Duodenal Secretion and Fecal Excretion of Pancreatic Elastase-1 in Healthy Humans and Patients with Chronic Pancreatitis

Abstract

Fecal elastase-1 is a candidate for a sensitive noninvasive test detecting 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 o f a mixed liquid meal at 2.5 kcalimin for 150 min), (b) to compare the diagnostic accuracy of fecal elastase-1 and fecal chymotrypsin, and (c) to characterize the cyclical pattern of postprandial pancreatic secretion in healthy subjects and patients with chronic pancreatitis. Based on their enzyme responses to duodenal meal perfusion and imaging procedures. 12 patients were classified as having normal pancreatic function and 11 patients as having chronic pancreatitis. Duodenal enzyme outputs of elastase-1 were markedly lowered in chronic pancreatitis ( p < 0.0001) and correlated well with the outputs of the other four enzymes ( r > 0.71, p < 0.00001). Fecal Concentrations of elastase-1 were also clearly reduced i n chronic pancreatitis ( p < 0.0001). Fecal chymotrypsin was less strongly associated with duodenal enzyme outputs ( r = 0.33 to r = 0.5871, whereas fecal elastase-! 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 pancreatitis amounted to 0.64 and 0.95 for fecal elastase-1 and 0.27 and 0.95 for fecal chymotrypsin. respectively. I n the postprandial state, peaks of enzyme secretion occurred at a frequency of about ! peak1150 min. The amplitude but not the frequency of secretory peaks was markedly reduced in chronic pancreatitis ( p < 0.01).We conclude that fecal elastase-1 clearly exceeds the sensitivity of fecal chymotrypsin in the diagnosis of chronic pancreatitis but does not reliably detect all cases with mild to moderate disease. The pattern of postprandial pancreatic secretion is cyclical. even with minimal secretory outputs in chronic pancreatitis.

Low Fecal Elastase: Potentially Related to Transient Small Bowel Damage Resulting from Enteric Pathogens

“…The sensitivity and specificity of FE is greater than 90% for moderate and severe exocrine pancreatic insufficiency, clearly superior to fecal chymotrypsin (1)(2)(3)6,8,9,12,17). It is also simple, relatively cheap, stable (5), with very low intraindividual variation (1,2,18).…”

“…It is also simple, relatively cheap, stable (5), with very low intraindividual variation (1,2,18). A significant correlation exists between FE and stimulated duodenal volume, and the bicarbonate, amylase, lipase, and trypsin concentration of duodenal aspirates (1,2,6,9). In normal condi- tions, both neural (entero-pancreatic, cholinergic, vagovagal reflexes) and hormonal (cholecystokinin) pathways mediate the pancreatic enzyme response to intestinal stimulants.…”

“…Pancreatic elastase is not degraded during intestinal transit and thereby FE reflects exocrine pancreatic function (1,2). Several reports show its utility in cystic fibrosis with pancreatic involvement (3)(4)(5)(6)(7) and chronic pancreatitis in adults (8,9). In celiac disease its level seems inversely related to the degree of enteropathy with restoration of normal value when healing of mucosal damage occurs (10).…”

Comparison of Fecal Elastase 1 for Exocrine Pancreatic Insufficiency Evaluation Between Ex-Alcoholics and Chronic Pancreatitis Patients

“…Fecal elastase 1 had a sensitivity of 16.7%-63% for mild, 12.5%-100% for moderate and 72.2%-100% for severe exocrine pancreatic insufficiency. It had a specificity of 90%-95% with a cutoff value of 200 µg/g, and with this cutoff value, it was less reliable for the detection of some cases of mild and moderate pancreatitis (9,12,15,16) . The sensitivities of fecal elastase 1 for the detection of calcifying pancreatitis (76.5%) and autoimmune pancreatitis (71.4%) were higher than for definite chronic pancreatitis (60%), confirming that it is a reproducible marker for severe pancreatic insufficiency (16) .…”

Diagnosis of pancreatic exocrine insufficiency in chronic pancreatitis

“…The fecal excretion of pancreatic enzymes correlates with duodenal enzyme secretion (19). However, pancreatic enzymes are inactivated to different degrees during gastrointestinal transit.…”