Fecal markers of inflammation used as surrogate markers for treatment outcome in relapsing inflammatory bowel disease

The role of fecal biomarkers in individuals with inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and Ulcerative Colitis (UC), is a relapsing and remitting condition. Noninvasive biomarkers have an increasingly important role in the diagnosis of IBD and in the prediction of future disease course in individuals with IBD. Strategies for the management of IBD increasingly rely upon close monitoring of gastrointestinal inflammation.

AREAS COVERED

This review provides an update on the current understanding of established and novel stool-based biomarkers in the diagnosis and management of IBD. It also highlights key gaps, identifies limitations, and advantages of current markers, and examines aspects that require further study and analysis.

EXPERT OPINION

Current noninvasive inflammatory markers play an important role in the diagnosis and management of IBD; however, limitations exist. Future work is required to further characterize and validate current and novel markers of inflammation. In addition, it is essential to better understand the roles and characteristics of noninvasive markers to enable the appropriate selection to accurately determine the condition of the intestinal mucosa.

Smart Capsule for Targeted Detection of Inflammation Levels Inside the GI Tract

Effective management of Inflammatory Bowel Disease (IBD) is contingent upon frequent monitoring of inflammation levels at targeted locations within the gastrointestinal (GI) tract. This is crucial for assessing disease progression and detecting potential relapses. To address this need, a novel single-use capsule technology has been devised that enables region-specific inflammation measurement, thereby facilitating repeatable monitoring within the GI tract. The capsule integrates a pH-responsive coating for location-specific activation, a chemiluminescent paper-based myeloperoxidase (MPO) sensor for inflammation detection, and a miniaturized photodetector, complemented by embedded electronics for real-time wireless data transmission. Demonstrating linear sensitivity within the physiological MPO concentration range, the sensor is capable of effectively identifying inflammation risk in the GI fluid. Luminescence emitted by the sensor, proportional to MPO concentration, is converted into an electrical signal by the photodetector, generating a quantifiable energy output with a sensitivity of 6.14 µJ/U.ml-1. The capsule was also tested with GI fluids collected from pig models simulating various inflammation states. Despite the physiological complexities, the capsule consistently activated in the intended region and accurately detected MPO levels with less than a 5% variation between readings in GI fluid and a PBS solution. This study heralds a significant step towards minimally invasive, in situ GI inflammation monitoring, potentially revolutionizing personalized IBD management and patient-specific therapeutic strategies.

Cirsimaritin Alleviates Dextran Sodium Sulfate-Induced Acute Colitis in Experimental Animals: A Therapeutic Approach for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic disease that affects the entire digestive tract. IBD can be classified as ulcerative colitis or Crohn's disease. The key symptoms of IBD include the emergence of abscesses or pustules, pronounced abdominal discomfort, diarrhea, fistulas, and intestinal narrowing, all of which can greatly affect a patient's daily well-being. Several factors, including bacterial infections, immune response irregularities, and changes in the intestinal milieu, can contribute to the onset of IBD. The aim of this study was investigating the role of cirsimaritin in reducing the severity of colitis in animal model. To induce colitis in laboratory Swiss albino mice, a 4% dextran sulfate sodium (DSS) concoction was provided in their hydration source for a duration of six days. Before the onset of colitis, mice were treated with cirsimaritin (10 mg/kg) once daily to evaluate its potential treatment effects against DSS-induced inflammation. The results showed that 10 mg/kg of cirsimaritin decreased colitis severity (P<0.05). Moreover, cirsimaritin successfully reversed the detrimental effects induced by DSS, including weight reduction, colon truncation, tissue-related damage, increased levels of inflammatory cells in the affected region, and secretion of proinflammatory cytokines. Our findings suggest that cirsimaritin can effectively alleviate acute colitis triggered by DSS.

Preventive Anti-inflammatory Effects of Apocynin on Acetic Acid-Induced Colitis in Rats

Ulcerative colitis is an inflammatory bowel disease with a complex aetiology characterised by abnormal immune responses and oxidative stress-induced tissue injury. Inflammatory cells play an important role in the progression of this pathology through the overproduction of reactive oxygen species (ROS) from various sources including the NADPH oxidases (NOXs). The aim of this study was to investigate the preventive effect of apocynin, a natural antioxidant molecule and a selective inhibitor of NOXs, on acetic acid (AA)-induced ulcerative colitis in rats. Our results first confirmed that apocynin has a high free radical scavenging capacity as well as a potent iron chelating ability. Oral pretreatment of rats with apocynin (200 mg/kg and 400 mg/kg) for 7 days prior to AA-induced colitis suppressed the increase in pro-oxidant markers in colonic homogenates and preserved colonic cytoarchitecture from acetic acid-induced damage. Oral administration of apocynin (200 mg/kg and 400 mg/kg) also reduced several systemic inflammatory markers such as alkaline phosphatase, iron, pro-inflammatory cytokines, C-reactive protein and myeloperoxidase. This study shows that apocynin protects rats from acetic acid-induced colonic inflammation and suggests that apocynin may have a promising beneficial effect in the prevention of ulcerative colitis.

Antioxidant and anti-inflammatory protective effects of yellowtail (Seriola quinqueradiata) milt hydrolysates on human intestinal epithelial cells in vitro and dextran sodium sulphate-induced mouse colitis in vivo

Milt is an underutilized fish processing by-product containing valuable nutrients for human health. Here, a gastrointestinal hydrolysate of degreased yellowtail (Seriola quinqueradiata) milt contained 70.6% arginine-rich protein, 20% nucleic acids, 7.1% minerals and 2.3% carbohydrates. Yellowtail milt hydrolysates (YMH) effectively attenuated the H₂O₂-induced burst of intracellular reactive oxygen species, plasma membrane impairment, loss of cell viability, interleukin 8 production and the expression of claudin-4 and occludin in Caco-2 cells with its protein fraction playing a greater antioxidant role than its nucleic acid fraction. YMH also significantly counteracted the tumor necrosis factor α- and interleukin 1β-stimulated interleukin 8 production and cyclooxygenase-2 and inducible nitric oxide synthase expression in Caco-2 cells and inhibited the production of nitric oxide and proinflammatory mediators in lipopolysaccharide-stimulated RAW 264.7 cells depending on its protein fraction, rather than its nucleic acid fraction. YMH and a positive drug 5-aminosalicylic acid were intragastrically administered to C57BL/6 mice daily for 7 days during and after 4-day dextran sodium sulphate exposure. Based on clinical signs, colon histopathology and biochemical analysis of colonic tight junction proteins, mucus compositions and goblet cells, YMH ameliorated mouse colitis symptoms and intestinal epithelial barrier dysfunction more effectively than 5-aminosalicylic acid. According to myeloperoxidase activity, proinflammatory cytokines and NF-κB, YMH and 5-aminosalicylic acid exerted equivalent inhibitory effects on colonic and systemic inflammation. Overall, YMH have considerable antioxidant and anti-inflammatory efficacies to maintain gut health.

Amelioration of dextran sulfate sodium-induced colitis by autoinducer-2-deficient Lactiplantibacillus plantarum is mediated by anti-inflammatory effects and alleviation of dysbiosis of the gut microbiota

Lactic acid bacteria (LAB) attenuate dextran sulfate sodium (DSS)-induced colitis in mice by restoring gut flora homeostasis and modulating the immune response. Because synchronous behavior can be controlled by autoinducer-2 (AI-2)/LuxS-mediated quorum sensing, the Caco-2 cell model and DSS-induced model in C57BL/6 mice were used to explore the unknown effects of these communications involving AI-2 among various intestinal symbiotic species. The results of the cell viability and lactate dehydrogenase leakage assays indicated that the tested strains (the wild-type strains and AI-2-deficient mutants) were characterized by equal cytoprotection from hydrogen peroxide-induced injury independently of AI-2. The results of the assays of multiple indicators and proinflammatory cytokines characteristic for the symptoms of colitis in mice showed that oral administration of AI-2-deficient mutants for 7 days was more effective in ameliorating inflammation than the treatment with the wild-type strains. The treatment with AI-2-deficient mutants enriched potential probiotics (e.g., Lactobacillaceae) and controlled the proliferation of potentially harmful bacteria (e.g., Helicobacteraceae) to achieve the transformation of intestinal flora. These mutants regulated short-chain fatty acids and the intestinal epithelial barrier, thereby promoting the maintenance of relatively favorable intestinal homeostasis. These results demonstrated that the AI-2-deficient mutants provided a more pronounced ameliorative effect on colitis in a mouse model, suggesting that the background of the LAB effect is associated with the alterations in colonic flora induced by AI-2.

The Clinical Significance of Eosinophils in Ulcerative Colitis: A Systematic Review

BACKGROUND AND AIMS

Ulcerative colitis [UC] is characterised by an unpredictable disease course and variable response to therapy. Recent studies suggest a role for eosinophils in both pathogenesis and predicting treatment response. The goal of this study was to determine the association between eosinophils and clinical outcomes in UC.

METHODS

A systematic review of the literature from database inception to May 2021 was performed to identify all studies evaluating the relationship between eosinophils and/or eosinophil-derived proteins [EDPs] and clinical outcomes, such as disease activity, clinical relapse, severity of disease, and response to treatment.

RESULTS

A total of 55 studies were identified. Of these, 34 studies evaluated the relationship between eosinophils in colonic tissue and outcomes and 15 in blood. Eighteen studies assessed the relationship between EDPs and outcomes. In 25 of 34 studies, a positive correlation between eosinophils and/or EDPs and disease activity was reported, three studies found a negative correlation, and nine studies found no correlation. Positive correlations between eosinophils and clinical relapse were shown in four of nine studies, and with disease outcome severity in five of seven studies. Four of 15 studies showed that subjects with higher eosinophil levels had a poor response to treatment.

CONCLUSIONS

These findings suggest that higher eosinophil levels may be associated with increased disease activity and poorer clinical outcomes and response to therapy. Future studies are needed to determine whether a distinct eosinophil-rich UC phenotype exists and whether eosinophil-targeted therapy can alter the disease course.

Faecal Myeloperoxidase as a Biomarker of Endoscopic Activity in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD], consisting of Crohn's disease [CD] and ulcerative colitis [UC], is a relapsing-remitting illness. Treat-to-target IBD management strategies require monitoring of gastrointestinal inflammation. This study aimed to investigate faecal myeloperoxidase [fMPO], a neutrophil granule enzyme, as a biomarker of IBD activity.

METHODS

Prospectively recruited participants with IBD, undergoing ileocolonoscopy for disease assessment, provided biological samples and completed symptom questionnaires prior to endoscopy. fMPO, C-reactive protein [CRP], and faecal calprotectin [fCal] were compared with validated endoscopic indices [simple endoscopic score for CD and UC endoscopic index of severity]. Receiver operating characteristic [ROC] curves assessed the performance of fMPO, CRP, and fCal in predicting endoscopic disease activity. Baseline biomarkers were used to predict a composite endpoint of complicated disease at 12 months [need for escalation of biologic/immunomodulator due to relapse, steroid use, IBD-related hospitalisation, and surgery].

RESULTS

A total of 172 participants were recruited [91 female, 100 with CD]. fMPO was significantly correlated with endoscopic activity in both CD [r = 0.53, p < 0.01] and UC [r = 0.63, p < 0.01], and with fCal in all patients with IBD [r = 0.82, p < 0.01]. fMPO was effective in predicting moderate-to-severely active CD [AUROC 0.86, p < 0.01] and UC [AUROC 0.92, p < 0.01]. Individuals with a baseline fMPO > 26 µg/g were significantly more likely to reach the composite outcome at 12 months (hazard ratio [HR] 3.71, 95% confidence interval [CI] 2.07-6.64, p < 0.01).

CONCLUSIONS

Faecal myeloperoxidase is an accurate biomarker of endoscopic activity in IBD and predicted a more complicated IBD course during follow-up.

Mapping of etiologies of computed tomography-proven acute colitis: a prospective cohort study

Our objective was to describe the etiologies of acute colitis and to identify patients who require diagnostic endoscopy. Patients with symptoms of gastrointestinal infection and colonic inflammation on CT were prospectively included. Those immunosuppressed, with history of colorectal cancer or inflammatory bowel disease (IBD), were excluded. Microbiological analysis of the feces was performed using PCR assays BD-Max and FilmArray (GI panel,) and fecal cultures. Fecal calprotectin was determined. Patients with negative BD-Max underwent colonoscopy. One hundred and seventy-nine patients were included. BD-Max was positive in 93 patients (52%) and FilmArray in 108 patients (60.3%). Patients with infectious colitis (n = 103, 57.5%) were positive for Campylobacter spp. (n = 57, 55.3%), Escherichia coli spp. (n = 8, 7.8%), Clostridioides difficile (n = 23, 22.3%), Salmonella spp. (n = 9, 8.7%), viruses (n = 7, 6.8%), Shigella spp. (n = 6, 5.8%), Entamoeba histolytica (n = 2, 1.9%) and others (n = 4, 3.9%). Eighty-six patients underwent colonoscopy, which was compatible with ischemic colitis in 18 patients (10.1%) and IBD in 4 patients (2.2%). Fecal calprotectin was elevated in all patients, with a mean concentration of 1922.1 ± 2895.6 μg/g, and was the highest in patients with IBD (8511 ± 9438 μg/g, p < 0.001). After exclusion of patients with infectious etiology, a fecal calprotectin > 625 μg/g allowed identifying patients with IBD with an area under ROC curve of 85.1%. To conclude, computed tomography-proven colitis was of infectious etiology in 57.5% of patients. The main pathogens identified were Campylobacter spp. (55.3%), Clostridioides difficile (22.3%) and Salmonella spp. (8.7%). Ischemic colitis (10.1%) and IBD (2.2%) were seldom represented. No colorectal cancer was found.

Fecal Lactoferrin and Other Putative Fecal Biomarkers in Crohn's Disease: Do They Still Have a Potential Clinical Role?

INTRODUCTION

The need for noninvasive markers of disease activity is mandatory in the assessment of Crohn's disease (CD). The most widely fecal biomarker in CD, despite several limits, is fecal calprotectin. This review aims to elucidate the role, if any, of all other fecal biomarkers, as alternative tools for assessing clinical and endoscopic disease activity, and predict capsule endoscopy findings, response to therapy, disease relapse, and postoperative recurrence. These fecal biomarkers included lactoferrin, S100A12, high mobility group box 1, neopterin, polymorphonuclear neutrophil elastase, fecal hemoglobin, alpha1-antitrypsin, lysozyme, human beta-defensin-2, neutrophil gelatinase-associated lipocalin, matrix metalloproteinase-9, chitinase 3-like-1, M2-pyruvate kinase, myeloperoxidase, and eosinophil proteins.

METHODS

A systematic electronic search in the medical literature was performed up to April 2020. Seventy eligible studies were identified out of 859 citations. Data were grouped according to the assessment of clinical and endoscopic disease activity, capsule endoscopy findings, response to therapy, prediction of relapse, and postoperative recurrence.

RESULTS

The overall correlation between lactoferrin and clinical indexes is poor, while performance is good with endoscopic scores. Lactoferrin seems to represent a reasonably good surrogate marker of response to therapy and to be potentially useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence. The evaluation of the performance of all other fecal markers is limited by the lack of adequate data.

CONCLUSIONS

None of the fecal markers so far represents an acceptable alternative to calprotectin in clinical practice. Fecal lactoferrin is the only possible exception, but a more extensive investigation is still required.

Inflammatory bowel disease manifestations in spondyloarthritis: considerations for the clinician

INTRODUCTION

Spondyloarthropathies (SpA) are a group of inflammatory arthritis that can involve the spine and/or peripheral joints. Extra-articular manifestations, such as inflammatory bowel disease (IBD), are frequently observed within the clinical manifestations of SpA and are part of the SpA classification criteria. Evidence of IBD is observed in about 6-7% of SpA patients, and a silent, microscopic gut inflammation, could be present in up to 50% of patients. From a pathogenetic point of view, dysregulated microbiome and migration of T lymphocytes and other cells from gut to the joint ('gut-joint' axis) has been recognized, in the context of a common genetic background.

AREAS COVERED

The aim of this paper is to narratively review the recent evidences on the epidemiology, classification, clinical findings, pathogenesis, diagnosis, and treatment of IBD in patients with SpA and to provide advices for both rheumatologist and gastroenterologist in the management of IBD in SpA.

EXPERT OPINION

IBD manifestations in SpA frequently increase the burden of the disease and represent a clinical challenge, especially for the diagnosis, assessment, and treatment of patients affected by those conditions. New treatment strategies targeting both articular and intestinal manifestations are now available and may lead to a better outcome.

Clinical Value of Fecal Calprotectin in Predicting Mucosal Healing in Patients With Ulcerative Colitis

Aim: This study aimed to evaluate the clinical significance of fecal calprotectin (FC) in assessment of ulcerative colitis (UC) patients' endoscopic patterns and clinical manifestation.

Methods: A total of 143 UC patients who received colonoscopy and 108 controls were included. After providing stool samples, patients underwent total colonoscopy. FC was measured by an enzyme-linked immunosorbent assay (ELISA). Clinical activity was based on the Mayo score. Endoscopic findings was scored by the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Correlation analysis and receiver-operator characteristic (ROC) analysis were carried out to determine the significance of measurements.

Results: The median (interquartile range, IQR) of FC levels was 211 (43–990) μg/g in UC and 87.5 (40.50~181) μg/g in the control group. Fecal calprotectin correlated significantly with both Mayo and UCEIS scores (Spearman's r 0.670 and 0.592, P < 0.01). With a cut-off value of 164 μg/g for fecal calprotectin concentration, the area under the curve (AUC) in receiver operator characteristic analysis was 0.830, sensitivity was 85.42%, specificity was 73.68%, positive predictive value (PPV) was 62.12%, and negative predictive value (NPV) was 9.10% in predicting clinical active disease. Similarly, the power of FC to predict mucosal healing (MH) was modest. With a cut-off value of 154.5 μg/g, the AUC was 0.839, sensitivity was 72.34%, and specificity was 85.71%.

Conclusion: For evaluating the disease activity of UC, FC is a clinically relevant biomarker for both clinically active disease and MH in patients with UC. But the cut-off value still needs large and multicenter studies for confirmation.

Shigella-Specific Immune Profiles Induced after Parenteral Immunization or Oral Challenge with Either Shigella flexneri 2a or Shigella sonnei

Shigella spp. are a leading cause of diarrhea-associated global morbidity and mortality. Development and widespread implementation of an efficacious vaccine remain the best option to reduce Shigella-specific morbidity. Unfortunately, the lack of a well-defined correlate of protection for shigellosis continues to hinder vaccine development efforts. Shigella controlled human infection models (CHIM) are often used in the early stages of vaccine development to provide preliminary estimates of vaccine efficacy; however, CHIMs also provide the opportunity to conduct in-depth immune response characterizations pre- and postvaccination or pre- and postinfection. In the current study, principal-component analyses were used to examine immune response data from two recent Shigella CHIMs in order to characterize immune response profiles associated with parenteral immunization, oral challenge with Shigella flexneri 2a, or oral challenge with Shigella sonnei. Although parenteral immunization induced an immune profile characterized by robust systemic antibody responses, it also included mucosal responses. Interestingly, oral challenge with S. flexneri 2a induced a distinctively different profile compared to S. sonnei, characterized by a relatively balanced systemic and mucosal response. In contrast, S. sonnei induced robust increases in mucosal antibodies with no differences in systemic responses across shigellosis outcomes postchallenge. Furthermore, S. flexneri 2a challenge induced significantly higher levels of intestinal inflammation compared to S. sonnei, suggesting that both serotypes may also differ in how they trigger induction and activation of innate immunity. These findings could have important implications for Shigella vaccine development as protective immune mechanisms may differ across Shigella serotypes. IMPORTANCE Although immune correlates of protection have yet to be defined for shigellosis, prior studies have demonstrated that Shigella infection provides protection against reinfection in a serotype-specific manner. Therefore, it is likely that subjects with moderate to severe disease post-oral challenge would be protected from a homologous rechallenge, and investigating immune responses in these subjects may help identify immune markers associated with the development of protective immunity. This is the first study to describe distinct innate and adaptive immune profiles post-oral challenge with two different Shigella serotypes. Analyses conducted here provide essential insights into the potential of different immune mechanisms required to elicit protective immunity, depending on the Shigella serotype. Such differences could have significant impacts on vaccine design and development within the Shigella field and should be further investigated across multiple Shigella serotypes.

Anti-inflammatory property and functional substances of Lonicerae Japonicae Caulis

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicerae Japonicae Caulis, the dried stem and branch of Lonicera japonica Thunb., is a Chinese Materia Medica known as Ren Dong Teng in Chinese with long use history in the traditional Chinese medicine (TCM) prescriptions. Lonicerae Japonicae Caulis possesses heat-clearing and detoxifying functions according to the TCM theory. In recent years, a large amount of experimental and clinical studies proved good anti-inflammatory effects of some heat-clearing and detoxifying herbs. The present study aims to reveal the anti-inflammatory property and functional substances of Lonicerae Japonicae Caulis.

MATERIALS AND METHODS

For anti-inflammatory activity test, LPS-induced RAW 264.7 macrophages, DSS-induced SPF male C57BL/6J mice model, and LPS-induced SPF male ICR mice model were used in vitro and in vivo, respectively. The behavioral changes, organ damage, and the expression of inflammatory factors such as TNT-α and IL-6 mRNA expression were measured for activity evaluation. Lonicerae Japonicae Caulis samples were prepared by solvent extraction and subsequent column chromatography. The main components were identified and determined using UPLC-UV analysis as well as NMR interpretation after purification. To testify the contribution of main components for the anti-inflammatory activity, different samples were also prepared by compound-knockout strategy.

RESULTS

Ethanol extract of Lonicerae Japonicae Caulis could attenuate sickness symptoms in mice such as diarrhea, less activity, and depression. It could also alleviate multiple organ damage, and significantly inhibit the expression of pro-inflammatory factors such as TNF-α, IL-1β, IL-6 and IFN-γ in mice. Furthermore, the isochlorogenic acid-rich and biflavonoid-rich fractions and isochlorogenic acids A and C, and ochnaflavone could significantly down-regulate the mRNA expression of TNF-α and IL-6 in LPS-induced RAW 264.7 macrophages.

CONCLUSIONS

Lonicerae Japonicae Caulis possesses anti-inflammatory property. Its isochlorogenic acid-rich and biflavonoid-rich fractions do the major contribution. And their main components, isochlorogenic acids A and C, and ochnaflavone, take main responsibility for the anti-inflammatory property.

Study design, rationale and methods of the Revitalising Informal Settlements and their Environments (RISE) study: a cluster randomised controlled trial to evaluate environmental and human health impacts of a water-sensitive intervention in informal settlements in Indonesia and Fiji

INTRODUCTION

Increasing urban populations have led to the growth of informal settlements, with contaminated environments linked to poor human health through a range of interlinked pathways. Here, we describe the design and methods for the Revitalising Informal Settlements and their Environments (RISE) study, a transdisciplinary randomised trial evaluating impacts of an intervention to upgrade urban informal settlements in two Asia-Pacific countries.

METHODS AND ANALYSIS

RISE is a cluster randomised controlled trial among 12 settlements in Makassar, Indonesia, and 12 in Suva, Fiji. Six settlements in each country have been randomised to receive the intervention at the outset; the remainder will serve as controls and be offered intervention delivery after trial completion. The intervention involves a water-sensitive approach, delivering site-specific, modular, decentralised infrastructure primarily aimed at improving health by decreasing exposure to environmental faecal contamination. Consenting households within each informal settlement site have been enrolled, with longitudinal assessment to involve health and well-being surveys, and human and environmental sampling. Primary outcomes will be evaluated in children under 5 years of age and include prevalence and diversity of gastrointestinal pathogens, abundance and diversity of antimicrobial resistance (AMR) genes in gastrointestinal microorganisms and markers of gastrointestinal inflammation. Diverse secondary outcomes include changes in microbial contamination; abundance and diversity of pathogens and AMR genes in environmental samples; impacts on ecological biodiversity and microclimates; mosquito vector abundance; anthropometric assessments, nutrition markers and systemic inflammation in children; caregiver-reported and self-reported health symptoms and healthcare utilisation; and measures of individual and community psychological, emotional and economic well-being. The study aims to provide proof-of-concept evidence to inform policies on upgrading of informal settlements to improve environments and human health and well-being.

ETHICS

Study protocols have been approved by ethics boards at Monash University, Fiji National University and Hasanuddin University.

TRIAL REGISTRATION NUMBER

ACTRN12618000633280; Pre-results.

Increased IL-33 and IL-17 in Colorectal Carcinoma Patients with Severe Disease

Colorectal cancer (CRC) represents one of the most common cancers. It is frequently diagnosed at advanced stages, indicating on need for new diagnostic markers. The aim of this study was to determine systemic and fecal values of IL-17 and IL-33 in patients with CRC and the relationship with clinicopathological aspects of disease.

The blood samples and feces liquid fraction of 50 patients with CRC were analyzed. Serum and fecal levels of IL-33 and IL-17 were measured using sensitive enzyme-linked immunosorbent assay (ELISA) kits.

Fecal levels of Il-33 and IL-17 were increased in CRC patients with poor tumor tissue differentiation. Serum IL-33 and fecal IL-17 were increased in patients with presence of lung/liver metastasis or peritoneal carcinomatosis, respectively, while enhanced fecal IL-33 was detected only in patients with peritoneal carcinomatosis.

Positive correlation between IL-33 and IL-17 values in sera and feces, respectively was also observed.

We believe that increased local values of IL-33 and IL-17, reflected trough higher fecal concentration, in CRC patients with poor tumor tissue differentiation and with presence of lung/liver metastasis or peritoneal carcinomatosis may be considered as a sign of the tumor’s malignant progression and, consequently, of a poor prognosis for patients.

Proteomics-Informed Identification of Luminal Targets For In Situ Diagnosis of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic condition resulting in impaired intestinal homeostasis. Current practices for diagnosis of IBD are challenged by invasive, demanding procedures. We hypothesized that proteomics analysis could provide a powerful tool for identifying clinical biomarkers for non-invasive IBD diagnosis. Here, the global intestinal proteomes from commonly used in vitro and in vivo models of IBD were analyzed to identify apical and luminal proteins that can be targeted by orally delivered diagnostic agents. Global proteomics analysis revealed upregulated plasma membrane proteins in intestinal segments of proximal- and distal colon from dextran sulfate sodium-treated mice and also in inflamed human intestinal Caco-2 cells pretreated with pro-inflammatory agents. The upregulated colon proteins in mice were compared to the proteome of the healthy ileum, to ensure targeting of diagnostic agents to the inflamed colon. Promising target proteins for future investigations of non-invasive diagnosis of IBD were found in both systems and included Tgm2/TGM2, Icam1/ICAM1, Ceacam1/CEACAM1, and Anxa1/ANXA1. Ultimately, these findings will guide the selection of appropriate antibodies for surface functionalization of imaging agents aimed to target inflammatory biomarkers in situ.

Interdependence between Chromogranin-A, Alternatively Activated Macrophages, Tight Junction Proteins and the Epithelial Functions. A Human and In-Vivo/In-Vitro Descriptive Study

Background: Ulcerative colitis (UC) is characterized by altered chromogranin-A (CHGA), alternatively activated macrophages (M2) and intestinal epithelial cells (IECs). We previously demonstrated that CHGA is implicated in colitis progression by regulating the macrophages. Here, we investigated the interplay between CHGA, M2, tight junctions (TJ) and IECs in an inflammatory environment. Methods: Correlations between CHGA mRNA expression of and TJ proteins mRNA expressions of (Occludin [OCLN], zonula occludens-1 [ZO1], Claudin-1 [CLDN1]), epithelial associated cytokines (interleukin [IL]-8, IL-18), and collagen (COL1A2) were determined in human colonic mucosal biopsies isolated from active UC and healthy patients. Acute UC-like colitis (5% dextran sulphate sodium [DSS], five days) was induced in Chga-C57BL/6-deficient (Chga^−/−) and wild type (Chga^+/+) mice. Col1a2 TJ proteins, Il-18 mRNA expression and collagen deposition were determined in whole colonic sections. Naïve Chga^−/− and Chga^+/+ peritoneal macrophages were isolated and exposed six hours to IL-4/IL-13 (20 ng/mL) to promote M2 and generate M2-conditioned supernatant. Caco-2 epithelial cells were cultured in the presence of Chga^−/− and Chga^+/+ non- or M2-conditioned supernatant for 24 h then exposed to 5% DSS for 24 h, and their functional properties were assessed. Results: In humans, CHGA mRNA correlated positively with COL1A2, IL-8 and IL-18, and negatively with TJ proteins mRNA markers. In the experimental model, the deletion of Chga reduced IL-18 mRNA and its release, COL1A2 mRNA and colonic collagen deposition, and maintained colonic TJ proteins. Chga^−/− M2-conditioned supernatant protected caco-2 cells from DSS and oxidative stress injuries by improving caco-2 cells functions (proliferation, viability, wound healing) and by decreasing the release of IL-8 and IL-18 and by maintaining the levels of TJ proteins, and when compared with Chga^+/+ M2-conditioned supernatant. Conclusions: CHGA contributes to the development of intestinal inflammation through the regulation of M2 and epithelial cells. Targeting CHGA may lead to novel biomarkers and therapeutic strategies in UC.

The Synthetic Myeloperoxidase Inhibitor AZD3241 Ameliorates Dextran Sodium Sulfate Stimulated Experimental Colitis

Chronic inflammatory bowel disease (IBD) is a condition with multifactorial pathophysiology. To date, there is no permanent cure and the disease is primarily managed by immunosuppressive drugs; long-term use promotes serious side effects including increased risk malignancies. The current study aimed to target neutrophil-myeloperoxidase, a key contributor to the pathogenesis of IBD, through the use of AZD3241that inhibits extracellular myeloperoxidase. Experimental colitis was induced in C57BL/6 male mice by 2% dextran sodium sulfate in drinking water ad libitum over 9 days. Mice received either normal drinking water and peanut butter (control), 2% DSS in drinking water and peanut butter or 2% DSS in drinking water and AZD3241 (30 mg/kg) dispersed in peanut butter daily for 9 days. Administered AZD3241 attenuated body weight loss (10% p<0.05) and improved clinical score (9 fold p<0.05; a score comprising the time-dependent assessment of stool consistency and extent of rectal bleeding), loss of colonic crypts (p<0.001), preserved surface epithelium (p<0.001) and enhanced expression of the transcription factor Nrf-2 (regulator of antioxidants) and enhanced expression of the downstream antioxidant response element haeoxygenase-1 (HO-1) in the colon tissue. Also, the concentration of fecal hemoglobin and the myeloperoxidase specific oxidative damage biomarker 3-chlorotyrosine in the colon were significantly decreased in the presence of AZD3241. This latter result was consistent with AZD3241 inhibiting MPO activity in vitro. Overall, AZD3241 ameliorated the course and severity of experimental colitis through ameliorating MPO derived tissue damage and could be considered a potential therapeutic option, subject to further validation in chronic IBD models.

Metabonomics and the Gut Microbiome Associated With Primary Response to Anti-TNF Therapy in Crohn's Disease

BACKGROUND AND AIMS

Anti-tumour necrosis factor [anti-TNF] therapy is indicated for treatment of moderate to severe inflammatory bowel disease [IBD], but has a primary non-response rate of around 30%. We aim to use metabonomic and metataxonomic profiling to identify predictive biomarkers of anti-TNF response in Crohn's disease.

METHODS

Patients with luminal Crohn's disease, commencing anti-TNF therapy, were recruited with urine, faeces, and serum samples being collected at baseline and 3-monthly. Primary response was defined according to a combination of clinical and objective markers of inflammation. Samples were measured using three UPLC-MS assays: lipid, bile acid, and Hydrophillic Interaction Liquid Chromatography [HILIC] profiling with 16S rRNA gene sequencing of faeces.

RESULTS

Samples were collected from 76 Crohn's disease patients who were anti-TNF naïve and from 13 healthy controls. There were 11 responders, 37 non-responders, and 28 partial responders in anti-TNF-treated Crohn's patients. Histidine and cysteine were identified as biomarkers of response from polar metabolite profiling [HILIC] of serum and urine. Lipid profiling of serum and faeces found phosphocholines, ceramides, sphingomyelins, and triglycerides, and bile acid profiling identified primary bile acids to be associated with non-response to anti-TNF therapy, with higher levels of phase 2 conjugates in non-responders. Receiver operating curves for treatment response demonstrated 0.94 +/ -0.10 [faecal lipid], 0.81 +/- 0.17 [faecal bile acid], and 0.74 +/- 0.15 [serum bile acid] predictive ability for anti-TNF response in Crohn's disease.

CONCLUSIONS

This prospective, longitudinal cohort study of metabonomic and 16S rRNA gene sequencing analysis demonstrates that a range of metabolic biomarkers involving lipid, bile acid, and amino acid pathways may contribute to prediction of response to anti-TNF therapy in Crohn's disease.

PODCAST

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Fecal calprotectin: current and future perspectives for inflammatory bowel disease treatment

Fecal calprotectin has been widely studied in inflammatory bowel disease (IBD) under clinical and therapeutic settings. It showed a good correlation with clinical, endoscopic, and histologic findings. For these reasons, fecal calprotectin is currently one of the most useful tools in IBD care, both in diagnosis and in clinical management. The development of biologic drugs allowed a deeper control of disease, which sometimes reaches histological healing; this is associated with a reduced risk of relapses and complications. The management of IBD treatment is currently carried out with a treat-to-target approach, and mucosal healing is considered at present to be the optimal therapeutic target, but the future is going through histologic remission. Fecal calprotectin is probably the best marker of mucosal healing, but it is correlated also with histologic remission: moreover, it has been recently studied as a possible therapeutic target in the CALM study. We carried out a comprehensive literature review in order to evaluate the role of fecal calprotectin at present and in the future in the management of IBD therapies.

Fecal Eosinophil Cationic Protein Is a Diagnostic and Predictive Biomarker in Young Adults with Inflammatory Bowel Disease

BACKGROUND AND AIMS

Fecal biomarkers are important non-invasive markers monitoring disease activity in inflammatory bowel disease (IBD). We compared the significance of fecal eosinophil cationic protein (fECP) and fecal calprotectin (fCal).

METHODS

fECP and fCal were measured in patients with Crohn's disease (CD, n = 97), ulcerative colitis (UC, n = 53), Clostridioides difficile infection (CDI, n = 9), primary food allergy (PFA, n = 11), pollen-associated food allergy (n = 25) and non-inflammatory controls (n = 78). Results were correlated with clinical and endoscopic IBD activity scores.

RESULTS

fECP was significantly elevated in CD, UC, CDI and PFA compared to controls. fCal was significantly increased in CD, UC and CDI. fECP had lower diagnostic accuracy than fCal (area under the curve (AUC) = 0.88) in differentiating between endoscopically active and inactive patients with IBD (AUC = 0.77, ROC analysis). In contrast to fCal, fECP correlated negatively with age and levels were also elevated in clinically and endoscopically inactive patients with IBD <45 years (endoscopically inactive IBD vs controls; AUC for fECP = 0.86; AUC for fCal = 0.62). However, in those patients with low inflammatory activity (fCal <250 mg/kg), high fECP indicated the need for treatment modification or surgery (fECP <200 µg/kg = 22%; 200-600 µg/kg = 44%; >600 µg/kg = 82%) at month 48 of follow-up.

CONCLUSIONS

fECP is a diagnostic and prognostic marker in young patients with IBD in remission.

Variability of Faecal Calprotectin in Inflammatory Bowel Disease Patients: An Observational Case-control Study

BACKGROUND AND AIMS

Several factors have been reported to affect faecal calprotectin [FC] values, and significant variation in FC concentrations has been observed in inflammatory bowel disease [IBD] patients. We aimed to evaluate FC variability in IBD patients, and to assess the robustness of a single stool punch.

METHODS

This is a single-centre observational case-control study. Disease activity was assessed using endoscopic and clinical activity scores, as well as C-reactive protein levels. Stool samples were collected twice within a 1 to 6 days interval, and FC was measured on punches and homogenates by fluorometric enzyme immunocapture assay.

RESULTS

In all, 260 stool samples were collected from 120 patients. Intrastool variability was low, with an intraclass correlation coefficient for single measures between three punches from a single stool sample of 0.91, and median coefficient of variation [CV] of 17%. CV of two stool samples a few days apart [intra-individual variability] were significantly higher [p <0.01] with median CV of 36%. FC standard deviations correlated with mean FC levels either for intrastool or for intra-individual variability, with a Spearman's coefficient of rank correlation of 0.85 and 0.78, respectively [p <0.01]. Disease type, location, activity, and FC levels did not influence variability.

CONCLUSIONS

A single stool punch is reliable for FC measurement, considering that intrastool variability is low. Intra-individual variability a few days apart is significantly higher. Therefore, decision-making strategies based on single measurements should consider this variability, to determine the minimum optimal variation to be achieved, rather than a cut-off, especially in high FC levels.

Anti-inflammatory effects of eriocitrin against the dextran sulfate sodium-induced experimental colitis in murine model

Inflammatory bowel disease (IBD) is a continual ailment condition which engrosses the entire alimentary canal. The IBD can be primarily distinguished into two forms, ulcerative colitis, and Crohn's disease. The major symptoms of IBD include pustules or abscesses, severe abdominal pain, diarrhea, fistula, and stenosis, which may directly affect the patient's quality of life. A variety of mediators can stimulate the circumstances of IBD, some examples include infections by microbes such as bacteria, perturbation of the immune system and the surrounding environment of the intestines. Severe colitis was stimulated in the experimental animals through administering 4% dextran sulfate sodium (DSS) which is mixed in water ad libitum for 6 days. Eriocitrin (30 mg/kg) was then administered to the experimental animals followed by the induction of severe colitis to evaluate the therapeutic prospective of eriocitrin against the colon inflammation stimulated by DSS. In this study, eriocitrin (30 mg/kg) demonstrated significant (P < .05) attenuation activity against the DSS-stimulated severe colitis in experimental animals. Eriocitrin counteracted all of the clinical deleterious effects induced by DSS, such as body-weight loss, colon shortening, histopathological injury, accretion of infiltrated inflammatory cells at the inflamed region and the secretion of inflammatory cytokines. The results clearly showed that eriocitrin effectively attenuated DSS-induced acute colitis in experimental animals.

Prognostic significance of faecal eosinophil granule proteins in inflammatory bowel disease

Background: Non-invasive markers for predicting relapse would be a useful tool for the management of patients with inflammatory bowel disease. Eosinophil granulocytes and their granule proteins eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN) have previously been shown to reflect disease activity in Crohn's disease and ulcerative colitis.Aim: To examine the capacity of faecal ECP and EDN to predict relapse in ulcerative colitis and Crohn's disease, and to compare these proteins with faecal calprotectin.Methods: Patients with Crohn's disease (n = 49) and ulcerative colitis (n = 55) were followed prospectively until relapse or end of the two-year study period. Faecal samples were obtained every third month. The predictive value of ECP and EDN was assessed in Cox regression models.Results: In ulcerative colitis, a doubled EDN or ECP concentration was associated with a 31% and 27% increased risk of relapse, respectively. EDN levels were increased both at relapse and three months prior. By contrast, in Crohn's disease, the concentration of EDN was higher among patients in remission than in those who relapsed. Correlations between faecal calprotectin, ECP and EDN were observed in both diseases.Conclusions: We demonstrate that the risk of relapse in ulcerative colitis can be predicted by consecutively measuring faecal EDN every third month, and suggest EDN as a complementary faecal marker to calprotectin to predict future relapse in ulcerative colitis. Our finding of higher EDN in Crohn's disease-patients staying in remission than in those who relapsed indicates different functions of the protein in ulcerative colitis and Crohn's disease.

The nitroxide 4-methoxy-tempo inhibits the pathogenesis of dextran sodium sulfate-stimulated experimental colitis

Inflammatory bowel disease (IBD) is a chronic condition characterised by leukocyte recruitment to the gut mucosa. Leukocyte myeloperoxidase (MPO) produces the two-electron oxidant hypochlorous acid (HOCl), damaging tissue and playing a role in cellular recruitment, thereby exacerbating gut injury. We tested whether the MPO-inhibitor, 4-Methoxy-TEMPO (MetT), ameliorates experimental IBD. Colitis was induced in C57BL/6 mice by 3% w/v dextran-sodium-sulfate (DSS) in drinking water ad libitum over 9-days with MetT (15 mg/kg; via i. p. injection) or vehicle control (10% v/v DMSO+90% v/v phosphate buffered saline) administered twice daily during DSS challenge. MetT attenuated body-weight loss (50%, p < 0.05, n = 6), improved clinical score (53%, p < 0.05, n = 6) and inhibited serum lipid peroxidation. Histopathological damage decreased markedly in MetT-treated mice, as judged by maintenance of crypt integrity, goblet cell density and decreased cellular infiltrate. Colonic Ly6C⁺, MPO-labelled cells and 3-chlorotyrosine (3-Cl-Tyr) decreased in MetT-treated mice, although biomarkers for nitrosative stress (3-nitro-tyrosine-tyrosine; 3-NO₂-Tyr) and low-molecular weight thiol damage (assessed as glutathione sulfonamide; GSA) were unchanged. Interestingly, MetT did not significantly impact colonic IL-10 and IL-6 levels, suggesting a non-immunomodulatory pathway. Overall, MetT ameliorated the severity of experimental IBD, likely via a mechanism involving the modulation of MPO-mediated damage.

Biomarkers in Inflammatory Bowel Disease-Associated Spondyloarthritis: State of the Art and Unmet Needs

Inflammatory bowel disease-associated spondyloarthritis is a systemic disease characterized by the chronic inflammation of both the gastrointestinal tract and the musculoskeletal system. Since inflammatory bowel disease-associated spondyloarthritis has been associated with a significant diagnostic delay, which may lead to poor quality of life and progression of joint damage, efforts to discover new reliable and noninvasive diagnostic biomarkers have been made. We reviewed the state of the art of biomarker research in inflammatory bowel disease-associated spondyloarthritis, showing that to date it has been largely unsatisfactory. Only a few of the biomarkers that have been investigated are likely to enter the clinical practice upon further validation in independent cohorts. The research of new and innovative biomarkers for inflammatory bowel disease-associated spondyloarthritis is warranted.

Preclinical evaluation of EPHX2 inhibition as a novel treatment for inflammatory bowel disease

Epoxyeicosatrienoic acids (EETs) are signaling lipids produced by cytochrome P450 epoxygenation of arachidonic acid, which are metabolized by EPHX2 (epoxide hydrolase 2, alias soluble epoxide hydrolase or sEH). EETs have pleiotropic effects, including anti-inflammatory activity. Using a Connectivity Map (CMAP) approach, we identified an inverse-correlation between an exemplar EPHX2 inhibitor (EPHX2i) compound response and an inflammatory bowel disease patient-derived signature. To validate the gene-disease link, we tested a pre-clinical tool EPHX2i (GSK1910364) in a mouse disease model, where it showed improved outcomes comparable to or better than the positive control Cyclosporin A. Up-regulation of cytoprotective genes and down-regulation of proinflammatory cytokine production were observed in colon samples obtained from EPHX2i-treated mice. Follow-up immunohistochemistry analysis verified the presence of EPHX2 protein in infiltrated immune cells from Crohn's patient tissue biopsies. We further demonstrated that GSK2256294, a clinical EPHX2i, reduced the production of IL2, IL12p70, IL10 and TNFα in both ulcerative colitis and Crohn's disease patient-derived explant cultures. Interestingly, GSK2256294 reduced IL4 and IFNγ in ulcerative colitis, and IL1β in Crohn's disease specifically, suggesting potential differential effects of GSK2256294 in these two diseases. Taken together, these findings suggest a novel therapeutic use of EPHX2 inhibition for IBD.

Corticotropin-releasing factor induces inflammatory cytokines via the NLRP6-inflammatory cytokine axis in a murine model of irritable bowel syndrome

OBJECTIVE

This study aimed to determine the effect of corticotropin-releasing factor (CRF) on regulating the NOD-like receptor pyrin domain-containing protein 6 (NLRP6)-inflammatory cytokine axis in a murine model of irritable bowel syndrome (IBS).

METHODS

C57BL/6 mice were subjected to water avoidance stress (WAS) for 1 h per day for 10 days, and the abdominal withdrawal reflex (AWR) and colonic inflammation were assessed. We also measured the levels of CRF, NLRP6 inflammasome components, myeloperoxidase, D-lactate, interleukin (IL)-1β, and IL-18. In vitro experiments with Caco-2 cell line were also performed. In addition, we assessed the effect of Clostridium butyricum (C. butyricum) on IBS mice.

RESULTS

IBS mice exhibited visceral hypersensitivity and inflammation, accompanied by increases in CRF, myeloperoxidase, D-lactate, IL-1β, and IL-18 levels, but a decrease in NLRP6 expression. In vitro data showed that CRF suppressed NLRP6, but induced IL-1β and IL-18 levels, in Caco-2 cells. C. butyricum restored CRF levels and maintained the NLRP6-inflammatory cytokine axis in IBS mice.

CONCLUSIONS

CRF induces the NLRP6-inflammatory cytokine axis in IBS mice. C. butyricum could be beneficial in controlling IBS.

Association of Fecal Markers of Environmental Enteric Dysfunction with Zinc and Iron Status among Children at First Two Years of Life in Bangladesh

Environmental enteric dysfunction (EED) causes gut inflammation and increased intestinal permeability leading to deficiencies in micronutrients such as zinc and iron. Fecal markers such as myeloperoxidase (MPO), neopterin (NEO), and alpha-1-anti-trypsin (AAT) can predict EED. The aim of this study was to examine the association between fecal markers of EED with zinc and iron status among children at first 2 years of life. Malnutrition and Enteric Disease Study Bangladeshi birth cohort data were used to conduct this analysis. Multivariable analyses using generalized estimating equations were performed to test the association between individual fecal markers with zinc or iron status of the children. A total of 265 children were enrolled in the study (male:female = 1:1). Of the 627 stool samples collected (N = 222 children), 535, 511, and 577 were accompanied by zinc, ferritin, and soluble transferrin receptor values, respectively. Median (interquartile range [IQR]) values of AAT, MPO, and NEO were 0.33 (0.18-0.62) mg/g, 3,895.42 (1,563.76-8,432.82) ng/mL, and 890.81 (331.57-2,089.04) nmol/L, respectively. Overall, 60%, 71%, and 97% of samples were above the values considered normal in nontropical settings for AAT, MPO, and NEO, respectively. High AAT levels were significantly associated with low ferritin values after adjusting for age and gender (coefficient = -5.85; 95% confidence interval = -11.23 to -0.47; P value = 0.03). No such association was found between AAT and plasma zinc status. Myeloperoxidase and NEO were not associated with plasma zinc or iron status. The study results imply the importance of enteric protein loss in contributing to reduced ferritin levels at first 2 years of life.

Metaproteomics reveals associations between microbiome and intestinal extracellular vesicle proteins in pediatric inflammatory bowel disease

Alterations in gut microbiota have been implicated in the pathogenesis of inflammatory bowel disease (IBD), however factors that mediate the host–microbiota interactions remain largely unknown. Here we collected mucosal-luminal interface samples from a pediatric IBD inception cohort and characterized both the human and microbiota proteins using metaproteomics. We show that microbial proteins related to oxidative stress responses are upregulated in IBD cases compared to controls. In particular, we demonstrate that the expression of human proteins related to oxidative antimicrobial activities is increased in IBD cases and correlates with the alteration of microbial functions. Additionally, we reveal that many of these human proteins are present and show altered abundance in isolated free extracellular vesicles (EVs). Therefore, our study suggests that the alteration of intestinal EV proteomes is associated with the aberrant host–microbiota interactions in IBD.

Gut microbial dysbiosis has been implicated in the pathogenesis of inflammatory bowel disease. Here, the authors examine host-microbiota protein interactions that occur in inflammatory bowel disease; they show an upregulation in proteins related to antimicrobial activities, and alterations in intestinal extracellular vesicles that are associated with aberrant microbiota-interactions.

Associations Among Mucosal and Transmural Healing and Fecal Level of Calprotectin in Children With Crohn's Disease

BACKGROUND & AIMS

Bowel healing is an important goal of therapy for patients with Crohn's disease (CD). Although there have been many studies of mucosal healing, transmural healing (ie, in the bowel wall) has not been investigated in children. We analyzed data from the ImageKids study to determine associations among mucosal, transmural healing and levels of calprotectin and C-reactive protein in children with CD.

METHODS

We collected data from a multi-center study designed to develop 2 magnetic resonance enterography (MRE)-based measures for children with CD (6-18 years old). In our analysis of 151 children (mean age, 14.2 ± 2.4 years), all patients underwent MRE and a complete ileocolonoscopic evaluation; fecal levels of calprotectin and blood levels of C-reactive protein were measured. Mucosal healing was defined as simple endoscopic severity index in CD score below 3, transmural healing as an MRE visual analogue score below 20 mm, and deep healing as a combination of transmural and mucosal healing.

RESULTS

We identified mucosal healing with transmural inflammation in 9 children (6%), transmural healing with mucosal inflammation in 38 children (25%), deep healing in 21 children (14%), and mucosal and transmural inflammation in 83 children (55%). The median level of calprotectin was lowest in children with deep healing (mean level, 10 μg/g; interquartile range, 10-190 μg/g), followed by children with either transmural or mucosal inflammation, and highest in children with mucosal and transmural inflammation (810 μg/g; interquartile range, 539-1737 μg/g) (P < .001). Fecal level of calprotectin identified children with deep healing with an area under the receiver operating characteristic curve value of 0.93 (95% CI, 0.89-0.98); level of C-reactive protein identified children with deep healing with an area under the receiver operating characteristic curve value of 0.81 (95% CI, 0.71-0.9). A calprotectin cutoff value of 100 μg/g identified children with deep healing with 71% sensitivity and 92% specificity; a cutoff value of 300 μg/g identified children with mucosal healing with 80% sensitivity and 81% specificity.

CONCLUSIONS

In a prospective study of children with CD, we found that one-third have healing in only the mucosa or the bowel wall (not both). Levels of fecal calprotectin below 300 μg/identify children with mucosal healing, but a lower cutoff value (below 100 μg/g) is needed to identify children with deep healing. Clinicaltrials.gov no: NCT01881490.

Calprotectin in Daily Practice: Where Do We Stand in 2017?

BACKGROUND

To make a distinction between organic and functional disease is essential for gastroenterologists in their daily practice, but it may be challenging, given the variety and aspecificity of gastrointestinal symptoms among the general population. The clinician aim is to avoid diagnostic delay and to restrict unnecessary invasive and expensive exams.

SUMMARY

Faecal markers, in particular faecal calprotectin (FC), have given proof of being reliable markers of intestinal inflammation with good clinical sensitivity. Calprotectin is useful in the differential diagnosis between inflammatory bowel disease and irritable bowel syndrome, as well as in the follow-up of inflammatory bowel disease patients and in predicting treatment response, with an excellent correlation with endoscopic activity. Its role in collagenous colitis and infectious colitis is less clear and still under investigation. Key Message: Despite the growing evidence supporting its use, many clinicians are uncomfortable in dosing FC, due to its low specificity and the variability of cut-off values. Indeed there are no clear guidelines about how to manage patients with intermediate levels of FC. The aim of this article is to review recent literature on calprotectin and its use. The strong points and the limits of FC measurement will be analysed, and a practical approach in the daily clinical routine will be proposed.

Fecal Galectin-3: A New Promising Biomarker for Severity and Progression of Colorectal Carcinoma

Background and Objectives

The aim of the study was to determine systemic and fecal values of galectin-3 and pro- and anti-inflammatory cytokines in patients with CRC and the relationship with clinicopathological aspects.

Methods

Concentrations of galectin-3, TNF-α, TGF-β, IL-10, and IL-1β were analyzed in samples of blood and stool of 60 patients with CRC.

Results

Systemic concentration of TNF-α was significantly lower in patients with severe diseases (advanced TNM stage, nuclear grade, and poor histological differentiation) as in patients with more progressive CRC (lymph and blood vessel invasion, presence of metastasis). Fecal values of anti-inflammatory cytokines TGF-β and IL-10 were increased in patients with severe stadium of CRC. Fecal concentration of Gal-3 was enhanced in CRC patients with higher nuclear grade, poor tumor tissue differentiation, advanced TNM stage, and metastatic disease. Gal-3/TNF-α ratio in sera and feces had a higher trend in patients with severe and advanced diseases. Positive correlation between fecal Gal-3 and disease severity, tumor progression, and biomarkers AFP and CEA, respectively, was also observed.

Conclusions

Predomination of Gal-3 in patients with advanced diseases may implicate on its role in limiting ongoing proinflammatory processes. The fecal values of Gal-3 can be used as a valuable marker for CRC severity and progression.

Surrogate Fecal Biomarkers in Inflammatory Bowel Disease: Rivals or Complementary Tools of Fecal Calprotectin?

BACKGROUND

Current noninvasive methods for assessing intestinal inflammation in inflammatory bowel disease (IBD) remain unsatisfactory. Along with C-reactive protein and erythrocyte sedimentation rate, fecal calprotectin (FC) is the standard test for assessing IBD activity, even though its specificity and accuracy are not optimal and it lacks a validated cutoff. Over the past few decades, several fecal markers released from intestinal inflammatory cells have been investigated in IBD; they are the subject of this systematic review.

METHODS

A systematic electronic search of the English literature up to April 2017 was performed using Medline and the Cochrane Library. Only papers written in English that analyzed fecal biomarkers in IBD were included. In vitro studies, animal studies, studies on blood/serum samples, and studies analyzing FC or fecal lactoferrin alone were excluded.

RESULTS

Out of 1023 citations, 125 eligible studies were identified. Data were grouped according to each fecal marker including S100A12, high-mobility group box 1, neopterin, polymorphonuclear neutrophil elastase, fecal hemoglobin, alpha1-antitrypsin, human neutrophil peptides, neutrophil gelatinase-associated lipocalin, chitinase 3-like-1, matrix metalloproteinase 9, lysozyme, M2-pyruvate kinase, myeloperoxidase, fecal eosinophil proteins, human beta-defensin-2, and beta-glucuronidase. Some of these markers showed a high sensitivity and specificity and correlated with disease activity, response to therapy, and mucosal healing. Furthermore, they showed a potential utility in the prediction of clinical relapse.

CONCLUSIONS

Several fecal biomarkers have the potential to become useful tools complementing FC in IBD diagnosis and monitoring. However, wide variability in their accuracy in assessment of intestinal inflammation suggests the need for further studies.

Validation of a care pathway for the use of faecal calprotectin in monitoring patients with Crohn's disease

INTRODUCTION

We have previously published an evidence-based care pathway for the use of faecal calprotectin (FC) to monitor patients with Crohn's disease established on therapy. Patients are treated as low, intermediate or high risk of continuing Crohn's disease activity based on their FC, whatever their phenotype and surgical status are. Low-risk patients (FC <100 µg/g) are offered 12 monthly follow-ups or step down of therapy if asymptomatic or initial expectant symptomatic treatment. Intermediate-risk patients (FC 100-250 µg/g) are reviewed at 6 months with a repeat FC. High-risk patients (two consecutive FCs >250 µg/g) are flagged up to the responsible clinician as likely having an active Crohn's disease.

METHODS

To validate this care pathway over a 2-year period, by determining its negative predictive value (NPV) and positive predictive value (PPV).

RESULTS

123 patients were managed by means of the care pathway for a mean of 24.4 months. The NPV and PPV were 0.97 (CI 0.93 to 0.98) and 0.85 (CI 0.80 to 0.94), respectively (sensitivity: 0.92 (0.83 to 0.96) and specificity: 0.95 (0.92 to 0.98)). Importantly 69% of patients with FC >250 µg/g were in clinical remission, the care pathway identifying patients who would benefit from presymptomatic disease modification.

CONCLUSIONS

This validation of a pragmatic clinical care pathway demonstrates a safe and effective mechanism by which to use FC to monitor risk of disease activity in patients with Crohn's disease established on therapy. It provides a framework for prioritising follow-up and for identifying patients at risk of continuing disease activity or those in whom therapy could be stepped down.

Fecal biomarkers in inflammatory bowel disease: how, when and why?

Over the last thirty years knowledge on fecal biomarkers (FM) has substantially increased. Nowadays these non-invasive inflammation markers are used in the daily management of inflammatory bowel disease (IBD). The interest in investigating FM was motivated by the need of a simple, quick, disposable and less invasive marker of disease activity, which might remove the need for endoscopy when following up with patients. Areas covered: Current literature was reviewed for articles regarding the role of FM in IBD diagnosis, activity, flare prediction, medication and surgical treatment response as well as how FM may differ in adult and paediatric IBD patient populations. Expert commentary: Although FM is relevant in IBD patient follow-up, there isn't enough data regarding FM reference values for different ages, different disease subtypes, disease localization/extension or response to therapy. Serial measurements of FM for each patient may be useful in accessing relapse in most patients. FM presented more consistent results when used as a predictive tool of relapse after ileocecal surgery in Crohn's disease. Ongoing research will clarify FM role in decision-making IBD daily practice.

Fecal calprotectin as a non-invasive biomarker for intestinal involvement of Behçet's disease

BACKGROUND AND AIM

The diagnostic and prognostic values of fecal calprotectin (FC) levels in patients with inflammatory bowel diseases have been proven. However, little is known about the usefulness of FC measurement in predicting intestinal involvement of Behçet's disease (BD).

METHODS

Forty-four consecutive patients with systemic BD who underwent colonoscopy for the evaluation of gastrointestinal symptoms were prospectively enrolled between November 2012 and March 2014 in a single tertiary medical center. Fecal specimens from the patients were obtained the day before bowel cleansing and 3 months after colonoscopy.

RESULTS

Twenty-five patients showed intestinal ulcerations on colonoscopy (12 [48.0%] typical and 13 [52.0%] atypical ulcerations). The median FC level in the intestinal BD group was significantly higher than that in the non-diagnostic group (112.53 [6.86-1604.39] vs 31.64 [5.46-347.60] µg/g, respectively, P = 0.003). Moreover, the typical ulceration group showed a significantly higher median FC level than the atypical ulceration group in patients with intestinal BD (435.995 [75.65-1604.39] vs 71.42 [6.86-476.94] µg/g, respectively, P = 0.033). Multivariate analysis revealed higher FC as an independent predictor of intestinal BD (OR = 38.776; 95% CI = 2.306-652.021; P = 0.011). The cut-off level of FC for predicting intestinal BD was 68.89 µg/g (76% sensitivity and 79% specificity). The absolute changes between fecal calprotectin levels and the disease activity index of intestinal BD from initial diagnosis of intestinal BD to 3 months after diagnosis were significantly correlated (Pearson's correlation coefficient = 0.470, P = 0.027).

CONCLUSION

The FC level might serve as a non-invasive surrogate marker of intestinal involvement of BD.

Patient-performed extraction of faecal calprotectin

BACKGROUND

Faecal (f-) calprotectin is a widely used marker for intestinal inflammation. However, extraction procedure is time consuming and cumbersome. The main aim of this study was to evaluate patient-performed extraction of f-calprotectin compared to extraction performed in the laboratory.

METHODS

A total of 81 adult patients with an established diagnosis of inflammatory bowel disease provided two samples from the same bowel movement, one conventional faeces sample and one sample with a patient administered extraction device. A laboratory technician extracted the conventional faeces sample with the same extraction device.

RESULTS

F-calprotectin results from the laboratory-performed extraction and the patient-performed extraction correlated significantly, with a Spearman rank correlation coefficient of 0.92. Method comparison showed a slope of 1.20 (95% confidence interval 1.08-1.36) with intercept of -0.30 (95% confidence interval -9.00 to 4.62). This demonstrates a small proportional difference between the results from the home extracted samples and the results from the laboratory extracted samples, where the home extracted samples are slightly higher. However, six of the 81 patients had made obvious mistakes in the extraction process and their samples were excluded from the study.

CONCLUSIONS

Patient administered extraction of f-calprotectin can be a realistic alternative for selected patients. However, instructions must be very precise to avoid mistakes.

Fecal Myeloperoxidase as a Biomarker for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic condition involving the inflammation of the colon and small intestine. IBD affects as many as 1.4 million people in the U.S. alone and costs the health care industry over $1.7 billion annually. Managing IBD normally requires invasive and often discomforting diagnostic tests. In an effort to alleviate the painful and costly nature of traditional diagnosis, there has been increasing research initiative focused on noninvasive biomarkers. PubMed, provided by the United States National Library of Medicine (NLM) at the National Institutes of Health, was utilized with the following search terms: 1) myeloperoxidase (MPO) 2), inflammatory bowel disease (IBD), and 3) neutrophils. The following terms were used interchangeably with search terms 1-3: 4) costs, 5) biomarkers, 6) review, and 7) etiology. In the context of IBD, myeloperoxidase (MPO), a lysosomal protein found in neutrophils, may serve as a viable biomarker for assessing disease status. Several studies demonstrated increased levels of neutrophils in patients with active IBD. Furthermore, studies have found significantly higher levels of MPO in patients with active IBD compared to patients without IBD as well as patients with inactive IBD. MPO is also expressed in higher concentrations in patients with more severe forms of IBD. When measuring treatment efficacy, MPO levels are indicative of the quality of response. MPO may serve as an important diagnostic and prognostic tool in assessing IBD status. 

Accuracies of fecal calprotectin, lactoferrin, M2-pyruvate kinase, neopterin and zonulin to predict the response to infliximab in ulcerative colitis

BACKGROUND

Fecal markers might predict the response to anti-TNFα in ulcerative colitis (UC).

AIMS

To compare the performance of fecal calprotectin (fCal), lactoferrin (fLact), M2-PK (fM2-PK), neopterin (fNeo), and zonulin (fZon) to predict the response to therapy in active UC patients.

METHODS

Disease activity from 31 consecutive patients with an active UC, treated with infliximab (IFX) was assessed by the Mayo score at baseline and at week 14 and by the partial Mayo score at W52 and stool samples collected for fecal marker measurements at W0, W2, and W14.

RESULTS

At W14, 19 patients (61%) were responders to IFX induction. The median levels of fCal, fLact and fM2-PK drop dramatically from baseline to W14 in clinical responders. At W2, fM2-PK, fLact and fCal levels predicted accurately the response to IFX induction. At W14, fLact, fCal, and fM2-PK were individually reliable markers to predict sustained response at W52. The performances of fNeo and fZon were weaker in this setting.

CONCLUSIONS

The performance of fM2-PK at W2 to predict response to induction therapy with IFX was superior to that of fLact and fCal, whereas monitoring fLact was the best tool to predict adequately the course of the disease at one year under maintenance IFX in UC.