[Measurement of fecal chymotrypsin. Clinical and methodological aspects (author's transl)].

Fecal chymotrypsin activity was measured in 128 samples from 93 persons; the titrimetric procedure (Haverback) was used. Distribution of values in 67 normal persons was slanted positively and was approximatively logarithmical. The lower limit of normal was 120 microgram/g stool. Falsely normal results were obtained in 23% of 45 stool samples from 26 patients with pancreatic insufficiency. Falsely pathological results were found in 3,6% of cases. When chymotrypsin was measured photometrically (Imondi) and when the normal limit was assumed to be 50 microgram/g stool according to the literature, a diagnosis of pancreatic insufficiency was confirmed only in 30% of all patients, and 44% of the results were falsely pathological. Chymotrypsin was measured with both methods in 66 samples; correlation of results was unsatisfactory and definitely lower results were obtained with the photometrical procedure. No correlation could be found as well when chymotrypsin activities were measured in stool homogenates on the one hand, and in the supernatant of stools after centrifugation on the other hand, by the titrimetrical or by the photometrical method. Results obtained titrimetrically as well as photometrically after activation of chymotrypsin in pancreatic juice correlated well; the same was true for 2 photometric procedures tested (Imondi, Nagel). Stimulation of the exocrine pancreas with one Lundh meal did not result in any significant increase of fecal chymotrypsin activity in 12 persons tested.