Elastase-1 vs trypsin, lipase and amylase serum levels in pancreatic diseases

Serum levels of elastase-1 were measured in 174 patients with pancreatic diseases and in 131 controls and were compared with the circulating levels of trypsin, lipase and amylase and with clinical data. In 48 patients with chronic pancreatitis serum enzyme levels were also compared with the pancreatic exocrine capacity. About 50% of the patients with chronic pancreatic disease showed increased levels of serum elastase, sometimes even in the face of long lasting pain-free periods, and/or of severe pancreatic impairment. On the contrary, serum trypsin and lipase were almost always either normal or below the normal range in the absence of painful relapses and/or in the presence of an impairment of the exocrine pancreatic function. A strict correlation was found between elastase-1 and trypsin (r = 0.778) and lipase (r = 0.834). However, controls and patients with chronic pancreatic diseases behaved differently, an increase in trypsin and in lipase levels being associated in the patients with chronic pancreatitis with an increase in elastase-1 values significantly larger than that observed in controls. These findings raise the hypothesis, at present unproven, that trypsin and lipase serum assays are more reliable indices of pancreatic exocrine function, whereas serum elastase-1 levels may indicate the presence of acute pancreatic episodes, even if subclinical, the importance of which, in the natural history of the disease, remains unknown.