A novel one-hour¹³C-sorbitol breath test versus the H₂-sorbitol breath test for assessment of coeliac disease

Abstract

Objective. The H₂-sorbitol breath test (H₂-SBT) has previously been suggested as a screening tool for coeliac disease. We developed an alternative ¹³C-sorbitol breath test (¹³C-SBT). The aim of the study was to compare the diagnostic properties of the H₂-SBT and the ¹³C-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 ¹³C-sorbitol dissolved in 250 ml tap-water. H₂, CH₄ and ¹³CO₂ concentrations were measured in end-expiratory breath samples every 30 min for 4 h. Increased H₂ concentration ≥20 ppm from basal values was used as the cut-off for the H₂-SBT. Results. The H₂-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 H₂ concentrations than non-methane producers. The ¹³C-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 ¹³C-SBT, but not the H₂-SBT, correlated with age and serum IgA tissue-transglutaminase antibody levels in coeliac patients. Conclusions. The novel ¹³C-SBT has superior diagnostic properties compared to the H₂-SBT, which has unsatisfactory specificity in clinical practice. The 1-h ¹³C-SBT may be a useful supplemental test when investigating for coeliac disease.

• Breath test
• carbon isotopes
• coeliac disease
• malabsorption
• sorbitol