Pancreatic and synovial type phospholipases A2 in serum samples from patients with severe acute pancreatitis.

Phospholipase A2 (PLA2) is the rate limiting enzyme in the formation of prostaglandins and probably plays a key part in the pathology of various inflammatory diseases. In acute pancreatitis, the catalytic activity of PLA2 in serum correlates with the severity of the disease. The cellular source of the catalytically active PLA2 in serum of patients suffering from acute pancreatitis and other diseases is unknown. Immunoassays for the measurement of pancreatic group I PLA2 and nonpancreatic synovial type group II PLA2 have recently been developed and the present study investigated the presence of group I and group II PLA2s in serum samples from 36 patients with severe acute pancreatitis. The catalytic activity of PLA2 showed a highly significant correlation with the concentration of synovial type PLA2 (r = 0.939, p = 0.001) but not with the concentration of pancreatic PLA2 (r = 0.067, p = 0.698). The results suggest that pancreatic PLA2 circulates mostly as inactive enzyme in patients with acute pancreatitis whereas synovial type PLA2 is responsible for the increased catalytic activity of the enzyme and thus might be associated with the pathophysiology of the disease.