Diagnostic Yield of 2 Strategies for Adult Celiac Disease Identification in Primary Care.

GOALS: To compare the diagnostic yield and cost-consequences of 2 strategies, screening regardless of symptoms versus case finding (CF), using a point-of-care test (POCT), for the detection of celiac disease (CD) in primary care, to bridge the diagnostic gap of CD in adults. MATERIALS AND METHODS: All subjects under 75 years of age who consecutively went to their general practitioners' offices were offered POCT for anti-transglutaminase immunoglobulin A antibodies. The POCT was performed on all subjects who agreed, and then a systematic search for symptoms or conditions associated with higher risk for CD was performed, immediately after the test but before knowing the test results. The 2 resulting groups were: (a) POCT positive and (b) symptomatic subject at CF. Subjects were defined as symptomatic at CF in the presence of 1 or more symptoms. All POCT-positive or symptomatic subjects at CF were referred to the CD Centers for confirmation of CD. Data on resource consumption were gathered from patients' charts. Cost of examinations, and diagnostic and laboratory tests were estimated with regional outpatient tariffs (Sicily), and a price of &OV0556;2.5 was used for each POCT. RESULTS: Of a total of 2197 subjects who agreed to participate in the study, 36 (1.6%) and 671 (30.5%) were POCT positive and symptomatic at CF, respectively. The yield from the screening and CF was 5 new celiac patients. The total cost and mean cost for each new CD case were &OV0556;7497.35 and &OV0556;1499.47 for the POCT screening strategy, and &OV0556;9855.14 and &OV0556;1971.03 for the CF strategy, respectively. Assuming consecutive use of both strategies, performing POCT only in symptomatic subjects at CF, the calculated yield would be 4 new diagnoses with a total cost of &OV0556;2345.84 and a mean cost of &OV0556;586.46 for each newly diagnosed patient. Only 1 patient was celiac despite a negative POCT. CONCLUSIONS: Testing symptomatic subjects at CF only by POCT seems the most cost-effective strategy to bridge the diagnostic gap of adult CD in primary care.

The importance of disease prevalence in assessing the diagnostic value of a test: endoscopic markers in celiac disease.

BACKGROUND/AIMS: We evaluated the diagnostic variability and reproducibility of endoscopic signs in two populations with a different pretest likelihood of celiac disease (CD). METHODS: We recruited 289 CD patients (both adults and children) in a multicenter prospective study. Group 1 (high risk) included 111 patients referred for positive serology. Group 2 (low risk) included 178 unselected patients. Mosaic pattern, reduction/loss of Kerckring's folds, scalloping of the valvulae conniventes and a nodular pattern were the endoscopic findings looked for in the duodenum. RESULTS: In group 1, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of endoscopic findings were 100, 84.6, 94.2 and 100% in adults, and 86.8, 9.1, 82.1 and 12.5% in children. In group 2, the sensitivity, specificity, PPV and NPV of endoscopic findings were 33.3, 91.4, 7.7 and 98.5% in adults, and noncalculable, 78.3, 0.0 and 100% in children. Comparing group 1 and group 2, there was a statistically significant difference in sensitivity and PPV in adults, and in specificity, PPV and NPV in children. Concerning the reproducibility of endoscopic findings, a wide variability of κ values was found. CONCLUSION: Endoscopic signs have low reproducibility for CD, and their diagnostic value in selecting patients for multiple intestinal biopsies is unacceptable, especially in populations with low disease prevalence.

Prevalence of celiac disease in adult patients with refractory functional dyspepsia: value of routine duodenal biopsy.

AIM: To investigate the prevalence of celiac disease (CD) in adult patients referred to an open access gastroenterology clinic in the south of Italy and submitted to esophago-gastro-duodenoscopy (EGD) for evaluation of refractory functional dyspepsia. METHODS: Seven hundred and twenty six consecutive dyspeptic patients (282 male, 444 female; mean age 39.6 years, range 18-75 years) with unexplained prolonged dyspepsia were prospectively enrolled. Duodenal biopsies were taken and processed by standard staining. Histological evaluation was carried out according to the Marsh-Oberhuber criteria. RESULTS: The endoscopic findings were: normal in 61.2%, peptic lesions in 20.5%, malignancies in 0.5%, miscellaneous in 16.7%. CD was endoscopically diagnosed in 8 patients (1.1%), histologically in 15 patients (2%). The endoscopic features alone showed a sensitivity of 34.8% and specificity of 100%, with a positive predictive value (PPV) of 100% and a negative predictive value (NPP) of 97.9%. CONCLUSION: This prospective study showed that CD has a high prevalence (1:48) in adult dyspeptic patients and suggests the routine use of duodenal biopsy in this type of patient undergoing EGD.

A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease.

BACKGROUND: Treatment of celiac disease (CD) is based on the avoidance of gluten-containing food. However, it is not known whether trace amounts of gluten are harmful to treated patients. OBJECTIVE: The objective was to establish the safety threshold of prolonged exposure to trace amounts of gluten (ie, contaminating gluten). DESIGN: This was a multicenter, double-blind, placebo-controlled, randomized trial in 49 adults with biopsy-proven CD who were being treated with a gluten-free diet (GFD) for > or =2 y. The background daily gluten intake was maintained at < 5 mg. After a baseline evaluation (t0), patients were assigned to ingest daily for 90 d a capsule containing 0, 10, or 50 mg gluten. Clinical, serologic, and histologic evaluations of the small intestine were performed at t0 and after the gluten microchallenge (t1). RESULTS: At t0, the median villous height/crypt depth (Vh/Cd) in the small-intestinal mucosa was significantly lower and the intraepithelial lymphocyte (IEL) count (x 100 enterocytes) significantly higher in the CD patients (Vh/Cd: 2.20; 95% CI: 2.11, 2.89; IEL: 27; 95% CI: 23, 34) than in 20 non-CD control subjects (Vh/Cd: 2.87; 95% CI: 2.50, 3.09; IEL: 22; 95% CI: 18, 24). One patient (challenged with 10 mg gluten) developed a clinical relapse. At t(1), the percentage change in Vh/Cd was 9% (95% CI: 3%, 15%) in the placebo group (n = 13), -1% (-18%, 68%) in the 10-mg group (n = 13), and -20% (-22%, -13%) in the 50-mg group (n = 13). No significant differences in the IEL count were found between the 3 groups. CONCLUSIONS: The ingestion of contaminating gluten should be kept lower than 50 mg/d in the treatment of CD.

Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines.

OBJECTIVE: Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. MATERIAL AND METHODS: Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression was evaluated by real-time polymerase chain reaction (PCR). RESULTS: When exposed to gliadin, zonulin receptor-positive IEC6 and Caco2 cells released zonulin in the cell medium with subsequent zonulin binding to the cell surface, rearrangement of the cell cytoskeleton, loss of occludin-ZO1 protein-protein interaction, and increased monolayer permeability. Pretreatment with the zonulin antagonist FZI/0 blocked these changes without affecting zonulin release. When exposed to luminal gliadin, intestinal biopsies from celiac patients in remission expressed a sustained luminal zonulin release and increase in intestinal permeability that was blocked by FZI/0 pretreatment. Conversely, biopsies from non-celiac patients demonstrated a limited, transient zonulin release which was paralleled by an increase in intestinal permeability that never reached the level of permeability seen in celiac disease (CD) tissues. Chronic gliadin exposure caused down-regulation of both ZO-1 and occludin gene expression. CONCLUSIONS: Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.