T-lymphocyte subpopulations in Crohn's disease: definition by monoclonal antibodies.

Thirty-two patients with Crohn's disease (CD) and 32 age- and sex-matched controls were studied for T lymphocytes and T-lymphocyte subpopulations in the peripheral blood, using monoclonal antibodies defining the helper/inducer and the suppressor/cytotoxic compartment. T cells were reduced in patients with CD (P less than 0.05), and this reduction was more pronounced in patients with active disease (P less than 0.01). This T-cell deficiency involves helper and suppressor cells proportionally. The proportion of helper and suppressor cells in CD was independent of disease activity and therapy. We conclude that the T-cell deficiency in CD is a secondary event, and that there is no derangement in the "immunoregulatory ratio" (helper to suppressor cells) in CD which might have served as an explanation for a possible autoimmune mechanism in the pathogenesis of this disease.