Role of magnified ileoscopy in the diagnosis of cases of coeliac disease with predominant abdominal symptoms

Severity of coeliac disease and clinical management study when using a non-metabolised medication: a phase I pharmacokinetic study

OBJECTIVE

The non-metabolised antihistamine fexofenadine has oral absorption resulting from transporter activity. Uptake by enterocyte organic anion transporting polypeptides and efflux by an ATP-binding cassette transporter (P-glycoprotein) are primary determinants. Coeliac disease-mediated lesions to the small intestinal mucosa may alter oral absorption of the drug probe, fexofenadine.

DESIGN

A phase I, open-label, single-dose, pharmacokinetic study SETTING: London, Ontario, Canada PARTICIPANTS: Patients with coeliac disease (n=41) with positive serology and healthy individuals (n=48).

MAIN OUTCOME MEASURES

Patients with coeliac disease-duodenal histology and oral fexofenadine pharmacokinetics within a 3-week period. Healthy individuals-oral fexofenadine pharmacokinetics with water and grapefruit juice.

RESULTS

Patients with coeliac disease were stratified by disease severity: Group A (n=15, normal), B+C (n=14, intraepithelial lymphocytosis with/without mild villous blunting) and D (n=12, moderate to severe villous blunting). Patients with coeliac disease in groups A, B+C and D and healthy individuals receiving water had similar fexofenadine AUC0-8 (2038±304, 2259±367, 2128±410, 1954±138 ng.h/mL; p>0.05; mean±SEM) and Cmax (440±73, 513±96, 523±104, 453±32 ng/mL; p>0.05), respectively. These four groups all had higher fexofenadine AUC0-8 (1063±59; p<0.01) and Cmax (253±18; p<0.05) compared with those for healthy individuals receiving grapefruit juice. Coeliac groups had a positive linear trend between disease severity and fexofenadine Tmax (2.0±0.3, 2.7±0.4, 3.1±0.5 hours; p<0.05).

CONCLUSIONS

Coeliac disease severity based on duodenal histopathology did not affect oral fexofenadine bioavailability. Increased Tmax suggested absorption distal to the duodenum (jejunum + ileum), where histology seems more normal which may be the key determinant. Patients with coeliac disease may not require consideration for alternative clinical drug management for a number of non-metabolised and transport-mediated medications.

Increased Fecal Bile Acid Excretion in a Significant Subset of Patients with Other Inflammatory Diarrheal Diseases

BACKGROUND

Increased fecal bile acid excretion (IBAX) occurs in a third of patients with functional diarrhea.

AIMS

To assess the prevalence of IBAX in benign inflammatory intestinal and colonic diseases presenting with chronic diarrhea.

METHODS

All patients with known inflammatory diseases or resections who underwent 48 h fecal fat and BA testing for chronic diarrhea at a single center were included. Quiescent disease was based on clinical evaluation and serum, endoscopic and imaging studies. IBAX was defined by: > 2337 µmol total BA/48 h; or primary fecal BAs > 10%; or > 4% primary BA plus > 1000 µmol total BA /48 h. Demographics, fecal weight, fecal fat, stool frequency and consistency were collected. Nonparametric statistical analyses were used for group comparisons.

RESULTS

Sixty patients had celiac disease (51 quiescent, 9 active), 66 microscopic colitis (MC: 34 collagenous, 32 lymphocytic), 18 ulcerative colitis (UC), and 47 Crohn's disease (CD). Overall, fecal fat, 48 h stool weight, frequency and consistency were not different among subgroups except for inflammatory bowel disease (IBD) based on disease location. Almost 50% patients with celiac disease and MC had IBAX, with a greater proportion with increased primary fecal BA. Among UC patients, rates of IBAX were higher with pancolonic disease. A high proportion of patients with ileal resection or CD affecting ileum or colon had IBAX. IBAX was present even with quiescent inflammation in UC or CD.

CONCLUSIONS

A significant subset of patients with MC, quiescent celiac disease and IBD had increased fecal BA excretion, a potential additional therapeutic target for persistent diarrhea.

An unusual method of diagnosing a common disease

A 34-year-old woman presented with non-bloody diarrhoea of 14 days duration and vomiting. Physical examination was unremarkable. She had hypokalaemia and metabolic acidosis. Stool studies were negative for Clostridium difficile toxin, faecal leucocytes and parasites. Colon appeared normal on colonoscopy. Pronounced scalloping of ileal folds was noted on ileoscopy. Ileal biopsies revealed villous blunting, crypt hyperplasia, marked intraepithelial lymphocytosis and lymphocytic infiltration of the lamina propria, consistent with lymphocytic ileitis in coeliac disease. Serology revealed elevated antitissue transglutaminase IgA antibodies (>100 U/ml). Institution of a strict gluten free diet resulted in complete resolution of symptoms. Although rare, coeliac disease can present as an acute diarrhoeal illness and should be considered after infectious aetiologies are excluded.