DUODENAL SECRETION AND FECAL EXCRETION OF PANCREATIC ELASTASE-1 IN HEALTHY HUMANS AND PATIENTS WITH CHRONIC-PANCREATITIS

Fecal elastase-1 is a candidate for a sensitive noninvasive test detec ting chronic pancreatitis. This prospective study enrolled 10 healthy male controls and 23 patients referred for tube testing of pancreatic function. It was designed (a) to correlate duodenal outputs and fecal concentrations of elastase-1 with duodenal outputs of amylase, lipase, trypsin, and chymotrypsin in the fed state (duodenal perfusion of a m ixed liquid meal at 2.5 kcal/min for 150 min), (b) to compare the diag nostic accuracy of fecal elastase-1 and fecal chymotrypsin, and (c) to characterize the cyclical pattern of postprandial pancreatic secretio n in healthy subjects and patients with chronic pancreatitis. Based on their enzyme responses to duodenal meal perfusion and imaging procedu res, 12 patients were classified as having normal pancreatic function and 11 patients as having chronic pancreatitis. Duodenal enzyme output s of elastase-1 were markedly lowered in chronic pancreatitis (p < 0.0 001) and correlated well with the outputs of the other four enzymes (r > 0.71, p < 0.00001). Fecal concentrations of elastase-1 were also cl early reduced in chronic pancreatitis (p < 0.0001). Fecal chymotrypsin was less strongly associated with duodenal enzyme outputs (r = 0.33 t o r = 0.587), whereas fecal elastase-1 correlated more precisely with the duodenal outputs of all five enzymes (r = 0.637 to r = 0.830, p < 0.00001). Sensitivity and specificity in the detection of chronic panc reatitis amounted to 0.64 and 0.95 for fecal elastase-1 and 0.27 and 0 .95 for fecal chymotrypsin, respectively. In the postprandial state, p eaks of enzyme secretion occurred at a frequency of about 1 peak/150 m in. The amplitude but not the frequency of secretory peaks was markedl y reduced in chronic pancreatitis (p < 0.01). We conclude that fecal e lastase-1 clearly exceeds the sensitivity of fecal chymotrypsin in the diagnosis of chronic pancreatitis but does not reliably detect all ca ses with mild to moderate disease. The pattern of postprandial pancrea tic secretion is cyclical, even with minimal secretory outputs in chro nic pancreatitis.