Clinical usefulness of serum phospholipase a₂determination in patients with pancreatic diseases

A new kit for radioimmunoassay of serum phospholipase A₂(PLA₂) with monoclonal antibody (S-0932, Shionogi, Osaka, Japan) was used to examine PLA₂levels in patients with various diseases. Patients with acute pancreatitis showed significantly increased serum PLA₂levels. In patients with chronic pancreatitis, significant correlations were observed between the levels of factors evaluated by the secretin test and serum PLA₂levels. In patients with pancreatic cancer, serum PLA₂levels varied with disease severity. Serum PLA₂concentrations were within the normal range in patients with other malignant tumors, diabetes mellitus, and chronic liver diseases but were increased in patients with chronic renal failure. S-Sepharose column analysis of sera showed a small peak of pro-PLA₂and a large peak of PLA₂in sera from patients with severe acute pancreatitis, but a large peak of pro-PLA₂in healthy controls and patients with other diseases. On G-100 gel filtration, high-molecular-weight PLA₂immunoreactivity was detected in sera of patients with chronic renal failure, whereas a single peak of PLA₂immunoreactivity coinciding with that of standard PLA₂was detected in sera of patients with acute pancreatitis. These results suggest that (a) measurement of serum PLA₂is clinically useful for diagnosis and monitoring of pancreatitis, (b) active PLA₂in the circulation is dominant in severe acute pancreatitis, and (c) the kidney may be the main site of PLA₂degradation or excretion.