perinatal mortality. Occurring in the second and third trimester, the serum bile acid and aminotransferase are usually elevated in ICP patients. Ursodeoxycholic acid (UDCA) is the first line drug for ICP but the effectiveness for hepatoprotection is to a certain extent. In ICP patients with severe liver damage, combination use of hepatoprotective agents with UDCA is not uncommon. Herein, we reviewed the current clinical evidence on application of hepatoprotective agents in ICP patients. The underlying physiological mechanisms and their therapeutic effect in clinical practice are summarized. The basic pharmacologic functions of these hepatoprotective medications include detoxification, anti-inflammation, antioxidation and hepatocyte membrane protection. These hepatoprotective agents have versatile therapeutic effects including anti-inflammation, antioxidative stress, elimination of free radicals, anti-steatohepatitis, anti-fibrosis and anti-cirrhosis. They are widely used in hepatitis, non-alcoholic fatty liver disease, drug induced liver injury and cholestasis. Evidence from limited clinical data in ICP patients demonstrate reliable effectiveness and safety of these medications. Currently there is still no consensus on the application of hepatoprotective agents in ICP pregnancies. Dynamic monitoring of liver biochemical parameters and fetal condition is still the key recommendation in the management of ICP pregnancies.

Prognostic scores in primary biliary cholangitis patients with advanced disease

BACKGROUND

Due to the chronic progressive disease characteristics of primary biliary cholangitis (PBC), patients with advanced PBC should not be ignored. Most prognostic score studies have focused on early stage PBC.

AIM

To compare the prognostic value of various risk scores in advanced PBC to help PBC patients obtain more monitoring and assessment.

METHODS

This study considered patients diagnosed with PBC during hospitalization between 2015 and 2021. The clinical stage was primarily middle and late, and patients usually took ursodeoxycholic acid (UDCA) after diagnosis. The discriminatory performance of the scores was assessed with concordance statistics at baseline and after 1 year of UDCA treatment. Telephone follow-up was conducted to analyze the course and disease-associated outcomes. The follow-up deadline was December 31, 2021. We compared the risk score indexes between those patients who reached a composite end point of death or liver transplantation (LT) and those who remained alive at the deadline. The combined performance of prognostic scores in estimating the risk of death or LT after 1 year of UDCA treatment was assessed using Cox regression analyses. Predictive accuracy was evaluated by comparing predicted and actual survival through Kaplan-Meier analyses.

RESULTS

We included 397 patients who were first diagnosed with PBC during hospitalization and received UDCA treatment; most disease stages were advanced. After an average of 6.4 ± 1.4 years of follow-up, 82 patients had died, and 4 patients had undergone LT. After receiving UDCA treatment for 1 year, the score with the best discrimination performance was the Mayo, with a concordance statistic of 0.740 (95% confidence interval: 0.690-0.791). The albumin-bilirubin, GLOBE, and Mayo scores tended to overestimate transplant-free survival. Comparing 7 years of calibration results showed that the Mayo score was the best model.

CONCLUSION

The Mayo, GLOBE, UK-PBC, and ALBI scores demonstrated comparable discriminating performance for advanced stage PBC. The Mayo score showed optimal discriminatory performance and excellent predictive accuracy.

The causal effect of bioavailable testosterone on primary biliary cholangitis in female patients: A Bidirectional Mendelian randomization analysis

BACKGROUND

Primary biliary cholangitis (PBC) primarily affects female in their 4th to 6th decade of life at which stage female's sex hormones change dramatically. Sex hormones have a wide range of effects on the liver and immune system. However, it remains unclear whether sex hormonal changes mediate the onset of PBC.

AIMS

This study investigated the causal effect between total testosterone (TT), bioavailable testosterone (BAT), sex hormone binding globulin (SHBG) in female and PBC using public GWAS summary data.

METHODS

Data on TT, BAT, SHBG in female were obtained from a previous study based on the UK Biobank. PBC GWAS summary data was obtained from a genome-wide meta-analysis. We used several methods to make the conclusion robust. Various sensitivity analyses had been conducted to assess the consistency of our findings.

RESULTS

Our Mendelian randomization analysis revealed that the genetically predicted BAT in female was positively associated with PBC and SHBG in female was negatively associated with PBC. The results obtained from different methods are similar, which proves the reliability of the results.

CONCLUSIONS

Our study supported a causal relationship of BAT and SHBG in female on PBC. To confirm the association between testosterone and PBC, more research should be conducted.

Clinical Outcomes and Validation of Ursodeoxycholic Acid Response Scores in Patients with Korean Primary Biliary Cholangitis: A Multicenter Cohort Study

Background/Aims

The ursodeoxycholic acid (UDCA) response score (URS) was developed to identify poor responders to UDCA before treatment, in order to offer timely and proactive intervention. However, validation of the URS in Asian population is warranted.

Methods

A total of 173 Asian patients diagnosed with primary biliary cholangitis (PBC) between 2007 and 2016 at seven academic institutions in Korea who started UDCA treatment were analyzed to validate the performance of URS. UDCA response was defined as an alkaline phosphatase level less than 1.67 times the upper limit of normal after 1-year of UDCA treatment. In addition, prognostic performance of URS for liver-related events, defined as newly developed hepatic decompensation or hepatocellular carcinoma was evaluated.

Results

After 1 year of UDCA treatment, 133 patients (76.9%) achieved UDCA response. UDCA response rate was 98.7% for those with URS ≥1.41 (n=76) and 58.8% for those with URS <1.41 (n=97). The area under the receiver operating characteristic curve of URS in predicting UDCA response was 0.84 (95% confidence interval, 0.78 to 0.88). During a median follow-up of 6.5 years, liver-related events developed in 18 patients (10.4%). Among 117 patients with PBC stage I-III by histological evaluation, the 5-year liver-related event-free survival rate differed according to the URS; 100% for URS ≥1.41 and 86.5% for URS <1.41 (p=0.005).

Conclusions

URS demonstrated good performance in predicting a UDCA treatment response in Asian PBC patients. In addition, the risk of liver-related events differed according to the URS for the PBC stage. Thus, URS can be used to predict the response and clinical outcome in patients with PBC.

Immunological factors in cirrhosis diseases from a bibliometric point of view

BACKGROUND

Cirrhosis results from persistent liver injury that leads to liver fibrosis. Immunological factors play important regulatory roles in the development and progression of cirrhosis. Bibliometrics is one of the most commonly used methods for systematic evaluation of a field of study. To date, there are no bibliometric studies on the role of immunological factors in cirrhosis.

AIM

To provide a comprehensive overview of the knowledge structure and research hotspots of immunological factors in cirrhosis.

METHODS

We retrieved publications related to immunological factors in cirrhosis between 2003 to 2022 from the Web of Science Core Collection database on December 7, 2022. The search strategy was TS = ((Liver Cirrhosis OR hepatic cirrhosis OR liver fibrosis) AND (Immunologic* Factor* OR Immune Factor* OR Immunomodulator* OR Biological Response Modifier* OR Biomodulator*)). Only original articles and reviews were included. A total of 2873 publications were analyzed using indicators of publication and citation metrics, countries, institutes, authors, journals, references, and keywords by CiteSpace and VOSviewer.

RESULTS

A total of 5104 authors from 1173 institutions across 51 countries published 2873 papers on cirrhosis and immunological factors in 281 journals. In the past 20 years, the increasing number of related annual publications and citations indicates that research on immunological factors in cirrhosis has become the focus of attention and has entered a period of accelerated development. The United States (781/27.18%), China (538/18.73%), and Germany (300/10.44%) were the leading countries in this field. Most of the top 10 authors were from the United States (4) and Germany (3), with Gershwin ME contributing the most related articles (42). World Journal of Gastroenterology was the most productive journal, whereas Hepatology was the most co-cited journal. Current research hotspots regarding immunological factors in cirrhosis include fibrosis, cirrhosis, inflammation, liver fibrosis, expression, hepatocellular carcinoma, activation, primary biliary cirrhosis, disease, and hepatic stellate cells. Burst keywords (e.g., epidemiology, gut microbiota, and pathways) represent research frontiers that have attracted the interest of researchers in recent years.

CONCLUSION

This bibliometric study comprehensively summarizes the research developments and directions of immunological factors in cirrhosis, providing new ideas for promoting scientific research and clinical applications.

Primary biliary cholangitis: Epidemiology, prognosis, and treatment

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease characterized by a destructive, small duct, and lymphocytic cholangitis, and marked by the presence of antimitochondrial antibodies. The incidence and prevalence of PBC vary widely in different regions and time periods, and although disproportionally more common among White non-Hispanic females, contemporary data show a higher prevalence in males and racial minorities than previously described. Outcomes largely depend on early recognition of the disease and prompt institution of treatment, which, in turn, are directly influenced by provider bias and socioeconomic factors. Ursodeoxycholic acid remains the initial treatment of choice for PBC, with obeticholic acid and fibrates (off-label therapy) reserved as add-on therapy for the management of inadequate responders or those with ursodeoxycholic acid intolerance. Novel and repurposed drugs are currently at different stages of clinical development not only for the treatment of PBC but also for its symptomatic management. Here, we summarize the most up-to-date data regarding the epidemiology, prognosis, and treatment of PBC, providing clinically useful information for its holistic management.

Setanaxib, a first-in-class selective NADPH oxidase 1/4 inhibitor for primary biliary cholangitis: A randomized, placebo-controlled, phase 2 trial

BACKGROUND

Primary biliary cholangitis (PBC) is a rare liver disease with significant unmet need for second-line/add-on treatments. Setanaxib, a NOX1/4 inhibitor, has shown anti-fibrotic effects in in vitro and animal studies. This phase 2, randomized, multicentre study investigated the efficacy and safety of setanaxib in patients with PBC.

METHODS

Patients with ≥6 months of ursodeoxycholic acid (UDCA) treatment were randomized 1:1:1 to oral setanaxib 400 mg once daily (OD), twice daily (BID), or placebo, in addition to UDCA for 24 weeks. Other inclusion criteria included alkaline phosphatase (ALP) ≥1.5 × ULN and gamma-glutamyl transferase (GGT) ≥1.5 × ULN. The primary endpoint was percentage change from baseline in GGT at Week 24; secondary endpoints included change from baseline in ALP, liver stiffness (LS; via transient elastography), fatigue at Week 24, and safety outcomes. p values compare setanaxib 400 mg BID and placebo groups.

RESULTS

Of patients randomized (setanaxib 400 mg OD and BID: 38, and 36; placebo: 37), 104/111 completed Week 24. Mean (standard deviation [SD]) change in GGT to Week 24 was -4.9% (59.6%) for setanaxib 400 mg OD, -19.0% (28.9%) for setanaxib 400 mg BID, and -8.4% (21.5%) for placebo; p = .31. Patients treated with setanaxib 400 mg OD and BID showed decreased serum ALP levels from baseline to Week 24 (p = .002: setanaxib BID versus placebo). Patients treated with setanaxib 400 mg OD and BID showed mean (SD) percentage increases in LS to Week 24 of 3.3% (35.0%) and 7.9% (43.7%), versus 10.1% (33.1%) for placebo (p = .65). Changes in mean (SD) PBC-40 fatigue domain scores to Week 24 were +0.3% (24.9%) for setanaxib 400 mg OD, -9.9% (19.8%) for setanaxib 400 mg BID and +2.4% (23.1%) for placebo, p = .027. Two patients (one placebo, one setanaxib 400 mg BID) experienced serious treatment-emergent adverse events, deemed unrelated to study drug.

CONCLUSIONS

The primary endpoint was not met. However, the secondary endpoints provide preliminary evidence for potential anti-cholestatic and anti-fibrotic effects in PBC, supporting the further evaluation of setanaxib in a future phase 2b/3 trial.

Plasma lipidomics of primary biliary cholangitis and its comparison with Sjögren's syndrome

Background

Abnormal lipid metabolism is common in patients with primary biliary cholangitis (PBC). PBC and Sjögren's syndrome (SS) frequently coexist in clinical practice; however, the lipid characteristics of both diseases are unknown. Therefore, we aimed to analyze the plasma lipid profiles of both diseases.

Methods

Plasma samples from 60 PBC patients, 30 SS patients, and 30 healthy controls (HC) were collected, and untargeted lipidomics was performed using ultrahigh-performance liquid chromatography high-resolution mass spectrometry. Potential lipid biomarkers were screened through an orthogonal projection to latent structure discriminant analysis and further evaluated using receiver operating characteristic (ROC) analysis.

Results

A total of 115 lipids were differentially upregulated in PBC patients compared with HC. Seventeen lipids were positively associated with the disease activity of PBC, and ROC analysis showed that all of these lipids could differentiate between ursodeoxycholic acid (UDCA) responders and UDCA non-responders. The top six lipids based on the area under the curve (AUC) values were glycerophosphocholine (PC) (16:0/16:0), PC (18:1/18:1), PC (42:2), PC (16:0/18:1), PC (17:1/14:0), and PC (15:0/18:1). In comparison with SS, 44 lipids were found to be differentially upregulated in PBC. Additionally, eight lipids were found to have a good diagnostic performance of PBC because of the AUC values of more than 0.9 when identified from SS and HC groups, which were lysophosphatidylcholines (LysoPC) (16:1), PC (16:0/16:0), PC (16:0/16:1), PC (16:1/20:4), PC (18:0/20:3), PC (18:1/20:2), PC (20:0/22:5), and PC (20:1/22:5).

Conclusion

Our study revealed differentially expressed lipid signatures in PBC compared with HC and SS. PC is the main lipid species associated with disease activity and the UDCA response in patients with PBC.

Unraveling the heterogeneity of cholangiocarcinoma and identifying biomarkers and therapeutic strategies with single-cell sequencing technology

Cholangiocarcinoma (CCA) is a common malignant tumor of the biliary tract that carries a high burden of morbidity and a poor prognosis. Due to the lack of precise diagnostic methods, many patients are often diagnosed at advanced stages of the disease. The current treatment options available are of varying efficacy, underscoring the urgency for the discovery of more effective biomarkers for early diagnosis and improved treatment. Recently, single-cell sequencing (SCS) technology has gained popularity in cancer research. This technology has the ability to analyze tumor tissues at the single-cell level, thus providing insights into the genomics and epigenetics of tumor cells. It also serves as a practical approach to study the mechanisms of cancer progression and to explore therapeutic strategies. In this review, we aim to assess the heterogeneity of CCA using single-cell sequencing technology, with the ultimate goal of identifying possible biomarkers and potential treatment targets.

Development of HPLC-CAD method for simultaneous quantification of nine related substances in ursodeoxycholic acid and identification of two unknown impurities by HPLC-Q-TOF-MS

Ursodeoxycholic acid has gained increasing attention due to its recent discovery of the preventive effect on SARS-CoV-2 infection. Ursodeoxycholic acid has been included in various pharmacopoeias as an old drug, and the latest European Pharmacopoeia lists nine potential related substances (impurities A~I). However, existing methods in pharmacopoeias and literature can only quantify up to five of these impurities simultaneously, and the sensitivity is inadequate, as the impurities are isomers or cholic acid analogues lacking chromophores. Herein, a novel gradient RP-HPLC method coupled to charged aerosol detection (CAD) was developed and validated for the simultaneous separation and quantification of the nine impurities in ursodeoxycholic acid. The method proved sensitive and allowed the quantification of the impurities as low as 0.02%. Relative correction factors of the nine impurities were all within the range of 0.8~1.2 in the gradient mode by optimizing chromatographic conditions and CAD parameters. In addition, this RP-HPLC method is fully compatible with LC-MS due to the volatile additives and high percentage of the organic phase, which can be directly used for the identification of impurities. The newly developed HPLC-CAD method was successfully applied to commercial bulk drug samples, and two unknown impurities were identified by HPLC-Q-TOF-MS. The effect of CAD parameters on the linearity and correction factors was also discussed in this study. Overall, the established HPLC-CAD method can improve the methods in current pharmacopoeias and literature and contributes to understanding the impurity profile for process improvement.

Biological synthesis of ursodeoxycholic acid

Ursodeoxycholic acid (UDCA) is a fundamental treatment drug for numerous hepatobiliary diseases that also has adjuvant therapeutic effects on certain cancers and neurological diseases. Chemical UDCA synthesis is environmentally unfriendly with low yields. Biological UDCA synthesis by free-enzyme catalysis or whole-cell synthesis using inexpensive and readily available chenodeoxycholic acid (CDCA), cholic acid (CA), or lithocholic acid (LCA) as substrates is being developed. The free enzyme-catalyzed one-pot, one-step/two-step method uses hydroxysteroid dehydrogenase (HSDH); whole-cell synthesis, mainly uses engineered bacteria (mainly Escherichia coli) expressing the relevant HSDHs. To further develop these methods, HSDHs with specific coenzyme dependence, high enzyme activity, good stability, and high substrate loading concentration, P450 monooxygenase with C-7 hydroxylation activity and engineered strain harboring HSDHs must be exploited.

Identification of AKR1B10 as a key gene in primary biliary cholangitis by integrated bioinformatics analysis and experimental validation

Background: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease that eventually progresses to cirrhosis and hepatocellular carcinoma (HCC) in the absence of proper treatment. However, Gene expression and molecular mechanisms involved in the pathogenesis of PBC have not been completely elucidated. Methods: Microarray expression profiling dataset GSE61260 was downloaded from the Gene Expression Omnibus (GEO) database. Data were normalized to screen differentially expressed genes (DEGs) using the limma package in R. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed. A protein-protein interaction (PPI) network was constructed to identify hub genes and an integrative regulatory network of transcriptional factor-DEG-microRNA was established. Gene Set Enrichment Analysis (GSEA) was used to analyze differences in biological states for groups with different expressions of aldo-keto reductase family 1 member B10 (AKR1B10). Immunohistochemistry (IHC) analysis was performed to validate the expression of hepatic AKR1B10 in patients with PBC. The association of hepatic AKR1B10 levels with clinical parameters was evaluated using one-way analysis of variance (ANOVA) and Pearson's correlation analysis. Results: This study identified 22 upregulated and 12 downregulated DEGs between patients with PBC and healthy controls. GO and KEGG analysis revealed that DEGs were mainly enriched in immune reactions. AKR1B10 was identified as a key gene and was further analyzed by screening out hub genes from the PPI network. GSEA analysis indicated that high expression of AKR1B10 might promote PBC to develop into HCC. Immunohistochemistry results verified the increased expression of hepatic AKR1B10 in patients with PBC and demonstrated its positive correlation with the severity of PBC. Conclusion: AKR1B10 was identified as a hub gene in PBC by integrated bioinformatics analysis and clinical validation. The increase of AKR1B10 expression in patients with PBC was associated with disease severity and might promote the progression of PBC to HCC.

Risk Factors and Prognosis of Carbapenem-Resistant Organism Colonization and Infection in Acute Cholangitis

Background

To identify the risk factors and prognosis of carbapenem-resistant organisms (CRO) in patients with acute cholangitis.

Methods

This retrospective observational study was conducted to explore the risk factors and prognosis of CRO infection in 503 acute cholangitis patients diagnosed between July 2013 and January 2022 at the First Affiliated Hospital of Chongqing Medical University, who were divided into a CRO group and non-CRO group based on the presence or absence of CRO. Univariate, multivariate analyses, and the proportional hazards model were used to compare the risk factors and prognosis of CRO suffering in patients with acute cholangitis.

Results

We identified 35 patients colonized with CRO from 503 acute cholangitis patients. In the multivariate analysis, tumor (OR=7.09, 95% CI=1.11-45.30, P=0.038) and chronic kidney disease (OR=8.70, 95% CI=2.11-35.88, P=0.003) were ascertained as the risk factors of the occurrence on CRO infection under the background of acute cholangitis. CRO infection was identified as an independent risk factor for acute cholangitis patient death (HR=5.147, 95% CI=1.475-17.595, P=0.01) by Cox proportional-hazards regression.

Conclusion

Tumor and chronic kidney disease may be risk factors for CRO infection. Patients diagnosed with acute cholangitis further infected with CRO had a poor prognosis and a more severe mortality. Active screening for CRO is expected to facilitate early prevention, diagnosis, and treatment of high-risk patients.

Greater Transplant-Free Survival in Patients Receiving Obeticholic Acid for Primary Biliary Cholangitis in a Clinical Trial Setting Compared to Real-World External Controls

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.

Role of intestinal flora in primary sclerosing cholangitis and its potential therapeutic value

Primary sclerosing cholangitis (PSC) is an autoimmune disease characterized by chronic cholestasis, a persistent inflammation of the bile ducts that leads to sclerotic occlusion and cholestasis. Gut microbes, consisting of microorganisms colonized in the human gut, play an important role in nutrient intake, metabolic homeostasis, immune regulation, and immune regulation; however, their presence might aid PSC development. Studies have found that gut-liver axis interactions also play an important role in the pathogenesis of PSC. Patients with PSC have considerably reduced intestinal flora diversity and increased abundance of potentially pathogenic bacteria. Dysbiosis of the intestinal flora leads to increased intestinal permeability, homing of intestinal lymphocytes, entry of bacteria and their associated metabolites, such as bile acids, into the liver, stimulation of hepatic immune activation, and promotion of PSC. Currently, PSC effective treatment is lacking. However, a number of studies have recently investigated the targeted modulation of gut microbes for the treatment of various liver diseases (alcoholic liver disease, metabolic fatty liver, cirrhosis, and autoimmune liver disease). In addition, antibiotics, fecal microbiota transplantation, and probiotics have been reported as successful PSC therapies as well as for the treatment of gut dysbiosis, suggesting their effectiveness for PSC treatment. Therefore, this review briefly summarizes the role of intestinal flora in PSC with the aim of providing new insights into PSC treatment.

The Clostridium Metabolite P-Cresol Sulfate Relieves Inflammation of Primary Biliary Cholangitis by Regulating Kupffer Cells

OBJECTIVE

To study the effect and mechanism of the Clostridium metabolite p-Cresol sulfate (PCS) in primary biliary cholangitis (PBC).

METHODS

Gas chromatography-mass spectrometry (GC-MS) was used to detect differences in tyrosine, phenylalanine, tryptophan, PCS, and p-Cresyl glucuronide (PCG) between the serum of PBC patients and healthy controls. In vivo experiments, mice were divided into the normal control, PBC group, and PBC tyrosine group. GC-MS was used to detect PCS and PCG. Serum and liver inflammatory factors were compared between groups along with the polarization of liver Kupffer cells. Additionally, PCS was cultured with normal bile duct epithelial cells and Kupffer cells, respectively. PCS-stimulated Kupffer cells were co-cultured with lipopolysaccharide-injured bile duct epithelial cells to detect changes in inflammatory factors.

RESULTS

Levels of tyrosine and phenylalanine were increased, but PCS level was reduced in PBC patients, with PCG showing a lower concentration distribution in both groups. PCS in PBC mice was also lower than those in normal control mice. After oral administration of tyrosine feed to PBC mice, PCS increased, liver inflammatory factors were decreased, and anti-inflammatory factors were increased. Furthermore, Kupffer cells in the liver polarized form M1 transitioned to M2. PCS can damage normal bile duct epithelial cells and suppress the immune response of Kupffer cells. But PCS protects bile duct epithelial cells damaged by LPS through Kupffer cells.

CONCLUSIONS

PCS produced by Clostridium-metabolized tyrosine reduced PBC inflammation, suggesting that intervention by food, or supplementation with PCS might represent an effective clinical strategy for treating PBC.

Endothelin receptor B enhances liver injury and pro-inflammatory responses by increasing G-protein-coupled receptor kinase-2 expression in primary biliary cholangitis

Severe diseases like cirrhosis and liver failure can be developed from primary biliary cholangitis (PBC). Endothelin-2 (EDN2) and endothelin receptor B (EDNRB) are related to the pathogenesis of PBC. However, the roles of EDN2 and EDNRB in PBC-related liver injury and inflammation along with molecular mechanisms are poorly defined. In this study, histopathologic alterations of liver tissues were assessed through hematoxylin-eosin staining. Alanine transaminase (ALT), alkaline phosphatase (ALP), aspartate transaminase (AST), and γ-Glutamyltranspetidase (GGT) (4 liver function indexes) serum levels were detected with corresponding activity assay kits. Also, we determined the levels of M2 subtype anti-mitochondrial antibody (AMA-M2), interferon-gamma (IFN-γ), and tumor-necrosis factor alpha (TNFα) in serum with ELISA assay. Later, RT-qPCR assay was used to measure the expression of genes at mRNA levels, while western blotting and immunohistochemical techniques were used to detect protein levels of genes. Our results showed that the liver tissues of PBC patients and mice presented with severe hepatocyte injury and inflammatory cell infiltration as well as destruction of intrahepatic small bile ducts. ALP, AST, ALT, GGT, AMA-M2, IFN-γ, and TNF-α serum levels were higher in PBC patients and mice. Besides, EDN2 and EDNRB were highly expressed in serums and livers of PBC patients and mice. EDNRB potentiated PBC-related liver injury and pro-inflammatory responses, as evidenced by observation of serious liver pathologic injury and increased serum levels of ALP, AST, ALT, AMA-M2, IFN-γ, and TNF-α in PBC mice following EDNRB overexpression. EDNRB overexpression or activation via its agonist IRL-1620 TFA triggered liver injury and pro-inflammatory responses, increased GRK2 expression and induced NF-κB expression and activation in wild-type mice. EDNRB knockdown or inhibition by Bosentan alleviated liver damage and inflammation, reduced GRK2 expression, and inhibited NF-κB in PBC mice. These findings suggested EDNRB loss or inhibition weakened liver injury and pro-inflammatory responses by down-regulating GRK2 and inhibiting the NF-κB pathway in PBC mice.

Incomplete response to ursodeoxycholic acid in primary biliary cholangitis: criteria, epidemiology, and possible mechanisms

INTRODUCTION

As a common autoimmune disease with the characteristic of early complication, primary biliary cholangitis (PBC) leads to an increasing number of mortalities among people with end-stage liver disease (ESLD) waiting for liver transplantation. Ursodeoxycholic acid (UDCA) is the only approved first-line medicine for PBC, and a good response to treatment could acquire an ideal prognosis. Patients with poor UDCA response usually have more adverse outcomes and worse survival, therefore, the management of this group become a major consideration.

AREAS COVERED

Due to the complexity of race and environment for PBC, different criteria for UDCA response exhibit various predictive performances. Factors affecting UDCA response conditions include gender, age, ethnicity, serum indicators, auto-antibodies, and autoimmune comorbidities, while no agreement has been reached. In this review, we mainly focus on cellular senescence, immune-mediated damage, and vitamin D deficiency as possible mechanisms for UDCA non-responders.

EXPERT OPINION

The pathogenesis of PBC has yet to be clarified. Immunology-related mechanisms and therapy targets ought to be the main effort made for further study. Irrespective of the response condition, UDCA is recommended for routine administration in all PBC patients without contraindication. Ongoing clinical trials of second-line and additional therapy exhibit promising prospects.

Prediction and evaluation of high-risk patients with primary biliary cholangitis receiving ursodeoxycholic acid therapy: an early criterion

BACKGROUND AND AIMS

Current treatment guidelines recommend ursodeoxycholic acid (UDCA) as the first-line treatment for new-diagnosed primary biliary cholangitis (PBC) patients. However, up to 40% patients are insensitive to UDCA monotherapy, and evaluation of UDCA response at 12 months may result in long period of ineffective treatment. We aimed to develop a new criterion to reliably identify non-response patients much earlier.

METHODS

Five hundred sixty-nine patients with an average of 59 months (Median: 53; IQR:32-79) follow-up periods were randomly divided into either the training (70%) or the validation cohort (30%). The efficiency of different combinations of total bilirubin (TBIL), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) threshold values to predict outcomes was assessed at 1, 3 or 6 month after the initiation of UDCA therapy. The endpoints were defined as adverse outcomes, including liver-related death, liver transplantation and complications of cirrhosis. Adverse outcome-free survival was compared using various published criteria and a proposed new criterion.

RESULTS

A new criterion of evaluating UDCA responses at 1 month was established as: ALP ≤ 2.5 × upper limit of normal (ULN) and AST ≤ 2 × ULN, and TBIL ≤ 1 × ULN (Xi'an criterion). The 5 year adverse outcome-free survival rate of UDCA responders, defined by Xi'an criterion, was 97%, which was significantly higher than that of those non-responders (64%). An accurate distinguishing high-risk patients' capacity of Xi'an criterion was confirmed in both early and late-stage PBC.

CONCLUSIONS

Xi'an criterion has a similar or even higher ability to distinguish high-risk PBC patients than other published criteria. Xi'an criterion can facilitate early identification of patients requiring new therapeutic approaches.

Efficacy and safety of pharmacological interventions for pruritus in primary biliary cholangitis: A systematic review and meta-analysis

Background and objective: Pruritus is a common complication in patients with primary biliary cholangitis (PBC). The pathogenesis is not clear, and also the precise therapeutic measures remain alluring. In order to systematically evaluate the efficacy and safety of drug interventions in the treatment of pruritus associated with PBC, this systemic review and meta-analysis was conducted.

Methods: The randomized controlled trials (RCTs) on drug interventions in the treatment of pruritus associated with primary cholangitis were searched in the electronic databases of PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov. Two researchers independently screened the literature, extracted and integrated the data, and assessed the bias risk of the selected literature, according to the Cochrane handbook. Finally, the STATA 15.0 software was used for the meta-analysis.

Results: A total of 23 RCTs involving 2,194 patients were studied, that included 12 pharmacological interventions. In terms of itching relief, compared with placebo, UDCA, methotrexate and GSK2330672 had a definite effect in improving pruritus (pruritus remission rate before and after treatment, p < 0.05). In terms of serum indexes, compared with placebo group, UDCA, OCA, rifampicin, cyclosporine, NGM282, seladelpar and colchicine may improve blood alkaline phosphatase (ALP) (p < 0.05), but only rifampicin showed low heterogeneity. UDCA, bezafibrate, OCA, rifampicin, NGM282 and others may improve blood γ-glutamyl transpeptidase (γ-GGT) (p < 0.05), but due to the high heterogeneity and the limitation of research samples, a clear conclusion cannot be drawn. In terms of adverse events, except high (>15 mg/kg/day) and low doses (<13 mg/kg/day) of UDCA increased the incidence of adverse events, there were no risk of increasing the incidence of adverse events compared with placebo (p > 0.05), and a moderate dose of UDCA (13–15 mg/kg/day) and malotilate (1,500 mg/day) may also help in reducing the incidence of adverse events (p < 0.05).

Conclusion: UDCA, methotrexate and GSK2330672 may relieve itching in patients with PBC, but there is a lack of robust evidence to support their effect on ALP or γ-GGT. Due to the heterogeneity in the published studies, based on the present review, we cannot explicitly recommend any specific drug for the treatment of PBC-related pruritus.

Systematic Review Registration:link-https://osf.io/2g8ya, identifier 10.17605/OSF.IO/2G8YA

Pretransplant Evaluation and Liver Transplantation Outcome in PBC Patients

Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic liver disease characterized by progressive cholangiocyte and bile duct destruction leading to fibrosis and finally to liver cirrhosis. The presence of disease-specific serological antimitochondrial antibody (AMA) together with elevated alkaline phosphatase (ALP) as a biomarker of cholestasis is sufficient for diagnosis. Ursodeoxycholic acid (UDCA) is the first treatment option for PBC. Up to 40% of patients have an incomplete response to therapy, and over time disease progresses to liver cirrhosis. Several risk scores are proposed for better evaluation of patients before and during treatment to stratify patients at increased risk of disease progression. GLOBE score and UK PBC risk score are used for the evaluation of UDCA treatment and Mayo risk score for transplant-free survival. Liver transplantation (LT) is the only treatment option for end-stage liver disease. More than 10 years after LT, 40% of patients experience recurrence of the disease. A liver biopsy is required to establish rPBC (recurrent primary biliary cholangitis). The only treatment option for rPBC is UDCA, and data show biochemical and clinical improvement, plus potential beneficial effects for use after transplantation for the prevention of rPBC development. Additional studies are required to assess the full impact of rPBC on graft and recipient survival and for treatment options for rPBC.

Potential mesenchymal stem cell therapeutics for treating primary biliary cholangitis: advances, challenges, and perspectives

Primary biliary cholangitis (PBC) is a cholestatic autoimmune liver disease characterized by the gradual destruction of small intrahepatic bile ducts that eventually leads to liver cirrhosis, failure, and even carcinoma. The treatment options for PBC are limited, and the main treatment choices are the US Food and Drug Administration–approved ursodeoxycholic acid and obeticholic acid. However, many patients fail to respond adequately to these drugs and the adverse effects frequently lead to low life quality. For patients with end-stage PBC, liver transplantation remains the only effective treatment. Given their low immunogenicity, prominent immunomodulation property, differentiation potential, and tissue maintenance capacity, mesenchymal stem cells (MSCs) are emerging as new options for treating liver diseases, including PBC. Accumulating evidence from basic research to clinical studies supports the positive effects of MSC-based therapy for treating PBC. In this review, we characterized the underlying roles and mechanisms of MSCs for treating liver diseases and highlight recent basic and clinical advances in MSC-based therapy for treating PBC. Finally, the current challenges and perspectives for MSC-based therapy in clinical application are discussed, which could help accelerate the application of MSCs in clinical practice, especially for refractory diseases such as PBC.

Network Proximity-Based Drug Repurposing Strategy for Early and Late Stages of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic, cholestatic, immune-mediated, and progressive liver disorder. Treatment to preventing the disease from advancing into later and irreversible stages is still an unmet clinical need. Accordingly, we set up a drug repurposing framework to find potential therapeutic agents targeting relevant pathways derived from an expanded pool of genes involved in different stages of PBC. Starting with updated human protein-protein interaction data and genes specifically involved in the early and late stages of PBC, a network medicine approach was used to provide a PBC "proximity" or "involvement" gene ranking using network diffusion algorithms and machine learning models. The top genes in the proximity ranking, when combined with the original PBC-related genes, resulted in a final dataset of the genes most involved in PBC disease. Finally, a drug repurposing strategy was implemented by mining and utilizing dedicated drug-gene interaction and druggable genome information knowledge bases (e.g., the DrugBank repository). We identified several potential drug candidates interacting with PBC pathways after performing an over-representation analysis on our initial 1121-seed gene list and the resulting disease-associated (algorithm-obtained) genes. The mechanism and potential therapeutic applications of such drugs were then thoroughly discussed, with a particular emphasis on different stages of PBC disease. We found that interleukin/EGFR/TNF-alpha inhibitors, branched-chain amino acids, geldanamycin, tauroursodeoxycholic acid, genistein, antioestrogens, curcumin, antineovascularisation agents, enzyme/protease inhibitors, and antirheumatic agents are promising drugs targeting distinct stages of PBC. We developed robust and transparent selection mechanisms for prioritizing already approved medicinal products or investigational products for repurposing based on recognized unmet medical needs in PBC, as well as solid preliminary data to achieve this goal.

Recent discoveries in microbiota dysbiosis, cholangiocytic factors, and models for studying the pathogenesis of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a cholangiopathy caused by genetic and microenvironmental changes, such as bile homeostasis disorders and microbiota dysbiosis. Therapeutic options are limited, and proven surveillance strategies are currently lacking. Clinically, PSC presents as alternating strictures and dilatations of biliary ducts, resulting in the typical “beaded” appearance seen on cholangiography. The pathogenesis of PSC is still unclear, but cholangiocytes play an essential role in disease development, wherein a reactive phenotype is caused by the secretion of neuroendocrine factors. The liver–gut axis is implicated in the pathogenesis of PSC owing to the dysbiosis of microbiota, but the underlying mechanism is still poorly understood. Alterations in cholangiocyte responses and related signalling pathways during PSC progression were elucidated by recent research, providing novel therapeutic targets. In this review, we summarise the currently known underlying mechanisms of PSC pathogenesis caused by the dysbiosis of microbiota and newly reported information regarding cholangiocytes in PSC. We also summarise recently reported in vitro and in vivo models for studying the pathogenesis of PSC.

The Role of Bile Acids in the Human Body and in the Development of Diseases

Bile acids are specific and quantitatively important organic components of bile, which are synthesized by hepatocytes from cholesterol and are involved in the osmotic process that ensures the outflow of bile. Bile acids include many varieties of amphipathic acid steroids. These are molecules that play a major role in the digestion of fats and the intestinal absorption of hydrophobic compounds and are also involved in the regulation of many functions of the liver, cholangiocytes, and extrahepatic tissues, acting essentially as hormones. The biological effects are realized through variable membrane or nuclear receptors. Hepatic synthesis, intestinal modifications, intestinal peristalsis and permeability, and receptor activity can affect the quantitative and qualitative bile acids composition significantly leading to extrahepatic pathologies. The complexity of bile acids receptors and the effects of cross-activations makes interpretation of the results of the studies rather difficult. In spite, this is a very perspective direction for pharmacology.

Cultured bear bile powder ameliorates acute liver injury in cholestatic mice via inhibition of hepatic inflammation and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Natural bear bile powder (NBBP) is a traditional Chinese medicine used for treating liver dysfunction. Cultured bear bile powder (CBBP), which is produced using biotransformation of chicken bile, acts as an appropriate substitute for NBBP when treating cholestatic liver injury.

AIM OF THE STUDY

To investigate the molecular mechanisms underlying the hepatoprotective effects of CBBP in an α-naphthylisothiocyanate (ANIT)-induced cholestatic mouse model.

MATERIALS AND METHODS

Cholestatic mice were pretreated with CBBP or NBBP via oral gavage once a day for two weeks. Their blood biochemistry and liver histopathology were then evaluated using standard protocols. Western blot analyses, real-time polymerase chain reaction, and immunohistochemistry were used to evaluate changes in the protein levels and gene expression profiles of factors associated with hepatic inflammation and apoptosis in cholestatic mice.

RESULTS

CBBP significantly decreased the serum indices of liver injury, and ameliorated neutrophil infiltration and hepatocyte necrosis within liver tissue of cholestatic mice. Expression of the inflammatory factors, such as tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1, and intercellular adhesion molecule 1, was significantly reduced in CBBP-treated cholestatic mice. Moreover, proteins involved in the toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B (TLR4/Myd88/NF-κB) signaling pathway, such as CD14, TLR4, Myd88, and NF-κB, that were increased in cholestatic mice, were downregulated by CBBP. Meanwhile, increased expression of the apoptosis-related proteins, caspase-3 and Bax, in cholestatic mice was reversed by CBBP treatment.

CONCLUSION

CBBP treatment alleviates ANIT-induced cholestasis and liver injury by reducing hepatocyte inflammation and apoptosis.

The HVEM-BTLA Immune Checkpoint Restrains Murine Chronic Cholestatic Liver Injury by Regulating the Gut Microbiota

The herpes virus entry mediator (HVEM) is an immune checkpoint molecule regulating immune response, but its role in tissue repair remains unclear. Here, we reported that HVEM deficiency aggravated hepatobiliary damage and compromised liver repair after 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced injury. A similar phenotype was observed in B and T lymphocyte attenuator (BTLA)-deficient mice. These were correlated with impairment of neutrophil accumulation in the liver after injury. The hepatic neutrophil accumulation was regulated by microbial-derived secondary bile acids. HVEM-deficient mice had reduced ability to deconjugate bile acids during DDC-feeding, suggesting a gut microbiota defect. Consistently, both HVEM and BTLA deficiency had dysregulated intestinal IgA responses targeting the gut microbes. These results suggest that the HVEM-BTLA signaling may restrain liver injury by regulating the gut microbiota.

Dexamethasone may affect the occurrence of parenteral nutrition-associated cholestasis in preterm neonates

INTRODUCTION

Glucocorticoids are currently used for the co-therapeutic management of autoimmune hepatitis and some cholestatic diseases. Thus far, we do not know the efficacy of glucocorticoids in the treatment of parenteral nutrition-associated cholestasis. We aimed to analyze whether the administration of late postnatal dexamethasone for treating bronchopulmonary dysplasia influence the occurrence of parenteral nutrition-associated cholestasis in preterm neonates.

METHODS

A retrospective study was conducted for 78 preterm neonates without major anomalies (gestational age was <30 weeks, and birthweight was ≤1000 g) hospitalized in a neonatal unit. Total and direct serum bilirubin levels were measured about every two weeks for all neonates. Data including the administration of dexamethasone, intravenous nutrition, and enteral feeding were collected by at least three audits.

RESULTS

A total of 15 preterm neonates were diagnosed with parenteral nutrition-associated cholestasis, and after stopping parenteral nutrition, the direct bilirubin value decreased to the normal level for no longer than 150 days. The prolonged duration of parenteral nutrition was a risk factor, and late postnatal dexamethasone treatment was a protective factor in reducing the incidence of parenteral nutrition-associated cholestasis.

CONCLUSION

Dexamethasone treatment may reduce the occurrence of parenteral nutrition-associated cholestasis in preterm neonates.

Comparative Evidence for Intrahepatic Cholestasis of Pregnancy Treatment With Traditional Chinese Medicine Therapy: A Network Meta-Analysis

Background: Intrahepatic cholestasis of pregnancy (ICP) seriously threatens the health of pregnant women and newborns. A various number of Chinese prescriptions and patent medicines combined with ursodeoxycholic acid (UDCA) are used for treating ICP in China. However, there are still many doubts in choosing the suitable therapeutic drugs for the treatment of ICP in clinical practice.

Methods: Several electronic databases, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBM), Wanfang, and VIP, were comprehensively searched from the database inception to February 22, 2021. Randomized controlled trials (RCTs) reporting the use of UDCA only, Chinese prescriptions plus UDCA, and patent medicine plus UDCA for the treatment of ICP were collected according to their inclusion and exclusion criteria. Cochrane Reviewers’ Handbook version 5.2 was applied for the risk assessment of the included trials. STATA 16.0 software was used for network meta-analysis (NMA). The pruritus score and the serum levels of total bile acid (TBA), alanine aminotransferase (ALT), and aspartate transaminase (AST) in ICP patients served as the primary outcomes. Moreover, this study had been registered in PROSPERO (https://www.crd.york.ac.uk/PROSPERO/#joinuppage), and the registration number is CRD42020188831.

Results: Thirty-eight RCTs comprising 3,841 patients meeting the inclusion criteria were included in the network meta-analysis. The NMA results showed that compared with UDCA used alone, Yinchenhao decoction (seven different Chinese prescriptions or patent medicines) plus UDCA dramatically alleviated the primary outcomes of ICP, including the pruritus score, as well as the serum levels of TBA, ALT, and AST. The NMA results showed that the optimal drug ratio for the treatment of ICP was different from the dosage ratio of traditional Yinchenhao decoction. Significantly, the intervention plan f (IP-f) group [the similar prescription of Yinchenhao decoction 2 (Artemisia capillaris Thunb >15 g, Gardenia >9 g, and Rhubarb <5 g) + UDCA] was the best therapeutics among the eight therapies.

Conclusion: Overall, the combined use of Chinese prescriptions or patent medicine with UDCA was generally better than UDCA used alone. The dose of IP-f might be a beneficial therapeutic method for the clinical medication of ICP.

Clinical Trail Registration:https://www.crd.york.ac.uk/, identifier CRD42020188831.

Environmental exposure as a risk-modifying factor in liver diseases: Knowns and unknowns

Liver diseases are considered to predominantly possess an inherited or xenobiotic etiology. However, inheritance drives the ability to appropriately adapt to environmental stressors, and disease is the culmination of a maladaptive response. Thus “pure” genetic and “pure” xenobiotic liver diseases are modified by each other and other factors, identified or unknown. The purpose of this review is to highlight the knowledgebase of environmental exposure as a potential risk modifying agent for the development of liver disease by other causes. This exercise is not to argue that all liver diseases have an environmental component, but to challenge the assumption that the current state of our knowledge is sufficient in all cases to conclusively dismiss this as a possibility. This review also discusses key new tools and approaches that will likely be critical to address this question in the future. Taken together, identifying the key gaps in our understanding is critical for the field to move forward, or at the very least to “know what we don't know.”

Primary Biliary Cholangitis: A Case of Underdiagnosis

Primary biliary cholangitis is a rare autoimmune cholestatic disease with a variable clinical course. Its etiopathogenesis has not been completely clarified. It predominantly affects women and often progresses to liver cirrhosis. It may be asymptomatic or symptomatic with hepatic or extrahepatic manifestations. If its diagnosis and treatment are made early, the progression to cirrhosis and liver failure can be prevented.

We describe a clinical case of a 63-year-old woman, with no history of hepatotoxic drugs, who presented an analytical pattern of cytocholestasis with more than one decade of evolution.

Mapping of de novo mutations in primary biliary cholangitis to a disease-specific co-expression network underlying homeostasis and metabolism

Primary biliary cholangitis (PBC) is an autoimmune disease involving dysregulation of a broad array of homeostatic and metabolic processes. Although considerable single-nucleotide polymorphisms have been unveiled, a large fraction of risk factors remains enigmatic. Candidate genes with rare mutations that tend to confer more deleterious effects need to be identified. To help pinpoint cellular and developmental mechanisms beyond common noncoding variants, we integrated whole exome sequencing with integrative network analysis to investigate genes harboring de novo mutations. Prominent convergence has been revealed on a network of disease-specific co-expression comprised of 55 genes associated with homeostasis and metabolism. The transcription factor MEF2D and the DNA repair gene PARP2 were highlighted as hub genes and identified to be up- and down-regulated, respectively, in peripheral blood data set. Enrichment analysis demonstrated altered expression of MEF2D and PARP2 may trigger a series of molecular and cellular processes with pivotal roles in PBC pathophysiology. Our study identified genes with de novo mutations in PBC and suggested a subset of genes in homeostasis and metabolism tend to act in synergy through converging on co-expression network, providing novel insights into the etiology of PBC and expanding the pool of molecular candidates for discovering clinically actionable biomarkers.