Anti-Integrin αvβ6 Autoantibodies Are a Novel Biomarker That Antedate Ulcerative Colitis

Global evolution of inflammatory bowel disease across epidemiologic stages

During the twentieth century, inflammatory bowel disease (IBD) was considered a disease of early industrialized regions in North America, Europe and Oceania1. At the turn of the twenty-first century, IBD incidence increased in newly industrialized and emerging regions in Africa, Asia and Latin America, while the prevalence in early industrialized regions continued to grow steadily2-4. Changes in the incidence and prevalence denote the evolution of IBD across four epidemiologic stages: stage 1 (emergence), characterized by low incidence and prevalence; stage 2 (acceleration in incidence), marked by rapidly rising incidence and low prevalence; and stage 3 (compounding prevalence), where the incidence decelerates, plateaus or declines while the prevalence steadily increases. A fourth stage (prevalence equilibrium) has been proposed in which the prevalence slope plateaus due to demographic shifts in an ageing IBD population, but it has not yet been evidenced. To date, these stages have remained theoretical, lacking specific numerical indicators to define transition points. Here, using real-world data from 522 population-based studies encompassing 82 global regions and spanning more than a century (1920-2024), we show spatiotemporal transitions across stages 1-3 and model stage 4 progression. Understanding the evolution of IBD across epidemiologic stages enables healthcare systems to better anticipate the future worldwide burden of IBD.

The Power of Antibodies: Advancing Biomarker-Based Disease Detection and Surveillance

BACKGROUND

Antibodies have long served as fundamental tools in disease diagnosis and surveillance. Their utility as biomarkers has expanded beyond infectious diseases to encompass a wide range of health conditions.

OBJECTIVES

This review aims to explore recent advancements in antibody biomarker discovery and their applications in diagnosing and monitoring diverse health conditions. It also examines the role of antibody surveillance in public health and epidemiological studies.

METHODS

A comprehensive analysis of recent literature was conducted, focusing on studies that identify and characterize disease-specific antibodies. Particular attention was given to their relevance in autoimmune diseases, infections, cancers, and neurological disorders.

CONTENT

The review highlights disease-specific antibody biomarkers and their clinical significance. It also discusses the utility and challenges of antibody-based surveillance in assessing disease prevalence, tracking immunity trends, and supporting One Health strategies.

CONCLUSIONS

Recent advancements in antibody biomarker discovery demonstrate significant potential in improving early diagnosis, personalized treatment, and population-level health management. Antibody surveillance continues to play a pivotal role in guiding public health responses and understanding disease dynamics.

Autoimmunity in inflammatory bowel disease: a holobiont perspective

Adaptive immunity towards self-antigens (autoimmunity) and intestinal commensal microbiota is a key feature of inflammatory bowel disease (IBD). Considering mucosal adaptive immunity from a holobiont perspective, where the host and its microbiome form a single physiological unit, emphasises the challenge of avoiding damaging responses to self-antigen and symbiotic microbial communities in the gut while protecting against potential pathogens. Intestinal tolerance mechanisms prevent maladaptive T and B cell responses to microbial, environmental, and self-antigens, which drive inflammation. We discuss the spectrum of antimicrobial and autoantibody responses and highlight mechanisms by which common IBD-associated adaptive immune responses contribute to disease.

Environmental risk factors of inflammatory bowel disease: toward a strategy of preventative health

The pathogenesis of inflammatory bowel disease (IBD) involves a complex interplay between genetic, environmental, and microbial factors. Many of these environmental determinants are modifiable, offering opportunities to prevent disease or delay its onset. Advances in the study of preclinical IBD cohorts offer the potential to identify biomarkers that predict individuals at high risk of developing IBD, enabling targeted environmental interventions aimed at reducing IBD incidence. This review summarizes findings from 79 meta-analyses on modifiable environmental factors associated with the development of IBD. Identified risk factors include smoking, Western diets, ultra-processed foods, and early life antibiotic use, while protective factors include breastfeeding, Mediterranean diets rich in fiber, plant-based foods, and fish, along with an active physical lifestyle. Despite the promise shown by observational data, interventional or randomized controlled studies evaluating the efficacy of modifying environmental risk factors remain limited and mostly focus on dietary intervention. This review aims to inform the design of higher quality interventional and randomized controlled studies for disease prevention while providing actionable guidance to healthcare providers on reducing the risk of developing IBD through environmental modifications.

Preclinical Protein Signatures of Crohn's Disease and Ulcerative Colitis: A Nested Case-Control Study Within Large Population-Based Cohorts

BACKGROUND & AIMS

Biomarkers are needed to identify individuals at elevated risk of inflammatory bowel disease. This study aimed to identify protein signatures predictive of inflammatory bowel disease.

METHODS

Using large population-based cohorts (n ≥180,000), blood samples were obtained from individuals who later in life were diagnosed with inflammatory bowel disease and compared with age and sex-matched controls, free from inflammatory bowel disease during follow-up. A total of 178 proteins were measured on Olink platforms. We used machine-learning methods to identify protein signatures of preclinical disease in the discovery cohort (n = 312). Their performance was validated in an external preclinical cohort (n = 222) and assessed in an inception cohort (n = 144) and a preclinical twin cohort (n = 102).

RESULTS

In the discovery cohort, a signature of 29 proteins differentiated preclinical Crohn's disease (CD) cases from controls, with an area under the curve (AUC) of 0.85. Its performance was confirmed in the preclinical validation (AUC = 0.87) and the inception cohort (AUC = 1.0). In preclinical samples, downregulated (but not upregulated) proteins related to gut barrier integrity and macrophage functionality correlated with time to diagnosis of CD. The preclinical ulcerative colitis signature had a significant, albeit lower, predictive ability in the discovery (AUC = 0.77), validation (AUC = 0.67), and inception cohorts (AUC = 0.95). The preclinical signature for CD demonstrated an AUC of 0.89 when comparing twins with preclinical CD with matched external healthy twins, but its predictive ability was lower (AUC = 0.58; P = .04) when comparing them with their healthy twin siblings, that is, when accounting for genetic and shared environmental factors.

CONCLUSION

We identified protein signatures for predicting a future diagnosis of CD and ulcerative colitis, validated across independent cohorts. In the context of CD, the signature offers potential for early prediction.

Anti-integrin αvβ6 Antibodies Predict Pouchitis in Patients With Ulcerative Colitis After Restorative Proctocolectomy With Ileal Pouch-Anal Anastomosis

BACKGROUND

Pouchitis is the most common complication of restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC). We previously reported the presence of anti-integrin αvβ6 antibodies in the serum of patients with UC. This study investigated the association between anti-integrin αvβ6 antibodies and the development of pouchitis in patients with UC.

METHODS

Serum levels of anti-integrin αvβ6 antibodies were measured by enzyme-linked immunosorbent assay in 16 patients with UC who underwent RPC with IPAA. Integrin αvβ6 expression in the colonic, terminal ileal, and pouch epithelium was examined using immunohistochemistry and western blot analysis.

RESULTS

Anti-integrin αvβ6 antibody levels in patients with UC were significantly decreased at 3, 9, and 12 months after RPC (P < .05). However, in patients who developed pouchitis, antibody levels remained high. The antibody levels at the time of RPC were significantly higher in patients who developed pouchitis compared to those who did not. Kaplan-Meier analysis revealed a significantly higher incidence of pouchitis in patients with antibody levels above the cutoff at the time of RPC. Although integrin αvβ6 was not expressed in the terminal ileal epithelium at the time of RPC, expression became positive in the pouch epithelium of patients with pouchitis.

CONCLUSIONS

The anti-integrin αvβ6 antibody levels in patients with UC were decreased after RPC but remained high in patients who developed pouchitis. The antibody levels at the time of RPC may serve as a potential prognostic biomarker for predicting the risk of pouchitis in patients with UC.

Serum Collagen Biomarkers Are Reflective of Tissue Specific Fibroblasts Associated With Ulcerative Colitis Activity and Treatment Response to Ustekinumab

BACKGROUND

There is a need to identify peripheral biomarkers reflective of defined disease associated fibroblasts in Ulcerative Colitis (UC), with the aim of enabling clinical development approaches for novel-stromal-targeted therapeutics for individuals at risk for fibrostenotic complications. Additionally, longitudinal non-invasive biomarkers of tissue remodelling, fibroblast biology and pharmacodynamic measurements are needed in the clinic to facilitate risk stratification.

AIM

To identify novel blood protein biomarkers associated with defined fibroblast subsets, tissue remodelling and treatment response/non-response in UC.

METHODS

We performed data analysis on matched serum and tissue transcriptomics from the UNIFI trial at weeks 0 and 8 in clinical responders and non-responders. Detailed gene correlation analysis was performed on 97 colonic biopsies from 50 patients pre- and post-treatment, to construct detailed cell-type mapping associated with clinical parameters. Detailed serum-based proteomics analysis was performed using matched serum and tissue sample sets to evaluate specific correlations between defined tissue cellular subsets and unique peripheral proteins, reflective of defined tissue transcriptional subsets and clinical parameters.

RESULTS

Evaluation of the UNIFI clinical study, revealed a significant association between intestinal-inflammatory activated fibroblasts (IIAF) and various clinical parameters, including Geboes scores. These findings were unique to IIAFs and were confirmed using spatial tissue transcriptomics. Evaluation of novel peripheral proteomics revealed a significant correlation between selective serum collagen biomarkers, including Pro-Collagen 22, Collagen 1M, CTX-III, ELP-3, and the IIAF tissue module. These serum collagen biomarkers were unique to IIAFs, as other broad proteomics methodologies failed to demonstrate significant correlations with known UC serum markers. Ustekinumab endoscopic responders had a significant decrease in IIAFs, which was associated with decreases in these IIAF associated serum proteins. Furthermore, C1M and ELP-3 demonstrated predictive value to enable characterisation of UC patients with IIAF driven disease.

CONCLUSIONS

These serum biomarkers were correlated with tissue levels of IIAFs, identifying unique peripheral markers of tissue associated cell types correlated with fibrosis. Given the association of IIAFs and treatment response, this highlights the utility of these triaged collagen biomarkers for anti-stromal therapeutic development and patient stratification in UC and beyond.

Onset of pouchitis after colectomy for ulcerative colitis: reducing the risk

INTRODUCTION

Pouchitis remains the most common complication after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (IPAA). Despite the burden of pouchitis, our ability to recognize the patients at greatest risk for pouchitis and to offer early intervention for the prevention or early treatment is limited.

AREAS COVERED

In this review, we will discuss the diagnostic categories of pouchitis, as well as the common approaches to treatment. We will then discuss gaps in research and clinical care. These include opportunities to improve our understanding of the risk factors associated with the development of pouchitis as well as the role that primary and secondary prevention may play in the management of patients after IPAA to prevent pouchitis. We will then discuss future research goals to decrease the burden of pouchitis.

EXPERT OPINION

Although the burden of pouchitis is well recognized, we have an opportunity to improve our methods of risk stratification to offer early intervention to those patients at the greatest risk for developing pouchitis. Understanding which preventive therapies, in which populations, and under which treatment settings offer the most benefit will be critical issues to address in the near future to improve care of patients after IPAA for UC.

Integrin αVβ6: Autoantigen and Driver of Epithelial Remodeling in Colon and Bile Ducts in Primary Sclerosing Cholangitis and Inflammatory Bowel Disease

BACKGROUND

Recently, autoantibodies directed against the epithelial adhesion protein integrin αVβ6 have been identified that are strongly associated with ulcerative colitis (UC). We aimed to elucidate whether anti-integrin αVβ6 (anti-αVβ6) is present in primary sclerosing cholangitis (PSC), its associated inflammatory bowel disease, or other cholestatic liver diseases and their persistence after proctocolectomy.

METHODS

We detected anti-αVβ6 by an enzyme-linked immunosorbent assay in sera collected at 2 German tertiary centers, including healthy controls (N = 62), UC (N = 36), Crohn's disease (CD, N = 65), PSC-inflammatory bowel diseases (IBD) (78 samples from N = 41 patients), PSC without IBD (PSC, 41 samples from N = 18 patients), primary biliary cholangitis (PBC, N = 24), autoimmune hepatitis (AIH, N = 32), secondary sclerosing cholangitis (SSC, N = 12), and metabolic dysfunction-associated steatotic liver disease (MASLD, N = 24). In addition, sera after proctocolectomy were studied (44 samples/N = 10 patients). Immunofluorescent analyses were performed in tissue samples from liver, large bile duct from surgical resections, and colon of PSC patients.

RESULTS

Anti-αVβ6 occurred in 91% of UC, 17% of CD, 73% of PSC-IBD, 39% of PSC, 4% of PBC, 14% of AIH, and 0% of healthy controls, SSC, or MASLD. Integrin αVβ6 is selectively expressed in disease-associated epithelia of both bile duct and colon. Anti-αVβ6 levels correlate moderately with intestinal disease activity in PSC-IBD, but only weakly with biliary disease.

CONCLUSIONS

Anti-αVβ6 frequently occurs in patients suffering from PSC, especially in PSC-IBD. Anti-αVβ6 levels positively correlate to IBD activity in PSC-IBD, but may also occur in the absence of clinically manifest IBD in PSC.

[Update on the pathophysiology, prediction and prevention of inflammatory bowel diseases]

BACKGROUND

The pathophysiology of inflammatory bowel diseases is not fully understood. In a staged model by the European Crohn's and Colitis Organization (ECCO) regarding disease development, it is assumed that there is a population at risk for manifestation of disease following subtle changes over time.

OBJECTIVE

This work aims to summarize the current state of knowledge regarding the pathophysiology, prediction and prevention of chronic inflammatory bowel diseases.

MATERIALS AND METHODS

Selective literature research via PubMed.

RESULTS

Several genetic, biochemical, and microbiome scores have the potential to identify individuals at increased risk of developing inflammatory bowel disease, possibly up to a decade before onset.

DISCUSSION

The growing knowledge regarding the pathogenesis of inflammatory bowel diseases makes prediction before disease onset a possible future diagnostic goal. Hypothetically, early changes before the disease manifests could be reversible and may be amenable to prevention programs.

Early subclinical stages of the inflammatory bowel diseases: insights from human and animal studies

The inflammatory bowel diseases (IBD) occur in genetically susceptible individuals that mount inappropriate immune responses to their microbiota leading to chronic intestinal inflammation. The natural history of IBD progression begins with early subclinical stages of disease that occur before clinical diagnosis. Improved understanding of those early subclinical stages could lead to new or improved strategies for IBD diagnosis, prognostication, or prevention. Here, we review our current understanding of the early subclinical stages of IBD in humans including studies from first-degree relatives of patients with IBD and members of the general population who go on to develop IBD. We also discuss representative mouse models of IBD that can be used to investigate disease dynamics and host-microbiota relationships during these early stages. In particular, we underscore how mouse models of IBD that develop disease later in life with variable penetrance may present valuable opportunities to discern early subclinical mechanisms of disease before histological inflammation and other severe symptoms become apparent.

Anti-integrin αvβ6 antibody as a biomarker for diagnosing ulcerative colitis: a nationwide multicenter validation study

BACKGROUND

A serum biomarker for diagnosing ulcerative colitis (UC) remains to be established. Although we recently reported an anti-integrin αvβ6 antibody (V6 Ab) for diagnosing UC with high sensitivity and specificity, no large-scale validation study exists. This study aimed to validate the diagnostic value of V6 Ab for UC using a nationwide multicenter cohort study.

METHODS

We measured V6 Ab titers in patients definitively diagnosed with UC, Crohn's disease (CD), or other gastrointestinal disorders (OGDs). The primary outcome was the diagnostic value of V6 Ab. Secondary outcomes were factors associated with false-negative results in patients with UC and false-positive results in patients without UC and the heterogeneity of the diagnostic value of V6 Ab among the participating facilities.

RESULTS

We enrolled 1241, 796, and 206 patients with UC, CD, and OGD, respectively, from 28 Japanese high-volume referral centers. The diagnostic sensitivity of V6 Ab for UC was 87.7%, and its specificities for CD and OGDs were 82.0% and 87.4%, respectively. Multivariable logistic regression analysis showed that false-negative results were associated with older age at the time of sample collection, current smokers, lower partial Mayo score, and not receiving advanced therapies in patients with UC, and false-positive results were associated with colonic CD in patients with CD. No factor was associated with false-positive results in patients with OGDs. There were no significant differences in the diagnostic value of V6 Ab among the centers.

CONCLUSIONS

The diagnostic value of V6 Ab for UC was validated in the large-scale nationwide multicenter study.

Human ITGAV variants are associated with immune dysregulation, brain abnormalities, and colitis

Integrin heterodimers containing an Integrin alpha V subunit are essential for development and play critical roles in cell adhesion and signaling. We identified biallelic variants in the gene coding for Integrin alpha V (ITGAV) in three independent families (two patients and four fetuses) that either caused abnormal mRNA and the loss of functional protein or caused mistargeting of the integrin. This led to eye and brain abnormalities, inflammatory bowel disease, immune dysregulation, and other developmental issues. Mechanistically, the reduction of functional Integrin αV resulted in the dysregulation of several pathways including TGF-β-dependent signaling and αVβ3-regulated immune signaling. These effects were confirmed using immunostaining, RNA sequencing, and functional studies in patient-derived cells. The genetic deletion of itgav in zebrafish recapitulated patient phenotypes including retinal and brain defects and the loss of microglia in early development as well as colitis in juvenile zebrafish with reduced SMAD3 expression and transcriptional regulation. Taken together, the ITGAV variants identified in this report caused a previously unknown human disease characterized by brain and developmental defects in the case of complete loss-of-function and atopy, neurodevelopmental defects, and colitis in cases of incomplete loss-of-function.

Review article: Prevention of inflammatory bowel disease-The path forward

BACKGROUND

The possibility of preventing inflammatory bowel disease (IBD) is becoming more plausible due to advances in understanding preclinical disease and successful prevention trials in other immune-mediated diseases, such as type 1 diabetes and rheumatoid arthritis. However, before that possibility becomes reality, several efforts need to occur in parallel and in a coordinated way.

AIM

To propose some critical steps necessary for advancing the field of IBD prediction and prevention.

METHODS

We reviewed the current literature to identify the necessary steps toward a preventive strategy for IBD.

RESULTS

The first step should determine the most robust predictive biomarkers and validate them across independent cohorts, creating a multidimensional predictive tool. The second step is to gain a better understanding of the preferences of first-degree relatives and people at risk for IBD, informing the implementation of screening and preventive strategies. Third, these efforts should contribute to the development of high-risk clinics and establish the necessary networks for disease prevention trials.

CONCLUSIONS

Advancing the field of IBD prediction and prevention will require a multifaceted approach, integrating biomarker discovery, understanding patient preferences, and establishing infrastructure for a collaborative network to support the practical implementation of IBD prevention strategies.

Review article: Measuring disease severity in inflammatory bowel disease - Beyond treat to target

BACKGROUND

Inflammatory bowel disease (IBD) follows a heterogenous disease course and predicting a patient's prognosis is challenging. There is a wide burden of illness in IBD and existing tools measure disease activity at a snapshot in time. Comprehensive assessment of IBD severity should incorporate disease activity, prognosis, and the impacts of disease on a patient. This review investigates the concept of disease severity in adults with IBD to highlight key components contributing to this.

METHODS

To perform this narrative review, a Medline search was conducted for full-text articles available at 1st March 2024 using search terms which encompassed disease activity assessment, disease severity, prognosis, natural history of Crohn's disease (CD) and ulcerative colitis (UC), and the burden of IBD.

RESULTS

Current methods of disease assessment in IBD have evolved from a focus on the burden of symptoms to one that includes inflammatory targets, genetic, serological, and proteomic profiles, and assessments of quality-of-life (QoL), disability, and psychosocial health. Longitudinal studies of IBD suggest that the burden of illness is driven by disease phenotype, clinical markers of complicated disease course (previous intestinal resection, corticosteroid use, perianal disease in CD, recent hospitalisations in UC), gut inflammation, and the impact of IBD on the patient.

CONCLUSIONS

Disease severity in IBD can be difficult to conceptualise due to the multitude of factors that contribute to IBD outcomes. Measurement of IBD severity may better encapsulate the full burden of illness rather than gut inflammation alone at a single timepoint and may be associated with longitudinal outcomes.

Anti-integrin αvβ6 Autoantibodies are Increased in Primary Sclerosing Cholangitis Patients With Concomitant Inflammatory Bowel Disease and Correlate With Liver Disease Severity

BACKGROUND & AIMS

Anti-integrin αvβ6 autoantibodies (anti-αvβ6) are found in more than 50% of individuals with ulcerative colitis (UC). We aimed to determine the prevalence of anti-αvβ6 in patients with primary sclerosing cholangitis (PSC) and their association with liver disease severity.

METHODS

Four cohorts of pre-liver transplant patients with PSC were recruited. Patients with inflammatory bowel disease (IBD) and healthy controls (HCs) served as comparators. Total IgG and anti-αvβ6 levels were measured using enzyme-linked immunosorbent assay. Olink inflammation panel was run on a subset of samples. Multivariable linear regression analysis was performed to assess the association between anti-αvβ6 and indices of liver disease severity.

RESULTS

A total of 137 patients with PSC (including 76 with PSC-UC, 33 with PSC-Crohn's disease (CD), and 28 with PSC alone) and 160 controls (including 91 with IBD and 69 HCs) were enrolled. Anti-αvβ6 levels were significantly higher in PSC-UC and PSC-CD compared with PSC alone (P < .0001 and P < .003) and HCs (P < .0001 and P < .0001). However, anti-αvβ6 levels in PSC alone were not increased compared with HCs. In patients with PSC-IBD, anti-αvβ6 levels correlated with markers of liver disease severity, including alkaline phosphatase level (r = 0.32; P = .004), the revised Mayo PSC risk score (r = 0.25; P = .02), and liver stiffness measurement (r = 0.43; P = .008) after adjusting for age, gender, race/ethnicity, and IBD subtype. Additionally, anti-αvβ6 levels were associated with markers of systemic inflammation and tissue remodeling.

CONCLUSION

Anti-αvβ6 autoantibodies identify a subset of patients with PSC with concomitant IBD.

Ulcerative colitis: clinical biomarkers, therapeutic targets, and emerging treatments

Ulcerative colitis (UC) is one of the two forms of inflammatory bowel disease. It affects 5 million people globally, and is a chronic and recurring inflammation of the gastrointestinal tract with clinical presentation of abdominal pain, chronic diarrhea, rectal bleeding, and weight loss. The cause and the etiology of UC remain poorly understood. There is no cure and no 'gold standard diagnostic' for UC. The existing treatments are ineffective, and UC patients have a lower life expectancy with a risk of colorectal cancer. Recent studies in pathophysiology, clinical presentation, and biomarkers have significantly improved our understanding of UC. In this review we summarize recent advances in identifying novel clinical biomarkers, diagnostics, treatment targets, and emerging therapeutics. These insights are expected to assist in developing effective treatments for UC.

Neutralizing Autoantibodies against Interleukin-10 in Inflammatory Bowel Disease

We discovered high-titer neutralizing autoantibodies against interleukin-10 in a child with infantile-onset inflammatory bowel disease (IBD), a phenocopy of inborn errors of interleukin-10 signaling. After B-cell-depletion therapy and an associated decrease in the anti-interleukin-10 titer, conventional IBD therapy could be withdrawn. A second child with neutralizing anti-interleukin-10 autoantibodies had a milder course of IBD and has been treated without B-cell depletion. We conclude that neutralizing anti-interleukin-10 autoantibodies may be a causative or modifying factor in IBD, with potential implications for therapy. (Funded by the National Institute for Health and Care Research and others.).

Precision Medicine in Inflammatory Bowel Disease: A Spotlight on Emerging Molecular Biomarkers

Inflammatory bowel diseases (IBD) remain challenging in terms of understanding their causes and in terms of diagnosing, treating, and monitoring patients. Modern diagnosis combines biomarkers, imaging, and endoscopic methods. Common biomarkers like CRP and fecal calprotectin, while invaluable tools, have limitations and are not entirely specific to IBD. The limitations of existing markers and the invasiveness of endoscopic procedures highlight the need to discover and implement new markers. With an ideal biomarker, we could predict the risk of disease development, as well as the possibility of response to a particular therapy, which would be significant in elucidating the pathogenesis of the disease. Recent research in the fields of machine learning, proteomics, epigenetics, and gut microbiota provides further insight into the pathogenesis of the disease and is also revealing new biomarkers. New markers, such as BAFF, PGE-MUM, oncostatin M, microRNA panels, αvβ6 antibody, and S100A12 from stool, are increasingly being identified, with αvβ6 antibody and oncostatin M being potentially close to being presented into clinical practice. However, the specificity of certain markers still remains problematic. Furthermore, the use of expensive and less accessible technology for detecting new markers, such as microRNAs, represents a limitation for widespread use in clinical practice. Nevertheless, the need for non-invasive, comprehensive markers is becoming increasingly important regarding the complexity of treatment and overall management of IBD.

Diagnostic Procedures for Inflammatory Bowel Disease: Laboratory, Endoscopy, Pathology, Imaging, and Beyond

Diagnosing inflammatory bowel disease (IBD) can often be challenging, and differentiating between Crohn's disease and ulcerative colitis can be particularly difficult. Diagnostic procedures for IBD include laboratory tests, endoscopy, pathological tests, and imaging tests. Serological and stool tests can be easily performed in an outpatient setting and provide critical diagnostic clues. Although endoscopy is an invasive procedure, it offers essential diagnostic information and allows for tissue biopsy and therapeutic procedures. Video capsule endoscopy and device-assisted enteroscopy are endoscopic procedures used to evaluate the small bowel. In addition to endoscopy, magnetic resonance imaging, computed tomography, and ultrasound (US) are valuable tools for small bowel assessment. Among these, US is noninvasive and easily utilized, making its use highly practical in daily clinical practice. Endoscopic biopsy aids in the diagnosis of IBD and is crucial for assessing the histological activity of the disease, facilitating a thorough evaluation of disease remission, and aiding in the development of treatment strategies. Recent advances in artificial intelligence hold promise for enhancing various aspects of IBD management, including diagnosis, monitoring, and precision medicine. This review compiles current procedures and promising future tools for the diagnosis of IBD, providing comprehensive insights.

Transmural cross-sectional findings and bowel damage assessment in preclinical Crohn's disease: a case-control study

PURPOSE

Crohn's disease (CD) is a progressive disorder leading to cumulative bowel damage. The Lémann index is a validated tool that can help in monitoring the progression of the disease and evaluating the effectiveness of different therapies. Our aim was to describe the main radiological findings in incidentally diagnosed CD and to evaluate bowel damage in this subgroup compared to patients diagnosed at later stages.

METHODS

Patients with an incidental diagnosis of CD during the colorectal cancer screening program were compared to controls with a CD cohort diagnosed after symptomatic onset and matched 1:1 by disease extent. All cross-sectional examinations were centrally read, performing a descriptive analysis of the main findings and calculation of Lémann index.

RESULTS

Thirty-eight patients were included: 19 with preclinical CD (median age 55 years (IQR, 54-62), 53% male, 74% non-smokers; 74% B1 and 26% B2) and 19 matched-controls with symptomatic CD. In those with preclinical CD, the most frequent transmural findings on MRE were contrast enhancement (79%), wall thickening (79%), followed by lymphadenopathy (68%), edema (42%), and increased vascularity (42%). Among those with strictures, controls showed a higher rate of preestenotic dilation (100% vs. 0%, p = 0.01). Bowel damage assessment revealed no statistically significant differences in the Lémann index between preclinical CD and controls (p = 0.95). A statistically significant higher score in the colonic/rectum score was observed (p = 0.014).

CONCLUSION

Patients with preclinical CD demonstrate similar radiological findings and degree of bowel damage as new-onset symptomatic CD.

Challenges in IBD Research 2024: Novel Technologies

Novel technology is one of the five focus areas of the Challenges in Inflammatory Bowel Disease (IBD) Research 2024 document. Building off the Challenges in IBD Research 2019 document, the Foundation aims to provide a comprehensive overview of current gaps in IBD research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in interception, remission, and restoration for these diseases. The document is the result of a multidisciplinary collaboration from scientists, clinicians, patients, and funders and represents a valuable resource for patient-centric research prioritization. Specifically, the Novel Technologies section focuses on addressing key research gaps to enable interception and improve remission rates in IBD. This includes testing predictions of disease onset and progression, developing novel technologies tailored to specific phenotypes, and facilitating collaborative translation of science into diagnostics, devices, and therapeutics. Proposed priority actions outlined in the document include real-time measurement of biological changes preceding disease onset, more effective quantification of fibrosis, exploration of technologies for local treatment of fistulas, and the development of drug delivery platforms for precise, location-restricted therapies. Additionally, there is a strong emphasis on fostering collaboration between various stakeholders to accelerate progress in IBD research and treatment. Addressing these research gaps necessitates the exploration and implementation of bio-engineered novel technologies spanning a spectrum from materials to systems. By harnessing innovative ideas and technologies, there's a collective effort to enhance patient care and outcomes for individuals affected by IBD.

Challenges in IBD Research 2024: Precision Medicine

Precision medicine is part of 5 focus areas of the Challenges in IBD Research 2024 research document, which also includes preclinical human IBD mechanisms, environmental triggers, novel technologies, and pragmatic clinical research. Building on Challenges in IBD Research 2019, the current Challenges aims to provide a comprehensive overview of current gaps in inflammatory bowel diseases (IBDs) research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in interception, remission, and restoration for these diseases. The document is the result of multidisciplinary input from scientists, clinicians, patients, and funders, and represents a valuable resource for patient-centric research prioritization. In particular, the precision medicine section is focused on the main research gaps in elucidating how to bring the best care to the individual patient in IBD. Research gaps were identified in biomarker discovery and validation for predicting disease progression and choosing the most appropriate treatment for each patient. Other gaps were identified in making the best use of existing patient biosamples and clinical data, developing new technologies to analyze large datasets, and overcoming regulatory and payer hurdles to enable clinical use of biomarkers. To address these gaps, the Workgroup suggests focusing on thoroughly validating existing candidate biomarkers, using best-in-class data generation and analysis tools, and establishing cross-disciplinary teams to tackle regulatory hurdles as early as possible. Altogether, the precision medicine group recognizes the importance of bringing basic scientific biomarker discovery and translating it into the clinic to help improve the lives of IBD patients.

Proteomic Differences in Colonic Epithelial Cells in Ulcerative Colitis Have an Epigenetic Basis

Background and Aims

The colonic epithelium serves as both a barrier to lumenal contents and a gatekeeper of inflammatory responses. In ulcerative colitis (UC), epithelial dysfunction is a core feature, but little is known about the cellular changes that may underlie disease pathology. We therefore evaluated how the chromatin epigenetics and proteome of epithelial cells differs between health and UC.

Methods

We sorted live CD326+ epithelial cells from colon biopsies of healthy control (HC) screening colonoscopy recipients and from inflamed or uninflamed colon segments of UC patients on no biologic nor immunomodulator therapy (n = 5-7 subjects per group). Cell lysates were analyzed by proteomic evaluation and nuclei were analyzed for open chromatin with assay for transposase-accessible chromatin using sequencing.

Results

Proteins most highly elevated in inflamed UC biopsies relative to HC were those encoded by the HLA-DRA (P = 3.1 × 10-33) and CD74 (P = 1.6 × 10-27), genes associated with antigen presentation, and the antimicrobial dual oxidase 2 (DUOX2) (P = 3.2 × 10-28) and lipocalin-2 (P = 2.2 × 10-26) genes. Conversely, the water channel aquaporin 8 was strikingly less common with inflammation (P = 1.9 × 10-18). Assay for transposase-accessible chromatin using sequencing revealed more open chromatin around the aquaporin 8 gene in HCs (P = 2.0 × 10-2) and more around the DUOX2/DUOXA2 locus in inflamed UC colon (P = 5.7 × 10-4), suggesting an epigenetic basis for differential protein expression by epithelial cells in health and disease.

Conclusion

Numerous differences exist between the proteome and chromatin of colonic epithelial cells in UC patients and HCs, some of which correlate to suggest specific epigenetic mechanisms regulating the epithelial proteome.

The diagnostic performance of serum αvβ6 autoantibodies for ulcerative colitis: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Currently, there is no single golden standard for diagnosing ulcerative colitis (UC). Now serum αvβ6 autoantibodies have shown promise as a diagnostic tool for UC. Here the aim was to determine the diagnostic performance of serum αvβ6 autoantibodies for UC.

METHODS

PubMed, the Cochrane Library, the Embase, and the Web of Science were searched comprehensively. STATA software was utilized to analyze the relevant data.

RESULTS

9 studies from 6 articles with 1827 subjects were eligible. The summary sensitivity and specificity of serum αvβ6 autoantibodies to diagnose UC were 0.82 (95 % confidence interval (CI): 0.65-0.92) and 0.94 (95 % CI: 0.90-0.97) with an area under the summary receiver operating characteristic curve of 0.96 (95 % CI: 0.94-0.97). Subgroup analysis was conducted owning to substantial heterogeneity between studies (I2 = 97 % and P < 0.001). The aggregate sensitivity and specificity to diagnose UC in adults were 0.75 (95 % CI: 0.61-0.86) and 0.95 (95 % CI: 0.90-0.97), and when using a threshold of mean control+3SD, 0.80 (95 % CI: 0.60-0.91) and 0.96 (95 % CI: 0.90-0.99), respectively. Additionally, to differentiate UC from healthy participants, non-inflammatory bowel disease, and Crohn's disease, the overall specificity was 0.96, 0.88, and 0.80, respectively.

CONCLUSIONS

serum αvβ6 autoantibodies, as a non-invasive tool, demonstrated good diagnostic accuracy for UC. However, their application may be limited in some immune-related disorders, and further studies are needed for validation.

Post-hospitalization Short Versus Long Steroid Taper Strategies in Patients With Acute Severe Ulcerative Colitis: A Comparison of Clinical Outcomes

Background

Ulcerative colitis (UC) is a chronic inflammatory colon disease characterized by relapsing flares and remission episodes. However, the optimal steroid tapering strategy in patients hospitalized for acute severe UC (ASUC) remains relatively unknown. We aim to examine the clinical outcomes in patients hospitalized for ASUC regarding variable prednisone taper regimens upon discharge.

Methods

We retrospectively reviewed all adult patients admitted to our facility with ASUC between 2000 and 2022. Patients were divided into 2 groups based on the duration of steroid taper on discharge (< 6 and > 6 weeks). Patients who had colectomy at index admission were excluded from the analysis. The primary outcome was rehospitalization for ASUC within 6 months of index admission. Secondary outcomes included the need for colectomy, worsening endoscopic disease extent and/or severity during the follow-up period (6 months), and a composite outcome as a surrogate of worsening disease (defined as a combination of all products above). Two-sample t-tests and Pearson's chi-square tests were used to compare the means of continuous and categorical variables, respectively. Multivariate logistic regression analysis was performed to identify independent predictors for rehospitalization with ASUC.

Results

A total of 215 patients (short steroid taper = 91 and long steroid taper = 124) were analyzed. A higher number of patients in the long steroid taper group had a longer disease duration since diagnosis and moderate-severe endoscopic disease activity (63.8 vs. 25.6 months, p < 0.0001, 46.8% vs. 23.1%, P = ≤ .05, respectively). Both groups had similar disease extent, prior biologic therapy, and the need for inpatient rescue therapy. At the 6-month follow-up, rates of rehospitalization with a flare of UC were comparable between the 2 groups (68.3% vs. 68.5%, P = .723). On univariate and multivariate logistic regression, escalation of steroid dose within four weeks of discharge (aOR 6.09, 95% CI: 1.82-20.3, P  = .003) was noted to be the only independent predictor for rehospitalization with ASUC.

Conclusions

This is the first study comparing clinical outcomes between post-discharge steroid tapering regimens in hospitalized patients for ASUC. Both examined steroid taper regimens upon discharge showed comparable clinical results. Hence, we suggest a short steroid taper as a standard post-hospitalization strategy in patients following ASUC encounters. It is likely to enhance patient tolerability and reduce steroid-related adverse effects without adversely affecting outcomes.

High-throughput omics technologies in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing intestinal disease. Elucidation of the pathogenic mechanisms of IBD requires high-throughput technologies (HTTs) to effectively obtain and analyze large amounts of data. Recently, HTTs have been widely used in IBD, including genomics, transcriptomics, proteomics, microbiomics, metabolomics and single-cell sequencing. When combined with endoscopy, the application of these technologies can provide an in-depth understanding on the alterations of intestinal microbe diversity and abundance, the abnormalities of signaling pathway-mediated immune responses and functionality, and the evaluation of therapeutic effects, improving the accuracy of early diagnosis and treatment of IBD. This review comprehensively summarizes the development and advancement of HTTs, and also highlights the challenges and future directions of these technologies in IBD research. Although HTTs have made striking breakthrough in IBD, more standardized methods and large-scale dataset processing are still needed to achieve the goal of personalized medicine.

Integrins in biliary injury and fibrosis

PURPOSE OF REVIEW

Current treatment options for cholangiopathies are severely limited and there is thus a critical need to identify and develop therapies. This review discusses the role of integrins in biliary injury and fibrosis and their potential as therapeutic targets.

RECENT FINDINGS

There are a diverse set of roles that integrins play in biliary injury and fibrosis. Some integrins activate TGF-β signaling or are involved in sensing of the extracellular matrix, making them attractive targets for biliary fibrosis. In recent work, autoantibodies to α v β 6 were identified in patients with PSC, supporting the relevance of this integrin in the disease. In addition, a role for α 2 β 1 in cyst formation was identified in a mouse model of polycystic liver disease. Leukocyte integrins (e.g. α E β 7 and α 4 β 7 ) contribute to lymphocyte trafficking, making them potential targets for biliary inflammation; however, this has not yet translated to the clinic.

SUMMARY

While all members of the same family of proteins, integrins have diverse roles in the pathogenesis of biliary disease. Targeting one or multiple of these integrins may slow or halt the progression of biliary injury and fibrosis by simultaneously impacting different pathologic cells and processes.

Deciphering the different phases of preclinical inflammatory bowel disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory disease (IMID) of the gastrointestinal tract and includes two subtypes: Crohn's disease and ulcerative colitis. It is well-recognized that IBD is associated with a complex multifactorial aetiology that includes genetic predisposition and environmental exposures, with downstream dysregulation of systemic immune function and host-microbial interactions in the local environment in the gut. Evidence to support the notion of a multistage development of IBD is growing, as has been observed in other IMIDs such as rheumatoid arthritis and systemic lupus erythematosus. With the rising worldwide incidence of IBD, it is increasingly important to understand the complex interplay of pathological events during the different stages of disease development to enable IBD prediction and prevention strategies. In this article, we review comprehensively the current evidence pertaining to the preclinical phase of IBD, including at-risk, initiation and expansion phases. We also discuss the framework of preclinical IBD, expanding on underlying pathways in IBD development, future research directions and IBD development in the context of other IMIDs.

Diagnostic value of anti-integrin αvβ6 antibodies in ulcerative colitis

Ulcerative colitis (UC)-related mucosal inflammation is characterized by the production of various autoantibodies with limited clinical relevance. Recent studies have shown that circulating levels of IgG against integrin αvβ6 are increased in UC patients as compared to Crohn's disease (CD) patients and healthy controls (HC). The present study assessed the diagnostic value of circulating IgG anti-αvβ6 in UC. Sera were prospectively collected from 108 outpatients with UC, 103 patients with CD, and 62 HC, and the levels of IgG anti-αvβ6 were measured using a commercially available ELISA kit. The cut-off for positive results was defined as the 95th percentile of the values of the autoantibodies in HC serum samples. Levels of IgG anti-αvβ6 were significantly higher in UC than in CD patients, including those with colonic localization, and HC. Fifty-six of the 108 (51.8%) UC patients had a positive test whereas only 17/103 (16.5%) patients with CD, and among these, 4/16 (25%) patients with colonic CD, were positive. In UC, there was no statistical difference between patients with IgG anti-αvβ6 positivity and those negative in terms of clinical disease activity, fecal calprotectin values, and disease extent. The sensitivity, specificity, predictive positive value, and predictive negative value of the test to differentiate between UC and CD were 51.9% (C.I.42.4-61.3), 83.5% (C.I. 76.3-90.7), 76.7% (C.I. 67.0-86.4), and 62.3% (C.I. 54.2-70.4) respectively. Our study confirms that anti-αvβ6 antibodies are demonstrable in the serum of the majority of UC patients and suggests the necessity of further research to understand if the anti-αvβ6 antibody determination could have a place in the clinical decision-making of IBD.

Clinical Validity of Anti-Proteinase 3 Antibodies in Patients with Inflammatory Bowel Disease: A Short Meta-Analysis

Anti-neutrophil cytoplasmic antibodies (ANCA) directed to proteinase 3 (PR3) represent highly established markers for patients with ANCA-associated vasculitis (AAV). PR3-ANCA have also demonstrated utility in the management of inflammatory bowel disease (IBD). More specifically, PR3-ANCA discriminate individuals with ulcerative colitis (UC) from Crohn's disease (CD) patients and are associated with disease severity, activity, and treatment non-response. Here, we aim to summarize the current data on the diagnostic utility of PR3-ANCA in IBD. A structured, systematic literature review, including three electronic databases, was conducted on June 6th, 2023, to identify studies assessing the diagnostic accuracy of the QUANTA Flash® PR3 assay in UC vs. CD patients. Electronic searches were supplemented by hand searching. A hierarchical, bivariate, mixed-effect meta-analysis was conducted using the metandi function, as per the Cochrane collaboration recommendations. Study quality was assessed using the QUADAS-2 tool, which considers the risk of bias and applicability. Six out of a hundred and eleven citations met the inclusion criteria and reported QUANTA Flash® PR3 diagnostic accuracy in UC vs. CD (UC, n = 667, CD, n = 682 patients). The sensitivity/specificity point estimate for UC was 34.9%/95.9%. This resulted in a Diagnostic Odds Ratio (DOR) of 12.6. The risk of bias was low in the index test and reference standard domains. Four of the six studies (67%) showed an unclear risk of bias in patient selection and in flow and timing domains. All studies had low concerns about applicability in all the domains. PR3-ANCA measured with the QUANTA Flash® PR3 assay represent novel diagnostic markers in IBD and enables discrimination between UC and CD.

Plasma anti-myosin autoantibodies in the diagnosis of necrotizing enterocolitis

We aimed to assess whether autoantibodies can be used as biomarkers for necrotizing enterocolitis (NEC) and applied for its early diagnosis. A prospective observational study was conducted in neonates with suspected NEC abdominal distension (the developmental study), which consisted of 50 neonates finally divided into NEC (n = 24) and non-NEC (n = 26) cohorts based on follow-up results. Serum samples were collected within 48 h of illness onset and used for screening NEC-associated plasma autoantibodies by autoantigen microarray. Additionally, we validated anti-myosin autoantibodies by enzyme-linked immunosorbent assay (ELISA) in an independent validation study, for which we selected plasma samples within 48 h of onset of NEC (n = 38) and samples of gestational age- and weight-matched controls (n = 13). Autoantigen microarray revealed that both IgG and IgM anti-myosin autoantibodies in plasma from neonates with NEC were significantly higher than those in neonates with other diagnoses. ELISA showed that plasma anti-myosin autoantibodies increased in the NEC cohort, with 1.5-fold higher levels than in the non-NEC cohort. Anti-myosin autoantibodies were able to distinguish NEC from non-NEC, achieving an area under the curve (AUC) of 0.8856 (95% confidence interval (CI): 0.7918-0.9795), with sensitivity of 81.58% and specificity of 76.93%. Plasma anti-myosin autoantibodies were significantly higher in all three subtypes of NEC (P < 0.0001 for NEC I; P = 0.0018 for NEC II; P = 0.0011 for NEC III), especially in NEC stage I than that in the non-NEC controls.

CONCLUSION

Anti-myosin autoantibodies may be applied as a promising diagnostic marker for NEC, especially for NEC stage I.

WHAT IS KNOWN

• Intestinal damage and self-antigen exposure may lead to increased autoantibodies, and they are widely used as biomarkers for diagnosing inflammatory bowel disease. • Necrotizing enterocolitis (NEC) is a devastating disease with overwhelming inflammation and immune dysregulation.

WHAT IS NEW

• Increased autoantibodies were present in patients with NEC, even before typical X-ray manifestations. • Anti-myosin autoantibodies may be applied as a promising diagnostic marker for NEC.

Current and emerging biomarkers for ulcerative colitis

INTRODUCTION

Ulcerative colitis (UC) is a chronic illness requiring lifelong management that could be enhanced by personalizing care using biomarkers.

AREAS COVERED

The main biomarker discovery modalities are reviewed, highlighting recent results across the spectrum of applications, including diagnostics (serum anti-αvβ6 antibodies achieving an area under the curve [AUC] = 0.99; serum oncostatin M AUC = 0.94), disease activity assessment (fecal calprotectin and serum trefoil factor 3: AUC > 0.90), prognostication of the need for treatment escalation (whole blood transcriptomic panels and CLEC5A/CDH2 ratio: AUC > 0.90), prediction of treatment response, and early identification of patients with subclinical disease. The use of established biomarkers is discussed, along with new evidence regarding autoantibodies, proteins, proteomic panels, transcriptomic signatures, deoxyribonucleic acid methylation patterns, and UC-specific glycomic and metabolic disturbances.

EXPERT OPINION

Novel biomarkers will pave the way for optimized UC care. However, validation, simplification, and direct clinical translation of complex models may prove challenging. Currently, few candidates exist to assess key characteristics, such as UC susceptibility, histological disease activity, drug response, and long-term disease behavior. Further research will likely not only reveal new tools to tackle these issues but also contribute to understanding UC pathogenesis mechanisms.

Recent Advances and Potential Multi-Omics Approaches in the Early Phases of Inflammatory Bowel Disease

Inflammatory bowel disease leads to debilitating gastrointestinal symptoms and reduced quality of life, resulting in a significant burden on healthcare utilization and costs. Despite substantial advancements in diagnosis and treatment, there may still be considerable delays in diagnosing some patients. To reduce disease progression before the full disease spectrum appears and improve prognostic outcomes, several strategies have concentrated on early intervention and prevention. Recent evidence shows that initial immune response changes and endoscopic lesions may exist for years before diagnosis, implying the existence of a preclinical phase of inflammatory bowel disease comparable to findings in other immune-mediated disorders. In this review, we highlight the most relevant findings regarding preclinical inflammatory bowel disease and the prospective role of novel omics techniques in this field.