Decreased lysophospholipase and increased phospholipase A2 activity in ileal mucosa from patients with Crohn's disease.

Lysophospholipase (EC 3.1.1.5) and phospholipase A2 (EC 3.1.1.4) were determined in ileal mucosa from patients with Crohn's disease (CD) and non-inflammatory bowel diseases ( NIBD ). In addition, the activities of alkaline phosphatase, sucrase, maltase, and lactase were determined. The lysophospholipase activity, like that of alkaline phosphatase, sucrase and maltase, was decreased in affected areas of CD, whereas the phospholipase A2 activity was rather increased. Lysophospholipase and phospholipase A2 activities in apparently unaffected mucosa from CD patients were in between those in healthy mucosa from NIBD patients and those in affected mucosa from CD patients. These findings point to the possibility that the mucosal activity of lysophospholipase, like that of other brush border enzymes, is decreased in CD. This may render the mucosa less capable to handle lysolecithin, a potentially harmful agent formed in the intestine and known to induce inflammation in a number of experimental systems.