Strongly positive tissue transglutaminase antibodies are associated with Marsh 3 histopathology in adult and pediatric celiac disease

The strategic use of biopsy in the diagnosis of coeliac disease in adults

BACKGROUND

The paediatric guidelines support the use of the 'No Biopsy Approach' in the diagnosis of coeliac disease (CD). We aimed to determine the correlation between anti tissue transglutaminase (anti-TTG serology) ≥10 times the upper limit of normal (ULN), using the Celikey ® ELiA assay and histological findings. Our secondary aim was to determine the safety of this approach in our centre.

METHODS

A retrospective analysis of adult patients referred to a tertiary referral centre with raised anti-TTG titres and/or histological changes of coeliac on D2 biopsies between 2014 - 2019. Excluded patients were those who did not have a biopsy performed, or whose biopsy was unavailable for review, selective IgA deficiency, and gluten elimination prior to biopsy. Biopsies were classified according to Marsh, by two independent pathologists, blinded to the anti-TTG titre.

RESULTS

164 patients had positive anti-TTG serology and duodenal biopsy in our centre prior to starting a gluten free diet (GFD) in the period 2014 - 2019. Of these 164 patients (median age 40yrs, 62% female), 68 (33%) had an anti-TTG titre ≥10 x ULN, 99% of which had a Marsh grading ≥ 3 and 1% had a Marsh of 2 on biopsy. 91% had either a normal index gastroscopy or findings of mild gastritis/oesophagitis.

CONCLUSIONS

We found a 98.5% positive predictive value (PPV) of determining CD (i.e., Marsh ≥ 3) in those with an anti-TTG ≥10 x ULN. In those with moderate to high-risk clinical suspicion of CD we propose that duodenal biopsy is unnecessary for diagnosis.

Serum anti-tissue transglutaminase IgA and prediction of duodenal villous atrophy in adults with suspected coeliac disease without IgA deficiency (Bi.A.CeD): a multicentre, prospective cohort study

BACKGROUND

Whether coeliac disease in adults can be diagnosed with serology alone remains controversial. We aimed to evaluate the accuracy of serum anti-tissue transglutaminase IgA (tTG-IgA) in the diagnosis of coeliac disease.

METHODS

In this multicentre, prospective cohort study, adult participants (aged ≥18 years) with suspected coeliac disease without IgA deficiency who were not on a gluten-free diet and who had a local serum tTG-IgA measurement, were enrolled from Feb 27, 2018, to Dec 24, 2020, by 14 tertiary referral centres (ten from Europe, two from Asia, one from Oceania, and one from South America) to undergo local endoscopic duodenal biopsy. Local serum tTG-IgA was measured with 14 different test brands and concentration expressed as a multiple of each test's upper limit of normal (ULN), and defined as positive when greater than 1 times the ULN. The main study outcome was the reliability of serum tests for the diagnosis of coeliac disease, as defined by duodenal villous atrophy (Marsh type 3 or Corazza-Villanacci grade B). Histology was evaluated by the local pathologist, with discordant cases (positive tTG-IgA without duodenal villous atrophy or negative tTG-IgA with duodenal villous atrophy) re-evaluated by a central pathologist. The reliability of serum tests for the prediction of duodenal villous atrophy was evaluated according to sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve (AUC) for categorical and continuous data.

FINDINGS

We enrolled 436 participants with complete local data on serum tTG-IgA and duodenal histology (296 [68%] women and 140 [32%] men; mean age 40 years [SD 15]). Positive serum tTG-IgA was detected in 363 (83%) participants and negative serum tTG-IgA in 73 (17%). Of the 363 participants with positive serum tTG-IgA, 341 had positive histology (true positives) and 22 had negative histology (false positives) after local review. Of the 73 participants with negative serum tTG-IgA, seven had positive histology (false negatives) and 66 had negative histology (true negatives) after local review. The positive predictive value was 93·9% (95% CI 89·2-98·6), the negative predictive value was 90·4% (85·5-95·3), sensitivity was 98·0% (95·3-100·0), and specificity was 75·0% (66·6-83·4). After central re-evaluation of duodenal histology in 29 discordant cases, there were 348 true positive cases, 15 false positive cases, 66 true negative cases, and seven false negative cases, resulting in a positive predictive value of 95·9% (92·0-99·8), a negative predictive value of 90·4% (85·5-95·3), a sensitivity of 98·0% (95·3-100·0), and a specificity of 81·5% (73·9-89·1). Either using the local or central definition of duodenal histology, the positive predictive value of local serum tTG-IgA increased when the serological threshold was defined at increasing multiples of the ULN (p<0·0001). The AUC for serum tTG-IgA for the prediction of duodenal villous atrophy was 0·87 (95% CI 0·81-0·92) when applying the categorical definition of serum tTG-IgA (positive [>1 × ULN] vs negative [≤1 × ULN]), and 0·93 (0·89-0·96) when applying the numerical definition of serum tTG-IgA (multiples of the ULN). Additional endoscopic findings included peptic gastritis (nine patients), autoimmune atrophic gastritis (three), reflux oesophagitis (31), gastric or duodenal ulcer (three), and Barrett's oesophagus (one). In the 1-year follow-up, a midgut ileum lymphoma was diagnosed in a woman on a gluten-free diet.

INTERPRETATION

Our data showed that biopsy could be reasonably avoided in the diagnosis of coeliac disease in adults with reliable suspicion of coeliac disease and high serum tTG-IgA.

FUNDING

None.

Comparison of Clinical, Biochemical and Histological Features between Adult Celiac Patients with High and Low Anti-Transglutaminase IgA Titer at Diagnosis and Follow-Up

In adults, celiac disease (CD) diagnosis is based on specific serology (anti-transglutaminase IgA-anti-tTG) and duodenal histology. Evidence is raising the possibility of perform CD diagnosis based only on high anti-tTG titer in children. We aimed to evaluate clinical, histological and biochemical differences between adult patients with high tTG IgA titer (HT) and those with low titer (LT) at CD diagnosis and follow-up. This retrospective study included consecutive adult CD patients divided into two groups: HT (anti-tTG > 10 × ULN) and LT (anti-tTG < 10 × ULN). Clinical, biochemical and histological features were compared between groups at CD diagnosis and at follow-up. A total of 291 patients were included (HT: 47.1%; LT: 52.9%). At CD diagnosis, HT patients showed a non 'classical' presentation (p = 0.04), Marsh 3C (p = 0.005), hypoferritinaemia (p = 0.006) and osteopenia/osteoporosis (p = 0.04) more frequently than LT patients. A total of 216 patients (HT: 48.6%; LT: 51.4%) performed a follow-up after a median Gluten-free diet of 14 months; HT patients had persistent antibodies positivity (p = 0.001) more frequently and GI symptoms (p = 0.04) less frequently than LT patients. In conclusion, HT patients presented severe histological damage more frequently at diagnosis, recovering similarly to LT patients after the start of the Gluten-free diet. At follow-up, anti-tTG persisted positive in HT more frequently compared to LT patients, without differences regarding histological recovery and clinical improvement.

Correlation of Anti-Tissue Transglutaminase Antibodies With the Mucosal Changes and IgA Status of Children With Celiac Disease

OBJECTIVES

The objective of this study was to assess the association between serological markers and changes of the intestinal mucosa in children with celiac disease (CD).

METHODS

Clinical data from CD patients under 15 years old were collected from the participating centers in an on-line multicenter nationwide observational Spanish registry called REPAC-2 (2011-2017). Correlation between anti-tissue transglutaminase antibodies (t-TGA) levels and other variables, including mucosal damage and clinical findings (symptoms, age, and gender), was assessed.

RESULTS

A total of 2955 of 4838 patients had t-TGA and a small bowel biopsy (SBB) performed for CD diagnosis. A total of 1931 (66.2%) patients with normal IgA values had a Marsh 3b-c lesion and 1892 (64.9%) had t-TGA Immunoglobulin A (IgA) ≥ 10 times upper limit of normal (ULN). There is a statistically significant association between t-TGA IgA levels and the degree of mucosal damage ( P < 0.001), the higher the t-TGA IgA levels the more severe the mucosal damage. Those patients who reported symptoms had more severe mucosal damage ( P = 0.001). On the contrary, there was a negative association between age and changes of the intestinal mucosa ( P < 0.001). No association was found with gender. Regarding the IgA-deficient patients, 47.4% (18 cases) had t-TGA Immunoglobulin A (IgA) ≥ 10 times ULN and a Marsh 3b-c lesion was observed in 68.4% (26 patients). No statistical relation was found between t-TGA IgG levels and the changes of the intestinal mucosa, neither a relation with age, gender, or symptoms.

CONCLUSIONS

There is a positive correlation between t-TGA IgA levels and the severity of changes of the intestinal mucosa. Such correlation was not found in IgA-deficient patients who had positive t-TGA IgG serology. The results in this group of patients support the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition recommendations about the need of performing a SBB in IgA-deficient individuals despite high t-TGA IgG levels.

Diet and Vitiligo: The Story So Far

Vitiligo is an acquired skin pigmentation disease with a global burden of 0.5 to 2 percent of the population. Vitiligo therapy frequently poses a difficulty, which has sparked interest in alternative treatment modalities, including multivitamins and herbal supplementation. It has previously been established that nutrition plays a crucial role in developing, amplifying, or rehabilitating an array of human disorders. However, the correlation between diet diversity and immune-mediated skin diseases is still up to interpretation. Several supplements have been studied, including vitamins, minerals, and herbal supplements. Most studies agree that combining vitamin B12, folic acid, and sun exposure is good for inducing repigmentation. Supplementation of zinc and phenylalanine when used in conjunction with topical steroids or UV-B (ultraviolet B) treatment shows therapeutic effects on vitiligo due to their role in the melanin synthesis pathway. Investigations conducted on herbal supplements have revealed that most of them contain antioxidants, which aid in repigmentation. This narrative review's purpose is to discuss nutrition's function in immune-mediated inflammatory skin diseases from the perspective of the most recent and reliable information available. 

The ever -present need for biopsy to diagnose coeliac disease safely

Coeliac disease (CD) is an autoimmune enteropathy which occurs in genetically predisposed individuals on exposure to gluten. The recommended diagnostic approach includes serological screening by Anti-tissue Transglutaminase antibody (anti-tTG) followed by a small intestinal biopsy. As high anti-tTG antibody is expected to be significantly associated with MARSH III histopathological changes in the small intestine, it has now become the basis for a biopsy-free approach to diagnose CD. However, we report cases of giardiasis mimicking CD both clinically and serologically; differentiation demands small intestinal biopsy.

The seroprevalence of celiac disease in patients with symptoms of irritable bowel syndrome: A cross-sectional study in north of Iran

BACKGROUND

Celiac disease (CD) is a common cause of malabsorption that is definitively diagnosed by abnormal bowel biopsy, symptoms and histologic changes to gluten free diet. The symptoms of irritable bowel syndrome (IBS) are common in our community as the majority of people in Guilan, north of Iran, consume rice daily. Also, a number of celiac patients are unknown, and IBS are mistakenly diagnosed.

OBJECTIVE

This study aimed to evaluate the prevalence of CD among IBS patients.

METHODS

A total of 475 consecutive patients with IBS, confirmed by Rome IV, underwent celiac serological tests antitissue transglutaminase antibodies (IgA-tTG, IgG-tTG) after obtaining a written consent form. In case of positive serological tests, biopsy was performed from small intestine after endoscopyRESULTS: Thirty-one (6.53%, 95% CI: 4.55-9.22) patients were positive for celiac serology. Based on Marsh-Oberhuber criteria, out of 9 patients with positive pathology 77.78% (95% CI: 40.19-96.05) had marsh IIIc. In IBS patients cramp (0.009) and stomach fullness (0.021) were two statistically significant IBS symptoms.

CONCLUSIONS

We suggest physicians to consider celiac examinations for all patients with IBS symptoms, even for patients with no obvious celiac symptoms.

Antitissue transglutaminase antibodies' normalization after starting a gluten-free diet in a large population of celiac children-a real-life experience

INTRODUCTION

Few data are available regarding the trend of IgA anti-transglutaminase antibodies (TGA-IgA) in children with celiac disease (CD) on a gluten-free diet (GFD). Our aim is to examine the normalization time of CD serology in a large pediatric population, and its predictors.

MATERIAL AND METHODS

We retrospectively evaluated the normalization time of TGA-IgA and its predictive factors (age, sex, ethnicity, symptoms, associated diabetes/thyroiditis, Marsh stage, TGA-IgA and endomysial antibody levels at diagnosis, diet adherence), in 1024 children diagnosed from 2000 to 2019 in three pediatric Italian centers, on a GFD.

RESULTS

TGA-IgA remission was reached in 67,3%, 80,7%, 89,8% and 94,9% after 12, 18, 24 and 36 months from starting a GFD, respectively (median time = 9 months). TGA-IgA >10´upper limit of normal at diagnosis (HR = 0.56), age 7-12 years old (HR = 0.83), poor compliance to diet (HR = 0.69), female sex (HR = 0.82), non-Caucasian ethnicity (HR = 0.75), and comorbidities (HR = 0.72) were independent factors significantly associated with longer time to normalization.

CONCLUSIONS

Our population is the largest in the literature, with the majority of patients normalizing CD serology within 24 months from starting a GFD. We suggest a special attention to patients with comorbidities, language barriers or age 7-12 years for a proper management and follow-up.

A new double immunohistochemistry method to detect mucosal anti-transglutaminase IgA deposits in coeliac children

BACKGROUND

Intestinal transglutaminase (TG2) IgA deposits represent early marker of coeliac disease (CeD) and can predict the evolution towards intestinal atrophy.

AIMS

To validate a double immunohistochemistry method for the determination of intestinal TG2 IgA deposits on formalin-fixed paraffin-embedded biopsies.

METHODS

Immunohistochemistry was tested on: 1) children with overt CeD [persistently positive serum IgA anti-tissue transglutaminase type 2 (TGA-IgA) with moderate or low titer, and histological findings of CeD]; 2) potential CeD (persistently positive serum TGA-IgA and normal intestinal mucosa) and 3) controls (negative serum TGA-IgA and normal intestinal mucosa).

RESULTS

Samples from 61 children were analyzed (32 overt CeD, 14 potential CeD, and 15 controls). Deposits appeared as focal, multifocal, or confluent extracellular foci of red and brown staining colocalization in the sub-epithelium and around mucosal vessels. Deposits were present in all 32 children with overt CeD and in 9/14 potential CeD. Deposits were never observed in the 15 controls. Patients with higher serum level of TGA-IgA and with mucosal atrophy showed mostly a multifocal/diffuse pattern of deposits distribution. The bulb appeared most severely involved. In potential CeD deposits showed mainly a focal distribution.

CONCLUSION

Our results indicate double immunohistochemistry as promising diagnostic tool to improve diagnosis of CeD.

Association between celiac disease and vitiligo: A review of the literature

Celiac disease (CD) is an autoimmune intestinal disease caused by the intake of gluten-containing cereals and their products by individuals with genetic susceptibility genes. Vitiligo is a commonly acquired depigmentation of the skin; its clinical manifestation are skin patches caused by localized or generalized melanin deficiency. Both diseases have similar global incidence rates (approximately 1%) and are associated to similar diseases, including autoimmune bullous disease, inflammatory bowel disease, autoimmune thyroiditis, autoimmune gastritis, and type 1 diabetes. The relationship between CD and vitiligo has been reported in several studies, but their conclusions are inconsistent. Further, it has also been reported that a gluten-free diet (GFD) can improve the symptoms of immune-related skin diseases such as vitiligo. In this mini-review, we summarize and review the literature on the relationship between CD and vitiligo, assess the therapeutic significance of GFD for patients with vitiligo, and explore their possible physiopathology. We are hopeful that the information summarized here will assist physicians who treat patients with CD or vitiligo, thereby improving the prognosis.

Prospective study using villous length morphometry as an adjunctive tool to assess modified Marsh grade in patients with coeliac disease

Coeliac disease, an autoimmune disease, is caused by ingestion of gluten in genetically susceptible individuals. The currently used modified-Marsh grading, used to assess mucosal injury, is fraught with interobserver and intraobserver variability. The aim is to reduce this variability by villous length morphometry. Our prospective study was conducted on newly diagnosed cases of coeliac disease that were assessed by serohaematological profile, and duodenal biopsies were evaluated by modified Marsh grading. Villous length was measured in Grades 2, 3a and 3b using an eyepiece graticule lens calibrated with a stage micrometer. Severity of mucosal injury in different Marsh grades was significantly correlated to mean villous length, elevation of mean IgA tTG and drop in haemoglobin.

Distinctive Microbial Signatures and Gut-Brain Crosstalk in Pediatric Patients with Coeliac Disease and Type 1 Diabetes Mellitus

Coeliac disease (CD) and Type 1 diabetes mellitus (T1DM) are immune-mediated diseases. Emerging evidence suggests that dysbiosis in the gut microbiome plays a role in the pathogenesis of both diseases and may also be associated with the development of neuropathy. The primary goal in this cross-sectional pilot study was to identify whether there are distinct gut microbiota alterations in children with CD (n = 19), T1DM (n = 18) and both CD and T1DM (n = 9) compared to healthy controls (n = 12). Our second goal was to explore the relationship between neuropathy (corneal nerve fiber damage) and the gut microbiome composition. Microbiota composition was determined by 16S rRNA gene sequencing. Corneal confocal microscopy was used to determine nerve fiber damage. There was a significant difference in the overall microbial diversity between the four groups with healthy controls having a greater microbial diversity as compared to the patients. The abundance of pathogenic proteobacteria Shigella and E. coli were significantly higher in CD patients. Differential abundance analysis showed that several bacterial amplicon sequence variants (ASVs) distinguished CD from T1DM. The tissue transglutaminase antibody correlated significantly with a decrease in gut microbial diversity. Furthermore, the Bacteroidetes phylum, specifically the genus Parabacteroides was significantly correlated with corneal nerve fiber loss in the subjects with neuropathic damage belonging to the diseased groups. We conclude that disease-specific gut microbial features traceable down to the ASV level distinguish children with CD from T1DM and specific gut microbial signatures may be associated with small fiber neuropathy. Further research on the mechanisms linking altered microbial diversity with neuropathy are warranted.

Anti-tissue transglutaminase titers are associated with endoscopic findings and severity of mucosal damage in children with celiac disease

We aimed to assess the correlation between clinical findings, serology, endoscopic findings, and histology in children diagnosed with celiac disease. Medical records of children diagnosed with celiac disease (2010-2017) at the Schneider Children's Hospital were reviewed retrospectively. Correlation between serologic measures anti-tissue transglutaminase (anti-tTG)/anti-endomysial antibodies (EMA) and other variables including mucosal damage, endoscopic findings (scalloping of duodenal folds), and clinical findings (abdominal pain, diarrhea, and anemia) was assessed. Out of 686 patients, 432 patients fulfilled the inclusion criteria (females 262, 61%; median age 6.0; interquartile range 4.0-9.0 years). Distribution of histopathology findings was Marsh IIIa 4%, Marsh IIIb 25%, and Marsh IIIc 71% with 313 (73%) patients having anti-tTG titer of ≥ 10 times the upper normal limit. Anti-tTG titer (but not EMA) positively correlated with Marsh grades, scalloping of duodenal folds and anemia. Anti-tTG ≥ 10 times the upper normal limit was associated with Marsh IIIc changes with an adjusted odds ratio of 4.5 (95% confidence interval, 1.7-12.1). Diarrhea and abdominal pain were not associated with serologic, endoscopic, or histologic markers of disease severity.Conclusion: Anti-tTG titers correlated with macroscopic and microscopic mucosal damage, with anemia but not with diarrhea or abdominal pain in children with celiac disease. What is Known: • Tissue transglutaminase antibody titers were shown to correlate with the degree of mucosal damage in patients with celiac disease. • There is a limited evidence regarding the association of celiac serologies with endoscopic and clinical measures. What is New: • Higher titers of tissue transglutaminase but not anti-endomysial antibodies are associated with more severe histologic and endoscopic damage and with the presence of anemia. • Symptoms do not correlate with the severity of mucosal damage such as scalloping of duodenal folds and histopathology changes according to Marsh classification or with serologic markers.

Value of biopsy in a cohort of children with high-titer celiac serologies: observation of dynamic policy differences between Europe and North America

Background

Healthcare systems implement change at different rates because of differences in incentives, organizational processes, key influencers, and management styles. A comparable set of forces may play out at the national and international levels as demonstrated in significant differences in the diagnostic management of pediatric Celiac Disease (CD) between European and North American practitioners.

Methods

We use retrospective clinical cohorts of 27,868 serum tissue transglutaminase (tTG) immunoglobulin A levels and 7907 upper gastrointestinal endoscopy pathology reports to create a dataset of 793 pathology reports with matching tTG results between July 1 of 2014 and July 1 of 2018. We use this dataset to characterize histopathological findings in the duodenum, stomach and esophagus of patients as a function of serum tTG levels. In addition, we use the dataset to estimate the local and national cost of endoscopies performed in patients with serum tTG levels greater than 10 times the upper limit of normal.

Results

Using evidence from a US tertiary care center, we show that in the cohort of pediatric patients with high pre-test probability of CD as determined by serum tTG levels, biopsy provides no additional diagnostic value for CD, and that it counter-intuitively introduces diagnostic uncertainty in a number of patients. We estimate that using the European diagnostic algorithms could avoid between 4891 and 7738 pediatric endoscopies per year in the US for evaluation of CD.

Conclusions

This study considers the North American and European management guidelines for the diagnosis of pediatric CD and highlights the slow adoption in North America of evidence-based algorithms developed and applied in Europe for triage of endoscopy and biopsy. We suggest that system dynamics influences that help maintain the status quo in North America include a variety of social and economic factors in addition to medical evidence. This work contributes to the growing body of evidence that the dynamics that largely favor maintaining status quo management policies in a variety of systems extend to clinical medicine and potentially influence clinical decisions at the level of individual patients and the population.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12913-020-05815-0.

European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for Diagnosing Coeliac Disease 2020

OBJECTIVES

The ESPGHAN 2012 coeliac disease (CD) diagnostic guidelines aimed to guide physicians in accurately diagnosing CD and permit omission of duodenal biopsies in selected cases. Here, an updated and expanded evidence-based guideline is presented.

METHODS

Literature databases and other sources of information were searched for studies that could inform on 10 formulated questions on symptoms, serology, HLA genetics, and histopathology. Eligible articles were assessed using QUADAS2. GRADE provided a basis for statements and recommendations.

RESULTS

Various symptoms are suggested for case finding, with limited contribution to diagnostic accuracy. If CD is suspected, measurement of total serum IgA and IgA-antibodies against transglutaminase 2 (TGA-IgA) is superior to other combinations. We recommend against deamidated gliadin peptide antibodies (DGP-IgG/IgA) for initial testing. Only if total IgA is low/undetectable, an IgG-based test is indicated. Patients with positive results should be referred to a paediatric gastroenterologist/specialist. If TGA-IgA is ≥10 times the upper limit of normal (10× ULN) and the family agrees, the no-biopsy diagnosis may be applied, provided endomysial antibodies (EMA-IgA) will test positive in a second blood sample. HLA DQ2-/DQ8 determination and symptoms are not obligatory criteria. In children with positive TGA-IgA <10× ULN at least 4 biopsies from the distal duodenum and at least 1 from the bulb should be taken. Discordant results between TGA-IgA and histopathology may require re-evaluation of biopsies. Patients with no/mild histological changes (Marsh 0/I) but confirmed autoimmunity (TGA-IgA/EMA-IgA+) should be followed closely.

CONCLUSIONS

CD diagnosis can be accurately established with or without duodenal biopsies if given recommendations are followed.

Role of HLA-DQ typing and anti-tissue transglutaminase antibody titers in diagnosing celiac disease without duodenal biopsy in type 1 diabetes: A study of the population-based pediatric type 1 diabetes cohort of Western Australia

AIM

The primary aim of the present study was to determine if it is cost effective to use human leukocyte antigen (HLA) typing as a first-line screening test for celiac disease (CD) in children with type 1 diabetes (T1D), as recommended by the European Society of Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN). The second aim was to investigate whether anti-tissue transglutaminase IgA (anti-tTGA) antibodies can be used to diagnose CD without the need for a confirmatory duodenal biopsy in T1D.

METHODS

Data for all T1D patients aged <18 years, who attended the diabetes clinics in Western Australia up to June 2017, were extracted from the Western Australian Children's Diabetes Database (WACDD) and analyzed for their demographic data and CD permissive HLA alleles (DQ2, DQ8, and DQ7). For T1D patients already diagnosed with CD, the mode of diagnosis of CD, anti-tTGA titers, and CD permissive HLA alleles were analyzed.

RESULTS

Of the 936 eligible T1D patients identified, HLA-DQ typing was available for 551 (59%). Of these 551 patients, 504 (91.2%) were positive for celiac permissive HLA alleles. Eight percent (n = 75) of the T1D patients had a co-diagnosis of CD. High anti-tTGA titers were observed in those who were diagnosed with a positive duodenal biopsy.

CONCLUSION

HLA-DQ typing is not cost effective as a first-line screening test for CD in T1D patients because of over-representation of CD permissive HLA alleles in this group. Anti-tTGA titers may be useful in diagnosing CD in T1D without duodenal biopsy, as high levels were found to be strongly predictive of CD.

Tissue Transglutaminase Antibody and Its Association with Duodenal Biopsy in Diagnosis of Pediatric Celiac Disease

PURPOSE

This study aimed to evaluate a possible association between the anti-tissue transglutaminase antibody (anti-tTG) titer and stage of duodenal mucosal damage and assess a possible cut-off value of anti-tTG at which celiac disease (CD) may be diagnosed in children in conjunction with clinical judgment.

METHODS

This observational study was conducted at a gastroenterology clinic in a tertiary hospital from April 2012 to May 2013. Seventy children between 6-months and 18-years-old with suspected CD underwent celiac serology and duodenal biopsy. Statistical analyses were done using SPSS 16. Diagnostic test values were determined for comparing the anti-tTG titer with duodenal biopsy. An analysis of variance and Tukey-Kramer tests were performed for comparing the means between groups. A receiver operating characteristics curve was plotted to determine various cut-off values of anti-tTG.

RESULTS

The mean antibody titer increased with severity of Marsh staging (p<0.001). An immunoglobulin (Ig) A-tTG value at 115 AU/mL had 76% sensitivity and 100% specificity with a 100% positive predictive value (PPV) and 17% negative predictive value (NPV) for diagnosis of CD (p<0.001, 95% confidence interval [CI], 0.75-1).

CONCLUSION

There is an association between the anti-tTG titer and stage of duodenal mucosal injury in children with CD. An anti-tTG value of 115 AU/mL (6.4 times the upper normal limit) had 76% sensitivity, 100% specificity, with a 100% PPV, and 17% NPV for diagnosing CD (95% CI, 0.75-1). This cut-off may be used in combination with clinical judgment to diagnose CD.

Celiac disease and severe vitamin D deficiency: the case for anti-tissue transglutaminase antibody screening

Vitamin D-deficient Saudi adolescent girls were screened for anti-tissue transglutaminase (IgA-tTG) antibodies to determine whether the presence of severe vitamin D deficiency was associated with celiac disease. All 9 participants who were positive for IgA-tTG antibodies had severe vitamin D deficiency (25(OH)D < 12.5 nmol/l), suggesting that this population should be screened for celiac disease.

PURPOSE

The current cross-sectional study aimed to see if severe vitamin D deficiency is associated with celiac disease (CD) among Saudi adolescent girls.

METHODS

A total 200 adolescent females aged 13-19 years old with vitamin D deficiency (serum 25(OH)D < 50 nmol/l) were screened for IgA tTG (anti-tissue transglutaminase antibodies).

RESULTS

Of the 200 girls, 9 (4.5%) were positive for IgA tTG antibodies; all of whom had serum 25(OH)D < 12.5 nmol/l. A strong significant inverse association was observed between tTG antibody levels and serum 25(OH)D (R = - 0.53; p < 0.001) among antibody negative participants. Finally, participants with positive IgA tTG antibodies was 37.2 times higher for participants with 25(OH)D < 12.5 nmol/l than those whose vitamin D status was higher [OR = 37.2 (95% CI 4.6-299.7) (p = 0.0002)].

CONCLUSION

The data suggests that CD maybe a risk factor for severe vitamin D deficiency and that patients presenting with very low levels of 25(OH)D of less than 12.5 nmol/l-in the absence of an obvious cause-may need to be screened for CD.

Serology-based criteria for adult coeliac disease have excellent accuracy across the range of pre-test probabilities

BACKGROUND

The revised paediatric criteria for coeliac disease allow omission of duodenal biopsies in symptomatic children who have specific serology and coeliac disease-associated genetics. It remains unclear whether this approach is also applicable for adults with various clinical presentations.

AIM

To evaluate the accuracy of serology-based criteria in adults with variable pre-test probabilities for coeliac disease.

METHODS

Three study cohorts comprised adults with high-risk clinical coeliac disease suspicion (n = 421), moderate-risk family members of coeliac disease patients (n = 2357), and low-risk subjects from the general population (n = 2722). Serological and clinical data were collected, and "triple criteria" for coeliac disease comprised transglutaminase 2 antibodies >10× the upper limit of normal, positive endomysium antibodies, and appropriate genetics without requirement of symptoms. The diagnosis was based on intestinal biopsy.

RESULTS

The diagnosis of coeliac disease was established in 274 subjects. Of these, 59 high-risk subjects, 17 moderate-risk subjects, and 14 low-risk subjects fulfilled the "triple criteria". All had histologically proven coeliac disease, giving the criteria a positive predictive value of 100%. Altogether, 90 (33%) of all 274 newly diagnosed patients could have avoided biopsy, including 37% among high-risk, 20% among moderate-risk, and 48% among low-risk patients. No histological findings other than coeliac disease were found in the biopsies of "triple positive" subjects.

CONCLUSIONS

Coeliac disease can reliably and safely be diagnosed without biopsy in adults fulfilling the "triple criteria" regardless of the pre-test probability. Revised criteria would enable the number of endoscopies to be reduced by one-third.

Prevalence and Clinical Features of Celiac Disease in Healthy School-Aged Children

BACKGROUND/AIMS

The aim of this study was to determine the prevalence of celiac disease (CD) in healthy school-aged children in the northern region of Cyprus and to investigate the existence of potential markers that may accompany CD. This is the first study to measure the prevalence of CD in the northern region of Cyprus.

METHODS

This study included 3792 school-aged children who were between the ages of 6 and 10 years between January 2015 and October 2016. CD was screened using total serum IgA, IgA anti-tissue transglutaminase (tTG), and IgA antiendomysial (EMA) antibodies. Subjects with selective IgA deficiency were further tested for IgG-tTG. Small intestinal biopsies were performed on all subjects with tTG antibody positivity. Risk factors and symptoms related to CD were evaluated using questionnaires in both the CD and control groups.

RESULTS

Of the 3792 subjects, 39 were antibody positive (IgA-tTG was positive only in 14 subjects, IgA-tTG plus IgA-EMA in 21 subjects, and IgG-tTG in 4 subjects). IgA deficiency was detected in 11 subjects (0.29%). IgG-tTG was positive in 4 subjects with IgA deficiency (36.3%). Intestinal biopsies were performed on 28 of the 39 seropositive subjects. The biopsy findings of 15 children were consistent with CD (IgA-tTG positive in 3, IgA-tTG and IgA-EMA positive in 10, and IgG-tTG positive in 2). Thus, biopsies confirmed CD in 1:256 children (0.39%).

CONCLUSIONS

Our study, which is the first study of school-aged children from the northern region of Cyprus, revealed that CD is a prevalent disease in this region.

Can High Titres of Anti Tissue Transglutaminase Antibodies Reduce the Need for Intestinal Biopsy for Diagnosis of Celiac Disease?

Traditionally small intestinal biopsy has been considered a gold standard for the diagnosis of celiac disease (CD). But now data has shown that serological markers like anti-tissue-transglutaminase antibodies (tTGA) can be used to make the diagnosis with great sensitivity and specificity. The objective of the present study was to evaluate whether patients with high probability of CD and high titre of tTGA, have a high probability of intestinal damage and may not require biopsy for final diagnosis. All the cases with tTGA levels ≥15 IU/ml and who subsequently underwent biopsy from July 2010 to June 2013 were selected. Histopathological findings graded as per Marsh classification were correlated with serum tTGA levels. Grade 3 lesions were considered diagnostic for the disease. Out of total 731 patients 470 had serum tTGA levels >100 IU/ml and 261 patients had <100 IU/ml. Highest levels of tTGA (219.3 IU/ml) were seen in grade 3c which was >12 times the normal cutoff value. Mean serum tTGA in higher histological grade i.e. 3 (3a, 3b, 3c) was 186.7 IU/ml (>12 times the normal cut off value) as compared to grade 1 which was 108.9 IU/ml (>7 times the normal cut off value). Using a tTGA cutoff value of 70 IU/ml, sensitivity was found to be 83.9% while specificity was 56.10% with an overall accuracy of 77.7%. This study confirms that a small intestinal biopsy is not always necessary for the diagnosis of CD in symptomatic patients with high tTGA levels (>70 IU/ml).

Challenges in the Standardization of Autoantibody Testing: a Comprehensive Review

Standardization and harmonization are complementary tools to achieve higher testing quality in laboratory medicine. Both are of great relevance and are strongly needed in autoimmune diagnostics, due to the impressive advance in basic research and technological development observed in this diagnostic field in recent years that has led to the introduction of many new tests and new analytical methods. It is, therefore, essential that this strong innovative thrust is translated into clinical practice in a coordinated way to avoid confusion and the risk of potentially harmful errors for the patient. However, while standardization of antibody assays is a very complex task, harmonization of procedures and behaviors is a more feasible target and should necessarily include all the phases of the total testing process-in the pre-analytical phase, appropriateness of test requests, harmonization of autoantibody terminology, and adoption of uniform nomenclature for laboratory tests; in the analytical phase, harmonization of measurements, and sharing of test profiles and diagnostic algorithms; and in the post-analytical phase, harmonization of data reporting, and criteria for interpreting immunoserological results, especially harmonization of units, reference intervals, decision limits, and definition and notification of critical values. We here provide and discuss some examples of harmonization initiatives related to anti-nuclear antibodies, TSH receptor, and anti-thyroid peroxidase antibodies and to antibodies associated with autoimmune hepatitis and with celiac disease. These initiatives could be the starting steps to achieve a wider consensus and a closer interaction among stakeholders in the path of autoimmune diagnostics harmonization to enhance clinical effectiveness and provide greater patient safety.

The identification of celiac disease in asymptomatic children: the Generation R Study

BACKGROUND

The objective of our study was to assess whether TG2A levels in the healthy childhood population can be predictive of subclinical CD.

METHODS

A total of 4442 children (median age, 6.0 years) participating in a population-based prospective cohort study were screened on serum TG2A. Those with positive TG2A (≥7 U/ml; n = 60, 1.4%) were invited for clinical evaluation (median age, 9.0 years). Medical history, physical examination, serum TG2A, and IgA-endomysium (EMA) were assessed, as well as HLA DQ 2.2/2.5/8 typing. Patients with positive serologies and genetic risk types underwent duodenal biopsies. TG2A levels at the time of biopsy were compared with the degree of enteropathy.

RESULTS

Fifty-one TG2A-positive children were included in the follow-up: 31 (60.8%) children had CD, ten (19.6%) did not have CD, and ten (19.6%) were considered potential CD cases because of inconclusive serologies. Duodenal biopsies were performed in 26/31 children. CD with Marsh 3a/b enteropathy was observed in 75% (15/20) of children having TG2A levels ≥10ULN at 6 years of age, as well as in 75% (6/8) of children having a positive TG2A <10 ULN (OR 1.00; 95% CI 0.15-6.64). CD cases had a lower BMI SDS (mean -0.49, SD 0.92) than children without CD (mean 0.47, SD 1.37; p = 0.02). No differences were observed in gastrointestinal symptoms.

CONCLUSIONS

Serum TG2A screening at 6 years of age in the healthy childhood population has a positive predictive value of 61% to detect subclinical CD. We did not find a positive correlation between serum TG2A levels and the degree of enteropathy.

Younger age at diagnosis predisposes to mucosal recovery in celiac disease on a gluten-free diet: A meta-analysis

BACKGROUND AND AIMS

Persistent intestinal damage is associated with higher complication rates in celiac disease. We aimed to assess the potential modifiers of mucosal recovery.

MATERIALS AND METHODS

We screened databases (PubMed, Embase, Cochrane Trials, and Web of Science) for papers on celiac disease. Papers discussing (1) celiac patients (2) follow-up biopsy and (3) mucosal recovery after commencement of a gluten-free diet were included. The primary outcome was to produce a comprehensive analysis of complete mucosal recovery (i.e., Marsh 0 on follow-up). We compared children's recovery ratios to those of adults. Patients following a strict gluten-free dietary regimen were included in a subgroup. Summary point estimates, 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated. Heterogeneity was tested with I2-statistic. The PROSPERO registration number is CRD42016053482.

RESULTS

The overall complete mucosal recovery ratio, calculated from 37 observational studies, was 0.36 (CI: 0.28-0.44, PI: -0.12-0.84; I2: 98.4%, p<0.01). Children showed higher complete mucosal recovery ratio than adults (p<0.01): 0.65 (CI: 0.44-0.85, PI: -0.10-1.39; I2: 96.5%, p<0.01) as opposed to 0.24 (CI: 0.15-0.33, PI: -0.19-1.08; I2: 96.3%, p<0.01). In the strict dietary adherence subgroup, complete mucosal recovery ratio was 0.47 (CI: 0.24-0.70, PI: -0.47-1.41; I2: 98.8%, p<0.001). On meta-regression, diagnostic villous atrophy (Marsh 3) ratio (-8.97, p<0.01) and male ratio (+6.04, p<0.01) proved to be a significant determinant of complete mucosal recovery, unlike duration of gluten-free diet (+0.01, p = 0.62). The correlation between complete mucosal recovery ratio and age on diagnosis is of borderline significance (-0.03, p = 0.05).

CONCLUSIONS

There is considerable heterogeneity across studies concerning complete mucosal recovery ratios achieved by a gluten-free diet in celiac disease. Several celiac patients fail to achieve complete mucosal recovery even if a strict dietary regimen is followed. Younger age on diagnosis, less severe initial histologic damage and male gender predispose for achieving mucosal recovery.

Application of the Biopsy-Sparing ESPGHAN Guidelines for Celiac Disease Diagnosis in Adults: A Real-Life Study

BACKGROUND

Current adult celiac disease diagnosis requires histological confirmation. However, pediatric guidelines have proposed biopsy-sparing algorithms.

AIMS

To explore the applicability of the ESPGHAN criteria and assess the accuracy of serology in predicting disease in adults.

METHODS

We evaluated 234 consecutive adults showing elevated anti-tTG titers, EMA-positivity, and genetic susceptibility. Patients underwent upper endoscopy with duodenal biopsy. We determined optimal anti-tTG cutoff levels using ROC curves.

RESULTS

Mean anti-tTG levels were 71.1 ± 66.5 U/ml; mean normalized levels were 14.8 ± 14.1 × ULN (mean ± SD). Partial/total villous atrophy was present in 36%/55% of cases, respectively. Anti-tTG levels correlated with histology (r _s = 0.397, p < 0.001). AUC was similar before and after normalization (0.803 vs 0.807). Applying the ESPGHAN criterion (≥10 × ULN), we calculated a 97.66% PPV. ROC curve analysis showed an optimal cutoff of ≥16 × ULN, with a PPV of 98.86%. Eleven different assays were used for anti-tTG titer determination: Two were prevalent, labeled A (n = 141) and B (n = 59). They performed differently regarding disease prediction (AUC = 0.689 vs 0.925, p < 0.01), showing distinct optimal cutoff values (14.3 × ULN vs 3.7 × ULN), even after standardization (-0.14 vs -1.2).

CONCLUSION

In adult symptomatic patients showing EMA-positivity and genetic susceptibility, anti-tTG titers correlated with histology. ESPGHAN criteria performed similarly to previous studies. However, a calculated 16 × ULN cutoff showed an improved PPV. Among prevalent assays, PPV peaked differently both after normalization and standardization, indicating intrinsic differences in performance, thus preventing uniform prediction of disease in a real-life setting. Assay-specific optimal cutoffs seem possible, but would complicate diagnostic criteria. However, biopsy-sparing strategies in adults could prove useful in challenging patients.

Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients

HIGHLIGHTS

What is already known about this subject?

Celiac disease (CD) has a high clinical and histological diversity and the mechanisms underlying this phenomenon remain elusive.

H. pylori is a bacterium that chronically infect gastric and duodenal mucosa activating both a Th1/Th17 and T-reg pathways.

The role of H. pylori (and the effect of their virulence factors) in CD have not yet completely elucidated.

What are the new findings?

cagA+ H. pylori strains are associated to milder histological damage in infected CD patients.

In active-CD patients the presence of cagA+ H. pylori is associated to an increase in T-reg markers, contrasting with a downregulation in cagA+ infected potential-CD individuals.

How might it impact on clinical practice in the foreseeable future?

The identification of microbiological factors that could modulate inflammation and clinical expression of CD may be used in the future as preventive strategies or as supplementary treatment in patients that cannot achieve complete remission, contributing to the better care of these patients.

Background: Mechanisms underlying the high clinical and histological diversity of celiac disease (CD) remain elusive. Helicobacter pylori (Hp) chronically infects gastric and duodenal mucosa and has been associated with protection against some immune-mediated conditions, but its role (specifically of cagA+ strains) in CD is unclear.

Objective: To assess the relationship between gastric Hp infection (cagA+ strains) and duodenal histological damage in patients with CD.

Design: Case-control study including patients with active-CD, potential-CD and non-celiac individuals. Clinical presentation, HLA genotype, Hp/cagA gene detection in gastric mucosa, duodenal histology, Foxp3 positive cells and TGF-β expression in duodenal lamina propria were analyzed.

Results: We recruited 116 patients, 29 active-CD, 37 potential-CD, and 50 non-CD controls. Hp detection was similar in the three groups (~30–40%), but cagA+ strains were more common in infected potential-CD than in active-CD (10/11 vs. 4/10; p = 0.020) and non-CD (10/20; p = 0.025). Among active-CD patients, Foxp3 positivity was significantly higher in subjects with cagA+ Hp+ compared to cagA- Hp+ (p < 0.01) and Hp- (p < 0.01). In cagA+ Hp+ individuals, Foxp3 positivity was also higher comparing active- to potential-CD (p < 0.01). TGF-β expression in duodenum was similar in active-CD with cagA+ Hp+ compared to Hp- and was significantly downregulated in cagA+ potential-CD subjects compared to other groups.

Conclusion: Hp infection rates were similar among individuals with/without CD, but infection with cagA+ strains was associated with milder histological damage in celiac patients infected by Hp, and in active-CD cases with higher expression of T-reg markers. Results suggest that infection by cagA+ Hp may be protective for CD progression, or conversely, that these strains are prone to colonize intestinal mucosa with less severe damage.

Antitissue Transglutaminase Normalization Postdiagnosis in Children With Celiac Disease

OBJECTIVES

Limited pediatric data exist examining the trend and predictors of antitissue transglutaminase (atTG) normalization over time in children with celiac disease (CD). We aimed to evaluate time to normalization of atTG in children after CD diagnosis, and to assess for independent predictors affecting this duration.

METHODS

A retrospective chart review was completed in pediatric patients with CD diagnosed from 2007 to 2014 at the Stollery Children's Hospital Celiac Clinic (Edmonton, Alberta, Canada). The clinical predictors assessed for impact on time to atTG normalization were initial atTG, Marsh score at diagnosis, gluten-free diet compliance (GFDC), age at diagnosis, sex, ethnicity, medical comorbidities, and family history of CD. Kaplan-Meier survival analysis was completed to assess time to atTG normalization, and Cox regression to assess for independent predictors of this time.

RESULTS

A total of 487 patients met inclusion criteria. Approximately 80.5% of patients normalized atTG levels. Median normalization time was 407 days for all patients (95% confidence interval [CI: 361-453]), and 364 days for gluten-free diet compliant patients (95% CI [335-393]). Type 1 diabetes mellitus (T1DM) patients took significantly longer to normalize at 1204 days (95% CI [199-2209], P < 0.001). Cox regression demonstrated T1DM (hazard ratio = 0.36 [0.24-0.55], P < 0.001) and higher baseline atTG (hazard ratio = 0.52 [0.43-0.63], P < 0.001) were significant predictors of longer atTG normalization time. GFDC was a significant predictor of earlier normalization (OR = 13.91 [7.86-24.62], P < 0.001).

CONCLUSIONS

GFDC and lower atTG at diagnosis are predictors of earlier normalization. Patients with T1DM are less likely to normalize atTG levels, with longer normalization time. Additional research and education for higher-risk populations are needed.

Coeliac disease: further evidence that biopsy is not always necessary for diagnosis

OBJECTIVES

Growing evidence supports the view that the diagnosis of coeliac disease (CD) can be made by serological tests alone, although this approach is still not widely accepted. We previously showed in retrospective and prospective studies that in adults an IgA-tissue transglutaminase antibody cut-off can be defined above which the positive predictive value for CD is 100%. Following a change in the analytical method for measuring the antibody, our objectives were to re-examine this finding in a larger series of adults to ascertain whether a diagnosis of CD can be reliably made in a proportion of patients without the need for small bowel biopsy and to re-evaluate the diagnostic guidelines used in our centre.

PATIENTS AND METHODS

A retrospective analysis was done in an unselected series of 270 adult patients who had small bowel biopsies and serum IgA-tissue transglutaminase antibody levels measured from 2009 to 2014.

RESULTS

At an IgA-tissue transglutaminase antibody cut-off greater than 45 U/ml (>8×upper limit of normal+2SDs) the positive predictive value for CD in this cohort was 100%; 40% of cases were above this cut-off.

CONCLUSION

We have verified that a diagnosis of CD can be reliably made in a high proportion of adults based on serology alone using the IgA-tissue transglutaminase antibody method specified. These results add to the body of evidence that small bowel biopsy should no longer be considered mandatory for the diagnosis of CD. On the basis of these results the diagnostic guidelines in our centre have been modified.

Is the Diagnosis of Celiac Disease Possible Without Intestinal Biopsy?

BACKGROUND

Coeliac disease is defined as a state of immune-mediated hyper-responsiveness to dietary gluten from wheat, barley, or rye in genetically predisposed individuals that results in tissue damage. The diagnosis is made by microscopic examination of a small intestinal biopsy, although serological testing for antibodies against tissue transglutaminase and deamidated gliadin peptide can be of great advantage. It has been suggested that duodenal biopsy can be avoided in patients with high levels of the tissue transglutaminase antibody, since a relationship has been found to be present between tissue transglutaminase antibody titres and coeliac disease.

AIMS

To study the correlation between tissue transglutaminase titre and small intestinal biopsy findings in patients with coeliac disease.

STUDY DESIGN

Diagnostic accuracy study.

METHODS

Ninety-five cases of patients diagnosed with coeliac disease and with positive serum tissue transglutaminase titres were retrieved from the Jordan University Hospital archives between December 2014 and December 2015. All the cases were classified according to the Marsh classification.

RESULTS

Ninety-five cases with a positive titre for the antibody were included in this study, 73 (76.8%) of them were females and 22 cases (23.2%) were males. The age of the patients ranged between 4 and 75 years with a mean age ± standard deviation of 32.3±14.7. The sensitivity was the highest in Marsh IIIC and lowest in Marsh IIIA (95% versus 68% respectively). The specificity was moderate (76%) for all subtypes of Marsh III.

CONCLUSION

This study showed a positive correlation between the tissue transglutaminase titre and the degree of duodenal damage (Marsh IIIC) in patients with coeliac disease. In the presence of high tissue transglutaminase levels, duodenal biopsy might not be always necessary for diagnosis, particularly in symptomatic patients.

Identification of Pediatric Patients With Celiac Disease Based on Serology and a Classification and Regression Tree Analysis

BACKGROUND & AIMS

Celiac disease is detected using serology and endoscopy analyses. We used multiple statistical analyses of a geographically isolated population in the United States to determine whether a single serum screening can identify individuals with celiac disease.

METHODS

We performed a retrospective study of 3555 pediatric patients (18 years old or younger) in the intermountain West region of the United States from January 1, 2008, through September 30, 2013. All patients had undergone serologic analyses for celiac disease, including measurement of antibodies to tissue transglutaminase (TTG) and/or deamidated gliadin peptide (DGP), and had duodenal biopsies collected within the following year. Modified Marsh criteria were used to identify patients with celiac disease. We developed models to identify patients with celiac disease using logistic regression and classification and regression tree (CART) analysis.

RESULTS

Single use of a test for serum level of IgA against TTG identified patients with celiac disease with 90% sensitivity, 90% specificity, a 61% positive predictive value (PPV), a 90% negative predictive value, and an area under the receiver operating characteristic curve value of 0.91; these values were higher than those obtained from assays for IgA against DGP or IgG against TTG plus DGP. Not including the test for DGP antibody caused only 0.18% of celiac disease cases to be missed. Level of TTG IgA 7-fold the upper limit of normal (ULN) identified patients with celiac disease with a 96% PPV and 100% specificity. Using CART analysis, we found a level of TTG IgA 3.2-fold the ULN and higher to most accurately identify patients with celiac disease (PPV, 89%). Multivariable CART analysis showed that a level of TTG IgA 2.5-fold the ULN and higher was sufficient to identify celiac disease in patients with type 1 diabetes (PPV, 88%). Serum level of IgA against TTG in patients with versus those without trisomy 21 did not affect diagnosis predictability in CART analysis.

CONCLUSIONS

In a population-based study, we found that serum level of IgA against TTG can identify patients with celiac disease with PPVs of about 90%. Predictive values increase greatly when levels are markedly above the ULN or when the assay is used in combination with other variables. Measurement of IgG against TTG or DGP does not increase the accuracy of detection of celiac disease based against TTG IgA levels. There is a low risk of false-positive results from serologic analysis in patients with type I diabetes or persistent increases in antibody against TTG on repeat testing.

Celiac disease: a clinical review

Celiac disease (CD) is an immune-mediated inflammatory enteropathy triggered by gluten exposure in genetically susceptible individuals. It has a high prevalence approaching 1% of the US population. A high index of suspicion is warranted to diagnose CD as frequently patients present with extraintestinal or atypical manifestations. CD is diagnosed by a combination of serum serologies and duodenal biopsies. The majority of patients will respond to a lifelong gluten-free diet which is the cornerstone of therapy. Complications such as refractory CD, ulcerative jejunoileitis, enteropathy associated T-cell lymphoma and small bowel adenocarcinoma occur in a minority of patients.

Tissue Transglutaminase Levels Are Not Sufficient to Diagnose Celiac Disease in North American Practices Without Intestinal Biopsies

BACKGROUND

Celiac serology is crucial for the diagnosis of celiac disease in children. The American guideline for celiac disease in children suggested that positive serology should be followed by confirmatory intestinal histology. The relationship between high tissue transglutaminase titers and celiac disease in children has not been well investigated in children from North America.

AIMS

In the present study, we investigated whether different tissue transglutaminase titers in symptomatic children could predict celiac disease without the confirmation of intestinal histology.

METHODS

Data from biopsy confirmed celiac children were collected from four different clinics in North America. Clinical, serological, histological, and follow-up data were collected. The accuracy rates of various tissue transglutaminase titers to predict celiac disease in children were calculated.

RESULTS

The data from 240 children were calculated. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of tissue transglutaminase titers at ≥10× upper limit of normal were 75.4, 48.8, 87.7, 29.0, and 70.8 %, respectively. Similar data were noted in the other tissue transglutaminase titers (≥3× upper limit of normal, >100 U/ml, or >100 U/ml and >10× upper limit of normal).

CONCLUSIONS

The positive predictive value of tissue transglutaminase titers at ≥3× upper limit of normal or higher was too low to predict celiac disease in children. Our data suggested that in routine clinical practice, high titers of tissue transglutaminase are not sufficient to diagnose celiac disease in North American children without intestinal biopsies.

Correlation Between Cut-off Level of Tissue Transglutaminase Antibody and Marsh Classification

BACKGROUND

Duodenal biopsy is required for diagnosis of celiac disease in adults, although some studies have suggested adequate accuracy of serology alone.

Objective: We aimed to assess the correlation between anti-tissue transglutaminase (tTG) titer and pathological findings and to define the specific level of tTG for predicting celiac disease in adults without the need for biopsy sampling.

METHODS

This descriptive study was done on 299 participants. The tTG titer and pathological findings of duodenal biopsy samples were used for this study. Analysis of Receiver operating characteristic (ROC) curve was used to find a cut-off point of anti-tTG antibody for mucosal atrophy.

RESULTS

Mean tTG titers was significantly higher in patients graded as Marsh III≥ 3 (p=0.023). ROC curve analysis showed 89.1% sensitivity for cut-off point≥76.5 IU/mL of anti-tTG. For Marsh≥ II, specificity was 28% and positive predictive value was 91%.CON

CLUSION

There is a linear correlation between increasing tTG level and Marsh I to III. Specificity of tTG titer more than 200 was 100% for Marsh >2.

Association of Tissue Transglutaminase Antibody Titer with Duodenal Histological Changes in Children with Celiac Disease

Celiac disease is usually diagnosed by demonstrating gluten enteropathy in small bowel biopsy. Celiac specific antibodies are used as an initial screening test. The goal of this study is to test the relationship of the anti-tTG titer and severity of histological changes in Jordanian children with celiac disease. Method. The medical records of 81 children who had elevated anti-tTG titer and had duodenal biopsies available were retrospectively reviewed. Result. Assessing the association of anti-tTG titer with duodenal histopathological changes, 94% of those with high anti-tTG titer (≥180 U/mL) had histological evidence of celiac disease. There was statistically significant positive association between high anti-tTG titer and Marsh grading as 82% of patients with Marsh III had high anti-tTG titer (Chi² 18.5; P value 0.00; Odds Ratio 8.5). The fraction of patients with Marsh III who were correctly identified as positive by anti-tTG titer ≥ 180 U/mL was high (sensitivity = 81.6). Moreover, the fraction of patients with anti-tTG titer ≥ 180 U/mL who had Marsh III was also high (positive predictive value = 78.4). Conclusion. Anti-tTG titer ≥ 180 U/mL had significant positive association with Marsh III histopathological changes of celiac disease.

Prevalence of celiac disease in first-degree relative of children in Sistan and Baluchestan province (Iran)

OBJECTIVE

To determine the prevalence of elevated antibodies and histological changes of celiac disease (CD) on intestinal biopsies among first-degree relatives (FDR) of Iranian children with known CD and to describe the characteristics of the affected FDR.

METHOD

The FDR of 119 patients with CD in Iran were tested for tissue transglutaminase (TTG) and immunoglobulin A (IgA) levels. Upper endoscopy and duodenal biopsy were recommended to those with elevated TTG-IgA antibodies. The characteristics and clinical features of all CD patients were recorded.

RESULTS

Altogether 480 FDR (52.7% females) participated in the study, of whom 63 had an elevated TTG-IgA and 44 consented to undergo endoscopy with biopsies. Histology revealed Marsh 0 in six, Marsh I in seven, Marsh II in four and Marsh III in 27. Most of those with Marsh II or III changes were siblings (26/31). The prevalence of TTG-IgA positivity among FDR was 13.1% and for biopsy-confirmed CD (Marsh II and III) it was 6.5%. Most FDR with CD had symptoms, with the most common being abdominal pain (45.0%), followed by musculoskeletal pain (35.5%) and constipation (25.8%). FDR with Marsh III changes had significantly higher levels of TTG-IgA.

CONCLUSIONS

The prevalence of CD in FDR in Iran is much higher compared with the general population (6.5% vs 0.5-0.6%). Testing should be considered for all FDR of Iranian patients with known CD and in particular in symptomatic cases.

THE PREVALENCE OF CELIAC DISEASE IN PATIENTS WITH IRON-DEFICIENCY ANEMIA IN CENTER AND SOUTH AREA OF IRAN

BACKGROUND

Celiac disease is an immune-mediated enteropathy due to a permanent sensitivity to gluten in genetically susceptible people. Iron-deficiency anemia is the most widely experienced anemia in humans. Iron-deficiency anemia additionally is a common extra intestinal manifestation of celiac disease.

OBJECTIVE

To investigate correlation between tTg levels and histological alterations and then to determine the prevalence of celiac disease in Center and South area patients of Iran with iron deficiency anemia.

METHODS

A total of 402 patients aged 12-78 years who presented with iron-deficiency anemia were included in this study. Hemoglobin, mean corpuscular volume and serum ferritin were determined. Venous blood samples for anti-tissue transglutaminase antibody immunoglobuline A and G were obtained from these patients. Upper gastrointestinal endoscopy was recommended to patients who had positive serology.

RESULTS

Of 402 patients with iron-deficiency anemia, 42 (10.4%) had positive serology for celiac disease. The small intestine biopsy of all patients with positive serology showed pathological changes (Marsh I, II & III). There was not significant difference in the mean hemoglobin level between iron-deficiency anemia patients with celiac disease and without celiac disease, duodenal biopsy results did not show significant relationship between the severity of pathological changes and levels of anti-tTG IgG (P -value: 0/869) but significant relationship was discovered between pathological changes and levels of anti-tTG IgA (P -value: 0/004).

CONCLUSION

Screening of celiac disease by anti-tissue transglutaminase antibody should be completed as a routine investigation in patients with iron-deficiency anemia. Also physicians must consider celiac disease as a possible reason of anemia in all patients with iron deficiency anemia.

A Canadian Study toward Changing Local Practice in the Diagnosis of Pediatric Celiac Disease

Background. The European Society for Pediatric Gastroenterology, Hepatology and Nutrition endorses serological diagnosis (SD) for pediatric celiac disease (CD). The objective of this study was to pilot SD and to prospectively evaluate gastrointestinal permeability and mucosal inflammation at diagnosis and after one year on the gluten-free diet (GFD). We hypothesized that SD would be associated with similar short term outcomes as ED. Method. Children, 3-17 years of age, referred for possible CD were eligible for SD given aTTG level ≥200 U/mL, confirmed by repeat aTTG and HLA haplotypes. Gastrointestinal permeability, assessed using sugar probes, and inflammation, assessed using fecal calprotectin (FC), at baseline and after one year on a GFD were compared to patients who had ED. Results. Enrolled SD (n = 40) and ED (n = 48) patients had similar demographics. ED and SD groups were not different in baseline lactulose: mannitol ratio (L : M) (0.049 versus 0.034; p = 0.07), fractional excretion of sucrose (%FES; 0.086 versus 0.092; p = 0.44), or fecal calprotectin (FC; 89.6 versus 51.4; p = 0.05). At follow-up, urine permeability improved and was similar between groups, L : M (0.022 versus 0.025; p = 0.55) and %FES (0.040 versus 0.047; p = 0.87) (p > 0.05). FC improved but remained higher in the SD group (37.1 versus 15.9; p = 0.04). Conclusion. Patients on the GFD showed improved intestinal permeability and mucosal inflammation regardless of diagnostic strategy. This prospective study supports that children diagnosed by SD have resolving mucosal disease early after commencing a GFD.

Immunoassays for the detection of IgA antibodies to tissue transglutaminase: significance of multiples of the upper limit of normal and inter-assay correlations

The presence of IgA antibodies to tissue transglutaminase (anti-tTg) is associated with variable risk for celiac disease. The use of common multiples of the upper limit of normal (ULN) has been suggested to optimize diagnostic pathways as well as improve harmonization between assays.

The characteristics of four anti-tTG IgA assays relative to endomysial IgA (EMA) by indirect immunofluorescence assay (IFA) as reference test were assessed. Commutability between anti-tTG immunoassays and/or EMA based on manufacturer’s recommended cut-off values and three common multiples of ULN (3×, 5× and 10×) was also investigated. Sera from 200 patients and 100 healthy individuals were analyzed.

At manufacturer’s cut-off; the sensitivities for the tTG assays ranged from 72.5% to 98.6% and specificities from 60.3% to 99.2%. The percent positive agreements between any anti-tTG and EMA or any two anti-tTG immunoassays varied from 56.7% to 98.0% and 46.7% to 100.0%, respectively. At 3×, 5× or 10× ULNs, the inter-rater reliability as measured by Cohen κ between any two anti-tTG assays were quite variable and ranged from 0.28 to 0.96, 0.26 to 0.89 or 0.13 to 0.78, respectively. Furthermore, the percent positive agreements between any two anti-tTg IgA immunoassays ranged from 83.1% to 98.2%, 92.0% to 100%, or 100%, at 3×, 5× or 10×, respectively.

Commutability between tTG IgA immunoassays or tTG IgA and EMA is kit-dependent and common multiples of the ULN are not sufficient to correct for inter-assay variations. Many factors influence the performance of anti-tTG IgA assays which limit their commutability.

The Spectrum of Differences between Childhood and Adulthood Celiac Disease

An old saying states that ''children are not little adults" and this certainly holds true for celiac disease, as there are many peculiar aspects regarding its epidemiology, diagnosis, clinical presentations, associated diseases, and response to treatment in pediatric compared to adult populations, to such an extent that it merits a description of its own. In fact, contrary to the past when it was thought that celiac disease was a disorder predominantly affecting childhood and characterized by a malabsorption syndrome, nowadays it is well recognized that it affects also adult and elderly people with an impressive variability of clinical presentation. In general, the clinical guidelines for diagnosis recommend starting with specific serologic testing in all suspected subjects, including those suffering from extraintestinal related conditions, and performing upper endoscopy with appropriate biopsy sampling of duodenal mucosa in case of positivity. The latter may be omitted in young patients showing high titers of anti-transglutaminase antibodies. The subsequent management of a celiac patient differs substantially depending on the age at diagnosis and should be based on the important consideration that this is a lifelong condition.

Are ESPGHAN "biopsy-sparing" guidelines for celiac disease also suitable for asymptomatic patients?

OBJECTIVES

In 2012, European Society of Pediatric Gastroenterology, Hepatology, and Nutrition published novel guidelines on celiac disease (CD) diagnosis. Symptomatic children with serum anti-transglutaminase (anti-tTG) antibody levels ≥10 times upper limit of normal (ULN) could avoid duodenal biopsies after positive HLA test and serum anti-endomysial antibodies (EMAs). So far, both asymptomatic and symptomatic patients with anti-tTG titer <10 times ULN should undergo upper endoscopy with duodenal biopsies to confirm diagnosis. The aim of this study was to assess the accuracy of serological tests to diagnose CD in asymptomatic patients.

METHODS

We retrospectively reviewed data of 286 patients (age range: 10 months to 17 years) with CD diagnosis based on elevated titer of anti-tTG, EMA positivity, and histology. All patients were distinguished between symptomatic and asymptomatic; histological lesions were graded according to the Marsh-Oberhuber (MO) criteria. Fisher exact test was applied to analyze both groups in terms of diagnostic reliability of serological markers.

RESULTS

A total of 196 patients (68.53%) had anti-tTG titers ≥10 times ULN. Among them, a group of 156 patients (79.59%) also had symptoms suggestive of CD ("high-titer" symptomatic); of these, 142 patients (91.02%) showed severe lesion degree (3a, 3b, 3c MO). Conversely, 40 out of 196 patients (20.40%) were asymptomatic ("high-titer" asymptomatic) and 37 patients (92.5%) of them showed severe lesion degree (3a, 3b, 3c MO). No difference in histological damage was found between "high-titer" symptomatic and "high-titer" asymptomatic children (Fisher exact test, P=1.000).

CONCLUSIONS

If confirmed in large multicenter prospective studies, the "biopsy-sparing" protocol seems to be applicable to both symptomatic and asymptomatic patients with anti-tTG titer ≥10 times ULN, positive EMA, and HLA-DQ2/DQ8.

The degree of mucosal damage to the small intestine and serum immunoglobulin G4 levels correlate with celiac disease

BACKGROUND

Celiac disease (CD) is an immune-mediated and chronic inflammatory enteropathy, triggered by the ingestion of gluten in genetically susceptible individuals. Immunoglobulin G4 (IgG4)-related diseases are a recently defined emerging clinical condition, characterized by increased serum IgG4 concentrations. The aim of this study was to investigate whether IgG4 levels correlate with the titers of intestinal antibodies and the degree of mucosal damage in CD patients.

MATERIALS AND METHODS

A total of 41 CD patients and 28 healthy controls were included in the study. All patients underwent a duodenal biopsy and were then diagnosed with the modified Marsh classification. Blood samples were obtained for IgG4 measurements. Serums were kept at -80 °C until the analysis was carried out and plasma IgG4 levels were determined using an enzyme-linked immune sorbent assay method with a diagnostic cutoff value of 135 mg/dl.

RESULTS

The mean age of the CD and the control group was 26.8 ± 8.3 and 26.9 ± 6.2 years, respectively. The mean IgG4 levels were significantly higher in CD patients (283.21 ± 39.02 mg/dl) compared with the healthy control group (68.97 ± 15.89 mg/dl, P<0.0001). In the CD group, 27/41 patients and in the control group, 4/28 patients had high IgG4 levels (>135 mg/dl, P < 0.0001). A close correlation was found between the grade of mucosal damage, IgG4 levels, and antigliadin-IgA; the higher the grade Marsh score, the higher the measured IgG4 (P < 0.05).

CONCLUSION

In our study, IgG4 levels of CD patients were higher than normal ranges whereas the results of the control group were within physiologic limits. We also showed for the first time that there was a correlation between IgG4 levels, autoantibody, and severity of mucosal damage. To the best of our knowledge, this is the first study to evaluate IgG4 levels and mucosal damage in CD patients.

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.

Appropriate clinical use of human leukocyte antigen typing for coeliac disease: an Australasian perspective

The past decade has seen human leukocyte antigen (HLA) typing emerge as a remarkably popular test for the diagnostic work-up of coeliac disease with high patient acceptance. Although limited in its positive predictive value for coeliac disease, the strong disease association with specific HLA genes imparts exceptional negative predictive value to HLA typing, enabling a negative result to exclude coeliac disease confidently. In response to mounting evidence that the clinical use and interpretation of HLA typing often deviates from best practice, this article outlines an evidence-based approach to guide clinically appropriate use of HLA typing, and establishes a reporting template for pathology providers to improve communication of results.

Titers of anti-tissue transglutaminase antibody correlate well with severity of villous abnormalities in celiac disease

GOALS

We reviewed our celiac disease (CeD) database to study if anti-tissue transglutaminase (tTG) antibody (ab) titers correlate with severity of villous abnormalities in Indian patients and to find out a cutoff value of anti-tTG ab fold-rise, which could best predict CeD.

BACKGROUND

Guidelines for diagnosing CeD suggest that biopsy could be avoided in some patients with high anti-tTG ab titer.

STUDY

We reviewed a cohort of 366 anti-tTG ab-positive individuals in whom duodenal biopsies were performed. Anti-tTG ab was obtained before initiation of gluten-free diet. Anti-tTG ab results were expressed in terms of fold-rise by calculating ratio of observed values with cutoff value. CeD was diagnosed if in addition to positive serology, patients had villous atrophy (>Marsh grade 2) and unequivocal response to gluten-free diet.

RESULTS

The mean anti-tTG fold-rise in groups with Marsh grade ≤2 was 2.6 (±2.5), grade 3a was 4.0 (±3.9), 3b was 5.7 (±5.1), and 3c was 11.8 (±8.0). The positive likelihood ratio for diagnosing CeD was 15.4 and 27.4 at 12- and 14-fold-rise of anti-tTG ab titer, respectively. The positive predictive value of diagnosis of CeD was 100% when anti-tTG ab titer was 14-fold higher over the cutoff value. Fifty-seven (43.9%) individuals with anti-tTG titer rise <2-fold high also had CeD.

CONCLUSIONS

As severity of villous abnormality increases, titer of anti-tTG also rises. Presence of villous atrophy can be predicted at very high anti-tTG ab titer. In contrast to emerging belief, mucosal biopsies should be performed even if anti-tTG ab titer is <2 times, because many patients with CeD have low titers.

Overview of biomarkers for diagnosis and monitoring of celiac disease

Among the adverse reactions caused by wheat, celiac disease (CD) is the longest studied and best-known pathology. The more recently defined non-celiac gluten sensitivity (NCGS) presents with symptoms which are often indistinguishable from CD. Diagnosis of CD is based on serologic, molecular, and bioptic testing. The IgA anti-transglutaminase (tTG) test is considered highly important, as it shows high sensitivity and specificity and its levels correlate to the degree of intestinal damage. Small bowel biopsy can be avoided in symptomatic patients with IgA anti-tTG levels above 10× the manufacturer's cut-off. Recently, tests of anti-deamidated peptides of gliadin (DGP) have replaced classic anti-native gliadin (AGA) tests. DGP assays have a considerably higher diagnostic accuracy than AGA assays, especially in the IgG class, and can replace anti-tTG tests in patients with selective IgA deficiency. The combination of IgG anti-DGP plus IgA anti-tTG assays show greater sensitivity than a single test, with very high specificity. EMA tests have great diagnostic accuracy but are not recommended by all the latest guidelines because they are observer dependent. Biopsy must still be considered the gold standard for CD diagnosis. HLA-DQ genotyping can be used to screen asymptomatic children and in cases of histology/serology disagreement. About half of NCGS patients are DQ2 positive and have IgG AGA. To diagnose NCGS, first CD and wheat allergy must be excluded; then the wheat dependence of symptoms must be verified by a gluten-free diet and subsequent gluten challenge.

Intestinal titres of anti-tissue transglutaminase 2 antibodies correlate positively with mucosal damage degree and inversely with gluten-free diet duration in coeliac disease

It has always been known that anti-tissue transglutaminase 2 (anti-TG2) antibodies are produced in the small intestine. Their serum titres correlate with mucosal damage degree and decrease on a gluten-free diet (GFD). We aimed to correlate intestinal anti-TG2 antibodies levels with degree of mucosal damage and GFD duration. Thirty-four active, 71 potential and 24 CD patients on GFD for at least 2 years were enrolled. Anti-TG2 deposits were detected in intestinal biopsies by double immunofluorescence. Biopsies were cultured for 24 h with medium, and with gliadin peptic tryptic digest (PTG) or A-gliadin peptide 31-43 (P31-43). Anti-TG2 antibodies secreted into supernatants were measured by enzyme-linked immunosorbent assay (ELISA). All active CD patients secreted high titres of anti-TG2 antibodies into culture medium that increased with the worsening of mucosal injury (Spearman's r = 0·71; P < 0·0001). Seventy of 71 potential CD patients and 15 of 24 treated CD patients secreted low titres of anti-TG2 antibodies into supernatants, eight of nine negative treated patients being on GFD for more than 10 years. An inverse correlation between antibody titres and duration of GFD was found, (Spearman's r = -0·52; P < 0·01). All active, 53 of 71 potential and six of 24 treated, CD patients showed anti-TG2 mucosal deposits. Five of six positive treated CD patients had been on GFD for fewer than 6 years and were also positive for secreted anti-TG2. In treated patients, PTG/P31-43 was not able to induce secretion of anti-TG2 antibodies into culture medium. Measurement of anti-TG2 antibodies in biopsy supernatants proved to be more sensitive than detection by immunofluorescence to reveal their intestinal production. Intestinal antiTG2 antibodies titres correlated positively with the degree of mucosal damage and inversely with the duration of GFD.