Production of a panel of recombinant gliadins for the characterisation of T cell reactivity in coeliac disease.
(25/1975)
BACKGROUND/AIMS: Coeliac disease is a chronic intestinal disorder most probably caused by an abnormal immune reaction to wheat gliadin. The identification of the HLA-DQ2 and HLA-DQ8 as the molecules responsible for the HLA association in coeliac disease strongly implicates a role for CD4 T cells in disease pathogenesis. Indeed, CD4 T cells specific for gliadin have been isolated from the small intestine of patients with coeliac disease. However, identification of T cell epitopes within gliadin has been hampered by the heterogeneous nature of the gliadin antigen. To aid the characterisation of gliadin T cell epitopes, multiple recombinant gliadins have been produced from a commercial Nordic wheat cultivar. METHODS: The alpha-gliadin and gamma-gliadin genes were amplified by polymerase chain reaction from cDNA and genomic DNA, cloned into a pET expression vector, and sequenced. Genes encoding mature gliadins were expressed in Escherichia coli and tested for recognition by T cells. RESULTS: In total, 16 alpha-gliadin genes with complete open reading frames were sequenced. These genes encoded 11 distinct gliadin proteins, only one of which was found in the Swiss-Prot database. Expression of these gliadin genes produced a panel of recombinant alpha-gliadin proteins of purity suitable for use as an antigen for T cell stimulation. CONCLUSION: This study provides an insight into the complexity of the gliadin antigen present in a wheat strain and has defined a panel of pure gliadin antigens that should prove invaluable for the future mapping of epitopes recognised by intestinal T cells in coeliac disease. (+info)
The effects of 1-year gluten withdrawal on bone mass, bone metabolism and nutritional status in newly-diagnosed adult coeliac disease patients.
(26/1975)
OBJECTIVES: To evaluate the impact of a 1-year gluten-free diet on bone metabolism and nutritional status in coeliac disease. METHODS: Bone mineral density, serum indices of bone remodelling, clinical and biochemical nutritional assessment were evaluated in 86 consecutive newly-diagnosed, biopsy proven, coeliac disease patients (untreated). A complete reevaluation, including intestinal biopsy, was repeated within 1 year of dietary treatment (treated). RESULTS: Untreated: according to WHO criteria, 34% of patients had a normal bone mineral density, 40% had osteopenia and 26% osteoporosis. Between males and females there were no statistical differences in bone metabolism or in most of the nutritional indices, while, between fertile and postmenopausal women, bone mineral density and several bone metabolism markers were significantly different. Compared to subjects with a normal bone mineral density, osteopenics had higher bone specific alkaline phosphatase (BAP) and Bone-Gla-protein (BGP) values. In patients with a concomitant BAP increase and 25OH vitamin D serum level reduction, bone mineral density and several bone turnover markers were statistically different compared to patients without such a serological pattern. Treated: notwithstanding intestinal biopsy which showed a mucosal recovery in only 57%, gluten-free diet led, even in postmenopausal women, to a significant improvement in bone mineral density, bone metabolism and nutrition, except for folic acid, albumin and pre-albumin serum levels which persisted as abnormal in patients with obdurate mucosal impairment. CONCLUSIONS: Coeliac disease patients are at high risk for developing a low bone mineral density and bone turnover impairment. A gluten-free diet can improve this situation even in postmenopausal women and in patients with incomplete mucosal recovery. (+info)
Lack of cellular and humoral immunological responses to oats in adults with coeliac disease.
(27/1975)
OBJECTIVE: Recent research suggests that oats do not harm intestinal villi in adults with coeliac disease. As the immunological effects of oats have not been examined in detail, it was decided to compare the immunological responses of a gluten free diet including oats with those of a conventional gluten free diet. DESIGN: A randomised controlled intervention study over 6-12 months. SUBJECTS: Forty adults with newly diagnosed coeliac disease and 52 with coeliac disease in remission were examined. INTERVENTION: The effects of a gluten free diet including oats and a conventional gluten free diet were compared. MAIN OUTCOME MEASURES: Serum levels of gliadin and reticulin antibodies as well as numbers of intraepithelial lymphocytes (IELs) in intestinal mucosa were examined before and after the intervention. RESULTS: The rate of disappearance of gliadin and reticulin antibodies did not differ between the diet groups in patients with newly diagnosed coeliac disease. Oats also had no effect on gliadin or reticulin antibody levels in the patients with remission. The number of IELs decreased similarly regardless of the diet of newly diagnosed patients, and no increase in the number of IELs was found in the patients in remission with or without oats. CONCLUSIONS: These results strengthen the view that adult patients with coeliac disease can consume moderate amounts of oats without adverse immunological effects. (+info)
Coeliac disease and unfavourable outcome of pregnancy.
(28/1975)
BACKGROUND: Up to 50% of women with untreated coeliac disease experience miscarriage or an unfavourable outcome of pregnancy. In most cases, after 6-12 months of a gluten free diet, no excess of unfavourable outcome of pregnancy is observed. The prevalence of undiagnosed coeliac disease among pregnant women is not known. AIM: To determine the prevalence of untreated coeliac disease among women attending the obstetrics-gynaecological department. METHODS: Endomysial antibodies, which are specific and sensitive for coeliac disease, were evaluated in all women attending the obstetrics-gynaecology department of a large city hospital over a 90 day period. RESULTS: Of 845 pregnant women screened, 12 were identified as having coeliac disease. Three had previously been diagnosed but were not following a gluten free diet. The remaining nine underwent a small intestinal biopsy, which confirmed the diagnosis. The outcome of pregnancy was unfavourable in seven of these 12 women. Six healthy babies were born with no problems after the women had been on a gluten free diet for one year. CONCLUSIONS: Overall, 1 in 70 women was affected by coeliac disease, either not diagnosed (nine cases) or not treated (three cases). Their history of miscarriages, anaemia, low birth weight babies, and unfavourable outcome of pregnancy suggests that testing for coeliac disease should be included in the battery of tests prescribed for pregnant women. Coeliac disease is considerably more common than most of the diseases for which pregnant women are routinely screened. Unfavourable events associated with coeliac disease may be prevented by a gluten free diet. (+info)
Enteropathy-type intestinal T-cell lymphoma: clinical features and treatment of 31 patients in a single center.
(29/1975)
PURPOSE: We report the clinical features and treatment of 31 patients with a diagnosis of enteropathy-type intestinal T-cell lymphoma treated at the Wessex Regional Medical Oncology Unit in Southampton between 1979 and 1996 (23 men, eight women). PATIENTS AND METHODS: Patients were identified from our lymphoma database. Details of history, physical examination, staging investigations, treatment, and outcome were taken from patient records. RESULTS: Twelve patients (35%) had a documented clinical history of adult-onset celiac disease, and a further three had histologic features consistent with celiac disease in resected areas of the small bowel not infiltrated with lymphoma. After diagnosis, 24 (77%) of the 31 patients were treated with chemotherapy; the remaining seven had surgical treatment alone. More than half were unable to complete their planned chemotherapy courses, often because of poor nutritional status; 12 patients required enteral or parenteral feeding. A response to initial chemotherapy was observed in 14 patients (complete response, n = 10; partial response, n = 4). Observed complications of treatment were gastrointestinal bleeding, small-bowel perforation, and the development of enterocolic fistulae. Relapses occurred 1 to 60 months from diagnosis in 79% of those who responded to initial therapy. Of the total 31 patients, 26 (84%) have died, all from progressive disease or from complications of the disease and/or its treatment. The actuarial 1- and 5-year survival rates are 38.7% and 19.7%, respectively, with 1- and 5-year failure-free survival rates of 19.4% and 3.2%, respectively. CONCLUSION: The prognosis for these patients is poor. This, in part, reflects late diagnosis and poor performance status at the time of presentation. The role of salvage treatments and high-dose chemotherapy at relapse is not clear. However, it is encouraging that there are five long-term survivors in our patient population. (+info)
The intestinal T cell response to alpha-gliadin in adult celiac disease is focused on a single deamidated glutamine targeted by tissue transglutaminase.
(30/1975)
The great majority of patients that are intolerant of wheat gluten protein due to celiac disease (CD) are human histocompatibility leukocyte antigen (HLA)-DQ2(+), and the remaining few normally express HLA-DQ8. These two class II molecules are chiefly responsible for the presentation of gluten peptides to the gluten-specific T cells that are found only in the gut of CD patients but not of controls. Interestingly, tissue transglutaminase (tTG)-mediated deamidation of gliadin plays an important role in recognition of this food antigen by intestinal T cells. Here we have used recombinant antigens to demonstrate that the intestinal T cell response to alpha-gliadin in adult CD is focused on two immunodominant, DQ2-restricted peptides that overlap by a seven-residue fragment of gliadin. We show that tTG converts a glutamine residue within this fragment into glutamic acid and that this process is critical for T cell recognition. Gluten-specific T cell lines from 16 different adult patients all responded to one or both of these deamidated peptides, indicating that these epitopes are highly relevant to disease pathology. Binding studies showed that the deamidated peptides displayed an increased affinity for DQ2, a molecule known to preferentially bind peptides containing negatively charged residues. Interestingly, the modified glutamine is accommodated in different pockets of DQ2 for the different epitopes. These results suggest modifications of anchor residues that lead to an improved affinity for major histocompatibility complex (MHC), and altered conformation of the peptide-MHC complex may be a critical factor leading to T cell responses to gliadin and the oral intolerance of gluten found in CD. (+info)
Search for coeliac disease susceptibility loci on 7q11.23 candidate region: absence of association with the ELN17 microsatellite marker.
(31/1975)
The involvement of HLA genes in the susceptibility to coeliac disease (CD) has been well documented and represents the only consistently observed genetic feature of this multifactorial disease. In the present study, the search for new susceptibility genes has been devoted to a candidate region suggested by the association of CD with Williams syndrome (WS). This genetic disorder is due to a deletion in the 7q11.23 region that includes the elastin (ELN) gene. An increased prevalence of CD in WS patients has been previously reported and a case of CD-WS is also described in the present study. We used the ELN17 microsatellite marker mapped within the ELN gene to look for a possible contribution of this region to the susceptibility to CD. The analysis of 74 Italian CD families provided no evidence of association with the ELN17 marker. (+info)
The pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence of duodenal pathology.
(32/1975)
AIM: To determine whether the pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence or absence of duodenal pathology. METHODS: 50 cases (M:F, 26:24; median age 57 years) diagnosed as lymphocytic gastritis between 1986 and 1998 with concurrent duodenal (D2) biopsies were identified from a computer search of the pathology records and validated by counting gastric intraepithelial lymphocytes. Gastric and duodenal intraepithelial lymphocyte counts were performed on haematoxylin and eosin (H&E) and anti-CD3 stained sections. D2 biopsies were assessed for villous atrophy and chronic inflammatory cell infiltration by subjective grading, and gastritis was classified and graded according to the updated Sydney system. A case was designated corpus predominant when the corpus chronic inflammation grade exceeded that of the antrum. If it was less, then the case was antrum predominant, and if they were equal it was diffuse (pan-) gastritis. The ratio between the corpus and antral intraepithelial lymphocyte count in individual patients was calculated. RESULTS: Of 50 cases of lymphocytic gastritis, 21 were classified as corpus predominant. With one exception (a case of mild villous atrophy), all were accompanied by normal duodenal morphology. Cases with a corpus predominant gastritis had median duodenal intraepithelial lymphocyte counts of 19 (H&E) and 14.1 (CD3), whereas 29 subjects with an antrum predominant or diffuse gastritis had median counts of 39.9 (H&E) and 37.9 (CD3). Fifteen of these 29 cases (52%) showed villous atrophy; all were graded as moderate or severe. Patients with any degree of villous atrophy had a mean corpus/antrum intraepithelial lymphocyte ratio (H&E) of 0.59 (representing antral predominance), while those with normal duodenal morphology had a ratio of 2.39 (p < 0.0001). CONCLUSIONS: The pattern of involvement of gastric mucosa in lymphocytic gastritis is closely related to the associated duodenal pathology. Those with the corpus predominant form are unlikely to have duodenal pathology, while those with an antral predominant or diffuse form should have distal duodenal biopsies taken to exclude villous atrophy. (+info)