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

Unveiling the overlooked fungi: the vital of gut fungi in inflammatory bowel disease and colorectal cancer

The fungi of the human microbiota play important roles in the nutritional metabolism and immunological balance of the host. Recently, research has increasingly emphasised the role of fungi in modulating inflammation in intestinal diseases and maintaining health in this environment. It is therefore necessary to understand more clearly the interactions and mechanisms of the microbiota/pathogen/host relationship and the resulting inflammatory processes, as well as to offer new insights into the prevention, diagnosis and treatment of inflammatory bowel disease (IBD), colorectal cancer (CRC) and other intestinal pathologies. In this review, we comprehensively elucidate the fungal-associated pathogenic mechanisms of intestinal inflammation in IBD and related CRC, with an emphasis on three main aspects: the direct effects of fungi and their metabolites on the host, the indirect effects mediated by interactions with other intestinal microorganisms and the immune regulation of the host. Understanding these mechanisms will enable the development of innovative approaches based on the use of fungi from the resident human microbiota such as dietary interventions, fungal probiotics and faecal microbiota transplantation in the prevention, diagnosis and treatment of intestinal diseases.

Biochemical Modulators of Tight Junctions (TJs): Occludin, Claudin-2 and Zonulin as Biomarkers of Intestinal Barrier Leakage in the Diagnosis and Assessment of Inflammatory Bowel Disease Progression

BACKGROUND

Considering the increasing worldwide prevalence of inflammatory bowel disease (IBD), the early diagnosis of this disease is extremely important. However, non-invasive diagnostic methods remain limited, while invasive techniques are the most commonly used in daily practice. Therefore, there is a serious need to find new non-invasive biomarkers of IBD.

METHODS

The serum profiles of occludin, claudin-2, and zonulin were assessed in IBD patients using the ELISA method. The levels of the analyzed biomarkers were measured before and after a year of anti-inflammatory treatment, which was a tumor necrosis factor α (TNF-α) inhibitor (adalimumab) in patients with ulcerative colitis (UC) and conventional therapy in patients with Crohn's disease (CD).

RESULTS

In IBD patients, the serum level of occludin (p < 0.001) decreased compared to healthy individuals, while the level of claudin-2 (p < 0.001) increased. Additionally, zonulin (p < 0.01) concentration increased in CD patients compared to the control group. The highest diagnostic ability was presented by occludin measurements with the area under the curve (AUC) of 0.959 (95% CI 0.907-1) in UC and 0.948 (95% CI 0.879-1) in CD. Claudin-2 also demonstrated very good ability in diagnosing UC and CD with AUC values of 0.864 (95% CI 0.776-0.952) and 0.896 (95% CI 0.792-0.999), respectively. The ability of zonulin to diagnose CD was estimated as good with an AUC of 0.74 (95% CI 0.598-0.881). Moreover, a significant correlation was identified between C-reactive protein (CRP), claudin-2 (r = -0.37; p < 0.05), and zonulin (r = -0.44; p < 0.05) in UC patients. Treatment with adalimumab improved the level of occludin, claudin-2, and zonulin in UC patients, while anti-inflammatory conventional therapy decreased the concentration of zonulin in CD.

CONCLUSIONS

Occludin and claudin-2 measurements present significant utility in diagnosing both UC and CD, while zonulin assessments may be useful in CD diagnosis. Additionally, claudin-2 and zonulin measurements may be helpful in evaluating the intensity of the inflammatory process. Anti-TNF-α treatment improved the value of occludin, claudin-2, and zonulin, indicating its beneficial effect on the integrity of tight junctions in UC.

Long non-coding RNAs as pathophysiological regulators, therapeutic targets and novel extracellular vesicle biomarkers for the diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease of the gastrointestinal (GI) system that includes two groups, Crohn's disease (CD) and ulcerative colitis (UC). To cope with these two classes of IBD, the investigation of pathogenic mechanisms and the discovery of new diagnostic and therapeutic approaches are crucial. Long non-coding RNAs (lncRNAs) which are non-coding RNAs with a length of longer than 200 nucleotides have indicated significant association with the pathology of IBD and strong potential to be used as accurate biomarkers in diagnosing and predicting responses to the IBD treatment. In the current review, we aim to investigate the role of lncRNAs in the pathology and development of IBD. We first describe recent advances in research on dysregulated lncRNAs in the pathogenesis of IBD from the perspective of epithelial barrier function, intestinal immunity, mitochondrial function, and intestinal autophagy. Then, we highlight the possible translational role of lncRNAs as therapeutic targets, diagnostic biomarkers, and predictors of therapeutic response in colon tissues and plasma samples. Finally, we discuss the potential of extracellular vesicles and their lncRNA cargo in the pathophysiology, diagnosis, and treatment of IBD.

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Circulating Profiles of Serum Proguanylin, S100A12 Protein and Pentraxin 3 as Diagnostic Markers of Ulcerative Colitis

The aim of this research was to investigate potential new biomarkers which could be used in the clinical practice of ulcerative colitis (UC). Given the crucial role of intestinal barrier integrity and inflammation in the pathogenesis of UC, the serum profile of proteins linked to intestinal barrier and pro-inflammatory neutrophil products may be useful in diagnosing and monitoring the activity of the disease. We measured serum levels of proguanylin (pro-GN), S100A12, and pentraxin 3 (PTX3) in 31 patients with UC before and after a year of biological treatment, as well as in 20 healthy individuals. Significant differences in the serum profiles of pro-GN (5.27 vs. 11.35, p < 0.001), S100A12 (39.36 vs. 19.74, p < 0.001) and PTX3 (3197.05 vs. 1608.37, p < 0.001) were observed between pre-treatment patients with UC and healthy individuals. Furthermore, in UC patients prior to treatment, the levels of S100A12 (p < 0.0005; r = 0.628) and PTX3 (p < 0.05; r = 0.371) were correlated with disease activity as measured by the Mayo scale. Following a year of biological treatment with adalimumab, the concentration of pro-GN significantly increased (5.27 vs. 6.68, p < 0.005) in the blood of UC patients, while the level of PTX-3 decreased (3197.05 vs. 1946.4, p < 0.0001). Our study demonstrates the usefulness of pro-GN, S100A12, and PTX3 measurements in diagnosing and monitoring the activity of UC.

Fourier-transform infrared spectroscopy: a universal optical sensing technique with auspicious application prospects in the diagnosis and management of autoimmune diseases

Autoimmune diseases (AIDs) are poorly understood clinical syndromes due to breakdown of immune tolerance towards specific types of self-antigens. They are generally associated with an inflammatory response mediated by lymphocytes T, autoantibodies or both. Ultimately, chronic inflammation culminates in tissue damages and clinical manifestations. AIDs affect 5% of the world population, and they represent the main cause of fatality in young to middle-aged females. In addition, the chronic nature of AIDs has a devastating impact on the patient's quality of life. It also places a heavy burden on the health care system. Establishing a rapid and accurate diagnosis is considered vital for an ideal medical management of these autoimmune disorders. However, for some AIDs, this task might be challenging. Vibrational spectroscopies, and more particularly Fourier-transform infrared (FTIR) spectroscopy, have emerged as universal analytical techniques with promising applications in the diagnosis of various types of malignancies and metabolic and infectious diseases. The high sensitivity of these optical sensing techniques and their minimal requirements for test reagents qualify them to be ideal analytical techniques. The aim of the current review is to explore the potential applications of FTIR spectroscopy in the diagnosis and management of most common AIDs. It also aims to demonstrate how this technique has contributed to deciphering the biochemical and physiopathological aspects of these chronic inflammatory diseases. The advantages that can be offered by this optical sensing technique over the traditional and gold standard methods used in the diagnosis of these autoimmune disorders have also been extensively discussed.

What Do NAFLD, Liver Fibrosis, and Inflammatory Bowel Disease Have in Common? Review of the Current Literature

Liver disease is one of the most common extraintestinal manifestations of inflammatory bowel disease (IBD). Often the course of liver disease is associated with an exacerbation of the underlying disease (Crohn’s Disease/Ulcerative Colitis). Nonalcoholic steatohepatitis encompasses a wide spectrum of liver damage. The most common form is nonalcoholic fatty liver disease (NAFLD) (75–80%), and the less common but more dangerous form is nonalcoholic steatohepatitis (NASH). NAFLD is now the most common cause of chronic liver disease in developed countries and the leading indication for liver transplantation in the United States. Genetic, demographic, clinical, and environmental factors can play a role in the pathogenesis of NAFLD. The increasing prevalence of NAFLD is associated with a widespread obesity epidemic, metabolic complications, including hypertension, type 2 diabetes, and dyslipidaemia. Some of the most common manifestations of IBD are liver, biliary tract, and gallbladder diseases. The liver fibrosis process has a complex pathophysiology and is often dependent on exogenous factors such as the treatment used and endogenous factors such as the gut microbiome. However, the factors that link IBD and liver fibrosis are not yet clear. The main purpose of the review is to try to find links between IBD and selected liver diseases and to identify knowledge gaps that will inform further research.

Gum-gut axis: The potential role of salivary biomarkers in the diagnosis and monitoring progress of inflammatory bowel diseases

The gut mucosa is an extension of the oral mucosa, and both are directly linked. There is emerging evidence that pathogenic oral microbiome contributes greatly to the risk of developing Inflammatory Bowel Disease (IBD). Dysbiosis of the oral microbiota can interfere with the host immune system's ability to respond normally, thereby increasing the development of periodontitis which raises the risk of IBD, cancer, rheumatoid arthritis, cardiovascular disease, and other complex disease processes. Salivary biomarkers are possibly important for determining the incidence, severity, and remission of IBD. Nevertheless, clinical translation of biomarker knowledge from lab to clinical practice needs further studies that identify biomarkers related to the transitional phase between healthy and unhealthy. In this review, the bidirectional pathway between the gut and the oral cavity was investigated and several aspects were discussed.

Clinical and biochemical status of patients with ulcerative collitis

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic inflammatory conditions of the gastrointestinal tract characterized by a relapsing and remitting course. Aim - to analyze clinical data and the most significant hematological and biochemical blood parameters used for diagnosis in patients with ulcerative colitis. Materials and methods. Between 2020 and 2021 examined 50 patients with the diagnosis "Ulcerative colitis" living in the Samara region. The diagnosis of ulcerative colitis was confirmed by a combination of clinical, radiological, endoscopic, and histopathological criteria generally accepted for inflammatory bowel diseases. A hematological blood test was performed on an automatic hematological analyzer Sysmex KX-21N, Japan, and a biochemical blood test was performed on an automatic biochemical analyzer Hitachi 902, Japan. Results. In the biochemical analysis of blood, an increase in the content of C-reactive protein in the blood is expected in 64% of patients. In 40% of patients, the concentration of total protein and electrolytes decreases. An increase in glucose levels was revealed in 44% of patients, in 10% of cases, a decrease in creatinine concentration, an increase in the activity of ALAT and ASAT was noted in 6 and 4% of cases, respectively. Reduced urea levels are noted in 6% of patients. Conclusion. As a result of the study, the data necessary for the diagnosis and monitoring of the effectiveness of the treatment of ulcerative colitis were obtained.

Quantitative real-time PCR analysis of bacterial biomarkers enable fast and accurate monitoring in inflammatory bowel disease

Inflammatory bowel diseases (IBD) affect millions of people worldwide with increasing incidence. Ulcerative colitis (UC) and Crohn's disease (CD) are the two most common IBDs. There is no definite cure for IBD, and response to treatment greatly vary among patients. Therefore, there is urgent need for biomarkers to monitor therapy efficacy, and disease prognosis. We aimed to test whether qPCR analysis of common candidate bacteria identified from a patient's individual fecal microbiome can be used as a fast and reliable personalized microbial biomarker for efficient monitoring of disease course in IBD. Next generation sequencing (NGS) of 16S rRNA gene region identified species level microbiota profiles for a subset of UC, CD, and control samples. Common high abundance bacterial species observed in all three groups, and reported to be associated with IBD are chosen as candidate marker species. These species, and total bacteria amount are quantified in all samples with qPCR. Relative abundance of anti-inflammatory, beneficial Faecalibacterium prausnitzii, Akkermansia muciniphila, and Streptococcus thermophilus was significantly lower in IBD compared to control samples. Moreover, the relative abundance of the examined common species was correlated with the severity of IBD disease. The variance in qPCR data was much lower compared to NGS data, and showed much higher statistical power for clinical utility. The qPCR analysis of target common bacterial species can be a powerful, cost and time efficient approach for monitoring disease status and identify better personalized treatment options for IBD patients.

Differentially Expressed miRNAs in Ulcerative Colitis and Crohn’s Disease

Differential microRNA (miRNA or miR) regulation is linked to the development and progress of many diseases, including inflammatory bowel disease (IBD). It is well-established that miRNAs are involved in the differentiation, maturation, and functional control of immune cells. miRNAs modulate inflammatory cascades and affect the extracellular matrix, tight junctions, cellular hemostasis, and microbiota. This review summarizes current knowledge of differentially expressed miRNAs in mucosal tissues and peripheral blood of patients with ulcerative colitis and Crohn’s disease. We combined comprehensive literature curation with computational meta-analysis of publicly available high-throughput datasets to obtain a consensus set of miRNAs consistently differentially expressed in mucosal tissues. We further describe the role of the most relevant differentially expressed miRNAs in IBD, extract their potential targets involved in IBD, and highlight their diagnostic and therapeutic potential for future investigations.

Enterogenous Microbiotic Markers in the Differential Diagnosis of Crohn's Disease and Intestinal Tuberculosis

Crohn’s disease (CD) is a chronic intestinal disorder characterized by refractory gastrointestinal ulcerations. Intestinal tuberculosis (ITB) is one common intestinal disease in east Asia. The two diseases share similar clinical manifestations and endoscopic characteristics. Thus, it is difficult to establish a definite diagnosis of CD, CD concomitant with ITB (CD-ITB), and ITB in practice. Some enterogeneous microbiotic markers have been applied to differentiate CD and ITB, but it remains unknown how they work for the three groups of patients. The aim of our study was to explore the diagnostic values of these enterogeneous microbiotic markers (ASCA IgG, ASCA IgA, ACCA, Anti-I2 and AMCA) among CD, CD-ITB, and ITB patients. A total of 124 individuals were retrospectively enrolled in this study, namely, 103 CD patients, 10 CD-ITB patients, 9 ITB patients, and 68 healthy controls. The demographic and clinical characteristics of these patients were collected and analyzed. The values of these individual or combined enterogeneous microbiotic markers in diagnosis and classification were assessed in CD, CD-ITB, and ITB patients. ASCA IgG, ASCA IgA, and AMCA could accurately differentiate CD patients from healthy controls with an area under curve (AUC) of 0.688, 0.601, and 0.638, respectively. ASCA IgG was significantly higher in CD patients than in CD-ITB patients (P = 0.0003). The Anti-I2 antibody was appropriate for distinguishing CD-ITB from ITB patients (P = 0.039). In CD patients, ASCA IgG was higher in severe patients than in mild (P <0.0001) and inactive patients (P <0.0001), respectively. AMCA was significantly elevated in severe and moderate patients compared to inactive patients (P = 0.001, P = 0.003, respectively). AMCA was associated with a higher risk of CD-related surgery with a significant P-value of 0.0038. In our cohort, ASCAs and AMCA could accurately distinguish CD from healthy controls with an acceptable AUC. A combination of elevated ASCA IgG and AMCA antibodies established a higher sensitivity in differentiating CD from healthy controls. Elevated ASCA IgG demonstrated a differential diagnostic value between CD and CD-ITB. Anti-I2 could also distinguish CD-ITB from ITB. The level of AMCA was associated with both disease severity and CD-related surgery. Likewise, the level of ASCA IgG was also related to disease severity.

Circulating Fibroblast Activation Protein as Potential Biomarker in Patients With Inflammatory Bowel Disease

A major concern in the management of Inflammatory Bowel Disease (IBD) is the absence of accurate and specific biomarkers to drive diagnosis and monitor disease status timely and non-invasively. Fibroblast activation protein (FAP) represents a hallmark of IBD bowel strictures, being overexpressed in stenotic intestinal myofibroblasts. The present study aimed at evaluating the potential of circulating FAP (cFAP) as an accessible blood biomarker of IBD. Quantitative determination of cFAP was performed by enzyme-linked immunosorbent assay on plasma samples prospectively collected from patients with IBD and control subjects. A discrimination model was established on a training set of 50% patients and validated on independent samples. Results showed that cFAP concentration was reduced in patients with IBD when compared to controls (p < 0.0001). Age, sex, smoking, disease location and behavior, disease duration and therapy were not associated with cFAP. The sensitivity and specificity of cFAP in discriminating IBD from controls were 70 and 84%, respectively, based on the optimal cutoff (57.6 ng mL⁻¹, AUC = 0.78). Predictions on the test set had 57% sensitivity, 65% specificity, and 61% accuracy. There was no strong correlation between cFAP and routine inflammatory markers in the patients' population. A subgroup analysis was performed on patients with Crohn's disease undergoing surgery and revealed that cFAP correlates with endoscopic mucosal healing. In conclusion, cFAP deserves attention as a promising blood biomarker to triage patients with suspected IBD. Moreover, it might function as a biomarker of post-operative remission in patients with Crohn's disease.

Linking the IL-17A immune response with NMR-based faecal metabolic profile in IBD patients treated with Mastiha

Dysregulation of intestinal immune response plays a critical role in the pathogenesis of Inflammatory Bowel Disease (IBD). Mastiha's anti-inflammatory properties are well established. Our aim was to investigate Mastiha's regulatory effect on IL-17A serum levels in IBD patients. Alterations of the faecal metabolome as a functional readout of microbial activity were explored. A randomized, double-blind, placebo-controlled, parallel-group design was applied for a total of 3 months in active and 6 months in inactive IBD patients. Serum IL-17A increased significantly in Mastiha group (p = 0.006), and the mean change differed significantly between Mastiha and placebo (p = 0.003) even after adjusting for age, sex and BMI (p = 0.001) in inactive patients. In inactive UC patients IL-17A decreased significantly only in placebo (p = 0.033). No significant differences were detected in active disease. Faecal metabolomics indicated that intervention with Mastiha influenced considerably the metabolic profile of IBD patients in remission exhibiting, in between others, increased levels of glycine and tryptophan. Glycine has been proposed to have a therapeutic effect against IBD, while tryptophan derivatives are involved in immunoregalutory mechanisms, such as the Th17 cells differentiation. Thus, it is quite possible that the immunoregulatory role of Mastiha in quiescent IBD involves the regulation of Th17 cells function and differentiation.

Identification of microRNA-16-5p and microRNA-21-5p in feces as potential noninvasive biomarkers for inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic idiopathic gastrointestinal disease. Increasing evidence suggests that microRNAs (miRNAs) may participate in the pathophysiology of IBD.

METHODS

A miRCURY™ LNA Array and in situ hybridization were employed to screen for differentially expressed miRNAs (DEMs) in fecal specimens from 41 IBD patients (22 ulcerative colitis (UC), 19 Crohn's disease (CD)) and 23 healthy controls (HC). RT-qPCR was performed to confirm the findings. The DEMs target genes and corresponding biological functions were predicted by bioinformatics analysis.

RESULTS

Compared with HC, miR-16-5p in the feces was up-regulated both in UC and CD patients (p < 0.01), while miR-21-5p was up-regulated only in UC patients (p < 0.01). TargetScan 7.2, miRWalk, and miRDB were used to predict 216 public target genes of miR-16-5p and miR-21-5p, and six hub genes (PIK3R1, GRB2, SUZ12, NTRK2, Smurf2, and WWP1) were analyzed using the STRING database and Cytoscape. All the hub genes promote the occurrence and development of IBD-related colorectal cancer.

CONCLUSIONS

The elevated levels of miR-16-5p and miR-21-5p in feces of IBD patients have to guide significance for the noninvasive clinical diagnosis of IBD and have a warning effect on the occurrence of IBD-related colorectal cancer.

Detection of fucosylated haptoglobin using the 10-7G antibody as a biomarker for evaluating endoscopic remission in ulcerative colitis

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, relapsing inflammation of the digestive tract. Although fecal and serum biomarkers have been extremely important and supportive for monitoring of IBD, their low sensitivity and high variability characteristics limit clinical efficacy. Thus, the establishment of better biomarkers is expected. Fucosylation is one of the most important glycosylation modifications of proteins. Fucosylated haptoglobin (Fuc-Hpt) is used as a biomarker for several cancers and inflammation-related diseases. We recently established a novel glycan monoclonal antibody (mAb), designated 10-7G, which recognizes Fuc-Hpt. We developed an enzyme-linked immunosorbent assay (ELISA) to measure serum levels of Fuc-Hpt (10-7G values).

AIM

To investigate the usefulness of the serum 10-7G values as a potential biomarker for monitoring disease activity in IBD.

METHODS

This was a case control study. Intestinal tissues of IBD patients (n = 10) were examined immunohistochemically using the 10-7G mAb. We determined 10-7G values using serum from patients with ulcerative colitis (UC, n = 110), Crohn’s disease (n = 45), acute enteritis (AE, n = 11), and healthy volunteers (HVs) who exhibited normal (n = 20) or high (n = 79) C-reactive protein (CRP) levels at medical check-up. We investigated the correlation between the 10-7G value and various clinical parameters of IBD patients by correlation analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the usefulness of the 10-7G values as a biomarker for clinical and endoscopic remission of UC compared to conventional serum biomarkers.

RESULTS

In the immunohistochemical analysis, positive 10-7G mAb staining was observed in lymphocytes infiltrating into inflammatory sites of the mucosal layer and lymphoid follicles. The 10-7G values were significantly higher in patients with IBD (P < 0.001) and AE (P < 0.05) compared with HVs. In addition, 10-7G values were correlated with clinical examination parameters related to inflammation in patients with UC, particularly the CRP level (rs = 0.525, P = 0.003) and clinical activity index score (rs = 0.435, P = 0.038). However, there was no correlation between 10-7G values and CRP in HVs with high CRP levels, suggesting that the 10-7G values is not the same as a general inflammation biomarker. ROC curve analysis showed that area under the curve (AUC) value of 10-7G values for the diagnosis of endoscopic remission was higher than other biomarkers (AUC value = 0.699).

CONCLUSION

The serum 10-7G value is a novel biomarker for evaluating intestinal inflammation and endoscopic mucosal healing in UC.

Fecal Lactoferrin and Other Stool Markers during Normal Pregnancy and in Inflammatory Bowel Diseases: A Prospective Study and Review of the Literature

Introduction

Management of inflammatory bowel diseases (IBDs) - both Crohn's disease (CD) and ulcerative colitis (UC) - during pregnancy can be challenging since most monitoring tools available in nonpregnant patients are contraindicated.

Objectives

The aim of the study was to test whether fecal inflammatory markers - specifically fecal lactoferrin - physiologically change during normal pregnancy as a prerequisite to use them to monitor IBD activity during pregnancy.

Methods

Fecal lactoferrin was tested in healthy pregnant and nonpregnant women from the same geographic area and age range (18-40 years) - all negative for clinical gastrointestinal tract inflammation. A retrospective review of fecal lactoferrin levels contrasted with the Simple Endoscopic Score for CD, and the Disease Activity Index for UC was also performed in women with active IBDs within the same age range and geographical area.

Results

In 30 nonpregnant subjects, fecal lactoferrin levels were 0.87 ± 1.08 μg/g. In 49 pregnant subjects, levels were 0.59 ± 0.83, 0.87 ± 1.13, and 0.85 ± 1.06 μg/g during the first, second, and third trimester, respectively (p = 0.64), with average levels for the 3 trimesters of 0.81 ± 1.04 μg/g (p = 0.61 compared to nonpregnant subjects). Sequential fecal lactoferrin levels (n = 26) did not differ from one trimester to the other in the individual subjects (p = 0.80). In 45 female IBD patients (27 with CD and 18 with UC), fecal lactoferrin levels were correlated with disease activity as defined by the endoscopic scores: 218, 688, and 1,175 μg/g for CD and 931, 2,088, and 2,509 μg/g for UC, respectively, for mild, moderate, and severe activity.

Conclusions

Fecal lactoferrin levels during normal pregnancy are superimposable to those of nonpregnant women and significantly below levels in women of the same childbearing age with active IBDs. Additional published data - reviewed in this atricle - and our own indicate that fecal lactoferrin and other markers can be potentially used to monitor disease activity in pregnant IBD patients.

The DNA methylome of inflammatory bowel disease (IBD) reflects intrinsic and extrinsic factors in intestinal mucosal cells

Abnormal DNA methylation has been described in human inflammatory conditions of the gastrointestinal tract, such as inflammatory bowel disease (IBD). As other complex diseases, IBD results from the balance between genetic predisposition and environmental exposures. As such, DNA methylation may be the consequence (and potential effector) of both, genetic susceptibility variants and/or environmental signals such as cytokine exposure. We attempted to discern between these two non-excluding possibilities by performing a combined analysis of published DNA methylation data in intestinal mucosal cells of IBD and control samples. We identified abnormal DNA methylation at different levels: deviation from mean methylation signals at site and region levels, and differential variability. A fraction of such changes is associated with genetic polymorphisms linked to IBD susceptibility. In addition, by comparing with another intestinal inflammatory condition (i.e., coeliac disease) we propose that aberrant DNA methylation can also be the result of unspecific processes such as chronic inflammation. Our characterization suggests that IBD methylomes combine intrinsic and extrinsic responses in intestinal mucosal cells, and could point to knowledge-based biomarkers of IBD detection and progression.

[Pancreatic diseases and inflammatory bowel diseases: a random or regular combination?]

Pathology of the pancreas in inflammatory bowel disease (IBD) is more common than in the general population and includes a wide range of manifestations from asymptomatic to severe disorders. Acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, exocrine pancreatic insufficiency, increased pancreatic enzymes and structural duct anomalies are often associated with IBD. They can be either a manifestation of IBD itself or develop independently.

A validated risk stratification tool for detecting high-risk small bowel Crohn's disease

BACKGROUND

Delays in Crohn's disease (CD) diagnosis are positively associated with ileal location and an increased risk of complications.

AIM

To develop a simple risk assessment tool to enable primary care physicians to recognise potential ileal CD earlier, shortening the delay to specialist investigation METHODS: Three cohorts were acquired for this study. Cohort 1 included 61 patients retrospectively identified with ileal CD between 2000 and 2010 and 78 matched controls drawn from a cohort referred for investigation of abdominal symptoms. Cohort 2 included 42 individuals diagnosed with ileal CD and 57 controls identified prospectively. Cohort 3 included an additional 84 individuals with ileal CD and 495 without CD referred for colonoscopy. Clinical symptoms and serological biomarkers were acquired and used to develop a risk prediction algorithm. The algorithm was trained independently on each of the three cohorts and tested on the latter two cohorts.

RESULTS

Altered bowel habit with abdominal pain combined with derangements in white cell count (WCC), albumin and platelet counts were important features in predicting ileal CD (AUC = 0.92, 95% CI = 0.89-0.92). This was validated in cohorts 2 (AUC = 0.96, 95% CI = 0.95-0.98) and 3 (AUC = 0.94, 95% CI = 0.92-0.96). C-reactive protein was independently associated with ileal CD but non-signficant in a multivariate model.

CONCLUSION

A web-based risk stratification tool for ileal CD has been developed from objective and symptom-based criteria. This tool enables primary care physicians to more confidently request urgent specialist assessment for patients identified as at high risk for ileal CD.

Treatment-Specific Composition of the Gut Microbiota Is Associated With Disease Remission in a Pediatric Crohn's Disease Cohort

BACKGROUND

The beneficial effects of antibiotics in Crohn's disease (CD) depend in part on the gut microbiota but are inadequately understood. We investigated the impact of metronidazole (MET) and metronidazole plus azithromycin (MET+AZ) on the microbiota in pediatric CD and the use of microbiota features as classifiers or predictors of disease remission.

METHODS

16S rRNA-based microbiota profiling was performed on stool samples from 67 patients in a multinational, randomized, controlled, longitudinal, 12-week trial of MET vs MET+AZ in children with mild to moderate CD. Profiles were analyzed together with disease activity, and then used to construct random forest models to classify remission or predict treatment response.

RESULTS

Both MET and MET+AZ significantly decreased diversity of the microbiota and caused large treatment-specific shifts in microbiota structure at week 4. Disease remission was associated with a treatment-specific microbiota configuration. Random forest models constructed from microbiota profiles before and during antibiotic treatment with metronidazole accurately classified disease remission in this treatment group (area under the curve [AUC], 0.879; 95% confidence interval, 0.683-0.9877; sensitivity, 0.7778; specificity, 1.000; P < 0.001). A random forest model trained on pre-antibiotic microbiota profiles predicted disease remission at week 4 with modest accuracy (AUC, 0.8; P = 0.24).

CONCLUSIONS

MET and MET+AZ antibiotic regimens in pediatric CD lead to distinct gut microbiota structures at remission. It may be possible to classify and predict remission based in part on microbiota profiles, but larger cohorts will be needed to realize this goal.

Extracellular Matrix Fragments of the Basement Membrane and the Interstitial Matrix Are Serological Markers of Intestinal Tissue Remodeling and Disease Activity in Dextran Sulfate Sodium Colitis

BACKGROUND

Chronic intestinal inflammation results in tissue damage partly caused by an increase in matrix metalloproteinases (MMP) activity causing degradation of extracellular matrix (ECM) proteins. We studied intestinal tissue remodeling by quantifying ECM protein fragments in serum in dextran sulfate sodium (DSS)-induced colitis, to investigate ECM protein fragments as serological biomarkers of intestinal tissue remodeling and disease activity.

METHODS

Male Sprague-Dawley rats received 5% DSS in drinking water for 5 days followed by 11 days with regular water. Disease activity index (DAI) was scored daily. Serum was collected on day 0, 6, 7, and 16. ELISAs were used to quantify MMP-derived remodeling fragments of basement membrane type IV collagen (C4M and PRO-C4) and interstitial matrix type III collagen (C3M and rPRO-C3).

RESULTS

In DSS rats, serum levels relative to baseline of C4M, PRO-C4, and C3M were elevated (P < 0.01; P < 0.001; P < 0.001) at day 7, which declined at day 16. Levels of rPRO-C3 were lower in DSS rats at day 7 and increased to normal levels at day 16. The ratio between C3M and rPRO-C3 showed an overall degradation (P < 0.0001) of collagen type III in DSS rats at day 7, which correlated to the DAI (r² = 0.5588, P < 0.0001).

CONCLUSION

Our data suggest that remodeling of the basement membrane (C4M and PRO-C4) and the interstitial matrix (C3M and rPRO-C3) increased during DSS-induced colitis and declined with reversal of the disease. Thus, serological biochemical biomarkers of the ECM reflect tissue remodeling and could be studied as markers of disease activity in IBD.

Severe colitis after PD-1 blockade with nivolumab in advanced melanoma patients: potential role of Th1-dominant immune response in immune-related adverse events: two case reports

BACKGROUND

Nivolumab is an immune checkpoint inhibitor specific to the programmed death 1 (PD-1) receptor. Nivolumab has shown clinical responses in many malignancies. Although immune-related adverse events (irAEs) associated with nivolumab are largely tolerable, severe irAEs have occurred in some patients. However, the mechanisms underlying the development of irAEs are not fully clarified.

CASE PRESENTATION

We report 2 patients with metastatic melanoma who developed colitis, an irAEs caused by nivolumab. Both patients experienced colitis after nivolumab administration. Pathological examination of the colon showed robust infiltration of CD8⁺ cells and T-bet expressing CD4⁺ cells in both cases, indicating helper T cells (Th) 1 to be responsible for the dominant response. Additionally, we observed the serum C-reactive protein level (CRP) as well as interleukin-6 (IL-6) reflected the clinical course of irAEs clearly in the two cases.

CONCLUSION

Our two cases suggested that the development of irAEs due to nivolumab is associated with Th1 dominant response. CRP as well as IL-6 was found to be a potential biomarker for irAEs. Our findings may help to understand the mechanisms underlying irAEs caused by nivolumab and manage irAEs in clinical practice.

The vitamin D positive feedback hypothesis of inflammatory bowel diseases

While it appears that there are a variety of factors that exacerbate IBD, it is frustrating that symptoms can persist and worsen even when environmental insults are removed. We suggest that there may be a positive feedback loop which perpetuates the inflammatory response in IBD patients. The loop is triggered by vitamin D deficiency which reduces calcium uptake. Lowered vitamin D and calcium interfere with anti-inflammatory pathways. Inflammation of the mucosa inhibits absorption of calcium and thus perpetuates the reduced anti-inflammatory response. A number of predictions follow from this hypothesis and are supported by geographic and lifestyle patterns in IBD incidence and prevalence.

Quantitative assessment of mucosal architecture using computer-based analysis of confocal laser endomicroscopy in inflammatory bowel diseases

BACKGROUND AND AIMS

Confocal laser endomicroscopy (CLE) might discriminate mucosal lesions between Crohn's disease (CD) and ulcerative colitis (UC). However, the analysis of CLE images requires time-consuming methods, a long training time, and potential impediments, such as significant interobserver variability. Therefore, we developed a computer-based method to analyze mucosal architecture from CLE images and discriminate between healthy subjects and patients with inflammatory bowel disease (IBD) as well as between UC and CD patients.

METHODS

We retrospectively screened patients who had undergone CLE either for an evaluation of IBD in remission or for colorectal cancer screening (control subjects) between 2009 and 2016. We assessed 14 morphologic and functional parameters in each CLE recording from 23 CD patients, 27 UC patients, and 9 control patients. Next, we constructed 2 scores, 1 for the IBD diagnosis and 1 for the differential diagnosis between UC and CD.

RESULTS

In IBD patients, the mean intercrypt distance, wall thickness, and fluorescein leakage through the colonic mucosa were significantly increased compared with control patients by 155%, 188%, and 297%, respectively (P < .05). In UC patients, the same parameters were significantly increased by 109%, 117%, and 174%, respectively (P < .05), compared with CD patients. IBD diagnosis had 100% (95%CI, 93%; 100%) sensitivity and 100% (95%CI, 66%; 100%) specificity. IBD differential diagnosis provided discrimination of UC from CD patients with 92% (95%CI, 75%; 99%) sensitivity and 91% (95%CI, 72%; 99%) specificity.

CONCLUSIONS

Confirming these results using prospective validation cohorts can substantiate that computer-based analysis of CLE images may provide new biomarkers for the diagnosis and characterization of IBD.

Acute pancreatitis as an initial presentation of Crohn's disease: A case report

Acute pancreatitis (AP) is not commonly known to be an extra-intestinal manifestations of Crohn's disease (CD). Several cases have been reported discussing the relation of AP with CD. However, no specific etiological factors for pancreatitis were found, which appears to support the possibility of a relationship between AP and CD. We report a 30-year-old male present with generalized abdominal pain associated with watery diarrhea. Diagnosis of AP was made. A CT abdomen showed pancreatic inflammation with a terminal ileum thickening. Colonoscopy with multiple biopsy was done for the patient, which confirmed the diagnosis of CD. The patient started on adalimumab for 6 months, showed good response, and became symptomatically free. No recurrent attacks after 2 years of follow-up. The association between AP and CD is not yet clear. Therefore, patients presenting with idiopathic pancreatitis should be investigated to rule out the coexistence of IBD for better outcome.

The emerging role of lncRNAs in inflammatory bowel disease

Dysregulation of long noncoding RNA (lncRNA) expression is linked to the development of various diseases. Recently, an emerging body of evidence has indicated that lncRNAs play important roles in the pathogenesis of inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative Colitis (UC). In IBD, lncRNAs have been shown to be involved in diverse processes, including the regulation of intestinal epithelial cell apoptosis, association with lipid metabolism, and cell–cell interactions, thereby enhancing inflammation and the functional regulation of regulatory T cells. In this review, we aim to summarize the current knowledge regarding the role of lncRNAs in IBD and highlight potential avenues for future investigation. We also collate potentially immune-relevant, IBD-associated lncRNAs identified through a built-by association analysis with respect to their neighboring protein-coding genes within IBD-susceptible loci. We further underscore their importance by highlighting their enrichment for various aspects of immune system regulation, including antigen processing/presentation, immune cell proliferation and differentiation, and chronic inflammatory responses. Finally, we summarize the potential of lncRNAs as diagnostic biomarkers in IBD.

Studying long noncoding RNAs (lncRNAs) may improve diagnosis and treatment of inflammatory bowel disease (IBD). These RNAs are found between genes in DNA regions previously thought to be “junk,” and have recently been shown to be important in development of various diseases. IBD, which includes both Crohn’s disease and ulcerative colitis, damages the digestive tract lining, causing pain and chronic diarrhea. A better understanding of IBD’s complex causes is needed to identify more effective treatments. Flemming Pociot at the Steno Diabetes Center in Gentofte, Denmark, and co-workers reviewed recent research linking lncRNAs and IBD. They discuss how lncRNAs’ roles in immunity and inflammation influence IBD development, describing how particular lncRNAs are related to IBD. Promising avenues for further research are highlighted, including the use of lncRNAs as biomarkers of IBD, which can be difficult to diagnose.

Proteomics and Lipidomics in Inflammatory Bowel Disease Research: From Mechanistic Insights to Biomarker Identification

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. Ulcerative colitis and Crohn's disease are the major manifestations of IBD. While our understanding of IBD has progressed in recent years, its etiology is far from being fully understood, resulting in suboptimal treatment options. Complementing other biological endpoints, bioanalytical "omics" methods that quantify many biomolecules simultaneously have great potential in the dissection of the complex pathogenesis of IBD. In this review, we focus on the rapidly evolving proteomics and lipidomics technologies and their broad applicability to IBD studies; these range from investigations of immune-regulatory mechanisms and biomarker discovery to studies dissecting host⁻microbiome interactions and the role of intestinal epithelial cells. Future studies can leverage recent advances, including improved analytical methodologies, additional relevant sample types, and integrative multi-omics analyses. Proteomics and lipidomics could effectively accelerate the development of novel targeted treatments and the discovery of complementary biomarkers, enabling continuous monitoring of the treatment response of individual patients; this may allow further refinement of treatment and, ultimately, facilitate a personalized medicine approach to IBD.

Pancreatic Involvement in Inflammatory Bowel Disease: A Review

Inflammatory bowel disease (IBD) is a multisystemic disease, and pancreatic manifestations of IBD are not uncommon. The incidence of several pancreatic diseases in Crohn’s disease and ulcerative colitis is more frequent compared to the general population. Pancreatic manifestations in IBD include a wide heterogenic group of disorders and abnormalities of the pancreas and range from mild self-limited diseases to severe disorders. Acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, pancreatic autoantibodies, exocrine pancreatic insufficiency and asymptomatic imaging and laboratory abnormalities are included in related-IBD pancreatic manifestations. Involvement of the pancreas in IBD may be the result of IBD itself or of medications used.

Circulating and Fecal microRNAs as Biomarkers for Inflammatory Bowel Diseases

BACKGROUND

Assessment of the disease activity in inflammatory bowel disease (IBD) is essential for adequate treatment management and reliable noninvasive biomarkers for verification of mucosal healing are still needed. MicroRNAs (miRNAs) are differentially expressed in IBD and cancer. We aimed to evaluate the potential of circulating and fecal miRNAs as diagnostic biomarkers for IBD.

METHODS

In this proof-of-principle study we used 2 independent patient cohorts. Testing cohort (n = 96) included serum and fecal samples from controls (n = 35) and IBD patients (n = 61) including 43 patients with Crohn's disease (CD), 18 with ulcerative colitis (UC) with an active disease (n = 38), or in remission (n = 23). Validation cohort included fecal samples from patients with calprotectin/endoscopy-confirmed active disease (n = 30) or in remission (n = 15). Target-based approach (miR-16, miR-21, miR-155, and miR-223) has been used to evaluate miRNA expression.

RESULTS

Sera samples from IBD patients showed higher level of miR-16, miR-21, and miR-223, but not miR-155, compared to controls and was higher in CD than in UC patients. Much stronger miRNA expression changes were observed in feces from IBD patients for all studied miRNAs with highest expression of miR-155 and miR-223 in testing and validation cohorts. MiRNA expression correlated with clinical remission, however, only fecal but not circulating miRNAs, correlated with surrogate parameters such as fecal calprotectin or C-reactive protein.

CONCLUSIONS

Our data provide a novel evidence for differential expression level of fecal miRNAs in IBD. We demonstrate that miRNAs in feces correlate with disease activity and may be considered as potential tool for the further biomarker research in IBD. 10.1093/ibd/izy046_video1izy046.video15794822319001.

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

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

Plasma microRNA Profile Differentiates Crohn's Colitis From Ulcerative Colitis

BACKGROUND

Inflammatory bowel disease (IBD) is commonly divided into 2 entities: Crohn's disease (CD) and ulcerative colitis (UC). Differentiating between these entities when dealing with IBD confined to the colon is important, especially when planning surgical treatment. Due to ambiguous histological or endoscopic findings, accurate diagnosis is not possible in up to 15% of cases. The aim of this study was to determine whether plasma microRNAs (miRNAs) can help differentiate Crohn's colitis (CC) from ulcerative colitis.

METHODS

Patients with isolated CC and with UC were enrolled in our study from January 2010 to May 2016. Peripheral blood was collected, and total RNA was isolated from plasma. Screening was performed for 380 common miRNAs. miRNAs that were differentially expressed between these 2 groups were chosen, and their differential expression was confirmed using single miRNA assays in a larger sample size. A predictive model was generated using these data. Significantly differentially expressed miRNAs were then validated utilizing the predictive model to assess blinded data from the single assays.

RESULTS

Screening was performed on 8 patients from each group. Seven differentially expressed miRNAs were chosen for single assay confirmation. Two miRNAs (miR-598, miR-642) were consistently different between the patient groups (P = 0.013, P = 0.005). Using blinded data, these 2 miRNAs were validated using the predictive model, achieving an overall accuracy of 75% (95% confidence interval, 40.7-92.9).

CONCLUSIONS

We identified 2 plasma miRNAs that differentiated CC from UC. Our data indicate the promise and feasibility of a plasma miRNA-based assay to distinguish between these 2 conditions.

Proteomics in Inflammatory Bowel Disease: Approach Using Animal Models

Recently, proteomics studies have provided important information on the role of proteins in health and disease. In the domain of inflammatory bowel disease, proteomics has shed important light on the pathogenesis and pathophysiology of inflammation and has contributed to the discovery of some putative clinical biomarkers of disease activity. By being able to obtain a large number of specimens from multiple sites and control for confounding environmental, genetic, and metabolic factors, proteomics studies using animal models of colitis offered an alternative approach to human studies. Our aim is to review the information and lessons acquired so far from the use of proteomics in animal models of colitis. These studies helped understand the importance of different proteins at different stages of the disease and unraveled the different pathways that are activated or inhibited during the inflammatory process. Expressed proteins related to inflammation, cellular structure, endoplasmic reticulum stress, and energy depletion advanced the knowledge about the reaction of intestinal cells to inflammation and repair. The role of mesenteric lymphocytes, exosomes, and the intestinal mucosal barrier was emphasized in the inflammatory process. In addition, studies in animal models revealed mechanisms of the beneficial effects of some therapeutic interventions and foods or food components on intestinal inflammation by monitoring changes in protein expression and paved the way for some new possible inflammatory pathways to target in the future. Advances in proteomics technology will further clarify the interaction between intestinal microbiota and IBD pathogenesis and investigate the gene-environmental axis of IBD etiology.

IBD血清学标志物的临床应用前景

炎症性肠病(inflammatory bowel disease, IBD)是一种病因不明的慢性非特异性肠道炎症性疾病, 包括溃疡性结肠炎(ulcerative colitis, UC)和克罗恩病(Crohn's disease, CD). 目前IBD的诊断及临床过程主要依据其临床表现、常规检验、影像学特征、内镜所见及组织病理综合判断, 但远未满足临床实践. 因此, 寻找一种简单、准确的诊断方法成为目前亟待解决的问题. 迄今, IBD相关血清学标志物的应用对IBD的诊断与鉴别诊断、疾病严重程度界定、疗效判断和预后评估均凸显出其临床优势. 本文就近年来IBD血清学标志物的研究及其临床应用前景作一述评.

Effectiveness of adalimumab for the treatment of ulcerative colitis in clinical practice: comparison between anti-tumour necrosis factor-naïve and non-naïve patients

BACKGROUND

Ulcerative colitis (UC) treatment is focused to achieve mucosal healing, avoiding disease progression. The study aimed to evaluate the real-world effectiveness of adalimumab (ADA) in UC and to identify predictors of remission to ADA.

METHODS

This cohort study used data from the ENEIDA registry. Clinical response, clinical remission, endoscopic remission, adverse events (AE), colectomy, and hospitalisations were evaluated; baseline characteristics and biological parameters were compared to determine predictors of response.

RESULTS

We included 263 patients (87 naïve and 176 previously exposed to anti-tumour necrosis factor alpha, TNF). After 12 weeks, clinical response, clinical remission, and endoscopic remission rates were 51, 26, and 14 %, respectively. The naïve group demonstrated better response to treatment than the anti-TNF-exposed group at short-term. Clinical and endoscopic remission within 1 year of treatment was better in the naïve group (65 vs. 49 and 50 vs. 35 %, respectively). The rates of AE, dose-escalation, hospitalisations, and colectomy during the first year were higher in anti-TNF-exposed patients (40, 43, and 27 % vs. 26, 21, and 11 %, respectively). Patients with primary failure and intolerance to the first anti-TNF and severe disease were associated with worse clinical response. Primary non-response to prior anti-TNF treatment and severe disease were predictive of poorer clinical remission. Low levels of C-reactive protein (CRP) and faecal calprotectin (FC) at baseline were predictors of clinical remission.

CONCLUSIONS

In clinical practice, ADA was effective in UC, especially in anti-TNF naïve patients. FC and CRP could be predictors of treatment effectiveness.

Utility of Biomarkers in the Management of Inflammatory Bowel Disease

OPINION STATEMENT

Inflammatory bowel disease (IBD) is comprised of complex clinical and pathological conditions. It runs a chronic course, and proper management requires constant monitoring of disease activity. Recent evidence suggests that subjective patient scores have a poor correlation with disease activity. Endoscopy remains the gold standard for diagnosing and monitoring disease activity. As healthcare is moving towards less costly and less invasive treatments, the need for biomarkers in the management of IBD is evident. Over the last decade, several biomarkers have been found, which may correct the discrepancy between subjective patient scores and the need for endoscopy.

Fecal HMGB1 Reveals Microscopic Inflammation in Adult and Pediatric Patients with Inflammatory Bowel Disease in Clinical and Endoscopic Remission

BACKGROUND

Fecal high mobility group box 1 (HMGB1) has been suggested to be a novel noninvasive biomarker of gut inflammation. We aimed to assess the reliability of fecal HMGB1, compared with fecal calprotectin (FC), in detecting intestinal inflammation in pediatric and adult patients with inflammatory bowel disease (IBD) and to evaluate the accuracy of HMGB1 in identifying patients with IBD in clinical and endoscopic remission who still have histologic features of inflammation.

METHODS

Stool samples from 85 children with IBD (49 Crohn's disease [CD] and 36 ulcerative colitis [UC] and 119 adults [57 Crohn's disease and 62 ulcerative colitis]) were analyzed for the study. Age-matched healthy subjects were used as controls. Fecal HMGB1 and fecal calprotectin were detected through western blot and ELISA, respectively.

RESULTS

Fecal HMGB1 expression was significantly increased in pediatric and adult patients with Crohn's disease and ulcerative colitis and strongly correlated with the disease severity. Fecal calprotectin and HMGB1 significantly correlated in pediatric (r: 0.60, P < 0.001) and adult (r: 0.72, P < 0.001) IBD patients. Moreover, in patients with clinical and endoscopic remission only fecal HMGB1 showed a strong match with the degree of histological scores of inflammation (CGHAS/IGHAS for Crohn's disease and Geboes Score for ulcerative colitis).

CONCLUSIONS

Fecal HMGB1 is confirmed to be a reliable biomarker of intestinal inflammation; indeed, it significantly correlates with fecal calprotectin in pediatric and adult IBD patients. Moreover, only fecal HMGB1 identifies histologic inflammation in subjects with IBD in clinical and endoscopic remission.

Noninvasive Testing for Mucosal Inflammation in Inflammatory Bowel Disease

Biomarkers have gained increasing attention for the diagnosis and follow-up of inflammatory bowel disease (IBD). Endoscopy remains the gold standard for assessing disease activity. Biomarkers are rapid, inexpensive, and noninvasive, and can be used in different stages of the disease with high sensitivity and specificity. Calprotectin and tests for C-reactive protein are used to assess the disease activity, predict relapse, and monitor treatment response. New noninvasive tests are being studied. This review discusses current evidence for these surrogate markers, their potential clinical applications, and limitations in disease management. We highlight recent advances in IBD biomarkers and future uses.