Usefulness of determination of serum immunoreactive pancreatic phospholipase A2 content for early identification of severe acute pancreatitis.

To investigate the correlation between the initial levels of serum pancreatic enzymes and the severity of acute pancreatitis, serum amylase activity, immunoreactive trypsin content, phospholipase A2 activity and immunoreactive pancreatic phospholipase A2 content were comparatively measured in 22 patients with acute pancreatitis. Serum immunoreactive pancreatic phospholipase A2 content and phospholipase A2 activity in the severe group were significantly elevated as compared with those in the group of moderate pancreatitis on the first day of onset. The elevation of the initial immunoreactive phospholipase A2 content in the severe group was far greater than that of amylase activity, trypsin content and phospholipase A2 activity. The difference between immunoreactive phospholipase A2 content and phospholipase A2 activity was, in part, due to the presence of prophospholipase A2 in severe acute pancreatitis sera, but the phospholipase A2 content measured by radioimmunoassay was still about 5 times higher than that calculated from fully activated phospholipase A2 activity by trypsin.