Characterisation of tissue transglutaminase-reactive T cells from patients with coeliac disease and healthy controls.

Previous studies have shown evidence for T lymphocytes specific for tissue transglutaminase (tTG) in the periphery of coeliac disease (CD) patients. These cells could play a role in disease pathogenesis and may be involved in providing help for the production of anti-tTG autoantibodies. The objective of this study was to further investigate the presence of tTG-specific T cells in patients with treated and untreated CD, and normal controls. Positive proliferative responses to three different commercial tTG antigens were detected in all groups tested, occurring more frequently and at higher levels in untreated CD patients. The addition of antibodies to HLA-DQ and HLA-DR caused a significant reduction in the proliferative response to tTG. T cell lines specific for tTG and composed predominantly of CD4-positive T cells were generated from responsive CD and control individuals, and were found to produce large amounts of interferon-γ, as well as interleukins 10, 17A, and 21.

The absence of a mucosal lesion on standard histological examination does not exclude diagnosis of celiac disease.

Some patients with undiagnosed celiac disease have minor mucosal lesions that may not be apparent during routine histological analysis. Twenty-five such patients of our institution were discharged to their primary-care physicians despite having positive endomysial antibody serology. To re-evaluate diagnosis for these patients, immunohistological staining with antibodies to CD2, CD3, CD7, CD8, CD69, and Ki67 was conducted on original biopsies from twenty patients. Clinical, serological, and histological investigations were offered to all fourteen patients who attended for review. We observed a significantly greater (P < 0.0001) numbers of intraepithelial lymphocytes and Ki67-positive enterocytes in sections from these twenty patients than for normal controls. Of the fourteen patients who attended for further review, firm diagnosis of celiac disease was made for seven patients and diagnosis was likely for another two. Our study clearly revealed that over-reliance on standard histological findings results in failure to diagnose celiac disease.

Increased protein expression of matrix metalloproteinases -1, -3, and -9 and TIMP-1 in patients with gluten-sensitive enteropathy.

Gluten-sensitive enteropathy is characterized by small intestinal damage. The pathogenic mechanisms involved are not precisely understood. There is recent interest in the possibility that matrix metalloproteinases might play a pathogenic role. Using immunohistochemistry technique, we examined the protein expression of matrix metalloproteinases-1, -3, and -9 and the tissue inhibitor metalloproteinase-1 in duodenal biopsies from 30 patients with celiac disease and dermatitis herpetiformis. We demonstrated that the percentage of cells expressing these enzymes and their inhibitor in all patients was significantly greater than in the normal controls (P < 0.0001). This was evident even in patients with a minimal lesion but was most marked in patients with severe damage, mirroring the degree of inflammation in the small intestinal tissue. The increased expression of these enzymes and their inhibitor in the duodenal mucosa of patients with gluten-sensitive enteropathy suggests a role for these enzymes in the tissue remodeling which is a feature of these disorders.