Utility of faecal calprotectin in inflammatory bowel disease (IBD): what cut-offs should we apply?

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.

A double-blind, placebo-controlled study to assess the effect of a probiotic mixture on symptoms and inflammatory markers in women with diarrhea-predominant IBS

BACKGROUND

Micro-inflammation is considered an element in the pathogenesis of irritable bowel syndrome (IBS). High-sensitivity C reactive protein (hs-CRP) was previously shown to be higher in IBS compared to healthy controls, albeit within the normal range. Since probiotics may suppress micro-inflammation in the gut, we tested if they reduce symptoms and inflammatory markers (hs-CRP and fecal calprotectin (FC) in diarrhea-predominant IBS (IBS-D). The aim of this study was to assess the clinical and laboratory effects of BIO-25, a multispecies probiotic, in women with IBS-D.

METHODS

A double-blind, placebo-controlled study. Following a 2-week run-in, eligible women were assigned at random to a probiotic capsule or an indistinguishable placebo, twice daily for 8 weeks. IBS symptoms and stool consistency were rated daily by Visual Analogue Scales (VAS) and the Bristol Stool Scale (BSS). High-sensitivity C reactive protein was tested at baseline, 4 and 8 weeks. FC was tested at baseline and 8 weeks.

KEY RESULTS

One hundred and seventy-two IBS-D patients were recruited and 107 eligible patients were allocated to the intervention (n=54) or placebo (n=53) group. All symptoms improved in both groups with no significant difference between them in symptom improvement, hs-CRP or FC levels.

CONCLUSIONS & INFERENCES

An 8-week treatment with BIO-25 improved symptoms in women with IBS-D, but was not superior to placebo. This rigorously designed and executed study supports the findings of other studies that did not demonstrate superiority of probiotics over placebo in IBS. High quality clinical studies are necessary to examine the efficacy of other specific probiotics in IBS-D patients since data are still conflicting.

Clinical implications of assay specific differences in f-calprotectin when monitoring inflammatory bowel disease activity over time

OBJECTIVE

With several faecal calprotectin (FC) assays on the market, it has been difficult to define a uniform threshold for discriminating between remission and active disease in patients with inflammatory bowel disease (IBD). We aimed to compare the results of different FC-assays in IBD patients, followed over time.

MATERIAL AND METHODS

IBD patients provided faecal samples and reported clinical activity every third month prospectively over a two year period. FC was measured with two ELISA - (Bühlmann and Immunodiagnostik) and one automated fluoroimmunoassay (Phadia).

RESULTS

In total, 13 patients provided 91 faecal samples. The median (IQR) concentration of FC was higher at active disease than at remission for all assays: Bühlmann 845 (1061-226) μg/g versus 62 (224-39) μg/g, Phadia 369 (975-122) μg/g versus 11 (52-11) μg/g, and Immundiagnostik 135 (302-69) μg/g versus 8 (56-4) μg/g. The Bühlmann assay produced the largest absolute difference but the corresponding relative difference seemed to be more pronounced when analysed by the Phadia - (ratio of means 8.5; 95% CI 3.3-21.9) or the Immundiagnostik assay (ratio of means 7.4; 95% CI 3.1-17.6) than by the Bühlmann assay (ratio of means 5.3; 95% CI 2.7-10.6). Consequently, the specificity for discriminating active disease from remission varied between assays (34-75%) when the cut-off 50 μg/g was used, whereas the differences in sensitivity were less pronounced.

CONCLUSIONS

Cross-comparisons revealed overall poor agreement between the assays as well as differences in the dynamics of FC. These findings suggest that standardisation of the method is needed to implement FC as a disease monitoring tool at large-scale.

Concurrent immunomodulator therapy is associated with higher adalimumab trough levels during scheduled maintenance therapy

INTRODUCTION

Combination therapy with infliximab and immunomodulators is superior to monotherapy, resulting in better outcomes and higher trough levels of infliximab. The role of concurrent immunomodulatory therapy on adalimumab trough levels has not been adequately investigated. We evaluated the impact of concomitant immunomodulation on adalimumab trough levels in patients on scheduled maintenance therapy.

METHOD

We conducted a prospective observational, cross-sectional study of all inflammatory bowel disease patients on maintenance therapy who had adalimumab trough levels measured between January 2013 and January 2016. Drug level and anti-drug antibody measurements were performed on sera using a solid phase assay. Pairwise comparison of means was used to compare trough levels in patients with and without concomitant immune modulator therapy.

RESULTS

In total, 79 patients were included. Twenty-three patients (29.1%) were on weekly dosing whereas 56 (70.9%) were on alternate weeks. Median adalimumab trough levels were comparable in patients with and without clinical remission (6.8 μg/ml (IQR 5.6-8.1) versus 6.7 μg/ml (IQR 3.9-8.1), respectively. Patients with an elevated faecal calprotectin >250 μg/g had lower adalimumab trough levels (median 6.7, IQR 3.9-8) compared to patients with faecal calprotectin <250 μg/g (median 7.7, IQR 6.1-8.1) though this did not achieve statistical significance (p = .062). Median adalimumab trough levels among patients on concurrent immunomodulators was 7.2 μg/ml (IQR 5.7-8.1) compared to those not on concurrent immunomodulator, 6.1 μg/ml (IQR 2.7-7.7, p = .0297).

CONCLUSION

Adalimumab trough levels were significantly higher in patients on concurrent immunomodulators during maintenance therapy. There was a trend towards a lower adalimumab trough level in patients with elevated calprotectin.

Diagnostic accuracy of faecal biomarkers in detecting colorectal cancer and adenoma in symptomatic patients

BACKGROUND

The diagnosis of colorectal cancer (CRC) can be difficult as symptoms are variable with poor specificity. Thus, there is a quest for simple, non-invasive testing that can help streamline those with significant colonic pathology.

AIM

To assess using faecal immunochemical test for haemoglobin (FIT) or faecal calprotectin (FCP) to detect CRC and adenoma in symptomatic patients referred from primary care.

METHODS

A total of 799 referred for urgent lower gastrointestinal investigations were prospectively recruited. Of these, 430 completed colonic investigations and returned stool samples, and were included in the final statistical analysis. Faecal immunochemical test for haemoglobin was performed on HM-JACKarc analyser (Kyowa Medex, Tokyo, Japan), and FCP by the EliA Calprotectin immunoassay (Thermo Fisher Scientific, Waltham, United States).

RESULTS

The negative predictive value (NPV) using FIT alone or both markers (FIT and FCP) in combination was similar at 99% for CRC, with a sensitivity and specificity of 84% and 93%, respectively. FIT measurements were significantly higher in left-sided colonic lesions compared with the right side; 713 vs. 94; P = 0.0203). For adenoma, the NPV using FIT alone, or both markers (FIT and FCP) in combination, was similar at 94% with a sensitivity and specificity of 69% and 56%, respectively.

CONCLUSIONS

Undetectable faecal immunochemical test for haemoglobin is sufficiently sensitive to exclude colorectal cancer, with higher values in left-sided lesions. FCP in combination does not appear to provide additional diagnostic information. Further studies to determine the health economic benefits of implementing faecal immunochemical test for haemoglobin in primary care are required.

Comparison of Fecal Calprotectin Methods for Predicting Relapse of Pediatric Inflammatory Bowel Disease

Background. Pediatric inflammatory bowel disease (IBD) is on the rise worldwide. Endoscopies are necessary for IBD assessment but are invasive, expensive, and inconvenient. Recently, fecal calprotectin (FCal) was proposed as a noninvasive and specific marker of gut inflammation. We evaluated the analytical performance of three FCal assays and their clinical performance in predicting relapse in pediatric IBD. Methods. This study used 40 pediatric IBD and 40 random non-IBD patients' fecal samples. Two automated ELISAs (Bühlmann and PhiCal® Calprotectin-EIA) and an EliA (Phadia 250 EliA-Calprotectin) were used to evaluate the analytical performance. The clinical performance was assessed by PhiCal Calprotectin-EIA, EliA-Calprotectin, and Bühlmann immunochromatographic point-of-care test (POCT). Results. All assays displayed acceptable analytical performance below and above the medical decision cut-off [imprecision (CV < 10% intra-assay; <15% interassay); linearity (overall mean % deviation < 16.5%)]. The agreement with PhiCal Calprotectin-EIA was 100% and 78.6% for Bühlmann (95% CI, 87.5-100; Kappa: 1) and EliA-Calprotectin (95% CI, 60.5-89.8; Kappa: 0.32), respectively, and 63.6% between Bühlmann and EliA-Calprotectin (95% CI, 46.6-77.8; Kappa: 0.16). All assays evaluated had similar clinical performance [AUC: 0.84 (EliA-Calprotectin); 0.83 (POCT and PhiCal Calprotectin-EIA)]. Conclusion. FCal levels determined using the same method and assay together with clinical history would be a noninvasive and useful tool in monitoring pediatric IBD.

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.

Fecal calprotectin for diagnosis of inflammatory bowel disease: A meta-analysis

AIM

To evaluate the value of the fecal calprotectin in the diagnosis of inflammatory bowel disease (IBD) patients systematically.

METHODS

PubMed, EMBASE, CNKI, and Wanfang digital journals database were searched for the studies which evaluated the value of the fecal calprotectin in the diagnosis of IBD patients. Meta-Disc 1.40 was used to calculate the pooled sensitivity, specificity and 95% confidence intervals (95%CI). The summary receiver operating characteristic curve (SROC), the area under the curve (AUC), and Q* were also calculated.

RESULTS

A total of 13 studies involving 721 IBD patients and 664 controls were finally included in this meta-analysis. The pooled sensitivity and specificity were 0.86 (95%CI: 0.84-0.88) and 0.76 (95%CI: 0.74-0.79), respectively. The AUC was 0.9169, and the Q* was 0.8498.

CONCLUSION

Fecal calprotectin is a good noninvasive marker with high sensitivity and specificity in the diagnosis of IBD patients.

Validation of a Simple 0 to 10 Numerical Score (IBD-10) of Patient-reported Inflammatory Bowel Disease Activity for Routine Clinical Use

BACKGROUND

Various physician- and patient-reported instruments exist for quantification of disease activity in inflammatory bowel diseases (IBD) but none are widely used in routine clinical practice. A simple patient-reported outcome measure might help inform clinical decision making. We evaluated a patient-reported 0 to 10 score of IBD activity (IBD-10) by correlation with conventional multicomponent activity indices.

METHODS

A single-center prospective cross-sectional study was conducted in ambulant patients with IBD. Patients were asked to verbally rate the control of Crohn's disease (CD) or ulcerative colitis (UC) on a numerical scale from 0 to 10, with 10 indicating perfect control. Disease activity was assessed using Harvey-Bradshaw index for CD and simple clinical colitis activity index for UC.

RESULTS

A total of 405 patients were included, of whom 209 (52%) had CD and 196 (48%) had UC. The median age was 41 (interquartile range, 27-55) years. IBD-10 correlated well with Harvey-Bradshaw Index (rs = -0.69, P < 0.001) and simple clinical colitis activity index (rs = -0.79, P < 0.001). An IBD-10 score of ≥7 predicted remission (defined by Harvey-Bradshaw index/simple clinical colitis activity index) with 90% sensitivity (95% confidence interval [CI], 86-94) and 75% specificity (95% CI, 67-82). The discriminatory ability of IBD-10 for remission was better for UC (area under the receiver operating characteristic curve, 0.93; 95% CI, 0.89-0.97) than for CD (area under the receiver operating characteristic curve, 0.86; 95% CI, 0.81-0.91; P = 0.035). An IBD-10 score of <7 correlated with treatment escalation.

CONCLUSIONS

The IBD-10 score correlates well with more complex clinical activity indices. Correlation was less strong for CD than for UC, possibly reflecting a weaker link in CD between stool frequency and the patient perspective of disease activity. The IBD-10 score could readily be used in routine clinical practice.

Association Between Fecal Calprotectin Levels and Small-bowel Inflammation Score in Capsule Endoscopy: A Multicenter Retrospective Study

BACKGROUND

Accurate inflammation reporting in capsule endoscopy (CE) is important for diagnosis and monitoring of treatment of inflammatory bowel disease (IBD). Fecal calprotectin (FC) is a highly specific biomarker of gut inflammation. Lewis score (LS) was developed to standardize quantification of inflammation in small-bowel (SB) CE images.

GOALS

Multicenter retrospective study aiming to investigate correlation between LS and FC in a large group of patients undergoing CE for suspected or known small-bowel IBD, and to develop a model for prediction of CE results (LS) based on FC levels.

STUDY

Five academic centers and a district general hospital offering CE in UK, Finland, Sweden, Canada, and Israel. In total, 333 patients were recruited. They had small-bowel CE and FC done within 3 months.

RESULTS

Overall, correlation between FC and LS was weak (r s: 0.232, P < 0.001). When two clinically significant FC thresholds (100 and 250 μg/g) were examined, the r s between FC and LS was 0.247 (weak) and 0.337 (moderate), respectively (P = 0.307). For clinically significant (LS ≥ 135) or negative (LS < 135) for SB inflammation, ROC curves gave an optimum cutoff point of FC 76 μg/g with sensitivity 0.59 and specificity 0.41.

LIMITATIONS

Retrospective design.

CONCLUSIONS

LS appears to show low correlation with FC as well as other serology markers of inflammation. FC does not appear to be a reliable biomarker for significant small-bowel inflammation. Nevertheless, FC level ≥ 76 μg/g may be associated with appreciable visual inflammation on small-bowel CE in patients with negative prior diagnostic workup.

Clinical outcomes at 12 months and risk of inflammatory bowel disease in patients with an intermediate raised fecal calprotectin: a 'real-world' view

OBJECTIVES

A recent systematic review confirmed the usefulness of fecal calprotectin (FC) in distinguishing organic (inflammatory bowel disease (IBD)) from non-organic gastrointestinal disease (irritable bowel syndrome (IBS)). FC levels <50 μg/g have a negative predictive value >92% to exclude organic gastrointestinal (GI) disease. Levels >250 μg/g correlate with endoscopic IBD disease activity; sensitivity 90%. We aimed to determine clinical outcomes in intermediate raised FC results (50-250 μg/g).

SETTING

Primary care general practices in Coventry and Warwickshire, and 3 secondary care hospitals.

PARTICIPANTS

443 FC results in adults (>16 years old) were reviewed from July 2012 to October 2013. Clinical data was collected from hospital databases and general practitioners. Long-term clinical data was available in 41 patients (out of 48).

PRIMARY AND SECONDARY OUTCOME MEASURES

The number of new diagnoses of IBD, IBS and other diagnoses for the intermediate group. The number referred and discharged from secondary care.

RESULTS

A new IBD diagnosis was made in 19% (n=8) of intermediate results (1% of normal and 38% of raised results). 5% (n=2) of intermediate results had known IBD in remission. A new IBS diagnosis was made in 27% (n=11) of intermediate results, while 34% (n=14) remained undiagnosed, although 8 of these were not referred to secondary care.

CONCLUSIONS

FC testing remains useful in aiding diagnosis of organic GI conditions. However, unlike negative and strongly positive FC results, intermediate FC results lead to a mixture of diagnoses. The OR of a new diagnosis of IBD for an intermediate result compared to normal FC result was 26.6, while an intermediate FC result gave an OR of 0.54 for a new IBS diagnosis compared to normal FC. For intermediate FC results, 1 in 3 patients remained in secondary care after 12 months with an OR of 3.6 compared to a normal FC result.

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.

Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye?

Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.

Elevated levels of faecal calprotectin in primary Sjögren's syndrome is common and associated with concomitant organic gastrointestinal disease

Background

Primary Sjögren’s syndrome (pSS) is a systemic rheumatic disease in which gastrointestinal (GI) symptoms are common. Faecal calprotectin (FC) is a non-invasive biomarker that has been suggested to discriminate organic intestinal disease from functional disorders. The purpose of this study was to explore the usefulness of FC testing in patients with pSS.

Methods

In total, 56 consecutive patients with pSS and 29 healthy control subjects were included in this cross-sectional study. FC was measured with a commercially available enzyme-linked immunosorbent assay kit. GI symptoms were evaluated with the Rome III questionnaire and the Visual Analogue Scale for Irritable Bowel Syndrome. In patients with pSS, disease activity was estimated using the European League Against Rheumatism (EULAR) Sjögren’s Syndrome Disease Activity Index (ESSDAI), and patient-reported outcomes were evaluated with the EULAR Sjögren’s Syndrome Patient-Reported Index.

Results

Patients with pSS had higher levels of FC than healthy control subjects (median 54 μg/g, interquartile range [IQR 20–128]; vs. 20 μg/g [20–43]; p = 0.002). Concomitant organic GI disease was found in 14 patients with pSS and included inflammatory bowel disease (n = 3), colonic adenoma (n = 2) and GI lymphoma (n = 1). Patients with organic GI disease had higher FC levels than the other patients with pSS (median 274 μg/g [IQR 61–363] vs. median 34 μg/g [IQR 20–76]; p < 0.001). Although patients with pSS reported abdominal discomfort more frequently than healthy control subjects did, such symptoms were not associated with organic GI disease or elevated FC levels. FC correlated moderately with ESSDAI. Excluding patients with organic GI disease, we did not identify any significant association between ESSDAI and FC levels.

Conclusions

GI symptoms are frequent in pSS. Contrary to patient-reported outcomes, elevated FC levels in pSS indicate possible organic GI disease that warrants further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0907-8) contains supplementary material, which is available to authorized users.

Small Intestinal Bacterial Overgrowth Syndrome Prevalence in Romanian Patients with Inflammatory Bowel Disease

BACKGROUND

small intestinal bacterial overgrowth (SIBO) is an entity commonly associated with digestive disease. Recently, its association with inflammatory bowel diseases (IBD) made the object of an increasing number of investigations. Sometimes symptoms of excessive bacterial populations may overlap or mimic flares of inflammatory disease.

METHOD

patients with IBD (CD - Crohn disease and UC - ulcerative colitis) in remission underwent screening for the presence of SIBO using the hydrogen breath test.

RESULTS

of the 75 patients tested, the breath test was positive for SIBO in 25.3% (30.77% of patients with CD and 19.4% of patients with UC). The risk factors associated with the presence of this syndrome were identified as: pancolonic impairment in UC, perianal and ileo-colonic involvement in CD, postoperative absence of the ileocecal valve. Patients in remission with bacterial overgrowth tend to present more frequently: a higher daily average of stools, a lower BMI (body mass index) and much more frequent complaints of persistent flatulence.

CONCLUSIONS

patients with Crohn's disease suffer from small intestinal bacterial overgrowth syndrome more frequently than those with ulcerative colitis. The hydrogen breath test may be used, along with other laboratory methods, to distinguish between an inflammatory bowel disease and an overlap of small intestinal bacterial overgrowth.

Avoid Endoscopy in Children With Suspected Inflammatory Bowel Disease Who Have Normal Calprotectin Levels

In children with suspected inflammatory bowel disease, adding calprotectin stool testing to the screening strategy has been recommended to distinguish organic from nonorganic disease. In this cohort study with historical controls, we could not confirm that screening with stool calprotectin improves the diagnostic yield (ratio inflammatory bowel disease-positive endoscopies and total number of endoscopies); however, in patients with normal fecal calprotectin levels (<50 μg/g) endoscopic and histological abnormalities were not seen. We propose to refrain from endoscopy when stool calprotectin levels are normal.

Usefulness of Adjunctive Fecal Calprotectin and Serum Procalcitonin in Individuals Positive for Clostridium difficile Toxin Gene by PCR Assay

In 54/64 subjects with nosocomial diarrhea, fecal calprotectin levels correlated with the results of stool samples tested for Clostridium difficile toxin gene by PCR. Fecal calprotectin levels can be used as an adjunctive measure to PCR to support the diagnosis of C. difficile infection.

Fecal calprotectin for diagnosis of digestive system diseases

Calprotectin is a 36 kDa calcium- and zinc-binding protein that belongs to the S100 family. Calprotectin shows an excellent stability in feces and appears to be superior to conventional fecal markers. Fecal calprotectin concentrations closely correlate with the fecal excretion of in-labelled leukocytes. In addition, fecal calprotectin has an overall high specificity. Therefore, it could be a useful marker for diagnosis of intestinal diseases. In this review we summarize the structure, physical and chemical characteristics of fecal calprotectin and analyze the relationship between calprotectin and intestinal diseases.

Diagnosis of Irritable Bowel Syndrome: Role of Potential Biomarkers

Irritable bowel syndrome is a disorder diagnosed on symptom-based criteria without inclusion of any objective parameter measurable by known diagnostic methods. Heterogeneity of the disorder and overlapping with more serious organic diseases increase uncertainty for the physician's work and increase the cost of confirming the diagnosis. This paper is an attempt to summarize the efforts to find adequate biomarkers for irritable bowel syndrome, which should shorten the time to diagnosis and reduce the cost. Most of the reviewed papers were observational studies from secondary care institutions. Since publication of the Rome III criteria in 2006, most recent studies use these for the recruitment of IBS patients. This is a positive step forward as future studies should use the same criteria, facilitating comparison of their results. Among the studied biomarkers, most evidence is provided for fecal calprotectin. Cutoff values for fecal calprotectin have still to be investigated prior to inclusion in the irritable bowel syndrome diagnostic algorithm.