Immunoglobulin containing cells in inflammatory bowel disease of the colon: a morphometric and immunohistochemical study.

Immunoglobulin containing cells in rectal and sigmoid colonic mucosa in endoscopically obtained biopsies from 10 patients with ulcerative colitis and 10 patients with Crohn's disease were studied, using an indirect immunoperoxidase technique. These findings were compared with the immunoglobulin containing cell number in colonic biopsies from 10 control patients with no evidence of colitis. In biopsies from the 20 patients with inflammatory bowel disease a marked increase in area of the lamina propria per millimetre mucosa length was found. In ulcerative colitis a marked increase in number of IgG containing cells was observed. In Crohn's disease the increase in IgG containing cell number is dependent on the degree of activity of inflammation. In quiescent of active Crohn's disease of the colon we found a significant increase of the IgM containing cells. The number of IgM containing cells per millimetre mucosa length will differentiate the pathology of Crohn's disease from ulcerative colitis.