Antiglycan antibodies as serological markers in the differential diagnosis of inflammatory bowel disease

The Correlation between New Serological Markers and Disease Phenotype and Activation in Inflammatory Bowel Disease

Background: The aim of the study is to assess the correlation between a new antibody panel that is developed against glycans on Crohn's disease (CD) and ulcerative colitis (UC) differentiative diagnosis and disease properties. Methods: In the study, 137 CD and 122 UC patients and 90 controls were included. Anti-saccharomyces cerevisiae IgG (ASCA), anti-laminaribioside IgG (ALCA), anti-chitobioside IgA (ACCA), and anti-mannobioside IgG (AMCA) were tested in serum. Results: While at least 1 of the other 3 serological markers was positive in 89% of ASCA-positive patients, at least 1 of the other 3 serological markers was positive in 77% of ASCA-negative patients. Positivity ratio for a single anticarbohydrate was ALCA 18 (22%), ACCA 5 (12%), and AMCA 16 (23%). A significant correlation was found between ASCA positivity (P<0.001) in operated patients and between ASCA, ALCA, and ACCA positivity (P<0.05) in patients with stricturing and fistulizing CD. According to the ROC analysis, ASCA was found to have the highest area under the curve (0.70-0.82) (correlation coefficient interval 95%). A significant correlation was found between ASCA, ALCA, and ACCA positivity and high serum antibody levels and disease activation (P<0.05). Conclusion: ASCA, ALCA, and ACCA were found to be correlated with the disease complication and activation in CD. ASCA and ALCA were determined as the best markers in the differentiation between CD and UC.

The Role of Biomarkers in Surgery for Ulcerative Colitis: A Review

Ulcerative colitis (UC) is an inflammatory condition that generally affects the rectum and extends proximally into the colon in a continuous, distal-to-proximal pattern. Surgical resection (total proctocolectomy) is the only cure for UC and is often necessary in managing complicated or refractory disease. However, recent advances in biologically targeted therapies have resulted in improved disease control, and surgery is required in only a fraction of cases. This ever-increasing array of options for medical management has added complexity to surgical decision-making. In some circumstances, the added time required to ensure failure of medical therapy can delay colectomy in patients who will ultimately need it. Indeed, many patients with severe disease undergo trials of multiple medical therapies prior to considering surgery. In severe cases of UC, continued medical management has been associated with a delay to surgical intervention and higher rates of morbidity and mortality. Biomarkers represent a burgeoning field of research, particularly in inflammatory bowel disease and cancer. This review seeks to highlight the different possible settings for surgery in UC and the role various biomarkers might play in each.

Serum complement C3 and α2-macroglobulin are potentially useful biomarkers for inflammatory bowel disease patients

Aims

Ulcerative colitis (UC), characterized by chronic inflammation and its recurrence in the large intestine, is well known as inflammatory bowel disease (IBD). Suitable biomarkers specific for UC are poorly understood till date. We aimed to discover novel serum biomarkers for UC and identify good indicators that reflected the severity of UC.

Main methods

Serum samples were obtained from out-patients with IBD (n = 101) and healthy volunteers (HVs, n = 101). Serum proteins were subjected to high performance liquid chromatography (HPLC) and sodium dodecyl sulfate-electrophoresis (SDS-PAGE) analysis. After electrophoresis, proteins in the gel were identified by mass spectrometry. Further, the protein concentration was measured by enzyme-linked immunosorbent assays (ELISAs). Based on the results, correlations between the serum levels of these proteins and the disease activity index scores for UC were statistically evaluated.

Principal findings

HPLC showed that chromatograms of serum proteins from HVs apparently differed from those of patients with IBD. Eleven protein bands, which were different in their protein concentrations from those in HVs, were separated by SDS-PAGE accordingly. Among them, complement C3 (c-C3) and α₂-macroglobulin (α₂-MG), with high protein scores, were identified by mass spectrometry. The serum concentration of c-C3 in patients with IBD was higher than that in HVs. However, the level of α₂-MG in patients with IBD was significantly lower than that in HVs. Hence, the serum levels of c-C3 and α₂-MG could be good indicators of the severity of UC.

Conclusion

Serum c-C3 and α₂-MG are suitable biomarkers for monitoring the condition of patients with UC.

Expression of Chemokine CCL28 in Ulcerative Colitis Patients

Background/Aims

Ulcerative colitis (UC) is an inflammatory bowel disease for which new serological markers are required. The purpose of this study was to assess the role of the mucosa-associated epithelial chemokine CCL28 in UC.

Methods

The study included 50 patients; of these, 25 were patients with UC, and 25 were healthy controls. The levels of serum CCL28 were analyzed using enzyme-linked immunosorbent assay. CCL28 expression was analyzed by immunohistochemistry (IHC) in 15 representative colon tissues biopsied based on disease activity (UC patients with severe activity, five samples; UC patients with mild activity, five samples; healthy controls, five samples).

Results

The serum CCL28 levels were remarkably higher (p<0.05) in patients with UC (median, 235.7 pg/mL; IQR, 63.8 to 117.2 pg/mL) than in healthy controls (median, 48.9, pg/mL; IQR, 35.9 to 42.0 pg/mL). However, there was no significant difference in serum CCL28 according to disease extent or activity. In contrast, IHC analysis revealed a significant difference in CCL28 consistent with disease status, disease extent, and disease activity.

Conclusions

CCL28 could be useful for diagnosing UC. However, further validations of CCL28 on disease activity and severity are needed.

Amplification and Preparation of Cellular O-Glycomes for Functional Glycomics

Mucin-type O-glycans play key roles in many cellular processes, and they are often altered in human diseases. A major challenge in studying the role of O-glycans through functional O-glycomics is the absence of a complete repertoire of the glycans that comprise the human O-glycome. Here we describe a cellular O-glycome preparation strategy, Preparative Cellular O-Glycome Reporter/Amplification (pCORA), that introduces 4-N₃-Bn-GalNAc(Ac)₃ as a novel precursor in large-scale cell cultures to generate usable amounts of O-glycans as a potential O-glycome factory. Cultured human non-small cell lung cancer (NSCLC) A549 cells take up the precursor, which is extended by cellular glycosyltransferases to produce 4-N₃-Bn-α-O-glycans that are secreted into the culture medium. The O-glycan derivatives can be clicked with a fluorescent bifunctional tag that allows multidimensional HPLC purification and production of a tagged glycan library, representing the O-glycome of the corresponding cells. We obtained ∼5% conversion of precursor to O-glycans and purified a tagged O-glycan library of over 100 O-glycan derivatives, many of which were present in >100 nmol amounts and were sequenced by sequential MS fragmentation (MSⁿ). These O-glycans were successfully printed onto epoxy glass slides as an O-glycome shotgun microarray. We used this novel array to explore binding activity of serum IgM in healthy persons and NSCLC patients at different cancer stages. This novel strategy provides access to complex O-glycans in significant quantities and may offer a new route to discovery of potential diagnostic disease biomarkers.

Oral Manifestations of Inflammatory Bowel Disease and the Role of Non-Invasive Surrogate Markers of Disease Activity

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), can be associated with several extra-intestinal manifestations requiring a multidisciplinary management both in terms of work-up and therapy. Oral lesions are common in patients with IBD, with a prevalence ranging from 5% to 50%. These can represent an oral location of IBD as well as a side-effect of drugs used to treat the intestinal disease. Oral manifestations, occurring in patients with IBD, can be divided in nonmalignant, specific, and non-specific ones, and malignant lesions. While there is undoubtedly a need to search for an IBD in patients with oral lesions associated with intestinal symptoms, the work-up of those with an exclusive oral lesion should be personalized. Fecal calprotectin is a non-invasive marker of intestinal inflammation and may be used to select which patients need to undergo endoscopic examination, thereby avoiding unnecessary investigations. The pharmacological armamentarium to treat oral lesions associated with IBD includes topical or systemic corticosteroids, immunosuppressive agents, and biologic drugs.

Novel biomarkers of fibrosis in Crohn’s disease

Fibrosis represents a major challenge in Crohn’s disease (CD), and many CD patients will develop fibrotic strictures requiring treatment throughout their lifetime. There is no drug that can reverse intestinal fibrosis, and so endoscopic balloon dilatation and surgery are the only effective treatments. Since patients may need repeated treatments, it is important to obtain the diagnosis at an early stage before strictures become symptomatic with extensive fibrosis. Several markers of fibrosis have been proposed, but most need further validation. Biomarkers can be measured either in biological samples obtained from the serum or bowel of CD patients, or using imaging tools and tests. The ideal tool should be easily obtained, cost-effective, and reliable. Even more challenging is fibrosis occurring in ulcerative colitis. Despite the important burden of intestinal fibrosis, including its detrimental effect on outcomes and quality of life in CD patients, it has received less attention than fibrosis occurring in other organs. A common mechanism that acts via a specific signaling pathway could underlie both intestinal fibrosis and cancer. A comprehensive overview of recently introduced biomarkers of fibrosis in CD is presented, along with a discussion of the controversial areas remaining in this field.

Emerging role of novel biomarkers in the diagnosis of inflammatory bowel disease

There is currently no gold standard test for the diagnosis of inflammatory bowel disease (IBD). Physicians must rely on a number of diagnostic tools including clinical and endoscopic evaluation as well as histologic, serologic and radiologic assessment. The real difficulty for physicians in both primary and secondary care is differentiating between patients suffering from functional symptoms and those with true underlying IBD. Alongside this, there is always concern regarding the possibility of a missed, or delayed diagnosis of ulcerative colitis (UC) or Crohn’s disease. Even once the diagnosis of IBD has been made, there is often uncertainty in distinguishing between cases of UC or Crohn’s. As a consequence, in cases of incorrect diagnosis, optimal treatment and management may be adversely affected. Endoscopic evaluation can be uncomfortable and inconvenient for patients. It carries significant risks including perforation and in terms of monetary cost, is expensive. The use of biomarkers to help in the diagnosis and differentiation of IBD has been increasing over time. However, there is not yet one biomarker, which is sensitive of specific enough to be used alone in diagnosing IBD. Current serum testing includes C-reactive protein and erythrocyte sedimentation rate, which are cheap, reliable but non-specific and thus not ideal. Stool based testing such as faecal calprotectin is a much more specific tool and is currently in widespread clinical use. Non-invasive sampling is of the greatest clinical value and with the recent advances in metabolomics, genetics and proteomics, there are now more tools available to develop sensitive and specific biomarkers to diagnose and differentiate between IBD. Many of these new advances are only in early stages of development but show great promise for future clinical use.

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.

Overcoming difficulty in diagnosis and differential diagnosis of Crohn's disease: the potential role of serological and genetic tests

Crohn's disease (CD) represents a heterogeneous group of chronic inflammatory disorders with various phenotypes. Establishing a definite diagnosis of CD should be based upon a combined assessment of clinical, endoscopic, radiological and pathological features. Although segmental disease distribution, transmural inflammation and non-caseating epithelioid granulomas have been considered as a 'hallmarks' for CD, clear diagnosis of CD in some patients has been challenging, due to overlapping endoscopic, radiographic and histologic features with other inflammatory bowel disease-like conditions. Laboratory markers (serological and genetic tests) may provide additional clues for the diagnosis and differential diagnosis of CD. This review focuses on the application of the currently available serological and genomic markers and in diagnosis and differential diagnosis of CD.

Laboratory markers in ulcerative colitis: Current insights and future advances

Ulcerative colitis (UC) and Crohn’s disease (CD) are the major forms of inflammatory bowel diseases (IBD) in man. Despite some common features, these forms can be distinguished by different genetic predisposition, risk factors and clinical, endoscopic and histological characteristics. The aetiology of both CD and UC remains unknown, but several evidences suggest that CD and perhaps UC are due to an excessive immune response directed against normal constituents of the intestinal bacterial flora. Tests sometimes invasive are routine for the diagnosis and care of patients with IBD. Diagnosis of UC is based on clinical symptoms combined with radiological and endoscopic investigations. The employment of non-invasive biomarkers is needed. These biomarkers have the potential to avoid invasive diagnostic tests that may result in discomfort and potential complications. The ability to determine the type, severity, prognosis and response to therapy of UC, using biomarkers has long been a goal of clinical researchers. We describe the biomarkers assessed in UC, with special reference to acute-phase proteins and serologic markers and thereafter, we describe the new biological markers and the biological markers could be developed in the future: (1) serum markers of acute phase response: The laboratory tests most used to measure the acute-phase proteins in clinical practice are the serum concentration of C-reactive protein and the erythrocyte sedimentation rate. Other biomarkers of inflammation in UC include platelet count, leukocyte count, and serum albumin and serum orosomucoid concentrations; (2) serologic markers/antibodies: In the last decades serological and immunologic biomarkers have been studied extensively in immunology and have been used in clinical practice to detect specific pathologies. In UC, the presence of these antibodies can aid as surrogate markers for the aberrant host immune response; and (3) future biomarkers: The development of biomarkers in UC will be very important in the future. The progress of molecular biology tools (microarrays, proteomics and nanotechnology) have revolutionised the field of the biomarker discovery. The advances in bioinformatics coupled with cross-disciplinary collaborations have greatly enhanced our ability to retrieve, characterize and analyse large amounts of data generated by the technological advances. The techniques available for biomarkers development are genomics (single nucleotide polymorphism genotyping, pharmacogenetics and gene expression analyses) and proteomics. In the future, the addition of new serological markers will add significant benefit. Correlating serologic markers with genotypes and clinical phenotypes should enhance our understanding of pathophysiology of UC.

Differential diagnosis in inflammatory bowel disease colitis: State of the art and future perspectives

Distinction between Crohn’s disease of the colon-rectum and ulcerative colitis or inflammatory bowel disease (IBD) type unclassified can be of pivotal importance for a tailored clinical management, as each entity often involves specific therapeutic strategies and prognosis. Nonetheless, no gold standard is available and the uncertainty of diagnosis may frequently lead to misclassification or repeated examinations. Hence, we have performed a literature search to address the problem of differential diagnosis in IBD colitis, revised current and emerging diagnostic tools and refined disease classification strategies. Nowadays, the differential diagnosis is an untangled issue, and the proper diagnosis cannot be reached in up to 10% of patients presenting with IBD colitis. This topic is receiving emerging attention, as medical therapies, surgical approaches and leading prognostic outcomes require more and more disease-specific strategies in IBD patients. The optimization of standard diagnostic approaches based on clinical features, biomarkers, radiology, endoscopy and histopathology appears to provide only marginal benefits. Conversely, emerging diagnostic techniques in the field of gastrointestinal endoscopy, molecular pathology, genetics, epigenetics, metabolomics and proteomics have already shown promising results. Novel advanced endoscopic imaging techniques and biomarkers can shed new light for the differential diagnosis of IBD, better reflecting diverse disease behaviors based on specific pathogenic pathways.

Systematic review: new serological markers (anti-glycan, anti-GP2, anti-GM-CSF Ab) in the prediction of IBD patient outcomes

Traditionally, IBD diagnosis is based on clinical, radiological, endoscopic, and histological criteria. Biomarkers are needed in cases of uncertain diagnosis, or to predict disease course and therapeutic response. No guideline recommends the detection of antibodies (including ASCA and ANCA) for diagnosis or prognosis of IBD to date. However, many recent data suggest the potential role of new serological markers (anti-glycan (ACCA, ALCA, AMCA, anti-L and anti-C), anti-GP2 and anti-GM-CSF Ab). This review focuses on clinical utility of these new serological markers in diagnosis, prognosis and therapeutic monitoring of IBD. Literature review of anti-glycan, anti-GP2 and anti-GM-CSF Ab and their impact on diagnosis, prognosis and prediction of therapeutic response was performed in PubMed/MEDLINE up to June 2014. Anti-glycan, anti-GP2 and anti-GM-CSF Ab are especially associated with CD and seem to be correlated with complicated disease phenotypes even if results differ between studies. Although anti-glycan Ab and anti-GP2 Ab have low sensitivity in diagnosis of IBD, they could identify a small number of CD patients not detected by other tests such as ASCA. Anti-glycan Abs are associated with a progression to a more severe disease course and a higher risk for IBD-related surgery. Anti-GP2 Ab could particularly contribute to better stratify cases of pouchitis. Anti-GM-CSF Ab seems to be correlated with disease activity and could help predict relapses. These new promising biomarkers could particularly be useful in stratification of patients according to disease phenotype and risk of complications. They could be a valuable aid in prediction of disease course and therapeutic response but more prospective studies are needed.

Family history of inflammatory bowel disease among patients with ulcerative colitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Despite numerous shared susceptibility loci between Crohn's disease and ulcerative colitis, the prevalence of family history among ulcerative colitis patients is not well-established and considered to be less prevalent. A systemic review and meta-analysis were conducted to estimate the prevalence of family history of inflammatory bowel disease in ulcerative colitis patients, and its effect on disease outcomes.

METHODS

PubMED was searched to identify studies reporting the prevalence of family history of inflammatory bowel disease among ulcerative colitis patients. Definitions of family history, study type, and subtypes of family history prevalence were abstracted, as were disease outcomes including age at ulcerative colitis diagnosis, disease location, surgery and extraintestinal manifestations. Pooled prevalence estimates were calculated using random effects models.

RESULTS

Seventy-one studies (86,824 patients) were included. The prevalence of a family history of inflammatory bowel disease in ulcerative colitis patients was 12% (95% confidence interval [CI] 11 to 13%; range 0-39%). Family history of ulcerative colitis (9%; 22 studies) was more prevalent than Crohn's disease (2%; 18 studies). Patients younger than 18years of age at time of diagnosis had a greater family history of inflammatory bowel disease (prevalence 15%, 95% CI: 11-20%; 13 studies). There were no differences in disease location, need for surgery, or extraintestinal manifestations among those with a family history, although very few studies reported on these outcomes.

CONCLUSIONS

Overall, 12% of ulcerative colitis patients have a family history of inflammatory bowel disease, and were more likely to have a family history of ulcerative colitis than Crohn's disease. Pediatric-onset ulcerative colitis patients were more likely to have a family history of inflammatory bowel disease.

Serum anti-glycan antibodies in paediatric-onset Crohn's disease: association with disease phenotype and diagnostic accuracy

Introduction

Antibodies reacting with various microbial epitopes have been described in inflammatory bowel disease (IBD) and are associated with a specific diagnosis and clinical presentation.

Aim

To evaluate the profile of new anti-glycan antibodies, their potential association with disease phenotype and diagnostic accuracy in paediatric Crohn's disease (CD).

Material and methods

Blood samples from 134 paediatric IBD patients (109 CD, 25 ulcerative colitis (UC)) and 67 controls were blindly analysed for anti-Saccharomyces cerevisiae (ASCA), anti-chitobioside carbohydrate (ACCA), anti-laminaribioside carbohydrate (ALCA), and anti-mannobioside carbohydrate (AMCA) antibodies using commercially available assays. The serological response to glycans was correlated with clinical disease characteristics.

Results

At least one of the tested anti-glycan antibodies was present in 75% of CD patients. Despite the high frequency of reactivity to glycan epitopes, a limited overlap of serological markers was observed. In total, 49% of ASCA-negative patients presented with one of the following: ACCA, ALCA, or AMCA. The occurrence of one antibody from the anti-glycan panel was independently associated with complicated disease phenotype and ileocolonic disease location. A higher level of immune response as assessed by the quartile sum scores for ACCA, ALCA, and AMCA was linked with older age at diagnosis (10–17 years) and ileocolonic disease location. The ASCA had the greatest accuracy for diagnosis and differentiation of CD.

Conclusions

Qualitative and quantitative serologicalal response to glycan epitopes was associated with distinct clinical presentation in paediatric CD patients. This raises the possibility for the use of these markers to differentiate subgroups of CD patients with more sever clinical presentation. The ASCA was the most accurate serological marker for CD; however, testing for the new anti-glycan antibodies may constitute an adjunctive tool in a specific group of patients to aid in the differentiation of CD with absent ASCA from ulcerative colitis.

New serological markers in pediatric patients with inflammatory bowel disease

The spectrum of serological markers associated with inflammatory bowel disease (IBD) is rapidly growing. Due to frequently delayed or missed diagnoses, the application of non-invasive diagnostic tests for IBD, as well as differentiation between ulcerative colitis (UC) and Crohn’s disease (CD), would be useful in the pediatric population. In addition, the combination of pancreatic autoantibodies and antibodies against Saccharomyces cerevisiae antibodies/perinuclear cytoplasmic antibody (pANCA) improved the sensitivity of serological markers in pediatric patients with CD and UC. Some studies suggested that age-associated differences in the patterns of antibodies may be present, particularly in the youngest children. In CD, most patients develop stricturing or perforating complications, and a significant number of patients undergo surgery during the disease course. Based on recent knowledge, serum antibodies are qualitatively and quantitatively associated with complicated CD behavior and CD-related surgery. Pediatric UC is characterized by extensive colitis and a high rate of colectomy. In patients with UC, high levels of anti-CBir1 and pANCA are associated with the development of pouchitis after ileal pouch-anal anastomosis. Thus, serologic markers for IBD can be applied to stratify IBD patients into more homogeneous subgroups with respect to disease progression. In conclusion, identification of patients at an increased risk of rapid disease progression is of great interest, as the application of early and more aggressive pharmaceutical intervention could have the potential to alter the natural history of IBD, and reduce complications and hospitalizations.

Increased antibody response to microbial antigens in patients with Crohn's disease and their unaffected first-degree relatives

BACKGROUND

Antibodies directed towards bacterial antigens are considered as serological markers of Crohn's disease. Their role in disease pathogenesis is still under investigation.

AIM

Assess the serologic response towards microbial antigens in Crohn's disease patients, their unaffected first-degree relatives and healthy controls.

METHODS

This retrospective study included 60 Crohn's disease patients, 86 unaffected first-degree relatives and 100 healthy controls. Their sera were tested for anti-chitobioside, anti-laminaribioside, anti-mannobioside, anti-Saccharomyces cerevisiae and anti-outer membrane porin C of Escherichia coli.

RESULTS

The prevalence of anti-chitobioside and anti-laminaribioside was higher in Crohn's disease patients and their first-degree relatives than in healthy controls (51.67%, 61.63% and 8%, respectively, for anti-chitobioside and 76.17%, 88.37% and 23.00% for anti-laminaribioside; p<0.0001). The cumulative semiquantitative immune response against all the tested antibodies was higher in unaffected relatives than in healthy controls (p<0.001). The quantitative analysis revealed that serum levels of anti-chitobioside, anti-laminaribioside and anti-mannobioside were similar in first-degree relatives and Crohn's disease patients and higher than healthy controls (p<0.001).

CONCLUSIONS

Both qualitative and quantitative analysis revealed that unaffected first-degree relatives have increased antibody response to microbial antigens. This impaired immunological response towards enteric microorganisms may result from a genetic predisposition.

Serological markers of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a heterogeneous group of chronic inflammatory disorders of the gastrointestinal tract with two main distinguishable entities, Crohn’s disease (CD) and ulcerative colitis (UC). IBD-unclassified (IBD-U) is a diagnosis that covers the “grey” zone of diagnostic uncertainty between UC and CD. Current diagnosis of IBD relies on the clinical, endoscopic, radiological, histological and biochemical features, but this approach has shortcomings especially in cases of overlapping symptoms of CD and UC. The need for a diagnostic tool that would improve the conventional methods in IBD diagnosis directed the search towards potential immunological markers, since an aberrant immune response against microbial or endogenous antigens in a genetically susceptible host seems to be implicated in IBD pathogenesis. The spectrum of antibodies to different microbial antigens and autoantibodies associated with IBD is rapidly expanding. Most of these antibodies are associated with CD like anti-glycan antibodies: anti-Saccharomices cerevisiae (ASCA) and the recently described anti-laminaribioside (ALCA), anti-chitobioside (ACCA), anti-mannobioside (AMCA), anti-laminarin (anti-L) and anti-chitin (anti-C) antibodies; in addition to other antibodies that target microbial antigens: anti-outer membrane porin C (anti-OmpC), anti-Cbir1 flagellin and anti-I2 antibody. Also, autoantibodies targeting the exocrine pancreas (PAB) were shown to be highly specific for CD. In contrast, UC has been associated with anti-neutrophil cytoplasmic autoantibodies (pANCA) and antibodies against goblet cells (GAB). Current evidence suggests that serologic panels of multiple antibodies are useful in differential diagnosis of CD versus UC and can be a valuable aid in stratifying patients according to disease phenotype and risk of complications.

Serum anti-glycan antibody biomarkers for inflammatory bowel disease diagnosis and progression: a systematic review and meta-analysis

BACKGROUND

Anti-glycan antibody serologic markers may serve as a useful adjunct in the diagnosis/prognosis of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). This meta-analysis/systemic review aimed to evaluate the diagnostic value, as well as the association of anti-glycan biomarkers with IBD susceptible gene variants, disease complications, and the need for surgery in IBD.

METHODS

The diagnostic odds ratio (DOR), 95% confidence interval (CI), and sensitivity/specificity were used to compare the diagnostic value of individual and combinations of anti-glycan markers and their association with disease course (complication and/or need for surgery).

RESULTS

Fourteen studies were included in the systemic review and nine in the meta-analysis. Individually, anti-Saccharomyces cervisiae antibodies (ASCA) had the highest DOR for differentiating IBD from healthy (DOR 21.1; 1.8-247.3; two studies), and CD from UC (DOR 10.2; CI 7.7-13.7; seven studies). For combination of ≥2 markers, the DOR was 2.8 (CI 2.2-3.6; two studies) for CD-related surgery, higher than any individual marker, while the DOR for differentiating CD from UC was 10.2 (CI 5.6-18.5; three studies) and for complication was 2.8 (CI 2.2-3.7; two studies), similar to individual markers.

CONCLUSIONS

ASCA had the highest diagnostic value among individual anti-glycan markers. While anti-chitobioside carbohydrate antibody (ACCA) had the highest association with complications, ASCA and ACCA associated equally with the need for surgery. Although in most individual studies the combination of ≥2 markers had a better diagnostic value as well as higher association with complications and need for surgery, we found the combination performing slightly better than any individual marker in our meta-analysis.

Serological antibodies in inflammatory bowel disease: a systematic review

The diagnosis of inflammatory bowel disease (IBD) is traditionally based on a combination of clinical, endoscopic, histological, and radiological criteria. However, further testing is needed in cases of diagnostic uncertainty and in predicting disease course. This systematic review focuses on the potential for 10 serological antibodies to fill these roles: pANCA, ASCA, anti-OmpC, anti-CBir1, anti-I2, ALCA, ACCA, AMCA, anti-L, and anti-C. We discuss their prevalence in IBD and health; their role in disease diagnosis and risk stratification; their stability over time; their presence in unaffected relatives; their association with genetic variants; and differences across ethnic groups. Serological antibodies have some role in primary diagnosis and in differentiating between Crohn's disease and ulcerative colitis. In indeterminate colitis, preoperative measurement of serological antibodies can help to predict the likelihood of complications among patients undergoing pouch surgery. The combined presence and magnitude of a large panel of antibodies appear to be of value in predicting disease progression. There is currently insufficient evidence to recommend the use of antibody testing to predict responses to treatment or surgery in patients with IBD.

Biomarkers in inflammatory bowel disease: current practices and recent advances

Crohn's disease and ulcerative colitis represent the two main forms of the idiopathic chronic inflammatory bowel diseases (IBD). Currently available blood and stool based biomarkers provide reproducible, quantitative tools that can complement clinical assessment to aid clinicians in IBD diagnosis and management. C-reactive protein and fecal based leukocyte markers can help the clinician distinguish IBD from noninflammatory diarrhea and assess disease activity. The ability to differentiate between forms of IBD and predict risk for disease complications is specific to serologic tests including antibodies against Saccharomyces cerevisiae and perinuclear antineutrophil cytoplasmic proteins. Advances in genomic, proteomic, and metabolomic array based technologies are facilitating the development of new biomarkers for IBD. The discovery of novel biomarkers, which can correlate with mucosal healing or predict long-term disease course has the potential to significantly improve patient care. This article reviews the uses and limitations of currently available biomarkers and highlights recent advances in IBD biomarker discovery.

Increased levels of anti-glycan antibodies in patients with cystic fibrosis

Background

The prevalence of Crohn's disease (CD) is increased in patients with cystic fibrosis (CF). Anti-Saccharomyces cerevisiae antibodies (ASCA) have been suggested as a screening tool to detect CD in CF. Recently, several new anti-glycan antibodies have been reported in CD.

Materials and methods

The sera of 119 CF patients of various age groups were prospectively screened for ASCA type IgG (gASCA), anti-laminaribioside carbohydrate IgG antibodies (ALCA), anti-chitobioside carbohydrate IgA antibodies (ACCA), and anti-mannobioside carbohydrate IgG antibodies (AMCA). The frequency of these anti-glycan antibodies was then compared in patients with CD, ulcerative colitis, rheumatoid arthritis and healthy volunteers.

Results

A significant number of CF patients were positive for gASCA (51.3% [41.6-60.6]) and up to three other anti-glycan antibodies concurrently. Serum levels of anti-glycan antibodies in CF and CD were not related to parameters of inflammation. Despite the well-documented difference in clinical course between male and female CF patients no gender difference of anti-glycan antibodies was found. In contrast, there was a significant positive correlation between anti-glycan markers and age in CF patients.

Conclusions

Our findings demonstrate for the first time the increased frequency of a panel of anti-glycan antibodies in CF and provide a link between the presence of these serological biomarkers and patient's age. Anti-glycan antibody profiling may therefore become a valuable tool in the care of patients with CF.

Progress in research of biological activity markers for inflammatory bowel disease

The incidence of inflammatory bowel disease (IBD) has been increasing in recent years. The clinical manifestations of IBD are complicated, and both intestinal and extraintestinal symptoms may develop. Due to the lack of specific index, IBD is easy to be misdiagnosed, and evaluating disease activity is more difficult. Radiology, endoscopic and histological biopsy for diagnosis are expensive. Currently, there is an urgent need of a simple, noninvasive, sensitive, economic, and highly specific method for diagnosis of IBD. Biological activity markers may meet this demand. In this paper, the clinical applicability of biological activity markers, which come from both ulcerative colitis (UC) and Crohn's disease (CD), in identifying the presence or extent of inflammatory response, is reviewed.

Predictors of fibrostenotic Crohn's disease

Intestinal fibrosis is a common and serious complication of Crohn's disease (CD) and as it can occur at any time during the disease course, it is crucial to identify patients at risk. The aim is not only to understand the pathophysiology of fibrogenesis but to be able to accurately inform subjects about their disease course, design future trials of potentially useful antifibrotic therapies, and, most important, identify those CD patients at risk, with the view to early, more aggressive medical therapy. This review summarizes the current status of our understanding and ability to predict fibrostenosing CD. The review encompasses three distinct areas: genetic variants, clinical phenotypes, and serologic markers in order to develop a conceptual framework for an understanding of fibrostenotic CD. It also aims to highlight where our knowledge is insufficient in order to identify areas that require future research.

Characterization of changes in serum anti-glycan antibodies in Crohn's disease--a longitudinal analysis

Introduction

Anti-glycan antibodies are a promising tool for differential diagnosis and disease stratification of patients with Crohn's disease (CD). We longitudinally assessed level and status changes of anti-glycan antibodies over time in individual CD patients as well as determinants of this phenomenon.

Methods

859 serum samples derived from a cohort of 253 inflammatory bowel disease (IBD) patients (207 CD, 46 ulcerative colitis (UC)) were tested for the presence of anti-laminarin (Anti-L), anti-chitin (Anti-C), anti-chitobioside (ACCA), anti-laminaribioside (ALCA), anti-mannobioside (AMCA) and anti-Saccharomyces cerevisiae (gASCA) antibodies by ELISA. All patients had at least two and up to eleven serum samples taken during the disease course.

Results

Median follow-up time for CD was 17.4 months (Interquartile range (IQR) 8.0, 31.6 months) and for UC 10.9 months (IQR 4.9, 21.0 months). In a subgroup of CD subjects marked changes in the overall immune response (quartile sum score) and levels of individual markers were observed over time. The marker status (positive versus negative) remained widely stable. Neither clinical phenotype nor NOD2 genotype was associated with the observed fluctuations. In a longitudinal analysis neither changes in disease activity nor CD behavior led to alterations in the levels of the glycan markers. The ability of the panel to discriminate CD from UC or its association with CD phenotypes remained stable during follow-up. In the serum of UC patients neither significant level nor status changes were observed.

Conclusions

While the levels of anti-glycan antibodies fluctuate in a subgroup of CD patients the antibody status is widely stable over time.

The utility of biomarkers in the diagnosis and therapy of inflammatory bowel disease

Fecal and serologic biomarkers can be used in the diagnosis and management of inflammatory bowel disease (IBD). Fecal markers such as calprotectin and lactoferrin have been studied for their ability to identify patients with IBD, assess disease activity, and predict relapse. Antibodies against Saccharomyces cerevisiae and perinuclear antineutrophil cytoplasmic proteins have been used in diagnosis of IBD, to distinguish Crohn's disease (CD) from ulcerative colitis, and to predict the risk of complications of CD. Tests for C-reactive protein and erythrocyte sedimentation rate have been used to assess inflammatory processes and predict the course of IBD progression. Levels of drug metabolites and antibodies against therapeutic agents might be measured to determine why patients do not respond to therapy and to select alternative treatments. This review addresses the potential for biomarker assays to improve treatment strategies and challenges to their use and development.

Antiglycan antibodies in Greek patients with inflammatory bowel disease

BACKGROUND

Antiglycan antibodies have recently been reported to be associated with Crohn's disease (CD). These antibodies include anti-Saccharomyces cerevisiae mannan antibodies (ASCA), anti-laminariobioside carbohydrate antibodies (ALCA), anti-chitobioside carbohydrate antibodies (ACCA), and anti-mannobioside carbohydrate antibodies (AMCA).

AIMS

The aim of this study was to evaluate their diagnostic accuracy in Greek patients with inflammatory bowel disease (IBD).

METHODS

Serum was collected from 191 patients with IBD (85 with ulcerative colitis (UC) and 106 with CD), 29 cases with other causes of intestinal inflammation and 96 healthy controls. Antiglycan antibodies were measured using commercially available enzyme immunoassays.

RESULTS

Higher levels of antiglycan antibodies were detected in patients with CD compared to patients with UC and controls. Although all types of antiglycan antibodies had a high specificity for diagnosing CD, their sensitivity was rather low, with best results obtained with ASCA and ALCA (41.5 and 52.8%, respectively). Increased levels of ASCA and ALCA were associated with stricturing and penetrating disease phenotype, and the need for surgery (p < 0.05).

CONCLUSIONS

Antiglycan antibodies in Greek IBD patients are significantly associated with CD, and especially to phenotypes of complicated disease, with ASCA and ALCA exhibiting the highest sensitivity.

Serologic antiglycan antibodies in inflammatory bowel disease

At diagnosis, the clinical presentation of both entities of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), can be highly heterogeneous, leading to a delay in correct identification or differentiation between CD and UC in a subgroup of patients. In addition, the natural history of IBD patients is strikingly variable. During the life of a CD patient, in the majority of instances, stricturing or perforating complications occur, leading to surgery. Serologic antiglycan antibodies directed against various microbial carbohydrate epitopes are useful in differentiation of CD vs. UC and are a promising tool for identification of CD patients at risk for rapid progression and need for surgical intervention. Instruments for prediction of CD behavior are critical, as the use of immunomodulators and/or biologicals early in the disease course might be justified for patients with a high hazard for complicated disease behavior.

New serological biomarkers of inflammatory bowel disease

Serological biomarkers in inflammatory bowel disease (IBD) are a rapidly expanding list of non-invasive tests for objective assessments of disease activity, early diagnosis, prognosis evaluation and surveillance. This review summarizes both old and new biomarkers in IBD, but focuses on the development and characterization of new serological biomarkers (identified since 2007). These include five new anti-glycan antibodies, anti-chitobioside IgA (ACCA), anti-laminaribioside IgG (ALCA), anti-manobioside IgG (AMCA), and antibodies against chemically synthesized (Σ) two major oligomannose epitopes, Man α-1,3 Man α-1,2 Man (ΣMan3) and Man α-1,3 Man α-1,2 Man α-1,2 Man (ΣMan4). These new biomarkers serve as valuable complementary tools to existing biomarkers not only in differentiating Crohn’s disease (CD), ulcerative colitis (UC), normal and other non-IBD gut diseases, but also in predicting disease involvement (ileum vs colon), IBD risk (as subclinical biomarkers), and disease course (risk of complication and surgery). Interestingly, the prevalence of the antiglycan antibodies, including anti-Saccharomyces cerevisiae antibodies (ASCA), ALCA and AMCA, was found to be associated with single nucleotide polymorphisms (SNPs) of IBD susceptible genes such as NOD2/CARD15, NOD1/CARD4, toll-like receptors (TLR) 2 and 4, and β-defensin-1. Furthermore, a gene dosage effect was observed: anti-glycan positivity became more frequent as the number of NOD2/CARD15 SNPS increased. Other new serum/plasma IBD biomarkers reviewed include ubiquitination factor E4A (UBE4A), CXCL16 (a chemokine), resistin, and apolipoprotein A-IV. This review also discusses the most recent studies in IBD biomarker discovery by the application of new technologies such as proteomics, fourier transform near-infrared spectroscopy, and multiplex enzyme-linked immunosorbent assay (ELISA)’s (with an emphasis on cytokine/chemokine profiling). Finally, the prospects of developing more clinically useful novel diagnostic algorithms by incorporating new technologies in serological biomarker profiling and integrating multiple biomarkers with bioinformatics analysis/modeling are also discussed.