MSC-derived exosomes attenuate hepatic fibrosis in primary sclerosing cholangitis through inhibition of Th17 differentiation

Primary sclerosing cholangitis(PSC)is an autoimmune cholangiopathy characterized by chronic inflammation of the biliary epithelium and periductal fibrosis,with no curative treatment available,and liver transplantation is inevitable for end-stage patients.Human placentalmesenchymal stem cell(hpMSC)-derived exosomes have demonstrated the ability to prevent fibrosis,inhibit collagen production and possess immunomodulatory properties in autoimmune liver disease.Here,we prepared hpMSC-derived exosomes(Exo^(MSC))and further investigated the anti-fibrotic effects and detailed mechanism on PSC based on Mdr2^(−/−)mice and multicellular organoids established from PSC patients.The results showed that Exo^(MSC) ameliorated liver fibrosis in Mdr2^(−/−)mice with significant collagen reduction in the preductal area where Th17 differentiation was inhibited as demonstrated by RNAseq analysis,and the percentage of CD4+IL-17A+T cells was reduced both in Exo^(MSC)-treated Mdr2^(−/−)mice(Mdr2^(−/−)-Exo)in vivo and Exo^(MSC)-treated Th17 differentiation progressed in vitro.Furthermore,Exo^(MSC) improved the hypersecretory phenotype and intercellular interactions in the hepatic Th17 microenvironment by regulating PERK/CHOP signaling as supported by multicellular organoids.Thus,our data demonstrate the antifibrosis effect of Exo^(MSC) in PSC disease by inhibiting Th17 differentiation,and ameliorating the Th17-induced microenvironment,indicating the promising potential therapeutic role of Exo^(MSC) in liver fibrosis of PSC or Th17-related diseases.

Autoimmune hepatitis and primary sclerosing cholangitis after direct-acting antiviral treatment for hepatitis C virus:A case report

BACKGROUND Chronic hepatitis C virus(HCV)infection is a major global health concern that leads to liver fibrosis,cirrhosis,and cancer.Regimens containing direct-acting antivirals(DAAs)have become the mainstay of HCV treatment,achieving a high sustained virological response(SVR)with minimal adverse events.CASE SUMMARY A 74-year-old woman with chronic HCV infection was treated with the DAAs ledipasvir,and sofosbuvir for 12 wk and achieved SVR.Twenty-four weeks after treatment completion,the liver enzyme and serum IgG levels increased,and antinuclear antibody became positive without HCV viremia,suggesting the development of autoimmune hepatitis(AIH).After liver biopsy indicated AIH,a definite AIH diagnosis was made and prednisolone was initiated.The treatment was effective,and the liver enzyme and serum IgG levels normalized.However,multiple strictures of the intrahepatic and extrahepatic bile ducts with dilatation of the peripheral bile ducts appeared on magnetic resonance cholangiopancreatography after 3 years of achieving SVR,which were consistent with primary sclerosing cholangitis.CONCLUSION The potential risk of developing autoimmune liver diseases after DAA treatment should be considered.

Limited validity of Mayo endoscopic subscore in ulcerative colitis with concomitant primary sclerosing cholangitis

BACKGROUND Ulcerative colitis(UC)with concomitant primary sclerosing cholangitis(PSC)represents a distinct disease entity(PSC-UC).Mayo endoscopic subscore(MES)is a standard tool for assessing disease activity in UC but its relevance in PSC-UC remains unclear.AIM To assess the accuracy of MES in UC and PSC-UC patients,we performed histological scoring using Nancy histological index(NHI).METHODS MES was assessed in 30 PSC-UC and 29 UC adult patients during endoscopy.NHI and inflammation were evaluated in biopsies from the cecum,rectum,and terminal ileum.In addition,perinuclear anti-neutrophil cytoplasmic antibodies,fecal calprotectin,body mass index,and other relevant clinical characteristics were collected.RESULTS The median MES and NHI were similar for UC patients(MES grade 2 and NHI grade 2 in the rectum)but were different for PSC-UC patients(MES grade 0 and NHI grade 2 in the cecum).There was a correlation between MES and NHI for UC patients(Spearman's r=0.40,P=0.029)but not for PSC-UC patients.Histopathological examination revealed persistent microscopic inflammation in 88%of PSC-UC patients with MES grade 0(46%of all PSC-UC patients).Moreover,MES overestimated the severity of active inflammation in an additional 11%of PSCUC patients.CONCLUSION MES insufficiently identifies microscopic inflammation in PSC-UC.This indicates that histological evaluation should become a routine procedure of the diagnostic and grading system in both PSC-UC and PSC.

Distinctive inflammatory bowel disease phenotype in primary sclerosing cholangitis

AIM:To review the current literature for the specificclinical characteristics of inflammatory bowel disease(IBD)associated with primary sclerosing cholangitis(PSC).METHODS:A systematical review for clinical characteristics of IBD in PSC was performed by conducting a broad search for"primary sclerosing cholangitis"in Pubmed."Clinical characteristics"were specified into five predefined subthemes:epidemiology of IBD in PSC,characteristics of IBD in PSC(i.e.,location,disease behavior),risk of colorectal cancer development,IBD recurrence and de novo disease after liver transplantation for PSC,and safety and complications after proctocolectomy with ileal pouchanal anastomosis.Papers were selected for inclusion based on their relevance to the subthemes,and were reviewed by two independent reviewers.Only full papers relevant to PSC-IBD were included.Additionally the references of recent reviews for PSC(<5 years old)were scrutinized for relevant articles.RESULTS:Initial literature search for PSC yielded 4704results.After careful review 65 papers,comprising a total of 11406 PSC-IBD patients,were selected and divided according to subtheme.Four manuscripts overlapped and were included in two subthemes.Prevalence of IBD in PSC shows a large variance,ranging from 46.5%to 98.7%with ulcerative colitis(UC)being the most common type(>75%).The highest IBD rates in PSC are found in papers reviewing both endoscopic and histological data for IBD diagnosis.Although IBD in PSC is found to be a quiescent disease,pancolitis occurs often,with rates varying from 35%to 95%.Both backwash ileitis and rectal sparing are observed infrequently.The development of dysplasia or colorectal carcinoma is increased in PSC-IBD;the cumulative 10 years risk varying between 0%and11%.Exacerbation of IBD is common after liver transplantation for PSC and de novo disease is seen in1.3%to 31.3%of PSC-IBD patients.The risk for development of pouchitis in PSC-IBD is found to besignificant,affecting 13.8%to 90%of the patients after proctocolectomy with ileo anal-pouch anastomosis.CONCLUSION:IBD in primary sclerosing cholangitis represents a distinct phenotype that differs from UC and Crohn’s disease and therefore requires specialized management.

Recurrence and rejection in liver transplantation for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic progressive inflammatory disease affecting the bile ducts, leading to f ibrosis and eventually cirrhosis in most patients. Its etiology is unknown and so far no effective medical therapy is available. Liver transplantation (LTX) is the only curative treatment and at present PSC is the main indication for LTX in the Scandinavian countries. Close to half of the PSC patients experience one or more episodes of acute cellular rejection (ACR) following transplantation and approximately 1/5 of the transplanted patients develop recurrent disease in the graft. In addition, some reports indicate that ACR early after LTX for PSC can infl uence the risk for recurrent disease. For these important post-transplantation entities affecting PSC patients, we have reviewed the current literature on epidemiology, pathogenesis, treatment and the possible infl uence of rejection on the risk of recurrent disease in the allograft.

Primary sclerosing cholangitis as an independent risk factor for colorectal cancer in the context of inflammatory bowel disease: A review of the literature

To examine and evaluate recent evidence regarding the epidemiology, pathogenesis and management of colorectal cancer(CRC) development in inflammatory bowel disease(IBD)-primary sclerosing cholangitis(PSC) patients. Using the PubMed database, a literature search was conducted for relevant articles in English from the past 10 years. Relevant studies investigating PSC as a risk factor for CRC in IBD in the context of incidence and prevalence, pathogenesis, prevention and prognosis were included in this review. Recent evidence increasingly points to PSC as a significant risk factor in the development of CRC in patients with concomitant IBD. PSC may be an important risk factor for CRC in different populations worldwide. The mechanism for this increase in risk is still unclear. The efficacy of UDCA as a chemopreventive agent remains controversial. Liver transplantation does not halt the development of CRC, although there is not enough evidence to suggest that it is associated with increased incidence of CRC. While routine colonoscopic surveillance should be performed in patients with concurrent PSC and IBD, more high-level evidence is required to support the benefits of the procedure. While many new developments have taken place in the last decade, the pathogenesis and optimal management of CRC development in IBD-PSC patients remain unclear.

Update on inflammatory bowel disease in patients with primary sclerosing cholangitis

Patients with primary sclerosing cholangitis(PSC) complicated by inflammatory bowel disease(IBD) represent a distinct subset of patients with unique characteristics,which have serious clinical implications.The aim of this literature review was to shed light to the obscure clinical and molecular aspects of the two diseases combined utilizing current data available and putting issues of diagnosis and treatment into perspective.The prevalence of IBD,mainly ulcerative colitis in PSC patients is estimated to be 21%-80%,dependent on screening programs and nationality.PSC-associated colitis is likely to be extensive,characterized by rectal sparing,backwash ileitis,and generally mild symptoms.It is also more likely to progress to colorectal malignancy,making it imperative for clinicians to maintain a high level of suspicion when tackling PSC patients.There is no optimal surveillance strategy but current guidelines advocate that colonoscopy is necessary at the time of PSC diagnosis with annual endoscopic follow-up.Random biopsies have been criticized and a shift towards targeted biopsies using chromoendoscopy,laser endomicroscopy and narrow-band imaging has been noted.Techniques directed towards genetic mutations instead of histological abnormalities hold promise for easier,more accurate diagnosis of dysplastic lesions.Chemopreventive measures against colorectal cancer have been sought in these patients.Ursodeoxycholic acid seemed promising at first but subsequent studies yielded conflicting results showing anticarcinogenic effects in low doses(8-15 mg/kg per day) and carcinogenic properties in high doses(15-30 mg/kg per day).

Distinct gut microbiota profiles in patients with primary sclerosing cholangitis and ulcerative colitis

To characterize the gut bacterial microbiota of patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). METHODSStool samples were collected and relevant clinical data obtained from 106 study participants, 43 PSC patients with (n = 32) or without (n = 11) concomitant inflammatory bowel disease, 32 UC patients, and 31 healthy controls. The V3 and V4 regions of the 16S ribosomal RNA gene were sequenced on Illumina MiSeq platform to cover low taxonomic levels. Data were further processed in QIIME employing MaAsLin and LEfSe tools for analysis of the output data. RESULTSMicrobial profiles in both PSC and UC were characterized by low bacterial diversity and significant change in global microbial composition. Rothia, Enterococcus, Streptococcus, Veillonella, and three other genera were markedly overrepresented in PSC regardless of concomitant inflammatory bowel disease (IBD). Rothia, Veillonella and Streptococcus were tracked to the species level to identify Rothia mucilaginosa, Streptococcus infantus, S. alactolyticus, and S. equi along with Veillonella parvula and V. dispar. PSC was further characterized by decreased abundance of Adlercreutzia equolifaciens and Prevotella copri. Decrease in genus Phascolarctobacterium was linked to presence of colonic inflammation regardless of IBD phenotype. Akkermansia muciniphila, Butyricicoccus pullicaecorum and Clostridium colinum were decreased in UC along with genus Roseburia. Low levels of serum albumin were significantly correlated with enrichment of order Actinomycetales. CONCLUSIONPSC is associated with specific gut microbes independently of concomitant IBD and several bacterial taxa clearly distinguish IBD phenotypes (PSC-IBD and UC).

Inflammatory bowel disease of primary sclerosing cholangitis:A distinct entity?

This is a review of the characteristic findings of inflammatory bowel disease(IBD)associated with primary sclerosing cholangitis(PSC)and their usefulness in the diagnosis of sclerosing cholangitis.PSC is a chronic inflammatory disease characterized by idiopathic fibrous obstruction and is frequently associated with IBD.IBDassociated with PSC(PSC-IBD)shows an increased incidence of pancolitis,mild symptoms,and colorectal malignancy.Although an increased incidence of pancolitis is a characteristic finding,some cases are endoscopically diagnosed as right-sided ulcerative colitis.Pathological studies have revealed that inflammation occurs more frequently in the right colon than the left colon.The frequency of rectal sparing and backwash ileitis should be investigated in a future study based on the same definition.The cholangiographic findings of immunoglobulin G4-related sclerosing cholangitis(IgG4-SC)are similar to those of PSC.The rare association between IBD and IgG4-SC and the unique characteristics of PSC-IBD are useful findings for distinguishing PSC from IgG4-SC.

Primary sclerosing cholangitis, autoimmune hepatitis and overlap syndromes in inflammatory bowel disease

Primary sclerosing cholangitis （PSC） is a chronic progressive disorder of unknown aetiology characterised by chronic inflammation and stricture formation of the biliary tree. Symptoms include itch and lethargy and in advanced cases cholangitis and end-stage liver disease, however increasing numbers of asymptomatic individuals are being identified. The disease is rare in the general population but is strongly associated with inflammatory bowel disease （IBD） affecting up to 5% of patients with Ulcerative Colitis, with a slightly lower prevalence （up to 3.6%） in Crohns disease. The strength of this association means that the vast majority （ 〉 90%） of patients with PSC also have IBD, although many may have only mild gastro-intestinal symptoms. Usually IBD presents before PSC, although vice-versa can occur and the onset of both conditions can be separated in some cases by many years. Mean age of diagnosis of PSC is in the fitch decade of life with a strong male predominance. Risk is increased in those with a family history of PSC, suggesting a genetic predisposition and the disease is almost exclusive to non-smokers. The ulcerative colitis associated with PSC is characteristically mild, runs a quiescent course, is associated with rectal sparing, more severe right sided disease, backwash ilieitis and has a high risk of pouchitis post-colectomy. Most worrisome is the high risk of colorectal malignancy which necessitates routine colonoscopic surveillance. Cholangiocarcinoma is also a frequent complication of PSC with a 10%-15% lifetime risk of developing this condition. Treatment with high dose ursodeoxycholic acid offers some chemoprotective effects against colorectal malignancy and may decrease symptoms, biochemical and histological progression of liver disease. Small duct PSC patients characteristically have normal cholangiography, and liver biopsy is required for diagnosis, it appears to have a more favourable prognosis. Autoimmune Hepatitis （AIH） is also more prevalent in patients with IBD, with up to 16% of patients with Autoimmune Hepatitis also having ulcerative colitis. A small subgroup of patients have a AIH-PSC overlap syndrome and the management of these patients depends on liver histology, serum IgM levels, autoantibodies, degree of biochemical cholestasis and cholangiography as some of these patients may respond to immunosupression.

Disease activity and cancer risk in inflammatory bowel disease associated with primary sclerosing cholangitis

AIM: To investigate the phenotype of inflammatory bowel disease associated with primary sclerosing cholangitis (PSC-IBD). METHODS: Data from 75 PSC-IBD patients evaluated in our tertiary center between 1963 and 2006 were collected and compared to 150 IBD patients without PSC, matched for sex, birth date, IBD diagnosis date and initial disease location regarding ileal, different colonic segments, and rectum, respectively. RESULTS: While PSC-IBD patients received more 5-aminosalicylates (8.7 years/patient vs 2.9 years/ patient, P < 0.001), they required less immuno-suppressors (24% vs 46% at 10 years; P < 0.001) and less intestinal resection (10% vs 44% at 10 years, P < 0.001). The 25-year cumulative rate of colectomy was 25.1% in PSC-IBD and 37.3% in controls (P = 0.004). The 25-year cumulative rate of colorectal cancer was 23.4% in PSC-IBD vs 0% in controls (P = 0.002). PSC was the only independent risk factor for the development of colorectal cancer (OR = 10.8; 95% CI, 3.7-31.3). Overall survival rate without liver transplantation was reduced in PSC-IBD patients (67% vs 91% in controls at 25 years, P = 0.001).CONCLUSION: This study confirms that patients with PSC-IBD have a particular disease phenotype independent of the initial disease location. Although their disease is less active and they use more 5-aminosalicylates, they present a higher risk of colorectal cancer.

Concurrent systemic AA amyloidosis can discriminate primary sclerosing cholangitis from IgG4-associated cholangitis

Chronic hepatobiliary inflammatory diseases are not widely acknowledged as underlying disorders of systemic AA amyloidosis,except epidemic schistosomiasis.Among them,primary sclerosing cholangitis (PSC) might initiate amyloid A protein deposition in diverse tissues,giving rise to systemic amyloidosis,due to a progressive and unresolved inflammatory process,and its possible association with inflammatory bowel diseases.Nevertheless,only one such case has been reported in the literature to date.We report a 69-year-old Japanese woman with cirrhosis who was diagnosed with PSC complicated with systemic AA amyloidosis,without any evidence of other inflammatory disorders.As a result of cholestasis in conjunction with biliary strictures and increased serum IgG4,the presence of IgG4 + plasma cells was examined systemically,resulting in unexpected documentation of Congo-red-positive amyloid deposits,but not IgG4 + plasma cells,in the liver,stomach and salivary glands.Elevated serum IgG4 is the hallmark of IgG4-related disease,including IgG4-associated cholangitis,but it has also been demonstrated in certain patients with PSC.Amyloid A deposits in multiple organs associated with an indolent clinical course that progresses over many years might have a diagnostic value in discriminating PSC from IgG4-associated cholangitis.

Gut microbiome in primary sclerosing cholangitis:A review

Primary sclerosing cholangitis(PSC)is a chronic cholestatic liver disease characterized by biliary inflammation and stricturing.Exploration of the pathogenesis of PSC in light of its association with inflammatory bowel disease(IBD)and the“gut-liver”axis is an emerging area of interest.A growing number of studies have begun to elucidate the role of the gut microbiota,its metabolites and its influence on host immune responses in the development of PSC and PSCIBD.Studies of the fecal microbiota have highlighted enriched levels of certain species,including Veillonella,Streptococcus and Enterococcus,among others.A heightened immune response to enteric dysbiosis and bacterial translocation have also been implicated.For example,Klebsiella pneumoniae strains derived from gnotobiotic mice transplanted with PSC-IBD microbiota were found to induce pore formation in human intestinal epithelial cells and enhanced Th17 responses.Gut microbes have additionally been hypothesized to be implicated in PSC pathogenesis through their role in the synthesis of various metabolites,including bile acids(BAs),which function as signaling molecules with important gut and hepatic effects.An expanded knowledge of the gut microbiome as it relates to PSC offers critical insight into the development of microbe-altering therapeutic interventions,such as antibiotics,nutritional interventions and fecal microbial transplantation.Some of these have already shown some preliminary evidence of benefit.Despite exciting progress in the field,much work remains to be done;areas that are particularly lacking include functional characterization of the microbiome and examination of pediatric populations.In this review,we summarize studies that have investigated the microbiome in PSC and PSC-IBD as well as putative mechanisms,including the potential role of metabolites,such as BAs.We then briefly review the evidence for interventions with microbe-altering properties for treating PSC.

Genetic epidemiology of primary sclerosing cholangitis

The aetiology of primary sclerosing cholangitis (PSC) is not known. A more than 80-fold increased risk of PSC among first-degree relatives emphasizes the importance of genetic factors. Genetic associations within the human leukocyte antigen (HLA) complex on chromosome 6p21 were detected in PSC 25 years ago. Subsequent studies have substantiated beyond doubt that one or more genetic variants located within this genetic region are important. The true identities of these variants,however,remain to be identified. Several candidate genes at other chromosomal loci have also been investigated. However,according to strict criteria for what may be denominated a susceptibility gene in complex diseases,no such gene exists for PSC today. This review summarises present knowledge on the genetic susceptibility to PSC,as well as genetic associations with disease progression and clinical subsets of particular interest (inflammatory bowel disease and cholangiocarcinoma).

Primary sclerosing cholangitis-What is the difference between east and west?

Primary sclerosing cholangitis （PSC） is a chronic, progressive, cholestatic liver disease characterized by inflammation and fibrotic obliteration of the hepatic biliary tree. It is commonly associated with inflammatory bowel disease （IBD）. A number of complications can occur which require special consideration, the most important of which is the development of cholangiocellular carcinoma （CCC）. Unfortunately, no medical therapy is currently available for the underlying liver disease. Liver transplantation is an effective, life-extending option for patients with advanced PSC. Geographical variations between East and West include a second peak for age with a lower association with IBD in a .lapanese population and female predominance in a lone study from Turkey. The clinical and biochemical Mayo criteria may not be universally applicable, as different patients show variations regarding the initial presentation and natural course of the disease, Directing research towards explaining these geographical differences and understanding the pathogenesis of PSC is required in order to develop better therapies for this devastating disease.

Role of endoscopy in the management of primary sclerosing cholangitis

Primary sclerosing cholangitis(PSC) is a rare but prominent fibroinflammatory cholangiopathy which can affect individuals of essentially any age. It carries a median survival of 15-20 years, regardless of age at diagnosis, and is a foremost risk factor for cholangiocarcinoma. Given the chronic and progressive nature of PSC, its inherent risk for biliary tract and other complications, and the paucity of effective pharmacotherapies, endoscopy plays a major role in the care of many patients with this disorder. In this review, we discuss the endoscopic management of PSC, including established and evolving approaches to the diagnosis and treatment of its benign as well as malignant sequelae. Owing to the rarity of PSC and dearth of high-quality evidence, we propose pragmatic approaches based on both currently available data and expert opinion.

Primary sclerosing cholangitis in Turkish patients:characteristic features and prognosis

BACKGROUND:Primary sclerosing cholangitis(PSC)is a chronic cholestatic liver disease characterized by destruction and fibrosis of the bile ducts.This study aimed to demonstrate the hepatic and extrahepatic characteristic findings and prognostic outcomes of Turkish patients with PSC. METHODS:The medical records of 35 consecutive patients with PSC from January 1988 to June 2007 were recorded prospectively.From the time of diagnosis,clinical features and laboratory data were collected. RESULTS:The mean age of the 35 patients was 41.69 years (range 15-80 years)at the time of diagnosis;14(40%)were female,and 21(60%)were male.The mean duration of follow-up was 58.86 months(1-180 months).Twenty(57.1%) of the patients with PSC were asymptomatic and 22(62.9%) had inflammatory bowel disease.At the time of diagnosis, 20(57.1%)of the patients had both intra-and extra-hepatic PSC.Twenty-one(60%)of the patients,who had undergone ERCP for stent placement,had dominant bile duct stenosis. Cholangiocarcinoma was found in 2(5.7%)of the patients and cirrhosis was detected in 7(20%);5(14.3%)underwent liver transplantation.The median follow-up time after liver transplantation was 23 months and all are still alive.Six (17.1%)patients died. CONCLUSIONS:PSC has a clinical course varied from advanced liver disease requiring liver transplantation within a short time to being asymptomatic for decades. The prognosis of Turkish patients with PSC is also disappointing as described in other studies.

Review of primary sclerosing cholangitis with increased IgG4 levels

Primary sclerosing cholangitis(PSC) is a chronic progressive liver disease. Subtypes of PSC have been described, most recently PSC with elevated serum and/or tissue IgG4 subclass. We aim to summarise the clinical phenotype,disease associations, differential diagnosis, response to therapy and pathogenic mechanisms underlying PSC-high IgG4 subtype. We reviewed Pub Med,MEDLINE and Embase with the search terms "primary sclerosing cholangitis","IgG4", and "IgG4-related sclerosing cholangitis(IgG4-SC)". Elevated serum IgG4 are found in up-to one-quarter, and abundant IgG4-plasma cell infiltrates in the liver and bile ducts are found in up-to one-fifth of PSC patients. This group have a distinct clinical phenotype, with some studies reporting a more aggressive course of liver and associated inflammatory bowel disease, compared to PSCnormal IgG4 and the disease mimic IgG4-SC. Distinguishing PSC-high IgG4 from IgG4-SC remains challenging, requiring careful assessment of clinical features,organ involvement and tissue morphology. Calculation of serum IgG4:IgG1 ratios and use of a novel IgG4:IgG RNA ratio have been reported to have excellent specificity to distinguish IgG4-SC and PSC-high IgG4 but require validation in larger cohorts. A role for corticosteroid therapy in PSC-high IgG4 remains unanswered, with concerns of increased toxicity and lack of outcome data. The immunological drivers underlying prominent IgG4 antibodies in PSC are incompletely defined. An association with PSC-high IgG4 and HLA class-II haplotypes(B*07, DRB1*15), T-helper2 and T-regulatory cytokines(IL4, IL10,IL13) and chemokines(CCL1, CCR8) have been described. PSC-high IgG4 have a distinct clinical phenotype and need careful discrimination from IgG4-SC,although response to immunosuppressive treatments and long-term outcome remains unresolved. The presence of IgG4 likely represents chronic activation to persistent antigenic exposure in genetically predisposed individuals.

Gut barrier failure biomarkers are associated with poor disease outcome in patients with primary sclerosing cholangitis

To assess the prevalence of a panel of serologic markers that reflect gut barrier dysfunction in a mixed cohort of pediatric and adult primary sclerosing cholangitis (PSC) patients. METHODSSera of 67 PSC patients [median age (range): 32 (5-79) years, concomitant IBD: 67% and cirrhosis: 20%] were assayed for the presence of antibodies against to F-actin (AAA IgA/IgG) and gliadin (AGA IgA/IgG)] and for serum level of intestinal fatty acid-binding protein (I-FABP) by ELISA. Markers of lipopolysaccharide (LPS) exposure [LPS binding protein (LBP)] and various anti-microbial antibodies [anti-OMP Plus IgA and endotoxin core IgA antibody (EndoCAb)] were also determined. Poor disease outcome was defined as orthotopic liver transplantation and/or liver-related death during the follow-up [median: 99 (14-106) mo]. One hundred and fifty-three healthy subjects (HCONT) and 172 ulcerative colitis (UC) patients were the controls. RESULTSA total of 28.4%, 28.0%, 9% and 20.9% of PSC patients were positive for AAA IgA, AAA IgG, AGA IgA and AGA IgG, respectively. Frequencies of AAA IgA and AAA IgG (P < 0.001, for both) and AGA IgG (P = 0.01, for both) but not AGA IgA were significantly higher compared to both of the HCONT and the UC groups. In survival analysis, AAA IgA-positivity was revealed as an independent predictor of poor disease outcome after adjusting either for the presence of cirrhosis [HR = 5.15 (1.27-20.86), P = 0.022 or for the Mayo risk score (HR = 4.24 (0.99-18.21), P = 0.052]. AAA IgA-positivity was significantly associated with higher frequency of anti-microbial antibodies (P < 0.001 for EndoCab IgA and P = 0.012 for anti-OMP Plus IgA) and higher level of the enterocyte damage marker (median I-FABPAAA IgA posvsneg: 365 vs 166 pg/mL, P = 0.011), but not with serum LBP level. CONCLUSIONPresence of IgA type AAA identified PSC patients with progressive disease. Moreover, it is associated with enhanced mucosal immune response to various microbial antigens and enterocyte damage further highlighting the importance of the gut-liver interaction in PSC.

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis(PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of Ig G4-related diseases. Smallduct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor-α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.