Serum amylase isozymes in patients with chronic pancreatitis with hyperamylasemia.

In order to clarify the relationship between hyperamylasemia and clinical states in chronic pancreatitis, serum amylase isozymes were studied in 39 cases of chronic pancreatitis including 13 cases of alcoholic pancreatitis. Hyperamylasemia in chronic pancreatitis is generally due to high pancreatic type isoamylase (P-amylase) activity in acute exacerbation, sometimes accompanied by a transient elevation in salivary type isoamylase (S-amylase). On remission, however, hyperamylasemia due to high S-amylase activity has been found. These were cases of advanced alcoholic pancreatitis, which exhibited a characteristic pattern of low serum P-amylase and high serum S-amylase activities while the clearance ratio (Cam/Ccr) was normal despite high S-amylase activity. It should be noted that hyperamylasemia in chronic pancreatitis may be caused by high S-amylase activity in addition to high P-amylase activity, especially in alcoholic pancreatitis.