Comparison of non-invasive biomarkers faecal BAFF, calprotectin and FOBT in discriminating IBS from IBD and evaluation of intestinal inflammation

Toxigenic Clostridium perfringens Isolated from At-Risk Paediatric Inflammatory Bowel Disease Patients

BACKGROUND AND AIMS

This study aimed to identify microbial drivers of inflammatory bowel disease [IBD], by investigating mucosal-associated bacteria and their detrimental products in IBD patients.

METHODS

We directly cultured bacterial communities from mucosal biopsies from paediatric gastrointestinal patients and examined for pathogenicity-associated traits. Upon identifying Clostridium perfringens as toxigenic bacteria present in mucosal biopsies, we isolated strains and further characterized toxicity and prevalence.

RESULTS

Mucosal biopsy microbial composition differed from corresponding stool samples. C. perfringens was present in eight of nine patients' mucosal biopsies, correlating with haemolytic activity, but was not present in all corresponding stool samples. Large IBD datasets showed higher C. perfringens prevalence in stool samples of IBD adults [18.7-27.1%] versus healthy controls [5.1%]. In vitro, C. perfringens supernatants were toxic to cell types beneath the intestinal epithelial barrier, including endothelial cells, neuroblasts, and neutrophils, while the impact on epithelial cells was less pronounced, suggesting C. perfringens may be particularly damaging when barrier integrity is compromised. Further characterization using purified toxins and genetic insertion mutants confirmed perfringolysin O [PFO] toxin was sufficient for toxicity. Toxin RNA signatures were found in the original patient biopsies by PCR, suggesting intestinal production. C. perfringens supernatants also induced activation of neuroblast and dorsal root ganglion neurons in vitro, suggesting C. perfringens in inflamed mucosal tissue may directly contribute to abdominal pain, a frequent IBD symptom.

CONCLUSIONS

Gastrointestinal carriage of certain toxigenic C. perfringens may have an important pathogenic impact on IBD patients. These findings support routine monitoring of C. perfringens and PFO toxins and potential treatment in patients.

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.

[Research advances on B-cell activating factor and its targeted agents in inflammatory bowel disease]

B-cell activating factor (BAFF), a critical regulator of B cells, is involved in various autoimmune diseases. Inflammatory bowel disease (IBD) is a group of chronic and recurrent intestinal inflammatory disorders with unclear etiology, and its global incidence has been increasing in recent years. Abnormal immune responses triggered by multiple factors are closely related to the pathogenesis of IBD. Previous studies have confirmed the association of B-cell abnormal activation and increased production of autoantibodies with the development of ulcerative colitis. However, the involvement of BAFF in the mechanisms of IBD remains unclear. This review summarizes the potential role of BAFF in the pathogenesis of IBD and provides an overview of targeted therapies on BAFF in IBD, aiming to contribute insights for targeted treatments of IBD.

Systematic review with meta-analysis: Diagnostic performance of faecal calprotectin in distinguishing inflammatory bowel disease from irritable bowel syndrome in adults

BACKGROUND

Symptoms of inflammatory bowel disease (IBD) often overlap with those of irritable bowel syndrome (IBS).

AIM

To evaluate the diagnostic performance of faecal calprotectin in distinguishing patients with IBD from those with IBS METHODS: We searched MEDLINE, Embase, Scopus, and Cochrane Library databases up to 1 January 2023. Studies were included if they assessed the diagnostic performance of faecal calprotectin in distinguishing IBD from IBS (defined according to the Rome criteria) using colonoscopy with histology or radiology as reference standard in adults. We calculated summary sensitivity and specificity and their 95% confidence intervals (CI) using a random-effect bivariate model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies II.

RESULTS

We included 17 studies with a total of 1956 patients. The summary sensitivity was 85.8% (95% CI: 78.3-91), and the specificity was 91.7% (95% CI: 84.5-95.7). At a prevalence of IBD of 1%, the negative predictive value was 99.8%, while the positive predictive value was only 9%. Subgroup analyses showed a higher sensitivity in Western than in Eastern countries (88% vs 73%) and at a cut-off of ≤50 μg/g than at >50 μg/g (87% vs. 79%), with similar estimates of specificity. All studies were at "high" or "unclear" risk of bias.

CONCLUSIONS

Faecal calprotectin is a reliable test in distinguishing patients with IBD from those with IBS. Faecal calprotectin seems to have a better sensitivity in Western countries and at a cut-off of ≤50 μg/g.

Human gut microbiome and metabolite dynamics under simulated microgravity

The Artificial Gravity Bed Rest - European Space Agency (AGBRESA) study was the first joint bed rest study by ESA, DLR, and NASA that examined the effect of simulated weightlessness on the human body and assessed the potential benefits of artificial gravity as a countermeasure in an analog of long-duration spaceflight. In this study, we investigated the impact of simulated microgravity on the gut microbiome of 12 participants during a 60-day head-down tilt bed rest at the :envihab facilities. Over 60 days of simulated microgravity resulted in a mild change in the gut microbiome, with distinct microbial patterns and pathway expression in the feces of the countermeasure group compared to the microgravity simulation-only group. Additionally, we found that the countermeasure protocols selectively increased the abundance of beneficial short-chain fatty acids in the gut, such as acetate, butyrate, and propionate. Some physiological signatures also included the modulation of taxa reported to be either beneficial or opportunistic, indicating a mild adaptation in the microbiome network balance. Our results suggest that monitoring the gut microbial catalog along with pathway clustering and metabolite profiling is an informative synergistic strategy to determine health disturbances and the outcome of countermeasure protocols for future space missions.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

Serum Calprotectin and B-cell activating factor are potential biomarkers for Helicobacter pylori infection

Humans always mount a robust immune response to the bacterial infection caused by Helicobacter pylori, which causes various gastrointestinal tract infections. Calprotectin (CALP) and B-Cell Activating Factor (BAFF) are inflammatory biomarkers having a role in the gastrointestinal neutrophilic response to bacterial infection. The study was designed to assess serum CALP and BAFF as inflammatory biomarkers in H. pylori infection and peptic ulcer patients. The current study comprised 112 people, including 62 H. pylori-infected patients (34 men and 28 women) who were clinically diagnosed with H. pylori infection via testing positive for the H. pylori stool antigen test; they were compared to a control group of 50 healthy people (34 men and 16 women) who were age and gender-matched to H. pylori-infected patients. The serum level of CALP and BAFF were assayed using the ELISA technique. The biochemical parameters were statistically compared between patients and controls by unpaired Man-Whitney U t-test and Receiver Operating Characteristic (ROC) curve analysis. There was a significant elevation of serum CALP in H. pylori-infected patients [116.4(120.7), p=0.0132] in comparison to healthy controls [99.50(115.8)]. Similarly, there was a significant elevation of serum BAFF concentration in H. pylori-infected patients [485.7(367.1), p=0.0014] in comparison to healthy controls [444.5(513.0)]. The ROC curve analysis suggests serum CALP and BAFF as reasonable inflammatory biomarkers for H. pylori infection with statistically significant (p=0.0135, p=0.0015) area under the ROC curve of (0.6361, 0.6748), respectively. CALP and BAFF are potent inflammatory biomarkers involved in the development and etiology of H. pylori infection. Serum CALP and BAFF levels could be used as biomarkers for chronic inflammation induced by H. pylori. CALP and BAFF biomarkers can be combined to diagnose and predict the prognosis of H. pylori infection.

Role of B-Cell Activating Factor (BAFF) in Inflammatory Bowel Disease

As early commencement of inflammatory bowel disease (IBD) treatment has been shown to substantially improve outcomes, it is of utmost importance to make a timely diagnosis of this disease. Despite undisputed sensitivity of fecal calprotectin, the most widely accepted IBD biomarker, in discriminating between irritable bowel syndrome (IBS) and IBD, as well as recognized role in monitoring disease activity and response to therapy, perhaps the biggest setback of calprotectin use in IBD is lack of specificity. Therefore, an additional biomarker in IBD is warranted. B-cell activating factor (BAFF), a member of the tumor necrosis factor (TNF) superfamily, recently emerged as a viable candidate for this role. So far, overproduction of BAFF has been observed in various autoimmune diseases, most notably in systemic lupus erythematosus, where BAFF-inhibitor belimumab was approved for treatment. As BAFF levels were also shown to correlate with indices of IBD, in this review we aimed to summarize the current evidence with respect to the role of BAFF in diagnosis and assessing the activity of IBD, as well as putative therapeutic implications that may arise from exploring of this relation.

Current noninvasive modalities in Crohn's disease monitoring

Crohn’s disease (CD) is characterized by a remitting and relapsing course. Longstanding active CD may result in accumulating intestinal damage and disease-related complications. In contrast, mucosal healing is associated with significant improvement in the health-related quality of life, longer periods of disease remission and lower risk of disease progression, complications, hospitalizations, intestinal surgeries, as well as a lower risk of developing colorectal cancer. Mucosal healing, the new treatment endpoint in CD, made necessary the development of noninvasive, accurate, objective and reliable tools for the evaluation of CD activity. Ileocolonoscopy with biopsies remains the reference standard method for the evaluation of the colonic and terminal ileal mucosa. However, it is an invasive procedure with a low risk of complications, allowing the investigation of only a small part of the small bowel mucosa without being able to assess transmural inflammation. These disadvantages limit its role in the frequent follow up of CD patients. In this review, we present the currently available biomarkers and imaging modalities for the noninvasive assessment of CD activity.

Antimicrobial peptides and the gut microbiome in inflammatory bowel disease

Antimicrobial peptides (AMP) are highly diverse and dynamic molecules that are expressed by specific intestinal epithelial cells, Paneth cells, as well as immune cells in the gastrointestinal (GI) tract. They play critical roles in maintaining tolerance to gut microbiota and protecting against enteric infections. Given that disruptions in tolerance to commensal microbiota and loss of barrier function play major roles in the pathogenesis of inflammatory bowel disease (IBD) and converge on the function of AMP, the significance of AMP as potential biomarkers and novel therapeutic targets in IBD have been increasingly recognized in recent years. In this frontier article, we discuss the function and mechanisms of AMP in the GI tract, examine the interaction of AMP with the gut microbiome, explore the role of AMP in the pathogenesis of IBD, and review translational applications of AMP in patients with IBD.

Patients With Microscopic Colitis Have Altered Levels of Inhibitory and Stimulatory Biomarkers in Colon Biopsies and Sera Compared to Non-inflamed Controls

Introduction: Microscopic colitis (MC) is an inflammatory bowel condition with two subtypes, lymphocytic colitis (LC) and collagenous colitis (CC). Unlike patients with ulcerative colitis (UC) and non-inflamed individuals, MC patients have reduced risk of developing colorectal cancer, possibly due to increased immune surveillance in MC patients.

Aim: To examine differences in levels of immunomodulatory molecules, including those involved in immune checkpoint mechanisms, in sera from patients with MC and in colonic biopsies from patients with MC and UC compared with controls.

Methods: Using Luminex, 23 analytes (4-1BB, 4-1BBL, APRIL, BAFF, BTLA, CD27, CD28, CD80, CTLA-4, E-cadherin, Galectin-3, GITR, HVEM, IDO, IL-2Rα, LAG-3, MICA, MICB, PD-1, PD-L1, PD-L2, sCD40L and TIM-3) were studied in serum from patients with active MC (n = 35) and controls (n = 23), and in colonic biopsies from patients with active LC (n = 9), active CC (n = 16) and MC in histological remission (LC n = 6, CC n = 6), active UC (n = 15) and UC in remission (n = 12) and controls (n = 58).

Results: In serum, IDO, PD-1, TIM-3, 4-1BB, CD27, and CD80 were decreased whereas 4-1BBL and IL-2Rα were increased in MC patients compared with controls. In contrast, in biopsies, levels of PD-L2 and 4-1BB were increased in MC and UC patients with active disease. Furthermore, in biopsies from CC and UC but not LC patients with active disease, CTLA-4, PD-1, APRIL, BAFF, and IL-2Rα were increased compared with controls. PD-L1 was increased in CC but not UC or LC patients. CD27 and TIM-3 were decreased in biopsies from MC patients in comparison to controls whereas levels of MICB were decreased in patients with active UC compared with controls.

Conclusions: Compared with non-inflamed controls, levels of soluble and membrane-bound immunomodulatory molecules were systemically and locally altered in MC and UC patients, with most analytes being decreased in serum but enhanced in colonic biopsies. These findings contribute to knowledge about checkpoint molecules and their role as biomarkers in MC and may also contribute to knowledge about possible mechanisms behind the seemingly protective effects of MC against colorectal cancer.

B cell-activating factor (BAFF) in children with inflammatory bowel disease

BACKGROUND

Assessing the inflammation is important in the follow-up of paediatric patients with inflammatory bowel disease (IBD). We aim to evaluate the value of B cell-activating factor (BAFF) in paediatric IBD as a potential biomarker for follow-up.

METHOD

We determined BAFF in serum and faeces and faecal calprotectin (CP) in 32 IBD children-16 Crohn's disease (CD) and 16 ulcerative colitis (UC). Twenty-six healthy children and 10 children with irritable bowel syndrome (IBS) were included as controls.

RESULTS

No differences were found in serum BAFF between IBD, IBS, and healthy group: 1037.35, 990.9 and 979.8 pg/ml, respectively, all p > 0.05, but faecal BAFF was higher in the IBD group: 15.1, 8.5 and 8.2 pg/ml, respectively, p < 0.05, and higher in the UC group (55.975 pg/ml) compared to the CD group (10.95 pg/ml), p = 0.015. Splitting the IBD group in relation to the CP level, the serum BAFF had no significantly different values between the subgroups, but the faecal BAFF was significantly higher in the >250 μg/g subgroup. Cut-off values of BAFF were calculated.

CONCLUSION

Faecal BAFF is a promising marker for monitoring the children with IBD, higher levels of BAFF being correlated with high CP.

IMPACT

Faecal BAFF is a promising marker in monitoring the children with IBD, higher levels of BAFF being correlated with high faecal calprotectin. To our knowledge, this is the first paediatric study concerning BAFF evaluation in IBD. Faecal BAFF levels could be considered a potential non-invasive marker in monitoring IBD activity in paediatric population with clinically mild or inactive disease.

A Novel Insight Into Fecal Occult Blood Test for the Management of Gastric Cancer: Complication, Survival, and Chemotherapy Benefit After R0 Resection

Background

Previous studies have shown that the all-cause mortality and non-colorectal cancer mortality of patients with fecal occult blood test (FOBT) positivity are significantly increased, implying that FOBT results may have more prognostic value.

Methods

Retrospective analysis was performed for gastric cancer (GC) patients who underwent R0 gastrectomy from July 2007 to July 2014 at our hospital. Propensity score matching (PSM) was used to reduce confounding bias and a computerized technique for the nearest available score matching without replacement was applied. The cumulative survival rate was calculated using the Kaplan-Meier method and a log-rank test. Cox proportional hazards regression and logistic regression was used to determine the independent prognostic factors associated with survival and postoperative complications, respectively. The expression level of tumor-associated macrophages (TAMs) and proinflammatory cytokines (TNF-α, IL-6) were evaluated by immunohistochemical (IHC).

Results

A total of 3,003 patients were included and 246 patients (8.2%) were in preoperative FOBT positive status. There was no significant difference in demographic data between preoperative FOBT positive and negative group after a 1:4 PSM. The overall postoperative complications, major complications, and anastomotic leakage were significantly higher in the preoperative FOBT-positive group than in the preoperative FOBT-negative group. Moreover, preoperative FOBT-positivity was an independent risk factor for 5-year overall survival (OS) (HR: 1.32, p = 0.005). For stage II/III patients, the postoperative adjuvant chemotherapy (PAC) benefit was found in preoperative FOBT-negative group (5-year OS: 49.9 vs. 36.8%, p = 0.001), whereas the PAC benefit was lost in preoperative FOBT-positive groups (5-year OS: 40.8 vs. 37.7% p = 0.896). Finally, IHC found that preoperative FOBT-positivity in patients was significantly associated with higher TAMs infiltration and higher expression of IL-6 and TNF-α in tumor tissues than in the preoperative FOBT-negative group.

Conclusion

As a simple and low-cost method, preoperative FOBT results can predict both complications and survival after R0 gastrectomy for GC. More importantly, stage II/III GC patients with FOBT-positive seem not benefit from PAC alone. Further exploration is warranted.

Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD): An observational study in Mexico

Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD. Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test. Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn's disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments. Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD.

Patient knowledge of fecal calprotectin in inflammatory bowel disease (IBD): An observational study in Mexico

Background: Fecal calprotectin (FC) can be a valuable tool to optimize health care for patients with inflammatory bowel disease (IBD). The objective of this observational study was to determine the level of knowledge of the FC test in Mexican patients with IBD. Methods: A self-report questionnaire was distributed via Facebook to patients with IBD. The survey consisted of 15 questions in two categories: the first category assessed knowledge of IBD diagnosis, and the second category assessed knowledge of the FC test. Results: In total, 460 patients with IBD participated, of which 83.9% (386) had ulcerative colitis (UC) and 16.0% (74) had Crohn's disease (CD). Regarding IBD diagnosis, 41.9% of participants stated that they did not know of a non-invasive test for fecal matter to identify inflammation of the colon. Regarding the FC test, 57.5% (UC) and 58.1% (CD) stated that they did not know about the test. Additionally, 65.8% (UC) and 51.3% (CD) of participants stated that they had never received the FC test and 82.6% (UC) and 77.0% (CD) recognized that the FC test was difficult to access in their medical practice. Furthermore, 66% (UC) and 52.7% (CD) of participants noted that their specialist doctor had never suggested the FC test to them, yet 89.1% (UC) and 87.8% (CD) stated that they would prefer FC analysis for their IBD follow-up assessments. Conclusions: There is little knowledge of the FC biomarker among Mexican patients with IBD. This suggests the need for greater dissemination of its use and scope as a biomarker in IBD.

Diagnostic value of fecal B cell activating factor in patients with abdominal discomfort

Fecal calprotectin has successfully been widely recommended as a sensitive biomarker of inflammatory bowel diseases (IBD). Recently, we have identified an excellent new fecal biomarker, B cell activating factor (BAFF), as being as effective as fecal calprotectin for diagnosing intestinal inflammation. In this study, a total of 230 patients with abdominal discomfort were prospectively enrolled and fecal samples were collected within 24 h before the endoscopic examinations. We show that fecal BAFF levels were significantly higher in patients with ulcerative colitis (median = 1549 pg/g, P < 0·0001), Crohn's disease (median = 735 pg/g, P < 0·0001), gastric cancer (median = 267 pg/g, P < 0·0001) and colorectal cancer (median = 533 pg/g, P < 0·0001) than those in healthy groups (median = 61 pg/g), while the values of which in patients with gastric polyps, colorectal polyps, esophagitis/gastritis/duodenitis and peptic ulcer were in the range of healthy individuals (P > 0·05). An optimal cut-off value at 219·5 pg/g of fecal BAFF produced sensitivity, specificity, positive predictive and negative predictive values of 85, 91, 84 and 92%, respectively, for IBD or carcinoma. Our results therefore indicate a potential role for fecal BAFF as a sensitive screening parameter for IBD and gastrointestinal carcinoma, as well a useful tool to select patients with abdominal discomfort for further endoscopic examinations.

Novel potential biomarkers for the diagnosis and monitoring of patients with ulcerative colitis

Unambiguously, great progress has been achieved in the unraveling of more pathological pathways implicated in the development and progression of ulcerative colitis during the last decades. Novel effective drugs that have augmented the management armamentarium have been developed alongside this growing comprehension of the disease, rendering mucosal healing not only a feasible but the optimal goal of every therapy. Clinical evaluation, colonoscopy and biomarkers are the tools used by practitioners for the diagnosis and assessment of the status of the disease in order to achieve clinical remission and mucosal healing for their patients. Among these tools, colonoscopy is the gold method for the cause but is still an invasive, high-cost procedure with possible adverse events such as perforation. While clinical evaluation entails much subjectivity, biomarkers are objective, easily reproducible, non-invasive, cheap and potent surrogate tools of mucosal inflammation. Unfortunately, the well-established, currently in use serum biomarkers, such as C-reactive protein, erythrocyte sedimentation rate and others, do not display sufficiently acceptable sensitivity and specificity rates for the diagnosis of ulcerative colitis and, most importantly, do not represent precisely the mucosal inflammation status of the disease. Therefore, the discovery of new serum biomarkers has been the cause of several studies attempting to discover an "optimal" serum biomarker during the recent years. After thorough research, collection and examination of current data, this review focuses on and selectively presents promising, potential, novel serum biomarkers of ulcerative colitis as they are indicated by studies on the patient over the last years.

Gastrointestinal motility and absorptive disorders in patients with inflammatory bowel diseases: Prevalence, diagnosis and treatment

Inflammatory bowel diseases (IBD), Crohn`s disease and ulcerative colitis, are chronic conditions associated with high morbidity and healthcare costs. The natural history of IBD is variable and marked by alternating periods of flare and remission. Even though the use of newer therapeutic targets has been associated with higher rates of mucosal healing, a great proportion of IBD patients remain symptomatic despite effective control of inflammation. These symptoms may include but not limited to abdominal pain, dyspepsia, diarrhea, urgency, fecal incontinence, constipation or bloating. In this setting, commonly there is an overlap with gastrointestinal (GI) motility and absorptive disorders. Early recognition of these conditions greatly improves patient care and may decrease the risk of mistreatment. Therefore, in this review we describe the prevalence, diagnosis and treatment of GI motility and absorptive disorders that commonly affect patients with IBD.

Paradoxical role of Breg-inducing cytokines in autoimmune diseases

Regulatory B cells (Breg) are crucial immunoregulators that maintain peripheral tolerance and suppress inflammatory autoimmune responses. In recent years, our understanding on the nature and mechanism of action of Bregs has revealed the important role of cytokines in promoting the regulatory properties of this unique B cell subset, both in animal and human models. In this review, we compiled the cytokines that have been reported by multiple studies to induce the expansion of Breg. The Breg-inducing cytokines which are currently known include IL-21, IL-6, IL1β, IFNα, IL-33, IL-35, BAFF and APRIL. As cytokines are also known to play a pivotal role in the pathogenesis of autoimmune diseases, in parallel we reviewed the pattern of expression of the Breg-inducing cytokines in Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA), Inflammatory Bowel Diseases (IBD) and Multiple Sclerosis (MS). We show here that Breg-inducing cytokines are commonly implicated in these inflammatory diseases where they typically have a higher expression than in healthy individuals, suggesting their paradoxical nature. Interestingly, despite the general overexpression of Breg-inducing cytokines, it is known that Breg cells are often numerically or functionally impaired in various autoimmune conditions. Considering these alterations, we explored the possible parameters that may influence the function of Breg-inducing cytokines in exhibiting either their regulatory or pro-inflammatory properties in the context of autoimmune conditions.

Self-reactive B cells in the GALT are actively curtailed to prevent gut inflammation

Immune homeostasis in the gut associated lymphoid tissues (GALT) is critical to prevent the development of inadvertent pathologies. B cells as the producers of antibodies and cytokines plays an important role in maintaining the GALT homeostasis. However, the mechanism by which B cells specifically direct their responses towards non-self-antigens and become ignorant to self-antigens in the GALT is not known. Therefore, we developed a novel mouse model by expressing Duck Egg Lysozyme (DEL) in gut epithelial cells in presence of HEL reactive B cells. Notably, we observed a transient activation and rapid deletion of self-reactive B cells in Peyers Patches and Mesenteric lymph nodes upon self-antigen exposure. The survival of self-reactive B cells upon exposure to their self-antigen was partially rescued by blocking receptor editing but could be completely rescued by stronger survival signal like ectopic expression of BCL2. Importantly, rescuing the self-reactive B cells promoted production of auto-antibodies and gut inflammation. Mechanistically, we identify a specific activation of TGFβ signaling in self-reactive B cells in the gut and a critical role of this pathway in maintaining peripheral tolerance. Collectively, our studies describe functional consequences and fate of self-reactive B cells in GALT and provide novel mechanistic insights governing self-tolerance of B cells in the gut.

Galectin-3 Regulates Indoleamine-2,3-dioxygenase-Dependent Cross-Talk between Colon-Infiltrating Dendritic Cells and T Regulatory Cells and May Represent a Valuable Biomarker for Monitoring the Progression of Ulcerative Colitis

Galectin-3 regulates numerous biological processes in the gut. We investigated molecular mechanisms responsible for the Galectin-3-dependent regulation of colon inflammation and evaluated whether Galectin-3 may be used as biomarker for monitoring the progression of ulcerative colitis (UC). The differences in disease progression between dextran sodium sulphate-treated wild type and Galectin-3-deficient mice were investigated and confirmed in clinical settings, in 65 patients suffering from mild, moderate, and severe colitis. During the induction phase of colitis, Galectin-3 promoted interleukin-1β-induced polarization of colonic macrophages towards inflammatory phenotype. In the recovery phase of colitis, Galectin-3 was required for the immunosuppressive function of regulatory dendritic cells (DCs). Regulatory DCs in Galectin-3:Toll-like receptor-4:Kynurenine-dependent manner promoted the expansion of colon-infiltrated T regulatory cells (Tregs) and suppressed Th1 and Th17 cell-driven colon inflammation. Concentration of Galectin-3 in serum and stool samples of UC patients negatively correlated with clinical, endoscopic, and histological parameters of colitis. The cutoff serum values of Galectin-3 that allowed the discrimination of mild from moderate and moderate from severe colitis were 954 pg/mL and 580 pg/mL, respectively. Fecal levels of Galectin-3 higher than 553.44 pg/mL indicated attenuation of UC. In summing up, Galectin-3 regulates the cross-talk between colon-infiltrating DCs and Tregs and represents a new biomarker for monitoring the progression of UC.

Improved monitoring of inflammatory activity in patients with ulcerative colitis by combination of faecal tests for haemoglobin and calprotectin

Faecal calprotectin (FC) tests and faecal immunological tests (FIT) for haemoglobin have been used to monitor disease activity in patients with ulcerative colitis (UC) but used alone they have some limitation concerning the predictive ability. We aimed to test if an FC test used in combination with FIT could improve the predictive ability. Consecutive out-patients with UC (n = 93) who were admitted for colonoscopy completed a single faecal sample before the start of bowel preparation. A quantitative CALPRO^® calprotectin ELISA test and a qualitative FIT (cut-off < 40 ng/mL) were analyzed. An estimated Mayo score and a score of histological inflammation was performed blinded to the result of the faecal tests. The sensitivity, specificity, negative predictive value and positive predictive value for endoscopic inflammation (Mayo score > 1) was for FIT 85%, 83%, 96%, 57% and for FC > 186 µg/g 73%, 87%, 87%, 54%. Corresponding results for FIT*FC > 186 µg/g (at least one test positive) were 92%, 69%, 97%, 43%. For detecting moderate/severe histological inflammation the results were for FIT 69%, 79%, 92%, 43%, for FC > 75 µg/g 95%, 62%, 98%, 41%, and for FIT*FC > 75 µg/g 100%, 60%, 100%, 36%. None of the markers alone or in combination were useful to predict deep remission (Mayo score = 0 and no histological inflammation). We conclude that using the combination of an FC test and FIT shows minor improvement in predictive ability for inflammatory activity and remission in patients with UC.

Overlapping irritable bowel syndrome and inflammatory bowel disease

The pathogenesis of irritable bowel-type symptoms occurring in patients with inflammatory bowel disease who are in apparent remission continues to generate scientific controversy and the interpretation and management of these symptoms, so distressing to the sufferer, represent major challenges for the clinician. On the one hand, these symptoms often satisfy Rome IV criteria for IBS and their occurrence correlates highly with anxiety, a known trigger for IBS. On the other hand, recent studies have shown that many of these patients exhibit subtle inflammatory changes. These observations beg the question: are these symptoms "true" IBS superimposed on IBD, or an active but subclinical form of IBD? While it is certain that earlier studies failed to detect subclinical inflammation, it is also evident that even with the use of sensitive biomarkers for inflammation, such as calprotectin and lactoferrin backed up by pan-endoscopy and biopsy to exclude ongoing inflammatory activity in its most subtle form, the prevalence of IBS-type symptoms remains higher than expected in the IBD patient. Pending further definition of its etiology and pathology, we coined the term irritable inflammatory bowel syndrome (IIBS) to refer to this phenomenon. Here we explore the risk factors for this entity, sift through clues to its pathogenesis and attempt to provide, albeit bereft of a robust evidence base, an approach to its management.

Excluding inflammatory bowel disease in the irritable bowel syndrome patient: how far to go?

PURPOSE OF REVIEW

Irritable bowel syndrome (IBS) is among the most commonly encountered conditions in primary care and gastroenterology. There is ample evidence that an IBS diagnosis based on symptom-based criteria and exclusion of alarm features that would otherwise support diagnostic testing is accurate and durable. For many clinicians, however, IBS remains a diagnosis of exclusion because of concern surrounding missed diagnoses of inflammatory bowel disease (IBD) or other organic gastrointestinal diseases. Using blood and/or fecal biomarker tests to shift the precolonoscopy probability of IBD in patients with symptoms mimicking IBS is becoming an increasingly reasonable practice with improvement in 'preliminary' tests.

RECENT FINDINGS

Fecal calprotectin (FCP) testing appears to be the most sensitive preliminary test for discriminating IBD from IBS. Although both fecal lactoferrin and FCP were superior to serum C-reactive peptide (CRP) in their diagnostic accuracy, FCP is superior to fecal lactoferrin based on available literature.

SUMMARY

In patients with IBS with diarrhea who have not undergone previous extensive evaluation, the ability of screening tests to detect colonic inflammation is improving. FCP and fecal lactoferrin are reliable predictors of colonic inflammation and should be considered for standard testing in patients with IBS-D symptoms to help identify those who would benefit most from colonoscopy. Although predictive, there currently are no fecal or serum tests that can definitively identify or subtype IBD.

From bench to bedside: Fecal calprotectin in inflammatory bowel diseases clinical setting

Fecal calprotectin (FC) has emerged as one of the most useful tools for clinical management of inflammatory bowel diseases (IBD). Many different methods of assessment have been developed and different cut-offs have been suggested for different clinical settings. We carried out a comprehensive literature review of the most relevant FC-related topics: the role of FC in discriminating between IBD and irritable bowel syndrome (IBS) and its use in managing IBD patients In patients with intestinal symptoms, due to the high negative predictive value a normal FC level reliably rules out active IBD. In IBD patients a correlation with both mucosal healing and histology was found, and there is increasing evidence that FC assessment can be helpful in monitoring disease activity and response to therapy as well as in predicting relapse, post-operative recurrence or pouchitis. Recently, its use in the context of a treat-to-target approach led to a better outcome than clinically-based therapy adjustment in patients with early Crohn’s disease. In conclusion, FC measurement represents a cheap, safe and reliable test, easy to perform and with a good reproducibility. The main concerns are still related to the choice of the optimal cut-off, both for differentiating IBD from IBS, and for the management of IBD patients.

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.

Reduced Transferrin Levels in Active Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an inflammatory disease of unclear etiopathogenesis and challenging diagnosis, frequently complicated by anemia and malnutrition. C-reactive protein (CRP) remains the only biochemical marker of clinical relevance. The aim of this study was to test hypothesis that transferrin, coinfluenced by inflammation, malnutrition, anemia, and oxidative stress, may better reflect global IBD patient's condition than any other more specific index. Transferrin and other indices of inflammation, anemia, malnutrition, and oxidative stress were measured in 137 IBD patients (Crohn's disease (CD): n = 63 and ulcerative colitis (UC): n = 74) and 97 controls. Transferrin is reduced in active CD and UC and negatively correlates with the disease activity scores (CD: ρ = −0.49; UC: ρ = −0.52). In UC, transferrin correlates negatively with CRP, erythrocyte sedimentation rate (ESR), leukocytes, platelets, interleukin-6, interleukin-10, and TNF-α and positively with albumins, cholesterol, hemoglobin, hematocrit, erythrocytes, iron, and paraoxonase-1. In CD, transferrin correlates negatively with CRP, leukocytes, platelets, interleukin-1, and interleukin-6 and positively with albumins, iron, catalase, glutathione peroxidase-1, superoxide dismutase-1, and paraoxonase-1. The associations with inflammation and anemia/malnutrition were more pronounced in UC and with oxidative stress in CD. As UC activity marker, transferrin outperforms ESR and hemoglobin, indices used in calculating the disease clinical severity score.

Gut biofilm forming bacteria in inflammatory bowel disease

Inflammatory bowel disease (IBD) symbolizes a group of intestinal disorders in which prolonged inflammation occur in the digestive tract (esophagus, large intestine, small intestine mouth, stomach). Both genetic and environmental factors (infections, stress, diet) are involved in the development of IBD. As we know that bacteria are found in the intestinal mucosa of human and clinical observations revealed bacterial biofilms associated with patients of IBD. Various factors and microbes are found to play an essential role in biofilm formation and mucosal colonization during IBD. Biofilm formation in the digestive tract is dependent on an extracellular matrix synthesized by the bacteria and it has an adverse effect on the immune response of the host. There is no satisfactory and safe treatment option for IBD. Therefore, the current research aims to disrupt biofilm in IBD and concentrates predominantly on improving the drug. Here, we review the literature on bacterial biofilm and IBD to gather new knowledge on the current understanding of biofilm formation in IBD, host immune deregulation and dysbiosis in IBD, molecular mechanism, bacteria involved in biofilm formation, current and future regimen. It is urgently required to plan new ways to control and eradicate bacteria in biofilms that will open up novel diagnostic and therapeutic avenues for IBD. This article includes the mechanism of signaling molecules with respect to the biofilm-related genes as well as the diagnostic methods and new technologies involved in the treatment of IBD.