Tunneled biopsy is an underutilised, simple, safe and efficient method for tissue acquisition from subepithelial tumours.

BACKGROUND: Tissue acquisition from subepithelial lesions is often attempted by endoscopic ultrasound (EUS)-sampling as conventional endoscopic biopsy usually fails to reach deeper layers of the gastrointestinal wall. AIM: To investigate the utilisation, safety and diagnostic yield of an intensified "bite-on-bite" tunnel biopsy technique. METHODS: In this retrospective cohort study, all patients presenting with subepithelial masses in the upper gastrointestinal tract from March 2013 to July 2019 were included. Data were analysed for size and location of the subepithelial mass, use of intensified tunnel biopsy protocol (more than 10 double bite-on-bite biopsies) or superficial conventional biopsies, histology and imaging results, occurrence of readmission and adverse events after endoscopy. RESULTS: Two hundred and twenty-nine patients with subepithelial lesions were included. Superficial conventional biopsies were taken in 117 patients and were diagnostic only in one lipoma (0.9 %). Tunnel biopsies taken in 112/229 (48.9%) patients were significantly more likely to provide histological diagnosis (53.6%; P < 0.001). For lesions ≥ 10mm the diagnostic yield of tunnel biopsies further increased to 41/67 (61.2%). No immediate or delayed complications were reported. Only 8 of the 51 endoscopists (15.7%) regularly attempted tunnel biopsies. CONCLUSION: Tunnel biopsy is a simple, safe and efficient but underutilised diagnostic modality for tissue acquisition in subepithelial masses. It should be routinely attempted at the initial endoscopy.

Pancreatic anti-GP2 and anti-Saccharomyces cerevisiae antibodies in ruminants with paratuberculosis: A better understanding of the immunopathogenesis of Crohn's disease.

INTRODUCTION: Ruminants (cattle and sheep) with Mycobacterium avium (MAP)-induced paratuberculosis (ptb), the ruminant model of Crohn's disease (CD), exhibit pancreatic specific autoantibodies (PAB) against GP2 but not against CUZD1. Since anti-Saccharomyces cerevisiae antibodies (ASCAs) is a CD marker, we tested MAP-infected ptb ruminants for ASCA, and compared them with ruminants lacking evidence of anti-MAP serology or with ruminants, which were positive for anti-GP2 antibodies. MATERIAL AND METHODS: A total of 98 samples from ruminants (48 cattle and 50 sheep) were studied. IgG anti-MAP antibodies, and CD-related ASCA and anti-GP2 antibodies were tested by modified ELISAs. RESULTS: Nine cattle (18.75%) and 20 sheep (40%) were suffered from ptb. ASCA antibodies were present in 21/48 (43.7%) cattle and 10/50 (20%) sheep while anti-GP2 antibodies were present in 14/48 (29.2%) cattle, and 8/50 (16%) sheep. ASCA antibodies were more prevalent in anti-MAP antibody positive (14/29, 48.3%) than in anti-MAP negative ruminants (17/69, 24.6%, P=0.022) and also in anti-GP2 antibody positive (13/23, 56.5%) than in anti-GP2 negative ruminants (18/75, 24%, P=0.003). No association between ASCA and anti-MAP antibody concentrations were found (r=0.159, P=0.117). A significant association between ASCA and anti-GP2 antibody concentration were observed (r=0.211 and P=0.037). CONCLUSION: ASCA are present in a significant proportion of ruminants with ptb and correlate with anti-GP2 antibody positivity, a finding further supporting the notion that Crohn's disease and ptb share common immunological mechanisms of antigen-driven loss of self-tolerance.

Endoscopic ultrasound-guided drainage of pancreatic walled-off necrosis using self-expanding metal stents without fluoroscopy.

AIM: To investigate whether endoscopic ultrasound (EUS)-guided insertion of fully covered self-expandable metal stents in walled-off pancreatic necrosis (WOPN) is feasible without fluoroscopy. METHODS: Patients with symptomatic pancreatic WOPN undergoing EUS-guided transmural drainage using self-expandable and fully covered self expanding metal stents (FCSEMS) were included. The EUS visibility of each step involved in the transmural stent insertion was assessed by the operators as "visible" or "not visible": (1) Access to the cyst by needle or cystotome; (2) insertion of a guide wire; (3) introducing of the diathermy and delivery system; (4) opening of the distal flange; and (5) slow withdrawal of the delivery system until contact of distal flange to cavity wall. Technical success was defined as correct positioning of the FCSEMS without the need of fluoroscopy. RESULTS: In total, 27 consecutive patients with symptomatic WOPN referred for EUS-guided drainage were included. In 2 patients large traversing arteries within the cavity were detected by color Doppler, therefore the insertion of FCSEMS was not attempted. In all other patients (92.6%) EUS-guided transgastric stent insertion was technically successful without fluoroscopy. All steps of the procedure could be clearly visualized by EUS. Nine patients required endoscopic necrosectomy through the FCSEMS. Adverse events were two readmissions with fever and one self-limiting bleeding; there was no procedure-related mortality. CONCLUSION: The good endosonographic visibility of the FCSEMS delivery system throughout the procedure allows safe EUS-guided insertion without fluoroscopy making it available as bedside intervention for critically ill patients.

Placebo response and remission rates in randomised trials of induction and maintenance therapy for ulcerative colitis.

BACKGROUND: It is important to minimize placebo rates in randomised controlled trials (RCTs) to efficiently detect treatment differences between interventions. Historically, high placebo rates have been observed in clinical trials of ulcerative colitis (UC). A better understanding of factors influencing placebo rates may lead to more informed clinical trial design. OBJECTIVES: A systematic review and meta-analysis was conducted to evaluate placebo response and remission rates in RCTs evaluating UC treatments in adult patients. SEARCH METHODS: Electronic databases (i.e. MEDLINE, EMBASE, and CENTRAL) were searched from inception to 1 March 2017 with no language restrictions applied. Reference lists and conference proceedings of major gastroenterology meetings were also handsearched to identify additional studies. SELECTION CRITERIA: Placebo-controlled RCTs of adult patients with UC treated with corticosteroids, aminosalicylates, immunosuppressives or biologics were eligible, provided enrolment and outcome assessment was conducted using the Ulcerative Colitis Disease Activity Index (UCDAI) or the Mayo Clinic Score. The minimum trial duration was two weeks for induction trials and four months maintenance trials. DATA COLLECTION AND ANALYSIS: Pairs of authors independently determined study eligibility and extracted data with any disagreements resolved through consensus. Outcomes of interest included the proportion of patients with clinical response and remission. Trial characteristics such as the design, participant demographics and disease history, interventions, and enrolment and assessment criteria were also recorded. The methodological quality of the included studies was evaluated using the Cochrane risk of bias tool. Pooled placebo response and remission rates and 95% confidence intervals (95% CI) were calculated using a binomial normal model for proportions. Induction of remission and maintenance studies were pooled separately. The impact of study-level characteristics on placebo response and remission rates was investigated using mixed-effects meta-regression analyses with logits of event rates as the outcome variables. An assessment of pooled placebo rates over time was conducted using a cumulative meta-analysis based on date of publication. Publication bias was examined using funnel plots. MAIN RESULTS: The screening process identified 61 included studies which encompass 58 induction phases (5111 patients randomised to placebo) and 12 maintenance phases (1579 patients randomised to placebo). For induction trials, the pooled estimate of placebo response was 33% (95% CI 30% to 36%) while the pooled estimate of placebo remission was 12% (95% CI 9% to 15%). For maintenance trials, the pooled estimate of placebo response was 23% (95% CI 19% to 28%) while the pooled estimate of placebo remission was 17% (95% CI 10% to 27%).Studies enrolling patients with more active disease confirmed objectively by endoscopy were associated with significantly lower placebo remission and response rates than trials enrolling patients with less active disease (27% versus 4%, OR 2.60, 95% CI 1.25 to 5.42, P = 0.01 for UCDAI endoscopy sub score ≥1 versus ≥ 2 for remission; and 27% versus 4%, OR 1.70, 95% CI 1.02 to 2.82, P = 0.02 for UCDAI endoscopy sub score greater than or equal to one versus greater than or equal to two for response). With respect to drug class, the lowest placebo response and remission rates were observed in trials evaluating corticosteroids (23%; 95% CI 19 to 29%, and 5%; 95% CI 2 to 11%, respectively). Trials of biologics had the highest placebo response rate (35%; 95% CI 30 to 41%), while trials evaluating aminosalicylates had the highest placebo remission rate (18%; 95% CI 12 to 24%). Disease duration of greater than five years prior to enrolment was associated with a significantly lower placebo response rate compared to disease duration of less than or equal to five years (29% versus 47%, respectively; OR 0.54, 95% CI 0.32 to 0.92, P = 0.02). The requirement of a minimum rectal bleeding score for study eligibility was associated with an increased placebo response rate compared to studies that did not use rectal bleeding for trial eligibility (37% versus 32%, respectively; OR 1.70, 95% CI 1.02 to 2.82, P = 0.02). Finally, the time point of primary outcome assessment was found to be significantly associated with placebo remission rates such that every one week increment in endpoint assessment was associated with a 6% increase in the placebo remission rate (OR 1.06, 95% CI 1.02 to 1.10, P = 0.01).Cumulative meta-analysis indicated a consistent increase in the placebo response rate from 1987 to 2007 (from 13% to 33%), although rates have remained constant from 2008 to 2015 (32% to 34%). Similarly, placebo remission rates increased from 1987 to 2007 (5% to 14%) but have remained constant from 2008 to 2015 (12 to 14%). On meta-regression, there were no statistically significant differences between the 1987-2007 and 2008-2015 point estimates for both response (P = 0.81) and remission (P = 0.32). AUTHORS' CONCLUSIONS: Placebo response and remission rates vary according to endoscopic disease severity and rectal bleeding score at trial entry, class of agent, disease duration, and the time point at which the primary outcome was measured. These observations have important implications for the design and conduct of future clinical trials in UC and will help researchers design trials, determine required sample sizes and also provide useful information about trial design features which should be considered when planning new trials.

Non-radical, stepwise complete endoscopic resection of Barrett's epithelium in short segment Barrett's esophagus has a low stricture rate.

Background and aims: Radical endoscopic excision of Barrett's epithelium performing 4 - 6 endoscopic resections during the same endoscopic session results in complete Barrett's eradication but has a high stricture rate (40 - 80 %). Therefore radiofrequency ablation is preferred after endoscopic mucosal resection (EMR) of visible nodules. We investigated the clinical outcome of non-radical, stepwise endoscopic mucosal resection with a maximum of two endoscopic resections per endoscopic session. Methods: We analysed our prospectively maintained database of patients undergoing esophageal EMR for early neoplasia in Barrett's esophagus from 2009 to 2014. EMR was performed using a maximum of two band ligation mucosectomies per endoscopic session; thereafter, follow-up was 3-monthly and EMR was repeated as required for Barrett's eradication. Results: In total, 118 patients underwent staging EMR for early Barrett's neoplasia. Subsequently, 27 patients underwent surgery/chemotherapy due to deep submucosal or more advanced tumor stages or were managed conservatively. The remaining 91 patients with high grade dysplasia (48), intramucosal (38) or submucosal cancer (5) in the resected nodule underwent further endoscopic therapy with a mean follow-up of 24 months. Remission of dysplasia/neoplasia was achieved in 95.6 % after 12 months treatment. Stepwise endoscopic Barrett's resection resulted in complete Barrett's eradication in 36/91 patients (39.6 %) in a mean of four sessions; 40/91 patients (44.0 %) had a short circumferential Barrett's segment (< 3 cm). In this group, repeated EMR achieved complete Barrett's excision in 85.0 %. One patient developed a stricture (1.1 %), one a delayed bleeding, and there were no perforations. Conclusion: In patients with a short Barrett's segment, non-radical endoscopic Barrett's resection at the time of scheduled endoscopy follow-up allows complete Barrett's eradication with very low stricture rate.

Systematic Review and Meta-analysis: Placebo Rates in Induction and Maintenance Trials of Ulcerative Colitis.

BACKGROUND AND AIMS: Minimisation of the placebo responses in randomised controlled trials [RCTs] is essential for efficient evaluation of new interventions. Placebo rates have been high in ulcerative colitis [UC] clinical trials, and factors influencing this are poorly understood. We quantify placebo response and remission rates in UC RCTs and identify trial design factors influencing them. METHODS: MEDLINE, EMBASE, and the Cochrane Library were searched from inception through April 2014 for placebo-controlled trials in adult patients with UC of a biological agent, corticosteroid, immunosuppressant, or aminosalicylate. Data were independently doubly extracted. Quality was assessed using the Cochrane risk of bias tool. RESULTS: In all, 51 trials [48 induction and 10 maintenance phases] were identified. Placebo response and remission rates were pooled according to random-effects models, and mixed-effects meta-regression models were used to evaluate effects of study-level characteristics on these rates. Pooled estimates of placebo remission and response rates for induction trials were 10% (95% confidence interval [CI] 7-13%) and 33% [95% CI 29-37%], respectively. Corresponding values for maintenance trials were 19% [95% CI 11-30%] and 22% [95% CI 17-28%]. Trials enrolling patients with more active disease confirmed by endoscopy [endoscopy subscore ≥ 2] were associated with lower placebo rates. Conversely, placebo rates increased with increasing trial duration and number of study visits. CONCLUSIONS: Objective assessment of greater disease activity at trial entry by endoscopy lowered placebo rates, whereas increasing trial duration and more interactions with healthcare providers increased placebo rates. These findings have important implications for design and conduct of clinical trials.

Diagnostic and clinical significance of Crohn's disease-specific pancreatic anti-GP2 and anti-CUZD1 antibodies.

BACKGROUND: Pancreatic autoantibodies (PAB) targeting GP2 and CUZD1 are Crohn's disease (CrD)-markers. The clinical significance of anti-GP2 antibodies has been assessed, but that of anti-CUZD1 remains elusive. The aim of the study was to assess the clinical utility of anti-CUZD1/anti-GP2 by novel cell-based indirect immunofluorescence (IIF) assays in CrD. METHODS: A total of 212 CrD and 249 UC patients followed up at a London IBD centre were investigated to simultaneously detect PABs, anti-GP2 and anti-CUZD1 by IIF using primate pancreatic tissue, and HEK293 over-expressing CUZD1 or GP2. RESULTS: Overall, 88 (41.5%) CrDs compared to 26 (10.4%) UCs (p<0.001) tested positive for IgA and/or IgG anti-GP2 and/or anti-CUZD1 antibodies, while ASCA were found in 67.5% CrDs versus 19.2% UCs (p<0.0001); ASCA and/or PAB (anti-GP2 or anti-CUZD1) were detected in 76% CrD versus 34% UC patients. IgG anti-GP2 antibodies were less prevalent in L2 phenotype (p=0.002) and more prevalent in patients with stricturing disease (p=0.0418), even when a higher cut-off (≥1000 RU) was used (p=0.0396). Also, anti-GP2 IgG positive CrD patients had younger age of disease onset. IgA and/or IgG ASCA and anti-GP2 IgG antibody positive CrDs had younger onset of disease (p<0.0001), were more likely to have both ileal and colonic disease (p<0.0001) and had more stricturing (p<0.0001) than seronegative patients. Clinical correlates were not found for anti-CUZD1 positivity. CONCLUSIONS: PAB testing increases ASCA's serological sensitivity for CrD. Anti-GP2 detection, in isolation or in combination with ASCA, stratify CrD patients who phenotypically are characterised by a much younger onset of disease, extensive and stricturing behaviour.

Endoscopic mucosal resection of early oesophageal neoplasia in patients requiring anticoagulation: is it safe?

BACKGROUND AND AIM: Endoscopic mucosal resection (EMR) has become the standard treatment for early oesophageal neoplasia. The mucosal defect caused by EMR usually takes several weeks to heal. Despite guidelines on high-risk endoscopic procedures in patients on anticoagulation, evidence is lacking whether EMR is safe in such patients. We investigated the immediate and delayed bleeding risk in patients undergoing diagnostic or therapeutic oesophageal EMR comparing patients requiring warfarin anticoagulation with a control group. METHODS: Warfarin was stopped 5 days before the planned EMR and restarted on the evening following the procedure. Patients with high-risk conditions, such as recent pulmonary thromboemboli, received bridging with low molecular weight heparin. All EMRs were performed when the INR was <1.5. Bleeding events on the day of the EMR and within 3 months post-procedure were documented. RESULTS: One hundred and seventeen consecutive patients with early oesophageal neoplasia were included. Sixty-eight EMRs were performed in 15 patients requiring anticoagulation. One patient on warfarin was readmitted 10 days after EMR with haematemesis and melaena. Out of 400 EMRs in 102 controls, 26 immediate bleeding events occurred requiring endoscopic intervention. One delayed bleeding event (melaena) occurred in the control group. The number of bleeding events did not differ between groups [p = 0.99; odds ratio 1.01 (0.30-3.44)], neither for acute (p = 0.76) nor delayed bleeding (p = 0.24). CONCLUSION: EMR of early oesophageal neoplasia can be safely performed in patients requiring anticoagulation when warfarin is discontinued 5 days before the endoscopic intervention and reinstituted on the evening of the procedure day.

Dietary intake of inulin-type fructans in active and inactive Crohn's disease and healthy controls: a case-control study.

BACKGROUND AND AIMS: Prebiotic inulin-type fructans are widely consumed in the diet and may have contrasting effects in Crohn's disease by stimulating gut microbiota and/or by generating functional gastrointestinal symptoms. The aim of this study was to measure fructan and oligofructose intakes in patients with active and inactive Crohn's disease compared with healthy controls. METHODS: Patients with active Crohn's disease (n = 98), inactive Crohn's (n = 99) and healthy controls (n = 106) were recruited to a case-control study. Dietary intake of inulin-type fructans was measured using a specific food frequency questionnaire and was compared between the three groups and between patients with different disease phenotypes (Montreal classification). Associations between intakes and disease activity (Harvey-Bradshaw Index, HBI) were also undertaken. RESULTS: Patients with active Crohn's disease had lower fructan intakes (median 2.9 g/d, interquartile range [IQR] 1.8) than those with inactive Crohn's (3.6 g/d, 2.1, p = 0.036) or controls (3.9 g/d, 2.1, p = 0.003) and lower oligofructose intakes (2.8 g/d, 1.8) than those with inactive Crohn's (3.5 g/d, 2.2, p = 0.048) or controls (3.8 g/d, 2.1, p = 0.003). There were no differences in intakes related to disease site or behaviour. There were negative correlations between HBI well-being score and fructan intake (ρ = -0.154, p = 0.03) and oligofructose intake (ρ = -0.156, p = 0.028) and for the HBI abdominal pain score and fructan (ρ = -0.164, p = 0.021) and oligofructose intake (ρ = -0.157, p = 0.027). CONCLUSIONS: Patients with active Crohn's disease consume lower quantities of fructans and oligofructose than their inactive counterparts and healthy controls. The impact of lower intakes of prebiotic fructans on gut microbiota is unknown and warrants further research.

Diagnostic and clinical significance of Crohn's disease-specific anti-MZGP2 pancreatic antibodies by a novel ELISA.

BACKGROUND: We developed a new IgA and IgG anti-MZGP2 antibody ELISAs based on recombinant isoform-4 of human zymogen granule protein-2 (GP2), which is the major autoantigen of Crohn's disease (CrD)-specific pancreatic autoantibodies and assessed their clinical relevance in the largest inflammatory bowel disease (IBD) cohort tested to date. METHODS: 832 sera were studied, including 617 consecutive IBD patients from 323 CrD and 294 ulcerative colitis (UC) follow-up in a tertiary centre, and 112 pathological and 103 normal controls. RESULTS: Sensitivity of IgA anti-MZGP2 for CrD in the IBD population was 15% and specificity was 98% (95, 99), while the sensitivity and specificity of IgG anti-MZGP2 were 27% and 97%. IgA and IgG anti-MZGP2 combined testing led to a sensitivity of 31% and a specificity of 96%. Positivity for either ASCA (IgA or IgG) or anti-MZGP2 (IgA or IgG) showed a sensitivity of 75% (70, 80) and a specificity of 84% (79, 89). IgA anti-MZGP2 antibodies were more prevalent in CrD patients with early disease onset (p=0.011). Also, anti-MZGP2 positive patients more frequently had extensive disease with ileal involvement. Patients with longer disease duration were more likely to have IgG anti-MZGP2 antibodies. CONCLUSIONS: Our novel ELISA confirms the high specificity of anti-MZGP2 antibodies for CrD and their association with disease severity phenotypes.

Bioinformatic and immunological analysis reveals lack of support for measles virus related mimicry in Crohn's disease.

BACKGROUND: A link between measles virus and Crohn's disease (CD) has been postulated. We assessed through bioinformatic and immunological approaches whether measles is implicated in CD induction, through molecular mimicry. METHODS: The BLAST2p program was used to identify amino acid sequence similarities between five measles virus and 56 intestinal proteins. Antibody responses to measles/human mimics were tested by an in-house ELISA using serum samples from 50 patients with CD, 50 with ulcerative colitis (UC), and 38 matched healthy controls (HCs). RESULTS: We identified 15 sets of significant (>70%) local amino acid homologies from two measles antigens, hemagglutinin-neuraminidase and fusion-glycoprotein, and ten human intestinal proteins. Reactivity to at least one measles 15-meric mimicking peptide was present in 27 out of 50 (54%) of patients with CD, 24 out of 50 (48%) with UC (CD versus UC, p = 0.68), and 13 out of 38 (34.2%) HCs (CD versus HC, p = 0.08). Double reactivity to at least one measles/human pair was present in four out of 50 (8%) patients with CD, three out of 50 (6%) with UC (p = 0.99), and in three out of 38 (7.9%) HCs (p >0.05 for all). Titration experiments yielded different extinction curves for anti-measles and anti-human intestinal double-reactive antibodies. Epitope prediction algorithms and three-dimensional modeling provided bioinformatic confirmation for the observed antigenicity of the main measles virus epitopic regions. CONCLUSIONS: Measles sequences mimicking intestinal proteins are frequent targets of antibody responses in patients with CD, but this reactivity lacks disease specificity and does not initiate cross-reactive responses to intestinal mimics. We conclude that there is no involvement of measles/human molecular mimicry in the etiopathogenesis of CD.

Indolent systemic mastocytosis in a patient with ileocolitis.

Systemic mastocytosis is a clonal disorder of the mast cell and its progenitor cell. It is a rare disorder with unknown incidence in Greece, with an estimate of 2 cases per year in Great Britain. We present a case of an asymptomatic, 72-year-old man who was found to have ileocolitis on endoscopy. Histology revealed mast cells in lamina propria >15 HPF and biochemistry showed high levels of serum total tryptase. Molecular testing was positive for the mutation Asp816Val in exon 17 of c-kit gene. The patient met one major and two minor criteria for the diagnosis of systemic indolent mastocytosis (according to WHO classification). He has been treated prophylactically with H1- and H2-histamine receptor antagonists and remains asymptomatic.

Helicobacter pylori and autoimmune disease: cause or bystander.

Helicobacter pylori (H. pylori) is the main cause of chronic gastritis and a major risk factor for gastric cancer. This pathogen has also been considered a potential trigger of gastric autoimmunity, and in particular of autoimmune gastritis. However, a considerable number of reports have attempted to link H. pylori infection with the development of extra-gastrointestinal autoimmune disorders, affecting organs not immediately relevant to the stomach. This review discusses the current evidence in support or against the role of H. pylori as a potential trigger of autoimmune rheumatic and skin diseases, as well as organ specific autoimmune diseases. We discuss epidemiological, serological, immunological and experimental evidence associating this pathogen with autoimmune diseases. Although over one hundred autoimmune diseases have been investigated in relation to H. pylori, we discuss a select number of papers with a larger literature base, and include Sjögrens syndrome, rheumatoid arthritis, systemic lupus erythematosus, vasculitides, autoimmune skin conditions, idiopathic thrombocytopenic purpura, autoimmune thyroid disease, multiple sclerosis, neuromyelitis optica and autoimmune liver diseases. Specific mention is given to those studies reporting an association of anti-H. pylori antibodies with the presence of autoimmune disease-specific clinical parameters, as well as those failing to find such associations. We also provide helpful hints for future research.

E. coli Induced Experimental Model of Primary Biliary Cirrhosis: At Last.

Recurrent urinary tract infections (UTI) have been considered potential triggers of primary biliary cirrhosis (PBC), an autoimmune cholestatic liver disease characterised by progressive destruction of intrahepatic bile ducts. Additional support for the link made between PBC and UTI was based on early observations of recurrent episodes of bacteriuria in female patients with PBC. A series of large epidemiological studies demonstrated a strong correlation between recurrent UTI and PBC, initiating a series of studies investigating the role of Escherichia coli (E. coli, the most prevalent organism isolated in women with UTI) as a trigger of PBC. Immunological evidence of B- and T-cell cross-reactive responses implicating PBC-specific autoantigens and E. coli mimics have been clearly demonstrated, adding support to the notion that E. coli is a potential infectious inducer of PBC in susceptible individuals. One of the major limitations in proving the E. coli/PBC association was the lack of reliable E. coli-infected animal models of PBC. This review provides an overview of the evidence linking this infectious agent with PBC and discusses the pros and cons of a recently developed E. coli-infected animal model of PBC.

Ileal inflammation may trigger the development of GP2-specific pancreatic autoantibodies in patients with Crohn's disease.

Why zymogen glycoprotein 2 (GP2), the Crohn's disease (CD)-specific pancreatic autoantigen, is the major target of humoral autoimmunity in inflammatory bowel diseases (IBD) is uknown. Recent evidence demonstrates that GP2 is also present on the apical surface of microfold (M) intestinal cells. As the colon lacks GP2-rich M cells, we assumed that patients with colonic CD are seronegative for anti-GP2. Anti-GP2 antibodies were tested in 225 CDs, including 45 patients with colonic location (L2), 45 with terminal ileum (L1) and 135 with ileocolonic involvement; 225 patients with ulcerative colitis (UC) were also tested. Anti-GP2 reactivity was detected in 59 (26.2%) CDs and 15 (6.7%) UCs (P < 0.001). Only 5 CDs with L2 had anti-GP2 antibodies, compared to 54/180 (30.0%, P = 0.0128) of the CDs with L1 and L3. Anti-GP2 antibody positive CD patients had higher ASCA titres compared to seronegative cases. Amongst the 128 CD patients with previous surgical intervention, 45 (35.0%) were anti-GP2 antibody positive compared to 14/97 (14.0%) without surgical (P < 0.001). Our data support the assumption that ileal inflammation is required for the development of anti-GP2 antibodies in CD, and suggest that the intestine rather than the pancreatic juice is the antigenic source required for the initiation of anti-GP2 antibodies.

Autoantibodies in autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) was first used to describe cases of pancreatitis with narrowing of the pancreatic duct, enlargement of the pancreas, hyper-γ-globulinaemia, and antinuclear antibody (ANA) positivity serologically. The main differential diagnosis, is pancreatic cancer, which can be ruled out through radiological, serological, and histological investigations. The targets of ANA in patients with autoimmune pancreatitis do not appear to be similar to those found in other rheumatological diseases, as dsDNA, SS-A, and SS-B are not frequently recognized by AIP-related ANA. Other disease-specific autoantibodies, such as, antimitochondrial, antineutrophil cytoplasmic antibodies or diabetes-specific autoantibodies are virtually absent. Further studies have focused on the identification of pancreas-specific autoantigens and reported significant reactivity to lactoferrin, carbonic anhydrase, pancreas secretory trypsin inhibitor, amylase-alpha, heat-shock protein, and plasminogen-binding protein. This paper discusses the findings of these investigations and their relevance to the diagnosis, management, and pathogenesis of autoimmune pancreatitis.

Diagnostic and clinical utility of antibodies against the nuclear body promyelocytic leukaemia and Sp100 antigens in patients with primary biliary cirrhosis.

BACKGROUND: The lack of an immunoassay that detects antibodies to promyelocytic leukaemia (PML) protein, the primary biliary cirrhosis (PBC)-specific multiple nuclear dot (MND) antigen, has prompted us to develop a line immunoassay (LIA) for the simultaneous detection of PML and Sp100 MND-specific autoantibodies. METHODS: PML and Sp100 were expressed in Escherichia coli, and analysed by SDS-PAGE and immunoblotting using a monoclonal antibody and MALDI-ToF fingerprinting. A quantitative PML and Sp100 LIA were developed and testing was performed in 150 anti-mitochondrial antibody (AMA) positive, 20 AMA-PBCs and 130 controls. RESULTS: Thirty-five (23%) of 150 AMA+ PBCs (18 anti-MND+) were anti-PML+ (12%) or anti-Sp100+ (20%), 10 being anti-PML+/Sp100+, 5 single anti-PML+ and 20 single anti-Sp100+. Six (30%, 5 anti-MND+) AMA-PBCs were anti-PML+ or Sp100+. Only 2 (1.7%) pathological controls were anti-PML+ and/or anti-Sp100+. Levels of anti-PML correlated with those of anti-Sp100 (R=0.64, p<0.0001). The autoantibody profile largely remained unchanged over a 10year-follow up (52 patients, 352 samples). Anti-PML, Sp100 or MND-reactive PBCs were younger and had longer disease duration than the seronegative (p=0.06, for both). Anti-Sp100 levels correlated with the Mayo risk score (r=0.63, p=0.01). Anti-PML+/Sp100+ patients had more advanced disease compared to patients negative for anti-PML/Sp100 (p=0.04). CONCLUSION: The new line immunoassay offers a robust and accurate method for the detection of clinically-relevant PBC-specific anti-MND antibodies.

Popular and unpopular infectious agents linked to primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease characterized by the autoimmune destruction of the biliary epithelial cells of the small and medium-size bile ducts. The disease affects middle aged women and usually affects more than one member within a family. The pathognomonic serological hallmark of the disease is the presence of circulating anti-mitochondrial antibodies, and disease-specific anti-nuclear antibodies. Susceptibility genes and environmental risk factors such as infections and smoking have been reported as important for the development of the disease. Among the environmental agents, infectious triggers are the best studied. Most of the work published so far has investigated the role of infections caused by Novosphingobium aromaticivorans and Escherichia coli. This review will discuss the popular and unpopular infectious agents causatively linked to PBC. It will also examine reports investigating the epidemiological aspects of the disease and their direct or indirect implications to bacterial-induced PBC.

Smokers with active Crohn's disease have a clinically relevant dysbiosis of the gastrointestinal microbiota.

BACKGROUND: Patients with Crohn's disease (CD) have an intestinal dysbiosis with components of the microbiota exerting differential immune effects. Smoking is associated with an increased incidence of CD, more frequent relapse, and greater burden of surgery. This study aimed to investigate the association between smoking and the intestinal microbiota in patients with active CD. METHODS: Patients with active CD (n = 103) and healthy controls (n = 66) were recruited and demographic and clinical data recorded including current smoking behavior. Fecal samples were collected and analyzed by fluorescent in situ hybridization using probes targeting 16S rRNA of bacteria previously shown to be altered in active CD (bifidobacteria, bacteroides, Clostridium coccoides-Eubacterium rectale, Escherichia coli, and Faecalibacterium prausnitzii). RESULTS: In total, 29/101 (29%) patients with CD and 8/58 (14%) controls were current smokers (P = 0.032). Following multivariate analysis, smoking was found to have a significant and independent effect on the microbiota of patients with CD, with higher Bacteroides-Prevotella in smokers (38.4%) compared with nonsmokers (28.1%) (F((1,93)) = 12.6, P = 0.001). Healthy controls who smoked also had higher Bacteroides-Prevotella (34.8%) than nonsmokers (24.1%) (F((1,55)) = 4.5, P = 0.038). In the pooled multivariate analysis, patients with CD had higher bifidobacteria (F((1,156)) = 30.5, P < 0.001), higher Bacteroides-Prevotella (F((1,156)) = 6.5, P = 0.012), and lower F. prausnitzii (F((1,156)) = 3.8, P = 0.052) compared with healthy controls. CONCLUSIONS: Smokers have luminal microbiota that consist of significantly higher bacteroides. Investigation of whether this is one mechanism through which the negative effects of smoking on CD are mediated is warranted.