Measurement of the 10,000-Molecular Weight Calcium-Binding Protein in Small-Intestinal Biopsy Specimens from Patients with Malabsorption Syndromes

Abstract

Calcium-binding protein (CaBP) (molecular weight, 10,000) was measured in small-intestinal biopsy specimens from 36 patients with malabsorption syndromes: short-bowel syndrome (n=13), untreated coeliac disease (n=4), coeliac disease in remission (n=7), patients with intestinal bypass owing to morbid obesity (n=5), and in patients with chronic diarrhoea of unknown cause (n=7). Twelve patients with no signs of malabsorption who had the irritable bowel syndrome were used as controls. Patients with small-bowel resections showed reduced concentrations of CaBP (p < 0.01) and low intestinal calcium absorption (p < 0.05). Small amounts of CaBP were found in intestinal specimens from patients with coeliac disease in remission (p < 0.01), and CaBP was almost undetectable in patients with a newly diagnosed coeliac disease and avillous jejunal biopsy findings (p < 0.001). Patients with chronic diarrhoea and patients with an intestinal bypass had CaBP concentrations comparable to those of the control group. A direct correlation was found between CaBP and the fractional calcium absorption in all patients (p < 0.05). CaBP may therefore be considered an indicator of the efficiency of the small intestine to absorb calcium.