Anti-transglutaminase antibodies in non-coeliac children suffering from infectious diseases

Viruses and celiac disease: what do we know ?

The aim of this review is to provide a comprehensive overview about the link between viruses and celiac disease. A systematic search on PubMed, Embase, and Scopus was conducted on March 07, 2023. The reviewers independently selected the articles and chose which articles to include. The review is a textual systemic review, and all relevant articles were included based on title and abstract. If there was a disagreement between the reviewers, they came to a consensus during deliberation sessions. A total of 178 articles were selected for the review and read in full; only part of them was retained. We found studies between celiac disease and 12 different viruses. Some of the studies were done only on small groups. Most studies were on pediatric population. Evidence for an association was found with several viruses (trigger or protective). It seems that only a part of the viruses could induce the disease. Several points are important to keep in mind: firstly, simple mimicry or that the virus induces a high level of TGA is not sufficient to promote the disease. Secondly, inflammatory background is necessary to induce CD with virus. Thirdly, IFN type 1 seems to have an important role. Some of the viruses are potential or known triggers like enteroviruses, rotaviruses, reoviruses, and influenza. Further studies are needed to better understand the role of viruses in celiac disease to better treat and prevent the disease.

Falsely elevated anti-tissue transglutaminase antibodies in patients with immunoproliferative small intestinal diseases: A case series

Immunoproliferative small intestinal disease (IPSID) is an uncommon disease of the small intestine. There is a similarity in the clinical presentations of enteropathic diseases, including celiac disease, tropical sprue, IPSID, and Whipple's disease. A differentiation between them is based on the use of a highly specific serological test for celiac disease and specific histological characteristics. We found that IgA-anti-tissue transglutaminase antibody (IgA-tTG Ab) is falsely elevated in a subset of patients with IPSID. The levels of IgA-tTG Ab fall with the treatment of IPSID. The healthcare professional should be aware of the conditions that lead to a false-positive anti-tTG Ab. Intestinal mucosal biopsies even in the presence of anti-tTG Ab should be done in endemic regions as they provide an opportunity for making a diagnosis of alternative and uncommon diseases before the diagnosis of celiac disease.

The risk for celiac disease after Covid-19 infection

BACKGROUND

Celiac disease (CD) is an autoimmune disease leading to gastrointestinal symptoms and mineral deficiencies. The pathogenetic mechanisms, besides the clear HLA association, are elusive. Among environmental factors infections have been proposed. Covid-19 infection results in a systemic inflammatory response that often also involves the gastrointestinal tract. The aim of the present study was to investigate whether Covid-19 infection could increase the risk for CD.

PATIENTS AND METHODS

All patients, both children and adults, in the county Skåne (1.4 million citizens) in southern Sweden with newly diagnosed biopsy- or serology-verified CD or a positive tissue transglutaminase antibody test (tTG-ab) during 2016-2021 were identified from registries at the Departments of Pathology and Immunology, respectively. Patients with a positive Covid-19 PCR or antigen test in 2020 and 2021 were identified from the Public Health Agency of Sweden.

RESULTS

During the Covid-19 pandemic (March 2020 - December 2021), there were 201 050 cases of Covid-19 and 568 patients with biopsy- or serology-verified CD or a first-time positive tTG-ab tests, of which 35 patients had been infected with Covid-19 before CD. The incidence of verified CD and tTG-ab positivity was lower in comparison to before the pandemic (May 2018 - February 2020; 22.5 vs. 25.5 cases per 100 000 person-years, respectively, incidence rate difference (IRD) -3.0, 95% CI -5.7 - -0.3, p = 0.028). The incidence of verified CD and tTG-ab positivity in patients with and without prior Covid-19 infection was 21.1 and 22.4 cases per 100 000 person-years, respectively (IRD - 1.3, 95% CI -8.5-5.9, p = 0.75).

CONCLUSIONS

Our results indicate that Covid-19 is not a risk factor for CD development. While gastrointestinal infections seem to be an important part of the CD pathogenesis, respiratory infections probably are of less relevance.

Effect of helicobacter pylori infection eradication on serum level of anti-tissue transglutaminase in children with celiac disease

BACKGROUND

Evidence shows the increase of anti-tissue transglutaminase (tTG) levels in various conditions, including infectious agents, independently of celiac disease (CD). The aim of this study was to investigate the effect of helicobacter pylori (H.pylori) infection eradication on serum level of tTG in children with CD.

METHODS

This study was conducted on children aged 2 to 18 who referred to reference hospitals for diagnosis of CD. After upper endoscopy and biopsy to confirm CD and H.pylori infection, the children were divided into three groups (including group one: 16 CD patients with positive H. pylori; group two: 16 non-CD patients with positive H. pylori; and group three: 56 CD patients with negative H. pylori), respectively. The tTG level in study groups were compared after the eradication of H.pylori.

RESULTS

The mean age of the subjects in the group one, two, and three was 9.7 ± 3.33, 11.8 ± 3.14, and 7.6 ± 3.32 years, respectively. Our results showed that in group one, mean tTG increased after eradication of H.pylori infection, however, these changes were not significant (182.43 vs. 157.18, P = 0.121). In the second group, although unlike the first group, mean tTG decreased after eradication of the infection, but still these changes were not significant (9.56 vs. 22.18, P = 0.449). Furthermore, at the baseline level, the mean tTG in the group three was closer to the mean tTG in the first group.

CONCLUSION

Our findings showed that the eradication of H.pylori infection does not have a significant effect on tTG levels in children with and without CD.

Single-Cell RNA Sequencing of Peripheral Blood Mononuclear Cells From Pediatric Coeliac Disease Patients Suggests Potential Pre-Seroconversion Markers

Celiac Disease (CeD) is a complex immune disorder involving villous atrophy in the small intestine that is triggered by gluten intake. Current CeD diagnosis is based on late-stage pathophysiological parameters such as detection of specific antibodies in blood and histochemical detection of villus atrophy and lymphocyte infiltration in intestinal biopsies. To date, no early onset biomarkers are available that would help prevent widespread villous atrophy and severe symptoms and co-morbidities. To search for novel CeD biomarkers, we used single-cell RNA sequencing (scRNAseq) to investigate PBMC samples from 11 children before and after seroconversion for CeD and 10 control individuals matched for age, sex and HLA-genotype. We generated scRNAseq profiles of 9559 cells and identified the expected major cellular lineages. Cell proportions remained stable across the different timepoints and health conditions, but we observed differences in gene expression profiles in specific cell types when comparing patient samples before and after disease development and comparing patients with controls. Based on the time when transcripts were differentially expressed, we could classify the deregulated genes as biomarkers for active CeD or as potential pre-diagnostic markers. Pathway analysis showed that active CeD biomarkers display a transcriptional profile associated with antigen activation in CD4+ T cells, whereas NK cells express a subset of biomarker genes even before CeD diagnosis. Intersection of biomarker genes with CeD-associated genetic risk loci pinpointed genetic factors that might play a role in CeD onset. Investigation of potential cellular interaction pathways of PBMC cell subpopulations highlighted the importance of TNF pathways in CeD. Altogether, our results pinpoint genes and pathways that are altered prior to and during CeD onset, thereby identifying novel potential biomarkers for CeD diagnosis in blood.

Repeat Biopsy to Assess Duodenal Healing in Children With Celiac Disease and Eosinophilic Gastrointestinal Disorders

The aim of the study was to determine the correlation between duodenal mucosal biopsies and tissue transglutaminase immunoglobulin A (tTG-IgA) levels in pediatric patients with biopsy-confirmed celiac disease (CD) and eosinophilic gastrointestinal disorders (EGID) who have had repeat duodenal biopsies after initiating a gluten-free diet.

Methods

A retrospective chart review was performed of children with CD and EGID seen at the Children's Hospital of Philadelphia between 2003 and 2018. Data collected included duodenal biopsy pathology, celiac serology including tTG-IgA, and symptom reports. Duodenal healing was defined as normal villous architecture and no intraepithelial lymphocytes. These data were compared with tTG-IgA level. Data were analyzed with Fisher exact test and t test methods.

Results

Thirty-nine patients had normal IgA and diagnoses of both CD and EGID. At second biopsy, 44% (17/39) of patients showed no histologic evidence of active CD and 36% (14/39) of patients had negative tTG-IgA values. Sixty percent (9/15) of patients with no evidence of CD on biopsy had abnormal tTG-IgA levels, and 57% (8/14) of patients with normal tTG-IgA levels had evidence of active disease on biopsy.

Conclusions

The data show that an abnormal tTG-IgA drawn after initiation of a gluten-free diet is not correlated with duodenal mucosal injury in pediatric patients with CD and EGID. This suggests that serologic surveillance with tTG-IgA is not sufficient to monitor CD intestinal healing in this patient cohort. Persistent elevations of tTG-IgA in CD patients with normal duodenal biopsies should prompt investigation into other potential causes.

Low Titer Tissue Transglutaminase Antibodies: A Link to Helicobacter pylori Infection?

INTRODUCTION

Low serum titer of anti-tissue transglutaminase (tTG) has been described in various conditions without any evidence of celiac disease (CD). Infectious agents have been suggested to trigger autoimmunity and promote the production of anti-tTG. The aim of this study was to investigate if there is a link between a positive celiac serology and concomitant Helicobacter pylori infection in children.

METHODS

The data of 178 pediatric patients who underwent upper gastrointestinal endoscopy due to positive celiac serology were compiled. The patients whose histopathologic findings were not consistent with CD were followed on gluten-containing diet. The changes in the serum level of anti-tTG IgA on the follow-up were compared between H. pylori-infected and noninfected patients after the eradication of H. pylori.

RESULTS

Of 155 patients who met the inclusion criteria, 119 (group 1) were diagnosed as CD, and duodenal histopathology of the remaining 36 children (group 2) was not compatible with CD. In group 2, 11 out of 36 (30.5%) patients were infected with H. pylori. After the eradication of H. pylori, anti-tTG IgA level either decreased or dropped below cutoff value in 9/11 (81%) patients while it was 20% in those who were not infected with H. pylori in the 6th month of the follow-up (p = 0.001).

CONCLUSION

Our results suggest that H. pylori infection may be the cause of false or transient positive celiac serology. Thus, a positive celiac serology should be carefully interpreted in the presence of H. pylori infection before confirming the diagnosis of this life-long disease.

Molecular Biomarkers for Celiac Disease: Past, Present and Future

Celiac disease (CeD) is a complex immune-mediated disorder that is triggered by dietary gluten in genetically predisposed individuals. CeD is characterized by inflammation and villous atrophy of the small intestine, which can lead to gastrointestinal complaints, malnutrition, and malignancies. Currently, diagnosis of CeD relies on serology (antibodies against transglutaminase and endomysium) and small-intestinal biopsies. Since small-intestinal biopsies require invasive upper-endoscopy, and serology cannot predict CeD in an early stage or be used for monitoring disease after initiation of a gluten-free diet, the search for non-invasive biomarkers is ongoing. Here, we summarize current and up-and-coming non-invasive biomarkers that may be able to predict, diagnose, and monitor the progression of CeD. We further discuss how current and emerging techniques, such as (single-cell) transcriptomics and genomics, can be used to uncover the pathophysiology of CeD and identify non-invasive biomarkers.

[Infections in early life as risk factor for coeliac disease]

INTRODUCTION

Among the environmental factors that can affect the pathological response to gluten in coeliac disease (CD), the factors that influence the immune response, such as infections and use of antibiotics, are proposed. Our objective is to determine the relationship between infections in early life and the risk of CD.

PATIENTS AND METHODS

A retrospective case-control study, including patients aged 0-16 years with a diagnosis of CD was performed between the years 2014-2018. An analysis was made of documented infections in the first 6 months of life, types of infection (respiratory, gastrointestinal, urinary, others), microorganisms involved, and antibiotic therapy used.

RESULTS

A total of 93 coeliac patients, 93 controls, and 237 infectious episodes were registered. Documented infections affected 67.7% of coeliac patients and 50.5% of controls (P = .017), with a mean of 1.49 ± 1.53 episodes in the coeliac group and 1.05 ± 1.5 in the controls (P = .016). Documented infections in the first 6 months of life doubles the risk of developing CD (OR 2.05; 95% CI; 1.13-3.73), with this risk being higher for respiratory infections, which multiply the risk by 2.3 (OR 2.30, 95% CI; 1.28-4.14). Also, having 3 or more respiratory infections in the first 6 months of life multiplied the risk by 2.8 (OR 2.79, 95% CI; 1.03-7.54). No differences were found related to the types of involved microorganism or regarding the use of antibiotics.

CONCLUSIONS

Infections in the first 6 months of life increase the risk of developing CD, especially for respiratory infections and, to a greater extent, if 3 or more episodes occur. The use of antibiotics in this period of life has not been related to an increased risk of CD.

HLA-DQ genotype and biochemical characterization of anti-transglutaminase 2 antibodies in patients with type 1 diabetes mellitus in Taiwan

Human Leukocyte Antigen (HLA)-DQ2 and HLA-DQ8 are genetic risk factors for Type 1 Diabetes Mellitus (T1DM) and Celiac disease (CD) in Caucasians, but their association with Taiwanese Han population is unknown. We screened 532 Taiwanese T1DM patients for CD biomarkers including anti-tissue transglutaminase (TGM2), anti-gliadin and anti-neoepitope antibodies (Abs), sequencing DQB1 genotypes, and characterized the TGM2 Abs. We report that 3.76% of Taiwanese patients had TGM2-Abs and all had no CD's symptoms. In contrast to Caucasian's CD patients, DQ2/DQ8 only constituted ~4/5 of TGM2-Abs positive patients, while the other ~1/5 patients belonged to different HLA genotypes. Either anti-gliadin or anti-neoepitope Abs coexisted with ~3/4 of TGM2-Abs positive patients that were likely due to gluten-ingestion, while the cause of TGM2-Abs production for other ~1/4 of patients was unknown. Purified anti-TGM2 IgA (TGA) and anti-TGM2 IgG (TGG) could bind on endothelial cells surface, recognized native better than denatured forms of TGM2, and TGA inhibited TGM2's transamidation activity by up to 80% but TGG had no effects. Epitope mapping of all TGM2-Abs positive sera demonstrated that TGM2-Abs had heterogeneity in specificities. This is the first study on the differences between Taiwanese Han group and Caucasian in HLA genotypes and properties of TGM2-Abs.

Efficacy Study of Anti-Endomysium Antibodies for Celiac Disease Diagnosis: A Retrospective Study in a Spanish Pediatric Population

The aim of this study was to assess the efficacy of anti-endomysium antibodies (EMA) as a serological marker for celiac disease (CD) diagnosis in a pediatric population. A retrospective study of pediatric patients who underwent a CD serological markers study: EMA and anti-tissue transglutaminase antibodies (anti-TG2). Clinical symptomatology, degree of histological lesion, human leukocyte antigen (HLA) haplotype compatible with CD (HLA DQ2 and/or DQ8), and final diagnosis were taken into account. We included 445 patients who were classified in two groups according to the final diagnosis. Group 1: 232 children with CD, 91.4% of whom exhibited small intestinal villous atrophy, 228 being EMA-positive and four EMA-negative. Group 2: 213 children with a non-CD diagnosis, 212 EMA negative and one EMA positive. Both antibodies, EMA and anti-TG2, reached similar sensitivities, 98% and 99% respectively, while EMA had a higher specificity (99%) than anti-TG2 (93%). By using both markers combined, compared to using anti-TG2 alone, 5.7% of patients are better diagnosed. However, when we compare the efficacy of EMA and anti-TG2 in asymptomatic and symptomatic patients, the sensitivity of EMA is 98% irrespective of symptoms, thus higher than for anti-TG2 ≥10 × upper limit of normal (ULN) (respectively 77% and 84%). Our results support the use of EMA to increase CD diagnostic accuracy in a non-biopsy approach, especially in asymptomatic children.

A Functional Idiotype/Anti-Idiotype Network Is Active in Genetically Gluten-Intolerant Individuals Negative for Both Celiac Disease-Related Intestinal Damage and Serum Autoantibodies

An unbalance between Abs that recognize an autoantigen (idiotypes; IDs) and Igs that bind such Abs (anti-IDs) is considered a functional event in autoimmune disorders. We investigated the presence of an ID/anti-ID network in celiac disease (CD), a condition in which antitissue transglutaminase 2 (TG2) Abs are suspected to contribute to CD pathogenesis. To characterize the ID side, we reproduced by in vitro yeast display the intestine-resident Abs from CD and control patients. These TG2-specific IDs were used to identify potential anti-IDs in the serum. We observed elevated titers of anti-IDs in asymptomatic patients with predisposition to CD and demonstrated that anti-ID depletion from the serum restores a detectable humoral response against TG2. Our study provides an alternative approach to quantify CD-related autoantibodies in cases that would be defined "negative serology" with current diagnostic applications. Therefore, we suggest that developments of this technology could be designed for perspective routine tests.

Coeliac disease

Coeliac disease is an immune-mediated enteropathy against dietary gluten present in wheat, rye and barley and is one of the most common lifelong food-related disorders worldwide. Coeliac disease is also considered to be a systemic disorder characterized by a variable combination of gluten-related signs and symptoms and disease-specific antibodies in addition to enteropathy. The ingestion of gluten leads to the generation of harmful gluten peptides, which, in predisposed individuals, can induce adaptive and innate immune responses. The clinical presentation is extremely variable; patients may have severe gastrointestinal symptoms and malabsorption, extraintestinal symptoms or have no symptoms at all. Owing to the multifaceted clinical presentation, diagnosis remains a challenge and coeliac disease is heavily underdiagnosed. The diagnosis of coeliac disease is achieved by combining coeliac disease serology and small intestinal mucosal histology during a gluten-containing diet. Currently, the only effective treatment for coeliac disease is a lifelong strict gluten-free diet; however, the diet is restrictive and gluten is difficult to avoid. Optimizing diagnosis and care in coeliac disease requires continuous research and education of both patients and health-care professionals.

Anti-type 2 transglutaminase antibodies as modulators of type 2 transglutaminase functions: a possible pathological role in celiac disease

Auto-antibodies to the ubiquitous enzyme type-2 transglutaminase (TG2) are a specific hallmark of celiac disease (CD), a widely diffused, multi-factorial disease, affecting genetically predisposed subjects. In CD an inflammatory response, at the intestinal level, is triggered by diet consumption of gluten-containing cereals. Intestinal mucosa displays various degrees of atrophy and hyperplasia, with consequent global intestinal dysfunction and other relevant extra-intestinal symptoms. Through deamidation of specific glutamines of gluten-derived gliadin peptides, TG2 strongly enhances gliadin immunogenicity. In addition, TG2 cross-linking activity may generate complexes between TG2 itself and gliadin peptides, and these complexes seem to cause the auto-immune response by means of an apten-carrier-like mechanism of antigen presentation. Anti-TG2 antibodies can be early detected in the intestinal mucosa of celiac patients and are also abundantly present into the serum, thus potentially reaching other organs and tissues by blood circulation. Recently, the possible pathogenetic role of auto-antibodies to TG2 in CD has been investigated. Here, we report an overview about the genesis of these antibodies, their specificity, their modulating ability toward TG2 enzymatic or non-enzymatic activities and their biological effects exerted by interacting with extracellular TG2 or with cell-surface TG2. We also discuss the auto-immune response occurring in CD against other TG members (i.e. type 3 and type 6) and analyze the occurrence of anti-TG2 antibodies in other auto-immune CD-related diseases. Data now available let us to suppose that, even if antibodies to TG2 do not represent the triggering molecules in CD, they could be important players in disease progression and manifestations.

[Anti-tissue transglutaminase antibodies not related to gluten intake]

INTRODUCTION

Anti-tissue transglutaminase antibodies (tTG) have high specificity for coeliac disease (CD). However, positive anti-tTG antibodies have been described in non-coeliac patients. Aim To assess positive anti-tTG antibodies not related to gluten intake.

PATIENTS AND METHODS

Retrospective review and follow up conducted on patients with suspected CD (increase anti-tTG levels and gastrointestinal symptoms) but with atypical serology results, positive anti-tTG with gluten free diet and a decrease in anti-tTG levels despite gluten intake.

RESULTS

A total of 9 cases were reviewed in which 5 cases had Marsh 3 involvement in the initial biopsy, and were diagnosed with CD (Group A). They began a gluten free diet and also a cow's milk protein (CMP) free diet because of their nutritional status. When CMP was re-introduced, anti-tTG increased, and returned to normal after the CMP was withdrawn again. The other 4 patients had a normal initial biopsy (Group B). Gluten was not removed from their diet, but they started a CMP free diet because a non IgE mediated CMP allergy was suspected. Symptoms disappeared, and anti-tTG was normal after CMP free diet with gluten intake. All the patients had susceptibility haplotype HLA DQ2/DQ8.

CONCLUSIONS

CMP ingestion after an exclusion diet can induce an increase in anti-tTG in some coeliac subjects. CMP can produce this immune response if there were no gluten transgressions. This response has also been observed in non-IgE mediated CMP allergy patients with the susceptibility haplotype HLA DQ2/DQ8.

Clinical usefulness of serum antibodies as biomarkers of gastrointestinal and liver diseases

The progressively growing knowledge of the pathophysiology of a number of immune-mediated gastrointestinal and liver disorders, including autoimmune atrophic gastritis, coeliac disease, autoimmune enteropathy, inflammatory bowel disease, autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cholangitis and autoimmune pancreatitis, together with the improvement of their detection methods have increased the diagnostic power of serum antibodies. In some cases - coeliac disease and autoimmune atrophic gastritis - they have radically changed gastroenterologists' diagnostic ability, while in others - autoimmune hepatitis, inflammatory bowel disease and autoimmune pancreatitis - their diagnostic performance is still inadequate. Of note, serum antibody misuse in clinical practice has raised a number of controversies, which may generate confusion in the diagnostic management of the aforementioned disorders. In this review, we critically re-evaluate the usefulness of serum antibodies as biomarkers of immune-mediated gastrointestinal and liver disorders, and discuss their pitfalls and merits.

Strategies to improve the efficiency of celiac disease diagnosis in the laboratory

The demand for testing to detect celiac disease (CD) autoantibodies has increased, together with the cost per case diagnosed, resulting in the adoption of measures to restrict laboratory testing. We designed this study to determine whether opportunistic screening to detect CD-associated autoantibodies had advantages compared to efforts to restrict testing, and to identify the most cost-effective diagnostic strategy. We compared a group of 1678 patients in which autoantibody testing was restricted to cases in which the test referral was considered appropriate (G1) to a group of 2140 patients in which test referrals were not reviewed or restricted (G2). Two algorithms A (quantifying IgA and Tissue transglutaminase IgA [TG-IgA] in all patients), and B (quantifying only TG-IgA in all patients) were used in each group, and the cost-effectiveness of each strategy was calculated. TG-IgA autoantibodies were positive in 62 G1 patients and 69 G2 patients. Among those positive for tissue transglutaminase IgA and endomysial IgA autoantibodies, the proportion of patients with de novo autoantibodies was lower (p=0.028) in G1 (11/62) than in G2 (24/69). Algorithm B required fewer determinations than algorithm A in both G1 (2310 vs 3493; p<0.001) and G2 (2196 vs 4435; p<0.001). With algorithm B the proportion of patients in whom IgA was tested was lower (p<0.001) in G2 (29/2140) than in G1 (617/1678). The lowest cost per case diagnosed (4.63 euros/patient) was found with algorithm B in G2. We conclude that opportunistic screening has advantages compared to efforts in the laboratory to restrict CD diagnostic testing. The most cost-effective strategy was based on the use of an appropriate algorithm.

Clinical and biological correlations in celiac disease in children: the prospective single experience of a romanian tertiary center: A case-control study (Strobe-Compliant study)

Celiac disease-a chronic inflammatory disease of the intestine-is triggered by gluten or associated protein consumption.The aim of our study was to assess the sensitivity, specificity of the combined anti-transglutaminase 2 (TG2)/deamidated gliadin peptide antibodies (DGP), and antiendomisium antibodies (EMA), to determine the distribution of HLA-DQ2/DQ8 for the 140 tested patients, and also to evaluate the clinical and laboratory characteristics of patients admitted with the suspicion of celiac disease (CD). Children included in the study were divided into: group 1, patients with confirmed CD; group 2, patients with "potential' CD; group 3, control group, patients without CD. We assessed the standard laboratory data, the level of TG2/DGP and EMA antibodies, as well as the distribution of HLA molecules in the selected patients. Histopathological examination was considered the criterion standard for diagnosis in most cases.The sensitivity of TG2/DGP was 85% and the specificity 92%. EMA showed a sensitivity of 82% and a specificity of 98%. The vast majority of patients diagnosed with CD were either HLA-DQ2.5 (encoded by DQA1*05 & DQB1*02) positive (87.5%) or HLA-DQ8 (encoded by DQB1*03:02) positive (12.5%). One patient showed a positivity only for HLA-DQ2.2 (encoded by DQA1*02 & B1*02).Our study showed that the genetic risk for CD was present in more than one-third of the cases without a confirmed diagnosis of CD. Therefore, the awareness of genetic susceptibility for CD is essential because of the fact that these individuals can develop the disease at any point of their lives. The sensitivity of TG2/DGP and EMA were very similar, whereas EMA presented a higher specificity as that of TG2/DGP.

IgA Antibodies Against Gliadin and Tissue Transglutaminase in Dogs With Chronic Enteritis and Intestinal T-Cell Lymphoma

Molecular clonality analysis of T-cell receptor (TCR) genes for diagnosing T-cell lymphoma is widely used in veterinary medicine. However, differentiating chronic enteritis (CE) from intestinal lymphoma is challenging because of the incompatibility between histopathologic and clonality analysis results. On the basis of findings that canine intestinal T-cell lymphoma and celiac disease share some common features, we conducted serologic examinations in combination with histopathologic and T-cell receptor clonality analyses in 48 dogs diagnosed with either CE or intestinal lymphoma. Immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies against gliadin and tissue transglutaminase (tTG) were quantitatively measured using ELISA. The conditions were classified according to the histopathologic diagnosis, clonality analysis, and combined histopathologic/clonality analysis. Histopathologic analysis showed that dogs with intestinal lymphoma were likely to have high levels of serum IgA antibodies against gliadin and tTG, and serum IgG antibodies against tTG. No correlation between the diagnosed groups and control group was observed in the results of the clonality analysis and histopathologic/clonality analysis. It is interesting that dogs with intestinal lymphoma had a higher serum IgA titer against gliadin and tTG than did dogs with CE. These results suggest an association between repetitive inflammatory stimulation by gliadin peptides and subsequent intestinal lymphoma in dogs.

Lack of evidence of rotavirus-dependent molecular mimicry as a trigger of coeliac disease

New data suggest the involvement of rotavirus (RV) in triggering autoimmunity in coeliac disease (CD) by molecular mimicry between the human-transglutaminase protein and the dodecapeptide (260-271 aa) of the RV protein VP7 (pVP7). To assess the role of RV in the onset of CD, we measured anti-pVP7 antibodies in the sera of children with CD and of control groups. We analysed serum samples of 118 biopsy-proven CD patients and 46 patients with potential CD; 32 children with other gastrointestinal diseases; 107 no-CD children and 107 blood donors. Using enzyme-linked immunosorbent assay (ELISA) assay, we measured immunoglobulin (Ig)A-IgG antibodies against the synthetic peptides pVP7, the human transglutaminase-derived peptide (476-487 aa) which shows a homology with VP7 protein and a control peptide. The triple-layered RV particles (TLPs) containing the VP7 protein and the double-layered RV-particles (DLPs) lacking the VP7 protein were also used as antigens in ELISA assay. Antibody reactivity to the RV-TLPs was positive in 22 of 118 (18%) CD patients and in both paediatric (17 of 107, 16%) and adult (29 of 107, 27%) control groups, without showing a statistically significant difference among them (P = 0·6, P = 0·1). Biopsy-proven CD patients as well as the adult control group demonstrated a high positive antibody reactivity against both pVP7 (34 of 118, 29% CD patients; 66 of 107, 62% adult controls) and control synthetic peptides (35 of 118, 30% CD patients; 56 of 107, 52% adult controls), suggesting a non-specific response against RV pVP7. We show that children with CD do not have higher immune reactivity to RV, thus questioning the molecular mimicry mechanism as a triggering factor of CD.

Herpesvirus Infections and Transglutaminase Type 2 Antibody Positivity in Childhood: The Generation R Study

OBJECTIVES

Persistent viral infections have been implicated in the etiology of autoimmune diseases in adulthood, but it is not known whether herpesviruses are associated with the development of celiac disease autoimmunity in childhood. We assessed whether herpesvirus infections are associated with transglutaminase type 2 antibody (TG2A) concentrations in children at 6 years of age.

METHODS

The present study was embedded within a population-based prospective cohort study. Serum immunoglobulin G levels against Epstein-Barr virus, cytomegalovirus (CMV), and herpes simplex virus type 1 were measured by enzyme-linked immunosorbent assay , and TG2A concentrations with fluorescence enzyme immunoassay in 4420 children at 6 years of age. Children were categorized based on TG2A concentrations into negative (<7 U/mL), positive (≥7-70 U/mL), and strongly positive (≥70 U/mL), that is, 10 times upper limit normal.

RESULTS

Fifty-nine children (1.3%) were TG2A positive, and of these 31 (53%) had concentrations 70 U/mL or more. Children with TG2A concentrations 70 U/mL or more were less often infected with CMV (adjusted odds ratio (aOR) 0.38, 95% CI 0.14-0.98, P = 0.04) and with any of the 3 viruses (aOR 0.38, 95% CI 0.18-0.78, P < 0.01) than children with TG2A negative concentrations. In addition, children with TG2A concentrations 70 U/mL or more were less often infected with 2 or more viruses than children with TG2A negative concentrations (aOR 0.15, 95% CI 0.03-0.65, P = 0.01).

CONCLUSIONS

Both CMV single infection and combined CMV, Epstein-Barr virus and/or herpes simplex virus type 1 infections are inversely associated with strongly TG2A positivity. This may indicate a protective effect of herpesvirus infections in the pathogenesis of celiac disease autoimmunity.

Novel diagnostic techniques for celiac disease

The diagnosis of celiac disease has long been based on the demonstration of gluten-induced small-bowel mucosal damage. However, due to the constantly increasing disease prevalence and limitations in the histology-based criteria there is a pressure towards more serology-based diagnostics. The serological tools are being improved and new non-invasive methods are being developed, but the constantly refined endoscopic and histologic techniques may still prove helpful. Moreover, growing understanding of the disease pathogenesis has led researchers to suggest completely novel approaches to celiac disease diagnostics regardless of disease activity. In this review, we will elucidate the most recent development and possible future innovations in the diagnostic techniques for celiac disease.

Celiac disease can be predicted by high levels of anti-tissue transglutaminase antibodies in population-based screening

OBJECTIVES

The aim of the present study was to evaluate any potential correlation between anti-tissue transglutaminase antibodies of type immunoglobulin A (tTG-IgA) and the degree of gluten-induced enteropathy in children participating in a screening study for celiac disease (CD) and to assess to what extent the revised European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) guidelines cover this group of patients.

METHODS

The present study is a substudy of a cross-sectional CD screening study, Exploring the Iceberg of Celiacs in Sweden, a 2-phased study performed during 2005 to 2006 and 2009 to 2010. The 13,279 participating children had a blood test obtained, and those with positive tTG-IgA were recommended a small intestinal biopsy. The tTG-IgA levels at the time of biopsy were compared with those at the assessment of the biopsy.

RESULTS

There were 267 children included, of whom 230 were diagnosed as having CD. Of all of the children, 67 children had low tTG-IgA levels (<5 U/mL), of whom 55% had Marsh 3 lesions. All of the children with tTG-IgA levels exceeding 10 times the upper limit of normal values of 5 U/mL, that is, 50 U/mL, were diagnosed as having CD. Lowering the cutoff to 3 U/mL, all but 1 child with 30 U/mL got CD diagnosis.

CONCLUSIONS

By adopting the revised ESPGHAN criteria, biopsies could have been omitted in one-fourth of all of the patients. Our results indicate that the criteria may be useful even in screened children. Further studies are needed to confirm whether the 2012 ESPGHAN guidelines should be revised to also apply to the populations being screened.

Evaluation of the ESPGHAN Celiac Guidelines in a North American Pediatric Population

OBJECTIVES

We retrospectively examined the performance of the tissue transglutaminase (TTG), endomysial antibody (EMA) tests, and the ESPGHAN (European Society of Paediatric Gastroenterology, Hepatology and Nutrition) nonbiopsy criteria in a pediatric population.

METHODS

Consecutive celiac serologies and corresponding intestinal biopsy results were obtained on children <18 years old over 3.5 years. Patients were classified into three categories: positive TTG, negative TTG, and IgA deficiency.

RESULTS

Of the 17,505 patients with celiac serology performed, 775 had a positive TTG, 574 with a negative TTG were biopsied, and 25 were IgA deficient. Of the patients with a TTG ≥10 × upper limit of normal (ULN), positive EMA, and symptoms, 98.2% had biopsies consistent with celiac disease (CD). Four human leukocyte antigen (HLA) DQ2/DQ8-positive patients who met the ESPGHAN nonbiopsy criteria did not have CD. In the group with a TTG 3-10 × ULN, 75.7% EMA-positive patients and only 40% EMA-negative patients had CD (P<0.001). Of those with a TTG 1-3 × ULN, 52.2% EMA-positive patients vs. only 13.3% EMA-negative patients had CD (P<0.01). Of the patients with bulbar and duodenal biopsies, 9.8% had CD confined only in the bulb, especially those with a low titer TTG (P<0.01). CD prevalence in our cohort was 34.6%. Sensitivity, specificity, and positive predictive value of the TTG were 98.7%, 86.4%, and 79.4%, respectively.

CONCLUSIONS

The TTG is a very sensitive screen for CD, but positive predictive value improves with a positive EMA titer. To apply the new ESPGHAN guidelines, clinicians must understand the performance of their celiac serology tests.

Screening for celiac disease in the general population and in high-risk groups

BACKGROUND

Celiac disease (CD) occurs in approximately 1% of the Western population. It is a lifelong disorder that is associated with impaired quality of life (QOL) and an excessive risk of comorbidity and death.

OBJECTIVES

To review the literature on screening for CD in relation to the current World Health Organization (WHO) criteria for mass screening.

METHODS

We performed a PubMed search to identify indexed papers on CD screening with a publication date from 1900 until 1 June 2014. When we deemed an abstract relevant, we read the corresponding paper in detail.

RESULTS

CD fulfills several WHO criteria for mass screening (high prevalence, available treatment and difficult clinical detection), but it has not yet been established that treatment of asymptomatic CD may reduce the excessive risk of severe complications, leading to higher QOL nor that it is cost-effective.

CONCLUSIONS

Current evidence is not sufficient to support mass screening for CD, but active case-finding may be appropriate, as we recognize that most patients with CD will still be missed by this strategy. Although proof of benefit is still lacking, screening for CD may be appropriate in high-risk groups.

Serum anti-tissue transglutaminase antibodies detected during febrile illness may not be produced by the intestinal mucosa

Anti-transglutaminase antibodies are the diagnostic marker of celiac disease, and are considered to be synthesized only by intestinal B-lymphocytes. During an infectious disease, these antibodies are transiently detected in serum. We show that these infection-triggered antibodies may not originate in the intestinal mucosa and are not an indication of celiac disease.

Children with celiac disease are more likely to have attended hospital for prior respiratory syncytial virus infection

BACKGROUND AND AIM

The purpose of this study was to examine the association between celiac disease (CD) and prior respiratory syncytial virus (RSV) infection or any viral bronchiolitis.

METHODS

This was a retrospective case-control study. During 2006-2008 small intestinal biopsy data were collected from Sweden's 28 pathology departments. We identified 3,835 children diagnosed with CD (villous atrophy, Marsh stage 3) before the age of 2 years in 1987 or later. Using conditional logistic regression we calculated odds ratios (ORs) for having a prior diagnosis of respiratory syncytial virus or other viral bronchiolitis compared to 19,102 age- and sex-matched controls.

RESULTS

Of the 3,835 children with CD, 36 (0.9 %) had a prior diagnosis of RSV compared to 117/19,102 (0.6 %) matched controls. This corresponded to an OR of 1.46 (95 % CI 1.03-2.07). ORs were similar in girls and boys. The highest ORs were seen in children developing early CD (before 1 year of age (OR 1.82; 95 % CI 0.91-3.62). Prior record of any type of viral bronchiolitis was found in 3.4 % (132/3,835) of individuals with CD and in 2.0 % (390/19,102) of the matched controls corresponding to an OR of 1.60 (95 % CI 1.33-1.92).

CONCLUSIONS

Children with CD diagnosed <2 years of age were more likely to have attended hospital for a prior RSV infection or any viral bronchiolitis than other children.

Celiac disease in adult patients: specific autoantibodies in the diagnosis, monitoring, and screening

The increasing prevalence of celiac disease (CD), especially in adults, its atypical clinical presentation, and the strict, lifelong adherence to gluten-free diet (GFD) as the only option for healthy state create an imperative need for noninvasive methods that can effectively diagnose CD and monitor GFD. Aim. Evaluation of anti-endomysium (EmA) and anti-tissue transglutaminase IgA (tTG-A) antibodies in CD diagnosis, GFD monitoring, and first degree relatives screening in CD adult patients. Methods. 70 newly diagnosed Greek adult patients, 70 controls, and 47 first degree relatives were tested for the presence of EmA and tTG-A. The CD patients were monitored during a 3-year period. Results. EmA predictive ability for CD diagnosis was slightly better compared to tTG-A (P = 0.043). EmA could assess compliance with GFD already from the beginning of the diet, while both EmA and tTG-A had an equal ability to discriminate between strictly and partially compliant patients after the first semester and so on. Screening of first degree relatives resulted in the identification of 2 undiagnosed CD cases. Conclusions. Both EmA and tTG-A are suitable markers in the CD diagnosis, in the screening of CD among first degree relatives, having also an equal performance in the long term monitoring.

Biomarkers for diagnosis and monitoring of celiac disease

Celiac disease (CD) is an autoimmune disorder, which damages the small intestine and is caused by ingestion of gluten in genetically susceptible individuals. The only known effective treatment is a lifelong gluten-free diet. Genetic risk factors have been identified and nearly all patients are HLA-DQ2 and/or HLA-DQ8 positive. Specific autoantibodies, IgA antitissue transglutaminase-2, antiendomysium, and antideaminated forms of gliadin peptide antibodies, are widely used as diagnostic aids in celiac patients. However, the discovery of new biomarkers may help in the diagnosis and follow-up of the disease. Recently, the molecule REG Iα, involved in tissue regeneration, has been proposed as a new biomarker of CD. REG Iα expression is increased in the target tissue and in the sera of celiac patients during damage and inflammation, decreasing after gluten-free diet. In this article we review the main biomarkers for diagnosis and monitoring of CD, focusing on the immune response-related mechanisms.

Celiac disease: the new proposed ESPGHAN diagnostic criteria do work well in a selected population

BACKGROUND

The need for an early and accurate diagnosis in celiac disease (CD) has focused attention on new diagnostic approaches, based on the efficiency of serological markers and the high negative predictive value of human leukocyte antigen (HLA) non-DQ2/8.

METHODS

We performed a retrospective review of all of the patients suspected of having CD who had undergone a small bowel biopsy in our gastroenterology unit. All symptomatic children with serological marker at time of biopsy (immunoglobulin A-tissue transglutaminase antibody, endomysial antibody, and HLA genotype) were included. The triple test (TT) was positive if immunoglobulin A-tissue transglutaminase antibody was 10 times the upper limit of normal, plus positive endomysial antibody plus human leukocyte antigen-DQ2/DQ8.

RESULTS

A total of 150 patients met the inclusion criteria and were enrolled in the study. One hundred sixteen were positive for the TT; 113 of 116 (97.4%) had a Marsh 2/3 histological lesion and had been considered to have CD. Thus, positive predictive value of the TT was 97.4%. The other 3 cases (2.6%) had Marsh 0/1 lesion, so we consider them to be false-positives for the TT; however, on follow-up, all 3 children developed histological damage after a gluten challenge. Finally, the positive predictive value of the TT was 100%. Thirty-four patients were negative for the TT: 22 patients are celiac, 3 are celiac but challenge gluten diet is pending, and the 9 patients left have other gastrointestinal disorder.

CONCLUSIONS

Our study supports the view that in selected children who are symptomatic and positive for the TT, CD diagnosis could be established independent of histological findings.

Binding of autoantibodies to the core region of tissue transglutaminase is a feature of paediatric coeliac disease

OBJECTIVES

Production of autoantibodies to the enzyme tissue transglutaminase (tTG) is a hallmark of coeliac disease (CD). We have previously demonstrated that the immumoglobulin (Ig) A response to tTG in adult CD specifically targets its catalytic core region, containing the active-site triad of amino acids. The aim of the present study was to investigate this phenomenon in paediatric patients with CD, and to elucidate the contribution of each active-site residue to epitopes recognised. The specificity of the IgG anti-tTG response was also investigated and compared with that of the IgA anti-tTG response, in both paediatric and adult patients with CD.

METHODS

Wild-type and novel variants of tTG were generated via site-directed mutagenesis and expressed as glutathione-S-transferase-fusion proteins in Escherichia coli BL-21. The mutagenic variants of tTG had substitutions of 1, 1, or all of the 3 of the catalytic triad amino acids. All of the recombinant tTGs were tested for their antigenicity in IgA and IgG enzyme-linked immunosorbent assays with cohorts of paediatric (n=63) and adult (n=30) CD sera.

RESULTS

Substitution of even 1 amino acid in the catalytic triad resulted in a significant reduction of CD IgA and IgG anti-tTG binding, with all of the mutant proteins displaying diminished antigenicity compared with the wild-type protein.

CONCLUSIONS

The core region of tTG is specifically targeted from early on in disease course by CD patient autoantibodies of both the IgA and IgG class.

Type 1 diabetes associated and tissue transglutaminase autoantibodies in patients without type 1 diabetes and coeliac disease with confirmed viral infections

Coeliac disease and type 1 diabetes are autoimmune diseases that may share the same initiating environmental factors. In this study, the occurrence of type 1 diabetes associated autoantibodies (GADA and IA-2A) and tissue transglutaminase autoantibodies (TGA) was determined in patients with confirmed viral infections and no signs of type 1 diabetes or coeliac disease. Serum samples from 82 Cuban patients tested positive for PCR and IgG specific to enterovirus (HEV, serotype echovirus 16, 20 samples), Epstein-Barr virus (EBV, 20 samples), cytomegalovirus (CMV, 21 samples), and hepatitis C virus (HCV, 21 samples); and sera from 164 controls negative serologically to EBV, CMV, HCV, and echovirus 16 were enrolled in the study. All subjects were screened for GADA, IA-2A, and TGA. The prevalence of TGA in patients infected with HEV, EBV, CMV, or HCV was 55% (11/20), 25% (5/20), 9.5% (2/21), and 9.5% (2/21), respectively. GADA and IA-2A were found in 15% (3/20) and 25% (5/20) of patients infected with HEV. None of the patients infected by EBV, CMV, and HCV had GADA or IA-2A. All children infected with HEV who were positive for type 1 diabetes-associated autoantibodies were also TGA-positive. None of the sera from uninfected subjects were positive for GADA, IA-2A or TGA. In conclusion, TGA can develop during infection with HEV, EBV, CMV, or HCV, while the emergence of islet cell related autoantibodies is restricted to HEV infections. The findings suggest that HEV may be a shared environmental factor for the development of islet and gut-related autoimmunity.

Celiac disease in children and adolescents: special considerations

Although there are many commonalities between adult and pediatric celiac disease (CD), special considerations must be taken into account when working with children and adolescents. In this patient population, there are unique aspects of the epidemiology, pathogenesis, presentation, diagnosis, and management of CD. In terms of management, early and timely recognition of CD can maximize childhood and adolescent development and prevent complications. This requires insight into the unique presentations of CD in the pediatric population. Furthermore, health care providers must use proper screening methods and continue surveillance of at-risk individuals throughout childhood. Potential interventions for primary prevention of CD in children, although not completely understood, may offer some benefit. The goals of this article are to discuss in detail these special considerations when dealing with pediatric CD.

In vitro models for gluten toxicity: relevance for celiac disease pathogenesis and development of novel treatment options

In genetically predisposed individuals, dietary gluten in wheat, rye and barley triggers celiac disease, a systemic autoimmune disorder hallmarked by an extensive small-bowel mucosal immune response. The current conception of celiac disease pathogenesis is that it involves components of both innate and adaptive immunity whose activation typically leads to small-bowel villous atrophy with crypt hyperplasia. Currently, the only effective treatment for celiac disease is a strict lifelong gluten-free diet excluding all wheat-, rye- and barley-containing food products. During the diet, the clinical symptoms improve and the small-bowel mucosal damage recovers, while re-introduction of gluten into the diet leads to re-appearance of the symptoms and deterioration of the small-bowel mucosal architecture. In view of the restricted nature of the diet, alternative treatment is warranted. Improved understanding of the molecular basis of celiac disease has enabled researchers to suggest other therapeutic approaches. Although there is no animal model reproducing all features of celiac disease, the use of in vitro approaches including a variety of cell lines and the celiac patient small-bowel mucosal biopsy organ culture has generated knowledge about pathogenesis of celiac disease. In these culture systems, gluten induces different effects that can be quantified, thus also enabling studies concerning the efficacy of candidate therapeutic compounds for celiac disease. This review describes the intestinal epithelial cell models, celiac patient T-cell lines and clones, as well as the small-bowel mucosal organ culture methods widely used in studies of celiac disease, and summarizes the major findings obtained with these systems.

European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease

OBJECTIVE

Diagnostic criteria for coeliac disease (CD) from the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) were published in 1990. Since then, the autoantigen in CD, tissue transglutaminase, has been identified; the perception of CD has changed from that of a rather uncommon enteropathy to a common multiorgan disease strongly dependent on the haplotypes human leukocyte antigen (HLA)-DQ2 and HLA-DQ8; and CD-specific antibody tests have improved.

METHODS

A panel of 17 experts defined CD and developed new diagnostic criteria based on the Delphi process. Two groups of patients were defined with different diagnostic approaches to diagnose CD: children with symptoms suggestive of CD (group 1) and asymptomatic children at increased risk for CD (group 2). The 2004 National Institutes of Health/Agency for Healthcare Research and Quality report and a systematic literature search on antibody tests for CD in paediatric patients covering the years 2004 to 2009 was the basis for the evidence-based recommendations on CD-specific antibody testing.

RESULTS

In group 1, the diagnosis of CD is based on symptoms, positive serology, and histology that is consistent with CD. If immunoglobulin A anti-tissue transglutaminase type 2 antibody titers are high (>10 times the upper limit of normal), then the option is to diagnose CD without duodenal biopsies by applying a strict protocol with further laboratory tests. In group 2, the diagnosis of CD is based on positive serology and histology. HLA-DQ2 and HLA-DQ8 testing is valuable because CD is unlikely if both haplotypes are negative.

CONCLUSIONS

The aim of the new guidelines was to achieve a high diagnostic accuracy and to reduce the burden for patients and their families. The performance of these guidelines in clinical practice should be evaluated prospectively.

Celiac disease diagnosis and management: a 46-year-old woman with anemia

Celiac disease is one of the most prevalent autoimmune gastrointestinal disorders, but as the case of Ms J illustrates, diagnosis is often delayed or missed. Based on serologic studies, the prevalence of celiac disease in many populations is estimated to be approximately 1% and has been increasing steadily over the last 50 years. Evaluation for celiac disease is generally straightforward and uses commonly available serologic tests; however, the signs and symptoms of celiac disease are nonspecific and highly heterogeneous, making diagnosis difficult. Although celiac disease is often considered a mild disorder treatable with simple dietary changes, in reality celiac disease imparts considerable risks, including reduced bone mineral density, impaired quality of life, and increased overall mortality. In addition, a gluten-free diet is highly burdensome and can profoundly affect patients and their families. For these reasons, care of individuals with celiac disease requires prompt diagnosis and ongoing multidisciplinary management.

Regenerating gene Iα is a biomarker for diagnosis and monitoring of celiac disease: a preliminary study

The regenerating gene (REG) is a multigene family in humans that plays a role in tissue regeneration. The REG Iα protein is expressed in the pancreas and the gastrointestinal tract and is involved in the pathophysiology of gastritis, pancreatitis, cancer, inflammatory bowel disease, and type 1 diabetes (T1D). Celiac disease (CD) is an autoimmune disease caused by the ingestion of gluten in genetically susceptible individuals. Our aim was to determine whether the serum REG Iα concentration reflects the destructive/regenerative process in the small bowel in CD. REG Iα was determined by enzyme-linked immunosorbent assay (ELISA) in 40 patients with active CD, and in 19 of them, REG Iα was assessed after following a gluten free diet. As controls, 35 healthy subjects were included in the study. Autoantibodies to transglutaminase, gliadin, and endomisium were measured also. We found a significant increase in REG Iα in the sera of CD patients when compared with controls. REG Iα levels decreased after a gluten-free diet together with a significant reduction in antitransglutaminase antibodies. T1D and pernicious anemia patients displayed normal serum REG Iα concentrations. This preliminary study suggests that REG Iα protein levels can be used as a biomarker for the diagnosis and monitoring of CD.

Prevention measures and exploratory pharmacological treatments of celiac disease

Increasing prevalence, protean clinical manifestations, and lack of pharmacological therapy make celiac disease (CD) a complex and highly relevant illness in gastroenterology. This chronic inflammatory disorder of the small intestine is caused by the ingestion of gluten containing cereals in genetically susceptible individuals, leading to a variety of gastrointestinal (GI) and non-GI manifestations. Awareness among physicians is growing due to accessible and highly accurate diagnostic and screening methods. Recent evidence suggests a possible rising incidence of CD. Environmental factors such as early life gluten exposure, intestinal infections, short duration of breast-feeding, and changes in intestinal microbiota have been proposed to have a role in CD pathogenesis. Thus, prevention approaches to diminish the rising prevalence of CD are currently being evaluated. Still, the cornerstone treatment of CD remains a strict gluten-free diet. This nutritional regime is demanding, and non-adherence is common because of social isolation, financial issues, or restriction of food diversity. Allowing patients to occasionally consume small amounts of gluten would greatly improve their quality of life. Owing to recent advances in the understanding of the pathogenesis of CD, different targets have been identified and have motivated the development of several experimental therapeutic strategies. The main goal of this review is to discuss the mechanisms that can be exploited therapeutically to prevent or delay CD, disease associations and its complications. Current treatments for complications of CD, including refractory CD and malignancy, are beyond the scope of this review.

Natural history of celiac disease autoimmunity in a USA cohort followed since 1974

BACKGROUND

The natural history and the possible changes of celiac disease (CD) prevalence over time are still unclear.

OBJECTIVES

1) To establish whether loss of tolerance to gluten may occur at any age; 2) to investigate possible changes of CD prevalence over time; and 3) to investigate CD-related co-morbidities.

METHODS

We analyzed 3,511 subjects with matched samples from 1974 (CLUE I) and 1989 (CLUE II). To avoid a selection bias regarding survival, we also screened 840 CLUE I participants who deceased after the 1974 survey. Outcome measure. CD autoimmunity (positivity to auto-antibodies) over time.

RESULTS

CD autoimmunity was detected in seven subjects in 1974 (prevalence 1:501) and in an additional nine subjects in 1989 (prevalence 1:219). Two cases of CD autoimmunity were found among the 840 subjects deceased after CLUE I. Compared to controls, untreated CD subjects showed increased incidence of osteoporosis and associated autoimmune disorders, but they did not reach statistical significance.

CONCLUSIONS

During a 15-year period CD prevalence increased 2-fold in the CLUE cohort and 5-fold overall in the US since 1974. The CLUE study demonstrated that this increase was due to an increasing number of subjects that lost the immunological tolerance to gluten in their adulthood.

Markers of gluten sensitivity and celiac disease in recent-onset psychosis and multi-episode schizophrenia

BACKGROUND

Increased immune sensitivity to gluten has been reported in schizophrenia. However, studies are inconsistent about this association.

METHODS

The sample of 471 individuals included 129 with recent-onset psychosis, 191 with multi-episode schizophrenia, and 151 controls. Immunoglobulin (Ig)G and IgA antibodies to gliadin and to tissue transglutaminase, and IgG antibodies to deamidated gliadin were measured. Quantitative levels of antibodies in the psychiatric groups were compared with controls. All participants were categorized as to whether their levels of antibodies met standardized cutoffs for celiac disease. HLA DQ2 and HLA DQ8 alleles were detected by real-time polymerase chain reaction.

RESULTS

Individuals with recent-onset psychosis had increased levels of IgG (odds ratio [OR] 5.50; 95% confidence interval [CI] 2.65-11.42) and IgA (OR 2.75; 95% CI 1.31-5.75) antibodies to gliadin compared with control subjects. Individuals with multi-episode schizophrenia also had significantly increased levels of IgG antibodies to gliadin (OR 6.19; 95% CI 2.70-14.16). IgG antibodies to deamidated gliadin and IgA antibodies to tissue transglutaminase were not elevated in either psychiatric group, and fewer than 1% of individuals in each of the groups had levels of these antibodies predictive of celiac disease. There were no significant differences in the distribution of the HLA DQ2/8 alleles among the groups.

CONCLUSIONS

Individuals with recent-onset psychosis and with multi-episode schizophrenia who have increased antibodies to gliadin may share some immunologic features of celiac disease, but their immune response to gliadin differs from that of celiac disease.