Background: In active coeliac disease, mucosal atrophy is associated with a marked decrease in intestinal disaccharidase enzyme activities. We investigated the value of duodenal mucosal disaccharidases to predict the severity of mucosal villous atrophy and its recovery in 50 patients with coeliac disease.
Methods: Duodenal mucosal histology and disaccharidase activities were studied at least twice with a mean interval of 9 months. Histology of specimens from all patients was examined by the same pathologist blinded to the data on disaccharidase activities. Mucosal damage was scored into four groups as follows: Grade 0 = normal mucosa; grade I = slight villous atrophy, that is, cryptic component 30%-50%; grade 2 = moderate villous atrophy, that is, cryptic component 50%-90%; grade 3 = severe villous atrophy, that is, cryptic component >90%. The enzyme activities of the disaccharidases were determined as U/g protein.
Results: Duodenal mucosal disaccharidase activities were good predictors of the grade of mucosal villous atrophy. Positive predictive values for moderate or severe villous atrophy were 90% for maltase (maltase activity <150 U/g protein), 86% for sucrase (<40 U/g protein) and 71% for lactase (<20 U/g protein). Accordingly, negative predictive values, that is, none or only minimal villous atrophy (grades 0 or 1) with normal disaccharidase activities, were 71% for maltase, 70% for sucrase and 63% for lactase.
Conclusions: The increase in duodenal disaccharidase activities correlated with recovery of the mucosa based on histology. Besides the histological examination, measurement of disaccharidase activities offers an additional tool to evaluate response to a gluten-free diet in patients with coeliac disease.