Clinical Information

Lipases are enzymes that hydrolyze glycerol esters of long-chain fatty acids and produce fatty acids and 1-acylglycerol. Bile salts and a cofactor, colipase, are required for full catalytic activity and greatest specificity. The pancreas is the primary source of serum lipase. Both lipase and colipase are synthesized in the pancreatic acinar cells and secreted by the pancreas in roughly equimolar amounts. Serum lipase is filtered and reabsorbed by the kidneys. Pancreatic injury results in increased serum lipase levels.

In pancreatitis, serum lipase becomes elevated at about the same time as serum amylase (in 4-8 hours). But serum lipase may rise to a greater extent and remain elevated much longer (7-10 days) than serum amylase. Elevations in serum lipase up to 50 times the upper reference values have been reported. The increase in serum lipase is not necessarily proportional to the severity of the attack and normalization is not necessarily a sign of resolution.

Both lipase and amylase should be very elevated in peritoneal fluid arising from the pancreas. Values in fluid of pancreatic origin should be at least several-fold higher than serum drawn at the same time, even in acute pancreatitis.