Serum amylase isozyme changes in chronic pancreatitis and their clinical significance.

The diagnostic usefulness of serum amylase isozyme measurement was investigated in 17 cases of definite chronic pancreatitis and 13 cases of suspected chronic pancreatitis, a total of 30 cases. Six types of serum isoamylase patterns were distinguished according to the character of the two main amylase activities at the fraction of fast-gamma globulin and pre-gamma globulin. The amylase activity of the fast-gamma fraction rises in acute exacerbation, and falls in cases of chronic calcifying pancreatitis and in cases with a marked decrease in pancreatic exocrine function. Especially, a fall in fast-gamma amylase activity excellently reflects a decrease in pancreatic enzyme production. The measurement of amylase activity at the fast-gamma fraction therefore appears to be a useful method for assessing pancreatic damage. The significance of a frequent rise in pre-gamma amylase activity in chronic pancreatitis remains unknown.