Chronic Cholestatic Liver Disease Research Articles

Mechanism of formation and significance of antimitochondrial autoantibodies in the pathogenesis of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic progressive liver disease associated with cholangiopathies. The detection of antimitochondrial autoantibodies (AMAs) plays an important role in the diagnosis of classical PBC. AMAs are formed against the antigenic component associated with the dihydrolipoyl transacetylase of pyruvate dehydrogenase complex (E2 PDC) localized on the inner membrane of mitochondria. The loss of immune tolerance of E2 PDC in PBC is thought to be the cause of the mechanism of AMA formation and immune-mediated destruction of biliary epithelial cells (BECs) of the small- and medium-sized intrahepatic bile ducts. E2 PDC is not only present in BECs, but is also abundant in the mitochondria of all nucleated cells. The question remains as to why E2 PDC of only small BECs is the target of autoimmune attack. There is no evidence that AMAs have a deleterious effect on BECs. New scientific data has emerged that explains the damage to BECs in PBC by the defect of the biliary bicarbonate (HCO3–) “umbrella” that protects BECs from the detergent action of bile acids under physiological conditions. Disruption of HCO3– production by BECs in PBC leads to changes in the pH of hepatic bile, accompanied by accumulation of bile acids in the small BECs. The detergent action of bile acids leads to damage of membrane structures of BECs and their apoptosis, development of ductulopenia, and intrahepatic cholestasis. For the first time, it has been suggested that under the influence of bile acids, the E2 PDC antigen may undergo conformational changes that alter its immunological properties. E2 PDC becomes a neoantigen that is recognized by the normal (“healthy”) immune system as a foreign antigen, leading to the production of AMAs. For the first time, the authors of this review provide an explanation for why only small BECs are damaged in PBC.

Tauroursodeoxycholic acid targets HSP90 to promote protein homeostasis and extends healthy lifespan.

As the elderly population expands, the pursuit of therapeutics to reduce morbidity and extend lifespan has become increasingly crucial. As an FDA-approved drug for chronic cholestatic liver diseases, tauroursodeoxycholic acid (TUDCA), a natural bile acid, offers additional health benefits beyond liver protection. Here, we show that TUDCA extends the lifespan and healthspan of C. elegans. Importantly, oral supplementation of TUDCA improves fitness in old mice, including clinically relevant phenotypes, exercise capacity and cognitive function. Consistently, TUDCA treatment drives broad transcriptional changes correlated with anti-aging characteristics. Mechanistically, we discover that TUDCA targets the chaperone HSP90 to promote its protein refolding activity. This collaboration further alleviates aging-induced endoplasmic reticulum (ER) stress and facilitates protein homeostasis, thus offering resistance to aging. In summary, our findings uncover new molecular links between an endogenous metabolite and protein homeostasis, and propose a novel anti-aging strategy that could improve both lifespan and healthspan.

Immunobiology of primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory progressive cholestatic liver disease. Genetic risk factors, presence of autoantibodies, the strong clinical link with inflammatory bowel disease (IBD), and associations with other autoimmune disorders all suggest a pivotal role for the immune system in PSC pathogenesis. In this review, we provide a comprehensive overview of recent immunobiology insights in PSC. A particular emphasis is given to immunological concepts such as tissue-residency and knowledge gained from novel technologies including single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST). This review of the immunobiological landscape of PSC covers major immune cell types known to be enriched in PSC-diseased livers as well as recently described cell types whose biliary localization and contribution to PSC immunopathogenesis remain incompletely described. Finally, we emphasize the importance of time and space in relation to PSC heterogeneity as a key consideration for future studies interrogating the role of the immune system in PSC.

Identification of microbial antigens in liver tissues involved in the pathogenesis of primary biliary cholangitis using 16S rRNA metagenome analysis.

Multiple factors are involved in the pathogenesis of primary biliary cholangitis (PBC), a chronic cholestatic liver disease, characterized by intrahepatic cholangiopathy. In particular, studies have suggested that environmental factors such as the presence of granulomas in the portal vein region are important for the development of PBC. This study aimed to comprehensively analyze and identify foreign-derived antigens in PBC liver tissue to confirm their involvement in PBC pathogenesis. Portal areas and hepatocyte regions were selectively dissected from formalin-fixed paraffin-embedded PBC liver tissue samples using the microlaser method, followed by total DNA extraction. We then validated whether the bacterial strains identified through 16S rRNA metagenomic analysis were detected in PBC liver tissues. The most frequently detected bacterial genera in the PBC liver tissue samples were Sphingomonas panacis, Providencia, and Cutibacterium. These bacterial genera were also detected in the other PBC samples. Validation for the detection of S. panacis, the most abundant genus, revealed polymerase chain reaction bands extracted from the portal areas of all samples. They were also more highly expressed than bands detected in the hepatocyte region. S. panacis antigen was specifically detected in the portal areas of PBC liver tissues. The introduction of foreign-derived antigens into the liver as an environmental factor could be a possible mechanism for the development of PBC.

Heritable Chronic Cholestatic Liver Diseases: A Review.

Chronic cholestasis due to heritable causes is usually diagnosed in childhood. However, many cases can present and survive into adulthood. The time course varies considerably depending on the underlying etiology. Laboratory data usually reveal elevated conjugated hyperbilirubinemia, alkaline phosphatase, and gamma-glutamyl transpeptidase. Patients may be asymptomatic; however, when present, the typical symptoms are pruritus, jaundice, fatigue, and alcoholic stools. The diagnostic methods and management required depend on the underlying etiology. The development of genome-wide associated studies has allowed the identification of specific genetic mutations related to the pathophysiology of cholestatic liver diseases. The aim of this review was to highlight the genetics, clinical pathophysiology, presentation, diagnosis, and treatment of heritable etiologies of chronic cholestatic liver disease.

Evaluation of patients with positive anti-mitochondiral antibody and normal alkaline phosphatase levels for primary biliary cholangitis.

Primary Biliary Cholangitis (PBC) is a chronic cholestatic liver disease typically diagnosed by elevated cholestatic liver enzymes and a positive anti-mitochondrial antibody (AMA) test. The clinical importance of AMA positivity in patients with normal cholestatic liver enzymes is unclear. The aim of this study was to determine the relationship between PBC and AMA positivity detected in individuals with normal cholestatic enzyme levels. The files of patients with AMA and/or AMA-M2 positivity between 2009 and 2018 and whose alkaline phosphatase (ALP) levels were below upper limit of normal (ULN) at initial admission were retrospectively analyzed. The ALP levels were normal in all patients. All patients had AMA positivity demonstrated by indirect immunofluorescence (IIF) or AMA-M2 positivity demonstrated by ELISA. A total of 16 patients underwent liver biopsy and seven (43.75%) showed changes consistent with those with PBC. A total of 12 patients were diagnosed with PBC and were treated and followed up with this diagnosis. People with AMA positivity and normal cholestasis enzyme levels are closely associated with PBC. Some of these patients were diagnosed with PBC as a result of biopsy and some were diagnosed by clinical and laboratory findings during follow-up.. The patients with an AMA titration of 1/20 were not associated with PBC. In our study, results similar to the studies confirmed by biopsies were obtained. In this regard, there is a need for prospective and retrospective studies with longer follow-up periods.

Forward genetics combined with unsupervised classifications identified zebrafish mutants affecting biliary system formation

Impaired formation of the biliary network can lead to congenital cholestatic liver diseases; however, the genes responsible for proper biliary system formation and maintenance have not been fully identified. Combining computational network structure analysis algorithms with a zebrafish forward genetic screen, we identified 24 new zebrafish mutants that display impaired intrahepatic biliary network formation. Complementation tests suggested these 24 mutations affect 24 different genes. We applied unsupervised clustering algorithms to unbiasedly classify the recovered mutants into three classes. Further computational analysis revealed that each of the recovered mutations in these three classes has a unique phenotype on node-subtype composition and distribution within the intrahepatic biliary network. In addition, we found most of the recovered mutations are viable. In those mutant fish, which are already good animal models to study chronic cholestatic liver diseases, the biliary network phenotypes persist into adulthood. Altogether, this study provides unique genetic and computational toolsets that advance our understanding of the molecular pathways leading to biliary system malformation and cholestatic liver diseases.

The potential of volatile organic compounds to diagnose primary sclerosing cholangitis

IntroductionPrimary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by progressive inflammation and fibrosis of the bile ducts. PSC is a complex disease of largely unknown aetiology with a strong association with inflammatory bowel disease (IBD). Diagnosis, especially at early stage, is difficult and to date there is no diagnostic biomarker. The present study aimed to assess the diagnostic potential of Volatile Organic Compounds (VOCs) in exhaled breath to detect (early) PSC in an IBD population. MethodsBreath samples were obtained from 16 PSC, 47 PSC with IBD, and 53 IBD patients during outpatient clinic visit. Breath sampling was performed using the ReCIVA breath sampler and subsequently analysed by gas chromatography mass spectrometry. Random Forest modelling was performed to find discriminatory VOCs and create a predictive model that was tested using an independent test set. ResultsThe final model to discriminate PSC patients with or without IBD versus IBD only patients included twenty VOCs and achieved a sensitivity, specificity, and area under the receiver operating curve on the test set of 77%, 83%, and 0.84 respectively. Three VOCs (isoprene, 2-octanone and undecane) together correlated significantly to the Amsterdam-Oxford score for PSC disease prognosis. A sensitivity analysis showed stable results across early stage PSC including those with normal alkaline phosphatase levels, as well as further progressed PSC. ConclusionThe present study demonstrates that exhaled breath can distinguish PSC cases from IBD and has potential as a non-invasive clinical breath test for (early) PSC. Impact and ImplicationsPrimary Sclerosing Cholangitis (PSC) is a complex chronic liver disease, which ultimately results in cirrhosis, liver failure, and death. Detection especially in early disease can be challenging, and therefore therapy typically starts when there is already some irreversible damage. The current study shows that metabolites in exhaled breath, so called Volatile Organic Compounds, hold promise to non-invasively detect PSC also at early stages.

CsHscB Derived from a Liver Fluke Clonorchis sinensis Ameliorates Cholestatic Hepatic Fibrosis in a Mouse Model of Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammatory fibrosis usually involving the whole biliary tree. However, there are very limited treatment options to treat this disease. Our previous study found a lipid-protein rCsHscB from a liver fluke - Clonorchis sinensis, which had full capacities of immune regulation. Therefore, we investigated the role of rCsHscB in a mouse model of sclerosing cholangitis induced by xenobiotic 3,5- diethoxycarbonyl-1,4-dihydrocollidine (DDC) to explore whether this protein had potential therapeutic value for PSC. Mice were fed 0.1% DDC for 4 weeks and treated with CsHscB (30 μg/mouse, intraperitoneal injection, once every 3 days); the control group was given an equal amount of PBS or CsHscB under normal diet conditions. All the mice were sacrificed at 4 weeks for the evaluation of biliary proliferation, fibrosis, and inflammation. rCsHscB treatment attenuated DDC-induced liver congestion and enlargement and significantly decreased the upregulation of serum AST and ALT levels. The administration of rCsHscB to DDC-fed mice significantly decreased cholangiocyte proliferation and pro-inflammatory cytokine production compared to mice fed with DDC alone. Also, rCsHscB treatment showed a decreased expression of α-SMA in the liver and other markers of liver fibrosis (Masson staining, Hydroxyproline content, and collagen deposit). More interestingly, DDC-fed mice treated with rCsHscB showed a significant up-regulation of PPAR-γ expression, which was similar to control mice, indicating the involvement of PPAR-γ signaling in the protective action of rCsHscB. Overall, our data show that rCsHscB attenuates the progression of cholestatic fibrosis induced by DDC and supports the potential for manipulating the parasite-derived molecule to treat certain immune-mediated disorders.

Механизм повреждения мелких холангиоцитов при первичном билиарном холангите

Primary biliary cholangitis (PBC) is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults. Damage to cholangiocytes triggers the development of intrahepatic cholestasis, which progresses to cirrhosis in the terminal stage of the disease. Accumulating data indicate that damage to biliary epithelial cells [(BECs), cholangiocytes] is most likely associated with the intracellular accumulation of bile acids, which have potent detergent properties and damaging effects on cell membranes. The mechanisms underlying uncontrolled bile acid intake into BECs in PBC are associated with pH change in the bile duct lumen, which is controlled by the bicarbonate (HCO3-) buffer system "biliary HCO3- umbrella". The impaired production and entry of HCO3- from BECs into the bile duct lumen is due to epigenetic changes in expression of the X-linked microRNA 506. Based on the growing body of knowledge on the molecular mechanisms of cholangiocyte damage in patients with PBC, we propose a hypothesis explaining the pathogenesis of the first morphologic (ductulopenia), immunologic (antimitochondrial autoantibodies) and clinical (weakness, malaise, rapid fatigue) signs of the disease in the asymptomatic stage. This review focuses on the consideration of these mechanisms.

Primary biliary cholangitis drug evaluation and regulatory approval: Where do we go from here?

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The management landscape was transformed 20 years ago with the advent of ursodeoxycholic acid. Up to 40% of patients do not, however, respond adequately to ursodeoxycholic acid and therefore still remain at risk of disease progression to cirrhosis. The introduction of obeticholic acid as a second-line therapy for patients failing ursodeoxycholic acid has improved outcomes for patients with PBC. There remains, however, a need for better treatment for patients at higher risk. The greatest threat facing our efforts to improve treatment in PBC is, paradoxically, the regulatory approval model providing conditional marketing authorization for new drugs based on biochemical markers on the condition that long-term, randomized placebo-controlled outcome trials are performed to confirm efficacy. As demonstrated by the COBALT confirmatory study with obeticholic acid, it is difficult to retain patients in the required follow-on confirmatory placebo-controlled PBC outcome trials when a licensed drug is commercially available. New PBC therapies in development, such as the peroxisome proliferator-activated receptor agonists, face even greater challenges in demonstrating outcome benefit through randomized placebo-controlled studies once following conditional marketing authorization, as there will be even more treatment options available. A recently published EMA Reflection Paper provides some guidance on the regulatory pathway to full approval but fails to recognize the importance of real-world data in providing evidence of outcome benefit in rare diseases. Here we explore the impact of the EMA reflection paper on PBC therapy and offer pragmatic solutions for generating evidence of long-term outcomes through real-world data collection.

Antagonistic effects of the cytotoxic molecules granzyme B and TRAIL in the immunopathogenesis of sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by biliary inflammation and fibrosis. We showed an elevated interferon γ response in patients with primary sclerosing cholangitis and in multidrug resistance protein 2-deficient ( Mdr2-/- ) mice developing sclerosing cholangitis. Interferon γ induced expression of the cytotoxic molecules granzyme B (GzmB) and TRAIL in hepatic lymphocytes and mediated liver fibrosis in sclerosing cholangitis. In patient samples and Mdr2-/- mice, we identified lymphocyte clusters with a cytotoxic gene expression profile using single-cell RNA-seq and cellular indexing of transcriptomes and epitopes by sequencing analyses combined with multi-parameter flow cytometry. CD8 + T cells and NK cells showed increased expression of GzmB and TRAIL in sclerosing cholangitis. Depletion of CD8 + T cells ameliorated disease severity in Mdr2-/- mice. By using Mdr2-/- × Gzmb-/- and Mdr2-/- × Tnfsf10-/- mice, we investigated the significance of GzmB and TRAIL for disease progression in sclerosing cholangitis. Interestingly, the lack of GzmB resulted in reduced cholangiocyte apoptosis, liver injury, and fibrosis. In contrast, sclerosing cholangitis was aggravated in the absence of TRAIL. This correlated with elevated GzmB and interferon γ expression by CD8 + T cells and NK cells enhanced T-cell survival, and increased apoptosis and expansion of cholangiocytes. GzmB induces apoptosis and fibrosis in sclerosing cholangitis, whereas TRAIL regulates inflammatory and cytotoxic immune responses, subsequently leading to reduced liver injury and fibrosis.

The effects of low-dose IL-2 on Th17/Treg cell imbalance in primary biliary cholangitis mouse models

Background/aimsPrimary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The imbalance of Th17/Treg cells has been reported in PBC patients. Low-dose IL-2 can alleviate disease severity through modulating CD4 + T cell subsets in patients with autoimmune diseases. Hence, the present study aimed to examine the effects and mechanism of low-dose IL-2 in PBC mouse models.MethodsPBC models were induced in female C57BL/6 mice by two immunizations with 2OA-BSA at two-week intervals, and poly I: C every three days. PBC mouse models were divided into the IL-2 treated and untreated groups and low-dose IL-2 was injected at three different time points. Th17 and Tregs were analyzed by flow cytometry, and the related cytokines were analyzed by ELISA. Liver histopathology was examined by H&E and immunohistochemical staining.ResultsTwelve weeks after modeling, the serum AMA was positive and the ALP was significantly increased in PBC mouse models (P<0.05). The pathology showed lymphocyte infiltration in the portal area, damage, and reactive proliferation of the small bile duct (P<0.05). The flow cytometric showed the imbalance of Th17/Treg cells in the liver of PBC mouse models, with decreased Treg cells, increased Th17 cells, and Th17/Treg ratio (P < 0.05). After the low-dose IL-2 intervention, biochemical index and liver pathologies showed improvement at 12 weeks. Besides, the imbalance of Th17 and Treg cells recovered. Public database mining showed that Th17 cell differentiation may contribute to poor response in PBC patients.ConclusionLow-dose IL-2 can significantly improve liver biochemistry and pathology by reversing the imbalance of Th17 and Treg cells, suggesting that it may be a potential therapeutic target for PBC.

Effect of modified Traditional Chinese Medicine external application in the treatment of pruritus in patients with chronic cholestatic liver disease

Effect of modified Traditional Chinese Medicine external application in the treatment of pruritus in patients with chronic cholestatic liver disease

P621 Safety and effectiveness of vedolizumab and ustekinumab in inflammatory bowel disease patients after liver transplantation for primary sclerosing cholangitis: results from an ECCO-confer case series

Abstract Background Primary sclerosing cholangitis (PSC) is a chronic progressive cholestatic liver disease often necessitating liver transplantation (LTX). Approximately 70% of PSC patients have a concomitant diagnosis of inflammatory bowel disease (IBD) and could need treatment with biological therapy on top of the immunosuppression to prevent transplant rejection. Vedolizumab (VDZ) and ustekinumab (UST), both agents with a favorable safety profile, are often used in this population despite lack of data concerning safety and effectiveness in the post-LTX setting. Methods A retrospective multicenter case series was performed as a part of the European Crohn's and Colitis Organisation [ECCO] Collaborative Network of Exceptionally Rare case reports [CONFER] project. Primary endpoints were clinical and endoscopic remission at week 52, occurrence of infectious complications, occurrence of malignancy, hospitalizations, and death after liver transplantation. Results In this retrospective study, 58 patients (male n= 34 (59%), median age 42 (interquartile range (IQR) 32-52) were included across 16 participating centers of which 24 (38%) were treated with UST and 40 (63%) with VDZ. Twelve patients (20%) were diagnosed with Crohn’s disease (CD), 44 (76%) with ulcerative colitis (UC), 2 (3%)- with unclassified IBD (IBD-U) and in 12 (20%) patients had an ileal pouch anal anastomosis (IPAA). Median disease duration was 16 years (IQR 13-26) and 33 (56%) had received biological therapy prior to LTX (33% anti-TNF, 11% VDZ, 5% UST). Median disease duration for PSC was 15.5 years (IQR 11-25) and median time since LTX was 6 years (IQR 4-10). Clinical remission, assessed according to physician global assessment, at week 52 was achieved in 44% of VDZ compared to 38% of UST treated patients (p=0.17), while endoscopic remission was seen in 17% of patients in the VDZ group versus 33% in the UST treated patients (p=0.87). Clinical effectiveness was similar across CD (respectively 33% and 20%), UC (33% and 37%) and IPAA patients (36% vs 60%). Infectious complications occurred in 21 patients (29%; 27% VDZ vs 33% UST) post LTX on biological therapy (p=0.66), malignancy occurred in 10 patients (14.1%, 12.8% VDZ vs 16.7% UST, p=0.66), hospitalizations in 32 (45%; 51% VDZ vs 34% UST, p=0.15), and death in 2 patients (3.4%; 2.1% VDZ vs 4.2% UST, p=0.66) (see table). Conclusion In IBD-PSC patients who underwent LTX both UST and VDZ show similar effectiveness with clinical remission rates of respectively 44% and 38% after 1 year. Safety profiles are similar although infectious complications and occurrence of malignancy remains an important concern in this patient group.

Primary Sclerosing Cholangitis: Diagnostic Criteria.

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intra- and/or extrahepatic bile ducts leading to the formation of multifocal strictures alternated to bile duct dilatations. The diagnosis of the most common subtype of the disease, the large duct PSC, is based on the presence of elevation of cholestatic indices, the association of typical cholangiographic findings assessed by magnetic resonance cholangiography and the exclusion of causes of secondary sclerosing cholangitis. Liver biopsy is not routinely applied for the diagnosis of large duct PSC but is mandatory in the case of suspicion of small duct PSC or overlap with autoimmune hepatitis.

Efficacy and safety of biologics in primary sclerosing cholangitis with inflammatory bowel disease: A systematic review and meta-analysis.

Primary sclerosing cholangitis (PSC) is an immune-mediated, chronic cholestatic liver disease. Currently, liver transplantation is the only established life-saving treatment. Several studies have evaluated the effect of different biologic therapies on PSC with inconclusive findings. We conducted a systematic review and meta-analysis to assess the effects of biologics in PSC and associated inflammatory bowel disease (IBD). MEDLINE, Scopus, and Embase were searched up to July 31, 2023, for studies reporting the effects of biologics in patients with PSC-IBD. Effects of biologic therapy on alkaline phosphatase, total bilirubin, ulcerative colitis response score, and adverse events were calculated and expressed as standardized difference of means (SMD), proportions, and 95% CI using a random-effects model. Six studies, including 411 PSC-IBD patients who received biologics, were included. Biologic treatment was associated with no change in alkaline phosphatase (SMD: 0.1, 95% CI: -0.07 -0.17, p=0.43), but a small and statistically significant increase in total bilirubin (SMD: 0.2, 95% CI: 0.05-0.35, p<0.01). 31.2% (95% CI: 23.8-39.7) of patients with IBD achieved endoscopic response, and there was a significant improvement in ulcerative colitis response score (SMD: -0.6,95% CI: -0.88 to 0.36, p<0.01). Furthermore, 17.6% (95% CI: 13.0-23.5) of patients experienced adverse events severe enough to discontinue therapy, and 29.9% (95% CI: 25.2-34.8) had a loss of response to biologics. Treatment of patients with PSC-IBD with biologics (vedolizumab, infliximab, and adalimumab) was not associated with improvement of biochemical markers of cholestasis. Biologics are effective in treating the colitis associated with PSC. Vedolizumab was associated with worsening liver enzymes in contrast to other biologics, a finding that warrants further study.

MR karakteristike primarnog sklerozirajućeg holangitisa - pregled skoring sistema zasnovanih na imidžing karakteristikama koji se koriste za procenu težine i prognoze

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease marked by inflammation, fibrosis, and narrowing of the bile ducts, leading to cholestasis. Magnetic resonance cholangiopancrea-tography (MRCP) is the gold standard for the diagnosis of PSC allowing insight into biliary duct changes. The typical presentation of PSC includes multifocal anular and short-segmental strictures alternating with normal or slightly dilatated biliary ducts. Besides cholangio-graphic findings, magnetic resonance (MR) allows the assessment of liver parenchymal changes which might indicate the severity of the disease. The scoring systems based on MR findings, such as the ANA-LI score, and new computer-based software analysis termed MRCP+, provide a prediction of the course of disease and identify high-risk patients. Thus, Mr with MRCP is a promising diagnostic tool for the integrative evaluation of PSC patients allowing not only initial diagnosis and detection of complications but also has prognostic significance.

Regulation of CD47 expression on CD14+ monocytes by interferon-α in PBC patients.

Primary biliary cholangitis (PBC) is a chronic intrahepatic cholestatic autoimmune liver disease characterized by inflammatory injury of small and medium-sized bile ducts in the liver. The pathogenesis of PBC has yet to be entirely understood. CD47/signal-regulatory protein alpha (SIRPα) is closely related to developing autoimmune diseases by promoting inflammatory response. However, the effect of CD47/SIRPα on inflammatory response in PBC patients is still unclear. We investigated the expression of CD47/SIRPα and the effect of inflammatory cytokines on the CD47 expression, analyzed potential autoantibodies against CD47 and the effect of anti-CD47 antibody on the inflammatory response in PBC, provided laboratory basis for the study of the pathogenesis and targets for non-invasive diagnosis and treatment on PBC. The expression levels of CD47 and SIRPα on peripheral blood mononuclear cells (PBMC) were measured in 14 patients with PBC (the PBC group) and 13 healthy subjects (the Control group) by flow cytometry (FCM). The PBMC derived from healthy subjects were stimulated with healthy subjects' serum, PBC patients' serum, IFN-α or TNF-α, and the CD47 expression level on CD14+ monocytes was detected by FCM. The level of serum anti-CD47 antibody or IFN-α in PBC patients and healthy subjects was analyzed by ELISA. FCM was used to examine the TNF-α expression level in CD14+ monocytes of healthy subjects stimulated with isotype control antibody, anti-CD47 antibody, LPS or LPS combined with CD47 antibody. The CD47 expression level on the CD14+ monocytes in PBC patients was statistically higher than that in the Control group (P<0.01). Compared with the Control group (PBMC+healthy serum), the CD47 expression on CD14+ monocyte stimulated with the PBC patients' serum (PBMC+PBC patients' serum) was increased (P<0.001); the CD47 expression on CD14+ monocyte stimulated with IFN-α (PBMC + IFN-α) increased gradually with the increased concentration of IFN-α (P<0.05). However, there was no similar trend on CD14+ monocyte stimulated with the TNF-α (PBMC+TNF-α) (P>0.05). The levels of serum anti-CD47 antibody and IFN-α in the PBC patients were higher than those in healthy subjects (P<0.05). The TNF-α expression level in CD14+ monocyte stimulated with the LPS (PBMC+LPS) or anti-CD47 antibody+LPS group (PBMC+LPS+anti-CD47 antibody) was significantly increased than that in the Control group (PBMC+isotype control antibody) (P<0.01 and P<0.001, respectively). The TNF-α expression level in CD14+ monocyte stimulated with the anti-CD47 antibody + LPS was higher than that with the LPS (P< 0.05). The CD47 may be related to the pathogenesis of PBC by inflammatory response. The CD47/SIRPα signal were imbalanced in PBC patients. The presence of serum anti-CD47 antibodies in PBC patients provides a laboratory basis for clinical diagnosis and treatment.

Current and future opportunities for the management of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a rare immune-mediated chronic cholestatic liver disease that can progress to liver fibrosis and, ultimately, cirrhosis if left untreated. Since the pathogenesis of PBC is not well understood, curative therapies have yet to be established. Ursodeoxycholic acid (UDCA), the standard of care treatment for PBC, has been proven to reduce disease progression and improve transplant-free survival. However, one third of patients have no response or partial biochemical response to UDCA and are at increased risk for disease progression. In such cases, second-line therapy with obeticholic acid (OCA) or peroxisomes proliferator-activated receptors (PPARs) should be considered in conjunction with UDCA. In this review article, we aim to provide an overview of the most recent data on PBC treatment in patients with inadequate response to UDCA, as well as novel therapies in the early stages of development.