Serum lysozyme in Crohn's disease and ulcerative colitis.

Serum lysozyme (muramidase) was determined in 72 patients with Crohn's disease or ulcerative colitis. Serum lysozyme was elevated in both disease groups. The mean enzyme level was significantly higher in Crohn's disease than in ulcerative colitis, but there was a considerable overlapping between the groups, which makes serum lysozyme determination of dubious value in the differential diagnosis between Crohn's disease and ulcerative colitis. No correlation was found between the serum lysozyme concentration and the activity of the diseases.