Serum Immunoglobulins and Organ‐specific, Cellular Hypersensitivity in Ulcerative Colitis and Crohn's Disease

Abstract The serum concentrations of IgG, IgA, and IgM have been measured in 22 patients with ulcerative colitis and in 23 patients with Crohn's disease. The concentration of IgG was significantly higher in ulcerative colitis than in Crohn's disease, but the examination did not show any major differences between the two conditions or alterations from the normal. In Crohn's disease the serum concentration of IgG was lower in patients treated than in patients not treated with glucocorticoids. A similar difference was not found in ulcerative colitis. In a parallel study on the same patients the in vitro inhibition of leucocyte migration induced by jejunoileal and colonic mucosa components was examined. A reactivity, which is probably an in vitro correlate to organ‐specific, cellular hypersensitivity to intestinal mucosa components, was demonstrated in a majority of the patients with ulcerative colitis, whereas patients with Crohn's disease did not differ significantly from contro's. There was no correlation between the serum concentration of the various immunoglobulins and the result of the leucocyte migration test. As important fluctuations in production, catabolism, extravascular deposit, and loss of immunoglobulins may be concealed behind comparatively normal serum immunoglobulin concentrations, more conclusive results may be gained from examinations which include metabolic studies of the immunoglobulins.