1 The Mallory Gastrointestinal Laboratory, Thorndike Memorial Laboratory, Second and Fourth (Harvard) Medical Services, and Department of Pediatrics, Boston City Hospital; the Department of Medicine, Harvard Medical School, and the Departments of Pediatrics and Pathology, Boston University School of Medicine
A 15-year-old boy with congenital lymphedema, ascites, hypoproteinemia, and a jejunal biopsy diagnostic of intestinal lymphangiectasia was studied. I131 albumin survival was evaluated by differential counting of the radioactivity in the lymphedematous and in the normal arm.
When a diet containing 150 gm of fat was fed daily, the I131 albumin half-life was 3.7 days in the normal arm and 22 days in the lymphedematous arm. Substitution of 75 gm MCT for 75 gm dietary fat increased the half-life in the normal arm to 5.1 days. Reduction of dietary fat to 25 gm per day further increased the half-life to 6.5 days in the normal arm. The I131 albumin half-life in the lymphedematous arm was not significantly affected by these dietary changes.
Although approximately 50% of the injected dose of labeled albumin had disappeared from the normal arm within 4 days, fecal and urinary losses accounted for only 15% of the injected dose. The high level of radioactivity remaining in the lymphedematous arm suggested significant "trapping" of the radioactive albumin. Albumin, cleared more slowly from the lymphedema because of inadequate lymphatic drainage, becomes unavailable to the metabolic pool. The observed rapid albumin half-life in intestinal lymphangiectasia is, thus, partly due to this "trapping" in addition to the known enteric losses of plasma proteins.
Submitted on September 16, 1966