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R Troncone

Publications and source records attributed to R Troncone.

At least 37 records · Page 2Linked to original sources
PubMed2001

Analysis and clinical effects of gluten in coeliac disease.

The prolamin working group coordinates research on laboratory gluten analysis in food and on clinical evaluation of patient sensitivity to prolamins. As an observer organization to the Codex Alimentarius Commission, the group summarizes current data on analysis and effects of gluten in coeliac disease. All types of gliadin, the ethanol-soluble fraction of gluten, contain the coeliac-active factor. However, coeliac toxicity and immunogenicity (humoral and cellular) of various prolamins are not identical in coeliac patients. There are no conclusive data on the threshold of gluten sensitivity of coeliac patients. Information as to the long-term risk to coeliac patients exposed to small doses of gliadin is lacking. Therefore, every effort should be made to keep the diet of coeliac patients as gluten-free as possible. The prolamin group is currently evaluating a new enzyme-linked immunosorbent assay (ELISA) protocol for gluten analysis that could serve as a basis for further Codex regulations. The group recommends adherence to a single Codex limit for gluten-free foods. The current limit of 200 ppm gluten is questionable and requires reconsideration based on new information that will be available soon.

Celiac Disease↗
PubMed2001

Treatment of giardiasis reverses "active" coeliac disease to "latent" coeliac disease.

In patients with coeliac disease, a regression of intestinal damage without a gluten-free diet is a very rare event. We describe a young child with diarrhoea, intestinal mucosa atrophy and positive serum anti-endomysial and anti-tissue transglutaminase (anti-tTG) antibodies during intestinal giardiasis infection. He showed normal intestinal mucosa architecture and negative anti-endomysial and anti-tTG antibodies after his giardiasis was cured, although he continued to assume a normal diet. Re-evaluations on a 6-monthly basis showed that he was symptom free, and all haemato-chemical parameters were within normal limits. Three years after the initial diagnosis, a third intestinal biopsy showed: normal mucosa architecture; an increase in the intra-epithelial CD3+ and gamma/delta+ lymphocyte counts; and immunoglobulin-A anti-endomysial antibody detection in the supernatant of the intestinal mucosa culture incubated with gliadin. An active coeliac disease status, with intestinal mucosa atrophy, may regress to a latent coeliac disease status with normal intestinal mucosa histology after removal of the environmental factors that have presumably precipitated mucosa damage. Serum anti-endomysial and anti-tTG antibody behaviour is not a permanent, life-long feature and this must recommend the repetition of anti-endomysial or anti-tTG antibody assays in the same patient whenever coeliac disease diagnosis is again suspected, irrespective of previous negativity.

Antiprotozoal Agents↗
PubMed2001

Keratinocyte growth factor and coeliac disease.

BACKGROUND: Coeliac disease is characterised by increased epithelial renewal associated with a mucosal T cell response to gliadin. Keratinocyte growth factor (KGF) is produced by cytokine activated gut stromal cells and may be a link between mucosal T cell activation in untreated coeliac disease and epithelial hyperplasia. AIMS: To characterise expression of KGF in coeliac disease. METHODS: KGF transcripts in coeliac disease were measured by quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) and localised using in situ hybridisation. KGF production by gluten reactive CD4+ T cell clones was examined. In addition, KGF transcripts were measured following ex vivo challenge of coeliac biopsies with a peptic-tryptic digest of gliadin. RESULTS: KGF transcripts were elevated in coeliac biopsies compared with normal controls but were not different from non-coeliac disease controls. By in situ hybridisation, KGF mRNA containing cells were present in the upper half of the lamina propria, most abundantly just under the epithelium. There was no signal from cells within the epithelium. Gluten reactive T cell clones did not make KGF. In vitro challenge of coeliac biopsies generated a strong interferon gamma response but a specific KGF response could not be detected because of an extremely high number of KGF transcripts in all cultured biopsies. CONCLUSIONS: KGF is overexpressed in coeliac biopsies and in tissues with non-coeliac enteropathy. No evidence was found for KGF production by intraepithelial lymphocytes or lamina propria T cells.

Adolescent↗
PubMed2000

Tissue transglutaminase is the target in both rodent and primate tissues for celiac disease-specific autoantibodies.

BACKGROUND: Endomysial antibodies have recently been shown to react with tissue transglutaminase. This study was undertaken to investigate whether the tissue distribution of transglutaminase is also compatible with reticulin, jejunal, and fibroblast autoantibody binding patterns. METHODS: Sera from patients with and without celiac disease, monoclonal tissue transglutaminase antibodies, and sera from mice parenterally immunized against commercially available tissue transglutaminase, transglutaminase complexed with gliadin, or gliadin were used in indirect immunofluorescence and double-staining studies using both rodent and primate tissues as substrates. Also, antibody competition, affinity chromatography, and potassium thiocyanate extraction studies were undertaken. RESULTS: Tissue transglutaminase antibody binding patterns were identical with the extracellular binding patterns seen with celiac patient sera. Human umbilical cord-derived fibroblasts exhibited both cytoplasmic and extracellular matrix staining. Double staining with patients' sera and tissue transglutaminase antibodies showed complete overlapping. Tissue transglutaminase effectively absorbed reticulin-endomysial antibodies from celiac sera, and patients' sera blocked the staining of the monoclonal tissue transglutaminase antibodies. Potassium thiocyanate extraction abolished the staining patterns, but they were elicited again after readdition of tissue transglutaminase. CONCLUSIONS: Reticulin, endomysial, and jejunal antibodies detect transglutaminase in both rodent and primate tissues, indicating that these tissue autoantibodies are identical.

Animals↗
PubMed2000

Coeliac disease and unfavourable outcome of pregnancy.

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.

Abortion, Spontaneous↗
PubMed1999

Unusual association of thyroiditis, Addison's disease, ovarian failure and celiac disease in a young woman.

The coexistence of autoimmune endocrine diseases, particularly autoimmune thyroid disease and celiac disease (CD), has recently been reported. We here present a 23-year-old woman with a diagnosis of hypothyroidism due to Hashimoto's thyroiditis, autoimmune Addison's disease, and kariotypically normal spontaneous premature ovarian failure. Considering the close association between autoimmune diseases and CD, we decided to search for IgA anti-endomysium antibodies (EmA) in the serum. The positivity of EmA and the presence of total villous atrophy at jejunal biopsy allowed the diagnosis of CD. On a gluten-free diet the patient showed a marked clinical improvement accompanied, over a 3-month period, by a progressive decrease in the need for thyroid and adrenal replacement therapies. After 6 months, serum EmA became negative and after 12 months a new jejunal biopsy showed complete mucosal recovery. After 18 months on gluten-free diet, the anti-thyroid antibodies titre decreased significantly, and we could discontinue thyroid substitutive therapy. This case emphasizes the association between autoimmune polyglandular disease and CD; the precocious identification of these cases is clinically relevant not only for the high risk of complications (e.g. lymphoma) inherent to untreated CD, but also because CD is one of the causes for the failure of substitute hormonal therapy in patients with autoimmune thyroid disease.

Addison Disease↗
PubMed1999

HLA-DR53 molecules are associated with susceptibility to celiac disease and selectively bind gliadin-derived peptides.

Celiac disease (CD) patients usually express a DQ2 heterodimer, whose chains DQalpha1*0501/DQbeta1*0201, are encoded by the genes HLA-DQA1*0501 and DQB1*0201, respectively. Among the DQ2 carriers, the risk of developing disease was shown to correlate with the number of DQbeta1*0201 chains encoded. Studying two separate cohorts of Italian and Tunisian patients, we now show a significant association of celiac disease with expression of either the DQ2 or DR53 heterodimers. The risk is maximal for individuals that carry both DQ2 and DR53 heterodimers. When twenty synthetic peptides overlapping most of A-gliadin sequence were tested for the binding to various purified DR molecules, it was found that DR53 molecules bind selectively and with high affinity (IC50<1 microM) to A-gliadin-derived peptides. These data suggest that both HLA DQ2 and DR53 molecules are associated with increased genetic risk for CD, and provide a possible biochemical basis for this complex association.

Binding, Competitive↗
PubMed1999

IgA antibodies to tissue transglutaminase: An effective diagnostic test for celiac disease.

OBJECTIVE: Tissue transglutaminase (tTG) is the main autoantigen recognized by endomysial antibodies. The aim of this study was to assess sensitivity, specificity, and predictive value of IgA and IgG antibodies to tTG in the diagnosis of celiac disease compared with endomysial antibodies. STUDY DESIGN: We established enzyme-linked immunosorbent assay procedures to measure IgA and IgG antibodies to tTG in sera from 48 untreated and 33 treated patients with celiac disease and from 63 patients with gastrointestinal disease who were in a control group. Sera from 10 patients with celiac disease were examined at various times after gluten was reintroduced into the patients' diet. RESULTS: Both IgA and IgG to tTG were significantly (P <.001) higher in serum of untreated patients with celiac disease versus those in the control group; IgA but not IgG was significantly (P <.001) higher in untreated versus treated patients with celiac disease. IgA and IgG antitissue tTG had a diagnostic sensitivity, specificity, and positive predictive value of 92% and 21%, 98% and 97%, and 98% and 83%, respectively. The concordance rate of IgA anti-tTG with IgA antiendomysial antibodies was 95%. In 5 of the 10 patients undergoing gluten challenge, IgA antiendomysium antibodies were detected earlier than IgA anti-tTG antibodies. CONCLUSIONS: tTG-based enzyme-linked immunosorbent assay is an effective diagnostic test, although immunofluorescent-based assays are more sensitive, particularly during gluten challenge.

Adolescent↗
PubMed1999

Intravenous or intranasal administration of gliadin is able to down-regulate the specific immune response in mice.

The mucosal lesion in coeliac disease (CD) represents an immunologically mediated injury triggered by gliadin and is restricted by a particular assortment of major histocompatibility complex (MHC) class II genes. Therefore, immunomodulatory strategies to tolerize gliadin-specific, class II-restricted T-cell responses could represent an alternative to current treatments of CD, which are based on a gluten-free diet. In this study, BALB/c mice derived from a gluten-free diet colony were tolerized by either intranasal (i.n.) or intravenous (i.v.) administration of single or multiple doses of gliadin. While a single dose failed to induce tolerance, a significant decrease in gliadin-specific T-cell proliferation was detected (P < 0.001) after multiple i.n. or i.v. administrations. No significant difference in antibody titre was detected for antigen-specific immunoglobulin G (IgG) or the IgG1 subclass, but a lower IgG2a-specific titre was observed. Both interferon-gamma (IFN-gamma) and interleukin (IL)-2 expression, measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR), were reduced on antigen administration, both i.v. and i.n. Neither regimen showed a regulatory effect on IL-4 production. As T helper 1 (Th1) cytokines seem to be important in the pathogenesis of CD, our data therefore highlight the potential of i.n. and i.v. routes for the design of useful immunomodulatory strategies for CD.

Administration, Intranasal↗
PubMed1999

Increased concentrations of eosinophilic cationic protein in whole-gut lavage fluid from children with inflammatory bowel disease.

BACKGROUND: Eosinophils may be involved in the pathogenesis of inflammation in inflammatory bowel disease. The purpose of this study was to verify whether concentrations of eosinophilic cationic protein in gut lavage fluid from children with inflammatory bowel disease correlate with clinical and laboratory indexes of disease activity. METHODS: Twenty-three children with Crohn's disease, 14 with ulcerative colitis, and 22 age-matched control subjects entered the study. Radioimmunoassay and sandwich enzyme-linked immunosorbent assay techniques were used to measure eosinophilic cationic protein, total immunoglobulin G and interleukin-1beta, respectively. RESULTS: Gut lavage eosinophilic cationic protein levels were significantly (p < 0.005) higher in patients with Crohn's disease and ulcerative colitis than in control subjects. Intestinal eosinophilic cationic protein levels decreased in three of four children with Crohn's disease who were fed an elemental diet. There was a significant (p < 0.001) correlation between eosinophilic cationic protein concentrations and immunoglobulin G and interleukin-1beta levels in gut lavage fluid. CONCLUSIONS: Elevated intestinal eosinophilic cationic protein levels in inflammatory bowel disease suggest that eosinophils are involved in the gastrointestinal inflammation in this disease. Intestinal eosinophilic cationic protein concentration is another marker with which to discriminate between active and inactive inflammatory bowel disease.

Adolescent↗
PubMed1999

Prevalence of coeliac disease in patients with thyroid autoimmunity.

The occurrence of autoimmune thyroid disorders among patients with coeliac disease (CD) is well documented, but the exact prevalence of CD among patients with autoimmune thyroid diseases (ATD) is as yet unclear. We screened 150 newly diagnosed patients with ATD by serum endomysial antibody detection (EmA). In 5 subjects (3.3%) EmA positivity was found; all underwent jejunal biopsy. On gluten-free diet an excellent clinical and histological response was recorded with an improvement of hypothyroidism and reduction of the thyroxine dosage. Our data suggest a significant high prevalence (3.3%) of CD in patients with ATD, in particular with Hashimoto's thyroiditis.

Adolescent↗
PubMed1999

Coeliac disease in the year 2000.

Coeliac disease is a permanent intolerance to wheat gliadins and related prolamines. Patients who have an obvious malabsorption syndrome form only a small minority of the total number of people with coeliac disease. There are, in fact, no pathognomonic clinical features, and the condition is defined and diagnosed by the presence of pathological changes in the small bowel mucosa related to the presence of toxic prolamines. Susceptibility to coeliac disease is determined to a significant extent by genetic factors. A large part of the genetic susceptibility maps to the HLA region on chromosome 6, as approximately 95% of coeliac disease patients carry an almost identical HLA DQ2/heterodimer; a role of non-HLA genes has also been postulated. From a pathogenetic point of view, most evidence supports the notion of a DQ-restricted gluten-specific Th1 response in the lamina propria; nonetheless, it is possible that, in coeliac subjects, gluten, prior to T cell activation, could exert a direct toxic effect leading to the production of proinflammatory signals.

Celiac Disease↗