Autoantibody-Mediated Depletion of IL-1RA in Still's Disease and Potential Impact of IL-1 Targeting Therapies.

BACKGROUND: Adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) resemble a continuum of a rare, polygenic IL-1ß-driven disease of unknown etiology. OBJECTIVE: In the present study we sought to investigate a potential role of recently described autoantibodies neutralizing the interleukin-1(IL-1)-receptor antagonist (IL-1-Ra) in the pathogenesis of Still's disease. METHODS: Serum or plasma samples from Still's disease patients (AOSD, n = 23; sJIA, n = 40) and autoimmune and/or inflammatory disease controls (n = 478) were analyzed for autoantibodies against progranulin (PGRN), IL-1Ra, IL-18 binding protein (IL-18BP), and IL-36Ra, as well as circulating IL-1Ra and IL-36Ra levels by ELISA. Biochemical analyses of plasma IL-1Ra were performed by native Western blots and isoelectric focusing. Functional activity of the autoantibodies was examined by an in vitro IL-1ß-signaling reporter assay. RESULTS: Anti-IL-1-Ra IgG were identified in 7 (27%) out of 29 Still's disease patients, including 4/23 with AOSD and 3/6 with sJIA and coincided with a hyperphosphorylated isoform of endogenous IL-1Ra. Anti-IL-36Ra antibodies were found in 2 AOSD patients. No anti-PGRN or anti-IL-18BP antibodies were detected. Selective testing for anti-IL-1Ra antibodies in an independent cohort (sJIA, n = 34) identified 5 of 34 (14.7%) as seropositive. Collectively, 8/12 antibody-positive Still's disease patients were either new-onset active disease or unresponsive to IL-1 blocking drugs. Autoantibody-seropositivity associated with decreased IL-1Ra plasma/serum levels. Seropositive plasma impaired in vitro IL-1Ra bioactivity, which could be reversed by anakinra or canakinumab treatment. CONCLUSION: Autoantibodies neutralizing IL-1Ra may represent a novel patho-mechanism in a subgroup of Still's disease patients, which is sensitive to high-dose IL-1 blocking therapy.

Artificial-intelligence-based decision support tools for the differential diagnosis of colitis.

BACKGROUND: Whereas Artificial Intelligence (AI) based tools have recently been introduced in the field of gastroenterology, application in inflammatory bowel disease (IBD) is in its infancies. We established AI-based algorithms to distinguish IBD from infectious and ischemic colitis using endoscopic images and clinical data. METHODS: First, we trained and tested a Convolutional Neural Network (CNN) using 1796 real-world images from 494 patients, presenting with three diseases (IBD [n = 212], ischemic colitis [n = 157], and infectious colitis [n = 125]). Moreover, we evaluated a Gradient Boosted Decision Trees (GBDT) algorithm using five clinical parameters as well as a hybrid approach (CNN + GBDT). Patients and images were randomly split into two completely independent datasets. The proposed approaches were benchmarked against each other and three expert endoscopists on the test set. RESULTS: For the image-based CNN, the GBDT algorithm and the hybrid approach global accuracies were .709, .792, and .766, respectively. Positive predictive values were .602, .702, and .657. Global areas under the receiver operating characteristics (ROC) and precision recall (PR) curves were .727/.585, .888/.823, and .838/.733, respectively. Global accuracy did not differ between CNN and endoscopists (.721), but the clinical parameter-based GBDT algorithm outperformed CNN and expert image classification. CONCLUSIONS: Decision support systems exclusively based on endoscopic image analysis for the differential diagnosis of colitis, representing a complex clinical challenge, seem not yet to be ready for primetime and more diverse image datasets may be necessary to improve performance in future development. The clinical value of the proposed clinical parameters algorithm should be evaluated in prospective cohorts.

Visualising and quantifying intestinal permeability -where do we stand.

Intestinal permeability is getting more and more attention in gastrointestinal research. Although well recognized, its exact role in health and disease is yet to be defined. There are many methods of quantifying intestinal permeability, but most of them fail to deliver tangible information about the morphological integrity of the intestinal barrier. In this review we aim to describe imaging options for the assessment of intestinal barrier integrity and their potential relevance for clinical practice. Our focus is on confocal laser endomicroscopy, which is at this time the only method for visualizing not only functional but also morphological aspects of the gut barrier in vivo.

Development and validation of a risk prediction score for severe acute pancreatitis.

INTRODUCTION: The available prognostic scoring systems for severe acute pancreatitis (SAP) have limitations that restrict their clinical value. The aim of this study was to develop a simple model (score) that could rapidly identify those at risk for SAP. METHODS: We derived a risk model using a retrospective cohort of 700 patients by logistic regression and bootstrapping methods. The discriminative power of the risk model was assessed by calculating the area under the receiver operating characteristic curves (AUC). The classification and regression tree (CART) analysis was used to create risk categories. The model was internally validated by a tenfold cross-validation and externally validated in a separate prospective cohort of 194 patients. RESULTS: The incidence of SAP was 9.7% in the derivation cohort and 9.3% in the validation cohort. A prognostic score (We denoted it as the SABP score), ranging from 0 to 10, consisting of systemic inflammatory response syndrome, serum albumin, blood urea nitrogen and pleural effusion, was developed by logistic regression and bootstrapping analysis. Patients could be divided into three risk categories according to total SABP score based on CART analysis. The mean probability of developing SAP was 1.9%, 12.8% and 41.6% in patients with low (0-3), moderate (4-6) and high (7-10) SABP score, respectively. The AUCs of prognostic score in tenfold cross-validation was 0.873 and 0.872 in the external validation. CONCLUSION: Our risk prediction score may assist physicians in predicting the development of SAP.

Patient Age, Sex, and Inflammatory Bowel Disease Phenotype Associate With Course of Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is an orphan hepatobiliary disorder associated with inflammatory bowel disease (IBD). We aimed to estimate the risk of disease progression based on distinct clinical phenotypes in a large international cohort of patients with PSC. METHODS: We performed a retrospective outcome analysis of patients diagnosed with PSC from 1980 through 2010 at 37 centers in Europe, North America, and Australia. For each patient, we collected data on sex, clinician-reported age at and date of PSC and IBD diagnoses, phenotypes of IBD and PSC, and date and indication of IBD-related surgeries. The primary and secondary endpoints were liver transplantation or death (LTD) and hepatopancreatobiliary malignancy, respectively. Cox proportional hazards models were applied to determine the effects of individual covariates on rates of clinical events, with time-to-event analysis ascertained through Kaplan-Meier estimates. RESULTS: Of the 7121 patients in the cohort, 2616 met the primary endpoint (median time to event of 14.5 years) and 721 developed hepatopancreatobiliary malignancy. The most common malignancy was cholangiocarcinoma (n = 594); patients of advanced age at diagnosis had an increased incidence compared with younger patients (incidence rate: 1.2 per 100 patient-years for patients younger than 20 years old, 6.0 per 100 patient-years for patients 21-30 years old, 9.0 per 100 patient-years for patients 31-40 years old, 14.0 per 100 patient-years for patients 41-50 years old, 15.2 per 100 patient-years for patients 51-60 years old, and 21.0 per 100 patient-years for patients older than 60 years). Of all patients with PSC studied, 65.5% were men, 89.8% had classical or large-duct disease, and 70.0% developed IBD at some point. Assessing the development of IBD as a time-dependent covariate, Crohn's disease and no IBD (both vs ulcerative colitis) were associated with a lower risk of LTD (unadjusted hazard ratio [HR], 0.62; P < .001 and HR, 0.90; P = .03, respectively) and malignancy (HR, 0.68; P = .008 and HR, 0.77; P = .004, respectively). Small-duct PSC was associated with a lower risk of LTD or malignancy compared with classic PSC (HR, 0.30 and HR, 0.15, respectively; both P < .001). Female sex was also associated with a lower risk of LTD or malignancy (HR, 0.88; P = .002 and HR, 0.68; P < .001, respectively). In multivariable analyses assessing the primary endpoint, small-duct PSC characterized a low-risk phenotype in both sexes (adjusted HR for men, 0.23; P < .001 and adjusted HR for women, 0.48; P = .003). Conversely, patients with ulcerative colitis had an increased risk of liver disease progression compared with patients with Crohn's disease (HR, 1.56; P < .001) or no IBD (HR, 1.15; P = .002). CONCLUSIONS: In an analysis of data from individual patients with PSC worldwide, we found significant variation in clinical course associated with age at diagnosis, sex, and ductal and IBD subtypes. The survival estimates provided might be used to estimate risk levels for patients with PSC and select patients for clinical trials.

A Variant of COL3A1 (rs3134646) Is Associated With Risk of Developing Diverticulosis in White Men.

BACKGROUND: Colonic diverticulosis is one of the most common gastroenterological disorders. Although diverticulosis is typically benign, many individuals develop diverticulitis or other aspects of diverticular disease. Diverticulosis is thought to stem from a complex interaction of environmental, dietary, and genetic factors; however, the contributing genetic factors remain unknown. OBJECTIVE: The aim of our present study was to determine the role of genetic variants within genes encoding for collagens of the connective tissue in diverticulosis. DESIGN: This was a transsectional genetic association study. SETTINGS: This study was conducted at three tertiary referral centers in Germany and Lithuania. PATIENTS: Single-nucleotide polymorphisms in COL3A1 (rs3134646, rs1800255) and COL1A1 (rs1800012) were genotyped in 422 patients with diverticulosis and 285 controls of white descent by using TaqMan assays. MAIN OUTCOME MEASURES: The association of colonoscopy-proven diverticulosis with genetic polymorphisms with herniations was assessed in multivariate models. RESULTS: The rs3134646, rs1800255, and rs1800012 variants were significantly associated with the risk of developing diverticulosis in the univariate model; however, these associations were not significant in the multivariate logistic regression analysis including additional nongenetic variables. When selectively analyzing sexes, the genotype AA (AA) in rs3134646 remained significantly associated with diverticulosis in men (OR, 1.82; 95% CI, 1.04-3.20; p = 0.04). LIMITATIONS: Because a candidate approach was used, additional relevant variants could be missed. Within our cohort of patients with diverticulosis, only a small proportion had diverticular disease and thus, we could not examine the variants in these subgroups. Functional studies, including the analysis of the involved collagens, are also warranted. CONCLUSIONS: Our study shows that a variant of COL3A1 (rs3134646) is associated with the risk of developing colonic diverticulosis in white men, whereas rs1800255 (COL3A1) and rs1800012 (COL1A1) were not associated with this condition after adjusting for confounding factors. Our data provide novel valuable insights in the genetic susceptibility to diverticulosis. See Video Abstract at http://links.lww.com/DCR/A504.

Selective association of nonaspirin NSAIDs with risk of diverticulitis.

PURPOSE: The purpose of this study is to investigate the association of intake of nonsteroidal anti-inflammatory drugs (NSAIDs) and in particular nonaspirin NSAIDs and compare it with other risk factors for the progression of diverticulosis to diverticulitis in patients who underwent colonoscopy. METHODS: A total of 194 patients who underwent complete colonoscopy in our center between 2012 and 2016 were recruited: 144 with diverticulosis without prior diverticulitis (median age 71 years, 59.7% men) and 50 with diverticulitis (median age 64 years, 54.0% men). Data concerning current and previous medication as well as concomitant diseases were collected using a structured questionnaire and by revision of patients medical charts. RESULTS: Patients with diverticulitis were significantly (p < 0.001) younger as compared to individuals with plain diverticulosis (median age 64 versus 71 years, respectively). The intake of NSAIDs significantly (p = 0.002) increased the risk of prior diverticulitis (OR 3.2, 95% CI 1.5-6.9). In the multivariate model, both age (p < 0.001) and NSAIDs (p = 0.03) proved to be independent determinants of diverticulitis. When analyzing aspirin intake, it was not associated with diverticulitis. CONCLUSIONS: Our study demonstrates, in line with previous reports, that intake of NSAIDs is associated with diverticulitis. We show in particular that nonaspirin NSAIDs might be selectively associated with diverticulitis. These results point to divergent role of aspirin and nonaspirin NSAIDs in the development of diverticulitis.

Delta-Like Ligand 4 Modulates Liver Damage by Down-Regulating Chemokine Expression.

Disrupting Notch signaling ameliorates experimental liver fibrosis. However, the role of individual Notch ligands in liver damage is unknown. We investigated the effects of Delta-like ligand 4 (Dll4) in liver disease. DLL4 expression was measured in 31 human liver tissues by immunohistochemistry. Dll4 function was examined in carbon tetrachloride- and bile duct ligation-challenged mouse models in vivo and evaluated in hepatic stellate cells, hepatocytes, and Kupffer cells in vitro. DLL4 was expressed in patients' Kupffer and liver sinusoidal endothelial cells. Recombinant Dll4 protein (rDll4) ameliorated hepatocyte apoptosis, inflammation, and fibrosis in mice after carbon tetrachloride challenge. In vitro, rDll4 significantly decreased lipopolysaccharide-dependent chemokine expression in both Kupffer and hepatic stellate cells. In bile duct ligation mice, rDll4 induced massive hepatic necrosis, resulting in the death of all animals within 1 week. Inflammatory cell infiltration and chemokine ligand 2 (Ccl2) expression were significantly reduced in rDll4-receiving bile duct ligation mice. Recombinant Ccl2 rescued bile duct ligation mice from rDll4-mediated death. In patients with acute-on-chronic liver failure, DLL4 expression was inversely associated with CCL2 abundance. Mechanistically, Dll4 regulated Ccl2 expression via NF-κB. Taken together, Dll4 modulates liver inflammatory response by down-regulating chemokine expression. rDll4 application results in opposing outcomes in two models of liver damage. Loss of DLL4 may be associated with CCL2-mediated cytokine storm in patients with acute-on-chronic liver failure.