Immunohistochemical identification of lysozyme in intestinal lesions in ulcerative colitis and Crohn's disease.

Lysozyme (LZM) was identified in ulcerative colitis in granulocytes, monocytes, and macrophages of the intestinal lamina propria. In contrast with findings in normal colon or rectum, in ulcerative colitis LZM was also detected in some mucosal crypt cells and metaplastic Paneth cells. In both ulcerative colitis and Crohn's disease LZM was present in inflammatory cells of crypt abscesses. In Crohn's disease intense LZM staining was seen in epitheloid cell granulomas. The present observations permit one explanation for the raised concentration of serum-LZM in patients with ulcerative colitis and Crohn's disease.