Serum lysozyme in inflammatory bowel and coeliac disease.

Serum lysozyme levels were determined by a turbidometric method using egg white lysozyme as standard in 100 patients with Crohn's disease, 86 with ulcerative colitis, 31 with coeliac disease, and in 38 normal control subjects. Though the levels in Crohn's disease were significantly higher than those in ulcerative colitis and in coeliac disease, there was marked overlap between the disorders and control subjects, and so they were of no value in differential diagnosis. There was some evidence that serum lysozyme levels reflected disease activity in Crohn's disease but not in ulcerative colitis.