Metabolic and inflammatory faecal markers in collagenous colitis

Does fecal calprotectin increase may be linked to lactose intolerance in patients with irritable bowel syndrome?

BACKGROUND

Irritable bowel syndrome (IBS) is a multifactorial condition without any specific investigation. Fecal calprotectin (FC) may be elevated in IBS without any explanation. In addition, some patients with IBS have symptoms related to lactose intolerance. Our main aim was to investigate whether an increase in FC could be related to lactose intolerance in patients with IBS.

METHODS

In this retrospective single-center study, all patients with IBS who have underwent a FC test and a lactose respiratory test within a period of less than 6 months were eligible. A FC greater than or equal to 50 μg/g was considered abnormal.

RESULTS

Severnty-six patients (48 females), mean age 38±15 years were included. Symptoms were respectively: bloating in 57%, diarrhea in 76% and abdominal pain in 46% of cases. Among the 76 patients: 22 (29%) had FC≥50 μg/g and 9/22 (41%) had a positive lactose test. No significant relationship could be identified between the increase in FC and the lactose test positivity. The value of the FC was also not related to the subtype of IBS or the positivity of the glucose test.

CONCLUSIONS

In our study, the increase in FC was not significantly related to the presence of lactose intolerance. Nevertheless, our work, despite its originality, is limited by its retrospective nature and small number of patients. Future studies including larger numbers of patients may identify the causes of elevated FC in patients with IBS to individualize different subgroups of patients to best adapt therapeutic management.

Microscopic Colitis: Pathogenesis and Diagnosis

Microscopic colitis is a type of inflammatory bowel disease and is classified as either collagenous colitis or lymphocytic colitis. The typical presentation is chronic watery diarrhea. The disease occurs more frequently in women aged 60-65 years and is increasing in incidence. The pathophysiology of microscopic colitis remains poorly understood and has not been well-described with possible several pathogeneses. To date, the diagnosis of microscopic colitis depends on histological tissue obtained during colonoscopy. Other non-invasive biomarkers, such as inflammatory markers and fecal biomarkers, have been studied in microscopic colitis, but the results remains inconclusive. The approach to chronic diarrhea is important and being able to differentiate chronic diarrhea in patients with microscopic colitis from other diseases, such as inflammatory bowel disease, functional diarrhea, and malignancy, by using non-invasive biomarkers would facilitate patient management. The management of microscopic colitis should be based on each individual's underlying pathogenesis and involves budesonide, bile acid sequestrants, or immunosuppressive drugs in refractory cases. Cigarette smoking and certain medications, especially proton pump inhibitors, should be eliminated, when possible, after the diagnosis is made.

Gut microbiota short-chain fatty acids and their impact on the host thyroid function and diseases

Thyroid disorders are clinically characterized by alterations of L-3,5,3',5'-tetraiodothyronine (T4), L-3,5,3'-triiodothyronine (T3), and/or thyroid-stimulating hormone (TSH) levels in the blood. The most frequent thyroid disorders are hypothyroidism, hyperthyroidism, and hypothyroxinemia. These conditions affect cell differentiation, function, and metabolism. It has been reported that 40% of the world's population suffers from some type of thyroid disorder and that several factors increase susceptibility to these diseases. Among them are iodine intake, environmental contamination, smoking, certain drugs, and genetic factors. Recently, the intestinal microbiota, composed of more than trillions of microbes, has emerged as a critical player in human health, and dysbiosis has been linked to thyroid diseases. The intestinal microbiota can affect host physiology by producing metabolites derived from dietary fiber, such as short-chain fatty acids (SCFAs). SCFAs have local actions in the intestine and can affect the central nervous system and immune system. Modulation of SCFAs-producing bacteria has also been connected to metabolic diseases, such as obesity and diabetes. In this review, we discuss how alterations in the production of SCFAs due to dysbiosis in patients could be related to thyroid disorders. The studies reviewed here may be of significant interest to endocrinology researchers and medical practitioners.

Fecal calprotectin level in microscopic colitis: a systematic review and meta-analysis

Background

There are no specific biomarkers for microscopic colitis (MC), and the diagnosis depends on histopathological tissue obtained during colonoscopy. Studies on the role of fecal calprotectin (FCP) in MC are limited. A literature search of PubMed, Embase, and Scopus was conducted from each database's inception through September 2022.

Methods

A DerSimonian-Liard random-effects meta-analysis was performed to examine the standardized mean difference (SMD) in FCP levels between patients with MC and control patients with chronic diarrhea.

Results

Six studies with 96 active MC patients and 200 controls were included in the meta-analysis. Random effects meta-analysis revealed that FCP was significantly and moderately elevated in patients with MC compared to the control group (SMD = 0.6 [95% CI 0.3, 1.0], P = 0.001). Imputing one effect size confirmed the observation that FCP is significantly higher in patients with MC than control subjects with chronic diarrhea (SMD = 0.5 [95% CI 0.2, 0.9], P = 0.004). Study heterogeneity between the SMDs was not significant (I2 = 41%, P = 0.1).

Conclusion

These results indicate that FCP levels in patients with chronic diarrhea can help identify patients with MC. More studies with serial measurements of FCP would provide a better understanding of its utility in MC.

Fecal Calprotectin in Self-Reported Milk Intolerance: Not Only Lactose Intolerance

The hypothesis is that inflammatory/allergic conditions should be considered in self-reported milk intolerance (SRMI) patients who test negative and/or are asymptomatic at Lactose Hydrogen Breath Test (LHBT). We analyzed fecal calprotectin (FCP) values in SRMI patients to investigate the frequency of a "positive" intestinal inflammation marker and its correlation with lactose tolerance/intolerance. Data from 329 SRMI patients were retrospectively analyzed; according to the positive/negative results (maldigester/digester) and the presence/absence of symptoms reported during LHBT (intolerant/tolerant), patients were divided into: 'lactose tolerants' (n. 104), 'maldigesters/intolerants' (n. 187), 'digesters/intolerants' (n. 38). FCP values were analyzed in all three subgroups. A percentage of SRMI patients complained of constipation (>15%), extraintestinal symptoms (>30% including anemia), multiple food hypersensitivity (7.6%) and had intraepithelial lymphocytic infiltration at duodenal biopsy (>50%). Over 50.0% showed FCP values above the normal limit. Lactose tolerants and maldigesters/intolerants had higher positivity frequencies (p < 0.0001, for both) and absolute values (p = 0.04, for maldigesters/intolerants) of FCP compared to digesters/intolerants. FCP was not useful to differentiate tolerant from intolerant subjects (AUC 0.58). Our data suggest the existence of an allergic/inflammatory pathogenetic mechanism in a subset of SRMI subjects. FCP results are in keeping with this hypothesis, even if they cannot differentiate lactose tolerant from intolerant patients.

Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility

Irritable bowel syndrome with diarrhoea (IBS‐D) and functional diarrhoea (FDr) are the two major functional bowel disorders characterized by diarrhoea. In spite of their high prevalence, IBS‐D and FDr are associated with major uncertainties, especially regarding their optimal diagnostic work‐up and management. A Delphi consensus was performed with experts from 10 European countries who conducted a literature summary and voting process on 31 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation criteria. Consensus (defined as >80% agreement) was reached for all the statements. The panel agreed with the potential overlapping of IBS‐D and FDr. In terms of diagnosis, the consensus supports a symptom‐based approach also with the exclusion of alarm symptoms, recommending the evaluation of full blood count, C‐reactive protein, serology for coeliac disease, and faecal calprotectin, and consideration of diagnosing bile acid diarrhoea. Colonoscopy with random biopsies in both the right and left colon is recommended in patients older than 50 years and in presence of alarm features. Regarding treatment, a strong consensus was achieved for the use of a diet low fermentable oligo‐, di‐, monosaccharides and polyols, gut‐directed psychological therapies, rifaximin, loperamide, and eluxadoline. A weak or conditional recommendation was achieved for antispasmodics, probiotics, tryciclic antidepressants, bile acid sequestrants, 5‐hydroxytryptamine‐3 antagonists (i.e. alosetron, ondansetron, or ramosetron). A multinational group of European experts summarized the current state of consensus on the definition, diagnosis, and management of IBS‐D and FDr.

Diagnosis and Management of Microscopic Colitis in Pediatric Patients

Microscopic colitis (MC) is an inflammatory disease of the colon, characterized by chronic watery diarrhea with distinguishing histologic findings despite normal endoscopic appearance of the colonic mucosa. MC is a common cause of diarrhea in older adults, though it has been infrequently reported in children and adolescents. As MC is rare in the pediatric population, and the clinical presentation is non-specific, increased awareness of this disease amongst pediatric clinicians and pathologists is essential for timely diagnosis, which requires performing colonoscopy with biopsy. The etiology of MC is incompletely understood, but current theories in pathogenesis inform management strategies. The goals of management in pediatric MC should be to achieve symptomatic improvement while minimizing adverse effects of treatment. Many patients who achieve clinical response have symptomatic recurrence after discontinuation of initial therapy, and may require maintenance medication therapy to sustain remission. This review aims to summarize the epidemiology and risk factors, clinical features, diagnosis, theories regarding pathogenesis, and suggested management approaches for MC in the pediatric population.

Endoscopic and histopathologic features of Anti‐PD‐1‐related collagenous colitis

Objectives

Cancer patients treated with immune checkpoint inhibitors occasionally show persistent diarrhea accompanied by endoscopic features of ulcerative colitis. The endoscopic mucosal inflammation may appear mild in some patients compared to the clinical severity, which can make choosing a treatment challenging. In this study, we evaluated the factors that support the continuation of chemotherapy by assessing the endoscopic and histopathological characteristics of patients who experienced diarrhea after immune checkpoint inhibitor administration.

Methods

This study included eight patients who were diagnosed with collagenous colitis based on pathological assessments. We retrospectively investigated these patients’ backgrounds, laboratory data, and computed tomography images that were extracted from their medical records. We also summarized their endoscopic and pathologic findings.

Results

All eight patients were being treated with anti‐programmed cell death‐1/programmed cell death‐ligand 1 therapeutic agents and had a recent history of oral proton pump inhibitor therapy. The anti‐programmed cell death‐1‐related collagenous colitis in these cases was characterized by endoscopically mild mucosal inflammation, high fecal calprotectin levels, and a lower frequency of intestinal wall thickening on computed tomography. Histological assessments showed CD8⁺ lymphocytes predominantly infiltrating the lamina propria and crypts of the colonic mucosa. Suspending the proton pump inhibitor therapy relieved the patients’ symptoms and allowed the continuation of the anti‐programmed cell death‐1/programmed cell death‐ligand 1 therapy.

Conclusions

Anti‐programmed cell death‐1‐related collagenous colitis is reversible; appropriate diagnosis of adverse events is crucial for the continuation of immune checkpoint inhibitor therapy.

Mucosal and faecal neutrophil gelatinase-associated lipocalin as potential biomarkers for collagenous colitis

BACKGROUND

Collagenous colitis (CC) is an inflammatory bowel disease where chronic diarrhoea is the main symptom. Diagnostic markers distinguishing between CC and other causes of chronic diarrhoea remain elusive. This study explores neutrophil gelatinase-associated lipocalin (NGAL) and its mRNA lipocalin2 (LCN2) as histological and faecal disease markers in CC.

METHODS

NGAL/LCN2 were studied in colonic biopsies from CC patients before and during budesonide treatment using RNA sequencing (n = 9/group), in situ hybridization (ISH) (n = 13-22/group) and immunohistochemistry (IHC) (n = 14-25/group). Faecal samples from CC (n = 3-28/group), irritable bowel syndrome diarrhoea (IBS-D) (n = 14) and healthy controls (HC) (n = 15) were assayed for NGAL and calprotectin.

RESULTS

NGAL/LCN2 protein and mRNA expression were upregulated in active CC vs HC, and vs paired samples of treated CC in clinical remission. IHC and ISH localized increased NGAL/LCN2 mainly to epithelium of active CC, compared to almost absence in HC and treated CC. In contrast, calprotectin was solely expressed in immune cells. Despite great individual differences, faecal NGAL was significantly increased in active CC compared to HC, IBS-D and treated CC and had high test sensitivity. Faecal calprotectin levels were variably increased in active CC, but the values remained below usual clinical cut-offs.

CONCLUSION

NGAL/LCN2 is upregulated in the epithelium of active CC and reduced during budesonide-induced clinical remission to the level of HC and IBD-S. This was reflected in NGAL faecal concentrations. We propose NGAL as an IHC marker for disease activity in CC and a potential faecal biomarker discriminating CC from HC and IBS-D.

Microscopic colitis

Microscopic colitis (MC) is an inflammatory disease of the large intestine associated with urgent watery diarrhoea. MC may occur in people of all ages, although the disease primarily affects older women. Once believed to be rare, MC is now known to be a common cause of chronic watery diarrhoea in high-income countries, affecting 1 in 115 women and 1 in 286 men during their lifetime in Swedish population-based estimates. An inappropriate immune response to disturbances in the gut microenvironment is implicated in the pathogenesis of MC. Evidence also supports an underlying genetic basis for disease. The diagnosis of MC relies on clinical symptoms and microscopic assessment of colonic biopsy samples. MC is categorized histologically into collagenous colitis, lymphocytic colitis and their incomplete forms. The mainstay of treatment includes the use of budesonide, with or without adjunctive therapies, and withdrawal of offending drugs. Emerging studies suggest a role for biologicals and immunosuppressive therapies for the management of budesonide-refractory or budesonide-dependent disease. MC can have a substantial negative effect on patient quality of life. The outlook for MC includes a better understanding of the immune response, genetics and the microbiome in disease pathogenesis along with progress in disease management through robust clinical trials.

Diagnostic accuracy of fecal calprotectin in predicting significant gastrointestinal diseases

Background and Aim

It is often unreliable to triage patients for timely endoscopic investigations based on symptoms alone. We need an objective assessment to differentiate between organic gastrointestinal diseases and functional bowel symptoms. We evaluated the diagnostic accuracy of fecal calprotectin (FC) in predicting organic gastrointestinal diseases.

Methods

In a prospective observational study, consecutive patients referred for colonoscopy to the Department of Medicine and Geriatrics at the Kwong Wah Hospital in Hong Kong were recruited. Stool samples were collected within 24 h before colonoscopy. FC was measured by a commercial kit. Upper endoscopy investigations were then proceeded if normal colonoscopy but elevated FC.

Results

Two hundred and seventy out of 429 patients had FC above 50 μg/g. Eighty‐six out of 270 with elevated FC had significant colonoscopy pathological findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FC test for diagnosing a significant organic colonoscopy or upper endoscopy disease were 91.7, 55.6, 57.0, and 91.2%, respectively. The NPV of FC for colorectal cancer, high risk polyp, and colon inflammation were 98.7, 96.2, and 98.1%, respectively. The NPV of FC in the condition of altered bowel habit or abdominal pain in predicting colorectal cancer and inflammation were 93.8 and 100%, respectively.

Conclusions

FC is a reliable marker of ruling out organic bowel diseases. A single negative FC test could be used as a triage tool to prioritize the need and urgency of further investigation, particularly in the setting of altered bowel habits and abdominal pain.

European guidelines on microscopic colitis: United European Gastroenterology and European Microscopic Colitis Group statements and recommendations

INTRODUCTION

Microscopic colitis is a chronic inflammatory bowel disease characterised by normal or almost normal endoscopic appearance of the colon, chronic watery, nonbloody diarrhoea and distinct histological abnormalities, which identify three histological subtypes, the collagenous colitis, the lymphocytic colitis and the incomplete microscopic colitis. With ongoing uncertainties and new developments in the clinical management of microscopic colitis, there is a need for evidence-based guidelines to improve the medical care of patients suffering from this disorder.

METHODS

Guidelines were developed by members from the European Microscopic Colitis Group and United European Gastroenterology in accordance with the Appraisal of Guidelines for Research and Evaluation II instrument. Following a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of the evidence. Statements and recommendations were developed by working groups consisting of gastroenterologists, pathologists and basic scientists, and voted upon using the Delphi method.

RESULTS

These guidelines provide information on epidemiology and risk factors of microscopic colitis, as well as evidence-based statements and recommendations on diagnostic criteria and treatment options, including oral budesonide, bile acid binders, immunomodulators and biologics. Recommendations on the clinical management of microscopic colitis are provided based on evidence, expert opinion and best clinical practice.

CONCLUSION

These guidelines may support clinicians worldwide to improve the clinical management of patients with microscopic colitis.

Faecal Calprotectin and 7-α Cholestenone Levels in Microscopic Colitis: Experience from Edinburgh

Introduction

Microscopic colitis (MC) is an important cause of chronic, watery diarrhoea. Currently, there is no specific biomarker available to guide diagnosis. The use of faecal calprotectin (FCP) as a potential marker has been addressed in only a few studies. Further, bile acid malabsorption (BAM) often accompanies MC. Current practice recommends the selenium-labelled homocholic acid-taurine (SeHCAT) test, but at our centre, 7 alpha-hydroxy-4-cholesten-3-one (7αC) is used as a simpler and less expensive alternative to SeHCAT, with values over 22ng/mL indicating BAM. This study aims to evaluate the use of FCP as a biomarker in the diagnosis of MC and the role of 7αC in detecting concomitant BAM with MC.

Methods

Pathology records were retrospectively reviewed for patients diagnosed with collagenous colitis (CC) between 2000 and 2018 and lymphocytic colitis (LC) between 1995 and 2011. FCP and 7αc results, if measured within 6 months of pathological diagnosis, were extracted for analysis.

Results

Between 2000 and 2018, 646 CC cases were confirmed on histology. Of 646 patients, 147 had FCP measured; in 111 (75.5%) FCP was elevated with mean levels 238.1μg/g (SD±273.0); 140/646 had 7αC measured; 16 (11.4%) indicated BAM. Mean levels were 10.2ng/mL (SD±9.4). During a 21-year period (1995–2011), 204 LC diagnoses were made: 14/204 had FCP measured; 8 (57.1%) were elevated. Mean levels were 128.4μg/g (SD±107.7). Of 204 LC patients, 20 had 7αC measured, 5 (25%) indicating BAM. Mean levels were 13.95ng/mL (SD±9.4).

Discussion

Both CC and LC were associated with raised FCP during the diagnostic phase, supporting the potential role of its use in clinical practice. Furthermore, we present results of using 7αC in identifying BAM amongst patients with MC. In our cohort, low levels of 7αC suggest relatively low concordance of BAM with MC.

Development and validation of a GC-FID method for the analysis of short chain fatty acids in rat and human faeces and in fermentation fluids

Short-chain fatty acids (SCFAs) are gut microbiota metabolites recognized for their beneficial effects on the host organism. In this study, a simple and rapid sample preparation method combined to SCFAs analysis by direct injection and gas chromatography coupled with flame ionization detection (GC-FID), for the determination and quantification of eight SCFAs (acetic, propionic, i-butyric, butyric, i-valeric, valeric, i-caproic and caproic acids) in rat, mice and human faeces and in fermentation fluids samples, has been developed and validated. The method consists of extraction of the SCFAs by ethyl ether after acidification of the samples. The effect of the number of extractions has been assessed in order to optimize the procedure and to obtain a satisfactory yield for all the analyzed SCFAs. The increase of the extracted analytes quantity was significant passing from 1 to 2 and from 2 to 3 extractions (P < 0.05), while no significant differences were found performing 3, 4 or 5 extractions (P > 0.05). The SCFAs extracted are directly analyzed by GC-FID without derivatization and separated on a polyethylene glycol nitroterephthalic acid modified coated capillary column, with a chromatographic run time of 13 min. The proposed method showed good sensitivity, with limits of quantifications in the range 0.14-0.48 µM for SCFAs from propionic to caproic acids and 2.12 µM for acetic acid; recovery was between 80.8 and 108.8% and intraday and interday repeatability in the range 0.6-5.0% of precision (RSD, %) The optimized method is suitable for the quantitative analysis of SCFAs in real samples of rat, mouse and human faeces and in fermentation fluids, and it can be applied also to very small amount of faecal sample (20 mg).

Undiagnosed microscopic colitis: a hidden cause of chronic diarrhoea and a frequently missed treatment opportunity

Microscopic colitis (MC) is a treatable cause of chronic, non-bloody, watery diarrhoea, but physicians (particularly in primary care) are less familiar with MC than with other causes of chronic diarrhoea. The colon in patients with MC is usually macroscopically normal. MC can only be diagnosed by histological examination of colonic biopsies (subepithelial collagen band >10 µm (collagenous colitis) or >20 intraepithelial lymphocytes per 100 epithelial cells (lymphocytic colitis), both with lamina propria inflammation). The UK National Health Service exerts downward pressure to minimise colonoscopy referrals. Furthermore, biopsies are often not taken according to guidelines. These factors work against MC diagnosis. In this review, we note the high incidence of MC (comparable to ulcerative colitis and Crohn's disease) and its symptomatic overlap with irritable bowel syndrome. We also highlight problems with the recommendation by National Health Service/National Institute for Health and Care Excellence guidelines for inflammatory bowel diseases that colonoscopy referrals should be based on a faecal calprotectin level of ≥100 µg/g. Faecal calprotectin is <100 µg/g in over half of individuals with active MC, building into the system a propensity to misdiagnose MC as irritable bowel syndrome. This raises important questions-how many patients with MC have already been misdiagnosed, and how do we address this silent burden? Clarity is needed around pathways for MC management; MC is poorly acknowledged by the UK healthcare system and it is unlikely that best practices are being followed adequately. There is an opportunity to identify and treat patients with MC more effectively.

Usefulness of fecal calprotectin as a biomarker of microscopic colitis in a cohort of patients with chronic watery diarrhoea of functional characteristics

BACKGROUND

Information on the use of fecal markers in microscopic colitis screening is limited.

AIM

To evaluate the risk variables associated with a diagnosis of microscopic colitis including fecal calprotectin.

METHODS

Patients submitted for a colonoscopy due to chronic watery diarrhea fulfilling criteria of functional disease were evaluated. Colonic mucosa was normal but mild erythema and edema was allowed. Fecal calprotectin was analyzed. A logistic regression was used to evaluate variables associated with both raised fecal calprotectin and a diagnosis of microscopic colitis.

RESULTS

94 patients were included, 30 were diagnosed with microscopic colitis and 64 made up the control group. Median calprotectin levels were 175 (IQR, 59-325) for the microscopic colitis and 28 (IQR, 16-111) for the control group (p < 0.001). The optimal cut-off for fecal calprotectin was >100 μg/g (AUC, 0.73), with 67% sensitivity and 75% specificity. The number of drugs used ≥3 (OR, 3.9; CI, 1.4-10.4) and microscopic colitis diagnosis (OR, 6; CI, 2.2-16.3) were associated with raised calprotectin levels. Age >60 years (OR, 3.8; CI, 1.4-10.1) and calprotectin levels (OR, 5.3; CI, 2-14.1) were associated with a risk of microscopic colitis.

CONCLUSIONS

Elevated fecal calprotectin concentrations are often seen in microscopic colitis, and may be helpful in the diagnosis of women over 60 with chronic watery diarrhea.

Microscopic colitis: diagnosis and management

Microscopic colitis (MC) is a common cause of chronic, non-bloody, watery diarrhoea in older patients. The diagnosis depends on characteristic histological findings. Bile acid malabsorption and autoimmune conditions, including coeliac disease, are more frequently found in patients with MC, but colorectal neoplasia and mortality are not increased. Non-steroidal anti-inflammatory drugs, proton-pump inhibitors, selective serotonin reuptake inhibitors and smoking tobacco confer an increased risk of developing MC. Although a so-called benign disease, which rarely causes serious complications, it does have an impact on the quality of life. Several treatment options exist, but budesonide is the only treatment proven in randomised-controlled trials to be effective and safe for induction and maintenance of remission. This article provides a practical overview for the gastroenterologist looking after patients with MC.

Clinical utility of fecal calprotectin: potential applications beyond inflammatory bowel disease for the primary care physician

Fecal calprotectin (FC) is an inflammatory marker released mainly from gastrointestinal granulocytes measured in stool samples. FC is noninvasive, economical, simple, and acceptable for patients. Levels of FC have proven reliable for intestinal inflammation, with good clinical sensitivity, and are useful in screening and monitoring inflammatory bowel disease (IBD), as well as in the differential diagnosis between IBD and irritable bowel syndrome (IBS). Given its advantages, FC represents an attractive biomarker that could be utilized in various gastrointestinal (GI) diseases apart from IBD, and is currently being studied extensively by many research groups with significant amounts of data emerging. In this current review we aim to provide an outline of the utility of FC in distinguishing between IBS and IBD, as well as an up-to-date summary of the available clinical experience concerning FC in various common conditions of the GI tract commonly encountered by gastroenterology practitioners, such as IBS, microscopic colitis, acute gastroenteritis, Clostridium difficile infection, colorectal cancer, diverticular disease, coeliac disease, and other GI conditions.

The role of fecal calprotectin in pediatric disease

Fecal calprotectin (FC) is a calcium- and zinc-binding protein of the S100 family, mainly expressed by neutrophils and released during inflammation. FC became an increasingly useful tool both for gastroenterologists and for general practitioners for distinguishing inflammatory bowel disease (IBD) from irritable bowel syndrome. Increasing evidences support the use of this biomarker for diagnosis, follow-up and evaluation of response to therapy of several pediatric gastrointestinal diseases, ranging from IBD to nonspecific colitis and necrotizing enterocolitis. This article summarizes the current literature on the use of FC in clinical practice.

Microscopic colitis: a narrative review with clinical approach

Microscopic colitis (MC) is diagnosed in presence of microscopic alterations of colonic mucosa, in patients without macroscopic lesions who referred for chronic diarrhea. The two types of MC are lymphocytic colitis (LC) and collagenous colitis (CC), but it is unclear whether these are the different expression of one unique disease or if they are distinct conditions. Today, although MC represents a consistent health problem, being responsible for a large part of gastroenterological consultations for diarrhea, it remains often underestimated. The detailed pathogenesis of MC has not been determined yet. Probably, it is the result of an interaction between individual, environmental and genetic factors. The most relevant risk factor for the development of MC is the use of certain drugs (such as non-steroidal anti-inflammatory drugs [NSAIDs], proton pump inhibitors [PPIs], selective serotonin reuptake inhibitors, beta-blockers, statins). Smoking is another relevant factor reported as associated with the development of MC. Diagnosis needs the execution of a colonoscopy in patients complaining about chronic diarrhea and abdominal pain. The crucial role is played by histology: MC is characterized by the presence of colonic mucosal lymphocytic infiltrate, with intraepithelial lymphocytes ≥20 per 100 enteric surface cells, in CC there is a typical subepithelial collagen layer, whose thickness is ≥10 μm. We carried out a review of the current literature to rule out what is new on epidemiology, diagnosis and therapy of MC.

Management of microscopic colitis: challenges and solutions

Microscopic colitis (MC) is a chronic inflammatory bowel disease characterized by nonbloody diarrhea in the setting of normal appearing colonic mucosa. MC has two main subtypes based on histopathologic features, collagenous colitis and lymphocytic colitis. Management of both subtypes is the same, with treatment goal of reducing the number of bowel movements and improving consistency. First-line treatment involves counseling the patient about decreasing their risk factors, like discontinuing smoking and avoiding medications with suspected association such as NSAIDs, proton pump inhibitor, ranitidine, and sertraline. Starting loperamide for immediate symptomatic relief is used as an adjunct to therapy with glucocorticoids. Budesonide is considered first-line treatment for MC given its favorable side effect profile and good efficacy, though relapse rates are high. Systemic glucocorticoids should be reserved to patients unable to take budesonide. In glucocorticoid refractory disease, medications that have been tried include cholestyramine, bismuth salicylate, antibiotics, probiotics, aminosalicylates, immunomodulators, and anti-tumor necrosis factor-alpha inhibitors. More research is needed for the creation of a systematic stepwise approach for relapsing and refractory disease.

Proton pump inhibitor use is associated with elevated faecal calprotectin levels. A cross-sectional study on subjects referred for colonoscopy

OBJECTIVES

Faecal Calprotectin (FC) is a sensitive marker for gut inflammation. However, slightly elevated FC levels are also common in subjects without inflammation. We investigated the association between FC and clinical factors including concomitant use of medical therapy in patients with a normal colonoscopy.

MATERIAL AND METHODS

Out-patients (n = 1263) referred for colonoscopy, performed FC test (CALPRO) the day before the start of bowel preparation. All subjects answered questionnaires that included questions on the present and past health history, concomitant medical treatment and gastrointestinal symptoms (GSRS). A medical record chart review was performed to check for concomitant disease, cause of referral and the result of the colonoscopy including biopsies. Inclusion criteria were a normal colonoscopy. Exclusion criteria were inflammatory bowel disease, colon cancer and high-grade dysplasia.

RESULTS

Five hundred ninety subjects fulfilled the inclusion criteria and completed the study. Thirty-six per cent of the subjects had a FC >50 µg/g. In a logistic regression analysis, age (adjusted OR: 1.051; CI: 1.032-1.071), and the use of proton pump inhibitors (adjusted OR: 3.843; CI: 2.338-6.316), non-steroid anti-inflammatory drugs (adjusted OR: 2.411; CI: 1.162-5.002) and acetylsalicylic acid (adjusted OR: 2.934; CI: 1.085-3.448) were significantly associated with an elevated FC (>50 µg/g).

CONCLUSIONS

More than one-third of the patients with a normal colonoscopy performed in clinical routine had a slightly elevated FC level. Our results emphasise the need for attention to age, the use of proton pump inhibitors, non-steroid anti-inflammatory drugs and acetylsalicylic acid in the interpretation of FC tests in clinical practice.

Validating microscopic colitis (MC) in Swedish pathology registers

OBJECTIVE

Microscopic colitis (MC), encompassing collagenous colitis (CC) and lymphocytic colitis (LC), is a diagnosis which relies on histopathologic criteria. This report examines the validity of having a diagnosis of MC in Swedish pathology registers.

METHODS

We reviewed patient charts from 215 randomly selected individuals from 15 pathology departments in five healthcare regions in Sweden with a relevant histopathology code for MC on colon biopsies. Information on clinical symptoms and laboratory data were obtained from medical chart review. We obtained sufficient data on 211 individuals for calculating positive predictive values (PPVs) for MC.

RESULTS

In total, 200/211 patients with a histopathology diagnosis of MC were confirmed as also having a clinical diagnosis of MC after chart review, yielding a PPV of 95% (95%CI =91-97%). The PPV for CC was 95% (95%CI =87-98%) and 85% for LC (95%CI =78-90%). The median age at biopsy was 67 years (range 17-90 years), and 72% (n = 154) were women. The most common symptoms in patients with MC histopathology were diarrhea (96% of patients), weight loss (24%) and abdominal pain (13%). Four percent (4/111) of patients with available data on stool culture were positive for gastrointestinal pathogens (none had Clostridium difficile). In 81 patients with available celiac serology, five (6%) were positive. Twenty-six percent of all patients had at least one other autoimmune disease, the most frequent being hypothyroidism (8%) and celiac disease (6%).

CONCLUSIONS

This study found a high validity for MC as recorded in Swedish pathology registers.

The Vampire Study: Significant elevation of faecal calprotectin in healthy volunteers after 300 ml blood ingestion mimicking upper gastrointestinal bleeding

Background

Faecal calprotectin correlates with histological and clinical activity in inflammatory bowel disease. Gastrointestinal bleeding might also increase faecal calprotectin levels, erroneously implying intestinal inflammation; however, this possibility has not been systematically assessed.

Methods

Sixteen healthy volunteers without gastrointestinal disease and normal faecal calprotectin baseline values ingested their own blood twice, either by drinking or via nasogastric tube. Quantities of 100 ml and 300 ml blood were ingested in a randomised order, with a 28-day wash-out period. Faecal calprotectin, faecal occult blood test, and the occurrence of melaena were assessed. Faecal calprotectin ≥ 50 µg/g was considered elevated.

Results

Melaena was reported by all healthy volunteers after 300 ml and by 11/15 healthy volunteers (71%) after 100 ml blood ingestion. One day after ingestion of 300 ml blood, 8/16 faecal calprotectin tests were positive compared to 1/16 at baseline (p = 0.016). Faecal calprotectin levels above > 200 µg/g were rarely observed. There was a trend for faecal calprotectin test positivity also after ingestion of 100 ml.

Conclusion

Ingestion of blood resulted in an increase in faecal calprotectin-positive tests. Gastrointestinal bleeding should be considered as a potential cause of mild faecal calprotectin elevation > 50 µg/g; however, increased faecal calprotectin above > 250-300 µg/g, the established cut-off for relevant intestinal inflammation in patients with inflammatory bowel disease, is rare.

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

BACKGROUND

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

SUMMARY

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

Analysis of short-chain fatty acids in human feces: A scoping review

Short-chain fatty acids (SCFAs) play a crucial role in maintaining homeostasis in humans, therefore the importance of a good and reliable SCFAs analytical detection has raised a lot in the past few years. The aim of this scoping review is to show the trends in the development of different methods of SCFAs analysis in feces, based on the literature published in the last eleven years in all major indexing databases. The search criteria included analytical quantification techniques of SCFAs in different human clinical and in vivo studies. SCFAs analysis is still predominantly performed using gas chromatography (GC), followed by high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and capillary electrophoresis (CE). Performances, drawbacks and advantages of these methods are discussed, especially in the light of choosing a proper pretreatment, as feces is a complex biological material. Further optimization to develop a simple, cost effective and robust method for routine use is needed.

Optimization of a Scoring System to Predict Microscopic Colitis in a Cohort of Patients With Chronic Diarrhea

GOALS

Our aim was to develop a scoring system to predict risk of microscopic colitis (MC), to identify patients at low risk, potentially avoiding unnecessary biopsies.

BACKGROUND

Patients with chronic diarrhea often undergo colonoscopy with biopsy, but few have histologic abnormalities.

STUDY

We conducted a retrospective study of patients with chronic diarrhea and a macroscopically normal colonoscopy at our institution over a 9-month period. Multivariable logistic regression assessed the association between predictors and the presence of biopsy-proven MC.

RESULTS

The derivation cohort included 617 patients. Median age was 55.1 (39.6 to 68.1) years; 397 (64.3%) were female and 81 (13.1%) had MC. Age ≥55 years, duration of diarrhea ≤6 months, ≥5 bowel movements per day, body mass index <30 kg/m, current smoking, and current use of selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitorss and non-steroidal anti-inflammatory drugs were independently associated with MC. A score of ≥10 points in our scoring system, yielded an area under the ROC curve (AUC) of 0.83 with a sensitivity of 93% and specificity of 49% in predicting which patients have MC. The negative predictive value (NPV) was 97.8% (95.0% to 99.1%).In the validation cohort, the scoring system performed similarly (AUC 0.79, sensitivity 91%, specificity 49%, NPV 97%). By avoiding biopsies in patients at low risk of having MC, costs associated with colon biopsies could be reduced by almost 43%.

CONCLUSION

This scoring system including 7 clinical variables was able to identify patients unlikely to have MC, with excellent sensitivity, reasonable specificity, and a high NPV, translating into important potential cost savings.

Biomarkers and Microscopic Colitis: An Unmet Need in Clinical Practice

One of the most common causes of chronic diarrhea is ascribed to microscopic colitis (MC). MC is classified in subtypes: collagenous colitis (CC) and lymphocytic colitis (LC). Patients with MC report watery, non-bloody diarrhea of chronic course, abdominal pain, weight loss, and fatigue that may impair patient's health-related quality of life. A greater awareness, and concomitantly an increasing number of diagnoses over the last years, has demonstrated that the incidence and prevalence of MC are on the rise. To date, colonoscopy with histological analysis on multiple biopsies collected along the colon represents the unique accepted procedure used to assess the diagnosis of active MC and to evaluate the response to medical therapy. Therefore, the emerging need for less-invasive procedures that are also rapid, convenient, standardized, and reproducible, has encouraged scientists to turn their attention to the identification of inflammatory markers and other molecules in blood or feces and within the colonic tissue that can confirm a MC diagnosis. This review gives an update on the biomarkers that are potentially available for the identification of inflammatory activity, related to CC and LC.

Microscopic colitis: A literature review

Microscopic colitis (MC) refers to chronic inflammation of the colon which is characterized by histologic changes at the level of a radiologically and endoscopically normal mucosa. It is a common cause of chronic non-bloody diarrhea that occurs primarily in older individuals; however, there are few studies in the literature with strong scientific evidence compared to other inflammatory bowel diseases (IBD), which limits the knowledge of physicians and pathologists. This article aims to review the information on MC, describing diagnostic methods and drugs available for treatment. We conducted a search of the Pubmed database and CAPES Portal using the keywords "microscopic colitis", "collagenous colitis", "lymphocytic colitis", and "review" for selection of articles published between 1996 and 2015 related to the topic. Based on the studies discussed in this review, we conclude that MC is a relatively new gastrointestinal disorder, most studies are incipient particularly with respect to pathophysiology and immunology, and budesonide is the best documented short-term treatment. However, further studies are needed to elucidate the best strategy for treatment in the long term.

Fecal calprotectin: a marker for clinical differentiation of microscopic colitis and irritable bowel syndrome

Background

The aim of this study is to compare two methods for measuring fecal calprotectin (FC) concentration and to evaluate the possibility of differentiation between microscopic colitis (MC) and irritable bowel syndrome (IBS).

Methods

Twenty-three patients with MC (six patients with active disease and 17 patients retested in remission) and 20 patients with IBS were prospectively included in this study. Active disease state of MC was determined by clinical symptoms of >3 bowel movements per day and histological correlate. All patients underwent ileocolonoscopy, including segmental biopsy samples for histology. FC levels in stool samples were analyzed using a rapid test system (Quantum Blue^®) and an enzyme-linked immunosorbent assay (ELISA).

Results

FC levels were significantly higher in patients with active MC (median 48 μg/g [23–106]) compared to patients with IBS (median 2 μg/g [1–111.83]), P=0.0001 using an ELISA. FC level of patients with MC in remission was 22 μg/g (1–106.4), which is similar to those identified in patients with IBS. The difference of FC levels between active MC and IBS was not detected by the FC rapid test (P=0.635).

Discussion

FC levels might serve as parameter for differentiation between patients with active MC and IBS. Since there is no surrogate marker available at present for MC, FC appears to be a candidate for differentiating MC from IBS.

Conclusion

High FC levels, which were analyzed by ELISA, are a potential marker for patients with active MC compared to those with IBS. The FC rapid test was less suitable for this purpose.

Advances for improved diagnosis of microscopic colitis in patients with chronic diarrhoea

Microscopic colitis is a generic term that includes 2 main forms, collagenous colitis and lymphocytic colitis, and describes a form of inflammatory bowel disease with a chronic and relapsing course. The incidence of microscopic colitis is between 2 and 8 times higher in women than in men, although age, more than sex, increases the risk of collagenous colitis (odds ratio [OR] 8.3 for age ≥65 vs. <65 and OR 2.8 for women). The main symptom is chronic non-bloody watery diarrhoea. Other common symptoms include abdominal pain (50%-70%), with the result that many patients with microscopic colitis meet criteria for irritable bowel syndrome. Colonoscopy with multiple colonic biopsies is currently recommended, as histological changes are the main characteristic feature. The colonic mucosa is macroscopically normal, although certain minimal endoscopic abnormalities have been described.

Optimal management of collagenous colitis: a review

Collagenous colitis (CC) is an increasingly recognized cause of chronic inflammatory bowel disease characterized by watery non-bloody diarrhea. As a lesser studied inflammatory bowel disease, many aspects of the CC's natural history are poorly understood. This review discusses strategies to optimally manage CC. The goal of therapy is to induce clinical remission, <3 stools a day or <1 watery stool a day with subsequent improved quality of life (QOL). Antidiarrheal can be used as monotherapy or with other medications to control diarrhea. Budesonide therapy has revolutionized treatment and is superior to prednisone, however, the treatment is associated with high-relapse rates and the management of refractory disease is challenging. Ongoing trials will address the safety and efficacy of low-dose maintenance therapy. For those with refractory disease, case reports and case series support the role of biologic agents. Diversion of the fecal stream normalizes colonic mucosal changes and ileostomy may be considered where anti-tumor necrosis factor (TNF)-α agents are contraindicated. Underlying celiac disease, bile salt diarrhea, and associated thyroid dysfunction should be ruled out. The author recommends smoking cessation as well as avoidance of nonsteroidal anti-inflammatories as well as other associated medications.

Current concepts on microscopic colitis: evidence-based statements and recommendations of the Spanish Microscopic Colitis Group

BACKGROUND

Microscopic colitis (MC) is an underdiagnosed inflammatory bowel disease.

AIM

To develop an evidence-based clinical practice guide on MC current concepts.

METHODS

Literature search was done on the Cochrane Library, EMBASE and MEDLINE electronic databases, which were consulted covering the period up until March 2015. Work groups were selected for each of the reviewed topics, with the purpose of drafting the initial statements and recommendations. They subsequently underwent a voting process based on the Delphi method. Each statement/recommendation was accompanied by the result of the vote the level of evidence, and discussion of the corresponding evidence. The grade of recommendation (GR) using the GRADE approach was established for diagnosis and treatment recommendations.

RESULTS

Some key statements and recommendations are: advancing age increases the risk of developing MC, mainly in females. The symptoms of MC and IBS-D may be similar. If MC is suspected, colonoscopy taking biopsies is mandatory. Treatment with oral budesonide is recommended to induce clinical remission in patients with MC. Oral mesalazine is not recommended in patients with collagenous colitis for the induction of clinical remission. The use of anti-TNF-alpha drugs (infliximab, adalimumab) is recommended for the induction of remission in severe cases of MC that fail to respond to corticosteroids or immunomodulators, as an alternative to colectomy.

CONCLUSIONS

This is the first consensus paper on MC based on GRADE methodology. This initiative may help physicians involved in care of these patients in taking decisions based on evidence.

Contemporary methods for the diagnosis and treatment of microscopic colitis

Microscopic colitis is a common cause of chronic diarrhea. It is characterized by non-bloody watery diarrhea with macroscopically normal colonic mucosa. Its specific histological characteristics confirm the diagnosis. Two distinct histological forms can be identified, namely, collagenous colitis and lymphocytic colitis. In collagenous colitis, a thick colonic subepithelial collagenous deposit can be observed, whereas in lymphocytic colitis, a pronounced intraepithelial lymphocytic inflammation in the absence of a thickened collagen band can be identified. Microscopic colitis occurs more frequently in elderly females and its etiology is believed to be multifactorial, although smoking and consumption of several drugs have been identified as risks factors for the development of the disease. The treatment is based on avoiding the risks factors and administration of oral budesonide.

Fecal Calprotectin and serum chromogranin A as potential biomarkers of irritable bowel syndrome symptom severity

Irritable bowel syndrome (IBS) is a disorder of the lower gastrointestinal (GI) tract, which manifests as abdominal pain and/or discomfort accompanied by altered bowel function, in the absence of structural pathology. The onset and precipitation of IBS is the result of an interaction among several factors, including psychological distress, altered GI sensation and processing of sensory information as well as GI inflammation. These factors have varying contributions to disorder etiology in different patients, and in line with that, there is now emerging evidence about a low-grade inflammation in a subgroup of IBS patients. Because IBS diagnosis is based on the ROME III criteria, with the exclusion of structural pathology, patients are often exposed to numerous invasive and unpleasant tests. In order to decrease the cost of repeated testing, while simultaneously alleviating patients' anxiety, research should be aimed at detecting cost-effective biomarkers. We hypothesize chromogranin A (CgA) and fecal Calprotectin (FC) could be used to eliminate possible organic causes of IBS symptoms. Also, we hypothesize FC could be helpful in detecting IBS patients with low-grade inflammation. Forty-eight outpatients with IBS (76% females) completed a set of psychosocial measures (HRQoL, STAI, BDI, VSI, SF-36), and their FC and CgA levels were obtained. We found elevated CgA levels in 4 patients, but CgA levels were not related to any of the psychological measures used. Elevated FC levels were found in 12 patients. FC levels significantly correlated with the physical component of health related quality of life (HRQoL) (r48=-.42, p<.01). In addition, one-way ANOVA's were performed to test possible differences in psychosocial measures depending on the patient's FC status. The analysis showed only one significant difference. Patients with the highest levels of FC had significantly lower physical component of HRQoL compared to the other two groups of patients.

Microscopic colitis

Microscopic colitis (MC) is the common denominator for lymphocytic and collagenous colitis (CC). It is now recognized as a relatively frequent cause of diarrhea that equals the prevalence of inflammatory bowel disease. Patients are typically middle-aged women, but disease may occur at every age. Patients with MC report watery, non-bloody diarrhea in the absence of endoscopic and radiologic abnormalities. Lymphocytic colitis is characterized by an increased number of intraepithelial lymphocytes, and CC by a thickened subepithelial collagen band, whereas in both an increased mononuclear infiltration of the lamina propria is found. The pathogenesis of MC is largely unknown, but may relate to autoimmunity, adverse reactions to drugs or (bacterial) toxins, and abnormal collagen metabolism in the case of CC. Budesonide is so far the only drug that has proven efficacy in randomized controlled trials both for the induction and maintenance of remission. Patients who are nonresponsive, dependent or who experience side effects on budesonide may benefit from thiopurine or anti-TNF treatment, but these options are still experimental. The long-term prognosis of MC is good; it does not appear to predispose to malignancies and can in some cases be self-limiting. Further research and randomized clinical trials are required to expand our understanding of the natural course and the pathogenesis of MC.

Fecal calprotectin use in inflammatory bowel disease and beyond: A mini-review

Given the number of inflammatory disorders affecting the gastrointestinal tract directly and indirectly, coupled with the considerable overlap with functional disorders, it is evident that more useful noninvasive diagnostic tests are required to aid with diagnosis. If these tests can also have some utility for individual patient follow-up in terms of disease activity and response to treatment, as well as providing forewarning of disease relapse, it would be extremely useful information for the clinician. One recently described test that may fulfill several of these attributes is based on leakage of a mononuclear cell cytoplasmic protein, calprotectin, along the intestinal tract, which can then be quantified in feces. This has been used to distinguish patients exhibiting symptoms of irritable bowel syndrome from patients with inflammatory bowel disease, with a measure of success greater than with currently used techniques. The present article summarizes the experience with this test used in inflammatory bowel disease, as well as a variety of gastrointestinal disorders.

Faecal calprotectin for differentiating between irritable bowel syndrome and inflammatory bowel disease: a useful screen in daily gastroenterology practice

OBJECTIVE

To determine the best faecal calprotectin (FCP) cut-off level for differentiating between irritable bowel syndrome (IBS) and organic disease, particularly inflammatory bowel disease (IBD), in patients presenting with chronic diarrhoea.

DESIGN

Retrospective analysis of patients who had colonoscopy, histology and FCP completed within 2 months.

SETTING

District general hospital.

PATIENTS

Consecutive new patients with chronic diarrhoea lasting longer than 4 weeks.

INTERVENTIONS

Patients were seen by a single experienced gastroenterologist and listed for colonoscopy with histology. Laboratory investigations included a single faecal specimen for calprotectin assay (lower limit of detection: 8 µg/g), the results used for information only.

MAIN OUTCOME MEASURES

Six FCP cut-off levels (range 8-150 µg/g) were compared against the 'gold standard' of histology: inflammation 'present' or 'absent'.

RESULTS

Of 119 patients studied, 98 had normal colonoscopy and histology. The sensitivity of FCP to detect IBD at cut-off levels 8, 25 and 50 µg/g was 100% (with corresponding specificity 51%, 51%, 60%). In contrast, the lowest FCP cut-off, 8 µg/g, had 100% sensitivity to detect colonic inflammation, irrespective of cause (with negative predictive value (NPV) 100%). Importantly, 50/119 patients (42%) with FCP <8 µg/g had normal colonoscopy and histology.

CONCLUSIONS

Our results suggest that using FCP to screen patients newly referred for chronic diarrhoea could exclude all without IBD and, at a lower cut-off, all without colonic inflammation, thus avoiding the need for colonoscopy. Such a major reduction has implications for resource allocation.

Fecal calprotectin is an effective diagnostic tool that differentiates inflammatory from functional intestinal disorders

BACKGROUND

The clinical pictures of functional gastrointestinal disorders and inflammatory diseases can be quite similar leading to inappropriate and expensive investigations. Objective. To investigate fecal calprotectin (FC) diagnostic performance in different gastrointestinal conditions.

MATERIAL AND METHODS

Stool specimens of 66 outpatients referred for colonoscopy were collected for further FC determination. Diagnostic accuracy was assessed by the area under the curve (AUC). Sensitivity (Se), specificity (Sp), positive (PPV), and negative predictive values (NPV) were calculated according to the presence of inflammation and the main final diagnosis.

RESULTS

Histological inflammation was found in 45 (68%) patients: 24 had a diagnosis of inflammatory bowel disease (IBD) while 21 reported miscellaneous conditions (5 microscopic colitis, 2 eosinophilic colitis, and 14 nonspecific chronic colitis). The diagnosis in the 21 (32%) patients without inflammation was irritable bowel syndrome (IBS). Median FC values were 268 µg/g (95% CI, 151-343) and 49 µg/g (95% CI, 23-101) in patients with and without inflammation, respectively (p = 0.0001). AUC value of FC was 0.811 (Se = 68.9%, Sp = 71.4%, PPV = 83.8%, and NPV = 56.3% with a cutoff value of 100 µg/g) for discriminating between patients with and without inflammation and 0.931 (Se = 87.5%, Sp = 90.5%, PPV = 91.3%, and NPV = 86.4% with a cutoff value of 150 µg/g) for discriminating between patients with IBS and IBD. Using the cutoff value recommended by the manufacturer (50 µg/g), we found Se =100%, Sp =52.4%, PPV =70.6%, and NPV =100% for the diagnosis of IBD.

CONCLUSIONS

FC appears to be a reliable noninvasive biomarker of intestinal inflammation useful to improve the appropriateness of colonoscopy requests.

Diagnosis and management of microscopic colitis: current perspectives

Collagenous colitis and lymphocytic colitis, together constituting microscopic colitis, are common causes of chronic diarrhea. They are characterized clinically by chronic nonbloody diarrhea and a macroscopically normal colonic mucosa where characteristic histopathological findings are seen. Previously considered rare, they now have emerged as common disorders that need to be considered in the investigation of the patient with chronic diarrhea. The annual incidence of each disorder is five to ten per 100,000 inhabitants, with a peak incidence in 60- to 70-year-old individuals and a predominance of female patients in collagenous colitis. The etiology and pathophysiology are not well understood, and the current view suggests an uncontrolled mucosal immune reaction to various luminal agents in predisposed individuals. Clinical symptoms comprise chronic diarrhea, abdominal pain, fatigue, weight loss, and fecal incontinence that may impair the patient's health-related quality of life. An association is reported with other autoimmune disorders, such as celiac disease, thyroid disorders, diabetes mellitus, and arthritis. The best-documented treatment, both short-term and long-term, is budesonide, which induces clinical remission in up to 80% of patients after 8 weeks' treatment. However, after successful budesonide therapy is ended, recurrence of clinical symptoms is common, and the best possible long-term management deserves further study. The long-term prognosis is good, and the risk of complications, including colonic cancer, is low. We present an update of the epidemiology, pathogenesis, diagnosis, and management of microscopic colitis.

Chronic non-bloody diarrhoea: a prospective study in Malmö, Sweden, with focus on microscopic colitis

BACKGROUND

Chronic non-bloody diarrhoea affects up to 5% of the population. Microscopic colitis is one of the most common causes, encompassing the subtypes collagenous colitis and lymphocytic colitis. The diagnosis of microscopic colitis is made by histological examination of colonic mucosal biopsy specimens. The aim of this investigation was to determine whether laboratory parameters or questions about disease history or concomitant disease could be helpful in discriminating patients with MC from those with a histologically normal colonic mucosa.

FINDINGS

Patients admitted for colonoscopy because of chronic non-bloody diarrhoea (>2 loose stools for >3 weeks) at endoscopy units in Malmö during 2007 and 2009, were enrolled. A total number of 78 patients were included (60 women, 18 men, median age 59, IQR 45-69 years). Out of these 78, 15 patients (19%) had microscopic colitis (CC; n = 10, LC; n = 5). MC was especially prevalent in patients above the age of 50 (25%). No differences were found between those with normal histology and MC in laboratory analyses (inflammatory and liver parameters). Neither were differences shown in questions regarding symptoms, environmental factors or concomitant diseases except for an association with celiac disease (p = 0.019) and a trend maybe indicating an inverse association with appendectomy (p = 0.057).

CONCLUSIONS

Microscopic colitis is associated with female gender, celiac disease and consumption of NSAIDs. Trends were observed indicating that age above 50 years, acute onset and absence of appendectomy may be associated with MC. No associations were observed with other symptoms, calprotectin levels or liver parameters.

Clinical utility of fecal biomarkers for the diagnosis and management of inflammatory bowel disease

Diagnosis and monitoring of inflammatory bowel diseases rely on clinical, endoscopic, and radiologic parameters. Inflammatory biomarkers have been investigated as a surrogate marker for endoscopic diagnosis of inflammatory activity. Fecal inflammatory biomarkers such as calprotectin and lactoferrin are direct products of bowel inflammation and provide an accurate and noninvasive diagnostic and monitoring modality for Crohn's disease and ulcerative colitis. This report contains an overview of the currently existing literature pertaining to clinical implications of fecal biomarkers for diagnosis, monitoring, and prediction of outcomes of inflammatory bowel disease.

The use of fecal calprotectin as a biomarker in gastrointestinal disease

Abdominal discomfort including pain, bloating and diarrhea is common. It often arises from functional gastrointestinal disorders but may indicate inflammatory bowel disease (IBD). Calprotectin is an abundant neutrophil protein that is released during inflammation. When measured in feces, it can be used to differentiate between non-organic and inflammatory intestinal disorders, especially to identify IBD. Fecal calprotectin might also be useful to monitor patients with IBD under treatment and to predict the risk of recurrence of active disease prior to clinical relapse. The use of fecal calprotectin has been investigated in a number of gastrointestinal disorders other than IBD, for example, as screening test for colorectal cancer but the available data are limited. This article summarizes the current literature on the use of fecal calprotectin in clinical practice.

Diagnostics and prognostics of inflammatory bowel disease with fecal neutrophil-derived biomarkers calprotectin and lactoferrin

Crohn's disease (CD), ulcerative colitis (UC), and colitis unclassified, collectively defined as inflammatory bowel disease (IBD), are the consequence of chronic inflammatory reactions in the gastrointestinal tissue. Endoscopy with biopsies is the mainstay in the diagnosis of this inflammation and is also important in the assessment of disease activity and monitoring of treatment. Furthermore, mucosal healing is increasingly becoming a therapeutic target for treatment of IBD and the golden standard of assessing it is endoscopy. However, due to the costs, invasiveness, and to limited endoscopic capacity, the need is strong for reliable surrogate markers of intestinal inflammation. Bowel contents, being in close contact with intestinal mucosa, can take up molecules that are measurable from stool samples and thus can serve as markers of inflammation. The fecal neutrophil-derived biomarkers, especially calprotectin and lactoferrin, have several features of an ideal test for detecting intestinal inflammation: they are noninvasive, simple, and low in cost. The utility of these biomarkers in distinguishing IBD from noninflammatory conditions such as irritable bowel syndrome is well documented. They correlate closely with endoscopic activity both in CD and UC. They allow serial monitoring of disease activity and of treatment success, and can even serve in predicting clinical relapse in unsymptomatic patients or sustained remission after induction with TNF-α-blocking agents. In this review an overview will be given to the role of fecal neutrophil-derived biomarkers calprotectin and lactoferrin in diagnostics and prognostics of IBD.

Monoclonal antibody testing for fecal calprotectin is superior to polyclonal testing of fecal calprotectin and lactoferrin to identify organic intestinal disease in patients with abdominal discomfort

BACKGROUND AND AIMS

Fecal calprotectin and lactoferrin are sensitive markers of mucosal inflammation. We compared three different assays in their ability to identify patients with organic intestinal disease.

METHODS

In a post-hoc analysis of a prospective study, we examined 405 unselected patients with abdominal complaints referred for endoscopy to the University Hospital Basel, Switzerland. Calprotectin (EK-CAL, Bühlmann Laboratories, Switzerland; PhiCal, Calpro AS, Norway) and lactoferrin (IBD-Scan, Techlab, USA) were measured using enzyme-linked immunosorbent assays. The presence of a clinically significant endoscopic finding was the primary endpoint of the study. Final diagnoses were adjudicated blinded to calprotectin values.

RESULTS

The prevalence of organic intestinal disease was 35.3%. Receiver operating characteristics analysis calculated an area under the curve (AUC) for EK-CAL of 0.918, which was significantly better than for PhiCal (AUC 0.842, P<0.001) and IBD-Scan (AUC 0.830, P=0.003) to identify patients with organic intestinal disease. Overall test accuracy was 88.1% for EK-CAL, 83.7% for PhiCal, and 81.3% for IBD-Scan. Optimal cut-off value calculated for PhiCal and IBD-Scan were lower than recommended by the manufacturer.

CONCLUSIONS

Monoclonal testing of calprotectin is superior to both polyclonal calprotectin testing and fecal lactoferrin in identifying symptomatic patients with organic intestinal disease.

Microscopic colitis: Current status, present and future challenges: statements of the European Microscopic Colitis Group

Microscopic colitis (MC) is an inflammatory bowel disease presenting with chronic, non-bloody watery diarrhoea and few or no endoscopic abnormalities. The histological examination reveals mainly two subtypes of MC, lymphocytic or collagenous colitis. Despite the fact that the incidence in MC has been rising over the last decades, research has been sparse and our knowledge about MC remains limited. Specialists in the field have initiated the European Microscopic Colitis Group (EMCG) with the primary goal to create awareness on MC. The EMCG is furthermore a forum with the intention to promote clinical and basic research. In this article statements and comments are given that all members of the EMCG have considered being of importance for a better understanding of MC. The paper focuses on the newest updates in epidemiology, symptoms and diagnostic criteria, pathophysiology and highlights some unsolved problems. Moreover, a new treatment algorithm is proposed on the basis of new evidence from well-designed, randomized control trials.

Fecal calprotectin in clinical practice: a noninvasive screening tool for patients with chronic diarrhea

BACKGROUND

Surrogate markers of colorectal inflammation are increasingly being recognized as important in differentiating organic from functional intestinal disorders. Fecal calprotectin (FC) can be easily measured in the stool, being released by leukocytes in inflammatory conditions.

AIM

We evaluated FC as an index of inflammation in consecutive outpatients referred for colonoscopy for chronic, nonbloody diarrhea.

METHODS

Stool specimens of 346 outpatients with chronic, nonbloody diarrhea, referred for colonoscopy, were measured for FC levels. The proportion of patients correctly diagnosed with the test and the relationship with endoscopic and histologic findings were measured.

RESULTS

Abnormal endoscopic findings were detected in 104 patients (30.1%). Histologic findings included 142 patients (41.0%) with inflammation and 204 (59.0%) without inflammation. Fecal excretion of calprotectin significantly correlated with the finding of inflammation at endoscopy and histology (P<0.0001). When 150 mcg/g of stool was used as the upper reference limit, FC showed 75.4% sensitivity and 88.3% specificity, with 81.7% positive and 83.7% negative predictive values for histologic inflammation.

CONCLUSIONS

In outpatients referred for colonoscopy a measurement of FC is accurate to identify those with histologic inflammation. Assay of FC may be a reliable and noninvasive screening tool to identify inflammatory causes of chronic, nonbloody diarrhea.