Fecal Chymotroypsin: a Study on Its Diagnostic Value by Comparison with the Secretin-Cholecystokinin Test

Abstract

Fecal chymotrypsin (CT) activities were determined in 149 randomly collected fecal specimens of 80 patients in whom the pancreatic function had been tested by a secretin-cholecystokinin test. There was a significant correlation between fecal CT activities and outputs of trypsin (r = 0.3451, p < 0.01) and amylase (r = 0.3285, p < 0.01) in duodenal juice. Fecal CT activities were normal in all patients who – based upon enzyme outputs in duodenal juice after stimulation with secretin and CCK/PZ – were classified as ‘borderline cases’, in most patients with ‘Ιow-normal’ pancreatic function, and in a significant number of patients with established insufficiency of exocrine pancreas. On the other hand, fecal CT activities were abnormal in patients with severely impaired output of trypsin in duodenal juice, and only 7% of the fecal specimens from patients with established normal function of exocrine pancreas had abnormal low CT activities. It is concluded that the sensitivity of the fecal enzyme method is rather low as compared to the secretin-cholecystokinin test, but that fecal CT determinations give valuable diagnostic information in patients with more pronounced insufficiency of the exocrine pancreas.

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

“…In a meta-analysis, fecal chymotrypsin achieved average sensitivities of 49% in mild chronic pancreatitis and 85% in severe disease (19). Whereas the occurrence of false-normal values in mild degrees of functional impairment is clearly reproducible in several studies (3,(25)(26)(27), fecal chymotrypsin may also be normal in patients with moderate or severe disease (8). In the present study, enrolling predominantly patients with chronic pancreatitis and no or mild steatorrhea, <15 glday, fecal chymotrypsin achieved a sensitivity of only 0.27.…”

Diagnostic Value of the Fecal Chymotrypsin Test in Pancreatic Insufficiency, Particularly Chronic Pancreatitis: Correlation with the Pancreozymin-Secretin Test, Fecal Fat Excretion and Final Clinical Diagnosis

“…1). In the present study, pancreatic hypofunction was classified based on bicarbonate and enzyme secretion data, which renders a comparison with the results of other investigations, using mainly enzyme secretion data (8,14), difficult. Our data, however, confirm a gradual increase in false-normal FCT values parallel to the de creasing severity of pancreatic hypofunction (table II).…”

“…The interpretation of the reported data (8,14) is difficult mainly for three reasons: (a) the small number of patients; (b) the un certainty regarding the interpretation of bor derline findings of the pancreozymin-secretin test (PST), and (c) the lack of clinical data for the classification of cases with proved -creatic hypo function. The problem has, therefore, been reevaluated by analyzing in our material of the last 16 years the relation ship of (a) PST and FCT in patients with proved pancreatic hypofunction; (b) FCT and fecal fat excretion in patients with CP, and (c) pancreatic hypofunction and final clinical diagnosis based upon long-term follow-up studies.…”

Guidelines for the investigation of chronic diarrhoea, 2nd edition

“…There has been considerable controversy over the merits of stool measurement of chymotrypsin. [138][139][140] Many of the initial problems related to the assay have subsequently been refined and it has been used with some success in the diagnosis of pancreatic disease in cystic fibrosis and non-specific chronic pancreatitis. 141 142 Stool chymotrypsin has also been compared with the N-benzoyl-Ltyrosyl-p-aminobenzoic acid (NBTP-PABA) test and the secretin-caerulin test.…”