Abstract

The cellobiose/mannitol (Ce/Ma) test is a non-invasive technique for investigating intestinal permeability. In coeliac disease there is a decreased absorption of small molecules and paradoxically increased absorption of large molecules. The simultaneous administration of cellobiose and mannitol as two probe molecules allows the permeability of the small bowel mucosa to be studied, eliminating extraneous factors such as gastric emptying, and incomplete urine collection. One thousand and ten patients presenting to a gastroenterology clinic with symptoms, signs, or biochemical indices compatible with coeliac disease had a Ce/Ma test. Eight hundred and seventeen had a normal test and of these 197 had a jejunal biopsy showing 148 normal mucosa, two coeliac disease, 43 non-specific abnormalities, four giardiasis. One hundred and ninety three had an abnormal test; of these 132 had a jejunal biopsy showing 62 normal mucosa, 48 coeliac disease, and 22 other abnormalities. Considering those who had jejunal biopsies, the sensitivity of the test for coeliac disease is 96%, specificity 70%, the predictive value of the positive 36%, and predictive value of the negative 99%. Eleven per cent of the patients with a 'false positive' test had abnormalities in the jejunal biopsy or a diagnosis which could explain the abnormal permeability.