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Query: UMLS:C0007570 (celiac disease)
 13,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Molecular genetic techniques are being widely applied to the study of autoimmune diseases. Major advances have been made in diabetes, rheumatoid arthritis and coeliac disease. Work on experimental models of autoimmune uveitis suggests that similar advances will follow in this field. The application of molecular genetics to the study of immunology has lead to great advances in our understanding of the anatomy of antigen recognition. This work has lead to the identification of some of the structural determinants of antigen binding by MHC molecules and is helping to explain some MHC-disease associations. More recently, molecular studies of the T cell receptor have characterized patterns of T cell receptor expression in humans and have lead to the identification of regions of the T cell receptor critical for antigen recognition. These techniques will hopefully provide insights into the nature of autoimmunity and permit the identification of targets for disease specific immunotherapies. This review describes attempts to corelate MHC structure and function in the context of autoimmunity and discusses some of the strategies for analyzing T cell receptor usage in autoimmune disease.
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PMID:Molecular aspects of autoimmunity: a review. 138 42

The densities of T cells and of cells bearing the T cell receptors gamma/delta and alpha/delta and the surface antigens CD4 and CD8 in jejunal specimens from 21 patients with dermatitis herpetiformis were compared with those in specimens from 13 untreated adults with coeliac disease and 13 control subjects. In the lamina propria of the jejunum the median density of gamma/delta+ cells was significantly (p less than 0.001) greater in untreated patients with dermatitis herpetiformis than in control subjects (114 v 36 cells/mm2) and similar to that found in the patients with coeliac disease (115 cells/mm2). The difference in gamma/delta+ cell density between patients with dermatitis herpetiformis and control subjects was much greater in the surface epithelium of the jejunum: the median density for 14 untreated patients with dermatitis herpetiformis was 39 cells/mm, for seven patients with dermatitis herpetiformis on a gluten free diet 34 cells/mm, and for control subjects 2 cells/mm; the coeliac patients had the same density as the patients with dermatitis herpetiformis (45 cells/mm). The higher density of cells bearing the alpha/delta T cell receptor in the epithelium (median 77 cells/mm) of untreated patients with dermatitis herpetiformis was associated with a gluten containing diet; in specimens taken from patients with dermatitis herpetiformis on a gluten free diet the median density was similar to that in the control subjects (44 v 39 cells/mm). The increase in the number of lymphocytes bearing the T cell receptor gamma/delta, particularly in the epithelium of the jejunum, seems to be a constant marker for these closely related diseases, whereas the density of alpha/delta+ T cells is dependent on the diet.
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PMID:Increase of lymphocytes bearing the gamma/delta T cell receptor in the jejunum of patients with dermatitis herpetiformis. 153 1

T cells expressing the gamma delta heterodimer of the T cell receptor (TCR) were studied with respect to their occurrence and expression of gamma delta TCR variable region (V) genes in the normal gastrointestinal mucosa and in a variety of inflammatory conditions. In controls, gamma delta TCR+ cells were a minority population confined to the epithelial compartment of stomach, small bowel and colonic mucosae. Unlike in the periphery, gastro-intestinal gamma delta TCR+ intraepithelial lymphocytes (IEL) were mainly V delta 1+ (89.98 +/- 17.70%); few were V delta 2+ (6.04 +/- 13.8%) or V gamma 9+ (11.38 +/- 10.73%). All gamma delta TCR+ IEL were CD5low; nearly half were CD8+ and the remainder were CD4-CD8- 'double negatives'. There was no significant change from normal in percentages of gamma delta TCR+ IEL in H. pylori-associated gastritis, Crohn's disease and ulcerative colitis. However, in coeliac disease, gamma delta TCR+ IEL were elevated from 2.54% (+/- 1.71) in controls to 29.6% (+/- 16.1) in untreated patients (P less than 0.001) and 18.5% (+/- 7.2) in treated patients (P less than 0.001) and more were CD4-CD8-. Otherwise, gamma delta TCR+ IEL phenotypes were little changed: the majority remained V delta 1+V delta 2-V gamma 9- and all were CD5low. These data suggest that increased gamma delta TCR+ IEL are not a generalized response to intestinal inflammation or to stress proteins, although the typical V delta 1+V delta 2-V gamma 9- CD5low phenotype is retained.
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PMID:Gamma delta T cell receptor-positive cells of the human gastrointestinal mucosa: occurrence and V region gene expression in Heliobacter pylori-associated gastritis, coeliac disease and inflammatory bowel disease. 182 97

A jejunal biopsy specimen from an asymptomatic 35 year old man was studied because of a low serum titre of reticulin antibody and the finding of coeliac disease in his son. In this specimen villous structure was quite normal as was the total number of intraepithelial lymphocytes, but the number of gamma/delta T cell receptor bearing lymphocytes was 10 times higher than the mean in control subjects. Two years later a further biopsy specimen was obtained because of clinical symptoms and an increased titre of reticulin antibody. This specimen showed villous atrophy with crypt hyperplasia and increased infiltration of intraepithelial lymphocytes compatible with coeliac disease. A control biopsy specimen taken during gluten free diet showed normalisation of the villous architecture. Latent coeliac disease may be characterised by an increase in gamma/delta positive cells similar to that seen in established coeliac disease.
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PMID:Increase in gamma/delta T cell receptor bearing lymphocytes in normal small bowel mucosa in latent coeliac disease. 183 46

Immunohistochemistry with monoclonal antibodies to the T cell receptor V beta regions 5, 6, 8 and 12 was used to determine whether normal intestinal lymphocytes that are potentially exposed to many bacterially derived superantigens show any preferential expression of particular V beta regions compared with the blood. No difference between V beta expression in the mucosa and the blood was observed, suggesting that they share a common pool of alpha beta T cells and that there is no expansion of alpha beta T cells in response to bacterial "superantigens" in the gut. The T cell receptor V beta expressed by the activated T cells in the lamina propria of bowel from patients with Crohn's disease was also studied. There was no increase in V beta 8 expression in these cells, suggesting that the increase in V beta 8 observed in the blood and mesenteric nodes of patients with Crohn's disease is not of primary importance in the aetiology of the disease. Finally, V beta expression by mucosal T cells in coeliac disease was studied. There was no difference in V beta use by T cells in coeliac disease and those in the blood and normal jejunum.
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PMID:T cell receptor V beta expression by mucosal T cells. 183 73

Immunohistochemistry has been used to investigate disulfide- and non-disulfide-linked forms of the T cell receptor gamma/delta heterodimer (TcR gamma/delta) in blood and intestinal epithelium of normal human small intestine, intestine of patients with untreated coeliac disease (in whom T cells expressing TcR gamma/delta are disproportionately raised), intestine of patients with tropical malabsorption, and in the human fetus. In blood from adult volunteers, 90% of T cells expressing TcR gamma/delta use the disulfide-linked form. In contrast in the epithelium in normal small intestine, coeliac disease and tropical malabsorption, most of the T cells expressing TcR gamma/delta use the non-disulfide-linked form. This is especially prominent in untreated coeliac disease where the increase in TcR gamma/delta T cells is mainly restricted to those using the non-disulfide-linked form. In human fetal small intestinal epithelium, however, only cells using the disulfide-linked form are present. These variations in expression of different forms of TcR gamma/delta in the gut epithelium in different conditions suggests that antigen, or some as yet undefined factor may determine the frequency of each subpopulation.
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PMID:Expression of disulfide-linked and non-disulfide-linked forms of the T cell receptor gamma/delta heterodimer in human intestinal intraepithelial lymphocytes. 252 59

Studies of the morphologic and phenotypic diversity of intraepithelial T cells in human small intestine have shown them to be heterogeneous, yet distinct from most extra intestinal T cells. In this study sequential immunoenzymatic staining was used to define new intraepithelial lymphocyte subpopulations in man. In normal human jejunum approximately 6% of the intraepithelial T cells expressing CD3 (an antigen associated with the T cell receptor) do not express the T cell subset antigens CD4 or CD8. Approximately 20% of CD7+ cells (T cells and null cells) do not express CD4 or CD8 and 14% of the CD7+ cells do not express CD3 and are therefore not T cells. The CD7+, CD3+/-, CD4-, CD8- population is concentrated in the tips of the villi. In coeliac disease, the ratios of the subsets change significantly. The percentage of CD3+, 4-, 8- cells increases to 28%, the proportion of CD7+, 4-, 8- cells remains unchanged and the CD7+, CD3- (non-T cell) population is reduced to 1.4% of the CD7+ cells. In contrast, in patients with villous atrophy of uncertain aetiology, all CD4-, CD8- lymphocyte subsets are decreased compared with normal biopsies. Finally, in enteropathy associated T cell lymphoma (malignant histiocytosis of the intestine) in which the 'uninvolved mucosa' is histologically similar to untreated coeliac disease, the changes in the intraepithelial T cell sub-sets are indistinguishable from those in coeliac disease, suggesting that the lymphoma is a complication of coeliac disease.
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PMID:Changes in intraepithelial lymphocyte subpopulations in coeliac disease and enteropathy associated T cell lymphoma (malignant histiocytosis of the intestine). 278 74

Coeliac disease has a known strong linkage with the HLA complex and has also recently been linked to the T cell receptor genes but the mechanism whereby these genes confer susceptibility is not known. This study has examined two possible mechanisms: (i) direct, lectin-like binding of alpha-gliadin (the causative agent of CD) to HLA or TcR molecules and (ii) antigenic cross-reactivity between alpha-gliadin and HLA or TcR molecules. A flow cytometer was used to assess interactions between alpha-gliadin, anti-alpha-gliadin antibodies (raised in both coeliac patients and in rabbits) and EBV-transformed B cell lines from coeliac patients and HLA-matched and mismatched normal controls. The B cell lines were shown to express HLA-DP, -DQ and -DR antigens which are also found on coeliac intestinal epithelial cells. After incubating B cell lines with alpha-gliadin over a wide range of concentrations, no binding of alpha-gliadin to any of the cell lines could be detected with either of the gliadin-specific antibodies. This suggests that HLA molecules do not bind to alpha-gliadin in a lectin-like fashion. In contrast to the B cell lines, alpha-gliadin binding to peripheral blood monocytes could be demonstrated. This binding occurred equally to patient and control monocytes and was not influenced by HLA allotype. The second possibility tested was that alpha-gliadin and the disease-associated HLA molecule bear antigenic similarities. However, neither rabbit anti-gliadin serum nor purified human alpha-gliadin antibody bound directly to the B cell lines. Using peripheral blood T cells similar results were obtained; no binding of alpha-gliadin or antibodies to alpha-gliadin was found. Thus this study shows that the HLA and TcR associations with CD are not explained by the direct binding of alpha-gliadin to these molecules nor by a sharing of antigenic determinants between alpha-gliadin and these molecules.
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PMID:Studies on the interaction between alpha-gliadin and HLA and T cell receptor molecules in coeliac disease. 326 19

Jejunal biopsy specimens from 25 patients with IgA deficiency (IgAd) were studied immunohistochemically to find markers of inflammation. Five of the 25 patients had coeliac disease (CD): they were on a gluten free diet and had normal jejunal morphology. Only two of 15 specimens from control subjects had CD25+ cells in the surface epithelium, while this was seen in 19 out of 20 specimens from IgAd patients (p < 0.0001). A significant increase of CD25+ cells was also noted in the lamina propria of IgAd patients. The median percentage of crypt cells in mitosis (Ki67+ cells) was higher in the specimens from IgAd patients (26%) than in those from controls (13%, p < 0.001). The densities of gamma delta T cell receptor positive cells in the surface epithelium and lamina propria did not differ in the specimens from IgAd patients and those of controls nor was the expression of HLA class II antigens augmented in the surface epithelium. These findings were similar for the IgAd patients whether or not the patient had DQB 0201 allele, a genetic marker which is strongly associated with CD. The inadequacy of the local immunoglobulins in patients with IgAd may lead to increased T cell activation, which is accompanied by the appearance of intraepithelial CD25+ cells and with an increase in the mitotic rate in the crypts.
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PMID:Immunohistochemical findings in jejunal specimens from patients with IgA deficiency. 748 39

Celiac disease (CD) occurs as a result of an abnormal immune response, within the mucosa of the small bowel, to dietary gliadin peptides. To further characterize the intramucosal lymphocytes in patients with untreated CD, we compared T cell receptor (TCR) variable region gene expression in small bowel biopsies from patients with CD to that of normal small bowel. We also assessed TCR genotypes, using restriction fragment length polymorphisms (RFLPs) spanning the V beta gene locus, comparing 59 CD patients to 64 normals. The abnormal immune response in CD is polyclonal, without evidence of restriction or significantly increased expression of any TCR variable region gene families, compared to normal small bowel. No significant association was found between TCR genotypes, as defined by TCR V beta RFLPs, and CD.
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PMID:T cell receptor gene expression and genotypes in celiac disease. 759


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