Tryptophan metabolism and indoleamine 2,3‐dioxygenase expression in coeliac disease

• Published in: Clinical and experimental immunology Vol. 148; no. 3; pp. 419 - 424
• Main Authors: Torres, M. I., López‐Casado, M. A., Lorite, P., Ríos, A.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2007; Blackwell; Blackwell Science Inc
• Subjects: Biological and medical sciences; Biopsy; Celiac Disease - immunology; Celiac Disease - metabolism; Celiac Disease - pathology; Child; Child, Preschool; Chromatography, High Pressure Liquid - methods; coeliac disease; Crohn Disease - metabolism; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; IDO; Immunopathology; Indoleamine-Pyrrole 2,3,-Dioxygenase - metabolism; Infant; Interferon-gamma - metabolism; Interleukin-10 - metabolism; Intestinal Mucosa - immunology; Intestinal Mucosa - pathology; Intestine, Small - immunology; Intestine, Small - pathology; Kynurenine - blood; kynurenine metabolites; Male; Medical sciences; tolerance; Transforming Growth Factor beta - metabolism; Translational Studies; Tryptophan - blood; tryptophan metabolism; Immunopathology; tryptophan metabolism; Enzyme; Metabolite; Tolerance; Tryptophan; Coeliac disease; Metabolism; Immunology; Intestinal malabsorption; IDO; Aminoacid; Digestive diseases; Intestinal disease; Indoleamine-pyrrole 2,3-dioxygenase; Oxidoreductases; kynurenine metabolites
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2007.03365.x

Summary We have investigated the possible role of the metabolism of tryptophan and activity of the enzyme indoleamine 2,3‐dioxygenase (IDO) in the immune regulation of coeliac disease (CD). Serum concentrations of tryptophan and its metabolites kinurenines were determined by high performance liquid chromatography in 24 patients with CD, seven patients with Crohn's disease and five healthy patients. We detected an increase of kynurenine (4·2 µmol/l ± 0·27 versus 2·6 µmol/l ± 0·54, P < 0002) and of the kynurenine/tryptophan ratio in supernatants of coeliac patients (11·5 µmol/l ± 1·01 versus 6·5 µmol/l ± 1·57, P < 0005) in comparison with healthy patients, respectively, and we found no differences with Crohn's disease patients. Immunohistochemistry analysis of intestinal biopsies from CD patients showed an increased expression of IDO, interferon‐γ, interleukin‐10 and transforming growth factor‐β. Our data suggest that a mechanism(s) dependent on tryptophan catabolism might regulate the immune responses in CD.