Use of the lactose H2 breath test to monitor mucosal healing in coeliac disease

Confirmation of the diagnosis of coeliac disease requires unequivocal evidence of recovery on a gluten-free diet. The lactose H2 breath test is a non-invasive technique for detecting lactose malabsorption, and this may occur in untreated coeliac disease. The utility of this test was investigated in objectively confirming a response to gluten exclusion. The study included 44 children from 0.9 to 14.75 y of age (median 3.2) with coeliac disease. Five children were asymptomatic, being identified through coeliac antibody screening. Breath tests were performed prior to dietary treatment. If positive, they were repeated at 4-wk intervals following gluten exclusion. Overall, 21/44 (48%) children had positive breath tests at presentation. In 18/21 children on a gluten-free diet, this became negative after 4 wk (86%) and in all the children by 8 wk. In two children with positive tests at 4 wk, problems with dietary adherence were identified. A positive test before treatment was not associated with significant differences in individual symptoms, height, weight and body mass index standard deviation scores, serum haemoglobin or albumin. However, no positive results were found in the asymptomatic patients (p = 0.05). Lactose malabsorption was associated with earlier age of presentation (p = 0.008). CONCLUSION: The lactose H2 breath test objectively confirms a response to gluten exclusion. In selected cases it can help confirm a diagnosis of coeliac disease. However, the test tends to be less informative in asymptomatic patients, and in older children.