Gliadin Antibodies Research Articles

Production of omega-5 gliadin monoclonal antibodies for allergenic evaluation of WDEIA-causing wheat varieties

In allergic individuals, ingestion of wheat can lead to wheat-dependent exercise-induced anaphylaxis (WDEIA). Many studies have been conducted to find WDEIA allergen–deficient wheat, including by generating omega-5 gliadin antibodies. However, the reported antibodies have not been specific enough to detect omega-5 gliadins encoded on the 1B chromosome. In this study, we generated monoclonal antibodies against the major allergens causing WDEIA, omega-5 gliadins. Using these antibodies (mono-O5B-1C10), we assessed accumulation of omega-5 gliadins in wild-type and nullisomic-tetrasomic (NT) lines of the wheat (Triticum aestivum) varieties Chinese Spring (CS) by one- and two-dimensional gel electrophoresis, followed by Coomassie blue staining or immunoblotting with mono-O5B-1C10. We also tested mono-O5B-1C10 for major omega-5 gliadins in various wheat germplasms. Our results thus demonstrate the specificity of mono-O5B-1C10 for major omega-5 gliadins and potentially useful for identifying of omega-5 gliadin–deficient wheat varieties that should not cause WDEIA.

Celiac Disease in Syrian Children and Adolescents with Type 1 Diabetes Mellitus: A Cross-Sectional Study

Abstract Introduction Celiac disease (CD) is highly prevalent in patients with type 1 diabetes mellitus (T1DM). However, the rate of CD in Syrian children and adolescents with T1DM is unknown. We aimed to investigate the prevalence and characteristics of CD in our unprivileged rural community. Methods Children and adolescents with T1DM who were regularly followed in a private endocrine clinic in Raqqa City, Syria, were evaluated from October 2018 to November 2021. Screening for CD was performed using either anti-tissue transglutaminase antibodies, antideaminated gliadin antibodies, or endomysial antibodies. Patients with positive results were referred for duodenal biopsy using Marsh classification whenever possible. The prevalence of CD was calculated for both seropositive and biopsy-proven cases. Results Ninety-four patients with T1DM, 51 (54.3%) females, were included. The mean age was 11.6 years, and mean hemoglobin A1c (HbA1C) was 9.2%. All patients were screened for CD. Fourteen patients (14.9%) were positive, and seven (7.4%) performed a duodenal biopsy that proved positive for CD in all cases. CD seropositivity was more common in female than male patients (21.6 vs. 7%, respectively, p-value <0.05). Patients with seropositivity for CD had lower hemoglobin levels compared to seronegative patients, with a mean difference of 0.87 (95% confidence interval: 0.2–1.5; p-value <0.05). There was a statistically significant correlation between hypothyroidism and celiac seropositivity (p-value <0.05). There were no differences in age, weight, height, HbA1C, puberty status, or duration of diabetes between patients with and without CD. No correlation was identified between the incidence of hypoglycemia or diabetic ketoacidosis and the presence of CD. Conclusion In our community, we revealed a high prevalence of CD in Syrian children and adolescents with T1DM. Our results are alarming and point to the need for establishing a national CD registry to prompt physicians for proper screening and early management in high-risk populations.

The role of serology in the diagnosis of coeliac disease.

Serology has significantly revolutionized the knowledge of celiac disease (CD), leading to the identification of unsuspected patients in at-risk CD groups, thereby increasing the number of CD diagnoses compared to the pre-screening era. Several markers for CD with a progressive diagnostic accuracy have been identified over the years, but only three of them, i.e. anti-tissue transglutaminase (anti-tTG), anti-endomysial (EmA) and anti-deamidated gliadin antibodies (DGP) are currently assessed in the daily clinical practice. A thorough review of the literature identified 44 original studies published between 1998 to 2022 for a total of 5098 pediatric and adult CD patients (without selective IgA deficiency) and 11930 disease controls. The results highlighted that anti-tTG IgA exhibited a higher sensitivity for CD (93.4%) than EmA IgA (92.8%), DGP IgG (81.8%) and DGP IgA (83.8%). The specificity of EmA IgA (99%) resulted to be higher than those of anti-tTG IgA (95.8%), DGP IgG (96.4%) and DGP IgA (92.1%). In patients with selective IgA deficiency, a condition closely related to CD, serological screening should include one of the three antibodies of IgG class, since anti-tTG, DGP and EmA have a very similar diagnostic accuracy in this clinical setting. According to age, there are two main diagnostic strategies for CD detection. In children, the revised ESPGHAN 2020 guidelines established that CD could be diagnosed in both symptomatic and asymptomatic children by high anti-tTG IgA titers (>10 times the cut-off) and EmA positivity with no need to obtain duodenal biopsy and HLA typing. In adult patients, although high tTG IgA titers (confirmed by EmA IgA positivity) correlate with villous atrophy, an intestinal biopsy is still considered mandatory for confirming CD diagnosis. Currently, a case finding approach in at-risk groups is preferred to mass screening for CD detection.

Point-of-Care Screening for Coeliac Disease in Schoolchildren Reveals Higher Disease Prevalence in Croatia

Coeliac disease (CD) is an immune-mediated inflammatory disease triggered by dietary gluten and related proteins in genetically predisposed individuals. Point-of-care (POC) methods are non-invasive and easily performed tests, which could help to reduce the diagnostic delay of CD. The aim of our study was to determine the prevalence of CD using rapid POC test in first-grade schoolchildren in Zagreb, Croatia. A rapid qualitative immunoassay POC test designed for detection of immunoglobulin (Ig) A and IgG deamidated gliadin antibodies (DGP), as well as total IgA (to identify IgA deficient patients) in whole blood, was used to test healthy children on gluten containing diet. Out of 1404 tested children (51% female), 85 (6.05%) had a positive rapid POC test result and were referred to paediatric gastroenterologist. Finally, 7 children were diagnosed with CD (0.5%). There was no significant difference in children with CD and children with positive POC but negative serology in sex, BMI, or symptoms. However, children diagnosed with CD complained of abdominal pain significantly more often. The prevalence of CD in first-grade schoolchildren was 1:200 (0.5%), higher than in previous studies performed in Croatia. The results imply the possible benefit of IgA and IgG DGP-based POC tests in population screening.

Who to screen and how to screen for celiac disease

Celiac disease (CeD) is a chronic gluten-induced enteropathy with plethoric manifestations. The typical manifestations of CeD such as chronic diarrhea and malabsorption are widely recognized, however, many patients have atypical manifestations like iron deficiency anemia, idiopathic short stature, hypertransaminesemia or infertility, etc. These patients often present to the primary care physicians and/or non-gastrointestinal specialties. However, due to a lack of awareness among the healthcare professionals about the various atypical manifestations, many patients are not screened for CeD. In this review, we have summarized the available literature about the prevalence of CeD in various gastrointestinal (chronic diarrhea) and non-gastrointestinal conditions (iron deficiency anemia, short stature, cryptogenic hypertransaminesemia, cryptogenic cirrhosis or idiopathic ataxia etc.) where the diagnosis of CeD should be con-sidered. In addition, we also discuss special scenarios where screening for CeD should be considered even in absence of symptoms such as patients with type 1 diabetes, Down’s syndrome, and first-degree relatives of patients with CeD. Further, we discuss the diagnostic performance and limitations of various screening tests for CeD such as IgA anti-tissue transglutaminase antibodies, anti-endomysial antibodies and anti-deamidated gliadin antibodies. Based on the current recommendations, we propose a diagnostic algorithm for patients with suspected CeD.

Gene variants of the SLC2A5 gene encoding GLUT5, the major fructose transporter, do not contribute to clinical presentation of acquired fructose malabsorption

BackgroundWhile role of ALDOB-related gene variants for hereditary fructose intolerance is well established, contribution of gene variants for acquired fructose malabsorption (e.g. SLC2A5, GLUT5) is not well understood.MethodsPatients referred to fructose breath test were further selected to identify those having acquired fructose malabsorption. Molecular analysis of genomic DNA included (I) exclusion of 3 main ALDOB gene variants causing hereditary fructose intolerance and (II) sequencing analysis of SLC2A5 gene comprising complete coding region, at least 20 bp of adjacent intronic regions and 700 bp of proximal promoter.ResultsAmong 494 patients, 35 individuals with acquired fructose malabsorption were identified based on pathological fructose-breath test and normal lactose-breath test. Thirty four of them (97%) had negative tissue anti-transglutaminase and/or deamidated gliadin antibodies in their medical records. Molecular analysis of SLC2A5 gene of all 35 subjects identified 5 frequent and 5 singular gene variants mostly in noncoding regions (promoter and intron). Allele frequencies of gene variants were similar to those reported in public databases strongly implying that none of them was associated with acquired fructose malabsorption.ConclusionsGene variants of coding exons, adjacent intronic regions and proximal promoter region of SLC2A5 gene are unlikely to contribute to genetic predisposition of acquired fructose malabsorption.

Clinical Relevance of Anti-Gliadin Seropositivity in the Ageing Population: A Long-term Follow-up Study.

To explore if anti-gliadin antibody (AGA) positivity is associated with overall mortality or morbidity and especially with the development of coeliac disease during long-term gluten exposure. The study population comprised 130 persistently AGA-positive but transglutaminase-2 (anti- TG2) -negative and 52 persistently AGA- and anti-TG2 -negative subjects aged 64-88 years. HLA-typing for DQ2 and DQ8 (coeliac-type HLA) was performed on the AGA-positives. The medical records of the study population were reviewed to compare mortality and morbidity during a long-term follow-up of 12-13 years since the initial antibody analysis. Mortality or cumulative prevalence of gastroenterological, autoimmune, psychiatric, cardiovascular or any malignant diseases did not differ statistically between the AGA-positives and the AGA-negatives. Neurological diseases were more common in the AGA-negative group (p=0.017), but there was no statistical difference between the prevalence of any particular neurological diseases. Coeliac-type HLA in AGA-positive subjects did not influence mortality or morbidity. However, during the last six to seven years the incidence of immunological diseases was more common in the AGA-positive subjects without coeliac-type HLA than in those with coeliac-type HLA, or in the AGA-negative group (p=0.020). None of the persistently AGA-positive subjects developed clinically diagnosed coeliac disease. Gliadin antibody positivity without coeliac disease does not predict mortality or morbidity in the ageing population continuing to consume gluten for over ten years.

Specific Avenin Cross-Reactivity with G12 Antibody in a Wide Range of Current Oat Cultivars.

Current clinical studies confirm that the consumption of oats for people suffering from celiac disease is safe. Some studies have confirmed different levels of immunoreactive gluten epitopes of oats in different cultivars, while others explain these differences due to contamination with gluten-rich species or as random cross-reactivity ELISA of homologous oat epitopes with anti-wheat gliadin antibodies. The aim of our two-year study was therefore to map cross-reactive oat epitopes in a set of 132 oat cultivars using a G12-based ELISA kit. The results were focused on the varietal and annual level of cross-reactivity (interference) of avenin epitopes with the G12 antibody on the identification of potential cultivars with significantly different interferences and assessing the degree of risk of possible false-contamination with external gluten. Although repeated evaluations confirmed high year-to-year variability (RSD ≥ 30%) in approximately 2/3 of the cultivars, the content of interfering avenin epitopes with G12 did not exceed the considered safe limit (20 mg·kg−1) for celiacs. At the same time, not only annual but, above all, significant cultivar dependences in the interference of avenins to the G12 antibody were demonstrated. Genetic dependence was further confirmed in connection with the proven avenin polymorphism as well as immunoblotting with the identification of interfering peptides with the G12 antibody in the 25 and 30 kDa regions. It was the occurrence of two bands around 30 kDa that predominantly occurred in oat cultivars with a relatively higher content of cross-reactive avenins (12–16 mg·kg−1). Due to the fact that the contents of interfering avenins ranged in several cultivars even over 16 mg·kg−1, the choice of a suitable oat cultivar may be crucial for gluten-free food producers, as it reduces the risk of a possible false-response of the commercial ELISA kits when checking the real-gluten contamination.

Prevalence of coeliac disease in children and adolescents with type 1 diabetes mellitus in a tertiary hospital in South Africa

Background. International literature has shown the prevalence of coeliac disease (CD) in children and adolescents with diabetes to range from 1 - 10%. Prevalence rates in African countries are limited or unknown. Objective. The objective was to describe the prevalence of CD in all children and adolescents with type 1 diabetes mellitus presenting to the paediatric and adult diabetic clinic at Steve Biko Academic Hospital, Pretoria, South Africa. Method. A retrospective review of the files of all children and adolescents in the paediatric and adult diabetic clinic with type 1 diabetes mellitus between August 2016 and June 2019 was conducted. Children requiring screening and/or intestinal biopsies were also prospectively included during this period. The setting of this study was Steve Biko Academic Hospital, a tertiary referral centre, in Pretoria, South Africa. Coeliac screening included anti-deaminated gliadin antibodies and anti-tissue transglutaminase antibodies (both IgA and IgG). All biopsies were obtained by a paediatric gastroenterologist or an experienced paediatric surgeon. Results. A total of 184 files were screened; 132 met inclusion criteria but only 108 patients in total had coeliac screening. Positive antibody screening for CD was found in 11 out of 108 patients (10.2%). Nine of the 11 serology-positive patients had biopsies performed. Out of the nine biopsies, two (22.2%) were positive for CD based on the Marsh-Oberhuber classification. Conclusion. This study found a prevalence of serology-positive CD in our local population of South African children with type 1 diabetes mellitus of 10.2%, while the prevalence of biopsy-confirmed CD was found to be 1.9%.

Adrenal Insufficiency Presenting as Hypoglycemia & Hyponatremia in a Patient With Liver Cirrhosis; Hepatoadrenal Syndrome

Hepatoadrenal syndrome is described as a progressive impairment in the adrenocortical reserve in advanced liver disease resulting in relative adrenal insufficiency (AI). This can present as critical hypoglycemia and hyponatremia as in the case described.54 year old male with past medical history of hypothyroidism, pericardial effusion, liver cirrhosis and prior alcohol use disorder presented to the hospital with altered mental status. He felt lethargic and complained of recurrent diarrhea for a month. His blood sugar was 30 mg/dl (n=70–140 mg/dl) for which he received dextrose and his mentation improved. He was hypothermic with stable vitals otherwise. There was no skin hyperpigmentation. Labs demonstrated sodium of 123 mmol/L (n=136–145 mmol/L) and pancytopenia. TSH, ammonia, renal and hepatic functions were within normal limits except mildly elevated AST and total bilirubin. Total protein, albumin, HDL, Insulin and cortisol levels were low. Hepatitis panel was negative. CT Chest, abdomen and pelvis revealed massive abdominopelvic ascites, hepatic cirrhosis and splenomegaly. Adrenal glands appeared normal. Urine studies were consistent with salt-wasting nephropathy. Patient was started on intravenous fluids as well as dexamethasone. Diagnostic and therapeutic paracentesis was performed. Cosyntropin stimulation test revealed a baseline AM cortisol of 2.0 ug/dl (n=4.3–22.4 ug/dl), 30 min value of 4.0 ug/dl and 60 min value of 5.8 ug/dl (n=18-22ug/dl). Delta cortisol level was also low. Treatment with hydrocortisone was initiated until ACTH levels became available. To rule out sarcoidosis, ACE levels were obtained, which were normal. Dihydroxy 1,25 Vitamin D levels were low. ACTH returned as 21.7 pg/ml (n=7.2–63.3 pg/ml). 21 hydroxylase antibody was negative. MRI brain with IV contrast demonstrated no pituitary mass or abnormality. Blood cultures, body fluid cultures, AMA and ASMA were negative. Anti- tTG and Anti Gliadin antibodies were positive confirming celiac disease. Patient was started on gluten free diet which resolved his diarrhea. He responded well to steroids however, he remained intermittently confused which was thought to be related to hypoglycemic brain injury. Patient was converted to hydrocortisone PO 20 mg in AM and 10 mg in PM and advised to follow up outpatient with endocrinologist and gastroenterologist.Hepatoadrenal syndrome is an important differential to consider in patients with liver disease presenting with hypoglycemia and hyponatremia. It is a potentially life-threatening condition requiring immediate treatment and appropriate work up. The condition improves with corticosteroid replacement therapy.Reference: Anastasiadis SN, Giouleme OI, Germanidis GS, Vasiliadis TG. Relative adrenal insufficiency in cirrhotic patients. Clin Med Insights Gastroenterol. 2015;8:13–17. Published 2015 Mar 2. doi:10.4137/CGast.S18127

Influence of Age and Type 1 Diabetes Mellitus on Serological Test for Celiac Disease in Children.

PurposeSerological tests of tissue transglutaminase (TTG) and deamidated gliadin (DGP) antibodies for celiac disease diagnosis show conflicting correlation with histology in young children and in type 1 diabetes mellitus (T1DM). Tests' ability to predict histology and cutoff values based on age and T1DM was evaluated.MethodsA retrospective study of children who had celiac serological tests between 6/1/2002 and 12/31/2014 at a pediatric hospital.ResultsTTG IgA displayed similar results in predicting histology between <4.0 and ≥4.0 years age groups with sensitivity 98% and 93%, and specificity 88% and 86%, respectively. In children <4.0 years old, sensitivity for DGP antibodies was 100% and specificity 94%; in ≥4.0 years age groups, sensitivity was 60%, 88% for DGP IgA and IgG and specificity 95%, 96%, respectively. TTG IgA had low specificity in patients with T1DM compared with non-T1DM, 42% vs. 91%. Positive TTG IgA with normal histology was associated with higher T1DM prevalence at 36% compared with negative tests at 4%. Finally, the TTG IgA cutoff value was higher in T1DM at 36 vs. 16.3 units in non-T1DM. DGP IgG cutoff showed similar values between age groups; TTG IgA and DGP IgA cutoffs were lower in <4.0 years at 8.3 and 11.9 units than ≥4.0 years at 23.4 and 19.9, respectively.ConclusionTTG IgA is sufficient for the <4.0 years age group and DGP antibodies had no advantage over TTG IgA in older children. The cutoff value to determine a positive TTG IgA should be higher for children with T1DM.

Functionalized TiO2 Nanotube Platform for Gliadin Electroanalysis

The present paper presents a gliadin detection method. This method is based on a modified Ti electrode. Modification was performed by a simple and cheap anodization. Then, a layer of graphene oxide was added, and gliadin antibody was fixed on the electrode surface. Using this complex system, electrochemical impedance spectroscopy was used for gliadin detection. Solutions with known gliadin (a fraction from gluten) content were used for analysis. Impedance measured at a certain frequency and coating resistance were analyzed. Better results (good linearity and lower detection limit) were obtained by plotting impedance at a certain frequency versus gliadin concentration. Coating resistance was proved to be in linear dependency with gliadin concentration only at lower concentrations. This system based on titanium nanostructured electrode has the potential to be used for gluten contamination detection from foods.

Deamidated Gliadin Antibodies: Do They Add to Tissue Transglutaminase-IgA Assay in Screening for Celiac Disease?

Use of deamidated gliadin peptide (DGP) test kits as adjunctive to tissue-transglutaminase-IgA (TTG-IgA) for the diagnosis of celiac disease (CD) has been a controversial issue. The objectives of our study were to evaluate the diagnostic performance of DGP antibodies compared with TTG-IgA and to evaluate the correlation between DGP-antibody titers and degree of enteropathy. We included children who underwent endoscopy and biopsies because of positivity of any of the serology tests in the "celiac profile" (TTG-IgA, DGP-IgA, and DGP-IgG) from 2012 to 2019. We divided children into clinically suspected cases of CD (group 1) and asymptomatic cases screened as they were from a high-risk group (group 2). Group 1 constituted 52 children and group 2 included 81 children (76 type-1 diabetes [T1D]). The sensitivity and positive-predictive value (PPV) of DGP-IgG in group 1 (90%, 98%) and group 2 (91%, 85.5%) were comparable with TTG-IgA (98%, 92% in group 1; 100%, 80% in group 2). By adding DGP-IgG to TTG-IgA, the performance of TTG-IgA has improved marginally in group 1 (sensitivity 100%, PPV 92.3%). All cases with DGP-IgG titer 2 times ULN in group 1, and >4 times ULN in group 2 had villous atrophy. All T1D patients with TTG IgA >10 times ULN had villous atrophy. DGP-IgG assay did not add to the performance of TTG-IgA. DGP-IgG titer correlated with enteropathy. The diagnosis of CD can be made in asymptomatic T1D child with TTG-IgA titer >10 times ULN and positive endomyseal antibodies.

Development of a nano biosensor for anti-gliadin detection for Celiac disease based on suspension microarrays

Celiac disease is an autoimmune disorder represented by the ingestion of the gluten protein usually found in wheat, barley and rye. To date, ELISA has been the most accurate method for determining the presence of anti-gliadin, which is cumbersome, expensive (compared to a suspension microarray technique), and requires extensive sample preparation. In this study, in order to establish a more accurate assay to identify gliadin at lower concentrations, optical nano biosensors using an indirect immunoassay method for gliadin detection was designed and fabricated. For this, polycaprolactone (PCL) nano- to micro-beads were fabricated as a platform for the gliadin antigen which were optimized and nano functionalized with amine groups for such purposes. The gliadin antibody, which is selective to gliadin, was then added to the beads. Static light scattering tests were conducted to determine PCL particle size distribution and sizes were found from 0.1 to 30 μm, which is suitable for flowcytometry detection devices. Anti-gliadin detection was performed using an anti IgG mouse antibody conjugated with FITC in a flow cytometry device to detect the smallest particle. Fluorescence intensity was investigated at different concentrations of anti-gliadin and a standard curve used to determine gluten concentration based on fluorescence intensity. Results showed that the fluorescence intensity increased with greater concentrations of anti-gliadin providing a very effective method of detection due to selectivity at a 5 ppm detection limit. This represents a new highly sensitive and fast method for anti-gliadin detection. Further, the disuse of a cross linker and the use of a dedicated antibody at a very low level (1 μl) made this new method very economical to identify anti-gliadin concentrations at the nano level. In summary, this study provides a new, more accurate and sensitive, as well as less expensive system to detect anti-gliadin for the improved diagnosis of celiac disease.

Current Evidence on the Efficacy of Gluten-Free Diets in Multiple Sclerosis, Psoriasis, Type 1 Diabetes and Autoimmune Thyroid Diseases

In this review, we summarize the clinical data addressing a potential role for gluten in multiple sclerosis (MS), psoriasis, type 1 diabetes (T1D) and autoimmune thyroid diseases (ATDs). Furthermore, data on the prevalence of celiac disease (CD) and gluten-related antibodies in the above patient groups are presented. Adequately powered and properly controlled intervention trials investigating the effects of a gluten-free diet (GFD) in non-celiac patients with MS, psoriasis, T1D or ATDs are lacking. Only one clinical trial has studied the effects of a GFD among patients with MS. The trial found significant results, but it is subject to major methodological limitations. A few publications have found beneficial effects of a GFD in a subgroup of patients with psoriasis that were seropositive for anti-gliadin or deamidated gliadin antibodies, but no effects were seen among seronegative patients. Studies on the role of gluten in T1D are contradictive, however, it seems likely that a GFD may contribute to normalizing metabolic control without affecting levels of islet autoantibodies. Lastly, the effects of a GFD in non-celiac patients with ATDs have not been studied yet, but some publications report that thyroid-related antibodies respond to a GFD in patients with concomitant CD and ATDs. Overall, there is currently not enough evidence to recommend a GFD to non-celiac patients with MS, psoriasis, ATDs or T1D.

Application of corn zein as an anchoring molecule in a carbon nanotube enhanced electrochemical sensor for the detection of gliadin

This research focused on the fabrication of an electrochemical sensor capable of detecting the protein ‘gliadin’, which is responsible for serious autoimmune disorder causing chronic diarrhea, fatigue, weight loss and anemia in people having celiac disease. The fabrication process involves the replacement of toxic synthetic chemicals that are used for anchoring of the capture antibody in the working electrode, by the natural polymer zein coupled with several nanoparticles including, carbon nanotubes, graphene oxide and Laponite®. Novel biodegradable coatings made from zein nanocomposites: zein-graphene oxide (Z-GO), zein-Laponite® (Z-LAP) and zein-multiwalled carbon nanotubes (Z-CNT) using drop casting nanocomposite technique were tested for fabricating the electrochemical sensors using cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS). Pristine zein coated electrode did not generate any oxidation/reduction peaks in the cyclic voltammograms and showed high degree of impedance in the EIS curves. While addition of the three nanoparticles (CNT, LAP, GO) considerably improved the electrical signal, Z-CNT gave the highest and strongest signals compared to other nanomaterials. The active tip of the electrochemical sensor was functionalized through a sequence of layer by layer deposition of Z-CNT nanocomposite, and other linker molecules, where Z-CNT acts as a natural linker molecule with large number of functional groups that offers immobilization of capture antibody and target and ensures high performance. Both CV curves and SWV curves indicated successful sequential immobilization of gliadin antibody onto the Z-CNT coated electrode. The Z-CNT biosensor was successfully able to give CV signals for gliadin allergens for as low as 0.5 ppm, and was highly selective for gliadin, when tested against other food toxins like acrylamide and formamide, and the Z-CNT nanocomposite remained stable over a 30-day period.

Gliadin Nanoparticles Induce Immune Tolerance to Gliadin in Mouse Models of Celiac Disease

Celiac disease could be treated, and potentially cured, by restoring T-cell tolerance to gliadin. We investigated the safety and efficacy of negatively charged 500-nm poly(lactide-co-glycolide) nanoparticles encapsulating gliadin protein (TIMP-GLIA) in 3 mouse models of celiac disease. Uptake of these nanoparticles by antigen-presenting cells was shown to induce immune tolerance in other animal models of autoimmune disease. We performed studies with C57BL/6; RAG1-/- (C57BL/6); and HLA-DQ8, huCD4 transgenic Ab0 NOD mice. Mice were given 1 or 2 tail-vein injections of TIMP-GLIA or control nanoparticles. Some mice were given intradermal injections of gliadin in complete Freund's adjuvant (immunization) or of soluble gliadin or ovalbumin (ear challenge). RAG-/- mice were given intraperitoneal injections of CD4+CD62L-CD44hi T cells from gliadin-immunized C57BL/6 mice and were fed with an AIN-76A-based diet containing wheat gluten (oral challenge) or without gluten. Spleen or lymph node cells were analyzed in proliferation and cytokine secretion assays or by flow cytometry, RNA sequencing, or real-time quantitative polymerase chain reaction. Serum samples were analyzed by gliadin antibody enzyme-linked immunosorbent assay, and intestinal tissues were analyzed by histology. Human peripheral blood mononuclear cells, or immature dendritic cells derived from human peripheral blood mononuclear cells, were cultured in medium containing TIMP-GLIA, anti-CD3 antibody, or lipopolysaccharide (controls) and analyzed in proliferation and cytokine secretion assays or by flow cytometry. Whole blood or plasma from healthy volunteers was incubated with TIMP-GLIA, and hemolysis, platelet activation and aggregation, and complement activation or coagulation were analyzed. TIMP-GLIA did not increase markers of maturation on cultured human dendritic cells or induce activation of T cells from patients with active or treated celiac disease. In the delayed-type hypersensitivity (model 1), the HLA-DQ8 transgenic (model 2), and the gliadin memory T-cell enteropathy (model 3) models of celiac disease, intravenous injections of TIMP-GLIA significantly decreased gliadin-specific T-cell proliferation (in models 1 and 2), inflammatory cytokine secretion (in models 1, 2, and 3), circulating gliadin-specific IgG/IgG2c (in models 1 and 2), ear swelling (in model 1), gluten-dependent enteropathy (in model 3), and body weight loss (in model 3). In model 1, the effects were shown to be dose dependent. Splenocytes from HLA-DQ8 transgenic mice given TIMP-GLIA nanoparticles, but not control nanoparticles, had increased levels of FOXP3 and gene expression signatures associated with tolerance induction. In mice with gliadin sensitivity, injection of TIMP-GLIA nanoparticles induced unresponsiveness to gliadin and reduced markers of inflammation and enteropathy. This strategy might be developed for the treatment of celiac disease.

New celiac disease biomarkers.

Advances in the knowledge regarding celiac disease have enabled the development of diagnostic markers, such as anti-tissue transglutaminase and anti-deaminated gliadin antibodies. The wide availability of these antibodies, genetic studies of HLA-DQ and duodenal biopsies constitute the pillars necessary for a definitive diagnosis. However, difficulties sometimes arise in both the diagnosis and follow-up of celiac patients, which cannot be resolved using these tools. This article reviews the scientific evidence and possible clinical utility of different biomarkers. This review is structured according to biomarkers that have been evaluated pathophysiologically in relation to intestinal damage or immune response and their potential clinical utility in the diagnosis and follow-up of celiac disease patients.

Mixing dynamics and molecular interactions of HMW glutenins, LMW glutenins, and gliadins analyzed by fluorescent co-localization and protein network quantification

Gluten proteins and their impact affecting the texture and rheology of wheat-based food products is well-known. We are now using newly developed antibodies for LMW and HMW glutenins along with gliadin antibodies, all of them conjugated with Quantum Dots to visualize these gluten subunits in wheat dough during dough mixing. We are also using Confocal Laser Scanning Microscopy and image analysis software from to obtain quantitative analysis regarding the degree of co-localization of the different gluten subunits in the same dough area and the quantification of the gluten network branches. The co-localization coefficient is shown as a promising technique to evaluate the interaction between different components in dough samples. We are linking the qualitative observations and quantitative data of gliadins, LMW glutenins, and HMW glutenins to dough physical characteristics at different stages of mixing in a Brabender farinograph. During dough mixing the three gluten subunits associate together to form a strong gluten network however, with continuous mixing, LMW glutenins dissociate from the network first, followed by a later dissociation of the HMW glutenins. Visualizing the distribution of the gluten subunits during mixing is helping us advance our understanding of the mechanism of dough development.

Gut permeability and mimicry of the Glutamate Ionotropic Receptor NMDA type Subunit Associated with protein 1 (GRINA) as potential mechanisms related to a subgroup of people with schizophrenia with elevated antigliadin antibodies (AGA IgG)

About one third of people with schizophrenia have elevated IgG antibodies to gliadin (AGA IgG) and increased inflammation. Understanding the mechanism by which this immune response occurs is critical to the development of personalized treatments. We examined gut permeability and mimicry to the glutamate receptor as possible mechanisms related to high gliadin antibodies (AGA IgG) seen in some people with schizophrenia. The Glutamate Ionotropic Receptor NMDA type Subunit Associated with protein 1 (GRINA) has a similar protein structure to gliadin representing a potential target for cross reactivity or mimicry. In a population of schizophrenia subjects (N = 160) and healthy controls (N = 80) we analyzed serum samples for both GRINA and Anti-Saccharomyces Cerevisiae antibodies (ASCA), related to gut permeability. Schizophrenia patients compared to controls had a higher prevalence of positivity to ASCA IgA (p = 0.004) and IgG (p < 0.001). Multinomial logistic regression showed an association between AGA IgG and ASCA IgG in schizophrenia (p = 0.05 for the estimated regression coefficient) but not in healthy controls (p = 0.13). GRINA IgG was higher in schizophrenia patients than in healthy controls (0.43 ± 0.30 vs. 0.22 ± 0.24, p < 0.001). Logistic regressions showed an association between AGA IgG and GRINA IgG in schizophrenia (p = 0.016 for the estimated regression coefficient) but not for the controls (p = 0.471). Thus, we propose that mimicry through the presence of cross-reactivity between gliadin and GRINA might disrupt the functions of the glutamate system and relate to illness pathophysiology in those with schizophrenia and elevated AGA IgG.