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PubMed2000

TCR Vbeta expression in the small bowel of patients with dermatitis herpetiformis and gluten sensitive enteropathy. Limited expression in dermatitis herpetiformis and treated asymptomatic gluten sensitive enteropathy.

Dermatitis herpetiformis (DH) is a blistering skin disease characterized by cutaneous deposits of IgA and an associated, most often asymptomatic, gluten sensitive enteropathy (GSE). Gluten sensitive enteropathy is also seen in patients that do not have skin disease or cutaneous IgA deposits, but do have significant gastrointestinal (GI) complaints. Patients with DH and with GSE without skin disease have similar small bowel morphologic changes and HLA associations and both the skin disease and the GI symptoms can be controlled by a gluten free diet. It is not known what factors allow almost all patients with DH to continue to eat gluten and not develop symptomatic gastrointestinal disease. We have examined the expression of the Vbeta T-cell receptor (TCR) in the small bowel of patients with DH (n=11) and of patients with both symptomatic (n=10) and asymptomatic (n=7) GSE without skin disease to determine if differences in the pattern of TCR Vbeta expression are associated with differences in the clinical manifestations of these diseases. TCR Vbeta expression was analyzed using RT-PCR from small bowel biopsies. Patients with DH and those with GSE without skin disease that were on a gluten free diet and asymptomatic were found to express 6.6 and 5.6 out of 20 Vbeta families respectively, with no single family preference. Examination of peripheral blood lymphocytes from these patients did not reveal any restriction of TCR Vbeta family expression. In contrast, patients with symptomatic GSE expressed 12.6 Vbeta families (P< 0.05), with no consistent preferential expression of any single Vbeta family between patients. Patients with DH, who are continuing to ingest wheat, show a more restricted pattern of TCR Vbeta utilization, similar to that of treated patients with GSE without skin disease, and significantly different from GSE without skin disease patients eating gluten. These findings suggest that the restricted nature of the TCR Vbeta expression may play a role in the different clinical manifestations of dermatitis herpetiformis and isolated gluten sensitive enteropathy.

Adolescent↗
PubMed2003

How gluten-free is gluten-free, and what does this mean to coeliac patients?

A gluten-free diet is the cornerstone treatment of coeliac disease. Until now, it is not known conclusively whether trace amounts of gluten might be allowed in the diet, as suggested by Codex Alimentarius. Gluten-free foods intended for dietary use can now be analysed reliably for residual gluten by the new R5 enzyme-linked immunosorbent assay (ELISA) system. Some major problems of gluten analysis (sensitivity, specificity, reproducibility) can be solved by the new method. Therefore, the information given by the new test system is relevant and superior to earlier methods. Further clinical studies using small dose challenges and dietary records including gluten analysis are necessary until a more meaningful discussion on standards for gluten-free foods can be started.

Celiac Disease↗
PubMed1993

Time-course of adhesion molecule expression in rectal mucosa of gluten-sensitive subjects after gluten challenge.

Adhesive interactions between endothelium and circulating cells, such as monocytes, neutrophils and lymphocytes, are crucial for localizing the inflammatory response. We investigated the inflammatory response of rectal mucosa to local gluten challenge as a dynamic model of antigen-induced tissue injury, during which the expression of adhesion molecules on leucocytes and endothelial cells could be sequentially observed. Expression of ELAM-1, ICAM-1 and VCAM-1 was monitored in 10 treated and eight untreated patients with gluten sensitivity (coeliac disease), and in five disease controls for up to 4 h (short challenge), while a further seven treated coeliacs were monitored for up to 24 h (long challenge) following rectal gluten challenge. In the former, the expression of VCAM-1 and ELAM-1 was significantly raised 4 h after gluten challenge compared with controls. VCAM-1 and ELAM-1 expression was also increased in mucosae of treated patients, but to a lesser extent. VCAM-1 expression continued to increase for up to 24 h after gluten, while ELAM-1 had begun to wane by 4 h, reaching basal levels by 24 h. In contrast, the expression of ICAM-1 did not change in any of the disease groups studied. These findings relate to significant increases in lymphocytes (CD3+ cells) after 8 h, and neutrophils (CD15+ cells) after 4 h in the lamina propria. This approach has permitted novel studies of the inflammatory response to a defined antigen in sensitized (gluten-sensitive) human patients.

Celiac Disease↗
PubMed1983

Studies of intestinal lymphoid tissue. VI--Proliferative response of small intestinal epithelial lymphocytes distinguishes gluten- from non-gluten-induced enteropathy.

Several diseases of the small intestine, including gluten-sensitivity, present with malabsorption and a "flat" mucosa. Determination of the mitotic index of epithelial lymphocytes provides a simple, objective method of assessing, and thus of predicting, whether a flat mucosa is due to gluten-sensitivity (index greater than 0.2%), or not (index less than 0.2%). The use of this index in circumstances especially likely to cause diagnostic confusion--for example, intestinal lymphoma; Crohn's jejunitis of immunodeficiency--is illustrated in this paper. Of seven cases, five (two primary lymphoma, three immunodeficiency) had been treated with a gluten-free diet without benefit; a mitotic index performed on the initial biopsy in each of these patients could have predicted from the outset that none was gluten-sensitive. Of the remaining two cases, determination of the mitotic index on the biopsy initially obtained from a man with severe hypogammaglobulinaemia would have indicated that he was also gluten-sensitive. Empirical use of a gluten-free diet was avoided in the other patient (with flat small intestinal mucosa and low mitotic index) in whom the diagnosis was ultimately shown to be due to Crohn's disease of jejunum.

Adolescent↗
PubMed1983

The lectin properties of gluten as the basis of the pathomechanism of gluten-sensitive enteropathy.

The pathogenesis of gluten-sensitive enteropathy is as yet unknown. According to one theory gluten may act as a lectin with toxic properties for the intestinal cells. We can now confirm this theory by laser nephelometric measurements and demonstrate the oligomannosyl specificity of this lectin-like protein gluten. Furthermore, we demonstrate the highly more intensive binding capacity of gluten for the glycoproteins of the immature crypt cells of the intestinal brush border compared to those from the mature villous zone. It is discussed that gluten-sensitive enteropathy is caused by a genetically determined defect-glycosylation of intestinal glycoproteins with the synthesis of more mannosylated glycoproteins.

Celiac Disease↗
PubMed1996

In siblings of celiac children, rectal gluten challenge reveals gluten sensitization not restricted to celiac HLA.

BACKGROUND & AIMS: Inflammatory changes in the rectum of patients with celiac disease after local instillation of gluten have been reported. The aim of this study was to examine rectal mucosa after local gluten challenge in children with celiac disease and their siblings. METHODS: Rectal biopsy specimens were obtained before and 6 hours after rectal challenge with a peptictryptic digest of gliadin in 33 children with treated celiac disease, 12 controls, and 19 siblings of children with celiac disease. Epithelium and lamina propria volumes were determined, and CD3+ and gamma delta + lymphocytes were counted. RESULTS: After local instillation of gliadin, a significant increment in the absolute number of intraepithelial lymphocytes was noted in patients with celiac disease but not in controls. Immunohistochemical analysis showed a significant increase in CD3+ and gamma delta + cells, with the gamma delta/CD3 ratio remaining unchanged after challenge. A discriminant analysis allowed correct classification of 100% of patients with celiac disease and controls. The same analysis was used to classify 6 of 13 siblings as having celiac disease. The positivity was not associated with the presence of the heterodimer encoded by the DQA*0501 DQB1*0201 alleles in any of the siblings. CONCLUSIONS: All patients with celiac disease were identified by rectal gluten challenge. Approximately half of the siblings reacted to rectal instillation of gluten. The genetic background of such sensitization to gluten remains to be elucidated.

Adolescent↗
PubMed1982

Intestinal permeability in coeliac disease: the response to gluten withdrawal and single-dose gluten challenge.

Intestinal permeability has been studied in 21 patients with coeliac disease in relapse and after gluten withdrawal using an oral test of intestinal permeability based on the simultaneous oral administration of two probe molecules. The increased absorption of the larger molecule (cellobiose) and the decreased absorption of the smaller (mannitol) found in untreated coeliac disease both returned to normal within five months of starting treatment, the abnormality in cellobiose absorption correcting more rapidly than that of mannitol. After exposure to a single oral dose of gluten, the intestinal permeability of six patients with treated coeliac disease became transiently abnormal with an increased absorption of cellobiose, returning to normal within one week. The possible structural and functional implications of these findings are discussed. The cellobiose/mannitol ratio appears to be of value in assessing the response to gluten withdrawal in coeliac disease, and also in monitoring patients who are already established on a gluten free diet by detecting dietary lapses and 'non-responding coeliac disease'. It may also offer an alternative to jejunal biopsy in patients subjected to gluten challenge.

Adolescent↗
PubMed2001

Two different doses of gluten show a dose-dependent response of enteropathy but not of serological markers during gluten challenge in children with coeliac disease.

UNLABELLED: In order to study dose-dependency in histopathological reactions and in changes of serological markers of mucosal relapse, gluten challenge was performed with two defined amounts of gluten in 54 children with earlier enteropathy. Gluten was provided in the form of powder and the patients were randomly allotted to either 0.2 (group A, n = 27) or 0.5 (group B, n = 27) grams per kg body weight per day. At the start and after 4 wk of challenge a small intestinal biopsy was performed. Biopsy specimens were evaluated, in accordance with defined criteria, graded and summarized in an enteropathy score. Blood was sampled at the start and after 2 and 4 wk of challenge. Serum levels of anti-gliadin antibodies (AGA) and anti-endomysium antibodies (EmA) were measured. Within 4 wk of challenge, 24 out of 27 patients in group A and all patients in group B had relapsed. After increasing the gluten dose to 0.5 g/kg/d during the subsequent 4 wk, the three non-relapsing patients also relapsed. CONCLUSION: The severity of mucosal inflammation was significantly higher for group B (p = 0.04) indicating a dose-related severity of the enteropathy. No significant difference was found for maximum AGA level, or in the proportion of patients that converted to pathological values for AGA or EmA.

Biomarkers↗
PubMed1992

Gluten, major histocompatibility complex, and the small intestine. A molecular and immunobiologic approach to the spectrum of gluten sensitivity ('celiac sprue').

This article examines associations between gluten, polymorphisms of the major histocompatibility complex, and mucosal pathology representative of the spectrum of gluten sensitivity. Sequences of wheat, rye, and barley prolamins contain recurring tetrapeptide motifs that are predicted to have beta-reverse-turn secondary structure and that, with in vitro assays, appear active. Structural polymorphisms of major histocompatibility complex subloci identify codon switches within the second exon that control the third hypervariable region in the outer domain of the beta chain. Observations of the intestinal response to gluten reveal five interrelated lesions (preinfiltrative, infiltrative, hyperplastic, destructive, and hypoplastic) that are interpretable as cell-mediated immunologic responses. These responses originate in the lamina propria, where a series of antigen-specific inflammatory processes has now been identified. There is no evidence that celiac sprue is a disease of jejunal enterocytes. Furthermore, the role of intraepithelial space lymphocytes in pathogenesis, if relevant, needs further experimental dissection. Also awaiting further definition are polymorphisms of the celiac lymphocyte antigen receptor and their relationship to gliadin oligopeptide(s) and predisposing genes. The nature and basis of nonresponsive celiac sprue require more thoughtful initiatives to elucidate the immunologic mechanism(s) of unresponsiveness and evaluate possible means of reversal. Finally, a more sensible definition of gluten sensitivity (unhampered by qualitative morphological imagery) is ultimately called for in order to accommodate the biomolecular advances addressed in this review.

Amino Acid Sequence↗
PubMed1995

Disulphide bonds in wheat gluten: cystine peptides derived from gluten proteins following peptic and thermolytic digestion.

Gluten from the wheat variety Rektor was extracted with 70% aqueous ethanol. The insoluble portion (whole glutenin) was partially hydrolysed with trypsin at pH 6.5 and separated on a Sephadex G25 column. The high molecular weight fraction 1 was further hydrolysed with pepsin at pH 2.0. To remove low molecular weight proteins, a portion of whole glutenin was extracted with dilute acetic acid. The residue (enriched glutenin), which contained mostly LMW and HMW subunits of glutenin, was hydrolysed with thermolysin at pH 6.5. The peptic and tryptic hydrolysates were separated on a Sephadex G25 column and the peptide fractions with the highest cystine content were separated further by reversed-phase high-performance liquid chromatography (RP-HPLC). Cystine peptides were detected by differential chromatography (RP-HPLC prior to and after reduction of disulphide bonds) and then isolated by preparative RP-HPLC. After reduction, cysteine peptides were alkylated and analysed for their amino acid sequence. Altogether, 19 cystine peptides were characterized and assigned to known sequences of gluten proteins; 16 peptides confirmed the positions of disulphide bonds present in LMW subunits and gamma-gliadins, as described previously. For the first time, a cystine peptide has been isolated, representing an intermolecular disulphide bond between the y-type of HMW and LMW subunits. Furthermore, a cystine peptide was assigned to gamma-gliadins; thus, all cysteine residues of gamma-gliadins are documented by at least one cystine peptide. One peptide analysed came from the alpha-amylase inhibitor CM 16. Altogether the results indicate that the intramolecular linkages of gluten proteins are not formed at random, but are strongly directed.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed2004

In vitro starch digestibility and in vivo glucose response of gluten-free foods and their gluten counterparts.

BACKGROUND: Recently there has been increasing interest in the production of gluten-free (GF) foods and studies on minor cereals and pseudocereals without celiac activity in order to fulfill the specific needs of people affected by celiac disease. GF bread, pasta, biscuits are usually manufactured using different combinations of thickenings and particular food processing procedures that could affect starch digestibility. Carbohydrates, mainly starch from cereals, play an important part in a balanced diet, and dietary guidelines suggest a diet with low glycemic index foods, that is to say rich in slowly digested carbohydrates. AIM: The present study was aimed at evaluating: 1) the importance of some GF food characteristics in relation to their effects on in vitro starch accessibility to digestion, in comparison with traditional gluten products; 2) the in vivo metabolic responses to GF foods. METHODS: Firstly, starch digestibility of several products was evaluated in vitro. Then, an in vivo study was performed on a group of healthy volunteers. Postprandial glucose and insulin responses were evaluated after administration of three GF foods and traditional bread. Triglycerides and free fatty acids (FFA) were also evaluated. Attempts were also made to explore differences in metabolic responses to GF foods in healthy subjects with respect to celiac subjects. RESULTS: The area under the curve (AUC) of digested starch of GF bread was slightly higher than that of the traditional counterpart. No significant difference was observed in AUCs of digested starch between GF pasta and the traditional pasta. The AUCs of digested starch of quinoa and the two samples of pasta were not statistically different. Significant differences were observed between GF bread and bread-like products. Statistic differences in glucose responses to GF pasta were observed between healthy and celiac subjects. In healthy subjects, the AUCs of glucose response after GF bread were higher than those after bread with gluten. No significant differences were observed between the AUCs of insulin responses to all products tested. Glycemic index (GI) for GF pasta was similar to GI for GF bread while GI for quinoa was slightly lower than that of GF pasta and bread. Two-way ANOVA revealed that quinoa induced lower FFA levels with respect to GF pasta. In addition, triglyceride concentrations were significantly reduced for quinoa with respect to GF bread and bread. CONCLUSIONS: Our results indicate that the different formulations and the food processing procedures used in the manufacturing of GF products may affect the rate of starch digestion both in vitro and in vivo. It may be worthwhile improving the formulation of these products. Furthermore, quinoa seems to represent a potential alternative to traditional foods, even if further and larger studies are required to demonstrate its hypoglycemic effects.

Adult↗
PubMed1993

Gluten exorphin C. A novel opioid peptide derived from wheat gluten.

A novel opioid peptide, Tyr-Pro-Ile-Ser-Leu, was isolated from the pepsin-trypsin-chymotrypsin digest of wheat gluten. Its IC50 values were 40 microM and 13.5 microM in the GPI and MVD assays, respectively. This peptide was named gluten exorphin C. Gluten exorphin C had a structure quite different from any of the endogenous and exogenous opioid peptides ever reported in that the N terminal Tyr was the only aromatic amino acid. The analogs containing Tyr-Pro-X-Ser-Leu were synthesized to study its structure-activity relationship. Peptides in which X was an aromatic amino acid or an aliphatic hydrophobic amino acid had opioid activity.

Amino Acid Sequence↗
PubMed1993

Transmission electron microscopy of microvilli of intestinal epithelial cells in celiac disease in remission and transient gluten enteropathy in children after a gluten-free diet.

The structure of microvilli of intestinal epithelial cells was investigated in 70 children: 34 with celiac disease in remission, 28 with transient gluten enteropathy after a gluten-free diet, and eight controls. Transmission electron microscopy was used to determine the mean thickness of the glycocalyx layer covering the microvilli, the mean length and width of microvilli, and the number of microvilli per 1 micron length of enterocyte surface. The structure of the glycocalyx was found to be intact, but in some children with treated celiac disease the layer of glycocalyx was either thin or absent on the surface of individual cell microvilli. In children with treated celiac disease, microvilli were statistically significantly shorter than those in children with transient gluten enteropathy and controls. Microvillous width in treated celiac disease was greater as compared with that in controls. There was no difference in the number of microvilli on the enterocyte surface in the three groups.

Biopsy↗
PubMed1974

An in vitro model of gluten-sensitive enteropathy. Effect of gliadin on intestinal epithelial cells of patients with gluten-sensitive enteropathy in organ culture.

Jejunal biopsy specimens from patients with gluten-sensitive enteropathy (GSE) (obtained during gluten challenge) as well as from normal individuals and patients with other gastrointestinal abnormalities were cultured in vitro for 48 h in the presence or absence of a peptic-tryptic digest (P-T digest) of gliadin. In the absence of gliadin the alkaline phosphatase activity in the biopsy specimens obtained from normal control individuals increased from an initial value of 384 +/- 83 U to a 48 h value of 561 +/- 151 U (mean +/- SD) (difference significant at P < 0.01). The initial alkaline phosphatase activity of specimens obtained from patients with GSE was strikingly lower than that of normals, 117 +/- 79 U, and increased to a 48 h value of 399 +/- 203 U (difference significant at P < 0.01). The biochemical change in cultured biopsy specimens of GSE patients correlated with increases in the length and regularity of brush borders of epithelial cells as seen with the electron microscope. In the presence of a P-T digest of gliadin, the alkaline phosphatase activity of biopsy specimens of control individuals increased from an initial value of 384 +/- 83 U to a 48 h value of 578 +/- 156 U. In contrast, the alkaline phosphatase activity of biopsy specimens of patients with GSE in exacerbation showed a markedly diminished increase in activity during 48 h of culture; in this case the initial activity was 117 +/- 79 U and the final activity was 203 +/- 93 U. This inhibitory effect on increase of alkaline phosphatase activity during organ culture was specific in that a P-T digest of casein (a protein not toxic in vivo to patients with GSE) had no effect on alkaline phosphatase increases in culture. Finally, these results obtained with biopsy specimens taken from patients with GSE in exacerbation were compared with results obtained from patients with GSE in remission. Alkaline phosphatase activity of specimens obtained from the latter group of patients also increased during culture but in this instance P-T digest of gliadin in the culture medium had no significant inhibitory effect. In conclusion, the inhibitory effect of gliadin on intestinal epithelial cells in organ culture represents an in vitro model of gluten-sensitive enteropathy. Inasmuch as this effect of gliadin is not seen in cultures of specimens taken from patients in remission, it appears that gliadin is not directly toxic to GSE jejunal mucosa per se, but rather toxicity requires the participation of an endogenous effector mechanism which must first be stimulated in vivo.

Adolescent↗
PubMed1980

Immunoglobulin-producing cells in jejunal mucosa of children with coeliac disease on a gluten-free diet and after gluten challenge.

The jejunal Ig-producing cell populations in a group of 12 children with established coeliac disease (CD) in remission on a gluten-free diet were compared with those of a group of 10 patients in clinical relapse after gluten challenge. Quantification of the various immunocyte classes was performed by paired immunofluorescence staining in an individually defined mucosal tissue unit constituting a 6-micron-thick and 500-micron-wide block of tissue, including the mucosa at full height from the muscularis mucosae. In the treated group the percentage IgA/IgM/IgG cell ratios were, on the average, 82.6:12.9:4.5. There were no differences in these ratios or in the absolute immunocyte numbers when compared with a group of six control patients without CD. After gluten challenge the corresponding ratios were 77.2:17.2:5.6. The median cell number per mucosal tissue unit in the IgA, IgM, and IgG class was raised 2.1, 3.8 and 2.9 times, respectively. These increases were statistically significant. Moreover, there was a significant negative correlation between the time to clinical relapse and the number of IgG cells per tissue unit after challenge. This finding indicates that locally produced antibodies of the IgG class are especially involved in the pathogenesis of CD.

Antibody-Producing Cells↗
PubMed1980

Skin test for gluten-sensitive enteropathy using subfractions of gluten.

Fractions and subfractions of gluten were used for intradermal testing in 14 patients with GSE and in 22 control subjects. Twelve out of 14 GSE patients gave positive skin reactions to one or more of the subfractions of gluten. Ten gave a positive reaction between three to eight hours after skin testing; two gave positive tests 20 minutes after injection. Only two out of the 14 had negative skin tests at all times tested. All 22 control subjects were negative to all the subfractions at all times tested. The control subjects consisted of 15 patients with GI disorders other than GSE, three patients with skin disorders other than dermatitis herpetiformis and four healthy controls. Of the three subfractions tested, subfraction B1 appeared most potent in evoking positive skin reactions as judged by the number of GSE patients who responded (11 of 14). Thus, skin testing individuals with this particular portion of gluten subfraction BA may prove to be a useful diagnostic test for GSE.

Adolescent↗
PubMed1983

Gluten-sensitive enteropathy: value of oral triglyceride loading test in the follow-up of patients on gluten challenge.

Oral triglyceride (TG) loading tests were performed in 31 patients with gluten-sensitive enteropathy (GSE) upon gluten challenge, and the results were compared with the mucosal histology. Of 19 prechallenge tests, 16 were in the normal range previously established in this laboratory (2-h postcibal plasma TG rise greater than or equal to 55 mg/dl) although values were lower (76 +/- 38 mg/dl, mean +/- SD) than those of healthy age-matched controls (116 +/- 34 mg/dl). Postchallenge tests performed in 29 patients (both symptomatic and asymptomatic) were all pathologic (postcibal TG rise 9 +/- 18 mg/dl). Three tests performed in two patients in whom GSE was ultimately not confirmed remained normal (postcibal TG rise 82 +/- 21 mg/dl) during a 24-mo follow-up. A significant correlation was demonstrated between the TG loading test and the mucosal pathology. The test is useful in the follow-up of patients of gluten challenge and in directing the postchallenge biopsy.

Administration, Oral↗
PubMed1977

Wheat grains: a substrate for the determination of gluten antibodies in serum of gluten-sensitive patients.

A simple method of detecting gluten antibodies in serum is described. Cryostat sections of wheat grains proved to be an excellent substrate in the immunofluorescence technique. Rabbit antisera to gliadin and alpha-gliadin, and high percentage of sera from patients with gluten-induced enteropathy had antibodies that reacted with an internal structure of wheat grains. These antibodies could be absorbed with gliadin and with alpha-gliadin.

Adult↗