Cell-mediated immune reaction to colon altered by bacteria.

It has been suggested that enteric bacteria initiate a destructive immunological reaction in ulcerative colitis either because of antigenic similarity to colon (Perlmann, Hammarstr6m, Lagercrantz, and Gustafsson, 1965) or by acting as a hapten (Kirsner, 1965). If this immunity is of the cell-mediated type, it may be demonstrated by a local reaction following intradermal inoculation with a test antigen (Humphrey, 1967). We therefore tested normal adults and patients with ulcerative colitis for skin sensitivity to colon treated with E. coli, colon alone, and E. coli alone.