Systematic review: new serological markers (anti-glycan, anti-GP2, anti-GM-CSF Ab) in the prediction of IBD patient outcomes. Autoimmun Rev. 2015;14:231-245. [PMID: 25462578 DOI: 10.1016/j.autrev.2014.11.004]

Coincidence of antibodies against Hwp1 and ASCA, two distinct molecular targets of Candida albicans, reinforces the link between this fungal species and coeliac disease

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibodies (ASCA), a serological marker of Crohn's disease. ASCA has also been reported in other autoimmune diseases, including coeliac disease (CeD). A strong antibody response against Hwp1, a protein associated with invasive hyphal form of C. albicans which presents peptide sequence homologies with gliadin, has also been described in CeD. This observation supports the hypothesis that C. albicans hyphal transition in C. albicans may trigger CeD onset through a mechanism of molecular/antigenic mimicry. In this study, we assessed whether the anti-C. albicans oligomannose and anti-Hwp1 protein responses may be linked despite their different pathophysiological significance. The measurement of ASCA levels in a cohort of patients involved in our previous Hwp1 study showed a significant correlation between the two biomarkers. This new observation further reinforces the link between C. albicans and CeD.

MiR-146a alleviates inflammatory bowel disease in mice through systematic regulation of multiple genetic networks

Introduction

Inflammatory bowel disease (IBD) is a chronic disease involving multiple genes, and the current available targeted drugs for IBD only deliver moderate efficacy. Whether there is a single gene that systematically regulates IBD is not yet known. MiR-146a plays a pivotal role in repression of innate immunity, but its function in the intestinal inflammation is sort of controversy, and the genetic regulatory networks regulated by miR-146a in IBD has not been revealed.

Methods

RT-qPCR was employed to detect the expression of miR-146a in IBD patients and in a mouse IBD model induced by dextran sulfate sodium (DSS), and then we generated a miR-146a knock-out mouse line with C57/Bl6N background. The disease activity index was scored in DSS-treated miR-146a deficiency mice and their wild type (WT) littermates. Bulk RNA-sequencing, RT-qPCR and immunostaining were done to illustrate the downstream genetic regulatory networks of miR-146a in flamed colon. Finally, the modified miR-146a mimics were used to treat DSS-induced IBD in miR-146a knock-out and WT IBD mice.

Results

We showed that the expression of miR-146a in the colon was elevated in dextran sulfate sodium (DSS)-induced IBD mice and patients with IBD. DSS induced dramatic body weight loss and more significant rectal bleeding, shorter colon length, and colitis in miR-146a knock-out mice than WT mice. The miR-146a mimics alleviated DSS-induced symptoms in both miR-146a-/- and WT mice. Further RNA sequencing illustrated that the deficiency of miR-146a de-repressed majority of DSS-induced IBD-related genes that cover multiple genetic regulatory networks in IBD, and supplementation with miR-146a mimics inhibited the expression of many IBD-related genes. Quantitative RT-PCR or immunostaining confirmed that Ccl3, Saa3, Csf3, Lcn2, Serpine1, Serpine2, MMP3, MMP8, MMP10, IL1A, IL1B, IL6, CXCL2, CXCL3, S100A8, S100A9, TRAF6, P65, p-P65, and IRAK1 were regulated by miR-146a in DSS induced IBD. Among them, MMP3, MMP10, IL6, IL1B, S100A8, S100A9, SERPINE1, CSF3, and IL1A were involved in the active stage of IBD in humans.

Discussion

Our date demonstrated that miR-146a acts as a top regulator in C57/BL6N mice to systematically repress multiple genetic regulatory networks involved in immune response of intestine to environment factors, and combinatory treatment with miR-146a-5p and miR-146a-3p mimics attenuates DSS-induced IBD in mice through down-regulating multiple genetic regulatory networks which were increased in colon tissue from IBD patients. Our findings suggests that miR-146a is a top inhibitor of IBD, and that miR-146a-5p and miR-146a-3p mimics might be potential drug for IBD.

Recent Trends in Non-Invasive Methods of Diagnosis and Evaluation of Inflammatory Bowel Disease: A Short Review

Inflammatory bowel diseases are a conglomerate of disorders causing inflammation of the gastrointestinal tract, which have gained a significant increase in prevalence in the 21st century. As they present a challenge in the terms of diagnosis as well as treatment, IBDs can present an overwhelming impact on the individual and can take a toll on healthcare costs. Thus, a quick and precise diagnosis is required in order to prevent the high number of complications that can arise from a late diagnosis as well as a misdiagnosis. Although endoscopy remains the primary method of evaluation for IBD, recent trends have highlighted various non-invasive methods of diagnosis as well as reevaluating previous ones. This review focused on the current non-invasive methods in the diagnosis of IBD, exploring their possible implementation in the near future, with the goal of achieving earlier, feasible, and cheap methods of diagnosis as well as prognosis in IBD.

From ASCA breakthrough in Crohn's disease and Candida albicans research to thirty years of investigations about their meaning in human health

Anti-Saccharomyces cerevisiae antibodies (ASCA) are human antibodies that can be detected using an enzyme-linked immunosorbent assay involving a mannose polymer (mannan) extracted from the cell wall of the yeast S. cerevisiae. The ASCA test was developed in 1993 with the aim of differentiating the serological response in two forms of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis. The test, which is based on the detection of anti-oligomannosidic antibodies, has been extensively performed worldwide and there have been hundreds of publications on ASCA. The earlier studies concerned the initial diagnostic indications of ASCA and investigations then extended to many human diseases, generally in association with studies on intestinal microorganisms and the interaction of the micro-mycobiome with the immune system. The more information accumulates, the more the mystery of the meaning of ASCA deepens. Many fundamental questions remain unanswered. These questions concern the heterogeneity of ASCA, the mechanisms of their generation and persistence, the existence of self-antigens, and the relationship between ASCA and inflammation and autoimmunity. This review aims to discuss the gray areas concerning the origin of ASCA from an analysis of the literature. Structured around glycobiology and the mannosylated antigens of S. cerevisiae and Candida albicans, this review will address these questions and will try to clarify some lines of thought. The importance of the questions relating to the pathophysiological significance of ASCA goes far beyond IBD, even though these diseases remain the preferred models for their understanding.

Bringing to Light the Risk of Colorectal Cancer in Inflammatory Bowel Disease: Mucosal Glycosylation as a Key Player

Colitis-associated cancer is a major complication of inflammatory bowel disease remaining an important clinical challenge in terms of diagnosis, screening, and prognosis. Inflammation is a driving factor both in inflammatory bowel disease and cancer, but the mechanism underlying the transition from colon inflammation to cancer remains to be defined. Dysregulation of mucosal glycosylation has been described as a key regulatory mechanism associated both with colon inflammation and colorectal cancer development. In this review, we discuss the major molecular mechanisms of colitis-associated cancer pathogenesis, highlighting the role of glycans expressed at gut epithelial cells, at lamina propria T cells, and in serum proteins in the regulation of intestinal inflammation and its progression to colon cancer, further discussing its potential clinical and therapeutic applications.

Biomarkers for the Prediction and Diagnosis of Fibrostenosing Crohn's Disease: A Systematic Review

BACKGROUND AND AIMS

Intestinal strictures are a common complication of Crohn's disease (CD). Biomarkers of intestinal strictures would assist in their prediction, diagnosis, and monitoring. Herein we provide a comprehensive systematic review of studies assessing biomarkers that may predict or diagnose CD-associated strictures.

METHODS

We performed a systematic review of PubMed, EMBASE, ISI Web of Science, Cochrane Library, and Scopus to identify citations pertaining to biomarkers of intestinal fibrosis through July 6, 2020, that used a reference standard of full-thickness histopathology or cross-sectional imaging or endoscopy. Studies were categorized based on the type of biomarker they evaluated (serum, genetic, histopathologic, or fecal).

RESULTS

Thirty-five distinct biomarkers from 3 major groups were identified: serum (20 markers), genetic (9 markers), and histopathology (6 markers). Promising markers include cartilage oligomeric matrix protein, hepatocyte growth factor activator, and lower levels of microRNA-19-3p (area under the curves were 0.805, 0.738, and 0.67, respectively), and multiple anti-flagellin antibodies (A4-Fla2 [odds ratio, 3.41], anti Fla-X [odds ratio, 2.95], and anti-CBir1 [multiple]). Substantial heterogeneity was observed and none of the markers had undergone formal validation. Specific limitations to acceptance of these markers included failure to use a standardized definition of stricturing disease, lack of specificity, and insufficient relevance to the pathogenesis of intestinal strictures or incomplete knowledge regarding their operating properties.

CONCLUSIONS

There is a lack of well-defined studies on biomarkers of intestinal stricture. Development of reliable and accurate biomarkers of stricture is a research priority. Biomarkers can support the clinical management of CD patients and aid in the stratification and monitoring of patients during clinical trials of future antifibrotic drug candidates.

Macrophage control of Crohn's disease

The intestinal tract is the body's largest mucosal surface and permanently exposed to microbial and environmental signals. Maintaining a healthy intestine requires the presence of sentinel grounds keeper cells, capable of controlling immunity and tissue homeostasis through specialized functions. Intestinal macrophages are such cells and important players in steady-state functions and during acute and chronic inflammation. Crohn's disease, a chronic inflammatory condition of the intestinal tract is proposed to be the consequence of an altered immune system through microbial and environmental stimulation. This hypothesis suggests an involvement of macrophages in the regulation of this pathology. Within this chapter, we will discuss intestinal macrophage development and highlight data suggesting their implication in chronic intestinal pathologies like Crohn's disease.

The Specific Changes of Urine Raman Spectra Can Serve as Novel Diagnostic Tools for Disease Characteristics in Patients with Crohn’s Disease

Purpose

Crohn’s disease (CD) is a chronic recurrent intestinal inflammatory disease that requires repeated invasive examinations. Convenient and noninvasive diagnostic tools for CD are lacking. Surface-enhanced Raman spectroscopy (SERS) can rapidly provide specific metabolite information in various samples. Our previous study has showed urine Raman spectrum can distinguish CD patients from healthy controls noninvasively. In this study, we further investigated the value of urine Raman spectra on identifying the disease characterizations in patients with CD.

Patients and Methods

Urine samples were analyzed by SERS to acquire specific changes of the spectra from 100 active CD (aCD) patients and 88 inactive CD (iCD) patients. The accuracy of classifier models yielded by SERS was assessed by principal component analysis and support vector machine (PCA-SVM) to investigate spectral differences and disease characterizations.

Results

Given a panel of 16 specific Raman spectra, the classifier model was established to predict disease activity between patients with aCD and iCD and achieved higher efficacy than fecal calprotectin (AUC value, 0.864 vs 0.596, P=0.02). After leave-one-patient-out cross-validation, the classifier model still obtained 75.5% of accuracy. The correlation analysis showed it had negative correlation with endoscopic results (r=−0.616, P<0.0001). We further established the classifier model in identifying disease location to discriminate colonic-type from ileal-type CD with 63.6% of accuracy with the significantly increased intensity of 1643 cm⁻¹ band, and the model to predict the spectra changes of before and after treatment in tumor necrosis factor inhibitor responders with 91.2% of accuracy with a panel of 11 specific spectra. The metabolic changes of amino acids, proteins, lipids, and other compounds in urine levels were noted by SERS in patients with CD.

Conclusion

The specific changes of urine Raman spectra can reflect changes in urine metabolism. It has the potential value on being the promising diagnostic tool for disease characterizations in CD patients by a convenient and noninvasive way.

Cytokine autoantibodies are stable throughout the haematopoietic stem cell transplantation course and are associated with distinct biomarker and blood cell profiles

Cytokine-specific autoantibodies (c-aAbs) represent an emerging field in endogenous immunodeficiencies, and the immunomodulatory potential of c-aAbs is now well documented. Here, we investigated the hypothesis that c-aAbs affects inflammatory, immunoregulatory and injury-related processes and hence the clinical outcome of haematopoietic stem cell transplantation (HSCT). C-aAbs against IL-1α, IL-6, IL-10, IFNα, IFNγ and GM-CSF were measured in 131 HSCT recipients before and after (days + 7, + 14, + 28) HSCT and tested for associations with 33 different plasma biomarkers, leukocyte subsets, platelets and clinical outcomes, including engraftment, GvHD and infections. We found that c-aAb levels were stable over the course of HSCT, including at high titres, with few individuals seeming to acquire high-titre levels of c-aAbs. Both patients with stable and those with acquired high-titre c-aAb levels displayed significant differences in biomarker concentrations and blood cell counts pre-HSCT and at day 28, and the trajectories of these variables varied over the course of HSCT. No clinical outcomes were associated with high-titre c-aAbs. In this first study of c-aAbs in HSCT patients, we demonstrated that high-titre levels of c-aAb may both persist and emerge in patients over the course of HSCT and may be associated with altered immune biomarkers and cell profiles.

Prognostic biomarkers to identify patients likely to develop severe Crohn's disease: a systematic review

BACKGROUND

Identification of biomarkers that predict severe Crohn's disease is an urgent unmet research need, but existing research is piecemeal and haphazard.

OBJECTIVE

To identify biomarkers that are potentially able to predict the development of subsequent severe Crohn's disease.

DESIGN

This was a prognostic systematic review with meta-analysis reserved for those potential predictors with sufficient existing research (defined as five or more primary studies).

DATA SOURCES

PubMed and EMBASE searched from inception to 1 January 2016, updated to 1 January 2018.

REVIEW METHODS

Eligible studies were studies that compared biomarkers in patients who did or did not subsequently develop severe Crohn's disease. We excluded biomarkers that had insufficient research evidence. A clinician and two statisticians independently extracted data relating to predictors, severe disease definitions, event numbers and outcomes, including odds/hazard ratios. We assessed risk of bias. We searched for associations with subsequent severe disease rather than precise estimates of strength. A random-effects meta-analysis was performed separately for odds ratios.

RESULTS

In total, 29,950 abstracts yielded just 71 individual studies, reporting 56 non-overlapping cohorts. Five clinical biomarkers (Montreal behaviour, age, disease duration, disease location and smoking), two serological biomarkers (anti-Saccharomyces cerevisiae antibodies and anti-flagellin antibodies) and one genetic biomarker (nucleotide-binding oligomerisation domain-containing protein 2) displayed statistically significant prognostic potential. Overall, the strongest association with subsequent severe disease was identified for Montreal B2 and B3 categories (odds ratio 4.09 and 6.25, respectively).

LIMITATIONS

Definitions of severe disease varied widely, and some studies confounded diagnosis and prognosis. Risk of bias was rated as 'high' in 92% of studies overall. Some biomarkers that are used regularly in daily practice, for example C-reactive protein, were studied too infrequently for meta-analysis.

CONCLUSIONS

Research for individual biomarkers to predict severe Crohn's disease is scant, heterogeneous and at a high risk of bias. Despite a large amount of potential research, we encountered relatively few biomarkers with data sufficient for meta-analysis, identifying only eight biomarkers with potential predictive capability.

FUTURE WORK

We will use existing data sets to develop and then validate a predictive model based on the potential predictors identified by this systematic review. Contingent on the outcome of that research, a prospective external validation may prove clinically desirable.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016029363.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 45. See the NIHR Journals Library website for further project information.

Prognostic tools for identification of high risk in people with Crohn's disease: systematic review and cost-effectiveness study

BACKGROUND

Crohn's disease is a lifelong condition that can affect any segment of the gastrointestinal tract. Some people with Crohn's disease may be at higher risk of following a severe course of disease than others and being able to identify the level of risk a patient has could lead to personalised management.

OBJECTIVE

To assess the prognostic test accuracy, clinical impact and cost-effectiveness of two tools for the stratification of people with a diagnosis of Crohn's disease by risk of following a severe course of disease.

DATA SOURCES

The data sources MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were searched to inform the systematic reviews on prognostic accuracy, clinical impact of the prognostic tools, and economic evaluations. Additional data sources to inform the review of economic evaluations were NHS Economic Evaluation Database, Database of Abstracts of Reviews of Effects and the Health Technology Assessment Database.

REVIEW METHODS

Systematic reviews of electronic databases were carried out from inception to June 2019 for studies assessing the prognostic accuracy and clinical impact of the IBDX® (Crohn's disease Prognosis Test; Glycominds Ltd, Lod, Israel) biomarker stratification tool and the PredictSURE-IBD™ (PredictImmune Ltd, Cambridge, UK) tool. Systematic reviews of studies reporting on the cost-effectiveness of treatments for Crohn's disease were run from inception to July 2019. Two reviewers independently agreed on studies for inclusion, assessed the quality of included studies and validated the data extracted from studies. Clinical and methodological heterogeneity across studies precluded the synthesis of data for prognostic accuracy. A de novo economic model was developed to compare the costs and consequences of two treatment approaches - the 'top-down' and 'step-up' strategies, with step-up considered standard care - in people at high risk of following a severe course of Crohn's disease. The model comprised a decision tree and a Markov cohort model.

RESULTS

Sixteen publications, including eight original studies (n = 1478), were deemed relevant to the review of prognostic accuracy. Documents supplied by the companies marketing the prognostic tools were also reviewed. No study meeting the eligibility criteria reported on the sensitivity or specificity of the IBDX biomarker stratification tool, whereas one study provided estimates of sensitivity, specificity and negative predictive value for the PredictSURE-IBD tool. All identified studies were observational and were considered to provide weak evidence on the effectiveness of the tools. Owing to the paucity of data on the two tools, in the base-case analysis the accuracy of PredictSURE-IBD was assumed to be 100%. Accuracy of IBDX was assumed to be 100% in a scenario analysis, with the cost of the tests being the only difference between the analyses. The incremental analysis of cost-effectiveness demonstrated that top-down (via the use of PredictSURE-IBD in the model) is more expensive and generates fewer quality-adjusted life-years than step-up (via the standard care arm of the model).

LIMITATIONS

Despite extensive systematic searches of the literature, no robust evidence was identified of the prognostic accuracy of the biomarker stratification tools IBDX and PredictSURE-IBD.

CONCLUSIONS

Although the model indicates that standard care dominates the tests, the lack of evidence of prognostic accuracy of the two tests and the uncertainty around the benefits of the top-down and step-up treatment approaches mean that the results should be interpreted as indicative rather than definitive.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019138737.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 23. See the NIHR Journals Library website for further project information.

Clinical value of antibodies in inflammatory bowel diseases

Inflammatory bowel disease IBD (Crohns disease CD, ulcerative colitis UC) immune-mediated diseases of the digestive tract of unknown etiology. The basis of the pathogenesis of IBD is a violation of the protective mechanisms of the intestinal barrier as a result of a complex interaction of environmental factors, a genetic predisposition and defects in the activation of the immune response in the lymphoid tissue of the intestinal mucosa. Three groups of antibodies are detected in the sera of IBD patients: autoantibodies, antimicrobial antibodies and antibodies to peptide antigens. In CD, the most useful diagnostic markers are ASCA; in UC patients pANCA. Antibodies are not among the diagnostic criteria for CD and UC, the diagnosis of which is traditionally made on the basis of a complex of clinical, radiological, endoscopic and histological signs, but can be used as useful additional non-invasive markers for early diagnosis, assessment of clinical phenotypes, prognosis and effectiveness of treatment of these diseases.

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.

Secondary causes of inflammatory bowel diseases

Inflammatory bowel diseases (IBD), conventionally consist of Crohn’s disease (CD) and ulcerative colitis. They occur in individuals with high risk genotype for the disease in the setting of appropriate environmental factors. The pathogenesis of IBD involves a dysregulated autoimmune response to gut dysbiosis, which in turn is triggered due to exposure to various inciting environmental factors. But there is no clearly defined etiology of IBD and this type of disease is termed as “idiopathic IBD”, “classic IBD”, or “primary IBD”. We reviewed the current medical literature and found that certain etiological factors may be responsible for the development of IBD or IBD-like conditions, and we consider this form of de novo IBD as “secondary IBD”. Currently known factors that are potentially responsible for giving rise to secondary IBD are medications; bowel altering surgeries and transplantation of organs, stem cells or fecal microbiome. Medications associated with the development of secondary IBD include; immunomodulators, anti-tumor necrosis factor alpha agents, anti-interleukin agents, interferons, immune stimulating agents and checkpoint inhibitors. Colectomy can in some cases give rise to de novo CD, pouchitis of the ileal pouch, or postcolectomy enteritis syndrome. After solid organ transplantation or hematopoietic stem cell transplantation, the recipient may develop de novo IBD or IBD flare. Fecal microbiota transplantation has been widely used to treat patients suffering from recurrent Clostridium difficile infection but can also causes IBD flares.

High Levels of Anti-GM-CSF Antibodies in Deep Infiltrating Endometriosis

Endometriosis is a chronic hormono-dependent inflammatory gynecological disease. Endometriosis can be subdivided into three forms: superficial peritoneal implants, endometrioma, and deep infiltrating endometriosis (DIE). Inflammation is a typical feature of endometriosis with overproduction of prostaglandins, chemokines, and cytokines, like granulocyte-macrophage colony-stimulating factor (GM-CSF). GM-CSF is a hematopoietic growth factor and immune modulator which belongs to the group of cytokines that actively participate in inflammatory reactions. GM-CSF autoantibodies (Ab) are described in inflammatory diseases such as Crohn disease and ulcerative colitis where high concentrations of anti-GM-CSF Ab are correlated with severity, complications, and relapses. We have evaluated the presence of anti-GM-CSF Ab in the serum of 106 patients with endometriosis and 92 controls using a home-made enzyme-linked immunosorbent assay (ELISA) and correlated the results with the form and severity of the disease. We found that anti-GM-CSF Ab level is significantly increased in the sera of patients with endometriosis compared to controls and is associated with the severity of the disease especially in patients with deep endometriosis (p < 0.0001) with the highest number of lesions (p = 0.0034), including digestive involvement (p = 0.0041). We also found a correlation between these levels of anti-GM-CSF Ab and the number of lesions in DIE patients (r = 0.913). In this way, searching anti-GM-CSF Ab in endometriosis patient sera could be of value for patient follow-up and put further insight into the role of inflammation and of GM-CSF in endometriosis pathogenesis.

Non-SMC condensin I complex subunit D2 and non-SMC condensin II complex subunit D3 induces inflammation via the IKK/NF-κB pathway in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic, nonspecific intestinal inflammatory disease with undefined pathogenesis. Non-SMC condensin I complex subunit D2 (NCAPD2) and non-SMC condensin II complex subunit D3 (NCAPD3) play pivotal roles in chromosome assembly and segregation during both mitosis and meiosis. To date, there has been no relevant report about the functional role of NCAPD2 and NCAPD3 in UC.

AIM

To determine the level of NCAPD2/3 in intestinal mucosa and explore the mechanisms of NCAPD2/3 in UC.

METHODS

Levels of NCAPD2/3 in intestinal tissue were detected in 30 UC patients and 30 healthy individuals with in situ hybridization (ISH). In vitro, NCM60 cells were divided into the NC group, model group, si-NCAPD2 group, si-NCAPD3 group and si-NCAPD2+si-NCAPD3 group. Inflammatory cytokines were measured by ELISA, IKK and NF-κB were evaluated by western blot, and IKK nucleation and NF-κB volume were analyzed by immunofluorescence assay.

RESULTS

Compared with expression in healthy individuals, NCAPD2 and NCAPD3 expression in intestinal tissue was significantly upregulated (P < 0.001) in UC patients. Compared with levels in the model group, IL-1β, IL-6 and TNF-α in the si-NCAPD2, si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups were significantly downregulated (P < 0.01). IKK and NF-κB protein expression in the si-NCAPD2, si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups was significantly decreased (P < 0.01). Moreover, IKK nucleation and NF-κB volume were suppressed upon si-NCAPD2, si-NCAPD3 and si-NCAPD2+ si-NCAPD3 transfection.

CONCLUSION

NCAPD2/3 is highly expressed in the intestinal mucosa of patients with active UC. Overexpression of NCAPD2/3 promotes the release of pro-inflammatory cytokines by modulating the IKK/NF-κB signaling pathway.

Effective Use of the Laboratory in the Management of Patients with Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) comprises a group of chronic, intestinal inflammatory disorders, including ulcerative colitis and Crohn's disease. IBD is characterized by periods of relapse and remission. Long-term progressive intestinal inflammation can result in severe and devastating complications, such as intestinal strictures and/or fistulae. Immune suppressive medications with potent side effects are often used to control inflammation and limit disease activity. Laboratory tests guide various decisions in clinical management of IBD. We discuss tests used to diagnose IBD, assess for relapse or remission, monitor the effectiveness of therapeutic regimen, screen for the maintenance of health, and diagnose or prevent complications.

I_MDS: an inflammatory bowel disease molecular activity score to classify patients with differing disease-driving pathways and therapeutic response to anti-TNF treatment

Crohn’s disease and ulcerative colitis are driven by both common and distinct underlying mechanisms of pathobiology. Both diseases, exhibit heterogeneity underscored by the variable clinical responses to therapeutic interventions.

We aimed to identify disease-driving pathways and classify individuals into subpopulations that differ in their pathobiology and response to treatment.

We applied hierarchical clustering of enrichment scores derived from gene set variation analysis of signatures representative of various immunological processes and activated cell types, to a colonic biopsy dataset that included healthy volunteers, Crohn’s disease and ulcerative colitis patients. Patient stratification at baseline or after anti-TNF treatment in clinical responders and non-responders was queried. Signatures with significantly different enrichment scores were identified using a general linear model. Comparisons to healthy controls were made at baseline in all participants and then separately in responders and non-responders. Fifty-nine percent of the signatures were commonly enriched in both conditions at baseline, supporting the notion of a disease continuum within ulcerative colitis and Crohn’s disease. Signatures included T cells, macrophages, neutrophil activation and poly:IC signatures, representing acute inflammation and a complex mix of potential disease-driving biology. Collectively, identification of significantly enriched signatures allowed establishment of an inflammatory bowel disease molecular activity score which uses biopsy transcriptomics as a surrogate marker to accurately track disease severity. This score separated diseased from healthy samples, enabled discrimination of clinical responders and non-responders at baseline with 100% specificity and 78.8% sensitivity, and was validated in an independent data set that showed comparable classification. Comparing responders and non-responders separately at baseline to controls, 43% and 70% of signatures were enriched, respectively, suggesting greater molecular dysregulation in TNF non-responders at baseline. This methodological approach could facilitate better targeted design of clinical studies to test therapeutics, concentrating on patient subsets sharing similar underlying pathobiology, therefore increasing the likelihood of clinical response.

Patients exhibiting similar phenotypical characteristics, diagnosed with the same disease, exhibit variable response to therapeutics. This is a major health care issue, due to the increased patient suffering and the socioeconomical burden that occurs. Crohn’s disease and ulcerative colitis constitute good examples of inflammatory conditions, with sufferers responding differentially to existent therapeutics. Here, we identified disease-driving pathways and classified individuals into subpopulations that differ in their pathobiology and response to treatment. We utilized gene set variation analysis and transcriptomic data from inflammatory bowel disease sufferers to stratify patients at baseline or after anti-TNF treatment in clinical responders and non-responders. We explored gene signatures obtained from the literature, relevant to immune processes, which were significantly enriched in disease compared to healthy controls, as well as before and after treatment. Using these signatures, we established an inflammatory bowel disease molecular activity score, which allowed us to separate clinical responders and non-responders at baseline with high specificity and sensitivity. We validated the proposed approach in an independent data set, demonstrating comparable classification. This methodological approach may lead to better targeted design of clinical studies, allowing the selection of patient sharing similar underlying pathobiology, thus increasing the likelihood of clinical response to treatment.

ASCA and ANCA among Bedouin Arabs with inflammatory bowel disease, the frequency and phenotype correlation

Background

Serological markers used for diagnostic purposes and disease stratification in inflammatory bowel disease.

We aimed to investigate the frequency of ASCA and ANCA among Arab Bedouin IBD patients and its relationship to disease phenotype and course.

Methods

From cohort of 68, 25 Crohn’s disease (CD) and 25 Ulcerative colitis (UC) patients were recruited (72%). ASCA IgG was determined by ELISA assay. Immunofluorescence analysis of ANCA was performed.

Results

The IgG ASCA was detected in 13 (52%) of the CD patients and in three (12%) UC patients. The prevalence of ANCA among UC patients was positive with 76%, sub-grouped, atypical ANCA in 9 patients (36%), pANCA in six patients (24%) and cANCA in 4 patients (16%).

The detection of ASCA among CD patients was found not to be a reliable predictor of young age at diagnosis, gender, ileal involvement, anti-TNF treatment or surgery.

UC patients with positive ANCA were younger, mean age 40.2 ± 11.9 compared with 57.3 ± 21.2 (p = 0.03), and diagnosed at a younger age, 29.2 ± 11.8 compared with 43.5 ± 15.3 (p = 0.05).

Conclusion

The frequency of ASCA among Bedouin CD patients and ANCA among UC patients was high, however ASCA was not found to have a predictive value for disease phenotype or course. Positive ANCA in UC patients was predictive for younger age and age at diagnosis.

Molecular diagnosis and classification of inflammatory bowel disease

INTRODUCTION

Traditional diagnosis and classification of inflammatory bowel diseases (IBDs) have been based on clinical evaluation, laboratory testing, endoscopy, imaging, and histological examinations. With the advancement of medical technology, an increasing number of molecular surrogates are playing a key role in diagnosis, differential diagnosis, assessment of disease activity, prediction of clinical course, and therapeutic response of IBD. Areas covered: The authors review roles of both existing and emerging surrogates including genetic, serological, histologic, and fecal markers in diagnosis and classification of IBD. Comparisons in advantages and disadvantages of different markers have also been discussed. In addition, this review underscores controversial and unclear aspects which need further study. Expert commentary: IBD is characteristic of chronicity, relapse-remission and destructiveness. It is of great importance for clinicians to make an accurate diagnosis and classification. Current and new molecular markers perform well with acceptable sensitivity and specificity. The use of molecular markers in clinical practice needs to be further explored and then generalized. More work is warranted to identify novel useful markers and elucidate how to apply them together with current markers in clinical settings.

Plasma N-Glycan Signatures Are Associated With Features of Inflammatory Bowel Diseases

BACKGROUND & AIMS

Biomarkers are needed for early detection of Crohn's disease (CD) and ulcerative colitis (UC) or to predict patient outcomes. Glycosylation is a common and complex posttranslational modification of proteins that affects their structure and activity. We compared plasma N-glycosylation profiles between patients with CD or UC and healthy individuals (controls).

METHODS

We analyzed the total plasma N-glycomes of 2635 patients with inflammatory bowel diseases and 996 controls by mass spectrometry with a linkage-specific sialic acid derivatization technique. Plasma samples were acquired from 2 hospitals in Italy (discovery cohort, 1989 patients with inflammatory bowel disease [IBD] and 570 controls) and 1 medical center in the United States (validation cohort, 646 cases of IBD and 426 controls). Sixty-three glycoforms met our criteria for relative quantification and were extracted from the raw data with the software MassyTools. Common features shared by the glycan compositions were combined in 78 derived traits, including the number of antennae of complex-type glycans and levels of fucosylation, bisection, galactosylation, and sialylation. Associations of plasma N-glycomes with age, sex, CD, UC, and IBD-related parameters such as disease location, surgery and medication, level of C-reactive protein, and sedimentation rate were tested by linear and logistic regression.

RESULTS

Plasma samples from patients with IBD had a higher abundance of large-size glycans compared with controls, a decreased relative abundance of hybrid and high-mannose structures, lower fucosylation, lower galactosylation, and higher sialylation (α2,3- and α2,6-linked). We could discriminate plasma from patients with CD from that of patients with UC based on higher bisection, lower galactosylation, and higher sialylation (α2,3-linked). Glycosylation patterns were associated with disease location and progression, the need for a more potent medication, and surgery. These results were replicated in a large independent cohort.

CONCLUSIONS

We performed high-throughput analysis to compare total plasma N-glycomes of individuals with vs without IBD and to identify patterns associated with disease features and the need for treatment. These profiles might be used in diagnosis and for predicting patients' responses to treatment.

Emerging concepts in non-invasive monitoring of Crohn's disease

Inflammatory bowel disease (IBD) is an umbrella term for Crohn's disease (CD) and ulcerative colitis (UC). In light of evolving epidemiology of CD, its clinical management is still complex and remains a challenge for contemporary physicians. With the advent of new diagnostic and treatment paradigms, there is a growing need for new biomarkers to guide decision-making, differential diagnosis, disease activity monitoring, as well as prognosis. However, both clinical and endoscopic scoring systems, widely utilized for disease monitoring and prognosis, have drawbacks and limitations. In recent years, biochemical peptides have become available for IBD monitoring and more frequently used as surrogate markers of gut inflammation. Emerging concepts that revolve around molecular, stem cell, epigenetic, microbial or metabolomic pathways associated with vascular and epithelial gut barrier could lead to development of new CD biomarkers. Measurement of cell-derived microvesicles (MVs) in the blood of IBD patients is another emerging concept helpful in future disease management. In this review, we discuss novel concepts of non-invasive biomarkers, which may become useful in monitoring of CD activity and prognosis. We discuss metabolomics as a new powerful tool for clinicians to guide differential IBD diagnosis. In the coming years, new developments of prognostic tools are expected, aiming for breakthroughs in the management of patients with CD.

The value of serum antibodies in differentiating inflammatory bowel disease, predicting disease activity and disease course in the newly diagnosed patient

BACKGROUND

Data on serum antibodies in untreated adult inflammatory bowel disease (IBD) patients at diagnosis are scarcely available, and results on the stability of antibody presence over time are inconsistent. Our aim was to investigate antibodies in newly diagnosed, untreated IBD patients in relation to disease phenotype and course. Furthermore, we analyzed antibody presence over time.

METHODS

Baseline anti-Saccharomyces cerevisiae antibodies (ASCA), anti-chitobioside carbohydrate antibodies (ACCA), anti-laminaribioside carbohydrate antibodies (ALCA) and anti-mannobioside carbohydrate antibodies (AMCA) were measured with enzyme-linked immunosorbent assays and perinuclear anti-neutrophilic cytoplasmic antibodies (pANCA) was measured by indirect immunofluorescence in serum of 120 untreated IBD patients at diagnosis and 19 healthy controls. Antibodies were related to disease outcomes. Serial measurements were available in 71 patients.

RESULTS

The combination of pANCA and ASCA enabled good discrimination between UC and CD (p = .004). Antibody presence was relatively stable over time, even though there were significant changes in concentrations. There was a trend towards larger fluctuations in concentration with immunosuppressive medication. Baseline pANCA in UC patients correlated with calprotectin values (rho = .545, p = .019) and change in pANCA status over time was associated with disease activity at that moment. No associations were found with antibodies at diagnosis and disease outcomes.

CONCLUSION

Antibody profiles at diagnosis support the distinction between CD and UC. Anti-glycan antibodies are reasonably stable over time, but may fluctuate under the influence of immunosuppressive treatment which may explain the inconsistency in findings hitherto. The appearance or disappearance of pANCA antibodies during follow-up correlated with disease activity in UC and may be used in disease monitoring.

Autoantibodies Against Glycoprotein 2 Isoforms in Pediatric Patients with Inflammatory Bowel Disease

BACKGROUND

Anti-Glycoprotein 2 (GP2) antibodies are associated with a more complicated course of Crohn's disease (CD) in adults. Four different GP2 isoforms with different length and antibody-binding sites have been identified so far but not been explored in serological studies. We aimed to investigate the diagnostic utility of autoantibodies against all 4 isoforms of GP2 in an exclusively pediatric population for the first time.

METHODS

We included 278 children and adolescents with inflammatory bowel disease: 164 with CD, 114 with ulcerative colitis, 83 disease controls (acute gastrointestinal infection, nonspecific gastrointestinal functional disorders), and 219 healthy controls. Sera were tested for anti-GP2 antibodies using 4 different isoforms of GP2 for anti-Saccharomyces cerevisiae antibodies, antineutrophil cytoplasmic antibodies, and pancreatic antibodies.

RESULTS

Anti-GP2 antibodies were significantly more prevalent in patients with CD than in ulcerative colitis and controls. We found a sensitivity of 38% (with a specificity of 95%) for anti-GP2 IgG against isoform 4 in CD. Anti-GP2 IgA against isoform 1 and anti-GP2 IgG against isoform 4 possessed the best diagnostic values for identification of CD. For the differentiation of CD from ulcerative colitis anti-GP2 IgG against isoforms 3 and 4 proved to be most accurate markers. Anti-GP2 antibodies were associated with a more complicated disease behavior and bowel surgery in CD. In a subgroup of patients with CD, anti-GP2 IgG against isoform 4 proved to be a relatively stable marker over time independent of disease activity.

CONCLUSIONS

Anti-GP2 antibodies against different isoforms are specific markers for CD and for different phenotypes in pediatric inflammatory bowel disease.

An update on diagnostic and prognostic biomarkers in inflammatory bowel disease

INTRODUCTION

Diagnosis of the chronic inflammatory bowel diseases relies upon initial recognition of an inflammatory condition, followed by definitive endoscopic, histological and radiological investigations. Various biomarkers are available to assist with initial elucidation of an inflammatory process: these also have important roles after diagnosis in monitoring and ongoing assessment of progress. Areas covered: Various inflammatory markers, serological tests and genetic analyses may be helpful in predicting the course of disease in the coming months. This review provides an update on the current understanding and knowledge about these markers. It also highlights key gaps and identifies aspects that require further study. Expert commentary: Our current approach to the application of non-invasive biomarkers is rudimentary. Further work is required to elucidate the roles of the various markers.

Identification of Antibody Against SNRPB, Small Nuclear Ribonucleoprotein-Associated Proteins B and B', as an Autoantibody Marker in Crohn's Disease using an Immunoproteomics Approach

BACKGROUND

Current non-invasive biomarkers for Crohn's disease are limited in their utility. Progress in identifying individual autoantigens and autoantibodies in Crohn's disease has been challenging due to limitations of available immunoassays.

AIMS

Our aim was to identify autoantibodies associated with Crohn's disease that may be useful in diagnosis and management using an innovative protein array technology, namely nucleic acid programmable protein arrays [NAPPA].

METHODS

Serum samples of 96 patients with established Crohn's disease and 96 healthy controls were included and evenly split into discovery and validation sets randomly. Autoantibodies of both IgG and IgA classes were profiled against ~1900 human proteins in the discovery set on NAPPA. Autoantibodies discovered to be Crohn's disease-specific were further validated in the independent validation set by enzyme-linked immunosorbent assay.

RESULTS

Overall, reactivity of IgG autoantibodies was stronger than that of IgA autoantibodies; however, IgA autoantibodies showed greater differential reactivity between cases and controls. Four IgA autoantibodies against SNRPB, PRPH, PTTG1 and SNAI1 were newly identified with sensitivities above 15% at 95% specificity, among which anti-SNRPB-IgA had the highest sensitivity of 24.0%. Autoantibodies associated with specific disease subtypes were also found.

CONCLUSIONS

As one of the first studies to use immunoproteomics for the identification of autoantibodies in Crohn's disease, our results support the utility of NAPPA in implementing future expanded studies with better coverage of the human proteome and microbial proteomes relevant to Crohn's disease and identifying antibody markers that may have clinical impact in diagnosis and management.

Retrospective evaluation of the clinical utility of serological biomarkers in Chinese patients with inflammatory bowel disease: 2-year clinical experience

BACKGROUND

Antibodies to saccharomyces cerevisiae (ASCA), antibodies to perinuclear anti-neutrophil cytoplasmic (pANCA), pancreatic autoantibodies (PAB) and antibodies against intestinal goblet cells (GAB) are important in diagnosing Crohn's disease (CD) and ulcerative colitis (UC). However, little is known about their diagnostic value in real clinical practice in China. This retrospective study aimed to present our 2-year clinical experience with those biomarkers in diagnosis of CD and UC.

METHODS

A total of 140 patients with UC, 128 patients with CD, and 224 patients with intestinal associated diseases as disease controls were included. Serum ASCA were determined by ELISA. Serum pANCA, GAB, and PAB were tested by indirect immunofluorescent assay. Retrospective review of laboratory results and clinical information was performed.

RESULTS

ASCA and ASCA+/pANCA- showed poor abilities in differentiating CD from UC, CD from intestinal Behçet's disease (BD), or CD from intestinal tuberculosis (ITB). In contrast, PAB exhibited good capacities in differentiating CD from UC, CD from intestinal BD, and CD from ITB. IgG pANCA demonstrated a high sensitivity and specificity in differentiating UC from CD. pANCA+/ASCA- or pANCA+/PAB- displayed a high sensitivity and specificity in differentiating UC from CD. GAB showed poor potential in differentiating UC from CD. PAB were positively correlated with early disease onset, ileocolonic disease, and perianal disease in CD patients.

CONCLUSIONS

Our data suggest that pANCA and PAB are helpful in diagnosis of UC and CD, respectively, while ASCA and GAB were not. Our findings indicate a clear need for additional biomarkers for diagnosis of CD in China.

Evolution, immunity and the emergence of brain superautoantigens

While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to those of the neural repertoires (i.e. the distinct neuronal populations and synaptic circuits supporting cognitive and sensorimotor functions). Clinical implications and future experimental insights are also presented and discussed.

IBD immunopathogenesis: A comprehensive review of inflammatory molecules

Inflammatory molecules play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) such as ulcerative colitis and Crohn's disease, both of which are chronic inflammatory conditions of the gastrointestinal tract. Abnormal expressions of pro- and anti-inflammatory molecules have been described to cause an imbalance to the gut innate and adaptive immunity, and recently a large portion of research in IBD has been geared towards identifying novel molecules that may be used as potential therapeutic targets. Understanding of these inflammatory molecules has suggested that although ulcerative colitis and Crohn's disease share many common clinical symptoms and signs, they are in fact two separate clinical entities characterized by different immunopathogenesis. In this review, we comprehensively discuss the roles of numerous inflammatory molecules including but not limited to cytokines, chemokines, inflammasomes, microRNAs and neuropeptides and their expression status in ulcerative colitis and Crohn's disease in relation to their effects on the overall intestinal inflammatory process.

Distinct Anti-IFI16 and Anti-GP2 Antibodies in Inflammatory Bowel Disease and Their Variation with Infliximab Therapy

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the gut, partly driven by defects in the expression and function of pattern recognition receptors, including the IFI16 protein. Because this protein is a target for autoantibodies and its aberrant expression was reported in colonic mucosa from active patients with ulcerative colitis, we studied its expression and specific seroresponse in patients with IBD before and after infliximab (IFX) therapy.

METHODS

Anti-IFI16 antibodies (IgG and IgA subtypes) were measured in the sera of 74 patients with IBD: 48 patients with Crohn's disease (CD) and 26 patients with ulcerative colitis, prospectively harvested before and after IFX therapy. Anti-GP2 antibodies (both IgG and IgA subtypes) were also tested for comparison. The patient antibody statuses were qualitatively and quantitatively associated with disease phenotype and response to IFX therapy.

RESULTS

Significantly higher titers of anti-IFI16 IgG were found in both CD and ulcerative colitis patients compared with healthy controls. Anti-IFI16 IgA titers were also present in patients with CD. Anti-GP2 IgG subtype titers were significantly increased in patients with CD, as were IgA subtype titers. Significant changes in anti-IFI16 IgG subtype titers were observed after IFX in patients with CD who correlated with clinical remission or response.

CONCLUSIONS

Our results highlight the importance of IFI16 in IBD pathogenesis showing that its de novo overexpression in the gut epithelial cells leads to a breakdown in immune tolerance and the subsequent development of specific autoantibodies. Anti-IFI16 IgG antibodies hold the potential to serve as a biomarker of response to IFX therapy.

Crohn's Disease: Evolution, Epigenetics, and the Emerging Role of Microbiome-Targeted Therapies

Crohn's disease (CD) is a chronic, systemic, immune-mediated inflammation of the gastrointestinal tract. Originally described in 1932 as non-caseating granulomatous inflammation limited to the terminal ileum, it is now recognized as an expanding group of heterogeneous diseases defined by intestinal location, extent, behavior, and systemic extraintestinal manifestations. Joint diseases, including inflammatory spondyloarthritis and ankylosing spondylitis, are the most common extraintestinal manifestations of CD and share more genetic susceptibility loci than any other inflammatory bowel disease (IBD) trait. The high frequency and overlap with genes associated with infectious diseases, specifically Mendelian susceptibility to mycobacterial diseases (MSMD), suggest that CD may represent an evolutionary adaptation to environmental microbes. Elucidating the diversity of the enteric microbiota and the protean mucosal immune responses in individuals may personalize microbiome-targeted therapies and molecular classifications of CD. This review will focus on CD's natural history and therapies in the context of epigenetics, immunogenetics, and the microbiome.

The Role of Laboratory Tests in Crohn's Disease

In the past, laboratory tests were considered of limited value in Crohn's disease (CD). In the era of biologics, laboratory tests have become essential to evaluate the inflammatory burden of the disease (C-reactive protein, fecal calprotectin) since symptoms-based scores are subjective, to predict the response to pharmacological options and the risk of relapse, to discriminate CD from ulcerative colitis, to select candidates to anti-tumor necrosis factors [screening tests looking for hepatitis B virus and hepatitis C virus status and latent tuberculosis], to assess the risk of adverse events (testing for thiopurine metabolites and thiopurine-methyltransferase activity), and to personalize and optimize therapy (therapeutic drug monitoring). Pharmacogenetics, though presently confined to the assessment of thiopurineme methyltransferase polymorphisms and hematological toxicity associated with thiopurine treatment, is a promising field that will contribute to a better understanding of the molecular mechanisms of the variability in response to the drugs used in CD with the attempt to expand personalized care and precision medicine strategies.

ANCA-associated vasculitis - clinical utility of using ANCA specificity to classify patients

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a heterogeneous group of rare syndromes characterized by necrotizing inflammation of small and medium-sized blood vessels and the presence of ANCAs. Several clinicopathological classification systems exist that aim to define homogeneous groups among patients with AAV, the main syndromes being microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic GPA (EGPA). Two main types of ANCA can be detected in patients with AAV. These ANCAs are defined according to their autoantigen target, namely leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). Patients with GPA are predominantly PR3-ANCA-positive, whereas those with MPA are predominantly MPO-ANCA-positive, although ANCA specificity overlaps only partially with these clinical syndromes. Accumulating evidence suggests that ANCA specificity could be better than clinical diagnosis for defining homogeneous groups of patients, as PR3-ANCA and MPO-ANCA are associated with different genetic backgrounds and epidemiology. ANCA specificity affects the phenotype of clinical disease, as well as the patient's initial response to remission-inducing therapy, relapse risk and long-term prognosis. Thus, the classification of AAV by ANCA specificity rather than by clinical diagnosis could convey clinically useful information at the time of diagnosis.

Current landscape of protein glycosylation analysis and recent progress toward a novel paradigm of glycoscience research

This review covers the basics and some applications of methodologies for the analysis of glycoprotein glycans. Analytical techniques used for glycoprotein glycans, including liquid chromatography (LC), capillary electrophoresis (CE), mass spectrometry (MS), and high-throughput analytical methods based on microfluidics, were described to supply the essentials about biopharmaceutical and biomarker glycoproteins. We will also describe the MS analysis of glycoproteins and glycopeptides as well as the chemical and enzymatic releasing methods of glycans from glycoproteins and the chemical reactions used for the derivatization of glycans. We hope the techniques have accommodated most of the requests from glycoproteomics researchers.

How to predict clinical relapse in inflammatory bowel disease patients

Inflammatory bowel diseases have a natural course characterized by alternating periods of remission and relapse. Disease flares occur in a random way and are currently unpredictable for the most part. Predictors of benign or unfavourable clinical course are required to facilitate treatment decisions and to avoid overtreatment. The present article provides a literature review of the current evidence on the main clinical, genetic, endoscopic, histologic, serologic and fecal markers to predict aggressiveness of inflammatory bowel disease and discuss their prognostic role, both in Crohn’s disease and ulcerative colitis. No single marker seems to be reliable alone as a flare predictor, even in light of promising evidence regarding the role of fecal markers, in particular fecal calprotectin, which has reported good results recently. In order to improve our daily clinical practice, validated prognostic scores should be elaborated, integrating clinical and biological markers of prognosis. Finally, we propose an algorithm considering clinical history and biological markers to intercept patients with high risk of clinical relapse.

Autoimmunity in Crohn's Disease-A Putative Stratification Factor of the Clinical Phenotype

Inflammation in inflammatory bowel diseases (IBD) has been linked to a loss of tolerance to self-antigens suggesting the existence of autoantibodies in specific disease phenotypes. However, the lack of clearly defined autoantigenic targets has slowed down research. Genome-wide association studies have identified an impressive number of immune-related susceptibility loci for IBD with no clearly discernible pattern among them. Growing evidence supports the hypothesis that innate immune responses to a low-diversity and impaired gut microbiota may be of key importance in initiating and perpetuating chronic inflammation in IBD. Increasing evidence suggests that reduced microbial diversity and microbial-mucosal epithelium interaction (including adhesion and clearance) are critically involved in IBD pathogenesis. Along these lines the discovery of autoantigenic targets in Crohn's disease (CD) has refocused research in IBD on the possible role of autoimmune responses. The identification of the major zymogen granule membrane glycoprotein 2 (GP2) as an autoantigen in CD patients and its proposed role in the sensing of the microbiota lends credence to this trend. Loss of tolerance to GP2 occurs in up to 40% of patients with CD. Corresponding autoantibodies appear to be associated with distinct disease courses (types or phenotypes) in CD. Here, we critically review autoantibodies in CD for their impact on clinical practice and future IBD research. The immunomodulatory role of GP2 in innate and adaptive intestinal immunity is also discussed.

GM-CSF and the role of myeloid regulatory cells in the pathogenesis and treatment of Crohn's disease

Background

Intestinal monocytes/macrophages sustain the intestinal immune homeostasis and might be an attractive therapeutic target for the management of inflammatory bowel disease (IBD). Granulocyte macrophage colony-stimulating factor (GM-CSF) exerts beneficial effects on intestinal inflammation and promotes signal transducer and activator of transcription 3 (STAT3)-mediated expansion of myeloid-derived suppressor cells (MDSCs). However, the full action mechanism of GM-CSF, and especially whether monocytes mediate its therapeutic effects in vivo, had not been previously elucidated.

Conclusions

This review article summarizes recent developments in the immunology of mucosal diseases and describes new aspects of the role of myeloid regulatory cells in IBD and the function of GM-CSF in maintaining the intestinal immune homeostasis in Crohn’s disease (CD). This review article highlights the exploration of stimulating in addition to suppressive therapies for patients with IBD and underpins that myeloid regulatory cells might become a promising novel cell-based therapeutic option.

G-CSF and GM-CSF in Neutropenia

G-CSF and GM-CSF are used widely to promote the production of granulocytes or APCs. The U.S. Food and Drug Administration approved G-CSF (filgrastim) for the treatment of congenital and acquired neutropenias and for mobilization of peripheral hematopoietic progenitor cells for stem cell transplantation. A polyethylene glycol-modified form of G-CSF is approved for the treatment of neutropenias. Clinically significant neutropenia, rendering an individual immunocompromised, occurs when their number is <1500/μl. Current guidelines recommend their use when the risk for febrile neutropenia is >20%. GM-CSF (sargramostim) is approved for neutropenia associated with stem cell transplantation. Because of its promotion of APC function, GM-CSF is being evaluated as an immunostimulatory adjuvant in a number of clinical trials. More than 20 million persons have benefited worldwide, and >$5 billion in sales occur annually in the United States.

Host-microbiome interaction in Crohn’s disease: A familiar or familial issue?

An impaired interaction between the gut and the intestinal microbiome is likely to be the key element in the pathogenesis of Crohn’s disease (CD). Family studies have provided invaluable information on CD pathogenesis and on its etiology. Relatives share the same genetic risk of developing the disease as affected subjects. Relatives also exhibit similar features relating to their host-microbiome interaction, namely genetic variants in loci involved in detecting bacteria, a greater sero-reactivity to microbial components, and an impaired intestinal permeability. The burden of environmental factors such as cigarette smoking and dysbiosis also seems to be particularly relevant in these genetically predisposed subjects. Diet is emerging as an important factor and could account for the changing epidemiology of CD in recent years. Despite the pivotal role of genetics in the disease’s pathogenesis (especially in familial CD), screening tests in healthy relatives cannot be recommended.

Maintenance therapy for Crohn's disease: should it be indefinite?

Crohn's disease (CD) is a chronic, persistent, and destructive disorder with different forms of clinical behavior and the disease appears to be progressive over the long term. Providing greater levels of mucosal healing and resolution of clinical symptoms may modify the course of CD. This will often necessitate long-term therapy with immunosuppressant or biological therapies. Both these classes of drugs have side-effects and the latter are also very expensive. Identification of a subgroup of patients with a low risk of relapse and validation of the relevant predictors in various cohort studies are the key points to be able to cease immunosuppressant and/or biological therapy in patients with CD in stable remission. The individual parameters 'mucosal healing', 'deep remission', 'fecal calprotectin', and 'C-reactive protein' or various combinations of these parameters seem to be promising tools for predicting successful withdrawal of maintenance therapy.

Rediscovery of the Anti-Pancreatic Antibodies and Evaluation of their Prognostic Value in a Prospective Clinical Cohort of Crohn's Patients: The Importance of Specific Target Antigens [GP2 and CUZD1]

BACKGROUNDS

Glycoprotein 2[GP2] and CUB zona pellucida-like domain 1[CUZD1] belong to protein families involved in gut innate immunity processes and have recently been identified as specific targets of anti-pancreatic autoantibodies [PAbs] in Crohn's disease[CD]. We aimed to determine the prognostic potential of novel target-specific PAbs regarding long-term disease course of an adult CD patient cohort.

METHODS

Sera of 458 consecutive well-characterised IBD patients from a single referral IBD centre were tested by enzyme-linked immunosorbent assay [ELISA] with isoform 4 of recombinant GP2 [anti-MZGP2 and anti-GP2 IgA/IgG] and indirect immunofluorescence test [IIFT] system with GP2 and CUZD1 expressing transfected HEK 293 cells [anti-rPAg2 and rPAg1 IgA/IgG]. Clinical data were available on complicated disease or surgical interventions as well as disease activity and medical treatment during the prospective follow-up [median, 108 months].

RESULTS

Totals of 12.4% and 20.8% of CD patients were positive for IgA/IgG type of anti-GP2 and anti-CUZD1, respectively, with a significant difference compared with UC [p < 0.01]. Antibody status was stable over time. Agreement among three different anti-GP2 assays was good. Positivity for PAbs, mainly IgA subtypes, predicted a faster progression towards complicated disease course. In Kaplan-Meier analysis, time to surgery or development of perianal disease was associated with anti-GP2 IgA [pLogRank < 0.01] or anti-CUZD1 IgA [pLogRank < 0.001] positivity, respectively. Anti-CUZD1 IgA remained an independent predictor in the multivariate Cox-regression model (hazard ratio [HR]: 3.43, 95% confidence interval [CI]: 1.68-7.02, p < 0.001).

CONCLUSIONS

The present study has shown that specific PAbs [especially IgA subtype] predict complicated disease course including the development of perianal disease in CD.

Loss and Gain of Tolerance to Pancreatic Glycoprotein 2 in Celiac Disease

BACKGROUND

Autoantibodies against pancreatic secretory-granule membrane glycoprotein 2 (GP2) have been demonstrated in patients with Crohn's disease but recently also with celiac disease (CD). Both entities are characterized by intestinal barrier impairment with increased gut permeability. Pathophysiological hallmark of CD is a permanent loss of tolerance to alimentary gliadin and a transient loss of tolerance to the autoantigen human tissue transglutaminase (tTG). Therefore, we explored the behavior of loss of tolerance to GP2 reported in CD.

METHODS

We assessed prevalences and levels of autoantibodies against GP2, CD-specific antibodies to endomysial antigens and tTG as well as Crohn's disease-specific anti-Saccharomyces cerevisiae antibodies in sera of 174 patients with active CD, 84 patients under gluten-free diet (GFD) and 129 controls. Furthermore, we looked for an association between anti-GP2 antibody positivity and degree of mucosal damage in CD.

RESULTS

We found significantly elevated anti-GP2 IgA positivity in active CD patients (19.5%) compared to CD patients under GFD (0.0%) and controls (5.4%, p < 0.001, respectively). Anti-GP2 IgA levels correlated significantly with CD-specific antibodies (p < 0.001). Anti-GP2 autoantibody positivity disappeared under GFD similarly to CD-specific autoantibodies against tTG and endomysial antigens. For the first time, IgA antibody levels to GP2 are demonstrated to be associated with degree of villous atrophy according to Marsh classification.

CONCLUSIONS

Anti-GP2 IgA seems to be associated with disease activity in a distinct subgroup of patients with CD. The observed loss of tolerance to GP2 in a subset of patients with CD is transient and disappears under GFD.