In vivo and in vitro permeability in coeliac disease.

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.