Assessment of disease activity in ulcerative colitis by faecal calprotectin, a novel granulocyte marker protein

Review article: biological activity markers in inflammatory bowel disease

BACKGROUND

Traditionally, inflammatory bowel disease activity is assessed by clinical activity indices that measure clinical symptoms and endoscopic indices that measure endoscopic inflammation. Biological markers are a non-invasive way of objectively measuring inflammation and can play an adjunctive or primary role in the assessment of disease activity.

AIM

To review the data on biological markers for assessment of disease activity and prediction of relapse in inflammatory bowel disease.

METHODS

To collect relevant articles, a PubMed search was performed from 1980 to 2006 using following search terms in combination: inflammatory bowel disease, biomarkers, inflammation, disease activity, relapse, acute phase reactants cytokines, interleukins, adhesion molecules, integrins, calprotectin and lactoferrin.

RESULTS

Biological activity markers can be classified into serological, faecal and miscellaneous categories. Acute phase reactants levels correlate with disease activity and some can be used to help predict relapse. Cytokines and adhesion molecules are elevated in active disease inconsistently. Faecal markers are useful in assessment of disease activity and relapse.

CONCLUSIONS

Acute phase reactants and faecal markers are useful to assess the disease activity in clinical practice. More data are required on cytokines and adhesion molecules. C-reactive protein, erythrocyte sedimentation rate, interleukins and faecal markers may be useful in predicting a relapse.

Dietary synbiotics reduce cancer risk factors in polypectomized and colon cancer patients

BACKGROUND

Animal studies suggest that prebiotics and probiotics exert protective effects against tumor development in the colon, but human data supporting this suggestion are weak.

OBJECTIVE

The objective was to verify whether the prebiotic concept (selective interaction with colonic flora of nondigested carbohydrates) as induced by a synbiotic preparation-oligofructose-enriched inulin (SYN1) + Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis Bb12 (BB12)-is able to reduce the risk of colon cancer in humans.

DESIGN

The 12-wk randomized, double-blind, placebo-controlled trial of a synbiotic food composed of the prebiotic SYN1 and probiotics LGG and BB12 was conducted in 37 colon cancer patients and 43 polypectomized patients. Fecal and blood samples were obtained before, during, and after the intervention, and colorectal biopsy samples were obtained before and after the intervention. The effect of synbiotic consumption on a battery of intermediate bio-markers for colon cancer was examined.

RESULTS

Synbiotic intervention resulted in significant changes in fecal flora: Bifidobacterium and Lactobacillus increased and Clostridium perfringens decreased. The intervention significantly reduced colorectal proliferation and the capacity of fecal water to induce necrosis in colonic cells and improve epithelial barrier function in polypectomized patients. Genotoxicity assays of colonic biopsy samples indicated a decreased exposure to genotoxins in polypectomized patients at the end of the intervention period. Synbiotic consumption prevented an increased secretion of interleukin 2 by peripheral blood mononuclear cells in the polypectomized patients and increased the production of interferon gamma in the cancer patients.

CONCLUSIONS

Several colorectal cancer biomarkers can be altered favorably by synbiotic intervention.

Differential diagnosis between functional and organic intestinal disorders: Is there a role for non-invasive tests?

Abdominal pain and bowel habits alterations are common symptoms in the general population. The investigation to differentiate organic from functional bowel disorders represents a considerable burden both for patients and public health service. The selection of patients who should undergo endoscopic and/or radiological procedures is one of the key points of the diagnostic process, which should avoid the abuse of invasive and expensive tests as well as the underestimation of potentially harmful diseases. Over the coming years, clinicians and researchers will be challenged to develop strategies to increase the patient’s compliance and to reduce the economic and social costs of the intestinal diseases.

Fecal calprotectin in first-degree relatives of patients with ulcerative colitis

OBJECTIVES

The pathogenesis of inflammatory bowel disease seems to depend on the combination of genetic and environmental factors. To evaluate genetic susceptibility, one approach is to search for specific markers in apparently unaffected family members of patients. Our aim was to evaluate fecal calprotectin concentrations (FCCs) in first-degree relatives of patients with ulcerative colitis (UC).

PATIENTS

Fifty-five patients with UC and 167 healthy first-degree relatives were recruited; 38 of the patients' spouses were also enrolled. One hundred fifty healthy subjects participated as the control group.

METHODS

FCCs were determined by ELISA. FCCs were compared among the groups by Kruskal-Wallis analysis of variance (ANOVA) test followed by Mann-Whitney U test.

RESULTS

Significantly greater FCCs were found in first-degree relatives of patients with UC (76.0 [34.7-129.6] microg/g) as compared with controls (31.6 [17.0-45.0]) (P < 0.0001). Fecal calprotectin levels in patients with UC (256.0 [153.0-356.0] microg/g) were significantly higher as compared with first-degree relatives, spouses (43.8 [18.6-89.0] microg/g), and controls (P < 0.0001 for all comparisons). FCC of relatives was significantly higher than FCC of spouses (P = 0.01). FCC of spouses had a significantly higher FCC with respect to controls (P = 0.01).

CONCLUSIONS

First-degree relatives of patients with UC had greater FCC values and could have a subclinical intestinal inflammation. It needs to be clarified if this finding is the consequence of genetic predisposition, of environmental factors, or the interaction of both, and if relatives with high FCC have a greater risk of developing the disease.

Role of fecal calprotectin as a biomarker of intestinal inflammation in inflammatory bowel disease

Calprotectin is an abundant neutrophil protein found in both plasma and stool that is markedly elevated in infectious and inflammatory conditions, including inflammatory bowel disease (IBD). We conducted a systematic review of the published literature regarding fecal calprotectin to evaluate its potential as a noninvasive marker of neutrophilic intestinal inflammation. Reference ranges for fecal calprotectin have been established in healthy adults and children, and elevated concentrations of fecal calprotectin have been demonstrated in numerous studies of patients with IBD. Fecal calprotectin correlates well with histological inflammation as detected by colonoscopy with biopsies and has been shown successfully to predict relapses and detect pouchitis in patients with IBD. Fecal calprotectin has been shown to consistently differentiate IBD from irritable bowel syndrome because it has excellent negative predictive value in ruling out IBD in undiagnosed, symptomatic patients. Fecal calprotectin also may be useful in determining whether clinical symptoms in patients with known IBD are caused by disease flares or noninflammatory complications/underlying irritable bowel syndrome and in providing objective evidence of response to treatment. Although more studies are needed to define fully the role of fecal calprotectin, convincing studies and growing clinical experience point to an expanded role in the diagnosis and management of IBD.

Mucosal features and granulocyte-monocyte-apheresis in steroid-dependent/refractory ulcerative colitis

BACKGROUND

Mucosa-infiltrated granulocyte neutrophils are an early characteristic of inflammation and the main histological feature of active ulcerative colitis. Mucosal healing has recently been indicated as an important tool in the evaluation of response to treatment. While several studies have stressed the efficacy of granulocyte-monocyte-apheresis in inducing clinical remission in active ulcerative colitis, few data are available on mucosal features.

AIM

Aim of this study was to assess the effects of granulocyte-monocyte-apheresis on clinical and mucosal features in patients with ulcerative colitis, dependent upon or refractory to steroids.

MATERIAL AND METHODS

From April 2004 to April 2005, 12 patients (5 females, 7 males, mean age 49 years, range 33-71 years), with mild-moderate ulcerative colitis (six left colitis, six pancolitis) dependent/refractory upon steroids were enrolled. Each patient was treated for a 5-week period with five cycles of granulocyte-monocyte-apheresis. Patients were evaluated at baseline and 1 week after the last apheresis by means of Global Physician Assessment, quality of life features, laboratory tests (erythrocyte sedimentation rate, CRP, full blood count, faecal calprotectine), endoscopy and histology.

RESULTS

At week 6 of follow-up, complete mucosal healing was observed in 3 out of 12 patients, partial mucosal healing in 8 patients and no change in 1 patient. Clinical response was complete in 8 out of 12 patients.

CONCLUSIONS

These data suggest that granulocyte-monocyte-apheresis induces an improvement both in clinical and mucosal lesions in steroid-dependent/refractory ulcerative colitis. Of note, the reduction in granulocyte infiltration and the improvement in mucosal lesions are accompanied by a reduction in faecal calprotectine.

Repeat planar white cell scanning to monitor short-term therapy of active inflammatory bowel disease: a methodological study and comparison with clinical scores and novel inflammatory markers

OBJECTIVES

Radiolabelled white cell scans provide non-invasive quantification of inflammatory activity. Clinical activity scores measure severity of disease but are partly subjective. White cell scans may provide a suitable method of monitoring the treatment response of active inflammatory bowel disease.

METHODS

Ten subjects with active ulcerative colitis and 13 subjects with active Crohn's disease were recruited. White cell scans were carried out before and 2 weeks after treatment. Prior to each scan, activity scores for ulcerative colitis or Crohn's disease were calculated and serum and faecal tumour necrosis factor-alpha and calprotectin measured. White cell scan activity at 1 h was calculated by using a validated visual grading system.

RESULTS

Following anti-inflammatory treatment, 70% of white cell scans improved, 17% remained unchanged and 13% deteriorated. In the ulcerative colitis subgroup subjects there was modest agreement for change in scan score and activity scores. In the Crohn's disease subjects there was better agreement between change of white cell scan score and clinical scores. Planar white cell scans correlated with the van Hees activity index (r=0.68, P=0.002) and faecal calprotectin (r=0.58, P=0.0003). Changes in planar white cell scans correlated with changes in serum calprotectin (r=0.45, P=0.05).

CONCLUSION

Non-invasive white cell scanning is a feasible and objective method to monitor the anti-inflammatory efficacy of treatments for active inflammatory bowel disease.

The functionality and reliability of an Internet interface for assessments of endoscopic still images and video clips: distributed research in gastroenterology

BACKGROUND

Validation studies of medical images are required before the general use of new imaging techniques, and they necessitate a substantial number of observers. Multicenter studies are desirable but the logistic challenges are considerable.

OBJECTIVE

The aim of the present study was to develop and test the functionality and reliability of an Internet interface for distributed evaluation of endoscopic still images and video clips.

DESIGN

An Internet site for assessment of endoscopic still images and video clips was developed. To avoid limitations of the bandwidth, a solution was developed to launch and score high-quality video clips on digital video disks (DVDs) from the Internet interface.

SETTING

Fifty-five observers were enrolled in the randomized, prospective multicenter study of still images. The feasibility study of video clips included 7 observers.

PATIENTS

Four patients presenting with various degree of ulcerative colitis, ranging from normal to severe, were included.

MAIN OUTCOME MEASUREMENTS

We tested the reliability of the interface by dual-image assessment, as well as the feasibility of Internet assessment of endoscopic images. We physically distributed high-quality DVD video footage.

RESULTS

We recorded 2084 assessments of endoscopic still images and 35 assessments of video clips. The reliability of the Internet interface was confirmed by adequate repeatability and intraobserver agreement of the assessments. Video clips running from a DVD were also successfully shown on the Internet interface. Thus, high-quality video may be assessed independently of the Internet bandwidth.

CONCLUSIONS

The present Internet-based tool is functional, efficient, and reliable for high-volume assessment of endoscopic images and video clips.

Faecal calprotectin in children with chronic gastrointestinal symptoms

AIMS

Faecal calprotectin, a neutrophil cytosolic protein, is raised in inflammatory bowel disease. We assessed this investigation in evaluating children with chronic intestinal symptoms.

METHODS

Stool samples from 100 children aged 5-17 years (referrals to the regional paediatric gastroenterology service) were tested using a commercially available kit.

RESULTS

Calprotectin was higher in inflammatory bowel disease than normal children (p<0.0001) or in those with functional constipation (p<0.0001). The overall specificity for organic bowel disorders was 85%. Calprotectin correlated with C-reactive protein in inflammatory bowel disease (p=0.001), and clinical disease activity in ulcerative colitis (p=0.017), but not with disease activity in Crohn's disease.

CONCLUSION

Raised faecal calprotectin should prompt further assessment in children with chronic intestinal symptoms, since an organic bowel disorder is likely. However, calprotectin cannot be regarded as a specific test for idiopathic inflammatory bowel disease.

Technology insight: calprotectin, lactoferrin and nitric oxide as novel markers of inflammatory bowel disease

Distinguishing patients with inflammatory bowel disease from those with irritable bowel syndrome can be difficult. A simple and reliable test that detects intestinal inflammation would therefore be very useful in the clinic. If such a test parameter correlated with the intensity of the inflammatory reaction it could also be used to monitor disease activity. Calprotectin, lactoferrin and nitric oxide are produced and released locally in much greater quantities in the inflamed gut than in the noninflamed gut. These compounds can be readily measured in fecal samples (calprotectin and lactoferrin) or directly in the intestinal lumen (nitric oxide gas). Here, we discuss what is known about these markers, how they could be used in clinical practice and how they can complement existing techniques used for the diagnosis and monitoring of inflammatory bowel disease.

Faecal calprotectin in the assessment of Crohn's disease activity

BACKGROUND

Clinical and laboratory assessment of activity in Crohn's disease (CD) correlate poorly with endoscopic findings. Calprotectin is a calcium-binding protein abundant in neutrophil cytosol, and extremely stable in faeces. Faecal calprotectin (FC) is an excellent surrogate marker of neutrophil influx into the bowel lumen.

AIM

To assess whether FC concentration from a spot stool sample reliably detects active inflammation in patients with CD.

DESIGN

Cross-sectional comparative study.

METHODS

Subjects had a previously confirmed diagnosis of CD and were suspected on clinical grounds to be in the midst of a relapse. Thirty-five entered the study; they underwent radiolabelled white cell scanning (WCS) and had a stool sample collected for calprotectin measurement on the same day. A Crohn's disease activity index (CDAI) was also calculated for each. The WCS scans were scored at six standard sites to give a mean total, 'extent', 'severity' and 'combined extent and severity' scores.

RESULTS

FC was significantly and positively correlated with mean total (r = 0.73, p < 0.001), 'extent' (r = 0.71, p < 0.001), 'severity' (r = 0.64, p < 0.001) and combined 'extent and severity' WCS scores (r = 0.71, p < 0.001). A cut-off of faecal calprotectin > 100 microg/g gave a sensitivity of 80%, specificity of 67%, positive predictive value of 87% and a negative predictive value of 64% in identifying those with and without any inflammation on WCS. There was, however, no significant correlation between CDAI and mean total WCS score (r = 0.21, p = 0.24), nor between CDAI and FC (r = 0.33, p = 0.06).

DISCUSSION

While the CDAI does not accurately reflect inflammatory activity in CD, a one-off FC reliably detects the presence or absence of intestinal inflammation in adult patients with CD, compared to WCS.

Image documentation of endoscopic findings in ulcerative colitis: photographs or video clips?

BACKGROUND

Previous studies have shown deficiencies in the endoscopy reports and substantial interobserver variation in the assessments of endoscopic findings. The aim of this study was to determine how to perform systematic digital image documentation in ulcerative colitis and to evaluate if mucosal inflammation is assessed equally on a still image and on a video clip.

METHODS

Eighteen video clips and their corresponding photographs that visualize different severities of ulcerative colitis were shown in randomized order to 20 experienced endoscopists. They assessed the mucosal inflammation of each image twice on a visual analog scale. Three comparisons were performed between the video clips, the photographs, and the video clips to the photographs, respectively.

RESULTS

The mean score of the inflammation of the video clips at tape 1 and 2 was 4.74: 95% confidence interval (CI)[4.41, 5.08] and 4.90: 95% CI[4.56, 5.24), respectively, and of the photographs 4.53: 95% CI[4.19, 4.88] and 4.43: 95% CI[4.09, 4.77], respectively. The first answer explains 83% of the variation in the second answer for all comparisons, and the agreement index ranged from 0.38 to 0.42.

CONCLUSIONS

The mucosal inflammation might be documented nearly as well with a still image as on a video clip. Systematic use of still images probably improves the endoscopy reports by adding more objective information about the mucosal inflammation.

Colorectal inflammation is well predicted by fecal calprotectin in children with gastrointestinal symptoms

OBJECTIVES

The protein calprotectin is mainly derived from neutrophils. Increased fecal excretion of calprotectin has been reported in inflammatory bowel disease. The recommended cut-off level in adults (<50 microg/g feces) seems to be applicable in children aged 4 to 17 years. The aim of this study was to evaluate the use of fecal calprotectin to detect colorectal inflammation in children with gastrointestinal symptoms.

METHODS

We obtained stool samples on thirty-six children with gastrointestinal symptoms and suspected inflammation of the colon before they underwent colonoscopy. The samples were examined with an improved fecal calprotectin enzyme-linked immunosorbent assay method (Calprest, Eurospital). The results were correlated with the histopathologic findings in the colon.

RESULTS

In children with colorectal inflammation (n = 22) the median fecal calprotectin concentration was 349 microg/g (range, 15.4-1860 microg/g). The most common diagnosis in this group was inflammatory bowel disease. Median fecal calprotectin was 16.5 microg/g (range, 5.0-65 microg/g) in children with no inflammation (n = 14). When <50 microg/g was used as upper reference limit the fecal calprotectin test had a sensitivity of 95%, specificity 93%, positive predictive value 95% and negative predictive value 93% to detect colorectal inflammation.

CONCLUSIONS

The improved fecal calprotectin enzyme-linked immunosorbent assay is a simple test with potential use in children. Increased fecal calprotectin strongly predicted the presence of colorectal inflammation in children with gastrointestinal symptoms. Fecal calprotectin can be used to select patients who should undergo diagnostic colonoscopy for investigation of colorectal inflammation, including inflammatory bowel disease.

An acute stressor enhances sensitivity to a chemical irritant and increases 51CrEDTA permeability of the colon in adult rats

We investigated the effect of prior acute stress on colonic permeability induced by a chemical irritant known to induce symptoms similar to inflammatory bowel disease in rodents. Adult male rats (n = 12) were stressed by a single session of ten unpredictable, uncontrollable foot shocks, and half were home cage controls (n = 12). Twenty-nine days later, half of each treatment group was exposed to 4% DSS (dextran sulphate sodium) solution in their drinking water for 48 hours while half received pure water over two periods separated by 17 days. After food deprivation overnight and light isoflurane anaesthesia the following morning, the animals were given a colonic infusion of 2000 nCi (nanocurie) 51CrEDTA (51Cr-labelled ethylenediaminetetraacetic acid) and then placed individually in metabolic cages for a six hours continuous urine collection. Radioactivity in urine was measured by a gamma counter and percentage recovery of 51CrEDTA calculated as an indicator of colonic mucosal permeability. Results concluded that pre-shocked animals exposed to DSS showed significantly higher mucosal permeability than the pre-shocked animals given water, and the non-shocked animals given either DSS or water. Pre-shock in combination with two exposures to a chemical irritant separated by 17 days had a pronounced effect on colonic permeability, indicating that stress should be considered a possible initiating or contributory factor to increased intestinal permeability related to a mucosal challenge.

Stool decay-accelerating factor as a marker for monitoring the disease activity during leukocyte apheresis therapy in patients with refractory ulcerative colitis

BACKGROUND AND AIMS

We have shown previously that concentrations of stool decay-accelerating factor (DAF; CD55), a complement regulatory protein, in patients with ulcerative colitis (UC) are increased in relation to the severity of the colonic mucosal inflammation. In the present study, we evaluated the usefulness of stool DAF as a marker for monitoring disease activity in patients with steroid-resistant active UC being treated with leukocyte apheresis performed with a centrifugal cell separator.

METHODS

Twenty-one patients with active and steroid-resistant UC were treated with leukocyte apheresis once a week for 4 weeks, and stool DAF concentrations were determined weekly by immunoassay.

RESULTS

After treatment, 11 (52%) of the 21 UC patients went into remission. Stool DAF concentrations decreased promptly and steadily in the responsive group. The difference reached statistical significance as soon as after the second apheresis session (P < 0.003), compared with values before the therapy and corresponding values in the non-responsive group (P = 0.024). The reduction in stool DAF concentrations after the second apheresis session was significantly greater in the responsive group (median 90%, range 22-90%) than in the non-responsive group (median -13%, range -307-94%) (P = 0.008). Hematological tests, that is, white blood cell (WBC) count and C-reactive protein, declined significantly during the apheresis therapy, but not in relation to therapeutic response.

CONCLUSION

Stool DAF concentration is a useful marker in the clinical response of UC patients to treatment with leukocyte apheresis.

Clinical Assessment of Disease Activity for Canine Inflammatory Bowel Disease

Clinical indices, consisting of gastrointestinal signs and laboratory parameters, are widely used for assessing disease activity in human inflammatory bowel disease (IBD). The development of a standardized scoring index for use in dogs with IBD would be useful in the management of clinical cases, both at diagnosis and in response to medical therapy. This review provides a synopsis of current strategies used to assess IBD activity in humans and companion animals. The clinical application of a simple scoring index (e.g., canine IBD activity index [CIBDAI]) for measurement of canine IBD activity is also reviewed.

Faecal calprotectin and lactoferrin as markers of acute radiation proctitis: a pilot study of eight stool markers

BACKGROUND

Non-invasive diagnostic tools to evaluate the severity of acute, radiation-induced proctitis are not readily available. The faecal excretion of eight markers of gut inflammation was therefore examined. Five proteins and three lipid derivates were analysed in sequential stool samples taken before and during radiation therapy.

METHODS

Stool samples from 15 patients with prostate cancer scheduled for radiation therapy were examined. Pretreatment and in-treatment samples (2nd and 6th weeks) were measured by enzyme-linked immunosorbent assay (ELISA) (calprotectin, lactoferrin, transferrin, leukotriene B4, prostaglandin E2, thromboxane B2 and TNF alpha) or nephelometry (alpha 1-antitrypsin).

RESULTS

Calprotectin and lactoferrin concentrations increased significantly during radiation treatment (P = 0.0005 and P = 0.019). Transferrin was detected in only 9 out of 45 samples. There were no changes in tumour necrosis factor alpha (TNF alpha), leukotriene B4, prostaglandin E2 and thromboxane B2 during treatment. alpha 1-antitrypsin could not be detected in any sample.

CONCLUSIONS

This study indicates that faecal calprotectin and lactoferrin concentrations could be markers of acute, radiation-induced proctitis. Patient compliance and stability of the markers make this a promising method for clinical research. Eicosanoids could be measured in stool samples, but the concentrations did not increase with increasing radiation dose.

Intestinal inflammation is a frequent feature of cystic fibrosis and is reduced by probiotic administration

AIMS

To assess the incidence of intestinal inflammation in children with cystic fibrosis and to investigate whether probiotics decrease it.

STUDY DESIGN

In this two-phase, controlled, prospective study, faecal calprotectin was measured by enzyme-linked immunosorbent assay in 30 children with cystic fibrosis, 30 healthy controls and 15 children with active inflammatory bowel disease. Ten children with cystic fibrosis received Lactobacillus GG, and faecal calprotectin was re-measured 4 weeks later. Rectal nitric oxide production was measured with the rectal dialysis bag technique in 20 children with cystic fibrosis, 20 healthy controls and 15 children with inflammatory bowel disease. Five children with cystic fibrosis received Lactobacillus GG and nitric oxide was re-measured 4 weeks later.

RESULTS

Mean faecal calprotectin was significantly higher in the two groups of patients than in controls. Abnormal values were detected in 27 of 30 cystic fibrosis and in 15 of 15 inflammatory bowel disease children. Also mean nitric oxide production was increased in both group of patients, and abnormal values were detected in 19 of 20 cystic fibrosis and in 15 of 15 inflammatory bowel disease children. Calprotectin and nitric oxide concentrations were reduced after probiotics administration.

CONCLUSIONS

Intestinal inflammation is a major feature of cystic fibrosis and is reduced by probiotics. The latter finding suggests that intestinal microflora play a major role in intestinal inflammation in cystic fibrosis children.

Diagnostic accuracy of faecal calprotectin estimation in prediction of abnormal small bowel radiology

BACKGROUND

[corrected] Patients being investigated for symptoms of abdominal pain, diarrhoea and or weight loss often undergo small bowel radiology as part of their diagnostic workup mainly to exclude inflammatory bowel disease.

AIM

To assess and compare the utility of a single faecal calprotectin estimation to barium follow through as well as conventional inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein in exclusion of intestinal inflammation.

METHODS

Seventy-three consecutive cases undergoing barium follow through for investigation of symptoms of diarrhoea and or abdominal pain with or without weight loss were studied. The control group comprised 25 cases with known active Crohn's disease (positive controls), 26 normal healthy volunteers (negative controls) and 25 cases of irritable bowel syndrome diagnosed by Rome II criteria. Symptoms, erythrocyte sedimentation rate and C-reactive protein were recorded at recruitment and a single stool sample assayed for calprotectin within 7 days prior to or after barium follow through.

RESULTS

The median calprotectin value in the active Crohn's group, irritable bowel syndrome group and normal volunteers was 227 microg/g of stool, 19 and 10 microg/g respectively (P < 0.0001). A faecal calprotectin above a cut-off value of 60 microg/g was able to predict all nine cases with an abnormal barium follow through as well as all six cases with a normal barium follow through but with organic intestinal disease. The negative predictive value of a single calprotectin result below 60 microg/g of stool was 100% compared with 91% each for erythrocyte sedimentation rate > 10 mm and C-reactive protein > 6 mg/L and 84% for a combination of erythrocyte sedimentation rate and C-reactive protein in predicting absence of organic intestinal disease.

CONCLUSION

A single stool calprotectin value < 60 microg/g of stool obviates the need for further barium radiology of the small bowel, is more accurate than measurement of erythrocyte sedimentation rate or C-reactive protein and effectively excludes Crohn's disease or non-functional gastrointestinal disease.

The effects of postnatal maternal separation on stress responsivity and experimentally induced colitis in adult rats

In this study, we investigated the effects of three neonatal conditions on adult corticosterone (CORT) levels, acoustic startle responses (ASRs), and vulnerability to colitis induced by dextran sulfate sodium (DSS) and how these early manipulations might interact with a brief stress exposure in adulthood on the same measures. Infant animals were subjected daily to either 180-min maternal separation [prolonged maternal separation (LMS)], 10-min maternal separation [brief maternal separation (BMS)], or nonhandling (NH) conditions during postnatal days 1-14. As adults, half of the animals were exposed to a series of 10 uncontrollable foot shocks. Animals were tested for CORT levels prior to and 10 days following shock/nonshock procedures before being tested for ASRs. Finally, all animals were exposed to 4% DSS in their drinking water for 6 days. LMS animals showed enhanced vulnerability to DSS-induced colitis when previously exposed to shock and enhanced stress reactivity responses as shown by elevated startle and CORT levels. Among the nonshocked animals, NH animals showed most colonic damage. Taken together, the results support previous findings suggesting that BMS has a protective effect on adult stress exposure. Additionally, BMS protects the animals from chemically induced colitis. The NH condition has clearly an effect on sensitizing mucosal response to DSS exposure.

Bowel inflammation as measured by fecal calprotectin: a link between lifestyle factors and colorectal cancer risk

The mechanisms by which the lifestyle risk factors obesity, physical inactivity, and low fiber intake predispose to colorectal cancer (CRC) are unclear. Chronic bowel inflammation predisposes to malignancy in cases of inflammatory bowel disease. Many lifestyle risk factors for CRC are associated with evidence of systemic inflammation as indicated by circulating levels of C-reactive protein (CRP), but it is unknown how this relates to inflammation at tissue level. Little is known about the degree of bowel inflammation in general population and the factors that affect it. Therefore, we aimed to assess the relation of levels of bowel inflammation in the general population and lifestyle risk factors for CRC, and to additionally assess whether these associations, if present, were attenuated by controlling for evidence of systemic inflammation. Average CRC risk subjects (320) of either sex aged 50-70 were recruited in South London. A stool sample was provided for calprotectin measurement (a marker of bowel inflammation), serum for CRP, and a detailed dietary and lifestyle questionnaire completed. There was a significant positive relationship between fecal calprotectin and increasing age (P = 0.002), obesity (P = 0.04), physical inactivity (P = 0.01), and an inverse relationship with fiber intake (P = 0.02) and vegetable consumption (P = 0.04). The relationship with obesity was attenuated by controlling for serum CRP. Fecal calprotectin levels are associated with lifestyle risk factors for colorectal cancer. Low-level asymptomatic bowel inflammation may be the link between lifestyle and the pathogenesis of CRC, and circulating proinflammatory cytokines may be part of the mechanism for this link.

Inter-observer agreement in the assessment of endoscopic findings in ulcerative colitis

Background

Endoscopic findings are essential in evaluating the disease activity in ulcerative colitis. The aim of this study was to evaluate how endoscopists assess individual endoscopic features of mucosal inflammation in ulcerative colitis, the inter-observer agreement, and the importance of the observers' experience.

Methods

Five video clips of ulcerative colitis were shown to a group of experienced and a group of inexperienced endoscopists. Both groups were asked to assess eight endoscopic features and the overall mucosal inflammation on a visual analogue scale. The following statistical analyses were used; Contingency tables analysis, kappa analysis, analysis of variance, Pearson linear correlation analysis, general linear models, and agreement analysis. All tests were carried out two-tailed, with a significance level of 5%.

Results

The inter-observer agreement ranged from very good to moderate in the experienced group and from very good to fair in the inexperienced group. There was a significantly better inter-observer agreement in the experienced group in the rating of 6 out of 9 features (p < 0.05). The experienced and inexperienced endoscopists scored the "ulcerations" significantly different. (p = 0.05). The inter-observer variation of the mean score of "erosions", "ulcerations" and endoscopic activity index in mild disease, and the scoring of "erythema" and "oedema" in moderate-severe disease was significantly higher in the inexperienced group.

A correlation was seen between all the observed endoscopic features in both groups of endoscopists. Among experienced endoscopists, a set of four endoscopic variables ("Vascular pattern", "Erosions", "Ulcerations" and Friability") explained 92% of the variation in EAI. By including "Granularity" in these set 91% of the variation in EAI was explained in the group of inexperienced endoscopists.

Conclusion

The inter-observer agreement in the rating of endoscopic features characterising ulcerative colitis is satisfactory in both groups of endoscopists but significantly higher in the experienced group. The difference in the mean score between the two groups is only significant for "ulcerations". The endoscopic variables "Vascular pattern", "Erosions", "Ulcerations" and Friability" explained the overall endoscopic activity index. Even though the present result is quite satisfactory, there is a potential of improvement. Improved grading systems might contribute to improve the consistency of endoscopic descriptions.

Increased expression of minichromosome maintenance protein 2 in active inflammatory bowel disease

OBJECTIVE

Minichromosome maintenance protein 2 (Mcm2) is an accurate indicator of cell cycle entry in tissue samples, but its expression in inflammatory bowel disease (IBD) has not previously been investigated. We have used immunohistochemistry to assess the expression of Mcm2, in comparison to the existing proliferation marker Ki-67, in active IBD and IBD without inflammatory activity.

MATERIALS AND METHODS

For this experimental study, sections from colonic biopsy and resection specimens of 48 patients with IBD (5 inactive/quiescent Crohn's disease (CD), 13 active CD, 19 inactive/quiescent ulcerative colitis (UC) and 11 active UC) and 15 normal controls were immunostained with antibodies to Mcm2 and Ki-67. The percentage of immunopositive epithelial nuclei was determined by calculating a labelling index (LI) for entire glands and for gland thirds (superficial, middle and basal).

RESULTS

The Mcm2 LI was significantly increased in the superficial third of glands in active vs. inactive/quiescent UC (P < 0.0001) and active vs. inactive/quiescent CD (P = 0.001). The Mcm2 LI was significantly greater than the Ki-67 LI in active IBD, both in entire glands (P < 0.0001) and in the superficial third of glands (UC, P = 0.001; CD, P = 0.0002). Mcm2 LIs for entire glands were significantly higher in UC (all cases) compared to CD (all cases) (P = 0.032).

CONCLUSIONS

There is increased cell cycle entry, as indicated by expression of Mcm2 and to a lesser extent Ki-67, in the superficial third of colonic glands in active IBD compared to inactive/quiescent IBD. Detection of Mcm2 may contribute to improved histological assessment of small tissue biopsies and may enable the development of a direct stool-based test for detection of active IBD and potentially for assessment of disease activity.

Role of faecal calprotectin as non-invasive marker of intestinal inflammation

BACKGROUND/AIM

Faecal calprotectin, a neutrophil granulocyte cytosol protein, is considered a promising marker of intestinal inflammation. We assessed and compared the faecal calprotectin concentration in patients with organic and functional chronic intestinal disorders.

PATIENTS AND METHODS

The study was carried out, using a commercially available ELISA test, measuring calprotectin in stool samples collected from 131 patients with inflammatory bowel diseases, 26 with intestinal neoplasms, 48 with irritable bowel syndrome and 34 healthy subjects.

RESULTS

Median faecal calprotectin was significantly increased in Crohn's disease (231 microg/g, 95% confidence interval (CI) 110-353 microg/g), ulcerative colitis (167 microg/g, 95% CI 59-276 microg/g), and neoplasms (105 microg/g, 95% CI 0-272 microg/g), whereas normal values were found in patients with irritable bowel syndrome (22 microg/g, 95% CI 9-35 microg/g) and in healthy subjects (11 microg/g, 95% CI 3-18 microg/g). A positive correlation was observed with clinical activity scores in Crohn's disease and ulcerative colitis. In both groups, patients with clinically active disease showed higher calprotectin levels than those observed in patients with quiescent disease (405 microg/g, 95% CI 200-610 microg/g vs. 213 microg/g, 95% CI 85-341 microg/g in CD patients, p<0.05, and 327 microg/g, 95% CI 104-550 microg/g vs. 123 microg/g, 95% CI 40-206 microg/g in UC patients, p<0.001).

CONCLUSIONS

Faecal calprotectin appears to be a promising and non-invasive biomarker of intestinal inflammation. If these findings are confirmed, it may provide a useful test for the diagnosis and follow up of inflammatory bowel diseases.

Emerging role of calprotectin in gastroenterology

Calprotectin is a calcium and zinc binding protein of the S100 family derived predominantly from neutrophils and monocytes. It is detectable in body fluids and tissue samples and is emerging as a valuable marker in the diagnosis, and the monitoring and determining of the prognosis of commonly encountered gastroenterological conditions. Fecal calprotectin, in particular, has for a long time been regarded as a promising marker of gastrointestinal pathology and has now been established as a routine test in Norway and at several centers in the UK.

Subclinical intestinal inflammation: an inherited abnormality in Crohn's disease relatives?

BACKGROUND & AIMS

One approach to unraveling the genetics of complex inherited disease, such as Crohn's disease, is to search for subclinical disease markers among unaffected family members. We assessed the possible presence, prevalence, and inheritance pattern of subclinical intestinal inflammation in apparently healthy relatives of patients with Crohn's disease.

METHODS

A total of 49 patients with Crohn's disease, 16 spouses, and 151 (58%) of 260 available first-degree relatives underwent a test for intestinal inflammation (fecal calprotectin concentration). The mode of inheritance was assessed from 36 index patients (by variance component analysis) when more than 50% of relatives were studied.

RESULTS

Fecal calprotectin concentrations in patients with Crohn's disease (47 mg/L; confidence interval [CI], 27-95 mg/L) and relatives (11 mg/L; CI, 9-14 mg/L) differed significantly (P < 0.0001) from controls (4 mg/L; CI, 3-5 mg/L), whereas that of the spouses did not (4 mg/L; CI, 3-6 mg/L; P > 0.5). Fecal calprotectin concentration was increased in 49% of all relatives studied. The increased fecal calprotectin concentration among the relatives of the 36 index patients had an inheritance pattern that was most consistent with an additive inheritance pattern.

CONCLUSIONS

There is a high prevalence of subclinical intestinal inflammation in first-degree relatives of patients with Crohn's disease that conforms best to an additive inheritance pattern. The genetic basis for this abnormality may represent a risk factor for Crohn's disease.

Calprotectin levels in meconium

AIM

To evaluate the effect of gender, gestational age, birthweight, mode of delivery, 5'-Apgar score and maternal conditions on calprotectin concentrations in meconium.

METHODS

Calprotectin was measured in 131 neonates, in the first passed meconium.

RESULTS

Calprotectin levels (mean +/- SD) resulted in 145.2 +/- 78.5 mg kg(-1) meconium, significantly correlated with birthweight (r = -0.333; p < 0.001), gestational age (r = -0.206; p = 0.018) and 5'-Apgar score (r = -0.243, p = 0.035). The estimated regression model was: calprotectin levels (mg kg(-1)) = 269.58-41.54 weight (kg): r = 0.383, p < 0.001. No differences were found in relation to gender, mode of delivery and maternal conditions.

CONCLUSION

Calprotectin is already present in the first passed meconium, with higher levels in preterm and low birthweight neonates, as well as in neonates with some degree of perinatal asphyxia, as indicated by the negative correlation with 5'-Apgar score. These findings are probably secondary to both the immaturity of the intestinal mucosa and its hypoxic-ischaemic damage.

Faecal calprotectin levels in infants with infantile colic, healthy infants, children with inflammatory bowel disease, children with recurrent abdominal pain and healthy children

This study investigated faecal calprotectin concentration, a measure of intestinal inflammation, in infants and children with abdominal pain. Faecal calprotectin was measured by an enzyme-linked immunosorbent assay kit in spot stool samples in 76 infants with typical infantile colic, 7 infants with transient lactose intolerance and 27 healthy infants. All infants were 2-10 wk of age. In addition, 19 children with recurrent abdominal pain (RAP; mean age 11.5 y), 17 with inflammatory bowel disease (IBD; mean age 11.1 y; 10 had Crohn's disease and 7 ulcerative colitis) and 24 healthy children (mean age 5.3 y) were studied. In infants with infantile colic the mean faecal calprotectin concentration was not different from that in healthy infants (278 +/- 105 vs 277 +/- 109 mg kg(-1), p = 0.97) or in infants with transient lactose intolerance (300.3 +/- 124 mg kg(-1), p = 0.60). The calprotectin level was similar in boys and girls and fell significantly with age (p = 0.04). Children with IBD had faecal calprotectin levels (293 +/- 218 mg kg(-1)) much higher than healthy children (40 +/- 28 mg kg(-1), p < 0.0001) and children with RAP without identified organic disease (18 +/- 24 mg kg(-1), p < 0.0001).

CONCLUSION

Faecal calprotectin may differentiate between functional abdominal pain and IBD in school-aged children. In young infants high faecal calprotectin levels are normal.

Faecal calprotectin: a marker of inflammation throughout the intestinal tract

OBJECTIVE

To assess the potential of measuring the calcium-binding protein calprotectin in faeces as a method of screening for alimentary inflammation and neoplasia.

SETTING

Hospital day services unit for endoscopy and faecal analysis in the clinical biochemistry department.

PARTICIPANTS

Consented patients attending for routine endoscopy were requested to provide faeces. Seventeen of the initial 30 patients provided faeces before and 1 week after endoscopy. After this, 116 patients for planned endoscopy provided faeces before endoscopy. The group comprised 43 patients with upper-gastrointestinal lesions, seven patients with inflammatory bowel disease, seven patients with irritable bowel syndrome, 31 patients with colonic disorders, and 28 normal people. A final 18 patients with known inflammatory bowel disease (seven patients), gastric carcinoma (one patient), colorectal cancer (eight patients) and colorectal adenoma (two patients) had faeces analysed.

METHOD

Faeces were analysed by the Nycotest PhiCal enzyme-linked immunosorbent assay (ELISA) (Nycomed, Oslo, Norway), and the final 18 patients were analysed by the newer version marketed as Calprest.

RESULTS

No definite differences between pre- and post-endoscopy calprotectin were found, but it was considered preferable in the subsequent patients to analyse pre-endoscopy faeces. Upper-gastrointestinal disorders showed little difference in calprotectin levels, Barrett's oesophagus (median 6.8 mg/l), gastric ulcer (median 6.5 mg/l) or gastritis/duodenitis (median 5.2 mg/l), but these levels were all higher than the median calprotectin level of normal subjects (4.5 mg/l). The oesophageal and gastric carcinoma median was elevated significantly at 30 mg/l. Inflammatory bowel disease was also associated with marked elevation (Crohn's disease, 31.2 mg/l; ulcerative colitis, 116.2 mg/l). Colorectal polyps (median 3.7 mg/l) and adenoma (median 3.8 mg/l) showed no elevated levels in contrast to colorectal carcinoma (median 53.4 mg/l). The elevated calprotectin in inflammatory bowel disease and colorectal carcinoma combined gave a sensitivity of 81.8% and a specificity of 73.2%.

CONCLUSIONS

Calprotectin levels are elevated in inflammation and cancer but are not helpful in differentiating between these disorders. In our series, calprotectin was not elevated in colonic polyps or adenomata. Calprotectin could be helpful as a screening method in a general gastroenterology population for inflammatory bowel disease and those with carcinoma, as well as assessing and monitoring disease activity in inflammatory bowel disease.

Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease

BACKGROUND & AIMS

Differentiating symptoms of irritable bowel syndrome (IBS) from those of organic intestinal disease is a familiar problem for physicians. The aim of this study was to assess the sensitivity, specificity, and odds ratios (ORs) of fecal calprotectin, small intestinal permeability, Rome I criteria, and laboratory markers of inflammation (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], blood count) in distinguishing organic from nonorganic intestinal disease.

METHODS

A total of 602 new referrals to a gastroenterology clinic who had symptoms suggestive of IBS or organic intestinal disease were studied for these parameters. All patients underwent invasive imaging (barium/endoscopic examination) and other investigations as appropriate, with physicians blinded to the results of fecal calprotectin and intestinal permeability.

RESULTS

A total of 263 patients were diagnosed with organic disease and 339 with IBS. At 10 mg/L, the sensitivity and specificity of calprotectin for organic disease were 89% and 79%, respectively, and that of intestinal permeability for small intestinal disease were 63% and 87%, respectively. Sensitivity of positive Rome criteria for IBS was 85% with a specificity of 71%. An abnormal calprotectin test had an OR for disease of 27.8 (95% confidence interval [CI], 17.6-43.7; P < 0.0001) compared with ORs of 4.2 (95% CI, 2.9-6.1; P < 0.0001) and 3.2 (95% CI, 2.2-4.6; P < 0.0001) for elevated CRP and ESR values. An abnormal permeability test gave an OR of 8.9 (95% CI, 5.8-14.0; P < 0.0001) for small intestinal disease. The OR for IBS with positive Rome criteria was 13.3 (95% CI, 8.9-20.0).

CONCLUSIONS

Fecal calprotectin, intestinal permeability, and positive Rome I criteria provide a safe and noninvasive means of helping differentiate between patients with organic and nonorganic intestinal disease.

Faecal calprotectin: a marker of inflammation throughout the intestinal tract

Only a small proportion of patients with abdominal discomfort have organic disease, but a correct diagnosis can seldom be made by simple clinical examination. Additional diagnostic procedures must be employed, but these are expensive and demanding and carry a certain risk. Assessment of faecal concentrations of the neutrophil granulocyte-derived protein calprotectin can be used as a screening test--an 'ESR of the gut'--to select patients for further examination. The test can be performed on 1-2 g of random stool samples that can be sent to the laboratory by ordinary mail since the protein is remarkably stable in stools. The test has high sensitivities and specificities for gastrointestinal cancers and inflammatory bowel disease (IBD). Faecal calprotectin levels reflect the disease activity in IBD and can be used to monitor the response to treatment and detect relapses.

A study of the effects of restraint stress on colitis induced by dextran sulphate sodium in singly housed rats

The inflammatory bowel diseases (Crohn's disease and ulcerative colitis) are multifactorial diseases. Clinical reports indicate that emotional stress may contribute to the onset, progression and remission of these diseases. Using an experimental animal model of ulcerative colitis, the effect of stress on the development of and recovery from symptoms was studied prospectively. Singly housed rats received 4 percent dextran sulphate sodium orally until fecal blood was detected, indicating the presence of colonic erosions. Tap water was then administered until there were no signs of fecal blood. Two hours of restraint stress were administered daily over four successive days, either prior to or after the induction of colitis. Latencies in days to symptom development and recovery were compared to an unstressed group. Daily measures of fluid-intake, body-weight, and hemoglobulin in feces were made.

RESULTS

Rats exposed to restraint stress procedures prior to induction of colitis had shorter latencies to development of symptoms. There was no significant difference in latency to recovery. The amount of fluid-intake did not significantly differ between groups, nor did the groups differ in body-weight.

CONCLUSION

There is an effect of stress on the latency to develop colitis induced by dextran sulphate sodium. This preliminary study suggests that the impact of stress may be one factor underlying the emergence of ulcerative colitis.

Review article: faecal markers in the assessment of activity in inflammatory bowel disease

The fundamental pathological process behind ulcerative colitis and Crohn's disease is intestinal inflammation. As the precise cause of this is not yet completely understood, current treatment strategies are aimed at reducing or eliminating the inflammation. Endoscopic examination and histological analysis of biopsy specimens remain the 'gold standard' methods for detecting and quantifying bowel inflammation; however, these techniques are costly, invasive, and repeated examinations are unpopular with patients. Disease activity questionnaires and laboratory 'inflammatory markers', although widely used, show an unreliable correlation with endoscopy and histology. New markers need to be developed to detect and quantify bowel inflammation. These would be of use diagnostically and also an aid to pharmacological treatment.

(51)CrEDTA colonic permeability and therapy response in patients with ulcerative colitis

Orally administered (51)Cr-labelled ethylenediaminetetraacetic acid ((51)CrEDTA) has been used to evaluate intestinal permeability in inflammatory bowel disease, especially Crohn's disease. However, information about colonic permeability in ulcerative colitis (UC) is relatively scarce. The aim of this study was to investigate the urinary excretion of orally administered (51)CrEDTA, its relation to disease activity and its response to medical therapy in patients with UC. Forty-three patients with UC and 19 controls were examined. Disease activity was evaluated by endoscopy. In 19 patients with active UC, the (51)CrEDTA permeability test was repeated after medical therapy. (51)CrEDTA (95 microCi; 26 MBq) was given orally after an overnight fast and urine was collected over a 24 h period. The first urine samples were taken 5 h and the second 24 h after the oral administration of (51)CrEDTA. Urine samples were counted in a gamma counter. In controls, the median 5 h and 24 h excretions were 0.10% and 0.93%, respectively. Patients with UC showed significantly increased urine (51)CrEDTA excretion at both time intervals (5 h: 2.41%, P<0.0002; 24 h: 6.72%, P<0.0001). There was also a significant correlation between intestinal permeability and disease activity (5 h: r=0.45, P=0.0025; 24 h: r=0.51 P=0.0006). After medical therapy, (51)CrEDTA urinary excretion was significantly decreased (pre-treatment UC: 7.87%; post-treatment UC: 2.50%; P<0.0002). Briefly, the (51)CrEDTA test reflected colonic permeability in UC and might be useful as an indicator of disease severity. Moreover, this study suggested that, in patients with UC, medical therapy not only leads to the recovery of acute inflammation but also restores mucosal barrier integrity and function.

Non-invasive investigation of inflammatory bowel disease

The assessment of inflammatory activity in intestinal disease in man can be done using a variety of different techniques. These range from the use of non-invasive acute phase inflammatory markers measured in plasma such as C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) (both of which give an indirect assessment of disease activity) to the direct assessment of disease activity by intestinal biopsy performed during endoscopy in association with endoscopic scoring systems. Both radiology and endoscopy are conventional for the diagnosis of inflammatory bowel disease (IBD). However these techniques have severe limitations when it comes to assessing functional components of the disease such as activity and prognosis. Here we briefly review the value of two emerging intestinal function tests. Intestinal permeability, although ideally suited for diagnostic screening for small bowel Crohn’s disease, appears to give reliable predictive data for imminent relapse of small bowel Crohn’s disease and it can be used to assess responses to treatment. More significantly it is now clear that single stool assay of neutrophil specific proteins (calprotectin, lactoferrin) give the same quantitative data on intestinal inflammation as the 4-day faecal excretion of 111Indium labelled white cells. Faecal calprotectin is shown to be increased in over 95% of patients with IBD and correlates with clinical disease activity. It reliably differentiates between patients with IBD and irritable bowel syndrome. More importantly, at a given faecal calprotectin concentration in patients with quiescent IBD, the test has a specificity and sensitivity in excess of 85% in predicting clinical relapse of disease. This suggests that relapse of IBD is closely related to the degree of intestinal inflammation and suggests that targeted treatment at an asymptomatic stage of the disease may be indicated.

B2 microglobulin: is it a reliable marker of activity in inflammatory bowel disease?

OBJECTIVES

The aims of this study were to investigate a possible positive correlation between B2-microglobulin (B2-M) serum levels and the severity and activity of inflammatory bowel disease (IBD); and to examine whether B2-M levels reflect IBD extent.

METHODS

We examined B2-M serum levels in 87 ulcerative colitis (UC) patients, 74 with Crohn's disease (CD) and 68 control subjects, using an enzymatic method. The reliability of the measuring method was assessed by evaluating serum B2-M in 18 patients suffering from chronic renal failure (CRF). The severity and activity of IBD was estimated using the van Hees Activity Index and the True-love-Witts criteria for CD and UC patients respectively. Endoscopic evaluation for UC patients was done according to Baron's et al. classification; Riley's et al. criteria were used for histological evaluation.

RESULTS

B2-M serum levels were significantly increased in all CD patients except those in remission. After 6 months treatment a second blood sample taken from CD patients with initially elevated B2-M levels proved to be compatible with CD severity at that time. Such a positive correlation was not assessed in UC patients; therefore, a second blood sample was considered unnecessary. Furthermore, CD patients with pancolitis, ileal-caecal, or small intestinal disease had higher B2-M levels than those with left-sided, anal, or perianal disease.

CONCLUSIONS

B2-M serum levels could prove to be a useful marker in assessing not only the activity, severity, and extent of CD but the treatment efficacy as well.

Fecal calprotectin: validation as a noninvasive measure of bowel inflammation in childhood inflammatory bowel disease

BACKGROUND

Calprotectin is an abundant neutrophil protein, which is extremely stable in feces. This study aimed to validate fecal calprotectin as a marker of bowel inflammation against invasive measures in children with inflammatory bowel disease (IBD), including colitis and small bowel Crohn disease.

METHODS

Fecal calprotectin was measured using a simple enzyme-linked immunosorbent assay in 36 spot stool samples from 22 children before colonoscopy and from 14 children before technetium-99 (99Tc) scanning. Using standard scoring systems, the severity of inflammation was assessed macroscopically and histologically at six standard sites in those who underwent colonoscopy and also at six standard sites in those who underwent 99Tc scanning. The subscores from each site were summated to give combined severity and extent scores for macroscopic and for histologic inflammation in the group undergoing colonoscopy and total inflammation in the group undergoing 99Tc scanning.

RESULTS

In the 22 children who underwent colonoscopy, median fecal calprotectin was 4.9 mg/L (0.1-272.5 mg/L) (range). Disease groups included six normal cases, nine ulcerative colitis cases, two isolated Crohn colitis cases, two indeterminate colitis cases, and three allergic colitis cases. Fecal calprotectin correlated closely with colonic macroscopic inflammation (r = 0.75, P < 0.001) and histologic inflammation (r = 0.85, P < 0.001). Of the 14 children undergoing 99Tc scanning, 10 had Crohn disease, 3 had ulcerative colitis, and 1 had allergic colitis. Median fecal calprotectin was 9.1 mg/L (0.3-141.7 mg/L), and this correlated closely with the 99Tc scanning score (r = 0.80, P = 0.001).

CONCLUSION

Fecal calprotectin correlates closely with the best invasive measures of colonic and small bowel inflammation in childhood inflammatory bowel disease. As a sensitive objective measure of bowel inflammation that is risk-free and noninvasive, fecal calprotectin lends itself particularly to the monitoring of and assessment of therapeutic interventions in children with inflammatory bowel disease.

Radiation-induced granulocyte transmigration predicts development of delayed structural changes in rat intestine

We examined whether early radiation-induced granulocyte transmigration (assessed by the fecal transferrin excretion ELISA assay) predicts subsequent development of (consequential) chronic radiation enteropathy. After accounting for the effect of radiation dose, transferrin excretion remained an independent predictor of overall tissue injury, intestinal fibrosis, and mucosal ulcers, but not TGF-beta immunoreactivity.

Fecal calprotectin as a measure of disease activity in childhood inflammatory bowel disease

BACKGROUND

Calprotectin is an abundant neutrophil protein that is extremely stable in feces. The aim of this study was to assess the effectiveness of fecal calprotectin as a noninvasive measure of disease activity in childhood inflammatory bowel disease (IBD) by comparison to a modified Lloyd-Still and Green score and laboratory inflammatory indices.

METHODS

Spot fecal samples from 37 children with IBD and 31 control children were sent by ordinary mail to the laboratory. Fecal calprotectin concentration was measured by an in-house enzyme linked immunosorbent assay (ELISA). A modified Lloyd-Still & Green score (mLSS) was calculated for each child with IBD within 10 days of obtaining the fecal sample.

RESULTS

Compared with control values (median, range) (2.1, 0.5-6.3 mg/L), fecal calprotectin was increased in 16 children with ulcerative colitis, (11.5, 0.6-272.5 mg/L, P < 0.001) and in 21 children with Crohn disease, (14.0, 0.7-59.7 mg/L, P < 0.001). Twelve "moderately affected" children (mLSS of 35-65) had higher fecal calprotectin concentrations (22.2, 2.7-141.7 mg/L) than 25 "mildly affected" children (mLSS > 65), (10.3, 0.6-272.5 mg/L, P = 0.002). For the total IBD group, fecal calprotectin concentration correlated negatively with the mLSS (r = -0.61, P < 0.001). It also correlated negatively with serum albumin concentration (r = -0.49, P = 0.002) and positively with erythrocyte sedimentation rate (r = 0.40, P = 0.01).

CONCLUSIONS

Fecal calprotectin seems to reflect bowel inflammation in children with IBD. As a simple, safe, noninvasive test, it has the potential to reduce the number of invasive investigations performed in these children.

Fecal calprotectin levels predict colorectal inflammation among patients with chronic diarrhea referred for colonoscopy

OBJECTIVE

Chronic diarrhea is a relatively common condition with multiple diverse etiologies. Stool testing may serve as a diagnostic aid to discriminate the presence or absence of organic pathology, such as colorectal inflammation. Calprotectin (a leukocyte-derived protein) and hemoglobin can be measured quantitatively from stool and represent candidate inflammation biomarkers. The aim of this study was to assess and compare the screening performance of fecal calprotectin and fecal hemoglobin among colonoscopy referral patients with chronic diarrhea of unknown origin or chronic colitis of unknown activity.

METHODS

All subjects were identified prospectively and each submitted a single stool sample before purgation. Fecal calprotectin (PhiCal; Nycomed Pharma, Oslo, Norway) and fecal hemoglobin (HemoQuant; Mayo Medical Laboratories, Rochester, MN) assays were performed in separate laboratories by masked technicians. Colonoscopic and histological findings served as criterion standards for establishing the presence or absence of colorectal inflammation.

RESULTS

Among 110 subjects who provided complete fecal assay data, 29 (26%) had and 81 (74%) did not have colorectal inflammation. Increased fecal calprotectin levels were significantly (p = 0.0001) associated with the presence of colorectal inflammation, whereas fecal hemoglobin levels were not (p = 0.61). Direct comparison of the fecal assays revealed that calprotectin was a more sensitive biomarker for colorectal inflammation at all specificity levels (p = 0.0001).

CONCLUSIONS

In this study of colonoscopy referral patients, colorectal inflammation was reflected by fecal calprotectin but not by fecal hemoglobin levels. Assay of fecal calprotectin holds promise as a triage tool to identify inflammatory causes of chronic diarrhea.

Surrogate markers of intestinal inflammation are predictive of relapse in patients with inflammatory bowel disease

BACKGROUND & AIMS

Prediction of relapse of inflammatory bowel disease has important implications for therapeutic strategies. We assessed whether measurement of intestinal permeability and inflammation could predict relapse of inflammatory bowel disease (IBD).

METHODS

Forty-three patients with Crohn's disease (CD) and 37 with ulcerative colitis (UC) in clinical remission provided a stool sample to be assayed for calprotectin (a neutrophil-specific marker), and patients with CD additionally underwent a small intestinal permeability test. Relapse was defined using clinical disease activity indices.

RESULTS

Twenty-five (58%) patients with CD and 19 (51%) with UC had a relapse over the 12-month period. Median calprotectin levels in the relapse groups (122 mg/L for CD, 123 mg/L for UC; normal <10 mg/L) differed significantly (P<0.0001) from those of the nonrelapse groups (41.5 mg/L for CD, 29.0 mg/L for UC). At 50 mg/L, the sensitivity and specificity of calprotectin for predicting relapse in all patients with IBD were 90% and 83%, respectively. Permeability in the CD patients who relapsed (median, 0.075; normal <0.04) differed significantly (P = 0. 004) from that in the nonrelapse group (median, 0.038). At the level of 0.05, the sensitivity and specificity of permeability in predicting relapse were 84% and 61%, respectively.

CONCLUSIONS

Fecal calprotectin predicts clinical relapse of disease activity in patients with CD and UC, whereas small intestinal permeability is a useful predictor of relapse in patients with small intestinal CD.

Improved assay for fecal calprotectin

Fecal calprotectin is a marker of inflammatory and neoplastic disease in the lower gastrointestinal tract. A new fecal sample preparation procedure for the measurement of calprotectin has been developed, with higher calprotectin yield and lower contamination risk. Changes in the new method compared to the original [Roseth AG, Fagerhol MK, Aadland E, Schonsby H. Assessment of the neutrophil dominating protein calprotectin in feces. A methodologic study. Scand J Gastroenterol 1992;27(9):793-798] are smaller sample size, higher dilution of the sample, presence of dissociating agents in the extraction solution and procedure performed in closed disposable tubes. The extraction yield was 78% (41-100%) of total calprotectin, giving an overall five-fold increase compared to the original method. Samples with high calprotectin values were increased to a slightly higher degree, than low calprotectin samples, thus improving the separation between high and low calprotectin levels. Median calprotectin level in healthy subjects was 26 microg/g. Pathological samples with pancolitis showed levels up to 30000 microg/g. The mean C.V. (coefficient of variation) in blended feces was lower than that of unblended, suggesting uneven distribution of calprotectin. However, no significant difference between spot measurements was found when five samples from each of 47 stools were measured. Thus measurements of calprotectin in fecal samples were accurate and reproducible. No interference with foods or relevant oral pharmaceuticals or nutraceuticals was found.

Assessment of ileal pouch inflammation by single-stool calprotectin assay

PURPOSE

Assessment of inflammation within the ileal pouch to establish a diagnosis of "pouchitis" requires both pouch endoscopy and biopsy because there can be a poor correlation between macroscopic and histologic assessments of inflammation. A simplified diagnostic test would be of clinical advantage. Calprotectin is a stable myelomonocytic protein, measurable in feces. It quantitatively relates to inflammation within the gastrointestinal tract. This study was designed to compare single and 24-hour stool measurements of calprotectin in patients with and without evidence of ileal pouch inflammation with endoscopic, histologic, and immunohistochemical indices.

METHODS

Twenty-four-hour stool collections were made in ileal pouch patients, 9 with and 15 without (7 with ulcerative colitis and 8 with familial polyposis coli) evidence of pouch inflammation. First-morning stool concentration and total 24-hour calprotectin were quantified by use of a single step enzyme-linked immunosorbent assay. Biopsies from the reservoir were taken for conventional histology and scoring of intraepithelial neutrophil infiltrate. Cells positive for CD3, CD45RO, CD14, and CD15 within the lamina propria were quantified by use of immunohistochemistry.

RESULTS

The mean first-morning stool calprotectin concentration correlated with the 24-hour level (r = 0.91; P = <0.0001). The median single-stool calprotectin concentrations were 39 mg/l, 4 mg/l, and 8.5 mg/l (normal range, 0.2-10 mg/l) in patients with inflamed, noninflamed ulcerative colitis, and familial adenomatous polyposis, respectively. All nine patients with endoscopic and histologic evidence of pouch inflammation had raised stool calprotectin. Two of 15 patients without evidence of pouch inflammation had abnormal stool calprotectin. Single-stool calprotectin concentration correlated with the percentage of mature granulocytes (CD15; r = 0.46; P = 0.04) and activated macrophages (CD14; r = 0.65; P = 0.006), but not memory T cells (CD45RO; r = -0.05; P = 0.4) within the lamina propria.

CONCLUSION

Single first-morning stool calprotectin levels provide a quantitative measure of pouch inflammation, which may be helpful in the diagnosis and assessment of pouchitis.