[Lysozyme levels in chronic inflammatory bowel diseases (author's transl)]

Lysozyme concentrations in serum and urine were determined in 101 patients with Crohn's disease and 26 patients with ulcerative colitis. Lysozyme was assayed according to the lysoplate method of Osserman against a standard of humam lysozyme. The mean serum lysozyme concentrations (+/- S.E.M.) for each group were as follows: controls 8.4 +/- 1.8 (n equals 38), Crohn's disease 8.2+/-2.6 (n equals 101), ulcerative colitis 8.7+/-3.0 (n equals 26). No significant differences were found in serum lysozyme levels of the various groups of patients (2p is greater 0.05). There existed no correlation (r equals 0.12, n equals 129, p is greater than 0.05) with the activity of the disease. Serum lysozyme levels were significantly higher in patients affected by Crohn's disease of the small and the large bowel than in patients with involvement of the small intestine only and operated patients (2p is less than 0.05). The discriminative value of these findings with respect to the clinical course of such patients is limited because no significant differences are found between the levels of patients with Crohn's disease and controls. Neither in case of Crohn's disease nor ulcerative colitis were the mean urine lysozyme concentrations increased. These findings show that the determination of serum and urine lysozyme levels is unsuitable in respect of the differential diagnosis of inflammatory bowel disease as well as of the assessment of activity and extent of the disease.