Serum phospholipase A2, amylase, lipase, and urinary amylase activities in relation to the severity of acute pancreatitis.

Objective: To compare serum phospholipase A2 activity with measurements of conventional enzymes as an indicator of the severity of acute pancreatitis.

Design: Prospective study.

Setting: University hospital, Finland.

Subjects: 80 Consecutive patients with acute pancreatitis.

Interventions: Serum and urine samples were taken daily for a week after admission.

Main outcome measures: Serum phospholipase A2, amylase, lipase, and urinary amylase activities.

Results: On admission, the serum amylase and lipase activities increased in parallel in all patients. However, the mean serum phospholipase A2 activity was three times higher in the patients with acute fulminant pancreatitis than in those with milder disease. The phospholipase A2 activity remained high during the course of the severe disease, whereas the other enzyme activities decreased appreciably during the first week. In contrast to the other enzyme activities that of serum phospholipase A2 correlated well with the severity of the acute pancreatitis. Heating at 60 degrees C for 45 minutes to inactivate the non-pancreatic thermolabile phospholipase A2 reduced the total serum phospholipase A2 activity more than the enzyme activity in the homogenates of pancreatic tissue, which suggests that extrapancreatic phospholipase A2 is present in serum. The receiver operating characteristic (ROC) curves confirmed the high sensitivity and specificity of serum phospholipase A2 activity with a mean (SEM) area under the curve up to 0.870 (0.062) compared with the other enzyme activities of which the highest area under the curve was 0.52 (0.089).

Conclusions: In contrast to amylase and lipase activities, measurement of serum phospholipase A2 activity is important in the assessment of the severity of acute pancreatitis so that optimal treatment may be given.