Fecal S100A12: a novel noninvasive marker in children with Crohn's disease

Inflammatory bowel disease therapies and gut function in a colitis mouse model

BACKGROUND

Exclusive enteral nutrition (EEN) is a well-established approach to the management of Crohn's disease. Aim. To determine effects of EEN upon inflammation and gut barrier function in a colitis mouse model.

METHODS

Interleukin-10-deficient mice (IL-10(-/-)) were inoculated with Helicobacter trogontum and then treated with EEN, metronidazole, hydrocortisone, or EEN and metronidazole combination. Blood and tissue were collected at 2 and 4 weeks with histology, mucosal integrity, tight junction integrity, inflammation, and H. trogontum load evaluated.

RESULTS

H. trogontum induced colitis in IL-10(-/-) mice with histological changes in the cecum and colon. Elevated mucosal IL-8 mRNA in infected mice was associated with intestinal barrier dysfunction indicated by decreased transepithelial electrical resistance and mRNA of tight junction proteins and increased short-circuit current, myosin light chain kinase mRNA, paracellular permeability, and tumor necrosis factor- α and myeloperoxidase plasma levels (P < 0.01 for all comparisons). EEN and metronidazole, but not hydrocortisone, treatments restored barrier function, maintained gut barrier integrity, and reversed inflammatory changes along with reduction of H. trogontum load (versus infected controls P < 0.05).

CONCLUSION

H. trogontum infection in IL-10(-/-) mice induced typhlocolitis with intestinal barrier dysfunction. EEN and metronidazole, but not hydrocortisone, modulate barrier dysfunction and reversal of inflammatory changes.

Proteomics and metabolomics in inflammatory bowel disease

Genome-wide studies in inflammatory bowel disease (IBD) have allowed us to understand Crohn's disease and ulcerative colitis as forms of related autoinflammatory disorders that arise from a multitude of pathogenic origins. Proteomics and metabolomics are the offspring of genomics that possess unprecedented possibilities to characterize unknown pathogenic pathways. It has been about a decade since proteomics was first applied to IBD, and 5 years for metabolomics. These techniques have yielded novel and potentially important findings, but turning these results into beneficial patient outcomes remains challenging. This review recounts the history and context of clinical IBD developments before and after proteomics and metabolomics IBD in this field, discusses the challenges in consolidating high complexity data with physiological understanding, and provides an outlook on the emerging principles that will help interface the bioanalytical laboratory with IBD prognosis.

Improving relapse prediction in inflammatory bowel disease by neutrophil-derived S100A12

BACKGROUND

Prediction of inflammatory bowel disease relapse has important implications for therapeutic strategies. Fecal S100A12 has been reported as a novel marker of intestinal inflammation. The objective was to investigate the utility of S100A12 as a marker for the confirmation of stable remission and prediction of relapses.

METHODS

We consecutively included 147 adults and 34 children with Crohn's disease (n = 61) or ulcerative colitis (n = 120). Over a 3-year period, we collected 686 stool samples and 861 serum samples during regular follow-up visits. S100A12 and calprotectin levels were measured by an enzyme-linked immunoassay.

RESULTS

Fecal S100A12 correlated with S100A12 serum levels, other laboratory markers, as well as disease activity, location, and behavior. Fecal S100A12 levels in the relapse group differed significantly from those of the nonrelapse group. A baseline fecal S100A12 level of >0.5 mg/kg was significantly associated with disease relapse within 18 months. Time course analysis of fecal S100A12 before and after relapse showed a clear increase of S100A12 concentrations up to 6 months before clinical relapse. At 0.43 mg/kg, the sensitivity and specificity of S100A12 for predicting relapse already 8 to 12 weeks earlier were 70% and 83%, respectively.

CONCLUSIONS

Regular measurements of fecal S100A12 levels reliably detect inflammatory bowel disease relapse at an early stage, which makes the test a promising noninvasive tool for monitoring and optimizing therapy, and may reduce the need for invasive investigations during disease follow-up.

S100A12: a noninvasive marker of inflammation in inflammatory bowel disease

Inflammatory bowel diseases are incurable conditions that feature gut inflammation. Standard markers have inadequate sensitivity and specificity. S100A12 is a new fecal marker that has promise as a non-invasive indicator of gut inflammation. This article reviews recent studies focusing on S100A12 and highlights the current and potential roles of this biomarker.

Fecal phagocyte-specific S100A12 for diagnosing necrotizing enterocolitis

OBJECTIVE

To determine whether longitudinal measurements of fecal S100A12, a fecal marker of intestinal inflammation, can identify very low birth weight infants at risk for necrotizing enterocolitis (NEC).

STUDY DESIGN

This prospective study included 145 preterm infants with birth weight <1500 g. Meconium and stool samples (n = 843) were collected prospectively on alternate days for 4 weeks, and fecal S100A12 and calprotectin were measured by enzyme-linked immunosorbent assay.

RESULTS

Eighteen patients (12.4%) developed NEC. Gestational age and birth weight were significantly lower in the patients with NEC compared with unaffected reference infants. Fecal S100A12 levels were significantly higher in patients with severe NEC at onset of disease and also, in contrast to fecal calprotectin, at 4-10 days before onset of NEC compared with unaffected reference infants (ideal cutoff value, 65 μg/kg; sensitivity, 0.76; specificity, 0.56).

CONCLUSIONS

Fecal S100A12 level may be a helpful marker for predicting disease severity and early risk assessment for subsequent development of NEC. However, the use of fecal S100A12 as a predictive biomarker for NEC in very low birth weight infants may be limited due to a high interindividual and intraindividual variability in S100A12 fecal excretion.

Update of faecal markers of inflammation in children with cystic fibrosis

There is evidence of intestinal inflammation in patients with CF. Intestinal inflammation may negatively impact the nutritional status of patient with CF, which adversely affects pulmonary function and survival. This paper provides an up-to-date review of intestinal inflammation in CF and an evaluation of utility of two specific faecal inflammatory markers (S100A12 and calprotectin).

Fecal M2-PK in children with Crohn's disease: a preliminary report

BACKGROUND AND AIMS

Although active inflammatory changes in chronic Crohn's disease (CD) can be detected with serum inflammatory markers, these have low specificity and sensitivity. Stool markers of inflammation, such as M2-pyruvate kinase (M2-PK), permit more direct assessment of mucosal inflammation. The aim of this study was to assess levels of M2-PK in children with active CD and to compare to levels in healthy control children.

METHODS

Fecal levels of M2-PK were measured by immunoassay using stored stool samples from children with untreated (active) CD and healthy control children. Correlations between M2-PK levels and disease activity scores and serum inflammatory markers were performed. Comparison was also made between M2PK and a second fecal inflammatory marker, S100A12.

RESULTS

Mean fecal M2-PK levels were higher in the 17 patients with active CD than in the 21 healthy controls (p = 0.0007). M2-PK levels did not correlate with disease activity scores or serum inflammatory markers. There was a trend for children with ileocolonic disease to have higher levels of M2-PK in their stool compared to those with colonic disease or isolated ileal disease. Fecal M2PK did not correlate with fecal S100A12 in children with active CD.

CONCLUSION

Fecal M2-PK is increased in children with active CD, indicating that this marker may be a useful non-invasive marker for gut inflammation. Further studies of M2PK are required in additional settings with larger cohorts of children with CD and with comparison to other stool markers.

Faecal markers of gastrointestinal inflammation

Gastrointestinal (GI) symptoms including abdominal pain, bloating and diarrhoea are a relatively common reason for consulting a physician. They may be due to inflammatory bowel disease (inflammatory bowel disease; Crohn's disease, ulcerative colitis and indeterminate colitis), malignancy (colorectal cancer), infectious colitis or irritable bowel syndrome (IBS). Differentiation between these involves the use of clinical, radiological, endoscopic and serological techniques, which are invasive or involve exposure to radiation. Serological markers include C-reactive protein, erythrocyte sedimentation rate and antibodies (perinuclear antineutrophil cytoplasm antibody and anti-Saccharomyces cerevisiae antibody). Faecal markers that can aid in distinguishing inflammatory disorders from non-inflammatory conditions are non-invasive and generally acceptable to the patient. As IBS accounts for up to 50% of cases presenting to the GI clinic and is a diagnosis of exclusion (Rome III criteria), any test that can reliably distinguish IBS from organic disease could speed diagnosis and reduce endoscopy waiting times. Faecal calprotectin, lactoferrin, M2-PK and S100A12 will be reviewed.

Metabolome and inflammasome in inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses several chronic inflammatory disorders leading to the damage of the gastrointestinal tract. The 2 principal forms of these disorders are ulcerative colitis (UC) and Crohn's disease (CD). Bacteria are involved in the etiology of IBD. Many microorganisms have been put forward as causative factors in IBD, but the primary etiologic agents are still not known. The underlying genetic, environmental, and lifestyle issues can affect the individual's predisposition to these diseases. Immune factors identified in IBD are: dysregulation of the innate and adaptive immune system directed against luminal bacteria or their products found in the intestinal lumen and inappropriate immune responses to organisms in the intestine that normally do not elicit a response, possibly because of intrinsic alterations in mucosal barrier function. However, recent advances in basic science research revealed new insights into the role of specific immune cells and their mediators in intestinal inflammation. The inflammatory mediators known as "inflammasome" are a consequence of the metabolic products (metabolom) of cells and commensal or pathogenic bacteria. Elucidation of inflammasome and metabolom has led to the development of biomarkers specific for each disease that are involved into management strategies targeted at altering specific pathogenic mechanisms that have the potential to modify or change the natural course of these disease entities. The review discusses the potential role of biomarkers in monitoring the inflammasome and therefore the severity of intestinal damage. The microbial ecosystem in the human gut in different microhabitats and metabolic niches contribute to the bowel metabolome.In addition, this review will focus on our expanding understanding of microbial factors associated with both the initiation and maintenance of IBD. New insights acquired from murine genetic models of inflammatory bowel disease will also be discussed.

Respiratory disease and early serum S100A12 changes in very premature infants

AIM

The role of granulocyte-specific S100A12, a marker for inflammatory disorders, in newborn lung disease is unknown. We compared postnatal blood S100A12 concentrations against respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD).

METHODS

Blood samples from 92 newborns were collected on admission, 12 h, day 1, day 3-4 and day 7, and analysed for S100A12. IL-8 and IL-6 were assayed in 52 infants.

RESULTS

Infants with RDS were significantly more premature (median 27 vs. 34 weeks), more likely to receive antenatal corticosteroids (84% vs. 26%) and have lower neutrophil counts (median 2.4 vs. 3.8 × 10(9) /L) at admission. S100A12 levels peaked during the first day and were significantly lower in preterm infants with RDS compared to those without (median 250 vs. 616 ng/mL at 12 h, 281 vs. 828 ng/mL day 1, respectively). S100A12 levels were low among the 35 very preterm infants (24-29 week gestation) regardless of the presence of BPD (285 vs. 288 ng/mL on day 1). In comparison, IL-8 and IL-6 levels were not different between groups.

CONCLUSION

Plasma S100A12 is low in infants with RDS, possibly because of gestationally related differences in neutrophil response or to the effects of antenatal corticosteroids. It is therefore not a useful marker of BPD development.

Update of fecal markers of inflammation in inflammatory bowel disease

The diagnosis, prognosis, and assessment of disease activity of inflammatory bowel disease (IBD) require investigating clinical, radiological, and histological criteria, as well as serum inflammatory markers. However, a range of fecal inflammatory markers now appears to have the potential to greatly assist in these processes. Calprotectin, a prominent neutrophil protein, was identified two decades ago as a potentially revolutionary marker for IBD. Following this discovery, numerous additional markers, including S100A12, lactoferrin, and M2-pyruvate kinase, have also been suggested as novel markers of IBD. In the present study, we provide an up-to-date review of fecal markers of IBD, and further, provide a novel analysis of each of these fecal markers in severe ulcerative colitis and compare their expression pattern in contrast to calprotectin.

Calprotectin, calgranulin C, and other members of the s100 protein family in inflammatory bowel disease

BACKGROUND

Since their discovery, S100 proteins have been associated with diverse diseases of inflammatory, degenerative, or malignant nature. Due to their participation in inflammation, they have also been studied with regard to inflammatory bowel disease (IBD).

METHOD

To provide a review of available literature, a PubMed, MEDLINE, and Embase-based literature search was performed, using all available nomenclature for each member of the S100 protein family, along with the terms inflammatory bowel disease, ulcerative colitis, Crohn's disease, or indeterminate colitis.

RESULT

S100A8/A9, also known as calprotectin, S100A12, or calgranulin C and in a lesser extent S100P, are involved in the pathogenesis, activity, diagnosis, and therapeutic management of IBD. The majority of available literature is focused primarily on S100A8/9, although there is growing evidence on the significance of S100A12. Most studies emphasize the potential merit of S100A8/A9 and S100A12, as markers for differential diagnosis, monitoring of activity, or disease relapse, in IBD. Limitations, regarding the diagnostic utility of these markers, seem to exist and are mainly related to the publication of conflicting results, i.e., for IBD activity, and to the fact that S100A8/A9 and S100A12 are not disease-specific.

CONCLUSIONS

Although the existing data link specific S100 proteins with IBD, there are still several drawbacks in the use of these markers for diagnostic purposes. Thus, it seems that further research is mandatory in order to eliminate the impact of confounding factors but also to detect additional associations between S100 proteins and IBD or novel S100 proteins with a closer correlation with IBD.

The utility of biomarkers in the diagnosis and therapy of inflammatory bowel disease

Fecal and serologic biomarkers can be used in the diagnosis and management of inflammatory bowel disease (IBD). Fecal markers such as calprotectin and lactoferrin have been studied for their ability to identify patients with IBD, assess disease activity, and predict relapse. Antibodies against Saccharomyces cerevisiae and perinuclear antineutrophil cytoplasmic proteins have been used in diagnosis of IBD, to distinguish Crohn's disease (CD) from ulcerative colitis, and to predict the risk of complications of CD. Tests for C-reactive protein and erythrocyte sedimentation rate have been used to assess inflammatory processes and predict the course of IBD progression. Levels of drug metabolites and antibodies against therapeutic agents might be measured to determine why patients do not respond to therapy and to select alternative treatments. This review addresses the potential for biomarker assays to improve treatment strategies and challenges to their use and development.

Osteoprotegerin in pediatric Crohn's disease and the effects of exclusive enteral nutrition

BACKGROUND

Osteoprotegerin (OPG) may have proinflammatory roles in addition to its contribution to the maintenance of bone mass. Exclusive enteral nutrition (EEN) is an established therapy for the induction of remission in Crohn's disease (CD). The aims of this study were to ascertain serum, fecal, and mucosal expression of OPG in children with CD and to investigate the effects of EEN on OPG expression.

METHODS

OPG was measured by enzyme-linked immunosorbent assay in serum, mucosal, and fecal samples collected from children with CD and controls. Fecal and Serum OPG was measured prior to and following 6-8 weeks of EEN therapy.

RESULTS

Children with CD (n=82) and controls (n=45) were included. Mucosal and fecal OPG levels were elevated in CD compared to controls (P=0.018 and P<0.0001, respectively). Serum OPG was elevated in children with severe CD (P=0.005). Serum and fecal OPG levels dropped significantly following EEN therapy (P=0.0001 and P=0.002, respectively).

CONCLUSIONS

Increased serum and fecal OPG are seen in active CD and likely originate from the inflamed gut. Fecal and serum OPG decrease following EEN therapy. Further investigation of OPG and related proteins in the setting of IBD is now required.

Subclinical intestinal inflammation in siblings of children with Crohn's disease

BACKGROUND

Intestinal permeability and altered inflammatory responses, along with genetic and environmental factors, likely contribute to the pathogenesis of Crohn's disease.

AIMS

This study aimed to assess the presence and prevalence of subclinical intestinal inflammation among apparently healthy, first-degree relatives of pediatric patients with Crohn's disease, using non-invasive fecal markers.

METHODS

Stool samples were collected from 13 patients with Crohn's disease, 36 siblings and 41 parents. S100A12 levels were measured using an in-house ELISA assay and calprotectin levels were determined using the PhiCal test, with levels compared to normal healthy population controls.

RESULTS

Fecal S100A12 levels in siblings (median, 14 mg/kg; 95% confidence interval [CI], 9-32 mg/kg) and patients (71 mg/kg; CI 4-286 mg/kg) differed significantly from pediatric controls (1 mg/kg; CI 1-5 mg/kg; p < 0.001). In contrast, fecal calprotectin levels in siblings (22 mg/kg; CI 15-31 mg/kg) were lower than that of pediatric controls (31 mg/kg; CI 19-52 mg/kg; p = 0.03). Fecal markers were not elevated in parents compared to adult controls.

CONCLUSIONS

This study provides further evidence of subclinical intestinal inflammation amongst first-degree relatives of patients with Crohn's disease. The presence of sub-clinical gut inflammation may be a risk factor for the subsequent development of Crohn's disease.

Moderate performance of serum S100A12, in distinguishing inflammatory bowel disease from irritable bowel syndrome

Background

S100A12, a calcium-binding proinflammatory protein secreted by granulocytes, has been associated with different diseases of inflammatory origin, including inflammatory bowel disease (IBD). In this study, the utility of serum S100A12, in discriminating IBD from irritable bowel syndrome (IBS), was tested.

Methods

S100A12 serum levels were determined in 64 patients with ulcerative colitis (UC), 64 with Crohn's disease (CD) and 73 with IBS, by means of an enzyme-linked immunosorbent assay. S100A12 serum levels were evaluated with respect to the levels of known inflammatory markers and patients' characteristics.

Results

The median values of serum S100A12 levels were 68.2 ng/mL (range: 43.4-147.4) in UC, 70 ng/mL (41.4-169.8) in CD and 43.4 ng/mL (34.4-74.4) in IBS patients. UC and CD patients had significantly higher serum S100A12 levels compared to IBS patients (P = 0.001 for both comparisons). Moreover, a cut-off for serum S100A12 levels of 54.4 ng/mL could predict both UC and CD with a 66.7% sensitivity and a 64.4% specificity. The area under curve was estimated at 0.67 with a 95% confidence interval of 0.60-0.75 (P < 0.001). Considering standard activity indices, higher serum S100A12 levels in active compared to inactive IBD were observed, although the recorded difference did not reach statistical significance. C-reactive protein (CRP) and serum amyloid A (SAA) levels, showed a statistically significant positive correlation with S100A12 (r = 0.39, P = 0.001 and r = 0.23, P = 0.02 respectively).

Conclusions

Increased levels of circulating S100A12 are found in IBD, compared to IBS. When used to distinguish IBD from IBS adult patients, serum S100A12 levels exhibit moderate performance. On the other hand, serum S100A12 may serve as an inflammatory marker in IBD, since it is well correlated with CRP and SAA.

C-reactive protein and disease activity in children with Crohn's disease

BACKGROUND AND AIMS

Various markers are used to monitor disease activity in paediatric Crohn's disease (CD). We sought to determine whether C-reactive protein measurement was useful in the assessment of disease activity in children with CD, with comparison to the other markers of disease activity.

METHODS

Details of disease activity, C-reactive protein and inflammatory markers were obtained retrospectively from the records of 100 outpatient visits by 63 children with CD.

RESULTS

The children were 12.6 (+/-3.4) years of age. C-reactive protein values correlated positively with disease activity (P < 0.0001). Children with inactive disease (according to pediatric CD activity index scores) had significantly lower C-reactive protein values compared to children with mild disease (P < 0.001). In addition, C-reactive protein values correlated well with ESR (P < 0.0001). Conclusions C-reactive protein measurements provided useful information in assessing children with CD and correlated well with a validated measure of disease activity.

Overview of inflammatory bowel disease in Australia in the last 50 years

Inflammatory diseases of the intestine, including Crohn's disease, ulcerative colitis, and celiac disease are now very common in Australia and remain major challenges for clinicians. Australian (and New Zealand) clinicians and scientists have made considerable contributions to our current understanding of these diseases over the last 50 years, including pathogenesis (such as the 'butyrate hypothesis', 'endoplasmic reticulum (ER) stress', and the identification of the peptide sequences that incite celiac disease), true population epidemiology (albeit in New Zealand), precise clinical observation, new investigative tools, innovative new potential therapies, influential clinical drug trials (such as triple antibiotics for Crohn's disease), and a dietary approach with efficacy for functional gut symptoms (the low FODMAP diet). Underpinning the success has been clinical excellence and adaptation of clinicians to the changing landscape of disease severity and therapeutic options. The future is indeed bright if such trends continue.

Fecal calprotectin and lactoferrin as noninvasive markers of pediatric inflammatory bowel disease

OBJECTIVE

To evaluate whether fecal calprotectin (FC) and fecal lactoferrin (FL) can be used as noninvasive markers in children and young people (4-17 years) with active inflammatory bowel disease (IBD).

PATIENTS AND METHODS

Stool samples were collected from 3 groups of children: those with active IBD, control individuals with other gastrointestinal (GI) diseases (GI control) and control individuals with no GI disease (non-GI control). The number of patients for the FC assay was as follows: IBD = 26, GI control = 30, non-GI control = 25. The number of patients for the FL assay was as follows: IBD = 24, GI control = 26, non-GI = 24. FC and FL were measured by use of enzyme-linked immunoassays.

RESULTS

The median concentrations of FC and FL in isolation, and their interaction, were significantly higher in the IBD group than in the GI and non-GI control groups (P < 0.001). Although the area under the curve, sensitivity, and specificity for FC, FL, and FC x FL interaction were significantly better than chance, FL consistently had the lowest area under the curve, and FC x FL consistently had the highest area under the curve.

CONCLUSIONS

FC and FL are both significantly elevated in children with IBD, and the interaction of these 2 biomarkers may produce a better initial diagnostic test compared with their use in isolation.

Improved diagnosis of colorectal cancer using a combination of fecal occult blood and novel fecal protein markers

BACKGROUND & AIMS

Annual testing for fecal occult blood is recommended as first-line screening for the detection of colorectal cancer (CRC), but is affected by limited sensitivity. We initiated a proteomics-based search for novel biomarkers to improve the sensitivity of detection of CRC in stool samples.

METHODS

Six markers, including immunologic fecal occult blood test (iFOBT), were evaluated in a collective of 551 samples (186 CRC, 113 advanced adenoma, and 252 control patients) to establish the diagnostic performance of each marker and marker combinations.

RESULTS

We tested the known stool markers hemoglobin (iFOBT), hemoglobin-haptoglobin, calprotectin, carcinoembryogenic antigen, and the novel fecal markers tissue inhibitor of metalloproteinase-1 (TIMP-1) and S100A12. The best diagnostic performance was found for S100A12 with an area under the curve of 0.95, followed by TIMP-1 (0.92), hemoglobin-haptoglobin (0.92), hemoglobin (0.91), calprotectin (0.90), and carcinoembryogenic antigen (0.66). By using Bayes logistic regression as a mathematic model, the highest sensitivity (88%) for the detection of CRC at 95% specificity was obtained with the marker pair S100A12 and hemoglobin-haptoglobin. Increasing the specificity to 98%, the combination of S100A12, hemoglobin-haptoglobin, and TIMP-1 resulted in a sensitivity of 82%, with the highest increase of sensitivity found in early tumor stages (international union against cancer stage I: 74% sensitivity vs 57% of the best single marker).

CONCLUSIONS

Depending on the specificity selected, a marker pair, S100A12 and hemoglobin-haptoglobin, or a triple combination including TIMP-1, allowed the detection of CRC at significantly higher rates than can be obtained with iFOBT alone.

Sustained modulation of intestinal bacteria by exclusive enteral nutrition used to treat children with Crohn's disease

BACKGROUND

The use of exclusive enteral nutrition to treat paediatric Crohn's disease (CD) is widely accepted, although the precise mechanism(s) of action remains speculative.

AIM

To investigate the changes to key intestinal bacterial groups of Eubacteria, Bacteroides, Clostridium coccoides, Clostridium leptum and Bifidobacteria, during and after exclusive enteral nutrition treatment for CD in paediatric patients and correlate these changes to disease activity and intestinal inflammation.

METHODS

Stool was collected from six children at diagnosis of CD, during exclusive enteral nutrition and 4 months post-therapy, and from seven healthy control children. The diversity of bacteria was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis with changes to bacterial diversity measured by Bray-Curtis similarity, intestinal inflammation assessed by faecal S100A12 and the disease activity assessed by PCDAI.

RESULTS

A significantly greater change in intestinal bacterial composition was seen with exclusive enteral nutrition treatment compared with controls. Further, the intestinal bacteria remained altered 4 months following exclusive enteral nutrition completion. Changes in the composition of Bacteroides were associated with reduced disease activity and inflammation.

CONCLUSIONS

Exclusive enteral nutrition reduces bacterial diversity and initiates a sustained modulation of all predominant intestinal bacterial groups. Exclusive enteral nutrition may reduce inflammation through modulating intestinal Bacteroides species. The implications of these results for exclusive enteral nutrition therapy and CD pathogenesis should now be the subject of further investigation.

Fecal S100A12 and fecal calprotectin as noninvasive markers for inflammatory bowel disease in children

BACKGROUND

Fecal calprotectin is a sensitive marker for gut inflammation. Recently, we have established that a related protein, S100A12, is elevated in the feces of children with inflammatory bowel disease (IBD). This may represent a specific and sensitive disease marker. The objective was to investigate the utility of fecal S100A12, in comparison to fecal calprotectin and standard inflammatory markers, as a screening marker for IBD in children with gastrointestinal symptoms.

METHODS

Stool samples were obtained from 61 children presenting with gastrointestinal symptoms requiring endoscopy. Fecal S100A12, calprotectin, and serum S100A12 levels were measured and correlated to final diagnosis and standard tests (ESR, CRP, platelet count, and albumin).

RESULTS

Children diagnosed with IBD (n = 31) had elevated fecal S100A12 (median 55.2 mg/kg) and calprotectin (median 1265 mg/kg) levels compared with the children without IBD (n = 30; S100A12: median 1.1 mg/kg, P < 0.0001; calprotectin: median 30.5 mg/kg; P < 0.0001). The sensitivity and specificity of fecal S100A12 (cutoff 10 mg/kg) for the detection of IBD were both 97%, whereas fecal calprotectin (cutoff 50 mg/kg) gave a sensitivity of 100% and a specificity of 67%.

CONCLUSIONS

Both fecal markers were superior to the sensitivities and specificities of any standard inflammatory test. Both fecal S100A12 and calprotectin are sensitive markers of gastrointestinal inflammation, but fecal S100A12 provided exceptional specificity in distinguishing children with IBD from children without IBD. Fecal S100A12 is a simple, noninvasive test that can be used to screen and select children warranting further invasive and laborious procedures such as endoscopy for the investigation of their gastrointestinal symptoms.

Serum and mucosal S100 proteins, calprotectin (S100A8/S100A9) and S100A12, are elevated at diagnosis in children with inflammatory bowel disease

OBJECTIVE

Various markers characterize the complex inflammatory processes seen in chronic inflammatory bowel disease (IBD) including calprotectin, a complex of two S100 proteins, which has been evaluated and validated as a faecal marker of inflammation. However, the systemic and mucosal expression patterns of calprotectin and related S100 proteins are not well characterized in this disease. The objective of this study was to assess serum and mucosal levels of calprotectin, S100A12 and soluble receptor for advanced glycation end products (sRAGE), a putative S100 ligand, in a paediatric population with IBD.

MATERIAL AND METHODS

Children were enrolled at diagnosis of IBD, along with groups of children without IBD. Standard inflammatory markers and disease activity scores were collated. Calprotectin, S100A12 and sRAGE levels in serum and biopsy culture supernatants were measured by ELISA and tissue distribution of S100 proteins was investigated by immunohistochemistry.

RESULTS

Serum and mucosal calprotectin and S100A12 levels were increased in children with IBD as compared with non-IBD controls. Serum calprotectin levels correlated with S100A12 levels and with disease activity scores in children with IBD. sRAGE levels were not increased in IBD. S100A8, S100A9 and S100A12 were abundantly expressed throughout the lamina propria and epithelium in inflamed mucosa. In contrast, these proteins were present in the lamina propria, but not the epithelium, in non-inflamed mucosa.

CONCLUSIONS

Serum calprotectin and S100A12 are increased in children with IBD and indicate disease activity. Elevated levels of these proteins are present in the colonic mucosa and may contribute to the pathogenesis of IBD. Furthermore, an imbalance between sRAGE and S100A12 may contribute to inflammatory changes present in IBD.

Prospective evaluation of faecal neutrophil-derived proteins in identifying intestinal inflammation: combination of parameters does not improve diagnostic accuracy of calprotectin

BACKGROUND

Differentiating symptoms of irritable bowel syndrome from those of organic intestinal disease is a common clinical problem. Several neutrophil-derived proteins have been proposed as a marker of inflammatory bowel disease.

AIM

To compare the diagnostic value of faecal calprotectin, lactoferrin and polymorphonuclear neutrophil-elastase in distinguishing inflammatory bowel disease from irritable bowel syndrome.

METHODS

Eighty-eight adult patients with a history of chronic diarrhoea of unknown origin were screened. All patients underwent a complete work-up to identify the underlying cause. In addition, a single stool sample was assayed for faecal calprotectin, lactoferrin and polymorphonuclear neutrophil-elastase by enzyme-linked immunosorbent assay.

RESULTS

Within the study cohort inflammatory bowel disease was diagnosed in 45 patients and irritable bowel syndrome in 31 patients. The sensitivity and specificity of calprotectin for inflammatory bowel disease were 93% and 100%, respectively. In contrast, the respective diagnostic values for lactoferrin and polymorphonuclear neutrophil-elastase were 82% and 100% and 84% and 87%, respectively. Neither combination of markers did improve the diagnostic power compared with calprotectin alone.

CONCLUSIONS

Although all faecal biomarkers studied provide a reliable and simple non-invasive means in the differentiation of inflammatory bowel disease and irritable bowel syndrome, calprotectin appears to represent the most accurate marker to discriminate between these two common causes of chronic diarrhoea.

Enzymes in feces: useful markers of chronic inflammatory bowel disease

BACKGROUND

Ulcerative colitis and Crohn's disease are characterized by a chronic intestinal inflammation. Since the precise etiology is still unknown, current therapies are aimed at reducing or eliminating inflammation.

METHODS

Endoscopy and histology on biopsy specimens remain the gold standard methods for detecting and quantifying bowel inflammation. These technique are expensive, invasive and not well tolerated by patients since the need of repeated examinations affects their quality of life. Although disease activity scores and laboratory inflammatory markers are widely used they showed unreliable relations with endoscopy and histology. Fecal markers have been investigated in inflammatory bowel disease (IBD) by many authors for diagnostic purposes, to assess disease activity and of risk of complications, to predict relapse or recurrence, and to monitor the effect of therapy. Many inflammatory mediators have been detected in the feces such as leukocytes, cytokines and proteins from neutrophil activation. Some of these, particularly lactoferrin and calprotectin, have been demonstrated to be useful in detecting active inflammatory bowel disease, in predicting recurrence of disease after surgery or monitoring the effects of medical therapy. Calprotectin and lactoferrin are remarkably stable and easily detect in stool using ELISA so they appear to be equally recommendable as inflammation markers in the lower gastrointestinal tract especially in IBD patients.

CONCLUSION

Fecal markers are non-invasive, simple, cheap, sensitive and specific parameters and are useful to detect strointestinal inflammation.