Coeliac disease in primary care: evaluation of a case-finding strategy.

BACKGROUND: Coeliac disease is still under-diagnosed as a consequence of poor physician awareness of the clinical spectrum of the disease. We evaluated the feasibility and the cost-effectiveness of a case-finding approach for early identification of cases, carried out by primary care practitioners. METHODS: We developed a case-finding strategy based on testing for anti-tissue transglutaminase IgA antibodies in subjects showing predefined signs and symptoms or belonging to at-risk groups. RESULTS: Sixty-nine primary care doctors and 60 primary care paediatricians agreed to participate. One thousand forty-one adults and 447 children were selected for anti-tissue transglutaminase testing during the year of the study (2001). Thirty-one (2.08%, 19 adults and 12 children) were ultimately diagnosed as coeliac patients. While no cases of coeliac disease had been diagnosed by the participating doctors in the previous year, 29 subjects were diagnosed as coeliacs in the year after the completion of the study (2002). The prevalence of confirmed coeliac disease in the population under study increased from 1:1,506 to 1:1,073 in adults and from 1:827 to 1:687 in children from year 2000 to 2001. When cases diagnosed in 2002 are included, the prevalence is 1:832 and 1:602, respectively. We calculated a cost of 923.25 euros for each new case diagnosed. CONCLUSIONS: Case-finding is a feasible and successful strategy for detecting undiagnosed coeliac patients and has the important added value of increasing the awareness of the disease among primary care physicians; it represents a cost-effective alternative to population screening for reducing the burden of undiagnosed coeliac disease.

The role of antitissue transglutaminase assay for the diagnosis and monitoring of coeliac disease: a French-Italian multicentre study.

AIMS: Tissue transglutaminase (tTG) was recently identified as the major autoantigen in coeliac disease. The aim of this multicentre study was to evaluate the impact of a new immunoenzymatic assay for the detection of IgA anti-tGT antibodies. METHODS: Seventy four Italian and French clinical laboratories participated in this study; anti-tTG IgA with an enzyme linked immunosorbent assay (ELISA) method using guinea pig liver extract as the coating antigen, anti-endomysium IgA autoantibodies (EMA), and total serum IgA were determined in 7948 patients, 1162 of whom had coeliac disease (737 untreated cases and 425 on a gluten free diet). A proportion of the sera were then sent to a reference laboratory for anti-tTG retesting with an ELISA method using recombinant human tTG antigen. RESULTS: Seven thousand four hundred and fifty eight (93.8%) sera were EMA/antiguinea pig tTG concordant (positive or negative); 490 (6.2%) were non-concordant. The sensitivity of EMA and antiguinea pig tTG in the 737 untreated patients with coeliac disease was 92.1% and 94.8%, respectively, and the specificity was 99.8% and 99.2%, respectively. Retesting of the discordant sera showed that of the 162 sera classified as EMA negative/antiguinea pig tTG positive, only 49 were positive for human recombinant anti-tTG, and that 39 of these were also EMA positive. Furthermore, of the 36 sera classified as EMA positive/antiguinea pig tTG negative, only two were confirmed as EMA positive. CONCLUSIONS: The antiguinea pig tTG assay is more sensitive but less specific than EMA, whereas the antihuman recombinant tTG assay is far more specific and just as sensitive as antiguinea pig tTG. Testing for EMA presents considerable interpretative problems and is difficult to standardise.

Prevalence of autoimmune disorders in relatives of patients with celiac disease.

Celiac disease (CD) is frequently associated with an autoimmune disorder (AD). The aim of the study was to establish if an AD is more frequent than expected in relatives of CD patients and, in particular, if it is related to the presence of silent unrecognised CD. We also evaluated the prevalence of ADs in CD patients and compared it with that in a control series. A structured questionnaire was used to evaluate the prevalence of ADs in 125 (51 males and 74 females with a mean age of 8.9 years) children with CD (group A), 125 (67 males and 58 females with a mean age of 8.1 years) matched "healthy" children (group B), all 1352 first- and second-degree relatives of the 125 children with CD (group C), all 1238 first- and second-degree relatives of the control group B of "healthy" children (group D), and all 205 first- and second-degree relatives of 20 children with AD (group E). We also used the antiendomysium antibody assay to screen 354 of the 373 first-degree relatives of group C. An AD was present in 9 of the 125 (7.2%) children with CD (group A), in 1 of the 125 (0.8%) healthy children (group B), in 67 of the 1352 (4.9%) relatives of CD patients (group C), in 14 of the 1238 (1.1%) relatives of healthy children (group D), and in 7 of the 205 (3.4%) of relatives of patients with AD (group E). Clinically silent CD was found in 20 of the 354 first-degree relatives of CD patients (5.6%), and the risk of silent CD was significantly higher, reaching 25% (4/16) in the subgroup of relatives also affected by another AD. Relatives of CD patients had an increased prevalence of AD compared to control groups, and relatives of CD patients with ADs, have a risk as high as 25% of being silent celiacs: they should thus be screened for CD.

Detection of Helicobacter pylori cagA gene by polymerase chain reaction in faecal samples.

OBJECTIVE: The polymerase chain reaction (PCR) has been extensively and successfully used to detect Helicobacter pylori in gastric juice and gastric biopsies. In contrast, the results obtained using faeces as biological samples for PCR are rather conflicting. This may be due to the presence of faecal inhibitory compounds (polysaccharides) which can inhibit the amplification reaction. The aim of this study was to characterize the H. pylori genotype in faecal samples by using specific primers for the cagA gene. To overcome the problem of contamination by polysaccharides, we used a filter-based extraction technique already applied in a previous study. METHODS: Antral and body biopsies were obtained from 30 symptomatic patients undergoing upper endoscopy. PCR was used to detect the presence of H. pylori organisms in faecal samples by using primers selected for the urease gene A. In addition, H. pylori organisms were characterized both in faecal samples and paraffin-embedded biopsies by PCR with specific primers for the cagA gene. RESULTS: All patients showed a positive CLO test (rapid urease test) and evidence of H. pylori by Warthin-Starry stain. PCR detected the urease A gene in the faecal samples of all patients. The cagA gene was detected in the faecal and biopsy samples of 18 subjects (60%). Duodenal ulcer and/or antral erosions were observed in 15 of the 18 cagA-positive patients (83.3%) and in five of the 12 cagA-negative patients (41.7%). Endoscopic features of normal mucosa or gastritis were observed in three cagA-positive patients (16.7%) and in seven cagA-negative patients (56.3%). cagA-positive status was found to be significantly related to the endoscopic features of duodenal ulceration and/or antral erosions. CONCLUSIONS: Our findings prove that faeces are suitable samples for the detection of cagA status. Moreover, they confirm the existence of a significant relationship between cagA-positive status and duodenal ulcer and/or antral erosions.