Serum Phospholipases A2 in Patients Undergoing Panproctocolectomy Because of Severe Ulcerative Colitis

Summary: A major role has been proposed for group II phospholipase A2 in the pathogenesis of local and generalised inflammatory reactions. Elevated catalytic activity and mass concentrations of this enzyme have been found in serum and tissue samples of the colon in patients with active ulcerative colitis. The cellular source(s) of group II phospholipase Az in the blood circulation is (are) unknown. In the current prospective study, we investigated the mass concentration of group II phospholipase AI and the catalytic activity concentration of phospholipase AI in serial serum samples of 15 consecutive patients who underwent a standard panproctocolectomy operation for severe ulcerative colitis. Both the catalytic activity concentrations of phospholipase A2 and the mass concentrations of group II phospholipase AI increased rapidly in serum samples to maximum values on the first postoperative day and then decreased (p = 0.002 and p < 0.001, respectively) in patients who recovered uneventfully. Three patients had postoperative complications that further increased the enzyme concentrations at the time of respective complications. The pattern of group II phospholipase Az mass concentration profiles was similar to the profiles of C-reactive protein. The results show that the removal of the large bowel does not eliminate the potential to secrete group II phospholipase AZ into the blood circulation in these patients. Secretion of group II phospholipase A2 into the circulation after surgery seems to be a normal host response to a major abdominal operation and postoperative complications. Consequently, we conclude that the large bowel is not an important source of group II phospholipase AZ in sera of patients with ulcerative colitis. The results also support the assumptions that the catalytic activity of phospholipase A2 in serum is attributable to group II phospholipase A2 and that this enzyme is an acute phase protein.