Accuracy of a no-biopsy approach for the diagnosis of coeliac disease across different adult cohorts.

OBJECTIVE: We aimed to determine the predictive capacity and diagnostic yield of a 10-fold increase in serum IgA antitissue transglutaminase (tTG) antibody levels for detecting small intestinal injury diagnostic of coeliac disease (CD) in adult patients. DESIGN: The study comprised three adult cohorts. Cohort 1: 740 patients assessed in the specialist CD clinic at a UK centre; cohort 2: 532 patients with low suspicion for CD referred for upper GI endoscopy at a UK centre; cohort 3: 145 patients with raised tTG titres from multiple international sites. Marsh 3 histology was used as a reference standard against which we determined the performance characteristics of an IgA tTG titre of ≥10×ULN for a diagnosis of CD. RESULTS: Cohort 1: the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 54.0%, 90.0%, 98.7% and 12.5%, respectively. Cohort 2: the sensitivity, specificity, PPV and NPV for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 50.0%, 100.0%, 100.0% and 98.3%, respectively. Cohort 3: the sensitivity, specificity, PPV and NPV for IgA tTG levels of ≥10×ULN at identifying individuals with Marsh 3 lesions were 30.0%, 83.0%, 95.2% and 9.5%, respectively. CONCLUSION: Our results show that IgA tTG titres of ≥10×ULN have a strong predictive value at identifying adults with intestinal changes diagnostic of CD. This study supports the use of a no-biopsy approach for the diagnosis of adult CD.

The correlation between vitamin D levels and demographics in patients with gastrointestinal disorders; a cross-sectional study.

AIM: The aim of the present study was to evaluate vitamin D levels, in correlation with age, body mass index (BMI), gender and ethnicity, in patients with gastrointestinal disorders (GID). BACKGROUND: Vitamin D deficiency (VDD) is a global health issue, affecting over 1 billion people. A great body of evidence has shown that it can lead to increased morbidity and mortality. Furthermore, latitude, sedentary lifestyle, limited sunlight exposure, ageing and the presence of comorbidities and chronic illnesses, places patients at an increased risk of VDD. METHODS: 305 consecutive patients, with GID, were assessed for vitamin D levels, using a two-step competitive binding immunoenzymatic assay. Patients were then classified as adequate (50-150nmol/l), insufficient (25-50nmol/l) and deficient (<25nmol/l). RESULTS: 62% of the investigated subjects had low vitamin D levels. From this group, 132 patients (43.3%) had insufficient vitamin D levels, 57 (18.7%) had deficient levels and 116 (38%) had adequate levels. Age was not significantly different in the 3 groups (p=0.29). Interestingly, vitamin D levels were significantly lower in men (39.23±23.62) compared to women (50.68±24.46) (p=0.0001). The BMI was significantly higher in patients with insufficient vitamin D levels. Being of Asian ethnicity had a positive influence on vitamin D levels (B=0.076) (p<0.0001). 71.4% of patients, with IBD, and 60% of patients, with abnormal liver function, had low vitamin D levels. CONCLUSION: VDD has a high prevalence in patients with GID in particular IBD and liver disease in the United Kingdom. Routine vitamin D testing and supplementations in the case of deficiency and suboptimal level of vitamin D for patients with hepatobiliary, pancreatic, kidney, malabsorptive and restrictive diseases/surgeries is recommended.

ROC-king onwards: intraepithelial lymphocyte counts, distribution & role in coeliac disease mucosal interpretation.

OBJECTIVES: Counting intraepithelial lymphocytes (IEL) is central to the histological diagnosis of coeliac disease (CD), but no definitive 'normal' IEL range has ever been published. In this multicentre study, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off between normal and CD (Marsh III lesion) duodenal mucosa, based on IEL counts on >400 mucosal biopsy specimens. DESIGN: The study was designed at the International Meeting on Digestive Pathology, Bucharest 2015. Investigators from 19 centres, eight countries of three continents, recruited 198 patients with Marsh III histology and 203 controls and used one agreed protocol to count IEL/100 enterocytes in well-oriented duodenal biopsies. Demographic and serological data were also collected. RESULTS: The mean ages of CD and control groups were 45.5 (neonate to 82) and 38.3 (2-88) years. Mean IEL count was 54±18/100 enterocytes in CD and 13±8 in normal controls (p=0.0001). ROC analysis indicated an optimal cut-off point of 25 IEL/100 enterocytes, with 99% sensitivity, 92% specificity and 99.5% area under the curve. Other cut-offs between 20 and 40 IEL were less discriminatory. Additionally, there was a sufficiently high number of biopsies to explore IEL counts across the subclassification of the Marsh III lesion. CONCLUSION: Our ROC curve analyses demonstrate that for Marsh III lesions, a cut-off of 25 IEL/100 enterocytes optimises discrimination between normal control and CD biopsies. No differences in IEL counts were found between Marsh III a, b and c lesions. There was an indication of a continuously graded dose-response by IEL to environmental (gluten) antigenic influence.

Gluten-Free Diet Indications, Safety, Quality, Labels, and Challenges.

A gluten-free diet (GFD) is the safest treatment modality in patient with coeliac disease (CD) and other gluten-related disorders. Contamination and diet compliance are important factors behind persistent symptoms in patients with gluten related-disorders, in particular CD. How much gluten can be tolerated, how safe are the current gluten-free (GF) products, what are the benefits and side effects of GFD? Recent studies published in Nutrients on gluten-free products' quality, availability, safety, as well as challenges related to a GFD are discussed.

Microscopic enteritis: Bucharest consensus.

Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy.

Using bacterial biomarkers to identify early indicators of cystic fibrosis pulmonary exacerbation onset.

Acute periods of pulmonary exacerbation are the single most important cause of morbidity in cystic fibrosis patients, and may be associated with a loss of lung function. Intervening prior to the onset of a substantially increased inflammatory response may limit the associated damage to the airways. While a number of biomarker assays based on inflammatory markers have been developed, providing useful and important measures of disease during these periods, such factors are typically only elevated once the process of exacerbation has been initiated. Identifying biomarkers that can predict the onset of pulmonary exacerbation at an early stage would provide an opportunity to intervene before the establishment of a substantial immune response, with major implications for the advancement of cystic fibrosis care. The precise triggers of pulmonary exacerbation remain to be determined; however, the majority of models relate to the activity of microbes present in the patient's lower airways of cystic fibrosis. Advances in diagnostic microbiology now allow for the examination of these complex systems at a level likely to identify factors on which biomarker assays can be based. In this article, we discuss key considerations in the design and testing of assays that could predict pulmonary exacerbations.

Bacterial community diversity in cultures derived from healthy and inflamed ileal pouches after restorative proctocolectomy.

BACKGROUND: Pouchitis is believed to occur as a reaction to dysbiosis. In this study we assessed differences between mucosal bacterial communities cultured from noninflamed and inflamed ileal pouches. METHODS: Thirty-two ileal pouch patients, 22 with ulcerative colitis (UC) and 10 with familial adenomatous polyposis (FAP), underwent symptomatic, endoscopic, and histological assessment. The Objective Pouchitis Score (OPS) and the Pouch Disease Activity Index (PDAI) were used to diagnose pouchitis. Seven UC patients had pouchitis (UC+), 15 had a noninflamed pouch (UC-), 9 had a noninflamed pouch (FAP-), and 1 FAP patient had pouchitis (FAP+). Biopsies taken from the ileal mucosa of the pouch were cultured under aerobic and anaerobic conditions. Following standardized DNA extraction a polymerase chain reaction (PCR) was performed to generate 16S rRNA gene products. A "fingerprint" of the bacterial community within each sample was created using terminal-restriction fragment length polymorphism (T-RFLP) profiling. Species richness and evenness were determined using T-RF band lengths and relative band intensities. RESULTS: From the 64 DNA samples, 834 bands were detected, of which 179 represented different species (operational taxonomic units [OTUs]). The average species richness for the FAP-, FAP+, UC-, and UC+ groups was 26, 35, 23.9, and 29.6 per patient, with the average species diversity within the groups of 10.6, 29, 8.3, and 11.4, respectively. Similar trends were observed when the anaerobic and aerobic-derived bacterial groups were analyzed separately. CONCLUSIONS: No significant differences were found between the bacterial cultures derived from any of the clinical groups or between pouchitis and nonpouchitis patients.

Faecal M2-pyruvate kinase: a novel, noninvasive marker of ileal pouch inflammation.

BACKGROUND: Dimeric M2-pyruvate kinase (dM2-PK) is overexpressed in tumour cells with rapid cell turnover. Its concentrations correlate well with the staging and metastatic capability of the tumour cells. We investigated the use of faecal dM2-PK as a noninvasive marker of pouch inflammation (pouchitis) in patients having undergone restorative proctocolectomy. METHODS: Stool samples were obtained from 46 patients with ulcerative colitis (UC) and eight with familial adenomatous polyposis. Pouchitis was defined using the objective pouchitis score (OPS) and the pouch disease activity index. Faecal dM2-PK was measured using a quantitative sandwich-type enzyme immunoassay (ScheBo Biotech UK) and the results compared with reciprocal faecal calprotectin concentrations. RESULTS: Using the OPS, 6 of the 46 patients with UC had pouchitis and prepouch ileitis, 13 had UC pouchitis alone, and 27 had a non-inflamed UC pouch. One patient with familial adenomatous polyposis had pouchitis and prepouch ileitis and 7 had an non inflamed pouch. Respective median dM2-PK values (U/ml) for these five groups were 49.5 (4.5-110), 12 (1-192.3), 2.2 (0.1-95.2), 19.5 and 1 (0.1-3). Statistically significant differences were noted between inflamed and non inflamed pouches (P<0.0001). dM2-PK correlated significantly with the OPS, pouch disease activity index, endoscopic appearances, acute histological and neutrophil scores (<0.0001). The receiver operating characteristic analysis demonstrated a sensitivity and specificity of 80 and 70.6%, respectively. dM2-PK and faecal calprotectin concentrations correlated closely (r=0.87, P<0.0001). CONCLUSION: This study demonstrates that faecal dM2-PK is a sensitive marker of pouch inflammation and that its concentration directly correlates with the objective markers of pouchitis severity.

Faecal calprotectin: a noninvasive diagnostic tool and marker of severity in pouchitis.

INTRODUCTION: In pouchitis, the mucosa is infiltrated by activated polymorphonuclear neutrophils capable of producing calprotectin, a stable antimicrobial myelomonocytic protein. AIM: The aim is to assess the ability of faecal calprotectin to differentiate between inflamed and noninflamed ileal pouches, and to correlate this with inflammation severity using the newly developed Objective Pouchitis Score. METHOD: Fifty-four stool samples were collected from patients who had undergone restorative proctocolectomy; 46 from patients with ulcerative colitis and eight from those with familial adenomatous polyposis coli. Faecal calprotectin concentrations were determined by quantitative enzyme-linked immunosorbant assay. RESULTS: Of the ulcerative colitis patients, six were diagnosed with pouchitis and pre-pouch ileitis (median faecal calprotectin: 865 microg/g, with a range of 95-2350 microg/g); 13 had pouchitis alone (145, 33-3350 microg/g) and 27 were uninflamed (56, 4-705 microg/g). Of the familial adenomatous polyposis patients, one had pouchitis and pre-pouch ileitis (305 microg/g), and seven had noninflamed pouches (9, 6-26 microg/g). Stool samples obtained from pouchitis patients had significantly higher calprotectin concentrations compared with those obtained from uninflamed pouches (Mann-Whitney: P<0.0001). Faecal calprotectin concentrations correlated closely with the Objective Pouchitis Score, the Pouch Disease Activity Index and endoscopic and histological inflammatory scores (Spearman rank test: P values <0.0001). Using a faecal calprotectin threshold of >or=92.5 microg/g to define a positive result, Receiver Operating Characteristic analysis demonstrated a sensitivity of 90% and a specificity of 76.5%. CONCLUSION: Faecal calprotectin measurement is a useful noninvasive tool in the diagnosis of acutely inflamed ileal pouches and correlates well with the severity of pouchitis.