Comparative mapping of the local distribution of immunoglobulin-containing cells in ulcerative colitis and Crohn's disease of the colon.

The local response pattern of immunoglobulin-containing cells was compared in Crohn's disease and ulcerative colitis by paired immunohistochemistry on specimens of the large bowel wall. In the "Crohn mucosa" with persisting glands the total cell count was on the average raised more than three times compared with controls. The numbers of IgA, IgM and IgG immunocytes were increased 2.0, 4.8 and 28.6 times, respectively. Only 0-2 IgD- and IgE-containing cells were generally found per section. No consistent differences in the mucosal response pattern were revealed when Crohn's disease was compared with ulcerative colitis. The deeper layers of the bowel wall were in both diseases more or less densely infiltrated by immunocytes-IgG cells compromising about 80%. Immunoglobulin-containing cells in the muscularis propria and subserosa were characteristically found in Crohn's disease. There was no indication of a primary defect in the secretory immunoglobulin system which appeared to be normal in areas with intact glands. The pronounced local humoral immune response, particularly that involving IgG, might be of pathogenetic importance by aggravating and perpetuating in the inflammatory bowel disease.