Serum pancreatic stone protein in pancreatic diseases.

Serum pancreatic stone protein (PSP) was determined in sera of pancreatic and nonpancreatic diseases using enzyme immunoassay specific to human PSP to study the diagnostic and pathophysiological significance of PSP. Serum PSP in acute pancreatitis (mean +/- SD = 1075.4 +/- 2849.1 ng/mL, n = 33) was significantly higher than that in controls (78.6 +/- 31.8 ng/mL, n = 37, p < 0.01), chronic pancreatitis (156.8 +/- 82.8 ng/mL, n = 32, p < 0.05), and pancreatic cancer (148.468.8 ng/mL, n = 26, p < 0.05). No significant difference was found between noncalcified and calcified chronic pancreatitis. Serum PSP levels were significantly higher in chronic renal failure under hemodialysis (1796.0 +/- 1492.9 ng/mL) than in other diseases such as peptic ulcer, liver cirrhosis, gallstone, and diabetes mellitus. Low but significant correlation was obtained between serum PSP and serum immunoreactive trypsin (r = 0.22, p < 0.05). Increased serum PSP levels in acute pancreatitis and chronic renal failure suggest that serum PSP levels reflect reflex from pancreatic secretion, release from damaged pancreatic acinar cells, or retention in circulation, and can be useful for diagnosis of acute pancreatitis, but not chronic calcified pancreatitis.