Alterations of Inflammatory and Matrix Production Indices in Celiac Disease With Low Bone Mass on Long-term Gluten-free Diet.

BACKGROUND: A clinically meaningful impairment of bone mass secondary to malabsorption is frequent in untreated celiac disease. In adult patients, a rigorous gluten-free diet (GFD) significantly improves, but does not always normalize, bone mineral density (BMD). The reason for this marginal response is unclear. Accordingly, we evaluated the role of both local and systemic factors for bone loss in celiac patients on long-term GFD. STUDY: In a prospective cohort, 22 patients with low lumbar and/or femoral BMD and 22 with normal BMD underwent bone and mineral metabolism evaluation: we tested calcium, phosphate, parathyroid hormone, and vitamin D; telopeptide of type I collagen, a bone resorption index; propeptide of type I procollagen, a bone neoformation index; receptor antagonist of NF-kB ligand, an osteoclast-stimulating factor; osteoprotegerin (OPG), a decoy receptor for RANKL. Sunlight exposure and physical exercise were measured. RESULTS: Patients with bone loss showed prevalently osteopenia, severe osteoporosis was rare. In comparison with normal BMD patients, they showed higher serum OPG, telopeptide, and lower serum propeptide, suggesting an increased bone turnover. Lumbar T-score was negatively correlated with OPG, telopeptide and RANKL and positively with propeptide. Propeptide was negatively correlated with OPG and telopeptide. OPG was positively correlated with telopeptide. CONCLUSIONS: The persistent activation of inflammation should be considered the main pathophysiological mechanism for bone defect in celiac disease patients with bone loss on long-term GFD. High levels of OPG, an attempt at protective mechanism, and low levels of propeptide of type I procollagen, reflecting an insufficient matrix production, characterize this subgroup of patients.

Pathogenesis, diagnosis and treatment of anaemia in immune-mediated gastrointestinal disorders.

Immune-mediated disorders affecting the gastrointestinal (GI) tract may compromise GI integrity, interfere with the absorption of nutrients and cause bleeding and inflammation. All these features contribute to the pathogenesis of anaemia, the most prevalent extra-intestinal manifestation of immune-mediated GI disorders. Anaemia is most commonly due to iron deficiency and/or inflammation, but vitamin deficiencies and, more infrequently, autoimmune haemolysis or drug-induced myelosuppression can be involved. Here we address several issues related to the differential diagnosis and treatment of anaemia in immune-mediated GI disorders, giving particular relevance to the problem of iron deficiency anaemia associated with inflammation. It is emphasized how, in most cases, anaemias due to iron or vitamin deficiencies are best treated by parenteral administration of the deficient factor(s), and how the available high dose intravenous (IV) iron formulations can reduce ambulatory and social costs of IV iron supplementation, while improving patient's compliance to treatment. Actual and future treatment possibilities for anaemia of inflammation, involving the use of erythropoiesis stimulating agents, biologicals and hepcidin inhibitors are discussed.

Mongersen, an oral SMAD7 antisense oligonucleotide, and Crohn's disease.

BACKGROUND: Crohn's disease-related inflammation is characterized by reduced activity of the immunosuppressive cytokine transforming growth factor ß1 (TGF-ß1) due to high levels of SMAD7, an inhibitor of TGF-ß1 signaling. Preclinical studies and a phase 1 study have shown that an oral SMAD7 antisense oligonucleotide, mongersen, targets ileal and colonic SMAD7. METHODS: In a double-blind, placebo-controlled, phase 2 trial, we evaluated the efficacy of mongersen for the treatment of persons with active Crohn's disease. Patients were randomly assigned to receive 10, 40, or 160 mg of mongersen or placebo per day for 2 weeks. The primary outcomes were clinical remission at day 15, defined as a Crohn's Disease Activity Index (CDAI) score of less than 150, with maintenance of remission for at least 2 weeks, and the safety of mongersen treatment. A secondary outcome was clinical response (defined as a reduction of 100 points or more in the CDAI score) at day 28. RESULTS: The proportions of patients who reached the primary end point were 55% and 65% for the 40-mg and 160-mg mongersen groups, respectively, as compared with 10% for the placebo group (P<0.001). There was no significant difference in the percentage of participants reaching clinical remission between the 10-mg group (12%) and the placebo group. The rate of clinical response was significantly greater among patients receiving 10 mg (37%), 40 mg (58%), or 160 mg (72%) of mongersen than among those receiving placebo (17%) (P=0.04, P<0.001, and P<0.001, respectively). Most adverse events were related to complications and symptoms of Crohn's disease. CONCLUSIONS: We found that study participants with Crohn's disease who received mongersen had significantly higher rates of remission and clinical response than those who received placebo. (Funded by Giuliani; EudraCT number, 2011-002640-27.).

Intestinal T-cell lymphoma with enteropathy-associated T-cell lymphoma-like features arising in the setting of adult autoimmune enteropathy.

Enteropathy-associated T-cell lymphoma is regarded as a dismal, late complication of coeliac disease, though a single case of T-cell lymphoma with such features arising in the setting of autoimmune enteropathy of the adult has been reported to date. We aim to describe the case of a 41-year-old woman complaining of severe malabsorption syndrome, who was diagnosed with autoimmune enteropathy based on the presence of flat intestinal mucosa unresponsive to any dietary restriction and positivity for enterocyte autoantibodies. Steroid therapy led to a complete recovery of both mucosal and clinical findings over 12 years, when disease relapse was accompanied by the appearance of monoclonal rearrangement of T-cell receptor-γ and peculiar T-cell phenotypic abnormalities, leading to a rapid transition to an overt T-cell lymphoma with features of the enteropathy-associated subtype. Despite intensive treatment, the patient developed cerebral metastasis and died 9 months later. Our case enhances the concept of enteropathy-associated T-cell lymphoma as a disease that may arise in the setting of enteropathies other than coeliac disease, thus representing a heterogeneous entity. Moreover, our observations support the need of a close follow-up of these patients, coupled with comprehensive characterization of mucosal biopsies.

The Relationship Between Child Mortality Rates and Prevalence of Celiac Disease.

OBJECTIVES: Some evidence suggests that prevalence of celiac disease in the general population is increasing over time. Because the prognosis of celiac disease was a dismal one before discovering the role of gluten, our aim was to investigate a possible relationship between children under-5 mortality rates and prevalence rates of celiac disease. METHODS: Thanks to a literature review, we found 27 studies performed in 17 different countries describing the prevalence of celiac disease in schoolchildren; between 1995 and 2011, 4 studies were performed in Italy. A meta-analysis of prevalence rates was performed. Prevalence was compared between specific country under-5 mortality groups, publication year, and age. RESULTS: In the last decades, under-5 mortality rates have been decreasing all over the world. This reduction is paralleled by an increase of the prevalence of celiac disease. The Spearman correlation coefficient was -63%, 95% confidence interval -82% to -33% (P < 0.001). So, the higher the mortality rate, the lower the prevalence of CD. This finding is confirmed by the meta-analysis of the 4 studies conducted in Italy over time. CONCLUSIONS: The under-5 mortality rate seems to influence the prevalence of celiac disease in the general population. In the near future, the number of patients with celiac disease will increase, thanks to the better environmental conditions that nowadays allow a better survival of children with celiac disease.

High Smad7 sustains inflammatory cytokine response in refractory coeliac disease.

Refractory coeliac disease (RCD) is a form of coeliac disease (CD) resistant to gluten-free diet and associated with elevated risk of complications. Many effector cytokines over-produced in the gut of patients with RCD are supposed to amplify the tissue-destructive immune response, but it remains unclear if the RCD-associated mucosal inflammation is sustained by defects in counter-regulatory mechanisms. The aim of the present study was to determine whether RCD-related inflammation is marked by high Smad7, an intracellular inhibitor of transforming growth factor-ß1 (TGF-ß1 ) activity. Smad7 was evaluated in duodenal biopsy samples of patients with RCD, patients with active CD, patients with inactive CD and healthy controls by Western blotting, immunohistochemistry and real-time PCR. In the same samples, TGF-ß1 and phosphorylated (p)-Smad2/3 were evaluated by ELISA and immunohistochemistry, respectively. Pro-inflammatory cytokine expression was evaluated in RCD samples cultured with Smad7 sense or antisense oligonucleotide. Smad7 protein, but not RNA, expression was increased in RCD compared with active and inactive CD patients and healthy controls and this was associated with defective TGF-ß1 signalling, as marked by diminished p-Smad2/3 expression. TGF-ß1 protein content did not differ among groups. Knockdown of Smad7 in RCD biopsy samples reduced interleukin-6 and tumour necrosis factor-α expression. In conclusion, in RCD, high Smad7 associates with defective TGF-ß1 signalling and sustains inflammatory cytokine production. These results indicate a novel mechanism by which the mucosal cytokine response is amplified in RCD and suggest that targeting Smad7 can be therapeutically useful in RCD.

Small bowel carcinomas in celiac or Crohn's disease: distinctive histophenotypic, molecular and histogenetic patterns.

Non-familial small bowel carcinomas are relatively rare and have a poor prognosis. Two small bowel carcinoma subsets may arise in distinct immune-inflammatory diseases (celiac disease and Crohn's disease) and have been recently suggested to differ in prognosis, celiac disease-associated carcinoma cases showing a better outcome, possibly due to their higher DNA microsatellite instability and tumor-infiltrating T lymphocytes. In this study, we investigated the histological structure (glandular vs diffuse/poorly cohesive, mixed or solid), cell phenotype (intestinal vs gastric/pancreatobiliary duct type) and Wnt signaling activation (ß-catenin and/or SOX-9 nuclear expression) in a series of 26 celiac disease-associated small bowel carcinoma, 25 Crohn's disease-associated small bowel carcinoma and 25 sporadic small bowel carcinoma cases, searching for new prognostic parameters. In addition, non-tumor mucosa of celiac and Crohn's disease patients was investigated for epithelial precursor changes (hyperplastic, metaplastic or dysplastic) to help clarify carcinoma histogenesis. When compared with non-glandular structure and non-intestinal phenotype, both glandular structure and intestinal phenotype were associated with a more favorable outcome at univariable or stage- and microsatellite instability/tumor-infiltrating lymphocyte-inclusive multivariable analysis. The prognostic power of histological structure was independent of the clinical groups while the non-intestinal phenotype, associated with poor outcome, was dominant among Crohn's disease-associated carcinoma. Both nuclear ß-catenin and SOX-9 were preferably expressed among celiac disease-associated carcinomas; however, they were devoid, per se, of prognostic value. We obtained findings supporting an origin of celiac disease-associated carcinoma in SOX-9-positive immature hyperplastic crypts, partly through flat ß-catenin-positive dysplasia, and of Crohn's disease-associated carcinoma in a metaplastic (gastric and/or pancreatobiliary-type) mucosa, often through dysplastic polypoid growths of metaplastic phenotype. In conclusion, despite their common origin in a chronically inflamed mucosa, celiac disease-associated and Crohn's disease-associated small bowel carcinomas differ substantially in histological structure, phenotype, microsatellite instability/tumor-infiltrating lymphocyte status, Wnt pathway activation, mucosal precursor lesions and prognosis.

Abnormal thymic stromal lymphopoietin expression in the duodenal mucosa of patients with coeliac disease.

OBJECTIVE: The short isoform of thymic stromal lymphopoietin (TSLP), a cytokine constitutively expressed by epithelial cells, is crucial in preserving immune tolerance in the gut. TSLP deficiency has been implicated in sustaining intestinal damage in Crohn's disease. We explored mucosal TSLP expression and function in refractory and uncomplicated coeliac disease (CD), a T-cell-mediated enteropathy induced by gluten in genetically susceptible individuals. DESIGN: TSLP isoforms-long and short-and receptors-TSLPR and interleukin (IL)-7Rα-were assessed by immunofluorescence, immunoblotting and qRT-PCR in the duodenum of untreated, treated, potential and refractory patients with CD. The ability of the serine protease furin or CD biopsy supernatants to cleave TSLP was evaluated by immunoblotting. The production of interferon (IFN)-γ and IL-8 by untreated CD biopsies cultured ex vivo with TSLP isoforms was also assessed. RESULTS: Mucosal TSLP, but not TSLPR and IL-7Rα, was reduced in untreated CD and refractory CD in comparison to treated CD, potential CD and controls. Transcripts of both TSLP isoforms were decreased in active CD mucosa. Furin, which was overexpressed in active CD biopsies, was able to cleave TSLP in vitro. Accordingly, refractory and untreated CD supernatants showed higher TSLP-degrading capacity in comparison to treated CD and control supernatants. In our ex vivo model, both TSLP isoforms significantly downregulated IFN-γ and IL-8 production by untreated CD biopsies. CONCLUSIONS: Reduced mucosal TSLP expression may contribute to intestinal damage in refractory and untreated CD. Further studies are needed to verify whether restoring TSLP might be therapeutically useful especially in refractory patients with CD.

Proteolytic cleavage and loss of function of biologic agents that neutralize tumor necrosis factor in the mucosa of patients with inflammatory bowel disease.

BACKGROUND & AIMS: Many patients with inflammatory bowel disease (IBD) fail to respond to anti-tumor necrosis factor (TNF) agents such as infliximab and adalimumab, and etanercept is not effective for treatment of Crohn's disease. Activated matrix metalloproteinase 3 (MMP3) and MMP12, which are increased in inflamed mucosa of patients with IBD, have a wide range of substrates, including IgG1. TNF-neutralizing agents act in inflamed tissues; we investigated the effects of MMP3, MMP12, and mucosal proteins from IBD patients on these drugs. METHODS: Biopsy specimens from inflamed colon of 8 patients with Crohn's disease and 8 patients with ulcerative colitis, and from normal colon of 8 healthy individuals (controls), were analyzed histologically, or homogenized and proteins were extracted. We also analyzed sera from 29 patients with active Crohn's disease and 33 patients with active ulcerative colitis who were candidates to receive infliximab treatment. Infliximab, adalimumab, and etanercept were incubated with mucosal homogenates from patients with IBD or activated recombinant human MMP3 or MMP12 and analyzed on immunoblots or in luciferase reporter assays designed to measure TNF activity. IgG cleaved by MMP3 or MMP12 and antihinge autoantibodies against neo-epitopes on cleaved IgG were measured in sera from IBD patients who subsequently responded (clinical remission and complete mucosal healing) or did not respond to infliximab. RESULTS: MMP3 and MMP12 cleaved infliximab, adalimumab, and etanercept, releasing a 32-kilodalton Fc monomer. After MMP degradation, infliximab and adalimumab functioned as F(ab')2 fragments, whereas cleaved etanercept lost its ability to neutralize TNF. Proteins from the mucosa of patients with IBD reduced the integrity and function of infliximab, adalimumab, and etanercept. TNF-neutralizing function was restored after incubation of the drugs with MMP inhibitors. Serum levels of endogenous IgG cleaved by MMP3 and MMP12, and antihinge autoantibodies against neo-epitopes of cleaved IgG, were higher in patients who did not respond to treatment vs responders. CONCLUSIONS: Proteolytic degradation may contribute to the nonresponsiveness of patients with IBD to anti-TNF agents.

Olmesartan-associated enteropathy: new insights on the natural history? Report of two cases.

INTRODUCTION: The association between olmesartan and an enteropathy histologically indistinguishable from untreated celiac disease has recently been described. However, pathogenetic mechanisms leading to villous atrophy, prevalence, natural history and genetic background of this condition have not yet been defined. PATIENTS: We describe here two cases of olmesartan-associated enteropathy and discuss some aspects of the natural history of this condition. RESULTS: In both patients, an infectious episode seems to have triggered the severe malabsorption syndrome which led them to hospitalization. High titer positive antinuclear antibodies with homogeneous pattern were found. CONCLUSIONS: Our reports add to a growing body of evidence suggesting that olmesartan-associated enteropathy should be considered in the presence of villous atrophy and negative celiac serology and in the diagnostic algorithm of non-responsive celiac disease.

Small Amounts of Gluten in Subjects With Suspected Nonceliac Gluten Sensitivity: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial.

BACKGROUND & AIMS: There is debate over the existence of nonceliac gluten sensitivity (NCGS) intestinal and extraintestinal symptoms in response to ingestion of gluten-containing foods by people without celiac disease or wheat allergy. We performed a randomized, double-blind, placebo-controlled, cross-over trial to determine the effects of administration of low doses of gluten to subjects with suspected NCGS. METHODS: We enrolled 61 adults without celiac disease or a wheat allergy who believed ingestion of gluten-containing food to be the cause of their intestinal and extraintestinal symptoms. Participants were assigned randomly to groups given either 4.375 g/day gluten or rice starch (placebo) for 1 week, each via gastrosoluble capsules. After a 1-week gluten-free diet, participants crossed over to the other group. The primary outcome was the change in overall (intestinal and extraintestinal) symptoms, determined by established scoring systems, between gluten and placebo intake. A secondary outcome was the change in individual symptom scores between gluten vs placebo. RESULTS: According to the per-protocol analysis of data from the 59 patients who completed the trial, intake of gluten significantly increased overall symptoms compared with placebo (P = .034). Abdominal bloating (P = .040) and pain (P = .047), among the intestinal symptoms, and foggy mind (P = .019), depression (P = .020), and aphthous stomatitis (P = .025), among the extraintestinal symptoms, were significantly more severe when subjects received gluten than placebo. CONCLUSIONS: In a cross-over trial of subjects with suspected NCGS, the severity of overall symptoms increased significantly during 1 week of intake of small amounts of gluten, compared with placebo. Clinical trial no: ISRCTN72857280.

Absence of a role for interleukin-13 in inflammatory bowel disease.

IL-13 has been implicated in the pathogenesis of ulcerative colitis (UC), and may have a role in animal models of gut fibrosis. We studied the involvement of IL-13 in inflammation and fibrosis in UC and Crohn's disease (CD). Intestinal biopsies and anti-CD3/CD28- or anti-CD2/CD28-stimulated lamina propria mononuclear cells from UC and CD patients and control subjects were cultured, and IL-13, IL-4, IL-5, IL-17A and IFN-γ production was measured. Mucosal IL-13-producing cells were characterised by flow cytometry. Gut explants from strictured CD, non-strictured CD and healthy donors were cultured ex vivo, and secreted IL-13, IL-1ß and collagen were measured. IL-13 production by mucosal explants and activated lamina propria mononuclear cells did not differ between CD, UC and control subjects, and was at least a log lower than IFN-γ and IL-17A. IL-13-producing cells, and in particular natural killer T cells, were uniformly low in all groups. IL-4 and IL-5 were undetectable in culture supernatants. Explants of CD strictures produced low amounts of IL-13, whereas IL-1ß and collagen were elevated. We could not confirm that UC or strictured CD are associated with elevated IL-13 production. These data suggest that an anti-IL-13 Ab would not be an appropriate therapeutic strategy in inflammatory bowel disease.

A laboratory score in the diagnosis of autoimmune atrophic gastritis: a prospective study.

BACKGROUND: Several biomarkers have been proposed for the diagnosis of autoimmune atrophic gastritis (AAG), but at the present there is no appropriate testing strategy for the disease. GOALS: The aim of this study was to develop and validate a laboratory score able to address the diagnosis of AAG in a general practice setting. STUDY: We prospectively evaluated a number of serum biomarkers (vitamin B12, mean corpuscular volume, hemoglobin, gastrin, and chromogranin A levels) in a case-control population and built 2 biochemical scores, the first with all the parameters [Global Score (GS)], and the second as the best statistical combination of them [Simple Score (SS)]. In the second phase we validated the score that proved to be more efficient on a random population referred to our center (Gastroenterology Outpatient Clinic). RESULTS: Both models turned out to be reliable in detecting patients with suspected AAG, showing excellent accuracy [area under the receiver operating curve (AUC-ROC) 0.94; 95% confidence interval (CI), 0.91-0.97 for GS and AUC-ROC 0.93; 95% CI, 0.89-0.86 for SS]. The SS proved to be more convenient because of its accessibility and availability in a general setting and its low cost. The validation of the SS showed a sensitivity of 85.7% (95% CI, 57.2-98.2) and a specificity of 83.7% (95% CI, 74.2-90.89). CONCLUSIONS: Herein, we describe 2 nonexpensive and reliable score models, particularly the SS, that can be applied in daily medical practice for identifying patients potentially affected by AAG.

How I treat enteropathy-associated T-cell lymphoma.

Enteropathy-associated T-cell lymphoma (EATL) is a complication of celiac disease (CD). This tumor derives from the neoplastic transformation of aberrant intraepithelial T lymphocytes emerging in celiac patients unresponsive to a gluten-free diet. Poor adherence to a gluten-free diet, HLA-DQ2 homozygosity, and late diagnosis of CD are recognized as risk factors for malignant evolution of CD. Recurrence of diarrhea, unexplained weight loss, abdominal pain, fever, and night sweating should alert physicians to this complication. The suspicion of EATL should lead to an extensive diagnostic workup in which magnetic resonance enteroclysis, positron emission tomography scan, and histologic identification of lesions represent the best options. Treatment includes high-dose chemotherapy preceded by surgical resection and followed by autologous stem cell transplantation, although biologic therapies seem to be promising. Strict adherence to a gluten-free diet remains the only way to prevent EATL.

Autoimmune enteropathy in a 13-year-old celiac girl successfully treated with infliximab.

Autoimmune enteropathy (AIE) is a rare cause of small bowel villous atrophy, characterized by malabsorption, unresponsiveness to dietary restriction, circulating autoantibodies to enterocytes, and an overall predisposition to autoimmunity. Albeit mainly regarded as a disease of early childhood, several adult-onset AIE cases have been identified. This report describes for the first time the life-threatening clinical presentation and the management of overlapping AIE in a compliant-to-diet young celiac girl. A 13-year-old celiac girl was admitted because of vomiting, weight loss, diarrhea, hypoproteinemia, and neurological disturbances such as head tremors, vertical nystagmus, and lower limb hyperesthesia. Before this, she had always been compliant on a strict gluten-free diet and her medical history was unremarkable. The diagnosis of AIE was established on histologic findings and on the presence of antienterocyte antibodies. She was initially treated with high-dose Methylprednisolone and Azathioprine. However, only Infliximab proved itself as a highly effective tool for achieving clinical remission and restoring small bowel villous architecture.

Proteases and the gut barrier.

Serine proteases, cysteine proteases, aspartic proteases and matrix metalloproteinases play an essential role in extracellular matrix remodeling and turnover through their proteolytic action on collagens, proteoglycans, fibronectin, elastin and laminin. Proteases can also act on chemokines, receptors and anti-microbial peptides, often potentiating their activity. The intestinal mucosa is the largest interface between the external environment and the tissues of the human body and is constantly exposed to proteolytic enzymes from many sources, including bacteria in the intestinal lumen, fibroblasts and immune cells in the lamina propria and enterocytes. Controlled proteolytic activity is crucial for the maintenance of gut immune homeostasis, for normal tissue turnover and for the integrity of the gut barrier. However, in intestinal immune-mediated disorders, pro-inflammatory cytokines induce the up-regulation of proteases, which become the end-stage effectors of mucosal damage by destroying the epithelium and basement membrane integrity and degrading the extracellular matrix of the lamina propria to produce ulcers. Protease-mediated barrier disruption in turn results in increased amounts of antigen crossing into the lamina propria, driving further immune responses and sustaining the inflammatory process.

Prevalence and natural history of potential celiac disease in adult patients.

OBJECTIVE: Potential celiac disease (PCD) is a form of CD characterized by positive endomysial/tissue transglutaminase antibodies and a preserved duodenal mucosa despite a gluten-containing diet (GCD); it can evolve into flat, active CD. This evolution is, however, not certain. Our aim was to retrospectively study the prevalence and the natural history of adult patients with PCD. METHODS: The clinical notes of all 47 patients with PCD attending our clinic between September 1999 and October 2011 were retrospectively reevaluated. To study their clinical features, patients with active CD, randomly selected and matched for sex and date of birth, served as controls. Symptoms, associated diseases, familiarity, and laboratory data at diagnosis were compared. RESULTS: Prevalence of PCD among all celiac patients directly diagnosed in our center was 42/187, (1/4.4, 18.3%, 95% confidence interval (CI) 13.3-23.4%). Age at diagnosis, laboratory data, prevalence of symptoms, associated diseases, and familiarity for CD did not differ between patients with PCD and those with active CD. Some patients with PCD maintained a normal duodenal mucosa for many years and their symptoms spontaneously improved despite maintaining a GCD. CONCLUSIONS: PCD is not a rare form of CD. Having found no difference at all in age at diagnosis and clinical features between PCD and active CD could suggest that PCD is not a prodrome of CD but is a separate entity that can only subsequently evolve into active CD.

Antibodies to wheat high-molecular-weight glutenin subunits in patients with celiac disease.

BACKGROUND: Wheat gluten comprises gliadins and glutenins. The high-molecular-weight (HMW) glutenin subunits (GS)-1Dy10 are toxic for patients with celiac disease (CD). This study aimed to assess whether CD patients mount a serological response to HMW-GS-1Dy10. METHODS: Recombinant HMW-GS-1Dy10 was deamidated using human recombinant tissue transglutaminase. MALDI-TOF was performed to compare the level of deamidation of glutamine residues between material before and after treatment. Enzyme-linked immunosorbent assays were developed. Sera from patients with untreated CD and gastrointestinal disease controls were tested and receiver operator characteristics were used to calculate cutoffs. RESULTS: MALDI-TOF revealed a number of fragments matching known HMW-GS-1Dy10 sequences within both the deamidated and non-deamidated material. Evidence of deamidation of glutamine residues was found only within the human transglutaminase-treated material. Patients with untreated CD had significantly increased levels of serum antibodies to HMW-GS-1Dy10 compared to controls. Undeamidated HMW-GS-1Dy10 IgA antibodies had sensitivities and specificities of 72.5 and 78.26%, respectively. Deamidated HMW-GS-1Dy10 IgA antibodies had sensitivities and specificities of 76.8 and 65.2%. Undeamidated HMW-GS-1Dy10 IgG antibodies had sensitivities and specificities of 75.3 and 68.1%. Deamidated HMW-GS-1Dy10 IgG antibodies had sensitivities and specificities of 36.2 and 92.8%. CONCLUSION: Patients with untreated CD have raised antibody levels to HMW-GS-1Dy10, indicating the participation of these proteins in the adaptive immune response to gluten. Discrimination between CD patients and controls is not enhanced by deamidation of HMW-GS-1Dy10. Thus antibodies to these proteins are not useful markers for CD detection.