Increase in T-cell subsets of oral mucosa: a late immune response in patients with treated coeliac disease?

BACKGROUND AND AIMS: In coeliac disease, the gut involvement is gluten-dependent. Following the introduction of a gluten-free diet, inflammatory cell infiltration decreases in the small intestinal mucosa. Our hypothesis was that the oral mucosa might mirror the changes found in coeliac disease similarly to the mucosa of the small intestine. Thus, the number of inflammatory cells in the oral mucosa would decrease in patients with coeliac disease on a gluten-free diet. METHODS: The distribution CD45RO+ and CD3(+) T cells, T-cell subpopulations (CD4(+), CD8(+), T-cell receptor (TCR)alpha beta+ and TCR gamma delta+ cells) and HLA DR expression were studied in the buccal mucosa of 15 untreated and 44 gluten-free diet treated coeliac disease patients, and of 19 controls. All 15 patients with untreated coeliac disease were immunglobulin (Ig)A endomysial antibody positive and all 44 patients on gluten-free diet except one were endomysial antibody negative, as were all control subjects. RESULTS: Untreated coeliac disease patients did not differ from controls in the densities of CD45RO+ cells, CD3(+) cells or of T-cell subsets. In contrast, in treated coeliac disease patients, a significant increase in the numbers of mast cells, CD3(+) and CD4(+) lymphocytes was found in the lamina propria of oral mucosa as compared with patients with untreated coeliac disease and controls. The increase in CD3(+) T cells was in part owing to an increase in lymphocytes expressing no TCR. No differences were found in the expression of human leucocyte antigen (HLA) DR in the epithelium or in the lamina propria in the patient groups studied or in the controls. In treated coeliac disease patients only a few TCR gamma delta+ T cells were found intraepithelially and in the lamina propria, but these cells were not detected in the lamina propria of oral mucosa of patients with untreated coeliac disease or in the controls. CONCLUSIONS: The infiltration of T cells into oral mucosa was increased in treated coeliac disease patients in spite of adherence to a gluten-free diet. Because the CD3(+) T cell count was higher than those of the TCR alpha beta+ and TCR gamma delta+ T cells, there must be other cells involved, probably natural killer (NK) cells. The increase in T-cell subsets in the treated coeliac disease patients seems not to result from poor dietary compliance, but might occur as a late immune response in coeliac disease and reflect chronic immunologic stimulation followed by regeneration of memory T cells.

Local challenge on oral mucosa with an alpha-gliadin related synthetic peptide in patients with celiac disease.

OBJECTIVE: Gluten-derived peptides (e.g., amino-acids 31-49 of alpha-gliadin) have been shown to cause changes typical of celiac disease in the gut. Gluten-derived peptides have mostly been used in in vitro studies. The easiest access to the gastrointestinal system may be the mouth. In the present study we were interested to see whether a synthetic peptide corresponding to amino-acids 31-49 of alpha-gliadin could induce inflammatory changes in the oral mucosa after a local challenge in celiac disease patients. METHODS: The challenge was made by injecting the peptide solution at a concentration of 10 microg/ml submucosally into the oral mucosa of 10 celiac disease patients after a gluten-free diet (GFD) and 12 healthy control subjects. B and CD45RO+ T cells, mast cells, CD3+, CD4+, CD8+ lymphocytes, and alphabeta and gammadelta T-cell receptor-bearing (TcR alphabeta, TcR gammadelta) lymphocytes were counted and HLA DR expression was determined. The expression of CD25 and Ki-67 antigen was also examined. RESULTS: The peptide significantly increased the total number of T cells in the lamina propria of the celiac disease patients. The expression of T-cell activation marker CD25 (IL-2 receptor), but not that of cell proliferation marker Ki-67, was also significantly increased in the lamina propria after peptide challenge. Such a reaction was not observed in the controls. The numbers of CD3+ and CD4+ T cells in the lamina propria were also increased in celiac disease patients after the challenge. The count of TcR gammadelta+ cells was very small in the oral mucosa in celiac disease and showed no increase when the oral mucosa was challenged with the peptide. The expression of HLA DR staining was enhanced after the submucosal peptide challenge in celiac disease; however, the difference was not statistically significant. CONCLUSIONS: The results show that in the celiac disease patients after the peptide challenge the oral mucosal lamina propria responds with a nonproliferative increase of lymphocytes. Thus, submucosal challenge with the peptide 31-49 can be used as an aid in the diagnosis of celiac disease. However, further studies with optimized methodology, including various concentrations of the peptide, adjuvants, other peptides, etc., are warranted, especially because the oral mucosa provides the easiest access to an in vivo peptide challenge in celiac disease.

Local challenge of oral mucosa with gliadin in patients with coeliac disease.

In coeliac disease, gluten-containing diet challenges over many years are sometimes required for diagnosis, especially if the initial diagnosis was equivocal. The rectal gluten challenge has been proposed to simplify coeliac disease diagnosis. We were interested in studying whether the oral mucosa could be used for local challenge with gliadin as an aid in finalizing the diagnosis of coeliac disease. The study groups consisted of 37 treated coeliac disease patients and 10 controls. The challenges on the oral mucosa were performed either supramucosally with gliadin powder (coeliac disease patients) or by submucosal injection of dissolved gliadin (10 microg/ml) (coeliac disease patients and controls). A control challenge with submucosal gliadin solvent was made in the coeliac disease patients. B and T cells, mast cells and T cell subsets were counted and HLA-DR expression was determined. Biopsies were taken from each provoked area 24 h post-challenge. A significant increase in the number of CD4+ lymphocytes in the lamina propria (observed in 27/37 patients), but a decrease in the number of mast cells was observed in treated coeliac disease patients after submucosal challenge with gliadin. Following supramucosal challenge with gliadin the counts of intraepithelial CD4+ (in 25/37 patients) and CD8+ T cells (in 27/37 patients) increased significantly and the number of CD4+ T cells in the lamina propria was also significantly increased. Control subjects were tested by submucosal gliadin challenge and no significant changes in the number of cells were observed. HLA-DR expression did not show increased positivity in coeliac disease patients on submucosal challenge. For the first time the oral mucosa has been used for immunological testing and shown to react to gliadin challenge in coeliac disease patients. Recruitment of T cells upon submucosal gliadin challenge occurred towards the lamina propria, whereas it occurred towards the epithelium in supramucosal gliadin challenge. The numbers of T cells increased in the lamina propria after submucosal challenge. The results suggest that local oral challenge with gliadin may be used as a diagnostic method in coeliac disease; however, further studies in untreated coeliac disease patients are needed to evaluate the usefulness of this method.

Changes in whole saliva in patients with coeliac disease.

Many systemic diseases impair salivary flow rate and composition and therefore incite oral pathological processes. This study analyses the composition of whole saliva in patients with diagnosed coeliac disease (CD) and in healthy controls, and monitors possible changes in saliva composition after a short oral gluten challenge. Paraffin-stimulated whole saliva was collected from 128 CD patients and 55 healthy controls. In a separate study, paraffin-stimulated whole saliva samples were collected from 33 CD patients and 10 controls both before and 24 h after an oral mucosal and submucosal gluten challenge. No difference in saliva flow rate was observed, but total protein (P

Salivary antigliadin and antiendomysium antibodies in coeliac disease.

The definitive diagnosis of coeliac disease is based on typical changes in the small intestine biopsy specimens. To screen individuals for coeliac disease serum IgA and IgG antigliadin (AGA), IgA antireticulin (ARA) and IgA antiendomysium (EmA) antibodies are used. The aim of this study was to investigate whether these antibodies can also be detected in saliva as diagnostic markers of coeliac disease. The study population comprised 30 patients with coeliac disease treated with a gluten-free diet, 14 patients with untreated coeliac disease and 13 healthy control subjects. Sera and saliva were tested simultaneously for the presence of IgA and IgG AGA and IgA EmA. None of patients studied had a selective IgA deficiency. There was no significant difference in salivary IgA AGA levels between the three groups tested and there was no correlation between the individual serum and salivary values of IgA AGA. Salivary IgG AGA levels were very low or undetectable. Serum IgA AGA showed a low sensitivity (36.4%) to detect an untreated patient with coeliac disease. All salivary samples, regardless of the study group were negative for IgA EmA. Serum IgA EmAs were universally detected in the sera of patients with newly diagnosed coeliac disease and also in the sera of five of 30 patients with treated coeliac disease. No IgA EmA was detected in the sera of controls. None of the patients studied had a selective IgA deficiency either. Serum IgA EmA is the most sensitive, and IgA and IgG AGA are good indicators for coeliac disease, but salivary IgA or IgG AGA and salivary IgA EmA are not helpful for the diagnosis or follow-up of coeliac disease patients.

Oral mucosal changes in coeliac patients on a gluten-free diet.

Oral mucosal lesions or dental enamel defects may be the only presenting features of coeliac disease. A series of 128 patients with coeliac disease (CD) on a gluten-free diet (GFD), 8 patients with a newly diagnosed CD, and 30 healthy controls participated in a clinical and histopathological study of their oral mucosa. Oral mucosal lesions occurred in 71/128 GFD-treated CD patients. in 4/8 untreated and in 10/30 controls, and oral symptoms in 85/128, in 6/8 and in 10/30, respectively. Five CD patients had aphthous ulcers. Moderate to severe lymphocytic inflammation occurred in 36/117 and in 14/117 of the biopsy specimens of GFD-treated CD patients, in 1/8 and 2/8 of untreated CD patients, and in 3/30 and in 1/30 of controls, respectively. Intraepithelial T-cells were significantly more frequent in GFD-treated CD patients than in controls. There was no difference between untreated CD patients and controls. In the lamina propria of the GFD-treated CD patients, T-cells were more frequent than in the other groups. Mast cells were significantly more frequent in patients with GFD-treated CD. Nine GFD-treated CD patients had raised serum endomysium IgA antibody titres, although five of them reported to follow a strict GFD. A lack of strict compliance with a GFD may be related to the high prevalence of oral changes and symptoms. In addition, T-cell infiltration in the oral mucosa tends to increase with a longer duration of CD, independent of GFD-treatment. Clinically, it is important to study the oral cavity of patients suspected of having CD where the only clue to the disease may reside, since no less than 66% of the patients in this study had oral symptoms.