Pancreatic stone protein. II. Implication in stone formation during the course of chronic calcifying pancreatitis.

Pancreatic stone protein, a novel protein isolated from pancreatic stones of patients suffering from chronic calcifying pancreatitis and secreted in normal human pancreatic juice, was measured by radial immunodiffusion in pure pancreatic juice. Patients with chronic calcifying pancreatitis of different etiologies had significantly lower levels of pancreatic stone protein when compared with other pancreatic diseases and controls. Pancreatic stone protein suppresses in vitro calcium carbonate precipitation and therefore stabilizes normally supersaturated pancreatic juice. The decreased pancreatic stone protein levels observed could be a key factor in the growth of calcium carbonate crystals and stone development during the course of chronic calcifying pancreatitis.