Anti-deamidated Gliadin Peptide Research Articles

Parathyroid Hormone and Osteocalcin as Criteria for Osteoporosis in Patients with Celiac Disease

Background: Osteoporosis is a disease that affects the entire skeletal system. It is characterized by the deterioration of the fine structural structure of the bone and the decline in bone mass, which ultimately leads to an increase in the bone's susceptibility to fracture. Celiac disease, often known as wheat allergy, is a single condition with numerous names. Celiac disease is a chronic autoimmune disorder that mostly affects the small intestine. It occurs when patients develop an intolerance to gluten, a protein found in foods including wheat, rye, and barley. Aim of the study: The objective of our study is to track the levels of osteocalcin and parathyroid hormone in the blood serum of patients diagnosed with celiac disease in Wasit Governorate, Iraq. We will be using Human Anti-Deamidated Gliadin Peptide IgG and IgA to diagnose celiac disease and evaluate the progress of bone health. Materials and methods: This study examined a total of 80 samples, consisting of 50 samples from individuals with celiac disease. The sample group included 19 males and 31 women. There are 30 control samples, with an equal number of samples for each sexes. Utilized an Enzyme-linked immunosorbent assay (ELISA) kit to quantify the levels of osteocalcin, parathyroid hormone, and Human Anti-Deamidated Gliadin Peptide IgG and IgA. Results: The study revealed that individuals with celiac disease had significantly higher levels of osteocalcin, parathyroid hormone, and Human Anti-Deamidated Gliadin Peptide IgG and IgA compared to the control group, with a statistical significance of p≤(0.05). Conclusion: The examined parameters serve as indicators of the development of health risks to the body and bone health in individuals with celiac disease.

Autoantibodies related to ataxia and other central nervous system manifestations of gluten enteropathy

Gluten ataxia and other central nervous system disorders could be linked to gluten enteropathy and related autoantibodies. In this narrative review, we focus on the various neuro-logical manifestations in patients with gluten sensitivity/celiac disease, immunological and autoimmune mechanisms of ataxia in connection to gluten sensitivity and the autoantibodies that could be used as a biomarker for diagnosing and following. We focused on the anti-gliadin antibodies, antibodies to different isoforms of tissue transglutaminase (TG) (anti-TG2, 3, and 6 antibodies), anti-glycine receptor antibodies, anti-glutamine acid decarboxylase antibodies, anti-deamidated gliadin peptides antibodies, etc. Most studies found a higher prevalence of these antibodies in patients with gluten sensitivity and neurological dysfunction, presented as different neurological disorders. We also discuss the role of a gluten-free diet on the clinical improvement of patients and also on imaging of these disorders.

A69 EXPANDED ROLE OF THE DIETITIAN IN THE CLINICAL MANAGEMENT OF PATIENTS WITH CELIAC DISEASE

Abstract Background The only available treatment for Celiac Disease (CeD) is adhering to a strict gluten-free diet (GFD). However, a GFD has been associated with multiple nutrient imbalance and deficiencies, which are often under-recognized and remain untreated. Aims To identify the reasons for referral to a registered dietitian (RD) and RD-recommended dietary interventions for patients with CeD attending a specialised Adult Celiac Disease Clinic. Methods We conducted a retrospective chart review using nutrition assessment forms completed by the RD between November 2021 and May 2022. CeD diagnosis was performed through specific serology (anti-tissue transglutaminase IgA and anti-deamidated gliadin peptide IgG) and confirmed by duodenal biopsies demonstrating villous atrophy. We collected data on demographics, diagnosis date, nutritional status (BMI), micronutrients measured in serum, gastrointestinal (GI) symptoms, reason for consult, and the recommendations made by the RD. Data was collected in RedCap (v. 11.1, 2021, US) and expressed as both a proportion and Median (IQR). Results A total of 136 visits from 102 patients were included in the analysis. Of them, 77 were female (75.5%) with a mean age of 40.3 yrs (+/- 16.0). The median year of CeD diagnosis was 4 (IQR= 6) from 2002-2022. Patients reported various symptoms including bloating (50.9%), abdominal pain (34.3%), and constipation (23.5%). 56% of patients were overweight or obese (BMI ampersand:003E25), and 4.9% were undernourished (BMIampersand:003C18). The most common nutrient deficiencies were ferritin below 30 ng/mL (58.8%), zinc below 9.4 µmol/L (23.5%), and suboptimal levels of vitamin D (38.2%). The most common reasons for referral to the RD were to assess GFD adherence (44.1%), dietary management of GI symptoms (30.4%) and nutritional optimization (24.5%). We identified 18 different interventions recommended by the RD, the most common being how to prevent gluten cross-contamination (58.8%), tips for dining out (43.1%), GF diet education (32.4%), and increasing fibre intake (30.4%). The most common reasons for follow up visits (n=34) included dietary management of GI symptoms (60.9%) and GFD adherence (43.5%). Conclusions Patients with CeD face multiple nutritional challenges associated with following a GFD, and a number of GI symptoms. Although the GFD is the only available treatment, this review identifies the need for multiple individualized dietary interventions, which require and encourage the inclusion of a specialized RD to ensure personalized, effective care and support in the management of CeD. Funding Agencies None

A Case of Celiac Disease with Pericardial Effusion

Celiac disease is a unique enteropathic immune disorder and is now considered a distinct disease entity with protein manifestation and worldwide distribution. The deposition of immune complexes in the small intestine could be a possible reason for the extraintestinal autoimmune manifestations of Celiac disease. Pericardial effusion, though rare in adults, is likely a result of these autoimmune disorders related to Celiac disease. In present study case report, the authors present the case of a 67-year-old female patient with generalised oedema, anasarca, and pitting oedema in the lower extremities. Due to multiple episodes of vomiting, upper gastrointestinal endoscopy was performed, which revealed atrophic duodenal mucosa, and duodenal biopsies were taken from the second part of the duodenum (D2 biopsies). The possibility of Celiac disease was considered, and anti-deamidated gliadin peptide, Immunoglobulin A (IgA), and Immunoglobulin G (IgG) antibodies were sent. Celiac disease was diagnosed based on elevated serum levels of anti-deamidated gliadin peptide, IgA, and IgG antibodies, as well as histologic findings in the small bowel (duodenal biopsies D2). During the thorough evaluation, pericardial effusion was incidentally detected. Celiac disease is an autoimmune disorder in which exposure to gluten triggers inflammation in genetically predisposed individuals. The illness is estimated to have a prevalence of 2%, and most affected people remain undiagnosed. Pericardial effusion is a possible manifestation of Celiac disease, but there is currently no evidence that the disease directly causes the effusion.

A Case of Celiac Disease with Pericardial Effusion

Celiac disease is a unique enteropathic immune disorder and is now considered a distinct disease entity with protein manifestation and worldwide distribution. The deposition of immune complexes in the small intestine could be a possible reason for the extraintestinal autoimmune manifestations of Celiac disease. Pericardial effusion, though rare in adults, is likely a result of these autoimmune disorders related to Celiac disease. In present study case report, the authors present the case of a 67-year-old female patient with generalised oedema, anasarca, and pitting oedema in the lower extremities. Due to multiple episodes of vomiting, upper gastrointestinal endoscopy was performed, which revealed atrophic duodenal mucosa, and duodenal biopsies were taken from the second part of the duodenum (D2 biopsies). The possibility of Celiac disease was considered, and anti-deamidated gliadin peptide, Immunoglobulin A (IgA), and Immunoglobulin G (IgG) antibodies were sent. Celiac disease was diagnosed based on elevated serum levels of anti-deamidated gliadin peptide, IgA, and IgG antibodies, as well as histologic findings in the small bowel (duodenal biopsies D2). During the thorough evaluation, pericardial effusion was incidentally detected. Celiac disease is an autoimmune disorder in which exposure to gluten triggers inflammation in genetically predisposed individuals. The illness is estimated to have a prevalence of 2%, and most affected people remain undiagnosed. Pericardial effusion is a possible manifestation of Celiac disease, but there is currently no evidence that the disease directly causes the effusion.

Gluten Enteropathy in Adult Iraqi Patients: Immunological and Histopathological Assessment (A Cross-Sectional Study)

Background: Gluten-enteropathy or Celiac disease (CD) is a well-known autoimmune gastroenteropathy. The disease incidence is globally like an iceberg with many cases are believed to be undiscovered in the community. Many researches are continuously done to detect the pathogenesis of the disease. Soluble Interleukin-2 receptor (sIL-2R) is well a mediator involved in the inflammatory process including celiac disease. ELISA technique was used to evaluate the serum level of sIL-2R, anti- tissue tTG IgA and anti-deamidated gliadin peptide (DGP) IgG. The duodenal histological changes were evaluated dependent on the MARSH grading system. Forty five patients were included in this cross-sectional study with other 45 healthy persons as control group. Statistical analysis using the SPSS system revealed the followings facts. Aim: This study aimed to assess the level of sIL-2R in association with duodenal histopathological changes in CD together with other serological and clinical parameters in comparison with healthy individuals (control group). Materials and Methods: A forty five patients were included in this cross-sectional study with other forty five healthy persons as control group. Statistical analysis using the SPSS system to reveal the followings facts. Results: Anemia was present in most of patients. The patients with celiac disease had high levels of serum anti-tTG, DGP & s.IL-2 receptors with significant difference in comparison with the control group (P< 0.05). MARSH grades were highly significant with the immunological markers. Conclusion: CD can be a hidden disease with variable severity modes that can be monitored by immunological and pathological methods. Soluble IL-2R antibody is a good tool to assess CD activity and patient compliance.

B-062 A Self-Imposed Gray Area? Analysis of Anti-Tissue Transglutaminase and Anti-Endomysial Antibody Discordance in a Celiac Disease Screening Serology Testing Algorithm

Abstract Background Celiac disease (CD) is an autoimmune enteropathy affecting around 1% of the population. While occasionally asymptomatic, the disease can present in a variety of ways and can be triggered by dietary gluten at any age. CD serology, including anti-tissue transglutaminase (anti-tTG) IgA and/or IgG, anti-endomysial antibody IgA and/or IgG, and anti-deamidated gliadin peptide IgA and/or IgG, is a key tool for CD screening, diagnosis, and monitoring. Of these tests, the clinical utility of anti-EMA testing has been questioned due to its high cost and limited sensitivity: 5–10% of CD patients do not test positive for anti-EMA and a negative anti-EMA does not rule out CD. The objective of this study is to: 1) evaluate the concordance between anti-tTG and anti-EMA serology test results, and 2) assess the clinical validity of our current CD reflex testing algorithm in which every positive anti-tTG test result goes on for anti-EMA testing. Methods Using our laboratory’s information system, we conducted a retroactive study on patients who underwent CD serology testing at our institution. Query was performed for all patient data [pediatric (<18 years) and adult (>18 years)] collected between April 2020 and August 2022 for anti-tTG IgA performed on the BioPlex 2200 (BioRad Laboratories Inc., Hercules, CA) and anti-EMA IgA (Euroimmun, Germany) (N = 124 308). Vendor-supplied clinical sensitivity and specificity are as follows: anti-tTG IgA 94.3% sensitivity, 98.8% specificity; anti-EMA IgA 95.3% sensitivity and 98.0% specificity. Results From our data, we calculated a mean positive agreement between our anti-tTG IgA and anti-EMA test results of 53.2% (95% confidence interval (CI) 47.5–58.8%) for all anti-tTG IgA positive cases (N = 6691, 5.4% of total anti-tTG IgA test results). The agreement between anti-tTG IgA and anti-EMA test results is improved if multiples of the upper limit of normal (ULN) for anti-tTG IgA is applied. The mean positive agreement between anti-tTG IgA and anti-EMA test results when the anti-tTG result is >10x ULN is 98.4% (95% CI 97.7–99.2%). However, if an anti-tTG IgA cutoff of <10x ULN is employed a mean positive agreement of 32.3% (95% CI 25.8–38.7%) is observed. At an anti-tTG IgA cutoff of <3x ULN, the mean positive agreement is just 11.8% (95% CI 8.2–15.4%). These findings are consistent in both pediatric (N = 29 381) and adult (N = 94 961) populations and are problematic as 45.4% of our positive anti-tTG IgA test results are accompanied by a negative anti-EMA. Conclusion The agreement between anti-tTG IgA and anti-EMA is dependent on the value of anti-tTG IgA with greater agreement observed with increasing anti-tTG IgA values. As all specimens at our institution with positive anti-tTG IgA test results are automatically reflexed for anti-EMA testing, has led to physician confusion as the majority of patients are falling into a gray area with conflicting CD serology test results. Our algorithm is also out of line with most CD screening guidelines that suggest an initial positive anti-tTG test result is followed up with biopsy. Finally, discontinuing anti-EMA reflex testing could result in cost savings of approximately $120 000 CAD per year.

Assessment of autoantibodies in paediatric population with primary immunodeficiencies: a pilot study

BackgroundThe correlation between primary immunodeficiencies (PIDs) and autoimmunity shows ethnic and geographical diversity. The aim of our study was to accumulate more data in paediatric PID population.Methods58 children aged 1–17 and with PID (study group) and 14 age-matched immunocompetent individuals (control group) were included in the study. Serum levels of 17 different specific IgG antibodies against autoantigens were measured by means of a quantitative enzyme immunoassay. Immunoglobulin levels were analysed in relation to a detailed medical examination.ResultsAutoantibodies against one or more antigens were detected in the sera of 24.14% (n = 14) subjects in the study group. The most frequent were anti-thyroid peroxidase (anti-TPO) antibodies (n = 8; 13.8%). Anti-TPO antibody levels were elevated more often in PID patients with a positive family history of autoimmune diseases (p = 0.04). The screening for anti-deamidated gliadin peptide (DGP) and anti-tissue transglutaminase (tTG) antibodies in our series allowed identifying two previously undiagnosed cases of coeliac disease in PID patients. There was no statistically significant difference between the study and the control group in terms of the autoantibodies prevalence.ConclusionsThis study provides data on the prevalence of autoantibodies in paediatric population diagnosed with PID. Selected autoantibodies (i.e. anti-tTG, anti-DGP) might be useful for the screening of PID to avoid the delay of diagnosis of an autoimmune disease.

Mode of presentation and performance of serology assays for diagnosing celiac disease: A single-center study in the United Arab Emirates.

To characterize patients with celiac disease (CD), examines the clinical spectrum of CD, and evaluate the performance of serologic tests used for CD screening, in the United Arab Emirates (UAE). Medical charts of patients received at the Digestive Diseases Institute of Cleveland Clinic Abu Dhabi from January 2015 to December 2020 were reviewed. Patients who were screened for four serologic biomarkers (anti-tissue transglutaminase IgA [Anti-tTG-IgA], anti-tissue transglutaminase IgG [Anti-TtG-IgG], anti-deamidated gliadin peptide IgG [Anti-DGP-IgG], and anti-deamidated gliadin peptide IgA [Anti-DGP-IgA]) were included. Histopathology was performed on patients with the seropositive test. Marsh score > 1 considered to confirm CD. Characteristics of the Anti-tTG-IgA seropositive patients were described and that correlated with histopathologically confirmed CD were explored. Of the 6,239 patients, 1.4, 2.9, 4.7, and 4.9%, were seropositive to Anti-tTG-IgG, Anti-TtG-IgA, Anti-DGP-IgA, and Anti-DGP-IgG, respectively. Overall, 7.7% were seropositive to either of the four biomarkers. Of the biopsy-screened 300 patients, 38.7% (1.9% of the total serologically screened) were confirmed with CD. The mean age of Anti-TtG-IgA seropositive patients was 32.1 ± 10.3 SD years, 72% of them were females, and 93.4% were Emirati. In those patients, overweight (28.7%) and obesity (24.7%) were common while 5.8% of patients were underweight. Anemia prevalence was 46.7%, 21.3% had Gastroesophageal reflux disease (GERD), 7.7% with autoimmune thyroid disease, 5.5% (type 1), and 3.3% (type 2) were diabetic. Vitamin D deficiency was observed in 47.8% of the Anti-TtG IgA seropositive patients. Twelve (10.3%) histopathologically confirmed CD patients were seronegative to Anti-TtG-IgA but seropositive to anti-DGP-IgA and/or Anti-DGP-IgG. Body mass index, GERD, autoimmune thyroid disease, type 1 diabetes, asthma, hemoglobin, and vitamin D concentration, were all correlated with biopsy-confirmed CD (P < 0.05). Compared to the gold-standard biopsy test, Anti-TtG-IgA had the highest sensitivity (89.7%) and specificity (83.7%). Three and two of every 100 patients were serologically (anti-tTG-IgA positive) and histopathologically diagnosed with CD, respectively. Although Anti-TtG-IgA is the most sensitive, specific, and commonly used test, one of every ten histopathologically confirmed patients and Anti-tTG-IgA seronegative were seropositive to Anti-DGP. To avoid missing patients with CD, a comprehensive serological investigation covering DGP-IgG/IgA is warranted.

Performance Assessment of a Novel Multianalyte Methodology for Celiac Disease Biomarker Detection and Evaluation of the Serology-Alone Criteria for Biopsy-Free Diagnosis.

Serology plays a vital role in celiac disease (CD) diagnosis, and the latest European guidelines advocate for biopsy-free diagnoses in patients with ≥10× the upper limit of normal (ULN) of anti-tissue transglutaminase (tTG) immunoglobulin A (IgA) antibodies. To assess performance characteristics of a novel automated particle-based multianalyte technology (Aptiva) for anti-tTG and anti-deamidated gliadin peptide (DGP) antibody detection as compared to the traditional enzyme-linked immunosorbent assay (QUANTA Lite). Performance characteristics of the ≥10× ULN anti-tTG IgA criteria for serologic diagnosis of CD were also evaluated. Sera samples from 703 patients were tested for anti-tTG IgA, anti-tTG immunoglobulin G (IgG), anti-DGP IgA, and anti-DGP IgG antibodies on both platforms. In total, 127 patients had medical information and were classified as CD-positive (n = 58) and CD-negative (n = 69) based on biopsy results. Clinical performance characteristics were evaluated. Anti-tTG IgA detection showed equal clinical sensitivity and specificity of 91% sensitivity and 99% specificity on both platforms. Anti-tTG IgG resulted in moderate sensitivity of 69% and 72%, but high specificity of 100% and 94% on Aptiva and QUANTA Lite, respectively. Anti-DGP IgG displayed comparable sensitivity of 90% and 81%, and a specificity of 94% and 99%, on Aptiva and QUANTA Lite, respectively. Anti-DGP IgA demonstrated greater sensitivity on QUANTA Lite (83%) than Aptiva (69%) and similar specificities of 97% and 98% on QUANTA Lite and Aptiva, respectively. At ≥10× ULN levels for anti-tTG IgA, Aptiva displayed a sensitivity of 72% and a specificity of 100%, and QUANTA Lite showed a sensitivity of 69% and a specificity of 100%. Aptiva is a reliable method to measure CD biomarkers with reduced hands-on necessity and high-throughput capabilities. This study supports the use of a ≥10× ULN anti-tTG IgA biopsy-free approach for serologic diagnosis of CD.

Diagnostic performances of celiac disease serological tests among Saudi patients.

: The prevalence of celiac disease (CD) is relatively high in Saudi Arabia, and little is known about the accuracy of serological markers in the local population. This study aimed to assess the diagnostic performance of various serological markers for detecting CD in Saudi children and adults. We conducted a retrospective study of 148 CD patients and 512 controls to assess the diagnostic performances of IgA anti-tissue transglutaminase antibodies (TTG), IgG anti-TTG, IgA anti-deamidated gliadin peptide antibodies (anti-DGP), IgG anti-DGP, and endomysium antibodies (EMA). : Immunoglobulin A (IgA) anti-TTG was the most sensitive test [98.9% (95% confidence interval (CI) 94.1-99.8%)], while EMA was the most specific [100%, 95%CI 98.6-100%]. By applying the criteria of IgA anti-TTG titers ≥10 × upper limit of normal (ULN) and positive EMA, 57.3% of patients could have avoided intestinal biopsy. IgG anti-DGP test had a sensitivity of 85.9% (95% CI = 77.3-91.5%) and a specificity of 93.5% (95% CI = (90.0-95.9%). Titers of IgA anti-TTG, IgA anti-DGP, and IgG anti-DGP were higher in CD patients with the Marsh 3c class than in those with the Marsh 3b and Marsh 3a classes. IgG anti-TTG and IgA anti-DGP had no additional diagnostic value. : IgA anti-TTG and EMA are excellent CD markers in children and adults. The use of IgA anti-TTG titers ≥10 × ULN and positive EMA as criteria for CD diagnosis in children and adults might be a good alternative to intestinal biopsy.

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.

Spanish National Registry of Paediatric Coeliac Disease: Changes in the Clinical Presentation in the 21st Century.

Over the last several decades, there has been a tendency towards a predominance of less symptomatic forms of coeliac disease (CD) and an increase in the patient age at diagnosis. This study aimed to assess the clinical presentation and diagnostic process of paediatric CD in Spain. A nationwide prospective, observational, multicentre registry of new paediatric CD cases was conducted from January 2011 to June 2017. The data regarding demographic variables, type of birth, breast-feeding history, family history of CD, symptoms, height and weight, associated conditions, serological markers, human leukocyte antigen (HLA) phenotype, and histopathological findings were collected. In total, 4838 cases (61% girls) from 73 centres were registered. The median age at diagnosis was 4 years. Gastrointestinal symptoms were detected in 71.4% of the patients, and diarrhoea was the most frequent symptom (45.9%). The most common clinical presentation was the classical form (65.1%) whereas 9.8% ofthe patients were asymptomatic. There was a trend towards an increase in the age at diagnosis, proportion of asymptomatic CD cases, and usage of anti-deamidated gliadin peptide antibodies and HLA typing for CD diagnosis. There was, however, a decreasing trend in the proportion of patients undergoing biopsies. Some of these significant trend changes may reflect the effects of the 2012 ESPGHAN diagnosis guidelines. Paediatric CD in Spain is evolving in the same direction as in the rest of Europe, although classical CD remains the most common presentation form, and the age at diagnosis remains relatively low.

Diagnostic Value of Immunoglobulin G Anti-Deamidated Gliadin Peptide Antibody for Diagnosis of Pediatric Celiac Disease: A Study from Shiraz, Iran.

PurposeScreening serologic tests are important tools for the diagnosis of celiac disease (CD). Immunoglobulin (Ig)G anti-deamidated gliadin peptide (anti-DGP) is a relatively new autoantibody thought to have good diagnostic accuracy, comparable to that of anti-tissue transglutaminase (anti-tTG) antibody.MethodsPediatric patients (n=86) with a clinical suspicion of CD were included. Duodenal biopsy, anti-tTG, and IgG anti-DGP antibody tests were performed. The patients were divided into CD and control groups based on the pathological evaluation of duodenal biopsies. The diagnostic accuracy of serological tests was determined.ResultsIgA anti-tTG and IgG anti-DGP antibodies were positive in 86.3% and 95.4% of patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the IgA anti-tTG test were 86.3%, 50.0%, and 68.6%, respectively, and those of the IgG anti-DGP test were 95.4%, 85.7%, and 90.7%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.84 (95% confidence interval [CI], 0.74–0.91) for IgA anti-tTG test and 0.93 (95% CI, 0.86–0.97) for IgG anti-DGP test. The comparison of IgA anti-tTG and IgG anti-DGP ROC curves showed a higher sensitivity and specificity of the IgG anti-DGP test.ConclusionIgG anti-DGP is a reliable serological test for CD diagnosis in children. High tTG and DGP titers in the serum are suggestive of severe duodenal atrophy. The combined use of IgA anti-tTG and IgG anti-DGP tests for the initial screening of CD can improve diagnostic sensitivity.

Diagnostic Accuracy of IgA Anti-Transglutaminase and IgG Anti-Deamidated Gliadin for Diagnosis of Celiac Disease in Children under Two Years of Age: A Systematic Review and Meta-Analysis.

The need of adding the determination of anti-deamidated gliadin peptide (DGP) IgG to anti-transglutaminase (TTG) IgA antibodies for diagnosis of celiac disease (CD) in children <2 years of age is controversial. We performed a systematic review and meta-analysis to evaluate, by head-to-head comparison, the diagnostic accuracy of TTG IgA and DGP IgG antibodies. We searched PubMed, MEDLINE, and Embase databases up to January 2021. The diagnostic reference was intestinal biopsy. We calculated the sensitivity and specificity of these tests and the odds ratio (OR) between the tests. Fifteen articles were eligible for the systematic review and ten were eligible for the meta-analysis. Sensitivity and specificity were 0.96 (95% confidence interval (CI), 0.91–0.98) and 0.96 (95% CI, 0.85–0.99) for DGP IgG and 0.93 (95% CI, 0.88–0.97) and 0.98 (95% CI, 0.96–0.99) for TTG IgA, respectively. TTG IgA specificity was significantly higher (OR 9.3 (95% CI, 2.3–37.49); p < 0.001) while the sensitivity of DGP IgG was higher without reaching statistical significance (OR: 0.6 (95% CI, 0.24–1.51); p = 0.28). Both the meta-analysis and the systematic review showed that some children with early CD are missed without the DGP IgG test. In children <2 years of age, TTG IgA is the best CD screening test; however, the addition of DGP IgG may increase the diagnostic sensitivity.

Prevalence of Coeliac Disease in Omani Adults with Iron Deficiency Anaemia of Unknown Cause: Case-finding study.

ObjectivesThis study aimed to estimate the serological prevalence of coeliac disease in patients with iron deficiency anaemia (IDA) of unknown cause at a primary healthcare facility in Oman.MethodsThis prospective case-finding study was conducted at the primary care clinics in Sultan Qaboos University Hospital, Muscat, Oman from September 2018 to June 2020. Patients aged 18 to 55 years, with a haemoglobin (Hb) level <11.5 g/dL for males and <11.0 g/dL for females and a ferritin level <30 ng/mL for males and <13 ng/mL for females, were included in the study. Blood samples were obtained for initial serological screening using serum immunoglobulin (Ig)A level; those samples with normal levels of IgA, IgA anti-tissue transglutaminase antibody (tTG) and IgA anti-deamidated gliadin peptide (DGP) were determined. Positive IgA-tTG test was confirmed using IgA-endomysial antibodies. Patients with low IgA levels were tested using IgG-tTG and IgG-DGP.ResultsA total of 104 patients participated in this study. Eight patients (7.7%) were found to have a positive serological screening result for coeliac disease; of these patients, three (37.5%) had a positive IgA-tTG result. Two of those three (66.7%) had a positive IgA-endomysial antibody. The IgA-DGP result was positive in seven (6.7%) of the 104 patients. Out of those seven patients, two also had a positive IgA tTG.ConclusionCoeliac disease is not a rare disorder. There is a need to increase awareness among healthcare professionals about coeliac disease and its non-classical manifestations such as IDA.

The Differences between Gluten Sensitivity, Intestinal Biomarkers and Immune Biomarkers in Patients with First-Episode and Chronic Schizophrenia.

Schizophrenia is a heterogeneous disorder without a fully elucidated etiology and mechanisms. One likely explanation for the development of schizophrenia is low-grade inflammation, possibly caused by processes in the gastrointestinal tract related to gluten sensitivity. The aims of this study were to: (1) compare levels of markers of gluten sensitivity, inflammation and gut permeability, and (2) determine associations between gluten sensitivity, inflammation, and intestinal permeability in patients with first-episode/chronic (FS/CS) schizophrenia and healthy individuals (HC). The total sample comprised 162 individuals (52 FS; 50 CS, and 60 HC). The examination included clinical variables, nutritional assessment, and serum concentrations of: high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble CD14 (sCD14), anti-Saccharomyces cerevisiae antibody (ASCA), antigliadin antibodies (AGA) IgA/IgG, antibodies against tissue transglutaminase 2 (anti-tTG) IgA, anti-deamidated gliadin peptides (anti-DGP) IgG. A significant difference between groups was found in sCD14, ASCA, hs-CRP, IL-6 and AGA IgA levels. AGA IgG/IgA levels were higher in the FS (11.54%; 30.77%) and CS (26%; 20%) groups compared to HC. The association between intestinal permeability and inflammation in the schizophrenic patients only was noted. The risk for developing schizophrenia was odds ratio (OR) = 4.35 (95% confidence interval (CI 1.23–15.39) for AGA IgA and 3.08 (95% CI 1.19–7.99) for positive AGA IgG. Inflammation and food hypersensitivity reactions initiated by increased intestinal permeability may contribute to the pathophysiology of schizophrenia. The immune response to gluten in FS differs from that found in CS.

Measures of gluten-related reactivity in children with autism spectrum disorders in the absence of overt gastrointestinal symptoms: a pilot study from the United Arab Emirates.

ObjectivesThe aetiology of autism spectrum disorder (ASD) is multifactorial, sometimes genetic, and may be associated with abnormal immunological responses to peptides from proteins such as gluten. These peptides may cross the blood-brain barrier and affect neurotransmission, resulting in behavioural symptoms consistent with ASD. The aim of this study was to screen for markers of gluten-related immune reactivity in the absence of overt gastrointestinal symptoms in patients with ASD in the United Arab Emirates, a country associated with a high prevalence of ASD but lacking this type of research.MethodsPatients diagnosed with ASD (using Diagnostic and Statistical Manual of Mental Disorders-IV-based criteria and Autism Diagnostic Observational Schedules) were compared with controls, regarding anti-tissue transglutaminase (tTG) immunoglobulin (Ig) A and anti-deamidated gliadin peptide (DGP) IgA levels.ResultsSixty-six patients with ASD and 101 controls were included. Patients with ASD showed statistically significant lower anti-DGP IgA levels, but no significant difference in anti-tTG IgA levels, versus healthy controls. Correlations between immunological data and clinical symptoms were synergistic, but not statistically significant.ConclusionASD may be associated with reduced levels of anti-DGP IgA.

Celiac Dietary Adherence Test and Standardized Dietician Evaluation in Assessment of Adherence to a Gluten-Free Diet in Patients with Celiac Disease

Adherence to a gluten-free diet (GFD) is currently the mainstay of treatment strategy for celiac disease (CD). The aim of our study was measuring a GFD adherence in CD patients using two newly validated methods of dietary assessment—Standardized Dietician Evaluation (SDE) and the Celiac Dietary Adherence Test (CDAT). Ninety-two adults with CD were evaluated by a registered dietitian with extensive experience with the use of SDE and CDAT. Duodenal biopsy was performed and blood was drawn for serum anti-endomysial, anti-deamidated gliadin peptide and anti-tissue transglutaminase antibodies in forty four of those patients. The results of CDAT and SDE were very convergent, but SDE scores better correlated with serologic and histologic findings. As many as 24–52% of study participants did not adhere well enough to a GFD. Insufficient adherence to a GFD in CD patients is still a significant problem. The knowledge about gluten content in food ingredients and additives is very low among adults with CD. SDE is the most accurate method in assessing compliance with a GFD and is especially helpful in determining hidden sources of gluten. The CDAT may be a fast tool for screening for a GFD adherence in CD patients.

Non-invasive prediction of persistent villous atrophy in celiac disease.

BACKGROUNDCeliac disease (CD) is an immune-mediated enteropathy that is primarily treated with a gluten-free diet (GFD). Mucosal healing is the main target of the therapy. Currently, duodenal biopsy is the only way to evaluate mucosal healing, and non-invasive markers are challenging. Persistent elevation of anti-tissue transglutaminase antibodies (aTTG) is not an ideal predictor of persistent villous atrophy (VA). Data regarding prediction of atrophy using anti-deamidated gliadin peptide antibodies (aDGP) and abdominal ultrasonography are lacking.AIMTo evaluate the ability of aTTG, aDGP, small bowel ultrasonography, and clinical and laboratory parameters in predicting persistent VA determined using histology.METHODSPatients with CD at least 1 year on a GFD and available follow-up duodenal biopsy, levels of aTTG and aDGP, and underwent small bowel ultrasonography were included in this retrospective cohort study. We evaluated the sensitivity, specificity, and positive and negative predictive values of aTTG, aDGP, small bowel ultrasonography, laboratory and clinical parameters to predict persistent VA. A receiver operating characteristic (ROC) curve analysis of antibody levels was used to calculate cut off values with the highest accuracy for atrophy prediction.RESULTSComplete data were available for 82 patients who were followed up over a period of four years (2014-2018). Among patients included in the analysis, women (67, 81.7%) were predominant and the mean age at diagnosis was 33.8 years. Follow-up biopsy revealed persistent VA in 19 patients (23.2%). The sensitivity and specificity of aTTG using the manufacturer’s diagnostic cutoff value to predict atrophy was 50% and 85.7%, respectively, while the sensitivity and specificity of aDGP (using the diagnostic cutoff value) was 77.8% and 75%, respectively. Calculation of an optimal cutoff value using ROC analysis (13.4 U/mL for aTTG IgA and 22.6 U/mL for aDGP IgA) increased the accuracy and reached 72.2% [95% confidence interval (CI): 46.5-90.3] sensitivity and 90% (95%CI: 79.5-96.2) specificity for aDGP IgA and 66.7% (95%CI: 41.0-86.7) sensitivity and 93.7% (95%CI: 84.5-98.2) specificity for aTTG IgA. The sensitivity and specificity of small bowel ultrasonography was 64.7% and 73.5%, respectively. A combination of serology with ultrasound imaging to predict persistent atrophy increased the positive predictive value and specificity to 88.9% and 98% for aTTG IgA and to 90.0% and 97.8% for aDGP IgA. Laboratory and clinical parameters had poor predictive values.CONCLUSIONThe sensitivity, specificity, and negative predictive value of aTTG and aDGP for predicting persistent VA improved by calculating the best cutoff values. The combination of serology and experienced bowel ultrasound examination may achieve better accuracy for the detection of atrophy.