Immunological studies on Crohn's disease. II. Lack of evidence for humoral and cellular dysfunctions.

In 16 patients with Crohn's disease, we attempted to determine possible alterations in humoral and/or cellular immunologic dysfunctions. We examined the antinuclear, antithyroglobulin and antimicrosomal autoantibodies, circulating immunoglobulin levels and complement components. To clarify the significance of cellular immunity in Crohn's disease, mitogenic lymphocyte transformation and concanavalin A-induced suppressor cell activities were studied. Evidence for humoral and cellular immunological abnormalities was not obtained. The correlation between these immunological parameters and disease activity was also nil. These results suggest that Crohn's disease may not be an immunodysfunctional disorder such as systemic lupus erythematosus, but rather a multifactorial disease. The immunological abnormalities reported in the literature may represent phenomena related to states of malnutrition, since the patients we studied were clinically not in a severe stage of the disease.