Gluten and other food protein antigens make their way through human bodies in a remarkable fashion. There are many potential paths from mouth to target organ for food antigens to follow. Every tissue of the body can manifest a food allergic response. Some activity is noticed in minutes; the onset of other activity is delayed hours to days. Manifestations include both systemic symptoms such as flushing, fever, aching, fatigue, and also localized target organ activity, usually some form of inflammation, manifest as pain, swelling, erythema, and local heat.

Food antigens may enter and then complex with antibody in the GIT wall causing local inflammation and increased permeability. Immune complexes may form in the gut submucosa and pass through lymphatics or capillaries in the general circulation. Food proteins may enter the circulation and be identified by circulating antibodies, forming circulating immune complexes (CICs). CICs in the portal circulation pass to the liver where they may be cleared by macrophages. However, if the immune complexes are passed beyond the liver, they will then circulate through the lungs that act as secondary filters and may suffer CIC-triggered inflammatory events. Complexes can activate the complement cascade anywhere in the circulation, triggering explosive events such as anaphylaxis with both local and general symptoms. During the acute phase of a reaction, patients may be acutely distressed and present with anxiety or panic.

An asthmatic with immediate hypersensitivity typically experiences an acute wheezing attack within minutes of exposure to an airborne of allergen. This initial attack is followed by remission for a few hours, but then dyspnea returns. The second or late phase is associated with bronchiolar inflammation, airway obstruction, not responsive to bronchodilators and a more prolonged and serious threat to respiration ensues.

The variable delay of absorption of food antigens and the biphasic asthma response to discrete antigen challenge makes for a confusing variability in the timing of symptom-sequences following food ingestion. Further confusion arises when antigen challenge comes from food eaten everyday and acute responses overly chronic inflammatory activity in a complex and variable system of symptom production. If antigen in a free form, complexed with serum proteins, or complexed with antibody continues to circulate in the blood, a lottery of whole-body contingencies lies beyond the lungs. A typical symptom sequence might combine nose and throat symptoms with generalized connective tissue mediator activity, felt as muscle tension, aching, and stiffness.

In ulcerative colitis and Crohn's disease, for example, antigens enter through the gut mucosa, travel to the eye and bind to the basement membrane of the uvea and episcleral vessels triggering anterior uveitis and episcleritis. "In ulcerative colitis, membrane bound antigens may be attacked by antibody and cytotoxic lymphocytes, leading to complement pathway activation and associated acute inflammatory cell infiltrate." In SLE, retinal vasculitis produces cotton wool spots, retinal hemorrhages, retinal and optic nerve edema. The cotton wool spots are thought to represent sites of infarction in the nerve fiber layer when deposition of CICs has taken place in the capillaries.

Abstracts

Gluten specific, HLA-DQ restricted T cells from coeliac mucosa produce cytokines with Th1 or Th0 profile dominated by interferon gamma.

Author Nilsen EM; Lundin KE; KrajÅci P; Scott H; Sollid LM; Brandtzaeg P

Address Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Institute of Pathology, Oslo, Norway.

Source Gut, 1995 Dec, 37:6, 766-76

 

Abstract Coeliac disease is precipitated in susceptible subjects by ingestion of wheat gluten or gluten related prolamins from some other cereals. The disease is strongly associated with certain HLA-DQ heterodimers, for example, DQ2 (DQ alpha 1*0501, beta 1*0201) in most patients and apparently DQ8 (DQ alpha 1*0301, beta 1*0302) in a small subset. Gluten specific T cell clones (TCC) from coeliac intestinal lesions were recently established and found to be mainly restricted by HLA-DQ2 or HLA-DQ8. Antigen induced production of cytokines was studied in 15 TCC from three patients, 10 being DQ2 and five DQ8 restricted. Cell culture supernatants were prepared by stimulation with gluten peptides in the presence of DQ2+ or DQ8+ Epstein-Barr virus transformed B cells as antigen presenting cells (APC). Supernatants were analysed for cytokines by bioassays, ELISA, and CELISA. Cellular cytokine mRNA was analysed semi-quantitatively by slot blotting and polymerase chain reaction (PCR). All TCC were found to secrete interferon (IFN) gamma, often at high concentrations ( 2000 U/ml); some secreted in addition interleukin (IL) 4, IL 5, IL 6, IL 10, tumour necrosis factor (TNF), and transforming growth factor (TGF) beta. The last TCC thus displayed a Th0-like cytokine pattern. However, other TCC produced IFN gamma and TNF but no IL 4, or IL 5, compatible with a Th1-like pattern. In conclusion, most DQ8 restricted TCC seemed to fit with a Th0 profile whereas the DQ2 restricted TCC secreted cytokines more compatible with a Th1 pattern. The TCC supernatants induced upregulation of HLA-DR and secretory component (poly-Ig receptor) in the colonic adenocarcinoma cell line HT-29.E10, most probably reflecting mainly the high IFN gamma concentrations. This cytokine, particularly in combination with TNF alpha, might be involved in several pathological features of the coeliac lesion. The characterised cytokine profiles thus support the notion that mucosal T cells activated in situ by gluten in a DQ restricted fashion play a central part in the pathogenesis of coeliac disease.

The gluten-host interaction

Author Tighe MR; Ciclitira PJ

Address Division of Pharmacology, United Medical and Dental Schools of Guy's Hospital, London, UK.

Source Baillieres Clin Gastroenterol, 1995 Jun, 9:2, 211-30

 

Abstract Work continues to progress in the unravelling of the molecular interactions involved in the pathogenesis of coeliac disease. The immunogenetics of the disease implicate certain HLA DQ alleles as necessary for subsequent disease development. These HLA molecules have been shown to be necessary in the binding and presentation of gliadin peptides to antigen-specific T cells. Current work is examining the precise HLA-antigen interaction that may lead to the development of antigen-blocking agents. The isolation of antigen-specific T cells has led to the confirmation of a toxic T-cell epitope of the gliadin protein (residues 31-49) and it would appear likely that additional toxic epitopes may be similarly characterized in the near future. No common TCR motifs have so far been detected, although these may become apparent as this work progresses. The gliadin peptide sequence, residues 31-49, has now been demonstrated to be toxic in vivo. Additional toxic T-cell epitopes may also be present within gliadins, but this identification of a toxic gliadin sequence for the first time raises the possibility of future manipulation of the wheat genome (and other toxic cereals) that could lead to the development of new graminae cereals with the properties of wheat, but which do not induce toxicity in patients with coeliac disease.

Gliadin-specific T cell responses in peripheral blood of healthy individuals involve T cells

Author Jensen K; Sollid LM; Scott H; Paulsen G; Kett K; Thorsby E; Lundin KE

Address Institute of Transplantation Immunology, University of Oslo, Norway.

Source Scand J Immunol, 1995 Jul, 42:1, 166-70

 

Abstract Coeliac disease (CD) is probably caused by an abnormal immune response towards wheat gliadin in the small intestine. We found that gliadin-specific T cells from the small intestinal mucosa of HLA-DQ2 positive CD patients were almost exclusively restricted by the disease-associated DQ2 molecule. In the peripheral blood of CD patients, a large proportion of gliadin-specific T cells were found to be restricted by DQ molecules, including DQ2, but many were instead restricted by DR or DP molecules of the patient. We have now investigated gliadin-specific T cell responses in peripheral blood from healthy individuals. Four of 20 persons tested had strong in vitro responses and were used as donors for gliadin-specific T cell clones. We found gliadin-specific T cells restricted by the CD-associated DQ2 molecule in peripheral blood for two of these four individuals. It is the presence of such T cells also in the small intestinal mucosa which seems typical of CD.

Role of T cell receptor delta gene in susceptibility to celiac disease.

Author Roschmann E; Wienker TF; Volk BA

Address Department of Internal Medicine, Division of Gastroenterology, University of Freiburg, Germany.

Source J Mol Med, 1996 Feb, 74:2, 93-8

 

Abstract There is a genetic influence on the susceptibility to celiac disease. Although in the vast majority of patients with celiac disease, the HLA-DQ(alpha1*0501, beta1*0201) heterodimer encoded by the alleles HLA-DQA1*0501 and HLA-DQB1*0201 seems to confer the primary disease susceptibility, it cannot be excluded that other genes contribute to disease susceptibility, as indicated by the difference in concordance rates between monozygotic twins and HLA identical siblings (70% vs. 30%). Obviously other genes involved in the genetic control of T cell mediated immune response could potentially influence susceptibility to celiac disease. The density of T cells using the gammadelta T cell receptor (TCR) is considerably increased in the jejunal epithelium of patients with celiac disease, an abnormality considered to be specific for celiac disease. This suggests an involvement of gammadelta T cells in the pathogenesis of the disease. To ascertain whether the TCR delta (TCRD) gene contributes to celiac disease susceptibility we carried out an association study and genetic linkage analysis using a highly polymorphic microsatellite marker at the TCRD locus on chromosome 14q11.2. The association study demonstrated no significant difference in allele frequencies of the TCRD gene marker between celiac disease patients and controls; accordingly, the relative risk estimates did not reach the level of statistical significance. In the linkage analysis, performed in 23 families, the logarithm of the odds (LOD) scores calculated for celiac disease versus the TCRD gene marker excluded linkage, suggesting that there is no determinant contributing to celiac disease status at or 5 cM distant to the analyzed TCRD gene marker. In conclusion, the results of the present study provide no evidence that the analyzed TCRD gene contributes substantially to celiac disease susceptibility.

pithelial cell proliferation in childhood enteropathies.

Author Savidge TC; Shmakov AN; Walker-Smith JA; Phillips AD

Address Academic Department of Paediatric Gastroenterology, Queen Elizabeth Hospital for Children, London.

Source Gut, 1996 Aug, 39:2, 185-93

 

Abstract BACKGROUND/AIM: The aim of this study was to investigate epithelial cell turnover in childhood enteropathy to establish whether common disease related mechanisms operate. Levels of epithelial cell proliferation were measured in children with food intolerance (cows' milk protein intolerance and coeliac disease), and after infection with Giardia lamblia, Cryptosporidium, and enteropathogenic Escherichia coli. METHODS: Comparative measures of epithelial cell proliferation were performed by recording mitotic activity and MIB-1 immunoreactivity in proximal small intestinal biopsy specimens. RESULTS/CONCLUSIONS: A hyperplastic crypt response was evident in all of the disease states examined and was particularly pronounced in coeliac disease and in infection with enteropathogenic E coli, where mitotic and MIB-1 labelling indices were significantly raised above control values. In contrast with coeliac disease, increased crypt cell production rates in enteropathogenic E coli infection were also due to an expansion of the crypt proliferation compartment, without a comparable increase in crypt cell numbers. Crypt hyperplasia is therefore a common tissue response to mucosal damage in food allergy and infection, although disease specific mechanisms are evident.

Intestinal absorptive capacity, intestinal permeability and jejunal histology in HIV and their relation to diarrhoea.

Author Keating J; Bjarnason I; Somasundaram S; Macpherson A; Francis N; Price AB; Sharpstone D; Smithson J; Menzies IS; Gazzard; BG

Address Department of Medicine, Chelsea and Westminster Hospital, London.

Source Gut, 1995 Nov, 37:5, 623-9

Abstract Intestinal function is poorly defined in patients with HIV infection. Absorptive capacity and intestinal permeability were assessed using 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose in 88 HIV infected patients and the findings were correlated with the degree of immunosuppression (CD4 counts), diarrhoea, wasting, intestinal pathogen status, and histomorphometric analysis of jejunal biopsy samples. Malabsorption of 3-O-methyl-D-glucose and D-xylose was prevalent in all groups of patients with AIDS but not in asymptomatic, well patients with HIV. Malabsorption correlated significantly (r = 0.34-0.56, p < 0.005) with the degree of immune suppression and with body mass index. Increased intestinal permeability was found in all subgroups of patients. The changes in absorption-permeability were of comparable severity to those found in patients with untreated coeliac disease. Jejunal histology, however, showed only mild changes in the villus height/crypt depth ratio as compared with subtotal villus atrophy in coeliac disease. Malabsorption and increased intestinal permeability are common in AIDS patients. Malabsorption, which has nutritional implications, relates more to immune suppression than jejunal morphological changes.

Endomysial antibodies as unreliable markers for dietary transgressions in adolescents with celiac disease.

Author Troncone R; Mayer M; Spagnuolo F; Maiuri L; Greco L

Address Department of Pediatrics, University Federico II, Naples, Italy.

Source J Pediatr Gastroenterol Nutr, 1995 Jul, 21:1, 69-72

 

Abstract Adolescents with celiac disease often fail to adhere to a strict gluten-free diet. The value of endomysial antibodies in assessing the dietary compliance of such adolescents has been assessed in 23 patients divided into four groups according to their daily gluten intake. Serum endomysial antibodies were absent in all subjects on a gluten-free diet and consistently present in those ingesting 2 g/day of gluten. Only one of six and three of six teenagers with celiac disease with an intake of < 0.5 and 0.5-2 g/day, respectively, had endomysial antibodies in their serum, despite the presence in three of six and five of six of significant changes in the mucosal architecture, as shown by computerized morphometry of jejunal biopsies. In conclusion, endomysial antibodies cannot be considered a valid marker for slight dietary transgressions.

Leukotriene B4 and C4 metabolism in small intestine mucosa of children with celiac disease.

Author Shimizu T; Beijer E; Strandvik B

Address Department of Pediatrics, Juntendo University, Tokyo, Japan.

Source J Pediatr Gastroenterol Nutr, 1995 Nov, 21:4, 426-9

 

Abstract The enhanced generation of eicosanoids, including leukotrienes (LTs), may be involved in the pathophysiology of small intestine mucosal injury in patients with celiac disease. We investigated the metabolism of LTB4 and LTC4 by small intestine mucosa in patients with celiac disease by incubating biopsies of small intestine mucosa from patients and healthy subjects in media containing LTB4 and LTC4 and measuring the changes in LTB4 and cysteinyl LT concentrations in the incubation media. There was no significant degradation of LTB4 during a 60-min incubation of the small intestine mucosa from either children with celiac disease or controls. LTC4 was metabolized to LTD4 and LTE4 in a time-dependent manner by the small intestine mucosa of both patients and controls. However, the decreases in LTC4 and the increases in LTD4 and LTE4 by the intestinal mucosa from patients with celiac disease occurred more slowly than the changes observed in control experiments. Reduced catabolism of LTC4 in the small intestine mucosa due to villous atrophy may contribute to increased levels of LTC4 and may play an important role in the pathophysiology of celiac disease.

Evidence that intestinal intraepithelial lymphocytes are activated cytotoxic T cells in celiac disease but not in giardiasis.

Author Oberhuber G; Vogelsang H; Stolte M; Muthenthaler S; Kummer AJ; Radaszkiewicz T

Address Department of Clinical Pathology, University of Vienna Medical School, Austria.

Source Am J Pathol, 1996 May, 148:5, 1351-7

 

Abstract To further define intraepithelial lymphocytes (IELs) in celiac disease (CD) and giardiasis, IELs were probed for the presence of cytolytic granules containing granzyme B (GrB) and T-cell-restricted intracellular antigen (TIA)-1. The expression of TIA-1, GrB, CD3 (T-cell-receptor-associated complex), and Leu-7 (subset of natural killer cells) was studied by a sensitive three-step immunoperoxidase technique. Stained IELs were determined quantitatively, and results were expressed as number of stained IELs per 100 epithelial cells (ECs). The relative content in labeled lamina propria lymphocytes was determined and expressed as the percentage of all lamina propria cells counted. When compared with controls, CD3+ and GrB+ IELs were significantly increased (P < 0.0004) in CD paralleled by an increase in TIA-1+ IELs (P < 0.0004). In CD, the highest numbers of IELs containing GrB were found in subjects with a flat mucosa (median, 38 IELs/100 ECs, P < 0.0004), followed by cases with shortened and blunted villi (median, 8 IELs/100 ECs, P < 0.0004) and, finally, CD patients with an intact villous architecture (median, 0.5 IELs/100 ECs, P < 0.02). Except for cases with giardiasis, Leu-7+ IELs were virtually absent in all groups as were GrB+ IELs in the controls and in subjects with giardiasis. In the lamina propria of CD subjects, GrB+ lymphocytes were also significantly increased (P < 0.001), whereas controls and cases with giardiasis were essentially free of GrB+ cytotoxic T lymphocytes. The percentage of CD3+ lamina propria lymphocytes was nearly equal in all groups. In humans and mice, extensive studies revealed a GrB expression to be absolutely restricted to activated cytotoxic T lymphocytes and natural killer cells. TIA-1, on the other hand, is considered a marker of resting T lymphocytes possessing cytolytic potential. We therefore conclude that IELs are cytotoxic T cells that are in a resting state in the normal small bowel and in giardiasis. In CD, they become activated as suggested by the GrB positivity of their granules.

In vitro mucosal digestion of synthetic gliadin-derived peptides in celiac disease.

Author Cornell HJ; Rivett DE

Address Department of Applied Chemistry, Royal Melbourne Institute of Technology, Australia.

Source J Protein Chem, 1995 Jul, 14:5, 335-9

 

Abstract Two celiac-active synthetic peptides derived from the A-gliadin structure corresponding to residues 8-19 (LQPQNPSQQQPQ) and to 11-19 were digested in vitro with small intestinal mucosa from children with celiac disease in remission and from normal children. The products of digestion were separated into two fractions on the basis of M(r) <400 and M(r) 400 by gel permeation chromatography and subjected to amino acid analysis. After digestion of the dodecapeptide with celiac mucosa, 71 +/- 14% (molar) of the total digestion products remained in the M(r) 400 fraction. Glutamine, proline, serine, and asparagine were the major amino acids present. Glutamine, proline, and leucine were the major amino acids in the M(r) <400 fraction. The M(r) 400 fraction from the celiac mucosal digestion of the nonapeptide was of similar composition to the corresponding fraction from the dodecapeptide and represented 78 +/- 15% of the total products. Digestion of the two peptides with normal mucosa gave lower amounts of products in the M(r) 400 fraction, but they were of similar composition to the corresponding fractions from the celiac mucosal digestion. Peptides such as NPSQQP and QNPSQQQ may be present in the M(r) 400 fractions since glutamine and proline are present in the approximate ratio of 2:1, respectively. The results indicate a defect in the mucosal digestion of peptides which are active in an animal model of celiac disease.

Author Corazza GR; Andreani ML; Biagi F; Bonvicini F; Bernardi M; Gasbarrini G

Address Dipartimento di Medicina Interna dell'UniversitÄa dell'Aquila, Italy.

Source Am J Gastroenterol, 1996 Oct, 91:10, 2203-7

 

Abstract We report the clinical, pathological, and serological findings of three adult patients with latent celiac disease. The initial intestinal biopsies, which were normal, were carried out in the first case during an upper gastrointestinal endoscopy performed for a duodenal ulcer, in the second case for first-degree familiarity with a celiac patient, and in the third case because of the presence of malabsorption symptoms. In all three cases, intraepithelial lymphocytes were within the normal range in the first biopsy and cannot, therefore, be considered as a marker of latent celiac disease. In only two of the three patients was it possible to carry out the search for the serum antibodies connected with celiac disease at the time of the first biopsy. In both these cases, the antijejunal antibodies were present before the development of the intestinal lesions.

IgA and IgG binding components of wheat, rye, barley and oats recognized by immunoblotting analysis with sera from adult atopic dermatitis patients.

Author Varjonen E; Kalimo K; Savolainen J; Vainio E

Address Department of Dermatology, Helsinki University Central Hospital, Finland.

Source Int Arch Allergy Immunol, 1996 Sep, 111:1, 55-63

Abstract IgA and IgG antibody response of adult atopic dermatitis patients against neutral/ acidic fractions of wheat, rye, barley and oats was analyzed utilizing an immunoblotting method. Moreover, the antibody response against ethanol-soluble fraction of wheat was examined with serum pools of healthy donors, atopic dermatitis patients and patients with dermatitis herpetiformis or adult celiac disease. All patient sera revealed polymorphic IgA and IgG binding to cereal peptides with molecular weights of 11-97 kD. The antibody staining was essentially identical with atopic dermatitis patients and controls. Patients with dermatitis herpetiformis or celiac disease showed more intensive staining with the ethanol extract of wheat and showed more IgA-stained bands in immunoblotting. It seems that the presence of IgA and IgG antibodies to different cereal antigens is a result of natural exposure and in atopic dermatitis displays little diagnostic significance, in contrast to antigliadin antibody response in dermatitis herpetiformis and celiac disease.

Study of the immunohistochemistry and T cell clonality of enteropathy-associated T cell lymphoma.

Author Murray A; Cuevas EC; Jones DB; Wright DH

Address University Department of Pathology, Southampton University Hospitals, United Kingdom.

Source Am J Pathol, 1995 Feb, 146:2, 509-19

 

Abstract Specimens from 23 patients with enteropathy-associated T cell lymphoma were studied by immunohistochemistry after antigen retrieval. Specimens from 14 of these patients were investigated for the presence of clonal T cell gene rearrangements in both the tumor and the adjacent enteropathic intestine by the polymerase chain reaction. Primers for T cell receptor beta and gamma genes were used in a combination that permits the identification of approximately 90% of T cell receptor rearrangements. Clonal rearrangements of the T cell receptor were found in 13 of the 14 tumors studied. Specimens of enteropathic bowel resected with the tumor, but showing no morphological or immunohistochemical evidence of tumor involvement, showed clonal T cell receptor gene rearrangements in 11 cases. In 10 of these, the amplified DNA was of the same molecular weight in the enteropathic bowel as in the corresponding tumor. In 2 cases, sequencing the polymerase chain reaction product showed identical T cell receptor gene rearrangements in the tumor and in the adjacent intestine. Uniform staining for p53 was seen in 22 of the 23 tumors. In 9 of 19 cases studied, collections of small lymphocytes in the enteropathic bowel expressed p53. In all but one of these specimens, a clonal rearrangement of the T cell receptor genes was identified. We interpret these findings as support for the concept that enteropathy-associated T cell lymphoma arises on a background of gluten-sensitive enteropathy with evolution of neoplastic T cell clones from the reactive T cell population present in the enteropathic bowel.

Celiac disease and hypoparathyroidism: cross-reaction of endomysial antibodies with parathyroid tissue.

Author Kumar V; Valeski JE; Wortsman J

Address IMMCO Diagnostics, Inc., Buffalo, NY 14223, USA.

Source Clin Diagn Lab Immunol, 1996 Mar, 3:2, 143-6

 

Abstract Celiac disease (CD) is a gluten-sensitive enteropathy characterized by the presence of serum antibodies to endomysial reticulin and gliadin antigens. CD has been associated with various autoimmune endocrine disorders, such as diabetes. We report a rare case of idiopathic hypoparathyroidism with coexistent CD characterized by the presence of serum autoantibodies. Studies were conducted to determine the specificities of these autoantibodies and to localize the antibody binding sites by indirect immunofluorescence and immunoelectron microscopy. Sera from a patient with idiopathic hypoparathyroidism and CD and from two patients with CD alone were tested by indirect immunofluorescence for autoantibodies to parathyroid and endomysial antigens. The specificities of the antibody reactions were determined by testing the sera before and after absorption with monkey stomach tissue. In addition, immunoelectron microscopic studies were performed to determine the localization of the endomysial antigen. Indirect-immunofluorescence studies on the patient's serum were positive with the parathyroid as well as the endomysial substrate. Similar reactions were also observed with the sera of endomysial antibody-positive patients with CD. Absorption of the sera with monkey stomach powder, which is known to have the endomysial antigen, abolished the antibody activities on both the endomysial substrate and the parathyroid tissue. Immunoelectron microscopic studies showed that endomysial antibody activity was associated with antigens localized on the myocyte plasma membrane and in the intercellular spaces. Thus, reactions of the patient's serum with the parathyroid tissue were due to endomysial antibodies and were not parathyroid specific as in patients with idiopathic hypoparathyroidism who did not have coexistent CD. In conclusion, indirect-immunofluorescence tests on parathyroid tissue detect not only tissue-specific antibodies but also cross-reactive antibodies, and this should be taken into consideration when these tests are performed.

Molecular mimicry as a possible cause of autoimmune reactions in celiac disease? Antibodies to gliadin cross-react with epitopes on enterocytes.

Author TuÅckovÆa L; TlaskalovÆa-HogenovÆa H; FarrÆe MA; KarskÆa K; Rossmann P; KolÆinskÆa J; Kocna P

Address Department of Immunology and Gnotobiology, First Faculty of Medicine, Prague, Czech Republic.

Source Clin Immunol Immunopathol, 1995 Feb, 74:2, 170-6

 

Abstract Structural similarities between external antigen and self components are believed to be one of the possible causes of autoimmunity. This study describes the presence of similar structures shared by gliadin and enterocyte surface molecules recognized by antigliadin mAbs. The reactivity of mAbs to gliadin was followed by ELISA using fixed enterocytes, their brush-border membranes, or purified enterocyte antigen. The specificity of reaction was confirmed by ELISA inhibition studies and by immunohistochemical staining of rat tissue sections using biotin-avidin-peroxidase technique. Immunoprecipitation analysis of 125I-labeled intestinal epithelial cells using antigliadin mAb revealed the presence of two main cross-reactive molecules of 28 and 62 kDa. The 62-kDa and an associated 66-kDa protein were isolated by affinity chromatography. Immunoblotting analysis showed that a 28-kDa protein detected by immunoprecipitation also reacted with IgA of celiac disease patient sera.  

Identification of major rye secalins as coeliac immunoreactive proteins.

Author Rocher A; Calero M; Soriano F; MÆendez E

Address Unidad de AnÆalisis Estructural de ProteÆinas, Centro Nacional de BiotecnologÆia, Campus Universidad AutÆonoma, Cantoblanco, Madrid, Spain.

Source Biochim Biophys Acta, 1996 Jun 7, 1295:1, 13-22

 

Abstract Six distinct gamma- and omega-type secalins, together with two new low molecular mass glycoproteins, have been identified as the major coeliac immunoreactive proteins from a chloroform/methanol soluble extract from rye endosperm. These components were characterized by a combination of reverse-phase high-performance liquid chromatography, immunoblotting using a coeliac serum and microsequencing analysis. This allowed the identification of a group of secalins with different molecular masses according to their N-terminal amino-acid sequence: one omega-type secalin of 40 kDa (omega 1-40); three gamma-type secalins, one of 70 kDa (gamma-70) and two of 35 kDa (gamma-35); as well as two low molecular mass glycoproteins of 15 and 18 kDa, all exhibiting coeliac serum antigenicity. Moreover, four additional rye components, including two low molecular mass proteins, which did not react with coeliac sera, have also been identified. Analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of the three main purified coeliac immunogenic secalins, gamma-70, gamma-35 and omega 1-40, indicated molecular masses of 71457, 32240 and 39117 Da, respectively. The omega 1-40 secalin displays a significant absorption in the visible region which could be related to its peculiar low capacity to bind both coeliac sera antibodies and Coomassie brilliant blue dye.

Serum soluble interleukin-2 receptor, soluble CD8 and soluble intercellular adhesion molecule-1 levels in Crohn's disease, celiac disease, and systemic lupus erythematosus.

Author Srivastava MD; Rossi TM; Lebenthal E

Address Department of Laboratory Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.

Source Res Commun Mol Pathol Pharmacol, 1995 Jan, 87:1, 21-6

 

Abstract We investigated soluble interleukin-2 receptor (sIL-2R), soluble CD8 (sCD8) and soluble intercellular adhesion molecule-1 (sICAM-1) levels in the sera of patients with non-malignant diseases believed to have an autoimmune or immunosuppressive component, Crohn's disease, celiac disease, and systemic lupus erythematosus (SLE). Sera of healthy blood donors served as controls. All samples were analyzed by commercial ELISA kits for sIL-2R, sCD8, and sICAM-1. Our control level of sIL-2R (x +/- S.D) was 395 +/- 84 units/ml, sCD8 (x +/- S.D.) 263 +/- 90 units/ml and sICAM-1 405 +/- 118 ng/ml. The 8 Crohn's disease patients had an average sIL-2R level of 920 +/- 329 units/ml, and an average sCD8 level of 355 +/- 91 units/ml, and sICAM-1 952 +/- 329 ng/ml. The four celiac disease patients had an average sIL-2R concentration of 1740 +/- 1071 units/ml, a sCD8 level of 460 +/- 320 units/ml and sICAM-1 1221 +/- 720 ng/ml. The three systemic lupus erythematosus patients had an average sIL-2R of 1023 +/- 123 units/ml, and an average sCD8 of 395 +/- 69 units/ml, and sICAM-1 1153 +/- 219 ng/ml. Thus, sIL-2R and sICAM-1 were significantly elevated over control levels in all 3 patient groups, and sCD8 was mildly elevated. These results indicate enhanced immune activation which may be a common feature in the onset and/or progression of these idiopathic illnesses.

Elevated levels of serum antibodies to the lectin wheat germ agglutinin in celiac children lend support to the gluten-lectin theory of celiac disease.

Author FÂalth-Magnusson K; Magnusson KE

Address Department of Pediatrics, LinkÂoping University, Sweden.

Source Pediatr Allergy Immunol, 1995 May, 6:2, 98-102

 

Abstract Lectins recognize carbohydrate moities of glycoproteins and glycolipids, and can elicit several biological effects, including cell agglutination, cell activation and mitogenesis. According to the gluten-lectin theory, celiac lesions represent a response to a toxic lectin, putatively wheat germ agglutinin (WGA). In this study we compared the serum antibody levels IgA, IgG and IgM to WGA and to gliadin in children under investigation for celiac disease (CD), as compared to reference children. We found that the levels of IgA and IgG to WGA as well as gliadin were significantly higher in celiac children on a gluten-containing diet, compared to children on gluten-free diet and reference children. These findings lend support to the concept that WGA is a biologically significant component of gluten. Since WGA can mimic the effects of epidermal growth factor (EGF) at the cellular level, we hypothesize that the crypt hyperplasia seen in celiac children could be due to a mitogenic response induced by WGA.

Reversal of osteopenia with diet in adult coeliac disease.

Author Valdimarsson T; LÂofman O; Toss G; StrÂom M

Address Department of Internal Medicine, University Hospital of LinkÂoping, Sweden.

Source Gut, 1996 Mar, 38:3, 322-7

 

Abstract To evaluate the effects of a gluten free diet on bone mineral density in untreated adult patients with coeliac disease, 63 patients (17-79 years, 35 women) were examined at diagnosis and after one year taking a gluten free diet. Bone mineral density was measured in the forearm using single photo absorptiometry and in the lumbar spine, femoral neck, and trochanter using dual energy x ray absorptiometry. The values for each patient were compared with those of 25 healthy controls, matched for sex, age, and menopausal state. Before being given a gluten free diet bone mineral density in the total group was reduced at all sites (p < 0.001). Age adjusted bone mineral density was inversely correlated with age. During the first year taking a gluten free diet bone mineral density increased at all sites (p < 0.01). This was seen in patients of all ages and in patients who were without symptoms of malabsorption (weight loss or diarrhoea) before treatment. Low bone mineral density in patients with untreated coeliac disease increases rapidly when treatment with a gluten free diet is followed. These findings emphasise the importance of early diagnosis and treatment in all patients with coeliac disease.

Detection of low bone mineral density by dual energy x ray absorptiometry in unsuspected suboptimally treated coeliac disease.

Walters JR; Banks LM; Butcher GP; Fowler CR

 Gut, 1995 Aug, 37:2, 220-4

Abstract

Patients with coeliac disease may present with calcium malabsorption but it is unclear whether this results in longterm impairment of bone mineralisation. Dual energy x ray absorptiometry (DXA) was used to study bone mineral density in 34 asymptomatic coeliac disease patients, treated with a gluten free diet for at least two years, and also in 10 newly diagnosed or untreated patients. As expected, untreated patients had low bone mineral density in all regions. In the 29 treated female coeliac disease patients, overall mean values for age adjusted bone mineral density expressed as Z scores were normal although there were many patients with low values, particularly of the lumbar spine and total body. Scores in the postmenopausal patients were significantly worse than in the premenopausal patients and low mean Z scores were found in the five treated male patients. The subjects who had reduced bone mineral density could not be predicted clinically but, despite being asymptomatic, were more likely to have subtotal or partial villous atrophy on small intestinal biopsy (p < 0.0275). In conclusion, although many treated coeliac disease patients have normal bone mineral density, suboptimally treated and newly diagnosed or untreated patients have osteopenia. To reduce the risk of osteoporotic fractures, it is recommended that bone mineral density be measured in all treated coeliac disease patients and those with osteopenia have a repeat intestinal biopsy to assess disease activity.

The gut as a lymphoepithelial organ: the role of intestinal epithelial cells in mucosal immunity.

Author TlaskalovÆa-HogenovÆa H; FarrÆe-Castany MA; StÅepÆankovÆa R; KozÆakovÆa H; TuÅckovÆa L; Funda DP; Barot R; Cukrowska B; et al

Address Department of Immunology and Gnotobiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.

Source Folia Microbiol (Praha), 1995, 40:4, 385-91

 

Abstract Mucosal surfaces covered by a layer of epithelial cells represent the largest and most critical interface between the organism and its environment. The barrier function of mucosal surfaces is performed by the epithelial layer and immune cells present in the mucosal compartment. As recently found, epithelial cells, apart from their participation in absorptive, digestive and secretory processes perform more than a passive barrier function and are directly involved in immune processes. Besides the well known role of epithelial cells in the transfer of polymeric immunoglobulins produced by lamina propria B lymphocytes to the luminal content of mucosals (secretory Igs), these cells were found to perform various other immunological functions, to interact with other cells of the immune system and to induce an efficient inflammatory response to microbial invasion: enzymic processing of dietary antigens, expression of class I and II MHC antigens, presentation of antigens to lymphocytes, expression of adhesive molecules mediating interaction with intraepithelial lymphocytes and components of extracellular matrix, production of cytokines and probable participation in extrathymic T cell development of intraepithelial lymphocytes. All these functions were suggested to influence substantially the mucosal immune system and its response. Under immunopathological conditions, e.g. during infections and inflammatory bowel and celiac diseases, both epithelial cells and intraepithelial lymphocytes participate substantially in inflammatory reactions. Moreover, enterocytes could become a target of mucosal immune factors. Mucosal immunosurveillance function is of crucial importance in various pathological conditions but especially in the case of the most frequent malignity occurring in the intestinal compartment, i.e. colorectal carcinoma. Proper understanding of the differentiation processes and functions of epithelial cells in interaction with other components of the mucosal immune system is therefore highly desirable.

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

Author Troncone R; Greco L; Mayer M; Mazzarella G; Maiuri L; Congia M; Frau F; De Virgiliis S; Auricchio S

Address Department of Pediatrics, University Federico II, Naples, Italy.

Source Gastroenterology, 1996 Aug, 111:2, 318-24

 

Abstract 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.