Fecal Excretion of Radiolabeled (⁵¹CrCl₃) Proteins in Patients with Crohn's Disease

Abstract

Intestinal leakage of plasma proteins was studied in 69 patients with Crohn's disease. In vivo labeling of plasma proteins was performed by intravenous injection of trace amounts of ^5lCrCl₃. Complete fecal collection was done for 5 days, carefully avoiding contamination with urine. The daily fecal radioactivity was measured in a whole-body counter and expressed as a percentage of given dose. In patients with a classic localization of the disease the mean fecal excretion of radiolabeled proteins was 2.8% (range, 0.8-5.5%). The excretion was significantly higher in patients with extensive ileojejunal involvement (8.8%; 4.3-14.0%) and in patients with a total colitis (5.5%; 2.0-8.2%) but not different from that in patients with prestomal recurrent ileal disease (3.5%; 1.6-5.3%). A close correlation was found between fecal excretion of ⁵¹Cr and extent of the small-intestinal disease as measured at laparotomy (r — 0.86, p < 0.001). A highly significant inverse relationship was also demonstrated between fecal protein excretion and serum albumin concentration in patients without septic complications of the disease (r = -0.57, p< 0.001). A pre-existing septic complication made the patients hypoalbuminemic despite limited intestinal loss of protein. It is concluded that estimation of intestinal protein loss is a sensitive and simple test for assessment of the extent of the small-intestinal involvement in patients with Crohn's disease. The test may be of value in patients with unclear radiologic findings and in patients with hypoalbuminemia of unknown cause.

Key Words:

• Albumin
• Crohn's disease
• protein-losing enteropathy