Protein-losing enteropathy detected by 99mTc-labeled human serum albumin abdominal scintigraphy.

99mTc-labeled human serum albumin (HSA) abdominal imaging is a new way of demonstrating gastrointestinal protein loss. We present two children with hypoalbuminemia of obscure etiology in whom albumin loss was localized in the gastrointestinal tract with 99mTc-HSA scintigraphy and the loss correlated with abnormal fecal alpha 1-antitrypsin excretion. In the absence of gastrointestinal blood loss or contamination of the 99mTc-HSA with free pertechnetate, significant activity accumulating in the gastrointestinal tract and moving with its contents is thought to represent 99mTc-HSA leakage into bowel lumen. Abdominal imaging with 99mTc-HSA has a low radiation burden to the patient and is readily available, relatively inexpensive, and easily performed. It can be used as a screening test for the detection of protein-losing enteropathy. It also offers the potential of being able to localize the site of protein loss visually within the gastrointestinal tract.