Immunoreactive phospholipase A2 in serum in acute pancreatitis and pancreatic cancer

Immunoreactive phospholipase A2 (EC 3.1.1.4) was measured by a new sensitive time-resolved fluoroimmunoassay in the serum of 58 healthy subjects and 103 patients with acute pancreatitis. Patients with acute pancreatitis were grouped according to the etiology and clinical severity of the disease. The mean phospholipase A2 concentration in the reference (healthy) group was 5.5 (SD 1.9) micrograms/L. In acute pancreatitis the mean phospholipase A2 concentration was increased on the first day after hospital admission in all groups, and returned to normal somewhat more slowly than did serum amylase, especially in the patients with severe alcoholic pancreatitis. In this latter group the mean concentration of serum phospholipase A2 on the first day was 42.6 (SD 29.5) micrograms/L. In patients with pancreatic cancer, serum phospholipase A2 was 29.2 (SD 21.3) micrograms/L. The phospholipase A2 and amylase values were closely associated in all groups. The clinical sensitivities were 90.9% for severe alcoholic pancreatitis and 87.5% for pancreatic cancer. Immunochemical determination of phospholipase A2 in serum provides fast and specific detection of injury to pancreatic acinar cells. In addition to the early diagnosis of acute pancreatitis, follow-up determinations of phospholipase A2 seem to be useful in differentiating between mild and severe forms of pancreatitis.