Follow-up of treated coeliac patients: Sugar absorption test and intestinal biopsies compared

Objective: To determine whether the sugar absorption test (SAT) during follow-up of patients with coeliac disease on a gluten-free diet (GFD) correlates with improvement of the villous architecture of the small intestine. Methods: The SAT was performed in coeliacs at diagnosis and during follow-up with GFD. For the SAT, a solution of lactulose (L) and mannitol (M) was given to the fasting patient and the L-M ratio calculated in a S-hour urine sample by gas chromatography: ratios >0.089 are considered abnormal. The solution was made hyperosmolar by adding sucrose (1560 mmol/l). Results: The L-M ratio was 2-3 times higher at diagnosis than either at 8 months to 2 years gluten free, or beyond 2 years gluten free, consecutively. The L-M ratio (mean, range) was significantly higher in cases of biopsies with (sub)total villous atrophy (VA) (0.388, 0.062-0.804, n=28), partial VA (0.240, 0.062-0.841, n=18) and villous irregularity (0.143, 0.017-0.322, n=29) than in case of normalized histology after GFD (0.085, 0.021-0.230, n=19). The rate of normalization of functional integrity was slower in adults than in children, demonstrated by a combination of histology and SAT. Conclusion: The SAT correlates well with the degree of VA. It is important for daily clinical practice that the simple and non-invasive SAT can be used as an indicator of intestinal damage, thus influencing need for and timing of intestinal biopsies.