Follow-up of coeliac disease with the novel one-hour 13C-sorbitol breath test versus the H2-sorbitol breath test.

BACKGROUND: We recently developed a (13)C-sorbitol breath test ((13)C-SBT) as an alternative to the H(2)-sorbitol breath test (H(2)-SBT) for coeliac disease. In this study we compared the diagnostic properties of the H(2)-SBT and the (13)C-SBT in follow-up of coeliac disease. MATERIAL AND METHODS: Twenty-seven coeliac patients on a gluten-free diet (GFD) performed the breath tests. All had been tested before treatment in the initial study of the (13)C-SBT, in which 39 untreated coeliac patients, 40 patient controls, and 26 healthy volunteers participated. Five gram sorbitol and 100 mg (13)C-sorbitol were dissolved in 250 ml tap water and given orally. H(2), CH(4) and (13)CO(2) were measured in end-expiratory breath samples every 30 min for 4 h. Increased H(2) concentration ≥20 ppm from basal values was used as cut-off for the H(2)-SBT. Sixty minutes values were used as diagnostic index in the (13)C-SBT. RESULTS: (13)CO(2) levels at 60 min increased in 20/26 treated coeliac patients (77%) after GFD, but were significantly lower than in control groups. Out of 20 patients who had a positive H(2)-SBT before GFD, 12 had a negative H(2)-SBT after GFD. Peak H(2) concentrations were not correlated with (13)C-SBT results. CONCLUSION: The study confirms the sensitivity of a one-hour (13)C-SBT for small intestinal malabsorption. The (13)C-SBT has superior diagnostic properties compared with the H(2)-SBT in follow-up of coeliac disease.

Intestinal malabsorption of D-xylose: comparison of test modalities in patients with celiac disease.

OBJECTIVE: The aim of the study was to compare three different D-xylose test modalities for small intestinal malabsorption, using patients with celiac disease and healthy persons as experimental models. MATERIAL AND METHODS: Ninety-one untreated celiac patients, 98 treated celiac patients, and 43 healthy subjects performed the (13)C-D-xylose breath test. 1-h plasma D-xylose levels were measured in 48 untreated patients, 41 treated patients and 41 healthy controls. 4-h urine D-xylose excretion was measured in 47 untreated patients, 51 treated patients and 42 healthy controls. 100 mg of (13)C-D-xylose and 5 g of D-xylose were dissolved in 250 ml tap water and given orally. (13)CO(2) was measured in breath every 30 min for 4 h. Blood was sampled after 1 h, and urine collected after 4 h. RESULTS: Test sensitivity/specificity for celiac disease was 88%/84% with the (13)C-D-xylose breath test, 65%/71% with the 1-h plasma D-xylose test, and 55%/74% with the 4-h urine D-xylose excretion test. Breath test results improved significantly in the treated celiac group compared to untreated patients, but were not normalized compared to healthy controls. No difference was found between 1-h plasma D-xylose levels and 4-h urinary D-xylose excretion in treated celiac patients and healthy controls. CONCLUSIONS: The (13)C-D-xylose breath test was superior to D-xylose testing in plasma and urine for assessment of small intestinal malabsorption with considerably higher sensitivity and specificity for untreated celiac disease.

A novel one-hour 13C-sorbitol breath test versus the H2-sorbitol breath test for assessment of coeliac disease.

OBJECTIVE: The H(2)-sorbitol breath test (H(2)-SBT) has previously been suggested as a screening tool for coeliac disease. We developed an alternative (13)C-sorbitol breath test ((13)C-SBT). The aim of the study was to compare the diagnostic properties of the H(2)-SBT and the (13)C-SBT in a clinical setting. MATERIAL AND METHODS: Thirty-nine coeliac patients, 40 patient controls (mainly patients with irritable bowel syndrome) and 26 healthy volunteers underwent the breath tests. The patients were given an oral load of 5 g sorbitol and 100 mg (13)C-sorbitol dissolved in 250 ml tap-water. H(2), CH(4) and (13)CO(2) concentrations were measured in end-expiratory breath samples every 30 min for 4 h. Increased H(2) concentration > or =20 ppm from basal values was used as the cut-off for the H(2)-SBT. RESULTS: The H(2)-SBT had a sensitivity of 71%, a specificity of 46% versus healthy controls, and a specificity of 25% versus patient controls. Individuals with methane-producing intestinal flora had significantly lower peak H(2) concentrations than non-methane producers. The (13)C-SBT reached maximal combined sensitivity/specificity (74%/85%) for both control groups after 1 h. A diagnostic algorithm which stratified patients into high-, moderate- and low risk for coeliac disease was proposed. Following the algorithm, 62% of coeliac patients were detected with 100% specificity. The (13)C-SBT, but not the H(2)-SBT, correlated with age and serum IgA tissue-transglutaminase antibody levels in coeliac patients. CONCLUSIONS: The novel (13)C-SBT has superior diagnostic properties compared to the H(2)-SBT, which has unsatisfactory specificity in clinical practice. The 1-h (13)C-SBT may be a useful supplemental test when investigating for coeliac disease.