Plasma alpha 2-macroglobulin-trypsin complexlike substance (MTLS) in pancreatic disease.

alpha 2-macroglobulin-trypsin complexlike substance (MTLS) was determined in plasma of pancreatic and nonpancreatic diseases using a two-step enzyme immunoassay to study the diagnostic and pathophysiological significance of MTLS. Plasma levels of MTLS in acute pancreatitis (mean +/- SD = 265.6 +/- 346.2 ng/ ml, n = 9), calcified chronic pancreatitis (128.6 +/- 257.4, n = 13), and noncalcified chronic pancreatitis (13.5 +/- 12.5, n = 10) were significantly higher than that in controls (3.6 +/- 1.8, n = 81). In other diseases such as gastric cancer, hepatoma, diabetes mellitus, and gallstones, MTLS values were not different from those of control. Plasma MTLS values showed low correlation with serum trypsin, elastase 1, pancreatic amylase, lipase, and pancreatic secretory trypsin inhibitor (PSTI). The elevation of plasma MTLS values in acute pancreatitis suggests that plasma MTLS levels reflect that protease is inappropriately activated in pancreatic acinar cell and released into the circulation and that the determination of MTLS can be useful for diagnosis and pathophysiology of acute pancreatitis and chronic pancreatitis.