Lymphocyte reactivity to Crohn's ileal homogenates.

This study was undertaken to demonstrate whether lymphocytes derived from patients with Crohn's disease and their household contacts would demonstrate increased reactivity upon exposure to tissue homogenates prepared from the terminal ileum of patients with Crohn's disease. It was demonstrated that 4 of 18 patients, 9 of 30 household contacts, and 0 of 13 control subjects exhibited statistically greater lymphocyte thymidine incorporation in response to Crohn's tissue homogenates (contacts vs control, P = 0.025) [Fisher Exact Test (FET)]. However, homogenates prepared from the terminal ileum of control subjects without inflammatory bowel disease also induced lymphocyte reactivity in 1 patient, 5 contacts, and 1 control subject. Factors may be present in homogenates prepared from human terminal ileum which induce lymphocyte reactivity in some patients with Crohn's disease and household contacts.