Serum immunoreactive trypsin response to secretin injection in patients with chronic pancreatitis

Serum immunoreactive trypsin response to secretin injection (75 clinical units iv over a 2-min period) was studied in patients with chronic pancreatitis and in control subjects. Secretin stimulation caused a slight but significant increase of basal serum immunoreactive trypsin concentration in normal subjects and a marked increase in chronic pancreatitis patients with mild to moderate insufficiency. In patients with severe insufficiency and steatorrhea it had very little effect. The integrated immunoreactive trypsin response to secretin injection in patients with mild to moderate insufficiency was significantly higher compared to controls and to patients with severe insufficiency. In the latter patients it was significantly lower than in controls. A markedly elevated response of serum immunoreactive trypsin to secretin administration seems to differentiate chronic pancreatitis patients with mild to moderate insufficiency from those with severe insufficiency and from controls.