Intra-epithelial T cells in coeliac disease

Histopathologic diagnosis of celiac disease in children without clinical evidence of malabsorption

Diverse clinical and pathologic experiences seem to have led to the idea that celiac disease is a spectrum in both categories. Conflicting results emerging from different reports have produced a large amount of confusion on the subject. This article discussed histopathology findings in 10 children with positive autoantibodies for celiac disease but without clinical evidence of malabsorption. The patients were evaluated following a detailed video-endoscopic study sampling the proximal (first and second) and distal (third and fourth) duodenal parts separately and processed apart. The procedure consistently revealed advanced villous atrophy in the proximal duodenal mucosa associated with mild to absent involvement of the distal segments. The data here presented favor the interpretation that (1) the presence of autoantibodies for celiac disease is always associated with mucosal damage, (2) mucosal damage in the absence of malabsorption is always evident in the proximal duodenum, and (3) the mucosal biopsy in search for the telltale damage needs to be done in separate samples of proximal and distal duodenal mucosa. This procedure may result in a better understanding of the dynamics of mucosal damage in celiac disease.

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

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 micromol/l +/- 0.27 versus 2.6 micromol/l +/- 0.54, P < 0002) and of the kynurenine/tryptophan ratio in supernatants of coeliac patients (11.5 micromol/l +/- 1.01 versus 6.5 micromol/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-gamma, interleukin-10 and transforming growth factor-beta. Our data suggest that a mechanism(s) dependent on tryptophan catabolism might regulate the immune responses in CD.

New advances in coeliac disease: serum and intestinal expression of HLA-G

Coeliac disease (CD) is a common autoimmune disorder characterized by an immune response to ingested gluten and has a strong HLA association with HLA-DQ2 and HLA-DQ8, but as human HLA-DQ risk factors do not explain the entire genetic susceptibility to gluten intolerance. Our aim was to investigate whether HLA-G, a gene located in the MHC class I region, and with important role in the induction of immunotolerance, may contribute to CD susceptibility. We demonstrated the expression of soluble HLA-G (sHLA-G) forms in intestinal biopsy and in serum of patients with CD. Indeed, all patients tested showed a positive expression of HLA-G in intestinal mucosa with different grade of immunoreaction. The serum levels of sHLA-G found in coeliac patients depend on the association with other diseases of autoimmune nature or genetics, and also depend on the transgressions in the diet with gluten ingested. The enhancer expression of sHLA-G in CD could be due as part of a mechanism to try restore the tolerance process towards oral antigens in a disease caused by loss of tolerance to dietary antigens and counteract the inflammation. In summary, in this paper, we demonstrate the association of CD with sHLA-G expression.