Population-based screening for celiac disease reveals that the majority of patients are undiagnosed and improve on a gluten-free diet.

The impact of a gluten-free diet (GFD) on screen-detected celiac disease (CD) is currently ambiguous. We aimed to identify the population-based prevalence of undiagnosed adult CD and examine the impact of a GFD on screen-detected CD. In total, 12,981 adults participated in a population-based health study in Tromsø, Norway. Participants with increased levels of anti-tissue transglutaminase-2 IgA or anti-deamidated gliadin peptide IgG were invited to undergo gastroduodenoscopy with both histological and immunohistochemical examination of small-bowel biopsies. The prevalence of previously diagnosed CD was 0.37%. Additionally, the prevalence of previously undiagnosed CD was 1.10%. Thus, 1.47% of the population had CD, of whom 75% were previously undiagnosed. A GFD resulted in significant improvements in overall gastrointestinal symptoms, diarrhea, and health-related quality of life, with reduced abdominal discomfort (76%) and improved levels of energy (58%). The large majority of patients with adult CD were undiagnosed and benefited from a GFD with reduced gastrointestinal symptoms and improved health-related quality of life. In clinical practice, there should be a low threshold for CD testing even in the absence of abdominal complaints because most adult patients appear to consider their symptoms a part of their normal state and therefore remain untested and undiagnosed.Trial registration: Clinical Trials. Gov Identifier: NCT01695681.

Epitope mapping of anti-amelogenin IgG in untreated celiac children.

Children with untreated celiac disease (CeD) may develop enamel defects, and children with severe CeD have significantly increased levels of IgG to amelogenin, which may interfere with normal amelogenesis depending on which epitope(s) they bind. Children with untreated CeD (n = 42), for whom CeD had been confirmed either by biopsy (n = 17, cohort 1) or by the presence of particularly high serum levels of anti-transglutaminase 2 (TG2) IgA (n = 25, cohort 2), were selected from 146 children with CeD, and 10 controls were selected from 34 children who did not have CeD. Samples from these 52 children were used for detailed IgG anti-amelogenin, X isoform (AMELX) epitope mapping using 31 overlapping, 10-22mer peptides in ELISA. Although sera from both groups showed reactivity to peptides containing sequences from the N and C terminus of AMELX, sera from children with CeD reacted more strongly to peptides from the central region (amino acids 75-150) containing both a binding site for transforming growth factor-ß (TGF-ß), as well as the enzymatic cleavage sites for matrix metalloproteinase-20 and for kallikrein-4. Antigen-specific extraction revealed that only IgG to the central region cross-reacted to gliadin. Thus, cross-reactive anti-gliadin/amelogenin IgG may affect normal amelogenesis by interfering with enzymatic degradation, proper folding, and/or TGF-ß signaling in children with untreated CeD.

Ancestral Wheat Types Release Fewer Celiac Disease Related T Cell Epitopes than Common Wheat upon Ex Vivo Human Gastrointestinal Digestion.

Celiac disease (CeD) is an autoimmune enteropathy triggered by immunogenic gluten peptides released during the gastrointestinal digestion of wheat. Our aim was to identify T cell epitope-containing peptides after ex vivo digestion of ancestral (einkorn, spelt and emmer) and common (hexaploid) wheat (Fram, Bastian, Børsum and Mirakel) using human gastrointestinal juices. Wheat porridge was digested using a static ex vivo model. Peptides released after 240 min of digestion were analyzed by liquid chromatography coupled to high-resolution mass spectrometry (HPLC-ESI MS/MS). Ex vivo digestion released fewer T cell epitope-containing peptides from the ancestral wheat varieties (einkorn (n = 38), spelt (n = 45) and emmer (n = 68)) compared to the common wheat varieties (Fram (n = 72), Børsum (n = 99), Bastian (n = 155) and Mirakel (n = 144)). Neither the immunodominant 33mer and 25mer α-gliadin peptides, nor the 26mer γ-gliadin peptide, were found in any of the digested wheat types. In conclusion, human digestive juice was able to digest the 33mer and 25mer α-gliadin, and the 26mer γ-gliadin derived peptides, while their fragments still contained naive T cell reactive epitopes. Although ancestral wheat released fewer immunogenic peptides after human digestion ex vivo, they are still highly toxic to celiac patients. More general use of these ancient wheat variants may, nevertheless, reduce CeD incidence.

Epitope mapping of anti-amelogenin IgA in coeliac disease.

Previously we detected increased levels of IgA to the enamel matrix protein amelogenin in children with untreated coeliac disease (CeD). The biological impact of autoantibodies to amelogenin may depend on which part of the amelogenin (epitopes) they bind. Sera or blood samples from 146 untreated children with CeD from two different cohorts and 25 non-CeD control children were tested for IgA anti-amelogenin (Emdogain) reactivity. The 32 CeD children and six controls with the highest reactivity were selected for detailed IgA anti-amelogenin (AMELX) epitope mapping using 31 overlapping, 10-22mer peptides in ELISA. The dominating reactivity were to six peptides in a 75-amino-acid (aa)-long central segment (aa 75-150) containing enzymatic cleavage sites for matrix metalloproteinase 20 (MMP-20) and kallikrein-related peptidase 4 (KLK-4) and to two N-terminal peptides (aa 13-41) included in the tyrosine-rich amelogenin peptide fragment, which is important for self-assembly. Only two of the six control children reacted to single, but different peptides. Solid-phase extraction with gliadin- and Emdogain-coated Sepharose revealed a gliadin cross-reactive central region and a putative conformation-dependent, apparently non-cross-reactive N-terminal region. High IgA anti-amelogenin reactivity may interfere with normal amelogenesis by inhibiting amelogenin self-assembly, amelogenin-hydroxyapatite interaction, and/or enzymatic degradation.

Amelogenin specific IgA and IgG in children with untreated coeliac disease.

Children with untreated coeliac disease (CD) may develop enamel defects. Moreover, children with untreated CD have increased serum levels of gliadin reactive IgG, which may cross-react to amelogenin. The aim of this study was to investigate reactivity of anti-gliadin IgA and IgG to amelogenin in children with untreated CD. Blood samples from patients with CD (n = 75) and from disease controls (n = 24) were analysed for IgA and IgG reactivities to amelogenin (Emdogain) and to gliadin by ELISA. Whereas children with CD had statistically significantly higher serum levels of anti-amelogenin IgA, only those with the most severe CD (Marsh 3c) had significantly higher anti-amelogenin IgG immune reactivity than the disease controls. Western blotting confirmed that the IgA and IgG immune reactivity was to the amelogenin-specific bands in Emdogain and to a 22-kDa human recombinant amelogenin. Cross-inhibition studies revealed that the anti-amelogenin immune reactivity was not only caused by anti-gliadin cross-reactivity but also included amelogenin selective immune reactivity. Some controls had high levels of anti-amelogenin IgA and IgG, similar to children with CD. Thus, anti-amelogenin IgA and IgG may not only be involved in the aetiology of CD-associated enamel defects but may also interfere with enamel maturation in non-coeliac children.

Epidermal growth factor (EGF) receptor-ligand based molecular staging predicts prognosis in head and neck squamous cell carcinoma partly due to deregulated EGF- induced amphiregulin expression.

BACKGROUND: Increased expression of epidermal growth factor receptor (EGFR) and its ligands is associated with poor prognosis and chemoresistance in many carcinoma types, but its role in head and neck squamous cell carcinoma (HNSCC) is unclear. Our aim was to clarify whether mRNA expression of EGFR-ligands was linked to prognosis and cisplatin resistance, and if so, which ligand was most important and how was the expression regulated. METHODS: To examine the prognostic effect of EGFR-ligand expression, we analyzed tumorous mRNA expression in 399 HNSCC patients. The intracellular signaling pathways controlling epidermal growth factor (EGF)-induced amphiregulin (AREG) expression were examined in three oral squamous cell carcinoma (OSCC) cell lines. Effect of AREG on cisplatin resistance was examined by viability assays in four-, and by association in 11 OSCC cell lines. RESULTS: The patients were divided into five groups according to the median mRNA expression levels of four EGFR ligands, i.e. AREG, EGF, heparin-binding EGF-like growth factor (HBEGF) and beta-cellulin (BTC). The number of increased-expressed EGFR-ligands were progressively correlated to five-year survival, even in advanced TNM-stage IV patients, where five-year mortality increased from 26 % if tumor expressed none to one EGFR-ligand, to 45 % in three to four ligand expressing tumors. Thus, staging the tumor according to these EGFR-ligand mRNA expression pattern completely out performed TNM staging in predicting prognosis. Multivariate analysis identified AREG as the dominating predictor, and AREG was overexpressed in OSCC compared to tumors from other sites. Both EGF and HBEGF stimulation induced strong AREG increase in OSCC cell lines, which was partially mediated by the extracellular signal-regulated kinase 1/2 pathway, and negatively regulated by p38, c-Jun N-terminal kinase, and phosphoinositide-3 kinase. Although increased AREG mRNA expression predicted unfavorable prognosis in platinum treated HNSCC patients, AREG did not mediate cisplatin resistance in the OSCC cell lines. CONCLUSIONS: Increased tumorous mRNA expression of four EGFR ligands was progressively associated with poor prognosis in HNSCC. Thus, EGFR-ligands mRNA expression pattern may be a new prognostic biomarker. The tightly regulated EGF-induced AREG mRNA expression was partly lost in the OSCC cell lines and restoring its regulation may be a new target in cancer treatment. TRIAL REGISTRATION: Not applicable as the clinical data of the 498 HNSCC patients and their mRNA expression profiles were collected from the open TCGA database: http://cancergenome.nih.gov/cancersselected/headandneck .

Increased interleukin-6 expression is associated with poor prognosis and acquired cisplatin resistance in head and neck squamous cell carcinoma.

Increased expression of interleukin 6 (IL-6) is associated with poor prognosis and chemoresistance in many different carcinomas, but its role in head and neck squamous cell carcinoma (HNSCC) is still unsettled. Analyzing tumorous mRNA expression data from 399 HNSCC patients revealed that high IL-6 expression predicted poor prognosis. Similar tendency was observed in platinum treated patients, suggesting an IL-6 associated cisplatin resistance. IL-6 increase was also found in two in-house acquired cisplatin­resistant HNSCC cell lines (both basaloid and conventional squamous cell carcinoma) by using microarray analysis. However, although the in-house acquired cisplatin-resistant cell lines had higher basal and markedly increased cisplatin-induced IL-6 expression, IL-6 did not mediate the cisplatin resistance as neither exogenous IL-6 nor IL-6R/gp130 inhibitors affected cisplatin sensitivity. Moreover, the IL-6/STAT3 pathway was impaired in the resistant cell lines, partly due to decreased IL-6R expression. Thus, high IL-6 expression correlated to poor prognosis and acquired cisplatin resistance, but it did not mediate cisplatin resistance in the HNSCC cell lines.

High nuclear SOX2 expression is associated with radiotherapy response in small (T1/T2) oral squamous cell carcinoma.

OBJECTIVE: Expression of the stem cell transcription factor SOX2 is often used to imply stemness and poor prognosis in cancer. However, its role in oral squamous cell carcinoma (OSCC) is not fully elucidated. MATERIAL AND METHODS: Tumour tissues from 62 patients with primary, node negative and non-metastatic OSCCs were used to evaluate SOX2 expression by immunohistochemistry. The results were correlated to clinicopathology, treatment and disease recurrences. RESULTS: The majority of the OSCCs (88%) expressed SOX2. Patients with higher nuclear SOX2 staining intensity in the invasive front compared to the adjacent normal epithelium, had a remarkable longer disease-free period if they received adjuvant post-operative radiotherapy (P = 0.001). This was in particular evident for highly differentiated OSCCs, as none of the high SOX2-expressing tumours reoccurred in contrast to all low SOX2-expressing OSCCs. CONCLUSIONS: High nuclear SOX2 expression in the invasive front was associated with dramatic longer disease-free period than low SOX2-expressing carcinomas after post-operative radiotherapy in small OSCCs. The result suggested that high nuclear SOX2 expression at the invasive front may predict radiosensitivity.

Epidermal growth factor-induced cyclooxygenase-2 expression in oral squamous cell carcinoma cell lines is mediated through extracellular signal-regulated kinase 1/2 and p38 but is Src and nuclear factor-kappa B independent.

The intracellular signalling cascade(s) mediating epidermal growth factor (EGF)-induced cyclooxygenase-2 (COX-2) expression is poorly defined in oral carcinomas. Investigation of two different oral squamous cell carcinoma (OSCC) cell lines with high EGF-induced COX-2 expression revealed, however, that this expression was dependent on two mitogen-activated protein kinase (MAPK) pathways [extracellular signal-regulated kinase 1/2 (ERK1/2) and p38] because combined inhibition of these pathways was needed to abolish EGF-induced COX-2 expression. Surprisingly, inhibition of phosphoinositide-3 kinase (PI3K) increased EGF-induced COX-2 expression in the basaloid OSCC cell line (C12), suggesting a PI3K-controlled, inhibitory COX-2-regulating pathway. Neither the transcription factor nuclear factor-kappaB (NF-kappaB), nor Src, was involved in EGF-induced COX-2 expression. The results suggest that EGF-induced COX-2 expression is regulated by several pathways, and emphasizes that individual tumors use different strategies for intracellular signalling.

c-Jun N-terminal kinase negatively regulates epidermal growth factor-induced cyclooxygenase-2 expression in oral squamous cell carcinoma cell lines.

Epidermal growth factor (EGF)-induced cyclooxygenase-2 (COX-2) expression in squamous cell carcinomas is mediated through the extracellular signal-regulated kinase 1/2 and p38 pathways. Examination of a basaloid and a conventional oral squamous cell carcinoma cell line revealed that inhibition of c-Jun N-terminal kinase (JNK) with SP600125 increased EGF-induced (but not basal) COX-2 transcription 1.5-1.9-fold in extracellular signal-regulated kinase 1/2 and p38 pathway-dependent manners. Although JNK may phosphorylate the cyclosporine A-sensitive transcription factor, nuclear factor of activated T cells c3, it was seemingly not involved because cyclosporine A did not reduce EGF-induced COX-2 expression. Thus, JNK negatively regulated EGF-induced extracellular signal-regulated kinase 1/2 and/or p38-mediated COX-2 transcription, presumably through activating an unidentified phosphatase.

Casein-specific immunoglobulins in cow's milk allergic patient subgroups reveal a shift to IgA dominance in tolerant patients.

Differences in casein-specific immunoglobulin (Ig) G-subclass and IgA serum levels between reactive and tolerant patients may hint at the immunopathogenesis during tolerance development in cow's milk allergy (CMA). alpha-, beta- and kappa-casein-specific IgG(1), IgG(4), IgE and IgA serum levels were compared in clinically reactive and tolerized IgE-mediated (n = 15) and non-IgE-mediated (n = 14) CMA with delayed gastrointestinal symptoms, using enzyme-linked immunosorbent assay (ELISA) and immunoblot techniques. The median anti-casein IgE levels in clinically reactive IgE-mediated CMA patients (n = 9) were 140- to 180-fold higher than in tolerized patients (n = 6) and 160- to 200-fold higher than in controls (n = 10). Median alpha-, beta- and kappa-casein-specific IgG(1) and IgG(4) levels were nine- to 60-fold higher in reactive patients and five- to 60-fold in tolerized patients. Clinical tolerance in IgE-mediated CMA was thus associated with decreased casein-specific IgE, IgG(4) and IgG(1), whereas serum IgA anti-alpha -, beta- and kappa-casein remained practically unaltered. Tolerized cow's milk protein (CMP)-sensitive atopic dermatitis had, in particular, decreased kappa-casein-specific IgG(1) levels, compared with clinically reactive patients. The ELISA levels to immunoblot correlation profile for the alpha-, beta- and kappa-casein-specific IgE suggested that the IgE-mediated CMA patients predominantly reacted to tertiary alpha- and beta-casein epitopes whereas the IgE in non-IgE-mediated patients reacted to linearized alpha-, beta- and kappa-casein epitopes. Clinical tolerance in non-IgE-mediated CMA patients (n = 9) was associated with a four- to 10-fold decrease in casein-specific IgE levels, accompanied by a five- to eightfold decrease in IgG(1) and five- to 60-fold decrease in IgG(4) levels, whereas casein-specific IgA levels remained unaltered. Thus, tolerance in both patient groups was characterized by a generalized decreased humoral immune response to caseins, which induced a functional shift to IgA dominance.

Memory T cell proliferation in cow's milk allergy after CD25+ regulatory T cell removal suggests a role for casein-specific cellular immunity in IgE-mediated but not in non-IgE-mediated cow's milk allergy.

BACKGROUND: Previously reported increased lymphocyte proliferative responses in cow's milk allergy (CMA) may have been influenced by the lipopolysaccharides (LPS) which contaminate most commercial cow's milk protein (CMPs). Moreover, peripheral blood mononuclear cells (PBMC) contain both B cells, CD45RA+ naïve T cells, CD25+ regulatory T cells (Tregs) in addition to antigen-specific CD45RA- memory T cells. METHODS: PBMC from clinically reactive and tolerised patients with IgE- and non-IgE-mediated CMA were depleted of CD45RA+ T cells and putative CD25+ Tregs. The proliferative index to LPS-depleted alpha-, beta- and kappa-casein and beta-lactoglobulin was compared in the memory T-cell-enriched, Treg-depleted PBMC and in bulk PBMC. RESULTS: Clinically reactive IgE-mediated CMA patients had increased responses to caseins only. Tolerised patients, particularly those with atopic dermatitis, had decreased responses to kappa-casein which were restored after Treg depletion. Interleukin-4 and interferon-gamma were generally not detected in the culture supernatants. No differences were seen between reactive and tolerant delayed non-IgE-mediated CMA patients. CONCLUSIONS: Proliferative responses to alpha-, beta- and kappa-caseins (but not beta-lactoglobulin) were observed in clinically reactive IgE-mediated CMA patients only. A markedly decreased proliferative response to kappa-casein in tolerised IgE-mediated CMA patients with atopic dermatitis, which was abrogated by Treg depletion, suggested a role for kappa-casein in tolerance induction. Non-IgE-mediated CMA patients had no increased proliferative response to any milk proteins.

Changes in humoral responses to beta-lactoglobulin in tolerant patients suggest a particular role for IgG4 in delayed, non-IgE-mediated cow's milk allergy.

The major cow's milk allergen beta-lactoglobulin (beta-LG) is relatively resistant to enzymatic degradation and may therefore be involved in non-immunoglobulin (Ig)E-mediated cow's milk allergy (CMA) with delayed gastrointestinal symptoms. Serum levels of beta-LG-specific IgG(1), IgG(4), IgE, and IgA were compared in clinically reactive and tolerized IgE-mediated and non-IgE-mediated CMA with delayed gastrointestinal symptoms (n = 29) and controls (n = 10). Tolerance was associated with decreased beta-LG-specific IgE, IgG(1), and IgG(4) levels in both patient groups. However, the significantly increased beta-LG-specific IgG(4) levels in clinically reactive non-IgE-mediated CMA patients, and its median 36-fold reduction in tolerant patients, suggested a possible immunopathological role for IgG(4) in delayed CMA. Similarly, the significantly increased beta-LG-specific IgE levels in IgE-mediated CMA patients were decreased 44-fold in tolerant patients. The tolerant patients had apparently shifted the humoral immune response from a beta-LG-specific IgE- and/or IgG(4)-dominated immune response to an IgA-dominated immune response as the IgA/IgE or IgA/IgG(4) ratios increased 90- and 15-fold in tolerant IgE-mediated-, and non-IgE-mediated CMA patients, respectively. Thus, the marked difference in beta-LG-specific Ig ratios suggested a tolerance-induced inhibition of a Th(2)-type of immune response with significantly increased IgA dominance in both CMA patient groups.

The B-cell system in inflammatory bowel disease.

Secretory immunity is the best-defined part ot the mucosal immune system. This adaptive humoral defense mechanism depends on a fine-tuned cooperation between secretory epithelia and local plasma cells. Such mucosal immunocytes produce preferentially dimers and larger polymers of immunoglobulin A (collectively called pIgA), which contain J chain and therefore can bind to the epithelial secretory component (SC). This transmembrane glycoprotein functions as pIg receptor (pIgR) that also translocates pentameric IgM to the epithelial surface. B cells with a high level of J-chain expression and pIg-pIgR interactions at mucosal effector sites are thus necessary for the generation of secretory antibodies (SIgA and SIgM). Secretory antibodies perform immune exclusion in a first-line defense, thereby counteracting microbial colonization and mucosal penetration of soluble antigens. However, local production of pIgA is significantly down-regulated in inflammatory bowel disease (IBD), as revealed by strikingly decreased J-chain expression. Although the total increase of the immunocyte population in IBD lesions probably compensates for the relatively reduced pIgA production, decreased pIgR/SC expression in regenerating and dysplastic epithelium signifies that the SIgA system is topically deficient. There is, moreover, a significant shift from IgA2 to IgA1 production, the latter subclass being less resistant to proteolytic degradation. These changes--together with activation of mucosal macrophages and a dramatic increase of IgG-producing cells--may reflect local establishment of a second defense line which, however, is unsuccessful in its attempt to eliminate antigens derived from the indigenous microbial flora. Such a 'frustrated' local humoral immune system results in altered immunological homeostasis and jeopardized mucosal integrity. Complement activation observed in relation to epithelium-bound IgG1 in ulcerative colitis indicates, moreover, that the surface epithelium is subjected to immunological attack by an autoimmune reaction. These luminal deposits regularly contain terminal cytotoxic complement, and often also C3b as a sign of persistent activation. Comparison of identical twins, discordant with regard to ulcerative colitis, suggests that the markedly skewed local IgG1 response seen in this IBD entity may be genetically determined. The initial event(s) eliciting B-cell driven immunopathology in IBD remains unknown. Abrogation of oral tolerance to certain antigens from commensal bacteria has been suggested as a putative early mechanism, and lymphoid neogenesis and hyperplasia in the lesions most likely signify massive microbial overstimulation of the local B-cell system. Such ectopic lymphoid microcompartments may contribute substantially to the proinflammatory systemic-type of B-cell responses occurring in established IBD lesions.

Bronchial mast cells are the dominating LTC4S-expressing cells in aspirin-tolerant asthma.

The increased bronchial production of leukotriene C4 (LTC4) in asthma is assumed to derive from infiltrating eosinophils expressing LTC4-synthase (LTC4S). Multicolor immunohistofluorescence examination of bronchial cryosections from 30 treated, untreated, or bronchial antigen-provoked aspirin-tolerant individuals with asthma and nine control subjects revealed that the dominating LTC4S-expressing cells were mast cells (> 80%), and not eosinophils. Whereas 95% of the mast cells expressed high levels of LTC4S, only 8-27% of the eosinophils expressed low levels. Image analysis revealed a significantly higher LTC4S expression levels in mast cells than in eosinophils. The bronchial mRNA levels for LTC4S did not correlate with the densities of LTC4S-positive eosinophils or mast cells. Treated individuals with asthma with more than 12% reversibility had significantly higher density of LTC4S-positive mast cells than those with less reversibility, and it correlated significantly with reduction in lung function (FEV1-predicted), both before and after salbutamol inhalation. Thus, mucosal mast cells, and not eosinophils, were the dominating LTC4S-containing cells in both untreated and treated aspirin-tolerant asthma. The density of LTC4S-positive mast cells correlated, moreover, with both the reduction in lung function and the degree of reversibility in treated asthma.

Cancer incidence in a population-based cohort of individuals hospitalized with celiac disease or dermatitis herpetiformis.

BACKGROUND & AIMS: Studies of cancer risk in celiac disease (CD) or dermatitis herpetiformis (DH) indicate increased risks for malignant lymphoma and occasionally other neoplasms, but are characterized by small numbers, lack of systematic cancer assessment, and subjects identified from referral institutions. METHODS: By using Swedish population-based inpatient and cancer registry data, we followed-up 12,000 subjects with CD or DH, and evaluated cancer incidence by using standardized incidence ratios (SIR). RESULTS: Adults (but not children and adolescents) with CD had an elevated overall risk for cancer (SIR = 1.3) that declined with time and eventually reached unity. Elevated risks were found for malignant lymphomas, small-intestinal, oropharyngeal, esophageal, large intestinal, hepatobiliary, and pancreatic carcinomas. The excess occurrence of malignant lymphomas was confined to adults, decreased with time of follow-up evaluation, and decreased over successive calendar periods. Decreased risks were found for breast cancer. Subjects with DH had a slightly increased overall cancer risk (SIR = 1.2) owing to excesses of malignant lymphoma and leukemia, but no increases of gastrointestinal carcinomas. CONCLUSIONS: Albeit increased, the relative risks for lymphomas and gastrointestinal cancers in this study are lower (and declining) than in most previous reports. The overall cancer risk is only moderately increased, and nonelevated during childhood and adolescence.