[The diagnostic value of In-111 transferrin imaging in protein-losing gastroenteropathy]

The diagnostic value of In-111 transferrin abdominal imaging was studied in 17 patients with clinical suspicion of protein-losing gastroenteropathy, compared to that of alpha-1-antitrypsin fecal clearance test. The presence or absence of gastrointestinal protein-loss was finally decided based on the result of alpha-1-antitrypsin fecal clearance test (normal range, less than 13 ml/day) or of protein content measurement on the gastric juice (normal range, less than 71 mg/dl). In-111 transferrin was labeled in vitro. After intravenous administration, serial anterior abdominal images were obtained. All seven patients with a value equal to or more than 20 ml/day on the alpha-1-antitrypsin clearance test and two out of ten patients with a value less than 20 ml/day showed definite intestinal activity demonstrating protein-loss, and the loss-site was estimated by observing the movement of radiotracer within the bowel lumen. The patients with severe protein-loss showed the intestinal activity on the early image. In the patients with milder protein-loss, on the other hand, the activity was noted on the later image. All two patients with positive In-111 transferrin imaging and negative alpha-1-antitrypsin test were associated with protein-losing gastropathy, where a value of alpha-1-antitrypsin clearance was not increased because of denatured alpha-1-antitrypsin by acidic gastric juice and pepsin. These results suggest that In-111 transferrin abdominal imaging can be more useful for the diagnosis of protein-losing gastroenteropathy, because of its capabilities to evaluate the patients with gastropathy as well as to estimate the loss-site.