Background: An increased permeability to sugars is found in the intestine of untreated patients with coeliac disease after oral ingestion.
Aim: To test whether in vitro permeability resembles in vivo permeability tests and whether an in vitro gliadin gluten challenge could be performed by an in vitro permeability test.
Methods: We measured in vivo (urinary excretion after sucrose-lactulose-mannitol ingestion) and in vitro permeability (by mini-Ussing chambers) in 25 healthy controls, 12 relatives of coeliac disease patients, 19 treated, eight partly treated and 16 untreated patients with coeliac disease.
Results: In vivo sugar permeability was increased in nearly all coeliac patients. Additionally, in vitro permeability to lactulose (P=0.0007), mannitol (P=0.004) and sucrose (P=0.042) was higher in untreated patients with coeliac disease. It correlated with in vivo permeability (sucrose tau=0.61, P=0.006; lactulose tau=0.41, P < 0.0001; mannitol tau=- 0.56, P=0.62) and was dependent on mucosal damage. An in vitro gliadin challenge over 24 h could not significantly change in vitro permeability in treated patients with coeliac disease.
Conclusions: An in vitro permeability test capable of measuring elevated permeability in coeliac mucosa was described, but this test cannot replace oral gluten challenge by in vitro gliadin incubation.