Enteric protein loss in various gastrointestinal diseases determined by intestinal alpha 1-antitrypsin clearance.

Intestinal protein loss was measured by means of faecal alpha 1-antitrypsin clearance (alpha 1 ATC) in patients with various gastrointestinal diseases. In healthy controls and in patients with various gastrointestinal diseases there is a remarkable intraindividual fluctuation of the faecal protein loss from day to day. Alpha 1 AT clearance calculated from a three-day stool collection is usually sufficient to indicate enteric protein loss in Crohn's disease, ulcerative colitis, celiac sprue, and Whipple's disease. However, in two patients with intermittent diarrhea coinciding with edema and hypalbuminemia excessive enteric protein loss was observed on one day during a two week stool sampling period only. In one of these patients suction biopsies showed histologically intestinal lymphangiectasia of a 10 cm segment of the upper jejunum. The alpha 1 ATC is a suitable and cheap method to determine enteric protein loss without the use of radioactive tracers and therefore can be used in clinics without departments of nuclear medicine. In contrast to the conventional Gordon test the use of the endogenous marker alpha 1 AT facilitates the determination of faecal protein loss over long time periods, which might be of value in the diagnosis of intermittent occurring enteric protein loss. Furthermore, the endogenous marker alpha 1 AT is of use in following the course of illness and in monitoring the efficacy of therapy in patients with enteric protein loss.