Matthew W. Johnson

The bacteriology of pouchitis: a molecular phylogenetic analysis using 16S rRNA gene cloning and sequencing.

Objective:To identify, compare, and contrast the microbiota in patients with and without pouchitis after restorative proctocolectomy (RPC) for ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Summary Background Data:Pouchitis is the most common complication following RPC. An abnormal host-microbial interaction has been implicated. We investigated the pouch microbiota in patients with and without pouchitis undergoing restorative proctocolectomy for UC and FAP. Methods:Mucosal pouch biopsies, taken from 16 UC (pouchitis 8) and 8 FAP (pouchitis 3) patients were analyzed to the species (or phylotype) level by cloning and sequencing of 3184 full-length bacterial 16S rRNA genes. Results:There was a significant increase in Proteobacteria (P = 0.019) and a significant decrease in Bacteroidetes (P = 0.001) and Faecalibacterium prausnitzii (P = 0.029) in the total UC compared with the total FAP cohort, but only limited differences were found between the UC nonpouchitis and pouchitis groups and the FAP pouchitis and nonpouchitis groups. Bacterial diversity in the FAP nonpouchitis group was significantly greater than in UC nonpouchitis (P = 0.019) and significantly greater in UC nonpouchitis compared with UC pouchitis (P = 0.009). No individual species or phylotype specifically associated with either UC or FAP pouchitis was found. Conclusions:UC pouch patients have a different, less diverse, gut microbiota than FAP patients. A further reduction in bacterial diversity but no significant dysbiosis occurs in those with pouchitis. The study suggests that a dysbiosis occurs in the ileal pouch of UC RPC patients which predisposes to, but may not directly cause, pouchitis.

Celiac disease: Management of persistent symptoms in patients on a gluten-free diet

AIM To investigate all patients referred to our center with non-responsive celiac disease (NRCD), to establish a cause for their continued symptoms. METHODS We assessed all patients referred to our center with non-responsive celiac disease over an 18-mo period. These individuals were investigated to establish the eitiology of their continued symptoms. The patients were first seen in clinic where a thorough history and examination were performed with routine blood work including tissue transglutaminase antibody measurement. They were also referred to a specialist gastroenterology dietician to try to identift any lapses in the diet and sources of hidden gluten ingestion. A repeat small intestinal biopsy was also performed and compared to biopsies from the referring hospital where possible. Colonoscopy, lactulose hydrogen breath testing, pancreolauryl testing and computed tomography scan of the abdomen were undertaken if the symptoms persisted. Their clinical progress was followed over a minimum of 2 years. RESULTS One hundred and twelve consecutive patients were referred with NRCD. Twelve were found not to have celiac disease (CD). Of the remaining 100 patients, 45% were not adequately adhering to a strict gluten-free diet, with 24 (53%) found to be inadvertently ingesting gluten, and 21 (47%) admitting non-compliance. Microscopic colitis was diagnosed in 12% and small bowel bacterial overgrowth in 9%. Refractory CD was diagnosed in 9%. Three of these were diagnosed with intestinal lymphoma. After 2 years, 78 patients remained well, eight had continuing symptoms, and four had died. CONCLUSION In individuals with NRCD, a remediable cause can be found in 90%: with continued gluten ingestion as the leading cause. We propose an algorithm for investigation.

Polymorphisms near TBX5 and GDF7 are associated with increased risk for Barrett's esophagus.

Background & Aims Barretts esophagus (BE) increases the risk of esophageal adenocarcinoma (EAC). We found the risk to be BE has been associated with single nucleotide polymorphisms (SNPs) on chromosome 6p21 (within the HLA region) and on 16q23, where the closest protein-coding gene is FOXF1. Subsequently, the Barretts and Esophageal Adenocarcinoma Consortium (BEACON) identified risk loci for BE and esophageal adenocarcinoma near CRTC1 and BARX1, and within 100 kb of FOXP1. We aimed to identify further SNPs that increased BE risk and to validate previously reported associations. Methods We performed a genome-wide association study (GWAS) to identify variants associated with BE and further analyzed promising variants identified by BEACON by genotyping 10,158 patients with BE and 21,062 controls. Results We identified 2 SNPs not previously associated with BE: rs3072 (2p24.1; odds ratio [OR] = 1.14; 95% CI: 1.09–1.18; P = 1.8 × 10−11) and rs2701108 (12q24.21; OR = 0.90; 95% CI: 0.86–0.93; P = 7.5 × 10−9). The closest protein-coding genes were respectively GDF7 (rs3072), which encodes a ligand in the bone morphogenetic protein pathway, and TBX5 (rs2701108), which encodes a transcription factor that regulates esophageal and cardiac development. Our data also supported in BE cases 3 risk SNPs identified by BEACON (rs2687201, rs11789015, and rs10423674). Meta-analysis of all data identified another SNP associated with BE and esophageal adenocarcinoma: rs3784262, within ALDH1A2 (OR = 0.90; 95% CI: 0.87–0.93; P = 3.72 × 10−9). Conclusions We identified 2 loci associated with risk of BE and provided data to support a further locus. The genes we found to be associated with risk for BE encode transcription factors involved in thoracic, diaphragmatic, and esophageal development or proteins involved in the inflammatory response.

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 μg/g, with a range of 95–2350 μg/g); 13 had pouchitis alone (145, 33–3350 μg/g) and 27 were uninflamed (56, 4–705 μg/g). Of the familial adenomatous polyposis patients, one had pouchitis and pre-pouch ileitis (305 μg/g), and seven had noninflamed pouches (9, 6–26 μg/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 ≥92.5 μg/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.

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.

Celiac disease in the elderly

Celiac disease is a common condition that is thought to affect 1 in 200 people throughout Europe and America, with prevalence rates reaching 1:100 in Ireland. Improvements in the sensitivity and specificity of serological testing for celiac disease over the past 15 years have resulted in a larger number of diagnoses being made. Up to 34% of patients with newly diagnosed celiac disease are older than 60 years of age. The symptomatic presentation of celiac disease in elderly patients can be subtle, leading to a considerable delay in diagnosis and potential accumulation of associated secondary complications. Given that celiac disease is associated with significant morbidity and reduced life expectancy, physicians need to be aware of this condition and its occurrence in the current increasingly elderly population. Compliance with a strict gluten-free diet is as easily achieved in elderly patients as in younger patients, and has been reported to reduce the risks of cancer and lymphoma associated with celiac disease. This Review highlights age-related differences in the clinical presentation and investigation of patients with suspected celiac disease.

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.

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.

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. Inflamm Bowel Dis 2009

Hyperbaric oxygen as a treatment for malabsorption in a radiation-damaged short bowel.

Radiation enteritis can be challenging to diagnose and treat. We report the case of a 44-year-old woman who was diagnosed with a squamous cell carcinoma of the cervix in 1978 and treated with hysterectomy and post-operative radiotherapy. Over the next 20 years she required multiple intestinal operations resulting in short bowel syndrome. She became symptomatic of severe hypomagnesaemia which could not be corrected with oral supplementation and which required intravenous magnesium sulfate every 5-7 days for an 11-month period. However, following 25 sessions of hyperbaric oxygen therapy, she was able to discontinue intravenous magnesium and maintain her serum magnesium level with oral treatment. Her weight and stoma output improved. For over 4 years subsequent to this therapy she has not required further intravenous magnesium although has needed temporary nutritional support. Her case is complicated by vitamin A, B and D deficiencies.