The role and utility of faecal markers in inflammatory bowel disease

Role of faecal calprotectin as a predictor of endoscopic activity in paediatric patients with ulcerative colitis

INTRODUCTION

Colonoscopy is currently considered to be the gold standard for evaluation of colonic mucosa inflammation in patients with ulcerative colitis (UC), but the procedure is invasive and cannot be repeated frequently, especially in the paediatric population. The aim of this study was to assess the role of faecal calprotectin (FC) as a predictor of endoscopic disease activity in paediatric patients with UC in clinical remission.

MATERIAL AND METHODS

Single-centre prospective study. Clinical remission was defined as Paediatric Ulcerative Colitis Activity Index <10. Endoscopic findings were assessed according to the Mayo Endoscopic Subscore (MES). MES≤1 was defined as endoscopic remission. All participants provided fresh faecal samples for measurement of FC.

RESULTS

A total of 34 visits of 24 children with UC were included in the study. There was a strong positive correlation between FC levels and endoscopic disease activity (n=34, r=0.83, p<0.001). The median FC levels in the subgroup with endoscopic activity (MES 2-3) were significantly higher than the median FC levels in the subgroup without endoscopic activity (MES≤1) (1000μg/g, IQR 575-1800μg/g vs. 100μg/g, IQR 80-223μg/g, p<0.001). At a cut-off of 298.5μg/g, FC had 92.3% sensitivity, 95.2% specificity and an AUROC 0.974 (SE 0.023, 95% CI 0.93-1, p<0.001) to predict endoscopic activity.

DISCUSSION

FC is an accurate surrogate marker of endoscopic activity in children with clinically quiescent UC.

Molecular characterization of Blastocystis subtypes in HIV-positive patients and evaluation of risk factors for colonization

Background

Blastocystis is one of the most common intestinal protozoa in human faecal samples with uncertain impact on public health. Studies on the prevalence of Blastocystis in HIV-positive patients are limited and dated.

Methods

A cross-sectional study was carried out involving 156 HIV-positive patients to evaluate the prevalence of Blastocystis-subtypes by molecular amplification and sequencing the small subunit rRNA gene (SSU rDNA), to identify the risk factors for its transmission, to examine the relationship between the presence of the protist and gastrointestinal disorders. Furthermore, the evaluation of the faecal calprotectin by immunoassay from a sample of subjects was performed to evaluate the gut inflammation in Blastocystis-carriers.

Results

Blastocystis-subtypes ST1, ST2, ST3, ST4 were identified in 39 HIV-positive patients (25%). No correlation was found between the presence of the protist and virological or epidemiological risk factors. Blastocystis was more frequently detected in homosexual subjects (p = 0.037) infected by other enteric protozoa (p = 0.0001) and with flatulence (p = 0.024). No significant differences in calprotectin level was found between Blastocystis-carriers and free ones.

Conclusions

Blastocystis is quite common in HIV-positive patients on ART showing in examined patients 25% prevalence. Homosexual behaviour may represent a risk factor for its transmission, while CD4 count and viremia didn’t correlate with the presence of the protist. The pathogenetic role of Blastocystis remains unclear and no gut inflammation status was detected in Blastocystis-carriers. The only symptom associated with Blastocystis was the flatulence, evidencing a link between the presence of the protist and the composition and stability of gut microbiota.

Enriched Environmental Conditions Modify the Gut Microbiome Composition and Fecal Markers of Inflammation in Parkinson's Disease

Recent findings suggest an implication of the gut microbiome in Parkinson's disease (PD) patients. PD onset and progression has also been linked with various environmental factors such as physical activity, exposure to pesticides, head injury, nicotine, and dietary factors. In this study, we used a mouse model, overexpressing the complete human SNCA gene (SNCA-TG mice) modeling familial and sporadic forms of PD to study whether environmental conditions such as standard vs. enriched environment changes the gut microbiome and influences disease progression. We performed 16S rRNA DNA sequencing on fecal samples for microbiome analysis and studied fecal inflammatory calprotectin from the colon of control and SNCA-TG mice kept under standard environment (SE) and enriched environment (EE) conditions. The overall composition of the gut microbiota was not changed in SNCA-TG mice compared with WT in EE with respect to SE. However, individual gut bacteria at genus level such as Lactobacillus sp. was a significant changed in the SNCA-TG mice. EE significantly reduced colon fecal inflammatory calprotectin protein in WT and SNCA-TG EE compared to SE. Moreover, EE reduces the pro-inflammatory cytokines in the feces and inflammation inducing genes in the colon. Our data suggest that an enriched social environment has a positive effect on the induction of SNCA mediated inflammation in the intestine and by modulating anti-inflammatory gut bacteria.

The combination of wheat peptides and fucoidan protects against chronic superficial gastritis and alters gut microbiota: a double-blinded, placebo-controlled study

PURPOSE

Chronic gastritis is observed in almost half world population. Traditional medications against chronic gastritis might produce adverse effects, so alternative nutritional strategies are needed to prevent the aggravation of gastric mucosal damage. The aim of this study is to evaluate the protective effect of the combination of wheat peptides and fucoidan (WPF) on adults diagnosed with chronic superficial gastritis in a randomized, double-blind, placebo-controlled clinical trial.

METHODS

Participants were randomized to receive WPF (N = 53) or placebo (N = 53) once daily for 45 days. Pathological grading of gastric mucosal damage was scored using gastroscopy. Fecal samples were collected for the determination of calprotectin, short chain fatty acids (SCFA) levels and metagenomics analysis. Questionnaires for self-reported gastrointestinal discomforts, life quality and food frequency were collected throughout the study.

RESULTS

WPF intervention reduced gastric mucosal damage in 70% subjects (P < 0.001). Significantly less stomach pain (P < 0.001), belching (P = 0.028), bloating (P < 0.001), acid reflux (P < 0.001), loss of appetite (P = 0.021), increased food intake (P = 0.020), and promoted life quality (P = 0.014) were reported in the WPF group. WPF intervention significantly decreased fecal calprotectin level (P = 0.003) while slightly increased fecal SCFAs level (P = 0.092). In addition, we found altered microbiota composition post-intervention with increased Bifidobacterium pseudocatenulatum (P = 0.032), Eubacterium siraeum (P = 0.036), Bacteroides intestinalis (P = 0.024) and decreased Prevotella copri (P = 0.055).

CONCLUSIONS

WPF intervention could be utilized as a nutritional alternative to mitigate the progression of chronic gastritis. Furthermore, WPF played an important role in altering gut microbial profile and SCFA production, which might benefit the lower gastrointestinal tract.

Withdrawal of Azathioprine in Inflammatory Bowel Disease Patients Who Sustain Remission: New Risk Factors for Relapse

BACKGROUND

The benefits of immunosuppressants for sustaining remission and preventing flares of IBD are well known. However, optimal timing for withdrawal has not been determined.

AIMS

The objective of this study was to calculate the risk of relapse and predictors after withdrawal of azathioprine (AZA) monotherapy in patients who sustain deep remission.

METHODS

This was a multicenter observational study of patients with IBD in remission whose immunosuppressant had been withdrawn. We recorded demographic variables, disease data, laboratory values, and the results of imaging tests performed at withdrawal and, in patients who relapsed, time to relapse and the efficacy of reintroducing the drug.

RESULTS

Ninety-five patients were included (35 UC and 60 CD). The mean duration of AZA treatment was 87 and 77 months for UC and CD, respectively. Endoscopic remission was evaluated in 23 patients with UC and 35 with CD. After AZA withdrawal, 91% patients with UC and 67% with CD received high doses of salicylates. A total of 26 patients relapsed. The cumulative relapse rate at 5 years was 46% for CD and UC. AZA was reintroduced in 19 patients, of whom 14 responded. Predictors of relapse were corticosteroid dependence, early introduction of AZA (CD), and late introduction of AZA (UC).

CONCLUSIONS

Almost half of the patients in whom AZA was withdrawn were in remission at 5 years. The candidates for withdrawal could be better identified based on corticosteroid dependence, previous surgery, timing of initiation, and indication for AZA.

Systematic Review with Meta-Analysis: Fecal Calprotectin as a Surrogate Marker for Predicting Relapse in Adults with Ulcerative Colitis

The clinical course of ulcerative colitis (UC) is featured by remission and relapse, which remains unpredictable. Recent studies revealed that fecal calprotectin (FC) could predict clinical relapse for UC patients in remission, which has not yet been well accepted. To detect the predictive value of FC for clinical relapse in adult UC patients based on updated literature, we carried out a comprehensive electronic search of PubMed, Web of Science, Embase, and the Cochrane Library to identify all eligible studies. Diagnostic accuracy including pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and pooled area under the receiver operating characteristic (AUROC) was calculated using a random effects model. Heterogeneity across studies was assessed by the I 2 metric. Sources of heterogeneity were detected using subgroup analysis. Metaregression was used to test potential factors correlated to DOR. Publication bias was assessed using Deek's funnel plots. In our study, 14 articles enrolling a total of 1110 participants were finally included, and all articles underwent a quality assessment. Pooled sensitivity, specificity, PLR, and NLR with 95% confidence intervals (CIs) were 0.75 (95% CI: 0.70-0.79), 0.77 (95% CI: 0.74-0.80), 3.45 (95% CI: 2.31-5.14), and 0.37 (95% CI: 0.28-0.49) respectively. The area under the summary receiver operating characteristic (sROC) curve was 0.82, and the diagnostic odds ratio was 10.54 (95% CI: 6.16-18.02). Our study suggested that FC is useful in predicting clinical relapse for adult UC patients in remission as a simple and noninvasive marker.

Does fecal calprotectin equally and accurately measure disease activity in small bowel and large bowel Crohn's disease?: a systematic review

Fecal calprotectin (FC) is a highly sensitive disease activity biomarker in inflammatory bowel disease. However, there are conflicting reports on whether the diagnostic accuracy in Crohn's disease is influenced by disease location. The aim of this study was to undertake a systematic review of the published literature. Relevant databases were searched from inception to November 8, 2016 for cohort and case control studies which had data on FC in patients with isolated small bowel (SB) and large bowel (LB) Crohn's disease. Reference standards for disease activity were endoscopy, magnetic resonance imaging, computed tomography or a combination of these. The QUADAS-2 research tool was used to assess the risk of bias. There were 5,619 records identified at initial search. The 2,098 duplicates were removed and 3,521 records screened. Sixty-one full text articles were assessed for eligibility and 16 studies were included in the final review with sensitivities and specificities per disease location available from 8 studies. Sensitivities of FC at SB and LB locations ranged from 42.9% to 100% and 66.7% to 100% respectively while corresponding specificities were 50% to 100% and 28.6% to 100% respectively. The sensitivities and specificities of FC to accurately measure disease activity in Crohn's disease at different disease locations are diverse and no firm conclusion can be made. Better studies need to be undertaken to categorically answer the effect of disease location on the diagnostic accuracy of FC.

ACG Clinical Guideline: Ulcerative Colitis in Adults

Ulcerative colitis (UC) is an idiopathic inflammatory disorder. These guidelines indicate the preferred approach to the management of adults with UC and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process. In instances where the evidence was not appropriate for GRADE, but there was consensus of significant clinical merit, "key concept" statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not only, approach to clinical scenarios.

Assessing intestinal permeability in Crohn's disease patients using orally administered 52Cr-EDTA

Background

Intestinal permeability can be assessed by monitoring renal excretion of orally administered radioactively ⁵¹Cr-labeled ethylenediaminetetraacetic acid (⁵¹Cr-EDTA). Although considered safe, patient participation in using radio-labeled tracers is low. Here, we used orally administered ⁵²Cr-EDTA as non-radioactive alternative to assess intestinal permeability in CD and analyzed the association with disease activity, disease location and gut microbial dysbiosis.

Materials and methods

60 CD patients with low (n = 25) and increased (n = 35) fecal calprotectin levels (cut-off: 100 μg/g feces) ingested 20 mL ⁵²Cr-EDTA (20 mmol/L) solution whereafter 24-h urine was collected. Urinary ⁵²Cr-EDTA concentrations were quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Fecal Enterobacteriaceae and Faecalibacterium prausnitzii were quantified using FISH. Correlations between urinary ⁵²Cr-EDTA excretion and other parameters were established using nonparametric Spearman’s correlation coefficients (ρ).

Results

CD patients with increased fecal calprotectin levels (> 100 μg/g) demonstrated an elevated urinary ⁵²Cr-EDTA/creatinine ratio (772 vs. 636 μmol/mol, P = 0.132). Patients with primarily colonic disease showed the highest ⁵²Cr-EDTA excretion. Importantly, a positive correlation was observed for the urinary ⁵²Cr-EDTA/creatinine ratio and fecal calprotectin levels (ρ = 0.325, P < 0.05). Finally, urinary ⁵²Cr-EDTA/creatinine ratio negatively correlated with the relative abundance of Faecalibacterium prausnitzii (ρ = -0.221, P = 0.092), while positively correlating with Enterobacteriaceae (ρ = 0.202, P = 0.126).

Conclusions

Orally administered and renal excreted ⁵²Cr-EDTA may be used to assess intestinal permeability in CD and correlates with fecal calprotectin levels and bacterial species relevant to CD. This test may improve non-invasive detection of disease exacerbations and help monitor disease activity.

Biomarkers of inflammatory bowel disease activity

The review presents data on calprotectin, lactoferrin, leukocytes labeled with isotope indium 111In, calgranulin C and pyruvate kinase type M2 - highly sensitive biomarkers to assess the severity of intestinal inflammation. Their importance in diagnostics, determination of treatment efficiency, including as predictors of recurrence of ulcerative colitis and Crohn's disease is shown.

Damage-associated molecular patterns in inflammatory bowel disease: From biomarkers to therapeutic targets

The chronic inflammatory process underlying inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, derives from the interplay of several components in a genetically susceptible host. These components include environmental elements and gut microbiota a dysbiosis. For decades, immune abnormalities have been investigated as critically important in IBD pathogenesis, and attempts to develop effective therapies have predominantly targeted the immune system. Nevertheless, immune events represent only one of the constituents contributing to IBD pathogenesis within the context of the complex cellular and molecular network underlying chronic intestinal inflammation. These factors need to be appreciated within the milieu of non-immune components. Damage-associated molecular patterns (DAMPs), which are essentially endogenous stress proteins expressed or released as a result of cell or tissue damage, have been shown to act as direct pro-inflammatory mediators. Excessive or persistent signalling mediated by such molecules can underlie several chronic inflammatory disorders, including IBD. The release of endogenous DAMPs amplifies the inflammatory response driven by immune and non-immune cells and promotes epigenetic reprogramming in IBD. The effects determine pathologic changes, which may sustain chronic intestinal inflammation and also underlie specific disease phenotypes. In addition to highlighting the potential use of DAMPs such as calprotectin as biomarkers, research on DAMPs may reveal novel mechanistic associations in IBD pathogenesis and is expected to uncover putative therapeutic targets.

Fecal markers in the management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by periods of symptomatic remission and relapse. Diagnosis and assessment of IBD are based on clinical evaluation, serum parameters, radiology, and endoscopy. Fecal markers have emerged as new diagnostic tools to detect and monitor intestinal inflammation. Fecal calprotectin (FC) and lactoferrin (FL) were identified decades ago as potentially revolutionary markers for IBD. Following these discoveries numerous additional markers, including S100A12, M2-PK, metalloproteinases, hemoglobin, myeloperoxidase, lysozyme, polymorphonuclear elastase, neopterin, and nitric oxide, have also been suggested as novel markers of IBD. But only FC and FL are used for the management of clinical IBD patients. The objective of this review is to introduce the clinical applications of fecal markers in the diagnosis, monitoring and prediction of outcomes of inflammatory bowel disease.

Faecal calprotectin level for assessing endoscopic activity and predicting future clinical course in patients with moderately active ulcerative colitis undergoing granulomonocytapheresis: a prospective cohort study

Background

Calprotectin is a stable neutrophil protein, which can be measured in faecal samples. The faecal level of calprotectin increases during disease activity in ulcerative colitis (UC). Nonetheless, the relevance of faecal calprotectin (FC) measurement during granulomonocytapheresis (GMA) for UC has not yet been fully evaluated. This prospective study was to investigate the value of FC for assessing disease activity and predicting clinical course in UC patients undergoing GMA therapy.

Methods

One hundred and eighty-four patients with moderately active UC with endoscopic activity (Mayo endoscopic subscore [MES] = 2 or 3) received Adacolumn GMA therapy (10 apheresis sessions over consecutive 5 weeks). Patients who achieved clinical remission were subsequently given maintenance medications for 12 months. FC levels were measured at entry and after treatment.

Results

After GMA, 80 of the 184 patients (43%) achieved clinical remission, and 51 (28%) achieved mucosal healing (MH; MES = 0 or 1). The median FC level significantly decreased in patients who achieved MH (P = 0.02), but not in those without MH. Thirty-four patients (43%) relapsed during the 12-month follow-up. The median FC level at the end of GMA therapy was significantly higher in patients who subsequently relapsed than in those who maintained remission (149.5 vs 45.5 μg/g, P < 0.001). A cut off value of 114 μg/g had a sensitivity of 76% and a specificity of 85% to predict future relapse.

Conclusions

Our findings indicate that FC is a relevant biomarker, which is convenient to measure for assessing endoscopic activity and predicting relapse in patients who achieve remission following a course of GMA therapy.

Diagnostic Accuracy of Serum and Urine S100A8/A9 and Serum Amyloid A in Probable Acute Abdominal Pain at Emergency Department

Study Design

This study was performed to investigate the diagnostic values of some inflammatory biomarkers in abdominal pain.

Methods

Patients over 18 years of age with acute recent abdominal pain who presented to the Emergency Department were evaluated. Serum and urinary samples were taken and evaluated for serum and urine S100A8/A9 and serum amyloid A. All patients were referred to a surgeon and were followed up until the final diagnosis. In the end, the final diagnosis was compared with the levels of biomarkers.

Results

Of a total of 181 patients, 71 underwent surgery and 110 patients did not need surgery after they were clinically diagnosed. Mean levels of serum and urine S100A8/A9 had a significant difference between two groups, but serum amyloid A did not show. The diagnostic accuracy of serum S100A8/A9, urine S100A8/A9, and serum amyloid A was 86%, 79%, and 50%, respectively, in anticipation of the need or no need for surgery in acute abdominal pain.

Conclusions

Our study showed that in acute abdominal pain, serum and urine S100A8/A9 can be useful indicators of the need for surgery, but serum amyloid A had a low and nonsignificant diagnostic accuracy.

Diagnostic Potential of Systemic Eosinophil-Associated Cytokines and Growth Factors in IBD

Despite the acknowledged contribution of eosinophils to the disease pathogenesis, available data on cytokines closely related to the peripheral eosinophils in inflammatory bowel disease (IBD) are scattered. We assessed the concentrations of eosinophil-associated cytokines and growth factors in the group of 277 individuals (101 patients with Crohn's disease (CD), 77 with ulcerative colitis (UC), 16 with irritable bowel syndrome (IBS), and 83 healthy controls) and referred to IBD activity and the levels of hsCRP. As compared to IBS patients or healthy controls, patients with CD had significantly higher levels of IL5, IL8, IL12(p70), GM-CSF, and TNFα and patients with UC, the levels of eotaxin, IL4, IL5, IL8, IL12(p70), IL13, GM-CSF, and TNFα were also higher. As compared to CD patients, patients with UC had significantly higher levels of eotaxin, IL4, IL5, IL8, and IL1. In turn, the concentrations of hsCRP were significantly higher in CD than UC. Except for IL13, all cytokines and hsCRP positively correlated with CDAI. In UC, a positive correlation with MDAI was observed for hsCRP, GM-CSF, IL12(p70), and IFNγ and a negative one for IL8. The concentrations of hsCRP, GM-CSF, IFNγ, IL12(p70), and RANTES were higher in UC patients with active than inactive disease whereas those of IL8 and TNFα were significantly lower. Eotaxin, determined individually or in a panel with IFNγ and hsCRP, showed fair accuracy in differentiating CD from UC. If confirmed on a larger representation of IBS patients, IL8 might support differential diagnosis of organic and functional conditions of the bowel. GM-CSF, in turn, demonstrated to be an excellent indicator of bowel inflammation and may be taken into consideration as a noninvasive marker of mucosal healing. In summary, eosinophil-associated cytokines are elevated in IBD, more pronouncedly in UC, and may support the differential diagnosis of IBD and aid in monitoring of mucosal healing.

The Role of Biomarkers in Clinical Trials of Inflammatory Bowel Disease

Clinical trials require valid outcome measures to assess the therapeutic benefit of investigational agents. Recently, regulatory authorities have mandated the use of patient-reported outcomes in combination with an objective measure of disease activity as primary outcome measures in inflammatory bowel disease trials. Endoscopy has commonly fulfilled the latter role; however, due to the costs and complexity of these assessments, interest has emerged in the use of noninvasive biomarkers. The role of C-reactive protein, fecal calprotectin, and fecal lactoferrin in clinical research is discussed.

Gene expression in adverse reaction to metal debris around metal-on-metal arthroplasty: An RNA-Seq-based study

Joint replacement surgery is a standard treatment of advanced osteoarthritis (OA). Since 2000, cobalt-chromium (CoCr) metal-on-metal (MoM) implants were widely used in hip arthroplasties. Some patients developed "adverse reaction to metal debris" (ARMD) around the prosthesis, resulting in a need for revision surgery. In the present study, we addressed the pathogenesis of ARMD by genome-wide expression analysis. Pseudosynovial ARMD tissue was obtained from revision surgery of Articular Surface Replacement (ASR, DePuy, Warsaw, IN, USA) hip arthroplasties. Control tissue was 1) OA synovium from primary hip arthroplasties and 2) inflammatory pseudosynovial tissue from metal-on-plastic (MoP) implant revisions. In ARMD tissue, the expression of 1446 genes was significantly increased and that of 1881 decreased as compared to OA synovium. Genes associated with immune response, tissue development and certain leukocyte signaling pathways were enriched in the differently (FC > 2) expressed genes. The network analysis proposed PRKACB, CD2, CD52 and CD53 as the central regulators of the greatest (FC > 10) differences. When ARMD tissue was compared to MoP tissue, the expression of 16 genes was significantly higher and that of 21 lower. Many of these genes were associated with redox homeostasis, metal ion binding and transport, macrophage activation and apoptosis. Interestingly, genes central to myofibroblast (AEBP1 and DES) and osteoclast (CCL21, TREM2 and CKB) development were upregulated in the MoP tissue. In network analysis, IL8, NQO1, GSTT1 and HMOX1 were identified as potential central regulators of the changes. In conclusion, excessive amounts of CoCr debris produced by MoM hip implants induces in a group of patients a unique adverse reaction characterized with enhanced expression of genes associated with inflammation, redox homeostasis, metal ion binding and transport, macrophage activation and apoptosis.

Fecal Calprotectin Test Performed at Home: A Prospective Study of Pediatric Patients With Inflammatory Bowel Disease

OBJECTIVES

Measuring fecal calprotectin (FC) in a laboratory is time-consuming and that is why home tests have been developed. We studied the use of an FC home test in pediatric patients with inflammatory bowel disease (PIBD) in real-life settings.

METHODS

The patients were asked to perform the IBDoc FC home test monthly for 6 months and to report their clinical disease activity at testing. Clinical decision-making, however, was guided by routine FC enzyme-linked immunosorbent assay (ELISA) for patients with raised IBDoc values. Spare frozen samples were analyzed using ELISA and IBDoc in the laboratory. The participants completed a questionnaire about FC testing at the start and end of the study.

RESULTS

Of the 52 patients, 35 (67%) ages 5 to 18 years completed the study, and 197 home tests were performed. Of these, 15% failed, mainly because of technical reasons. Just under half of the patients (47%) considered home testing comparable or superior to routine testing. In contrast, the parents were unsatisfied (61%), mostly because the IBDoc results were significantly different from ELISA and they found the phone application difficult to handle but whenever the IBDoc was performed by a laboratory professional it was comparable with ELISA, suggesting that practical issues hampered home testing. Despite their reservations, more than 80% of parents felt that home testing would improve disease management.

CONCLUSIONS

PIBD patients and their families were interested in FC home monitoring and willing to adopt testing as a part of their disease management, but this approach requires thorough guidance.

Fecal Calprotectin: A Comparison of Two Commercial Enzymoimmunoassays and Study of Fecal Extract Stability at Room Temperature

Background

The aims of the study were: 1) to compare the fecal calprotectin (fCal) assay results with Calprolab™ ELISA (HRP) (Calpro AS) versus our routine method, Elia™ fluoroenzymoimmunoassay (Thermo Fisher), and 2) to determine whether the fCal assay results do not vary following storage of the extract at room temperature for 4 days with the Calpro AS buffer, this being the estimated shipment time from the home of the patient, and an aspect little studied to date.

Methods

The fCal was determined in 198 patients divided into three groups: inflammatory bowel disease (IBD), organic intestinal disease, and functional intestinal disorders. Fecal extraction was carried out using the Roche Diagnostics kit with the corresponding specific buffers.

Results

The fCal assay with the Thermo Fisher method was found to be more sensitive but less specific than with the Calpro AS technique. The positive predictive value was low (just over 50%), though the negative predictive value was high (over 90%) with both methods. The likelihood ratios revealed small but occasionally important pre- versus post-test differences. When we compared the two methods, the Spearman correlation coefficient (ρ) was 0.819 (95% CI: 0.768 - 0.860) (P < 0.0001), reflecting a positive correlation. Similarly, when stratifying the fCal results into < 50 µg/g, 50 - 100 µg/g and > 100 µg/g, the resulting Cohen’s kappa coefficient was 0.7766 (95% CI: 0.7025 - 0.8507), reflecting a substantial agreement between both methods. The stability of fCal was high in fecal extracts with the Calpro AS extraction buffer at room temperature for 4 days, which yielded a Spearman correlation coefficient of 0.951 (95% CI: 0.933 - 0.965), when the results were compared to those of the recent extracts (P < 0.0001).

Conclusions

A positive correlation was observed between the two methods. In view of the high negative predictive value obtained with fCal, the presence of organic disease is highly unlikely in the presence of a normal concentration of this marker. We also confirmed the excellent stability of fCal in fecal extracts with the Calpro AS extraction buffer stored at room temperature. Thus, and for the sake of convenience and hygiene, it would be ideal for the patient to perform the extraction at home.

MUB40 Binds to Lactoferrin and Stands as a Specific Neutrophil Marker

Neutrophils represent the most abundant immune cells recruited to inflamed tissues. A lack of dedicated tools has hampered their detection and study. We show that a synthesized peptide, MUB₄₀, binds to lactoferrin, the most abundant protein stored in neutrophil-specific and tertiary granules. Lactoferrin is specifically produced by neutrophils among other leukocytes, making MUB₄₀ a specific neutrophil marker. Naive mammalian neutrophils (human, guinea pig, mouse, rabbit) were labeled by fluorescent MUB₄₀ conjugates (-Cy5, Dylight405). A peptidase-resistant retro-inverso MUB₄₀ (RI-MUB₄₀) was synthesized and its lactoferrin-binding property validated. Neutrophil lactoferrin secretion during in vitro Shigella infection was assessed with RI-MUB₄₀-Cy5 using live cell microscopy. Systemically administered RI-MUB₄₀-Cy5 accumulated at sites of inflammation in a mouse arthritis inflammation model in vivo and showed usefulness as a potential tool for inflammation detection using non-invasive imaging. Improving neutrophil detection with the universal and specific MUB₄₀ marker will aid the study of broad ranges of inflammatory diseases.

Increased fecal calprotectin levels in Crohn's disease correlate with elevated serum Th1- and Th17-associated cytokines

Background

Patient-reported symptoms and endoscopic disease activity do not correlate well in Crohn’s disease (CD). This warrants the need for reliable biomarkers to early detect active intestinal inflammation. Currently, the fecal calprotectin level is the most commonly used biomarker for inflammatory activity in CD. However, the diagnostic accuracy of the fecal calprotectin level is not fully efficacious and diagnosis may be further improved by the identification of other biomarkers for active CD. Here, we studied the association of a variety of serum disease markers with fecal calprotectin levels in CD patients.

Methods

39 CD patients were included and subdivided into ‘normal’ (defined as < 200 mg/kg feces) and ‘increased’ (defined as > 200 mg/kg feces) fecal calprotectin level groups. Serum levels of 37 different cytokines, chemokines and markers for angiogenesis and vascular injury were quantified by an electrochemiluminescence multiplex assay (V-PLEX Human Biomarker 40-Plex Kit of Meso Scale Discovery ^®). Correlations between individual biomarkers and the fecal calprotectin level were assessed using Spearman’s correlation coefficient (ρ).

Results

A highly significant positive correlation was observed between the pro-inflammatory serum cytokines IFN-γ and CRP and fecal calprotectin levels (P < 0.01). Moreover, fecal calprotectin levels showed a significant positive correlation with IL-6, TNF-β, SAA and IL-17A (P < 0.05).

Conclusion

We show that a positive correlation exists between multiple serum Th1- and Th17-associated cytokines and the fecal calprotectin level. These cytokines and CRP may serve as additional biomarkers for determining disease activity and evaluating treatment response in CD. Ultimately, this may result in more efficient treatment of active disease in CD patients and prevention of complications.

Unsuspected Small-Bowel Crohn's Disease in Elderly Patients Diagnosed by Video Capsule Endoscopy

Background

Video capsule endoscopy (VCE) is increasingly performed among the elderly for obscure bleeding. Our aim was to report on the utility of VCE to uncover unsuspected Crohn's disease (CD) in elderly patients.

Methods

Retrospective review of VCE performed in elderly patients (≥70 y) at a tertiary hospital (2010-2015). All underwent prior negative bidirectional endoscopies. CD diagnosis was based on consistent endoscopic findings, exclusion of other causes, and a Lewis endoscopic score (LS) > 790 (moderate-to-severe inflammation). Those with lower LS (350-790) required histological confirmation. Known IBD cases were excluded.

Results

197 VCE were performed (mean age 78; range 70-93). Main indications were iron deficiency anemia (IDA), occult GI bleeding (OGIB), chronic abdominal pain, or diarrhea. Eight (4.1%) were diagnosed as CD based on the aforementioned criteria. Fecal calprotectin (FCP) was elevated in 7/8 (mean 580 μg/g). Mean LS was 1824. Small-bowel CD detected by VCE led to a change in management in 4/8. One patient had capsule retention secondary to NSAID induced stricture, requiring surgical retrieval.

Conclusions

VCE can be safely performed in the elderly. A proportion of cases may have unsuspected small-bowel CD despite negative endoscopies. FCP was the best screening test. Diagnosis frequently changed management.

Peroxiredoxin 1 expression in active ulcerative colitis mucosa identified by proteome analysis and involvement of thioredoxin based on immunohistochemistry

Ulcerative colitis (UC) is a chronic, relapsing, inflammatory bowel disease, and patients with long-standing UC are at high risk of developing colorectal cancer as a typical case of the organ-specific chronic inflammation-carcinoma sequence. Interactions between epithelial and stromal cells and alterations in a variety of stromal microenvironments have been demonstrated to have important roles in the carcinogenesis of UC-associated carcinoma. Therefore, the identification of proteins in the inflammatory microenvironment is important not only in the epithelium, however also in the stroma of UC inflammatory foci. To identify proteins associated with UC-associated carcinoma, the present study used proteomic analysis with two-dimensional electrophoresis and mass spectrometry. Differentially expressed proteins were assessed between active and inactive UC biopsy specimens. Results were verified by immunohistochemistry. Peroxiredoxin 1 (PRDX1) was among the proteins identified to have increased expression in active compared with inactive UC. Immunohistochemical analysis indicated that the expression of both PRDX1 and thioredoxin (TRX) increased with increasing inflammation grade in epithelial cells in UC mucosal crypts. PRDX1-positive stromal cells in the lower half of the lamina propria increased along with colitis severity. Furthermore, the expression of both PRDX1 and TRX proteins was increased in UC-associated neoplastic lesions compared with normal mucosa. A stepwise increase in PRDX1 expression was clear with increasing tumor progression in UC-associated tumorigenesis. Since PRDX1 and TRX overexpression was a unique characteristic of UC activity and UC-associated neoplastic lesions, PRDX1 and TRX expression may reflect oxidative stress along with the severity of colitis activity and UC-associated tumorigenesis in patients with UC.

Intergenerational transfer of antibiotic-perturbed microbiota enhances colitis in susceptible mice

Antibiotic exposure in children has been associated with the risk of Inflammatory Bowel Disease (IBD). Since antibiotic use in children or in their pregnant mother can affect how the intestinal microbiome develops, we asked whether the transfer of an antibiotic-perturbed microbiota from mothers to their children could affect their risk of developing IBD. Here we demonstrate that germ-free adult pregnant mice inoculated with a gut microbial community shaped by antibiotic exposure transmitted their perturbed microbiota to their offspring with high fidelity. Without any direct or continued exposure to antibiotics, this dysbiotic microbiota in the offspring remained distinct from controls for at least 21 weeks. By using both IL-10-deficient and wild type mothers, we showed that both inoculum and genotype shape the microbiota populations in the offspring. Since IL10−/− mice are genetically susceptible to colitis, we could assess the risk due to maternal transmission of an antibiotic-perturbed microbiota. We found that the IL10−/− offspring that had received the perturbed gut microbiota developed markedly increased colitis. Taken together, our findings indicate that antibiotic exposure shaping the maternal gut microbiota has effects that extend to their offspring with both ecological and long-term disease consequences.

Detection of calprotectin in inflammatory bowel disease: Fecal and serum levels and immunohistochemical localization

The aim of the present study was to quantify calprotectin levels using an enzyme-linked immunosorbent assay (ELISA) and a point-of-care test (POCT) in patients with inflammatory bowel disease. Overall, 113 patients with ulcerative colitis (UC; 51 men and 62 women) and 42 patients with Crohn's disease (CD; 29 men and 13 women), who were scheduled to undergo a colonoscopy, were prospectively enrolled and scored endoscopically and clinically. An additional 96 healthy, age-matched subjects served as the normal controls. Feces and blood samples from the patients with UC and CD, and the normal controls were analyzed. These patients had received adequate medical treatment. The tissue distribution of calprotectin was investigated using immunohistochemistry. The fecal calprotectin levels, as measured using an ELISA, were correlated with the endoscopic and clinical disease activities and laboratory parameters, including serum levels of hemoglobin (Hb), albumin and C-reactive protein, and erythrocyte sedimentation rate, particularly among the patients with UC. The fecal Hb level was close to that of the fecal calprotectin level (r=0.57; P<0.0001). The fecal calprotectin level measured using an ELISA was well-correlated with the fecal calprotectin level measured using the POCT (r=0.81; P<0.0001), but was not correlated with the serum calprotectin level (r=0.1013; P=0.47). An immunohistochemical investigation revealed that patients with both UC and CD had higher neutrophil and monocyte/macrophage calprotectin-positive cell expression levels, compared with those in the normal controls. Fecal calprotectin was considered a reliable marker for disease activity, and the assessment of fecal calprotectin via POCT showed potential as a rapid and simple measurement in clinical settings.

Monitoring and detection of disease recurrence after resection for Crohn's disease: the role of non-invasive fecal biomarkers

Ileocolonoscopy is the gold standard for the diagnosis and assessment of postoperative recurrence in Crohn's disease (CD). Nevertheless, endoscopy is time-consuming and invasive. A minimally invasive and simple screening test would improve patient adherence to examination and provide greater clinical benefit. A number of fecal biomarkers have been evaluated for their utility for the diagnosis and monitoring of inflammatory bowel disease as alternative tests to endoscopy. Area covered: In this review, we focused on the utility of fecal biomarkers in the management of postoperative CD. Our major endeavor was to present an evidence-based assessment of the results of clinical trials on the available data. A literature search was conducted using the Medline. Expert commentary: Calprotectin and lactoferrin, both neutrophil-derived proteins, are the two most frequently used fecal biomarkers in clinical trials and practice. Several studies evaluated the role of these fecal biomarkers in patients with postoperative CD. These studies suggest that fecal calprotectin, and to a lesser degree lactoferrin, are useful in assessing endoscopic severity and in predicting future clinical recurrence after resection for CD. However, large scale, well-designed studies are necessary to rigorously evaluate the role of fecal biomarkers in postoperative CD.

Faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease: a prospective study

BACKGROUND

The value of faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease (CD) remains to be elucidated. This prospective study was to evaluate the utility of faecal biomarkers for detecting small intestinal inflammation.

METHODS

A total of 122 consecutive patients with a diagnosis of CD in the small intestine were screened for eligibility. Computed tomography enterography (CTE) was undertaken to evaluate small bowel inflammation followed by colonoscopy to confirm no large bowel involvement. Seventy eligible patients with inflammation confined to the small intestine were included. Faecal samples were collected for assaying calprotectin, lactoferrin and haemoglobin. For assessing the degree of small bowel inflammation, a semi-quantitative scoring system (CTE0, normal; CTE1, mild; CTE2, moderate; CTE3, severe) was applied.

RESULTS

The median calprotectin, lactoferrin and haemoglobin levels were significantly higher in patients with small bowel inflammation, CTE scores 1-3 (n = 42) versus 0 (n = 28): calprotectin, 330 versus 40 ng/ml, p < 0.0001; lactoferrin, 14 versus 3 ng/ml, p < 0.0001; haemoglobin, 29.5 versus 6.5 ng/ml, p = 0.005. There was a strong positive relationship between the faecal biomarkers and CTE score: calprotectin, p < 0.0001; lactoferrin, p < 0.0001; haemoglobin, p = 0.0004. A cutoff value of 140 ng/ml for calprotectin had a sensitivity of 69% and a specificity of 82% with an area under the receiver operating characteristic curve (AUC) of 0.82 to detect small bowel inflammation (CTE scores 1-3), while lactoferrin 6 ng/ml had a sensitivity of 69% and a specificity of 79% with an AUC of 0.83, and haemoglobin 9 ng/ml showed a sensitivity of 71% and a specificity of 39% with an AUC of 0.70.

CONCLUSIONS

Faecal calprotectin, lactoferrin, and to a lesser degree haemoglobin are relevant biomarkers for screening small bowel inflammation in CD patients without large bowel involvement. Further well-designed large-scale studies in this clinical setting should strengthen our findings.

Effect of faecal calprotectin assay variability on the management of inflammatory bowel disease and potential role of faecal S100A12

Aims

To prospectively evaluate whether between-assay variability of different faecal calprotectin (f-Cp) assays influences diagnostic accuracy for inflammatory bowel disease (IBD) in a cohort of patients with confirmed IBD and irritable bowel syndrome (IBS). To also evaluate the diagnostic accuracy of faecal S100A12 (f-S100A12) against f-Cp in the same patient cohort and assess whether f-S100A12 offers additional diagnostic value.

Methods

F-Cp using four commercially available f-Cp assays, f-S100A12 and blood biomarkers were measured in patients, recruited from the local IBD clinic, who had established IBS or active ulcerative colitis (UC) and Crohn’s disease (CD). Diagnostic sensitivities and specificities for each assay and biomarker were calculated and compared.

Results

Median f-Cp levels in all assays were significantly higher in UC (347–884 µg/g; n=28) and CD (377–838 µg/g; n=15) compared with IBS (6–27 µg/g; n=17). Sensitivities and specificities at 50 µg/g were 94%–100% and 82%–100%, respectively. Median f-S100A12 levels were significantly higher in UC (81.0 µg/g; IQR 38.3–159.8) and CD (47.2 µg/g; IQR 5.3–108.9) compared with IBS (0.7 µg/g; IQR 0.5–0.8). At 2.8 µg/g, f-S100A12 had a sensitivity of 97% and specificity of 94%. The blood biomarkers demonstrated sensitivities and specificities of 44%–63% and 80%–92%, respectively.

Conclusions

The diagnostic sensitivity of the calprotectin assays was similar despite inter-kit variability in absolute values. There is a need for f-Cp assay standardisation, but in its absence assay-specific cut-off values may optimise their diagnostic performance. F-S100A12 demonstrated comparable sensitivity and specificity to f-Cp and although a research tool at present, may have a future role to play in the diagnosis and management of these patients.

Modified Delphi Process for the Development of Choosing Wisely for Inflammatory Bowel Disease

BACKGROUND AND AIMS

The prevalence and incidence of inflammatory bowel disease (IBD) in North America is among the highest in the world and imparts substantial direct and indirect medical costs. The Choosing Wisely Campaign was launched in wide variety of medical specialties and disciplines to reduce unnecessary or harmful tests or treatment interventions.

METHODS

The Choosing Wisely list for IBD was developed by the Canadian IBD Network for Research and Growth in Quality Improvement (CINERGI) in collaboration with Crohn's and Colitis Canada (CCC) and the Canadian Association of Gastroenterology (CAG). Using a modified Delphi process, 5 recommendations were selected from an initial list of 30 statements at a face-to-face consensus meeting.

RESULTS

The 5 things physicians and patients should question: (1) Don't use steroids (e.g., prednisone) for maintenance therapy in IBD; (2) Don't use opioids long-term to manage abdominal pain in inflammatory bowel disease (IBD); (3) Don't unnecessarily prolong the course of intravenous corticosteroids in patients with acute severe ulcerative colitis (UC) in the absence of clinical response; (4) Don't initiate or escalate long-term medical therapies for the treatment of IBD based only on symptoms; and (5) Don't use abdominal computed tomography (CT) scan to assess IBD in the acute setting unless there is suspicion of a complication (obstruction, perforation, abscess) or a non-IBD etiology for abdominal symptoms.

CONCLUSIONS

The Choosing Wisely recommendations will foster patient-physician discussions to optimize IBD therapy, reduce adverse effects from testing and treatment, and reduce medical expenditure.

Low-FODMAP diet reduces irritable bowel symptoms in patients with inflammatory bowel disease

AIM

To investigate the effect of a low-FODMAP diet on irritable bowel syndrome (IBS)-like symptoms in patients with inflammatory bowel disease (IBD).

METHODS

This was a randomised controlled open-label trial of patients with IBD in remission or with mild-to-moderate disease and coexisting IBS-like symptoms (Rome III) randomly assigned to a Low-FODMAP diet (LFD) or a normal diet (ND) for 6 wk between June 2012 and December 2013. Patients completed the IBS symptom severity system (IBS-SSS) and short IBD quality of life questionnaire (SIBDQ) at weeks 0 and 6. The primary end-point was response rates (at least 50-point reduction) in IBS-SSS at week 6 between groups; secondary end-point was the impact on quality of life.

RESULTS

Eighty-nine patients, 67 (75%) women, median age 40, range 20-70 years were randomised: 44 to LFD group and 45 to ND, from which 78 patients completed the study period and were included in the final analysis (37 LFD and 41 ND). There was a significantly larger proportion of responders in the LFD group (n = 30, 81%) than in the ND group (n = 19, 46%); (OR = 5.30; 95%CI: 1.81-15.55, P < 0.01). At week 6, the LFD group showed a significantly lower median IBS-SSS (median 115; inter-quartile range [IQR] 33-169) than ND group (median 170, IQR 91-288), P = 0.02. Furthermore, the LFD group had a significantly greater increase in SIBDQ (median 60, IQR 51-65) than the ND group (median 50, IQR 39-60), P < 0.01.

CONCLUSION

In a prospective study, a low-FODMAP diet reduced IBS-like symptoms and increased quality of life in patients with IBD in remission.

Association of enteric parasitic infections with intestinal inflammation and permeability in asymptomatic infants of São Tomé Island

The cumulative effect of repeated asymptomatic enteric infections on intestinal barrier is not fully understood in infants. We aimed to evaluate the association between previous enteric parasitic infections and intestinal inflammation and permeability at 24-months of age, in asymptomatic infants of São Tomé Island. A subset of infants from a birth cohort, with intestinal parasite evaluations in at least four points of assessment, was eligible. Intestinal inflammatory response and permeability were assessed using fecal S100A12 and alpha-1-antitrypsin (A1AT), respectively. The cutoff <-1SD for weight-for-length and length-for-age was used to define wasting and stunting. Multivariable linear regression analysis explored if cumulative enteric parasitic infections explained variability of fecal biomarkers, after adjusting for potential confounders. Eighty infants were included. Giardia duodenalis and soil-transmitted helminths (STH) were the most frequent parasites. The median (interquartile range) levels were 2.87 μg/g (2.41-3.92) for S100A12 and 165.1 μg/g (66.0-275.6) for A1AT. Weak evidence of association was found between S100A12 levels and G. duodenalis (p = 0.080) and STH infections (p = 0.089), and between A1AT levels and parasitic infection of any etiology (p = 0.089), at 24-months of age. Significant associations between A1AT levels and wasting (p = 0.006) and stunting (p = 0.044) were found. Previous parasitic infections were not associated with fecal biomarkers at 24 months of age. To summarize, previous asymptomatic parasitic infections showed no association with intestinal barrier dysfunction. Notwithstanding, a tendency toward increased levels of the inflammatory biomarker was observed for current G. duodenalis and STH infections, and increased levels of the permeability biomarker were significantly associated with stunting and wasting.

[Fecal Calprotectin in Inflammatory Bowel Disease]

Inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis comprise conditions characterized by chronic, relapsing immune activation and inflammation within the gastrointestinal tract. Objective estimation of intestinal inflammation is the mainstay in the diagnosis and observation of IBD, but is primarily dependent on expensive and invasive procedures such as endoscopy. Therefore, a simple, noninvasive, inexpensive, and accurate test would be extremely important in clinical practice. Fecal calprotectin is a calcium-containing protein released into the lumen that is excreted in feces during acute and chronic inflammation. It is well-researched, noninvasive, and has high sensitivity and specificity for identification of inflammation in IBD. This review will focus on the use of fecal calprotectin to help diagnose, monitor, and determine treatment in IBD.

Accuracy of Faecal Calprotectin and Neutrophil Gelatinase B-associated Lipocalin in Evaluating Subclinical Inflammation in UlceRaTIVE Colitis-the ACERTIVE study

BACKGROUND AND AIMS

Mucosal healing and histological remission are different targets for patients with ulcerative colitis, but both rely on an invasive endoscopic procedure. This study aimed to assess faecal calprotectin and neutrophil gelatinase B-associated lipocalin as biomarkers for disease activity in asymptomatic ulcerative colitis patients.

METHODS

This was a multicentric cross-sectional study including 371 patients, who were classified according to their endoscopic and histological scores. These results were evaluated alongside the faecal levels of both biomarkers.

RESULTS

Macroscopic lesions [i.e. endoscopic Mayo score ≥1] were present in 28% of the patients, and 9% had active disease according to fht Ulcerative Colitis Endoscopic Index of Severity. Moreover, 21% presented with histological inflammation according to the Geboes index, whereas 15% and 5% presented with focal and diffuse basal plasmacytosis, respectively. The faecal levels of calprotectin and neutrophil gelatinase B-associated lipocalin were statistically higher for patients with endoscopic lesions and histological activity. A receiver operating characteristic-based analysis revealed that both biomarkers were able to indicate mucosal healing and histological remission with an acceptable probability, and cut-off levels of 150-250 μg/g for faecal calprotectin and 12 μg/g for neutrophil gelatinase B-associated lipocalin were proposed.

CONCLUSIONS

Faecal calprotectin and neutrophil gelatinase B-associated lipocalin levels are a valuable addition for assessment of disease activity in asymptomatic ulcerative colitis patients. Biological levels of the analysed biomarkers below the proposed thresholds can rule out the presence of macroscopic and microscopic lesions with a probability of 75-93%. However, caution should be applied whenever interpreting positive results, as these biomarkers present consistently low positive predictive values.

Neutrophils in ulcerative colitis: a review of selected biomarkers and their potential therapeutic implications

OBJECTIVES

This review article describes the role of neutrophils in mucosal injury and the resulting crypt abscesses characteristic of ulcerative colitis. We also review selected biomarkers for monitoring neutrophil presence and activity in the mucosa as well as their potential as therapeutic targets.

MATERIAL

We have collated and selectively reviewed data on the most prominent well-established and emerging neutrophil-related biomarkers and potential therapeutic targets (calprotectin, lactoferrin, CXCR1, CXCR2, MMP-9, NGAL, elafin, HNE, pANCAs, MPO, CD16, CD177, CD64, HNPs, SLPI and PTX3) in ulcerative colitis.

RESULTS

Systemic and intestinal neutrophil activity increases substantially in active ulcerative colitis, driving tissue damage and extra-intestinal manifestations. Calprotectin is a robust neutrophil and disease biomarker, and a few neutrophil-related targets are being clinically explored as therapeutic targets.

CONCLUSION

We propose that targeting neutrophils and their inflammatory mediators per se is an opportunity that should be explored to identify new effective medical therapies. The overall clinical goal for neutrophil-targeted therapy will be to modulate, but not completely silence, neutrophil activity, thereby abolishing the destructive inflammation with associated acute and chronic tissue damage without compromising host-defense.

Competition for Iron Between Host and Pathogen: A Structural Case Study on Helicobacter pylori

Helicobacter pylori (H. pylori) is a highly successful bacterial pathogen, which colonizes the stomach of more than half of the world's population. To colonize and survive in such an acidic and inhospitable niche, H. pylori cells have evolved complex mechanisms to acquire nutrients from human hosts, including iron, an essential nutrient for both the pathogens and host cells. However, human cells also utilize diverse strategies in withholding of irons to prevent the bacterial outgrowth. The competition for iron is the central battlefield between pathogen and host. This mini-review summarizes the updated scenarios of the battle for iron between H. pylori and human host from a structural biology perspective.

Serum Calprotectin: A Novel Diagnostic and Prognostic Marker in Inflammatory Bowel Diseases

OBJECTIVES

There is an unmet need for novel blood-based biomarkers that offer timely and accurate diagnostic and prognostic testing in inflammatory bowel diseases (IBD). We aimed to investigate the diagnostic and prognostic utility of serum calprotectin (SC) in IBD.

METHODS

A total of 171 patients (n=96 IBD, n=75 non-IBD) were prospectively recruited. A multi-biomarker model was derived using multivariable logistic regression analysis. Cox proportional hazards model was derived to assess the contribution of each variable to disease outcomes.

RESULTS

SC correlated strongly with current biomarkers, including fecal calprotectin (FC) (n=50, ρ=0.50, P=1.6 × 10-4). SC was the strongest individual predictor of IBD diagnosis (odds ratio (OR): 9.37 (95% confidence interval (CI): 2.82-34.68), P=4.00 × 10-4) compared with other markers (C-reactive protein (CRP): OR 8.52 (95% CI: 2.75-28.63), P=2.80 × 10-4); albumin: OR 6.12 (95% CI: 1.82-22.16), P=0.004). In a subset of 50 patients with paired SC and FC, the area under receiver operating characteristic discriminating IBD from controls was better for FC than for SC (0.99, (95% CI 0.87-1.00) and 0.87 (95% CI:0.78-0.97), respectively; P=0.01). At follow-up (median 342 days; interquartile range: 88-563), SC predicted treatment escalation and/or surgery in IBD (hazard ratio (HR) 2.7, 95% CI: 1.1-4.9), in particular Crohn's disease (CD) (HR 4.2, 95% CI 1.2-15.3). A model incorporating SC and either CRP or albumin has a positive likelihood ratio of 24.14 for IBD. At 1 year, our prognostic model can predict treatment escalation in IBD in 65% of cases (95% CI: 43-79%) and 80% (95% CI: 31-94%) in CD if ≥2 blood marker criteria are met.

CONCLUSIONS

A diagnostic and prognostic model that combines SC and other blood-based biomarkers accurately predicts the inflammatory burden in IBD and has the potential to predict disease and its outcomes. Our data warrant further detailed exploration and validation in large multicenter cohorts.

Histological Outcomes and Predictive Value of Faecal Markers in Moderately to Severely Active Ulcerative Colitis Patients Receiving Infliximab

BACKGROUND AND AIMS

Histological healing has emerged as a promising therapeutic goal in ulcerative colitis. This is especially important in the context of biological therapies. The objectives of the present study were to investigate the ability of infliximab to induce histological remission in ulcerative colitis [UC] patients and to explore the utility of faecal calprotectin and lactoferrin in predicting histological activity.

METHODS

Multi-centre, single-cohort, open-label, 52-week trial including moderately to severely biological-naïve UC patients receiving intravenous infliximab [5mg/kg]. The primary outcome was the proportion of patients with histological remission [Geboes index ≤ 3.0] after 8 weeks of treatment, scored by two independent pathologists.

RESULTS

Twenty patients were included. The rate of histological remission increased from 5% at baseline to 15% and 35% at Week 8 and Week 52, respectively. At Week 8, 40% of patients were in clinical remission [Mayo ≤ 2] and 45% achieved mucosal healing [Mayo endoscopy subscore 0-1]. At Week 52, 25% of patients had clinical, endoscopic and histological remission. Faecal calprotectin and lactoferrin showed the highest correlation with histological activity at Week 8 (area under the curve [AUC] 94%, p = 0.017; and 96%, p = 0.013, respectively) and both markers revealed an excellent positive predictive value for this outcome at this time point [100%, p = 0.017; and 94%, p = 0.013, respectively].

CONCLUSIONS

Infliximab was able to induce histological remission. There was a good agreement between histology and faecal biomarkers. Faecal calprotectin and lactoferrin were good predictors of histological remission. Our data support inclusion of histology as a treatment target complementary to endoscopy in clinical trials when evaluating therapeutic response in UC.

Noninvasive Testing for Mucosal Inflammation in Inflammatory Bowel Disease

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

Safety and Efficacy of Granulocyte/Monocyte Apheresis in Steroid-Dependent Active Ulcerative Colitis with Insufficient Response or Intolerance to Immunosuppressants and/or Biologics [the ART Trial]: 12-week Interim Results

BACKGROUND AND AIMS

Patients with active, steroid-dependent ulcerative colitis with insufficient response or intolerance to immunosuppressants and/or biologic therapies have limited treatment options. Adacolumn, a granulocyte/monocyte adsorptive apheresis device, has shown clinical benefit in these patients. This study aimed to provide additional clinical data regarding the safety and efficacy of Adacolumn in this patient subgroup.

METHODS

This single-arm, open-label, multicentre trial [ART] was conducted at 18 centres across the UK, France, and Germany. Eligible patients were 18-75 years old with moderate-to-severe, steroid-dependent active ulcerative colitis with insufficient response or intolerance to immunosuppressants and/or biologics. Patients received ≥ 5 weekly apheresis sessions with Adacolumn. The primary endpoint was clinical remission rate [clinical activity index ≤ 4] at Week 12.

RESULTS

In all, 86 patients were enrolled. At Week 12, 33/84 [39.3%] of patients in the intention-to-treat population achieved clinical remission, with 47/84 [56.0%] achieving a clinical response [clinical activity index reduction of ≥ 3]. Clinical remission was achieved in 30.0% of patients with previous immunosuppressant and biologic failure; steroid-free clinical remission and response were observed in 22.6% and 35.7% of these patients, respectively. Quality of life [Short Health Scale] significantly improved at Week 12 [p < 0.0001]. The majority of adverse events were of mild/moderate intensity.

CONCLUSIONS

At Week 12, Adacolumn provided significant clinical benefit in a large cohort of steroid-dependent ulcerative colitis patients with previous failure to immunosuppressant and/or biologic treatment, with a favourable safety profile. These results are consistent with previous studies and support Adacolumn use in this difficult-to-treat patient subgroup.

Koch's postulates, microbial dysbiosis and inflammatory bowel disease

Over the past 20 years, a growing amount of evidence supports the role of microbes and an imbalanced microbiota in inflammatory bowel disease (IBD). While many reviews have been written on the microbiota in IBD, few have considered how they fulfil the Koch's postulates. In this review, we consider how the Koch's postulates might be modified so that they can be fulfilled for polymicrobial diseases, and we discuss the progress made to date in fulfilling them.

Fecal calprotectin: its scope and utility in the management of inflammatory bowel disease

Gastrointestinal symptoms such as abdominal pain, dyspepsia, and diarrhea are relatively nonspecific and a common cause for seeking medical attention. To date, it is challenging for physicians to differentiate between functional and organic gastrointestinal conditions and it involves the use of serological and endoscopic techniques. Therefore, a simple, noninvasive, inexpensive, and effective test would be of utmost importance in clinical practice. Fecal calprotectin (FC) is considered to be a reliable biomarker that fulfills these criteria. FC can detect intestinal inflammation, and its level correlates well with macroscopic and histological inflammation as detected by colonoscopy and biopsies, respectively. FC has a decent diagnostic accuracy for differentiating organic diseases and functional disorders because of its excellent negative predictive value in ruling out inflammatory bowel disease (IBD) in symptomatic undiagnosed patients. There is accumulating evidence that FC has been effectively used to monitor the natural course of IBD, to predict relapse, and to see the response to treatment. This novel biomarker has the ability to assess mucosal healing (MH), which is a therapeutic goal in IBD management. A literature search was carried out using PubMed with the keywords FC, IBD, intestinal inflammation, and MH. In our review, we provide an overview of the utility and scope of FC as a biomarker in patients with IBD as well as undiagnosed patients with lower gastrointestinal symptoms.

Comparisons between myeloperoxidase, lactoferrin, calprotectin and lipocalin-2, as fecal biomarkers of intestinal inflammation in malnourished children

Fecal biomarkers have emerged as important tools to assess intestinal inflammation and enteropathy. The aim of this study was to investigate the correlations between the fecal markers, myeloperoxidase (MPO), lactoferrin (FL), calprotectin (FC) and lipocalin-2 (Lcn-2), and to compare differences by breastfeeding status as well as normalization by fecal protein or by fecal weight. Simultaneous, quantitative MPO, FL, FC and Lcn-2, levels were determined in frozen fecal specimens collected from 78 children (mean age 15.2 ± 5.3 months) in a case-control study of childhood malnutrition in Brazil. The biomarker concentrations were measured by enzymelinked immunosorbent assay. The correlations among all biomarkers were significant (P<0.01). There were stronger correlations of fecal MPO with fecal lactoferrin and calprotectin, with lower, but still highly significant correlations of all 3 inflammatory biomarkers with Lcn-2 likely because the latter may also reflect enterocyte damage as well as neutrophil presence. Furthermore, the biomarker results with protein normalized compared to simple fecal weight normalized values showed only a slightly better correlation suggesting that the added cost and time for protein normalization added little to carefully measured fecal weights as denominators. In conclusion, fecal MPO correlates tightly with fecal lactoferrin and calprotectin irrespective of breastfeeding status and provides a common, available biomarker for comparison of human and animal model studies.