Diagnosis of protein-losing gastroenteropathy by ¹¹¹In-transferrin scanning and fecal excretion test

Abstract

A total of twelve patients with gastroenteropathy were studied for possible protein loss. The underlying diseases were intestinal lymphangiectasia, ulcerative colitis and Crohn's disease in 2 patients each; and Ménétrier's disease, Cronkhite-Canada syndrome, postgastrectomy syndrome, severe atrophic gastritis, gastric cancer and gastroenteropathy of unknown origin in 1 patient each. The controls used in this study were four healthy volunteer and 9 patients with benign disease not accompanied by lesions in the digestive tract and protein loss, ¹¹¹In-transferrin (Tf) was prepared by incubating 2-3mCi of ¹¹¹In-chloride with 15-20ml of each patient's plasma in a sterilized vial at room temperature for 1 hour. After i.v. injection of ¹¹¹In-Tf, the patients were scanned at given intervals of time for 72 hours to localize protein loss. 72-hour fecal ¹¹¹In-Tf excretion was also measured. The following results were obtained: (1) ¹¹¹In-Tf was detected in the feces of all patients. The recovery rate in the patient group was 7.95±3.65%, which was significantly higher than 0.48± 0.26% in the control group (p<0.01). (2) However, ¹¹¹In-Tf scanning showed the site of protein loss only in 6 patients. Negative scan in six other patients was thought to be associated with extensive inflammation and severe diarrhea. (3) Five of the twelve patients were observed before and after treatment. A decrease in fecal ¹¹¹In-Tf excretion with clinical improvement was noted in the 5 patients after treatment. The site of protein loss could be demonstrated in 3 of the 5 patients before treatment. Its site in 1 of the 3 patients was the small intestine. However, accumulation of ¹¹¹In-Tf was found there in the 3 patients after treatment. The site of protein loss in one of three patients was the small intestine. In conclusion, ¹¹¹In-Tf scanning is particularly useful when the small intestine is involved, because surgery is contraindicated in this case. Fecal ¹¹¹In-Tf excretion test is mandatory when the site of protein loss cannot be imaged.