BCG treatment of Crohn's disease.

Among 53 patients with documented Crohn's disease, 30% manifested a defect in delayed hypersensitivity demonstrated by negative DNCB skin tests and significant (p less than 0.01) T-lymphocyte hyporeactivity. A double-blind controlled trial was conducted to evaluate oral Bacillus Calmette-Guerin (BCG) therapy in nine of these patients with Crohn's disease and deficient cellular immunity. All patients had a Crohn's Disease Activity Index (CDAI) greater than 150 (at least moderate activity) upon randomization to BCG (five patients) or placebo (four patients) treatment for six to 12 months. No significicant differences between BCG and placebo treatment were found in the CDAI, laboratory tests and gastrointestinal roentgenograms. We conclude that the disturbance in cell-mediated immunity in patients with Crohn's disease probably is a manifestation of the disease rather than an etiological factor and that immunostimulation with oral BCG is not effective therapy.