Serum phospholipase A₂ in intensive care patients with peritonitis, multiple injury, and necrotizing pancreatitis

To study the source and role of circulating phospholipase A₂ (PLA₂) catalytic activity we monitored the serum from patients with necrotizing pancreatitis (n=8), diffuse peritonitis (n=6), and multiple injuries (n=11). Immunoreactive PLA₂ serum protein concentration was analysed using a fluoroimmunoassay based on an antibody against human pancreatic PLA₂. Serum PLA₂ catalytic activity was analysed using a radiochemical method based on a substrate with tritiated palmitic acid in beta position. In necrotizing pancreatitis immunoreactive PLA₂ and PLA₂ catalytic activity both increased. Obviously, in necrotizing pancreatitis the major part of serum catalytic activity stems from the pancreas. In patients with diffuse peritonitis and multiple injuries, as a rule, immunoreactive phospholipase A₂ serum concentration appears to be within the normal range. In contrast, in these patients we demonstrated high serum catalytic PLA₂ activity comparable to that in necrotizing pancreatitis. The source of catalytic PLA₂ activity in peritonitis and multiple injuries seems not to be the pancreas. There was a correlation between pulmonary insufficiency and serum PLA₂ catalytic activity in patients with necrotizing pancreatitis, peritonitis, and multiple injuries.