Histology of the terminal ileum in coeliac disease

Background: The histological lesion of gluten sensitivity primarily affects the proximal small bowel. The purpose of this study was to assess whether there were features of gluten‐sensitive enteropathy in biopsies taken from the terminal ileum during colonoscopy/ileoscopy. Specific and sensitive abnormalities might facilitate diagnosis of coeliac disease in patients undergoing colonoscopy as their initial procedure or help select those who should proceed to upper gastrointestinal endoscopy and duodenal biopsy. Methods: Terminal ileal biopsies, taken from 30 patients with duodenal villous atrophy consistent with coeliac disease and from 60 control patients with no evidence of coeliac or inflammatory bowel disease, were reviewed blindly and compared. Biopsies were assessed for the presence or absence of villous atrophy and crypt hyperplasia, and counts were made of intraepithelial lymphocytes (IELs). Results: One patient only, in the coeliac group, had partial villous atrophy with crypt hyperplasia in the terminal ileum. IEL counts were significantly higher (P?Conclusions: Coeliac disease may affect the entire small bowel. Increased IEL density in the terminal ileum is associated with duodenal VA and should prompt a search for coeliac disease by serology and duodenal biopsy. Conversely, a normal IEL count does not allow the exclusion of coeliac disease with confidence.     

Inflammatory disease of the terminal ileum

Digestive Diseases and Sciences -     

Carcinoid tumour of the terminal ileum simulating Crohn disease

Carcinoid tumours are often difficult to diagnose because of obscure or non-specific symptoms. Two cases of ileal carcinoid are reported in whom the diagnosis was delayed as the symptoms and small-bowel series were thought to be consistent with Crohn disease. This report emphasizes the difficulties of diagnosing carcinoid by conventional radiological methods. Ileal carcinoid should be considered in the differential diagnosis of Crohn disease, particularly in elderly patients presenting with chronic recurrent symptoms.     

Focal segmental ischemia of the terminal ileum mimicking Crohn's disease

The clinical, radiographic, and pathologic features of focal segmental ischemia are similar to Crohn's disease. We report a patient with focal segmental ischemia mimicking Crohn's disease and discuss the histologic distinction between the two entities. Ischemia must be considered when "Crohn's-like" lesions are encountered in elderly patients.     

Endoscopy of the terminal ileum

A prospective study was undertaken to investigate the feasibility and diagnostic yield of ileoscopy as an extension of total colonoscopy. The distal 15 to 40 cm of the terminal ileum were visualized in 400 of 555 consecutive patients submitted to total colonoscopy (72 percent). Intubation of the terminal ileum was not successful in 42 patients (8 percent), not tried in 63 (11 percent), and hampered by inadequate colonic cleansing in 50 (9 percent). We observed 13 patients with terminal ileitis and seven rare findings such as nonspecific ileal ulcer or non-Meckelian diverticulum, etc., adding to a total of 20 pathologic findings in 400 examinations (5 percent). In a further group of 98 patients, useful diagnostic information was gained by the demonstration of normal ileal findings, making ileoscopy clinically valuable in 118 of 400 examinations (29.5 percent) in this series. We suggest routine endoscopy of the terminal ileum in all patients with suspected or established inflammatory bowel disease and/or persistent diarrhea, lower gastrointestinal tract bleeding, or irritable bowel syndrome, in whom the diagnostic procedure includes colonoscopy. In patients with colorectal tumors or polyps, the diagnostic yield will be unrewarding.     

Diverticulitis of the terminal ileum

In the past two decades, several reports have documented inflammatory changes in acquired diverticula of the terminal ileum and their associated complications, namely, perforation, intestinal obstruction, gastrointestinal hemorrhage, and fistulization. A comprehensive review revealed 28 cases of diverticulitis of the terminal ileum documented in the world medical literature. Only one case of internal fistula (ileovesical) has been reported previously. This report describes another patient with diverticulitis of the terminal ileum with associated perforation and jejunoileal fistula and reviews the world literature.     

Non-fatal portal pyaemia complicating Crohn's disease of the terminal ileum.

A 40 year old woman with known Crohn's disease of the ileum but no abscess was found to have hepatic portal venous gas by computed tomography. Aggressive antibiotic treatment led to recovery and the ileum was resected two weeks later.     

Why does Crohn's disease usually occur in terminal ileum?

Crohn's disease can affect any part of the gastrointestinal tract, but terminal ileum is the most frequent localization. The reason why Crohn's disease is primarily located in the distal part of the ileum remains unexplained.In this article it has been attempted to provide a compelling explanation why Crohn's disease usually occurs in terminal ileum. Recent data indicate that some individuals are genetically predisposed to develop ileal Crohn's disease. Two genetic alterations, the polymorphism of Caspase Associated Recruitment Domain (CARD15) and Carcinoembryonic Antigen-related Cell Adhesion Molecule 6 (CEACM6), favour the colonization of terminal ileum by entero adherent-invasive Escherichia coli (AIEC). The adhesion of these bacteria to epithelial intestinal cells depends on Carcinoembryonic Antigen-related Cell Adhesion Molecule 6 expression in ileal epithelial cells and on the reduced ileal defensins expressed in a CARD15 dependent manner. Genetic defects in Authophagy-related 16-like gene (ATG16L1) and Immunity-related Guanosine Triphospatase (IRGM) recently found in ileal CD patients lead to a reduction of bacterial killing by macrophages and consequent continuous immunological upstimulation, cytokine secretion, chronic inflammation of the ileum and tissue injury. On the basis of all these data Crohn's disease of the ileum seems to be a subset of the disease mainly genetically determined.     

Matrix metalloproteinases as profibrotic factors in terminal ileum in Crohn's disease

BACKGROUND: Returning stenosis in Crohn's disease (CD) patients is poorly understood. After resection, newly developed strictures are seen within 10 years in 50% to 70%. Matrix metalloproteinases (MMPs) are involved in matrix-turnover processes. This study analyzes spatial expression of MMP-1, MMP-3, MMP-9, tissue inhibitor of MMP-1, and collagen III to get better insight in tissue remodeling of terminal ileum of CD patients. METHODS: Expressions were analyzed on mRNA and the protein level (MMP-1, MMP-3) in segments from resected terminal ileum from CD and control patients. In CD, macroscopic distinction was made between proximal resection margin, prestenotic, and stenotic tissue. Immunohistochemistry allowed for expression analyses transmurally. RESULTS: MMP-1 and MMP-3 gene expression was up-regulated (P < 0.05) in both prestenotic and stenotic tissue. MMP-1 protein was significantly up-regulated in submucosal and muscular tissue of prestenotic parts and in muscular tissue of stenotic Crohn samples. MMP-3 protein was significantly up-regulated in all layers of prestenotic and stenotic Crohn samples. Even in submucosa of proximal resection margin tissue, MMP-3 expression was significantly higher than in controls. CONCLUSION: Surprisingly, in proximal resection margin tissue up-regulated MMP-3 was seen. This suggests that in nonresected terminal ileum, in which anastomosis is made, tissue turnover is present, which may account for the high recurrence of intestinal strictures.     

Bile acid metabolism in patients with Crohn's disease in terminal ileum

Bile acid metabolism was studied by means of the fractional turnover rate or orally ingested 14C-labeled taurocholic acid and by gas chromatographic determination of fecal excretion of the bile acids cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), and lithocholic acid (LCA). Thirty patients with Crohn's disease (CD) of the small bowel, of whom 19 had been operated on with limited ileal resections, were studied and compared with 11 healthy volunteers. The unoperated group of CD patients did not show significant increase in bile acid excretion in the stools in contrast to the CD patients with ileal resection. The fecal excretion consisted mostly of primary bile acids, and a significant correlation between length of resection and bile acid excretion was found (rs = 0.81, p less than 0.01). The fractional turnover rate of CA + DCA was significantly increased in both unoperated (0.21 l/day) and operated (0.44 l/day) patients compared with normal controls (0.06 l/day). The bile acid pool of CA + DCA, however, was normal in patients with ileal resections, indicating a compensatory increase in bile acid synthesis. In unoperated patients the bile acid pool of CA + DCA was slightly decreased (3.1 mmol) compared with operated patients (6.2 mmol) and normal controls (4.8 mmol). The pool size was not significantly correlated to mean transit time of dietary residue, feces excretion, loss of weight, or amount of fat in feces. The mean transit time of dietary residue was decreased in both operated and unoperated CD patients.     

The occurrence of terminal ileal histological abnormalities in patients with coeliac disease

INTRODUCTION: Coeliac disease causes histological changes throughout the small bowel, but is often a proximal lesion. We wanted to assess whether terminal ileal histological abnormalities occurred more commonly in patients with coeliac disease and if specific assessment of intraepithelial lymphocytes increases the recognition of undiagnosed coeliac disease. METHODS: Terminal ileal biopsies were prospectively examined over a 3-year period (April 2001-May 2004). Patients were included if they were found to have a synchronous duodenal biopsy that gave a new diagnosis of coeliac disease (n=20). Terminal ileal biopsies taken at colonoscopy during the same period were also examined from four groups of patients: coeliac disease established on a gluten-free diet but with persisting symptoms (n=25), inflammatory bowel disease (n=47), chronic diarrhoea (n=44) and polyp surveillance (n=47). All biopsies were graded according to the Marsh criteria and an intraepithelial lymphocytes count per 100 enterocytes was obtained. RESULTS: There was only one patient from all five groups who had villous atrophy of the terminal ileal. This patient had a new diagnosis of coeliac disease. The mean intraepithelial lymphocytes count in the coeliac disease group was 23.7 intraepithelial lymphocytes/100 enterocytes. This was significantly higher than the control groups: coeliac disease on a gluten-free diet=17.5 (p<0.012), inflammatory bowel disease=12.3 (p<0.0001), diarrhoea=12.6 (p<0.0001) and polyp=13.7 (p<0.0002). Validating terminal ileal villous intraepithelial lymphocytes counts as a test for coeliac disease using an intraepithelial lymphocytes/100 enterocytes of >25 gives a sensitivity of 45% and a specificity of 97.8%. CONCLUSION: Routinely quantifying terminal ileal intraepithelial lymphocytes may be of limited clinical value. However, subjective recognition of raised intraepithelial lymphocytes on a terminal ileal biopsy should alert the clinician to the possibility of coeliac disease.