Possible diagnostic test for Crohn's disease by use of buccal mucosa.

Immunofluorescent tracing was used on buccal mucosa from patients with Crohn's disease to investigate some of its immunological characteristics, and to compare these with those of mucosa from controls. Normal buccal mucosa from patients with Crohn's disease, incubated with its own serum then stained for deposited antibody by the fluorescent technique, showed a positive reaction, not observed in buccal mucosa from normal persons or patients with ulcerative colitis. These observations could provide the basis of a diagnostic test.