Biochemical analysis of enzymic markers of inflammation in rectal biopsies from patients with ulcerative colitis and Crohn's disease.

Rectal biopsies were collected from control subjects, patients with ulcerative colitis both active and quiescent, and from patients with Crohn's disease, both with and without rectal involvement, as judged by histological assessment. Tissue homogenates were assayed for neutrophil (vitamin B12 binding protein, myeloperoxidase, lysozyme) and lymphocyte (5' nucleotidase) selective markers. Patients with acute but not those with quiescent colitis had striking increases of the neutrophil markers. Neither patient group with ulcerative colitis showed a change in the lymphocyte marker enzyme activity. Patients with Crohn's disease involving the rectum showed significant, but less marked, increases in the activity of the neutrophil markers that were found in active ulcerative colitis. Patients with Crohn's disease, not involving the rectum, showed normal or reduced levels of neutrophil markers. Patients with Crohn's disease, both those with and without rectal involvement, had increased activities of the lymphocyte selective marker. This distinguishes this inflammatory response from that of ulcerative colitis and provides further biochemical evidence of abnormalities in apparently uninvolved mucosa from Crohn's patients.