Duodenal biopsy may be avoided when high transglutaminase antibody titers are present

Exploring Total Immunoglobulin A's Impact on Non-Biopsy Diagnosis of Celiac Disease: Implications for Diagnostic Accuracy

OBJECTIVE

In the current debate surrounding the biopsy-free diagnosis of CeD, it is crucial to identify factors influencing the accuracy of results. This study investigated the impact of total IgA on the non-invasive diagnosis of celiac disease (CeD).

METHODS

We retrospectively assessed total IgA titers' influence on the diagnostic accuracy of different tTG-IgA thresholds compared to the upper reference value (UNL).

RESULTS

Of 165 included patients, tTG-IgA values at 10× UNL and 6× UNL showed specificity of 82.6% and 73.9% and sensitivity of 49.3% and 69.0%, respectively, in predicting intestinal villous atrophy (Marsh 3). In 130 patients, total IgA levels were known at baseline. These patients were divided into three tertiles according to total IgA, i.e., patients with lower, intermediate, or higher total IgA within the population. For patients with total IgA ≥ 245 mg/dL, using a tTG-IgA cutoff of 6× UNL instead of 10× UNL resulted in decreased specificity from 71.4% to 42.8% and increased sensitivity from 67.6% to 81.1%. For patients with total IgA < 174 mg/dL and between 174 mg/dL and 245 mg/dL, using a tTG-IgA cutoff of 6× UNL instead of 10× UNL maintained specificity (75.0% and 85.7%, respectively) with increased sensitivity (from 46.2% to 64.1% and from 36.1% to 52.8%, respectively).

CONCLUSIONS

In conclusion, total IgA influences the diagnostic accuracy of a predetermined tTG-IgA cutoff. Greater consideration should be given to total IgA, beyond its deficiency, in evaluating the applicability and accuracy of non-invasive CeD diagnosis.

Non-biopsy Strategy for the Diagnosis of Celiac Disease in Adults: A Narrative Review

Celiac disease (CeD) diagnosis is a complicated process, requiring a multi-step procedure and a high level of clinical knowledge. Some scientific societies, mainly from Europe and North America, have proposed appropriate guidelines for the diagnosis and management of CeD. Since duodenal biopsy is particularly challenging for children, guidelines of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition, presented in 2012 and updated in 2020, have made it possible to avoid the biopsy in symptomatic pediatric patients with high levels of IgA anti-transglutaminase. Several parallel, similar studies in adults support the non-biopsy strategy. However, several pros and cons exist in applying such a strategy. The present narrative review reports the current evidence and the implication of omitting biopsy in the diagnosis of CeD in adults.

Digesting gluten with oral endopeptidases to improve the management of celiac disease

In our editorial, we want to comment on the article by Stefanolo et al titled "Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet". Celiac disease is an immune-mediated disorder triggered by dietary gluten in genetically predisposed individuals. Although avoiding gluten can permit patients to live symptom-free, ongoing voluntary or involuntary exposure to gluten is common and associated with persistent villous atrophy in small bowel mucosa. As villous atrophy predisposes patients to life threatening complications, such as osteoporotic fractures or malignancies, therapeutic adjuncts to gluten-free diet become important to improve patients' quality of life and, if these adjuncts can be shown to improve villous atrophy, avoid complications. Oral administration of enzyme preparations, such as endopeptidases that digest gluten and mitigate its antigenicity to trigger inflammation, is one clinical strategy under investigation. The article is about the utility of one endopeptidase isolated from Aspergillus niger. We critique findings of this clinical trial and also summarize endopeptidase-based as well as other strategies and how they can complement gluten-free diet in the management of celiac disease.

Outcome in pediatric celiac disease is independent of the diagnostic approach in patients with high antibody levels

OBJECTIVES

European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines enable the diagnosis of celiac disease (CD) without biopsies in patients with immunoglobulin A (IgA)-antibodies against tissue transglutaminase (TGA-IgA) ≥ 10× the upper limit of normal (ULN) and positivity of endomysial antibodies in a second blood sample. Limited data exist comparing the biopsy versus the nonbiopsy diagnostic approach regarding long-term outcomes in CD patients. Our study aimed to investigate the influence of the diagnostic approach on adherence to gluten-free diet (GFD), serological remission (defined as normalization of TGA-IgA during follow-up (FU)) and clinical remission in CD patients with TGA-IgA ≥ 10× ULN.

METHODS

Retrospective multicenter study. Patients with CD and TGA-IgA ≥ 10× ULN at diagnosis were included in the study. Patients with confirmed diagnosis by biopsy were compared to patients diagnosed by nonbiopsy approach using univariate analysis, Kaplan-Meier survival curve, and logistic regression models.

RESULTS

A total of 282 CD patients (192 [68.1%] in the biopsy group; 90 [31.9%] in the nonbiopsy group) were analyzed. The median time to normalization of TGA-IgA was 16.5 months [interquartile range, IQR: 13, 28] in the biopsy and 15 months [IQR: 12, 26] in the nonbiopsy group; p = 0.14). Rates of normalized TGA-IgA at first to third-year FU were comparable between both groups. Adherence to GFD did not seem to be influenced by the diagnostic approach.

CONCLUSIONS

The nonbiopsy approach is not inferior to the biopsy approach in terms of adherence to GFD and serological remission in patients with CD.

Evaluation of the Prevalence of Anti-transglutaminase 2 and 6 Antibodies in Patients with Sero-Positive Multiple Sclerosis

Background

Gluten sensitivity (GS) is one of the gluten-related disorders (GRDs). Patients with GS may have serum antibodies against tissue transglutaminase (tTG) (IgA and IgG) without any evidence of enteropathy. We aimed to evaluate both tTG-6 and tTG-2 antibodies to determine the prevalence of seropositive tTG-2 and tTG-6 antibodies in patients with multiple sclerosis (MS).

Methods

In this cross-sectional study, we carried out serological tests (IgA & IgG anti-tTG-6 and tTG-2 antibodies) in patients with MS.

Results

Seventy-two patients with MS were included in this study. Of them, seropositive patients for total (IgA+IgG) of tTG-6 and tTG-2 autoantibodies were 9.7% (95% CI, 4.2-18) and 5.6% (95% CI, 1.4-12.5), respectively.

Conclusion

Anti-tTG-6 antibody testing may be necessary for early diagnosis of GS in patients with MS. More studies with larger sample sizes are warranted to confirm these data.

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.

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.

Celiac disease and idiopathic pulmonary hemosiderosis: A literature review of the Lane-Hamilton Syndrome

Lane-Hamilton syndrome (LHS) presents a medical emergency, with 14% mortality due to Idiopathic Pulmonary Hemosiderosis (IPH) in acute phase. Despite the clinical severity of this entity, there has been no published review in the international literature, resulting in lack of awareness and delayed diagnosis.A rigorous search of international databases yielded a total of 80 LHS cases from January 1971 to August 2020. We analyzed 44 children (8.56±4.72years, 21boys) and 36 adults (33.61±13.41years, 12men), to present the clinical manifestations, radiological and immunological pattern, therapeutic approaches and outcome of LHS. We also elaborated on clinical and laboratory findings' associations to propose diagnostic indexes and clarified differences based on age distribution.Celiac Disease (CD) and IPH diagnosis was made concurrently in 46 patients, whereas in 21 patients the diagnosis of LHS was delayed for 2.5y (3mo-11y). Hemoptysis (n=56, 70%), dyspnea (n=47, 58.8%), anemia (n=72, 90%) and iron deficiency (n=54, 67.5%) were most commonly observed. Medical history revealed recurrent episodes of hemoptysis (n=38) and persistent iron deficiency anemia (n=25) in need of multiple blood transfusions or iron supplementation. Patchy infiltrate opacities to consolidation predominated in children, whereas bilateral diffuse ground glass opacities in adults. Duodenal biopsy was performed in 66 cases (diagnostic 87.8%), BAL in 51 (diagnostic 74.5%) and surgical lung biopsy in 20. Anti-tTG titer was positive in all 24 (54.6%) children and 19 (52.8%) adults that documented this assay. Prednisone or methylprednisolone pulse therapy and GFD were initiated in the acute phase, whereas chronic therapy included GFD, along with long-term prednisone in refractory cases. Three cases with severe respiratory failure or hemodynamic instability were intubated and a further 3 succumbed.A thorough understanding of LHS may reveal further diagnostic indexes and a consensus on therapy guidelines. Screening for CD is essential in all IPH cases for timely recognition and favorable outcome.

Diagnosing Coeliac Disease During Mass-Screening of General Paediatric Population: Is Biopsy Avoidable?

OBJECTIVES

Studies evaluating the correlation between tissue transglutaminase immunoglobulin antibody (TGA-IgA) levels and the degree of enteropathy in screening-detected coeliac disease (CD) patients from the general childhood population are scarce. The objectives of our study were to evaluate the correlation between the TGA-IgA titre and the degree of enteropathy and to evaluate whether the no-biopsy approach to diagnose CD in symptomatic patients proposed by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition could be extended to asymptomatic CD patients diagnosed during mass screening studies.

METHODS

The present study is a sub-study of a cross-sectional mass screening study, "Exploring the Iceberg of Coeliacs in Saudi Arabia", conducted among school-aged children (6-15 years) in 2014-2015. The 93 biopsy-confirmed CD patients constituted the study cohort of the present study (mean age 11.4 ± 2.6 years; 24 males). TGA-IgA titres and endomysial antibodies (EMA) at the time of biopsy and grade of enteropathy were assessed, and human leukocyte antigen DQ 2.2/2.5/8 genotyping was performed.

RESULTS

Thirty-four patients had TGA-IgA titres >10× upper limit of normal (ULN; 36%); all had villous atrophy with positive EMA and DQ 2.2/2.5/8. The sensitivity and specificity of a TGA-IgA titre >10× ULN in correctly diagnosing CD was 100%. There was a significant positive correlation between the anti-TGA-IgA titre and the severity of enteropathy (P < 0.001). There was no significant difference in the TGA-IgA titre between the asymptomatic and symptomatic CD patients.

CONCLUSIONS

Our results provide evidence that a TGA-IgA titre >10× ULN correlates with villous atrophy in CD patients detected by mass screening.

Adherence to dietary treatment and clinical factors associated with anti-transglutaminase antibodies in celiac disease during the follow-up

INTRODUCTION

In clinical practice, celiac disease (CD) is monitored through anti-transglutaminase (TGA-IgA) antibody levels. The normalization of serum levels in successive periodic measurements indicates good response and adherence to dietary treatment.

OBJECTIVES

To evaluate the factors associated with the evolution of TGA-IgA antibodies and their association with dietary non-compliance and diseases related to CD.

METHODS

This prospective observational study was carried out in 254 participants, who were recruited from patients from a hospital in southern Spain. Information about sex, age, serological test results, HLA DQ2/DQ8 haplotypes, mucosal atrophy, gastrointestinal and extra-intestinal symptoms, as well as diagnosis of diseases related to CD, was collected.

RESULTS

Clinical manifestations, such as diarrhoea, abdominal pain and weight loss, showed differences according to sex and age. Children under 18 years of age presented a degree of total or severe atrophy of the intestinal villi. TGA-IgA antibodies concentrations were directly associated with the number of digestive disorders manifested by the patient and the record of dietary non-compliance and inversely related to the number of extra-digestive disorders.

CONCLUSIONS

Adolescents between 12 and 18 years old were the least monitored as well as the group with more extra-intestinal symptoms reported. Therefore, it is necessary to develop strategies in clinical practice aimed at this population group and continuous monitoring should be implemented to improve life quality and reduce complications that may arise in the long term.

Association of Anti-tissue Transglutaminase Antibody Titers and Duodenal Biopsy Findings in Pediatric Patients of Celiac Disease

Aims & Objectives

To ascertain the association of serum anti-tissue transglutaminase (anti-tTG) antibody titers with the severity of duodenal mucosal damage on histology andto predict a possible cut-off value of anti-tTG antibody titers for the diagnosis of Celiac disease. Marsh grading greater than two in conjunction with clinical assessment, which may help avert an invasive endoscopic procedure, especially in medically unfit children.

Materials & Methods

A retrospective study was designed wherein demographic and laboratory data of children aged less than 12 years with raised anti-tTG antibody titers with available histopathology of duodenal biopsies were extracted from the hospital medical records and reviewed.

Results

A total of 134 children were included in the study, which showed female preponderance. Histopathological changes, characteristic of Celiac disease, were observed in 116 cases; seven among the rest showed evidence of Giardiasis, and 13 could be considered potential Celiac. Of the 116 patients, 1.7% belonged to Marsh grade I, 5.2% grade II and 8.6%, 26.7%, and 57.7% to grade IIIA, IIIB, and IIIC, respectively. A significant association was found between anti-tTG antibody titers and Marsh grading. The cut-off value of anti-tTG antibody titer levels for diagnosing Celiac disease using receiver operating characteristics (ROC) curve in predicting Marsh greater than two at histology was observed to be 84.6 U/ml with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 91.7%, 68.4%, 94.2%, and 59%, respectively.

Conclusion

An anti-tTG antibody titer greater than 10 times the upper limit of normal (≥84 U/ml) is significantly associated with Marsh grade greater than two. Standard stool microscopy may be used as a simple tool in the workup of all children with raised anti-tTG antibody levels to rule out Giardiasis to avert unnecessary endoscopic evaluation for Celiac disease in such cases.

Epitope mapping of anti-amelogenin IgG in untreated celiac children

Children with untreated celiac disease (CeD) may develop enamel defects, and children with severe CeD have significantly increased levels of IgG to amelogenin, which may interfere with normal amelogenesis depending on which epitope(s) they bind. Children with untreated CeD (n = 42), for whom CeD had been confirmed either by biopsy (n = 17, cohort 1) or by the presence of particularly high serum levels of anti-transglutaminase 2 (TG2) IgA (n = 25, cohort 2), were selected from 146 children with CeD, and 10 controls were selected from 34 children who did not have CeD. Samples from these 52 children were used for detailed IgG anti-amelogenin, X isoform (AMELX) epitope mapping using 31 overlapping, 10-22mer peptides in ELISA. Although sera from both groups showed reactivity to peptides containing sequences from the N and C terminus of AMELX, sera from children with CeD reacted more strongly to peptides from the central region (amino acids 75-150) containing both a binding site for transforming growth factor-β (TGF-β), as well as the enzymatic cleavage sites for matrix metalloproteinase-20 and for kallikrein-4. Antigen-specific extraction revealed that only IgG to the central region cross-reacted to gliadin. Thus, cross-reactive anti-gliadin/amelogenin IgG may affect normal amelogenesis by interfering with enzymatic degradation, proper folding, and/or TGF-β signaling in children with untreated CeD.

Correlation of TTG IgA Level with Small Intestinal Histopathological Changes for Celiac Disease among Adult Saudi Patients

Background and objectives

According to recent guidelines, a diagnosis of celiac disease (CD) can be made without a biopsy, especially in children. There are no enough studies despite high prevalence and differences in genetic, race, and cultures. Therefore, we examined the correlation between tissue transglutaminase (TTG) and duodenal biopsy changes in our region because we are identical and different from others in culture, environment, and habits, and the correlation is same as that in different regions.

Methods

A retrospective cohort study at the Ministry of National Guard Health Affaires (NGHA) health care facilities that are distributed throughout kingdom of Saudi Arabia from April 19, 2015, till March 29, 2018. This study used the BESTCARE system that includes data from all NGHA facilities; data from 513 patients with CD were collected. All patients diagnosed with celiac disease aged 15 years or more, confirmed by improvement on gluten-free diet (GFD), and were not on GFD before endoscopy or serology test or both of them were included in the study, and the TTG IgA level was measured at the same time or within 2–3 months of biopsy date. The exclusion criteria were negative duodenal biopsy, which is less than 2; patients with negative biopsy and negative serology; patients who were on GFD before testing, and any patients known to have immunity diseases or illness causing mucosal changes. The TTG IgA level was measured in IU/ mL and was labeled as negative (<20 IU/mL) and positive (≥ 20 IU/mL) based on the cutoff value. However, Intestinal biopsy findings were identified as Marsh classification groups.

Results

One hundred thirty-four patients who met the inclusion criteria were included in the study. Median age of our sample was 24 years (16–37 years). Among these, 99 (73.88%) were female patients, whereas male patients were only 35 (26.12%). Histopathologic investigation of intestinal biopsy were Marsh 0 group was 16 cases (11.9%), Marsh 1 group was 8 cases (6%), Marsh 2 group was 4 cases (3%), Marsh 3a group was 32 cases (23.9%), Marsh 3b group was 64 cases (47.8%), and Marsh 3c group was 10 cases (7.5%). The TTG IgA antibody serology groups were <20 IU/mL in 13 cases (9.7%) and ≥20 IU/mL in 121 cases (90.3%). Among all patients with CD who had negative biopsy (Marsh 0 group), 16 (100%) of them had positive TTG IgA antibody. However, among patients with Marsh 1 group biopsy, 5 (62.5%) cases had negative TTG IgA antibody compared with 3 (37.5%) positive cases. Of the four cases (100%) with Marsh 2 group, all of them had positive TTG IgA antibody. However, in Marsh 3a group biopsy, 3 (9.4%) cases had negative TTG IgA antibody compared with 29 (90.6%) cases with positive TTG IgA antibody. Furthermore, among the patients with Marsh 3b group biopsy, 5 (7.8%) had negative antibody and 59 (92.2%) had positive serology. Of all biopsies of Marsh 3c group, 10 (100 %) had positive TTG IgA antibody.

Conclusions

In perspective of high prevalence of CD in KSA, even more than western countries, we can pretend that positive TTG antibody tests can be applied for the diagnosis of CD without biopsy, particularly in symptomatic patients along with high titer, that is, 5–10 times the upper limit of normal (ULN). However, to validate it further, we need larger prospective studies in which duodenal biopsies should be taken according to recommended protocol and should be interpreted by experienced pathologist. Furthermore, biopsy is still needed in patients who do not show clinical improvement on a gluten-free diet and in cases with mildly or moderately elevated TTG IgA.

Prevalence and diagnostic outcomes of children with duodenal lesions and negative celiac serology

BACKGROUND

Celiac disease diagnostics begin by measuring autoantibodies, which may fail to identify seronegative patients. Duodenal lesion in the absence of antibodies is scarcely studied, especially in children.

AIMS

To investigate the prevalence and diagnostic outcomes of children with seronegative duodenal lesion in two countries with different disease profiles.

METHODS

Medical data, including the results of histology and transglutaminase (tTGab) and endomysium (EmA) antibody measurements were collected from 1172 Finnish and 264 Romanian children with systematic duodenal sampling. Database of 509 Finnish children with celiac disease was examined to identify earlier seronegative patients.

RESULTS

Celiac disease was diagnosed in 307 Finnish and 83 Romanian children in the endoscopy cohorts. No seronegative patients were found among 899 celiac disease patients, although some were only tTGab or EmA positive. Non-celiac duodenal lesion was detected in eight Finnish and 32 Romanian children, their most common diagnoses being inflammatory bowel disease and infections, respectively. Six children with morphological lesion received no diagnosis. None of them developed celiac disease during a follow-up of 3-11 years.

CONCLUSION

Pediatric seronegative celiac disease is exceptional in the era of modern autoantibodies. Other reasons for duodenal lesion should therefore be sought, bearing in mind possible differences across countries.

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.

Management of celiac disease in daily clinical practice

Celiac disease (CD) is the most common autoimmune enteropathy worldwide. In CD, dietary gluten triggers a T cell driven small intestinal inflammation in a subset of genetically predisposed subjects, expressing the HLA DQ2 and/or DQ8 genes on their antigen presenting cells. HLA DQ2/DQ8 can bind gluten peptides after their prior modification by the CD autoantigen, tissue transglutaminase (TG2). This process leads to the activation of gluten reactive T cells, small bowel villous atrophy, crypt hyperplasia and intraepithelial lymphocytosis, the histological hallmarks of CD. The clinical picture of CD is extremely heterogeneous including intestinal (especially diarrhea, abdominal pain, bloating) and extraintestinal (especially associated autoimmune diseases, anemia, osteoporosis) manifestations. The prevalence of CD in most parts of the world is estimated at 1:100-1:150 and its diagnosis is based on the presence of circulating autoantibodies (anti-TG2) and the histological detection of villous atrophy. Treatment is a lifelong gluten free diet but adjunctive therapies are in development. Although CD is a well-characterized disease, it is grossly underdiagnosed, despite the severe consequences of long-term gluten ingestion in CD, such as enhanced autoimmunity, refractory CD and intestinal T cell lymphoma. The aim of the presented review is to provide a clinical guide and to summarize the most recent clinical progress in CD research.

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).

Celiac Disease Diagnosis Without Biopsy: Is a 10× ULN Antitransglutaminase Result Suitable for a Chemiluminescence Method?

OBJECTIVES

2012 European Society of Pediatric Gastroenterology, Hepatology and Nutrition guidelines allow to establish a celiac disease diagnosis without duodenal biopsy in symptomatic pediatric patients with antitissue transglutaminase (anti-tTG) titers >10 times the upper limit of normal. For some years now, new chemiluminescence immunoassays have been made available: it is important to establish the clinical performance of anti-tTG and to determine the cut-off best suited to predict Marsh ≥2 to avoid gastrointestinal endoscopy not only in children, but also in the adult population.

METHODS

A total of 2565 patients performed duodenal biopsy from July 2012 to September 2016; we selected all the patients who had undergone QUANTA Flash anti-tTG immunoglobulin A (IgA) within -3 months of duodenal biopsy and before the start of gluten-free diet. A total of 827 patients fulfilled the criteria for selection.

RESULTS

Using a cut-off of 20 chemiluminescent unit (CU; area under the curve: 0.995), sensitivity, specificity, positive, and negative predictive value were 98.2%, 98.4%, 97.9%, and 98.6%, respectively. For the correlation with Marsh ≥2, in the pediatric population, positive predictive values (PPV) were 92.1%, 99%, and 100% at 200 CU (10×), 560 CU (28×), and 1000 CU (50×), respectively. In the adult population PPV was 94.2%, 98.2%, and 100% at 200 CU (10×), 350 CU (15×), and 400 CU (20×).

CONCLUSIONS

Sensitivity, specificity, positive, and negative predictive value of QUANTA Flash h-tTG IgA were excellent. The cut-off providing an optimized PPV for histological lesions compatible for celiac disease (Marsh ≥2) for the QUANTA Flash h-tTG IgA is 350 CU (15×) in adult and 560 CU (28×) in children.

The serological diagnosis of coeliac disease - a step forward

The development of highly performing serological tests to identify patients with coeliac disease (CD), allowed large scale screening studies to be carried out and the results transformed our understanding of the prevalence of the condition in the general population. The next logical step was to ask whether CD could be reliably diagnosed by these tests without the need for small intestinal biopsies. This was shown to be the case. Studies from Derby, UK, indicated that about half of adult patients can be diagnosed in this way and similar figures have been provided for children. When considering this approach, it is essential that laboratories only use highly performing test kits that they have validated to measure tissue transglutaminase antibodies because all kits do not function to the same high standard. There remains a place for biopsy when criteria for serological diagnosis are not met, if the diagnosis of CD is strongly suspected but serological tests are negative or in patients not showing the expected responses to gluten free diet or otherwise causing concern, when not only small bowel biopsy will be indicated but also other investigations. Those with refractory CD should not be compromised by this diagnostic strategy. As serological tests become more refined and information accumulates, it is likely that this mode of diagnosis will gather momentum for the benefit of patients and carers. This brief review looks at the evidence for making the diagnosis of CD in some cases by serological tests alone.

Coeliac disease: to biopsy or not?

Coeliac disease is increasingly recognized as a global problem in both children and adults. Traditionally, the findings of characteristic changes of villous atrophy and increased intraepithelial lymphocytosis identified in duodenal biopsy samples taken during upper gastrointestinal endoscopy have been required for diagnosis. Although biopsies remain advised as necessary for the diagnosis of coeliac disease in adults, European guidelines for children provide a biopsy-sparing diagnostic pathway. This approach has been enabled by the high specificity and sensitivity of serological testing. However, these guidelines are not universally accepted. In this Perspective, we discuss the pros and cons of a biopsy-avoiding pathway for the diagnosis of coeliac disease, especially in this current era of the call for more biopsies, even from the duodenal bulb, in the diagnosis of coeliac disease. In addition, a contrast between paediatric and adult guidelines is presented.

Celiac Disease in South Jordan

PURPOSE

Celiac disease, an autoimmune enteropathy triggered by exposure to gluten, is not uncommon in South Jordan. However, its prevalence is underestimated due to lack of physician awareness of the diversity of disease presentation. The clinical spectrum includes classic gastrointestinal manifestations, as well as rickets, iron-deficiency anemia, short stature, elevated liver enzymes, and edema. Our goal was to evaluate celiac disease presentation in clinically diagnosed children.

METHODS

Retrospective study included all children diagnosed with celiac disease between September 2009 and September 2015. Hospital charts were reviewed. Demographic data, clinical characteristics, and follow-up were recorded.

RESULTS

Thirty-five children were diagnosed with celiac disease during the study period. Mean age±standard deviation was 6.7±3.8 years (range, 2.0-14 years). There were 17 (48.6%) female patients. The average duration between onset of symptoms and diagnosis was 16.3±18.7 months. Fifteen (42.9%) patients presented with classic malabsorption symptoms, whereas 7 (20.0%) patients presented with short stature. Positive tissue transglutaminase antibodies (tTg)-immunoglobulin A (IgA) was seen in 34 (97.1%) patients. The one patient with negative tTg-IgA had IgA deficiency. Although tTG-IgA values were not available for objective documentation of compliance, clinical data (resolution of presenting abnormalities and growth improvement) assured acceptable compliance in 22 (62.9%) patients.

CONCLUSION

CD in children may present with diverse picture. Although of the small number, the non-classical presentations are not uncommon in our rural community. Gluten-free diet is the main strategy for treatment and associated with usually correction of laboratory abnormalities and improvement of growth.

Coeliac disease and gastrointestinal symptom screening in adult first-degree relatives

BACKGROUND AND AIM

The first-degree relatives (FDRs) of patients with coeliac disease are the main risk group for disease development. The study aims to evaluate the screening strategy in FDRs with negative coeliac serology based on human leukocyte antigen (HLA) genotyping, followed by duodenal biopsy, and to analyze the prevalence of gastrointestinal symptoms and the influence of gluten intake.

METHODS

Adult FDRs with negative coeliac serology were invited to participate (n = 205), and a total of 139 completed the study protocol. HLA genotyping, transglutaminase antibody assessment, and duodenal biopsy were performed. Symptomatology was assessed using questionnaires during the various phases of dietary modification (baseline diet, gluten-free diet, and gluten overload).

RESULTS

The study included 139 participants (mean age, 42 years; 53.2% women). HLA-DQ2/8 was positive in 78.4% of the participants (homozygous, 15.1%; heterozygous, 63.3%). Histopathological alterations were noted in 37.1% of participants who underwent duodenal biopsy (Marsh I, 32.7%; Marsh IIIa, 4.4%). At baseline, symptoms were observed in 45.7% of the participants, and the proportion decreased to 24.5% after the gluten-free diet (P < 0.001). Symptoms were not associated with the presence of histological alterations or genetic risk. However, younger age (odds ratio [OR] = 0.91), female sex (OR = 2.9), and the presence of autoimmune disorders (OR = 2.8) were independently associated with a significant symptom response to the gluten-free diet.

CONCLUSIONS

Duodenal lymphocytosis and atrophy are frequently noted in FDRs, despite negative serological markers. In addition, gastrointestinal symptoms are commonly present and associated with gluten intake regardless of the histological pathology.

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.

Celiac disease: from etiological factors to evolving diagnostic approaches

Celiac disease has advanced from a medical rarity to a highly prevalent disorder. Patients with the disease show varying degrees of chronic inflammation within the small intestine due to an aberrant immune response to the digestion of gliadin found in wheat. As a result, cytokines and antibodies are produced in celiac patients that can be used as specific biomarkers for developing diagnostic tests. This review paper describes celiac disease in terms of its etiological cause, pathological effects, current diagnostic tests based on mucosal biopsy, and the genetic basis for the disease. In addition, it discusses the use of gliadin-induced cytokines, antibodies and autoantibodies as a diagnostic tool for celiac disease. Despite good initial results in terms of sensitivity and specificity, when these immunological tests were used on a large scale, even in combination with genetic testing, the results showed lower predictive value. This review addresses that issue and ends with an outlook on future work required to develop diagnostic tests with greater accuracy in predicting celiac disease in the general public, thus avoiding the need for endoscopy and mucosal biopsy.

Validation of Antibody-Based Strategies for Diagnosis of Pediatric Celiac Disease Without Biopsy

BACKGROUND & AIMS

A diagnosis of celiac disease is made based on clinical, genetic, serologic, and duodenal morphology features. Recent pediatric guidelines, based largely on retrospective data, propose omitting biopsy analysis for patients with concentrations of IgA against tissue transglutaminase (IgA-TTG) >10-fold the upper limit of normal (ULN) and if further criteria are met. A retrospective study concluded that measurements of IgA-TTG and total IgA, or IgA-TTG and IgG against deamidated gliadin (IgG-DGL) could identify patients with and without celiac disease. Patients were assigned to categories of no celiac disease, celiac disease, or biopsy required, based entirely on antibody assays. We aimed to validate the positive and negative predictive values (PPV and NPV) of these diagnostic procedures.

METHODS

We performed a prospective study of 898 children undergoing duodenal biopsy analysis to confirm or rule out celiac disease at 13 centers in Europe. We compared findings from serologic analysis with findings from biopsy analyses, follow-up data, and diagnoses made by the pediatric gastroenterologists (celiac disease, no celiac disease, or no final diagnosis). Assays to measure IgA-TTG, IgG-DGL, and endomysium antibodies were performed by blinded researchers, and tissue sections were analyzed by local and blinded reference pathologists. We validated 2 procedures for diagnosis: total-IgA and IgA-TTG (the TTG-IgA procedure), as well as IgG-DGL with IgA-TTG (TTG-DGL procedure). Patients were assigned to categories of no celiac disease if all assays found antibody concentrations <1-fold the ULN, or celiac disease if at least 1 assay measured antibody concentrations >10-fold the ULN. All other cases were considered to require biopsy analysis. ULN values were calculated using the cutoff levels suggested by the test kit manufacturers. HLA typing was performed for 449 participants. We used models that considered how specificity values change with prevalence to extrapolate the PPV and NPV to populations with lower prevalence of celiac disease.

RESULTS

Of the participants, 592 were found to have celiac disease, 345 were found not to have celiac disease, and 24 had no final diagnosis. The TTG-IgA procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.934; the TTG-DGL procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.958. Based on our extrapolation model, we estimated that the PPV and NPV would remain >0.95 even at a disease prevalence as low as 4%. Tests for endomysium antibodies and HLA type did not increase the PPV of samples with levels of IgA-TTG ≥10-fold the ULN. Notably, 4.2% of pathologists disagreed in their analyses of duodenal morphology-a rate comparable to the error rate for serologic assays.

CONCLUSIONS

In a prospective study, we validated the TTG-IgA procedure and the TTG-DGL procedure in identification of pediatric patients with or without celiac disease, without biopsy. German Clinical Trials Registry no.: DRKS00003854.

Correlation of Tissue Transglutaminase with Modified Marsh Grading in Celiac Disease: A Prospective Cohort Study

OBJECTIVE

To find out correlation between serum anti-tissue transglutaminase immunoglobulin-A (tTGA) levels and Marsh grading on duodenal histopathology in Celiac disease (CD).

METHODS

In a prospective cohort study, a total of 52 symptomatic patients between age group of 2-18 y were enroled. All enroled patients were subjected to upper GI endoscopy by an experienced endoscopist. Two biopsies each from the bulb (D1) and second part (D2) of the duodenum were taken and Marsh grading was performed by a single experienced pathologist. Serum tTGA levels were also performed to find out correlation between serum tTGA levels and Marsh grading.

RESULTS

The mean age of the patients was 8.21 ± 3.45 y (Range: 2-16 y). Anemia was the most common non-gastrointestinal (GI) sign and was present in 73% of the cases. However the authors could not find out any significant association between Marsh grading and hemoglobin levels (r = 0.32, p > 0.05). Serum tTGA levels were found to be positively correlated with Marsh grading (Spearmen correlation coefficient ρ = 0.74, p 0.000). Significant differences were found in tTGA levels between different Marsh gradings (ANOVA test) (p 0.000). Receiver-operator curve (ROC) analysis cut-off value of serum tTGA for predicting villous atrophy was 178.8 (nine times of cut-off value) with sensitivity of 100% and specificity of 85.7%.

CONCLUSIONS

Serum tTGA levels can be used to predict villous atrophy and biopsy may be avoided in strongly suspected cases with more than 9 times of cut-offs.

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.

Optimizing the diagnosis of celiac disease

PURPOSE OF REVIEW

The diagnostic approach in celiac disease is continuously evolving as our understanding of its pathophysiology improves. This review aims to provide a summary of contemporary work that supports optimization of the diagnosis of this common yet underdiagnosed condition.

RECENT FINDINGS

The recently updated National Institute of Clinical Excellence and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines and the contentious biopsy-free diagnostic approach will be discussed. We will review the evidence advocating optimal biopsy techniques such as single bite biopsy and controversial bulb biopsy sampling to increase diagnostic yield. Recent data providing phenotypical characterization and clinical outcomes of celiac subtypes such as potential celiac disease, seronegative celiac disease and ultrashort celiac disease will be covered. We will present emerging evidence on novel case finding strategies with point of care tests. Promising novel markers for celiac disease such as serum intestinal fatty acid binding protein and in-vitro gluten challenge will be included.

SUMMARY

Recent work has demonstrated the clinical significance of the celiac disease subtypes, emphasizing the importance of careful diagnosis and recognition. There is a move toward a less invasive and perhaps more cost-effective diagnostic approach in celiac disease, but duodenal biopsy remains the gold standard at present for all adults and the majority of pediatric patients.

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.

Pattern of thyroid, celiac, and anti-cyclic citrullinated peptide autoantibodies coexistence with type 1 diabetes mellitus in patients from Southwestern Saudi Arabia

Objectives:

To investigate the seroprevalence of coexisting autoantibodies among type 1 diabetes mellitus (T1DM) patients, and to look for possible correlations with age at diagnosis, diabetes duration, and glycemic control.

Methods:

This is a cross-sectional study conducted at Aseer Central Hospital, Abha, Kingdom of Saudi Arabia from March 2013 to June 2014. A total of 202 T1DM patients were screened for serum anti-thyroglobulin (TG), anti-thyroid peroxidase (TPO), anti-tissue transglutaminase (aTTG), anti-endomysial (EMA), and anti-cyclic citrullinated peptide (anti-CCP) antibodies along with glycated hemoglobin, and biometric data.

Results:

From the 202 T1DM patients (96 males, and 106 females) (mean age: 11.3 years), 33 (16.3%) were positive for thyroid autoantibodies. Specifically, 19 (9.4%) were positive for TG and 25 (12.8%) were positive for TPO, and 11 were double positive. There were 21 (10.4%) patients that showed a double positive for both aTTG-IgA and EMA, and only one case of T1DM was positive for anti-CCP. No significant correlations were noticed between the presence of autoantibodies and the age at diagnosis, diabetes duration, body mass index, and glycemic control.

Conclusion:

The prevalence of thyroid and celiac disease autoantibodies is high among T1DM patients, while anti-CCP remains low and might be weakly associated with T1DM in the southwestern region of Saudi Arabia. No significant correlation between the age at T1DM diagnosis, duration, and glycemic control, and the presence of autoantibodies was found.

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.

Identification of a serum transglutaminase threshold value for the noninvasive diagnosis of symptomatic adult celiac disease patients: a retrospective study

BACKGROUND

A celiac disease (CD) diagnosis is based on duodenal histology, with the exception of children showing anti-tissue transglutaminase (anti-tTG) serum levels exceeding ten times the cut-off. Our aim was to reproduce this simplified approach in adults, identifying an anti-tTG threshold value useful to diagnose CD without endoscopic procedures.

METHODS

A total of 671 adult CD patients were subjected to blood sampling to determine anti-tTG serum levels, as well as to endoscopy with biopsy to perform duodenal histology. The anti-tTG serum levels/cut-off ratio was compared with the degree of duodenal lesions.

RESULTS

Anti-tTG serum levels/cut-off ratio determined in patients with type IIIc was significantly higher than that measured in patients with type IIIb (p < 0.001), IIIa (p < 0.001), II (p < 0.05) and 0 (p < 0.001) of Marsh-Oberhuber histological classification. A significant correlation (r = 0.297, p < 0.0001) was found between the anti-tTG serum levels/cut-off ratio and the degree of duodenal lesions. The anti-tTG serum levels/cut-off ratio was classified as an accurate parameter (AUC = 0.715, p < 0.0001), with the best diagnostic performance obtained considering the threshold value >3.6 (sensitivity = 76.8 %, PPV = 97.2 %).

CONCLUSIONS

The anti-tTG serum levels/cut-off ratio correlates with the degree of duodenal lesions and, if used with the threshold value >3.6, could avoid endoscopy with biopsy in about 75 % of seropositive adults waiting for CD diagnosis. However, since this procedure could also imply CD diagnosis in almost 3 % of seropositive patients with normal villous architecture, a consensus opinion is needed to suggest its use in the diagnosis of adult CD.

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.

Elderly Onset Celiac Disease: A Narrative Review

Celiac sprue is a chronic disease, which usually occurs in children and young adults. However, it can develop in any age group, and the prevalence is increasing even in the elderly population. The atypical patterns of clinical presentation in this age group sometimes can cause a delay in diagnosis. Given the lower sensitivity and specificity of serological tests in the aged population, clinical suspect often arises in the presence of complications (autoimmune disorders, fractures, and finally, malignancy) and must be supported by endoscopic and imaging tools. In this review, we highlight the incidence and prevalence of celiac disease in the elderly, the patterns of clinical presentation, diagnosis, and the most frequent complications, with the aim of increasing awareness and reducing the diagnostic delay of celiac disease even in the elderly population.

Combining antibody tests and taking into account antibody levels improves serologic diagnosis of celiac disease

BACKGROUND

The European Society for Pediatric Gastroenterology and Nutrition states that if IgA anti-tissue transglutaminase (tTG) exceeds 10 times the upper limit of normal (ULN), there is the possibility to diagnose celiac disease (CD) without duodenal biopsy, if supported by anti-endomysium testing and human leukocyte antigen (HLA) typing. We aimed to evaluate whether combining IgA tTG and IgG anti-deamidated gliadin peptide (DGP) antibody testing and taking into account the antibody levels improves clinical interpretation.

METHODS

We calculated likelihood ratios for various test result combinations using data obtained from newly diagnosed CD patients (n=156) [13 children <2 years, 45 children between 2 and 16 years, and 98 adults (>16 years)] and 974 disease controls. All patients and controls underwent duodenal biopsy. IgA anti-tTG and IgG anti-DGP assays were from Thermo Fisher and Inova.

RESULTS

Likelihood ratios for CD markedly increased with double positivity and increasing antibody levels of IgA anti-tTG and IgG anti-DGP. Patients with double positivity and high antibody levels (>3 times, >10 times ULN) had a high probability for having CD (likelihood ratio ≥649 for >3 times ULN and ∞ for >10 times ULN). The fraction of CD patients with double positivity and high antibody levels was 59%-67% (depending on the assay) for >3 ULN and 33%-36% (depending on the assay) for >10 ULN, respectively. This fraction was significantly higher in children with CD than in adults.

CONCLUSIONS

Combining IgG anti-DGP with IgA anti-tTG and defining thresholds for antibody levels improves the serologic diagnosis of CD.

Evaluation of the Correlation Between tTG-IgA Titer and Duodenal Biopsy Findings in Children With Suspected Celiac Disease

Background:

Celiac disease is an immune-mediated inflammation of the small intestine caused by sensitivity to dietary gluten in genetically sensitive individuals.

Objectives:

In this study, we aimed to evaluate the predictive value of tissue transglutaminase (tTG) antibodies for the diagnosis of celiac disease in a pediatric population in order to determine if duodenal biopsy can be avoided.

Patients and Methods:

The subjects were selected among individuals with probable celiac disease, referring to a gastrointestinal clinic. After physical examinations and performing tissue transglutaminase-immunoglobulin A (tTG-IgA) tests, upper endoscopy was performed if serological titer was higher than 18 IU/mL. Therapy started according to pathologic results.

Results:

The sample size was calculated to be 121 subjects (69 female and 52 male subjects); the average age of subjects was 8.4 years. A significant association was found between serological titer and pathologic results; in other words, subjects with high serological titer had more positive pathologic results for celiac disease, compared to others (P < 0.001). Maximum sensitivity (65%) and specificity (65.4%) were achieved at a serological titer of 81.95 IU/ml; the calculated accuracy was lower in comparison with other studies. As the results indicated, lower antibody titer was observed in patients with failure to gain weight and higher antibody titer was reported in diabetic patients.

Conclusions:

As the results indicated, a single serological test (tTg-IgA test) was not sufficient for avoiding intestinal biopsy.

Age-related differences in celiac disease: Specific characteristics of adult presentation

Celiac disease may appear both in early childhood and in elderly subjects. Current knowledge of the disease has revealed some differences associated to the age of presentation. Furthermore, monitoring and prognosis of celiac subjects can vary depending on the pediatric or adult stage. The main objective of this review is to provide guidance for the adult diagnostic and follow-up processes, which must be tailored specifically for adults and be different from pediatric patients.

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.

Adaptive diagnosis of coeliac disease

Coeliac disease has for a long time simply been regarded as a gluten-dependent enteropathy and a duodenal biopsy was required in all patients for the diagnosis. It is now accepted that autoimmunity against transglutaminase 2 is an earlier, more universal and more specific feature of coeliac disease than histologic lesions. Moreover, high serum levels of combined anti-transglutaminase 2 and anti-endomysium antibody positivity have excellent predictive value for the presence of enteropathy with villous atrophy. This makes the histology evaluation of the gut no longer necessary in well defined symptomatic paediatric patients with compatible HLA-DQ2 and/or DQ8 background. The biopsy-sparing diagnostic route is not yet recommended by gastroenterologists for adults, and certain clinical circumstances (immunodeficiency conditions, extraintestinal manifestations, type-1 diabetes mellitus, age less than 2 years) may require modified diagnostic approaches. Coeliac patients with preserved duodenal villous structure do exist and these need a more extended evaluation by immunologic and molecular biology tools.

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.

Prevalence estimation of celiac disease in the general adult population of Latvia using serology and HLA genotyping

BACKGROUND

Prevalence estimates for celiac disease (CD) depend on the method used. The role of deamidated gliadin peptide (DGP) and genetic testing in epidemiological studies and diagnostic settings of celiac disease (CD) has still to be established.

OBJECTIVES

The objective of this article is to assess the prevalence of CD in Latvia by combining serological tests with DQ2.5/DQ8 testing.

METHODS

A total of 1444 adults from a randomly selected cross-sectional general population sample were tested by ELISA for tTG IgA, DGP IgA and IgG antibodies (QUANTA Lite®, Inova Diagnostics Inc). Samples with tTG IgA ≥20U were tested for EMA IgA by indirect immunofluorescence assay, and all specimens with tTG IgA ≥15U were tested by QUANTA-Flash® chemiluminescent assays (CIA) (Inova Diagnostics Inc) for tTG IgA, DGP IgA and IgG. DQ2.5/8 was detected in individuals with any positive ELISA test and a subgroup of controls.

RESULTS

Forty-three individuals (2.98%; 95% CI: 2.10-3.86%) tested positive by at least one ELISA test; 41.86% of the serology-positive individuals (any test above the cutoff) were DQ positive. Six individuals (0.42%; 95% CI: 0.09-0.75%) were triple ELISA positive, and DQ2.5 or DQ8 was positive in all; 0.35% (95% CI: 0.05-0.65%) were tTG IgA and EMA positive. Two tTG IgA-negative cases were both DGP IgG and IgA positive, both being DQ positive; including them in the "serology-positive" group would increase the prevalence to 0.49% (95% CI: 0.13-0.85%). CIA tests revealed 2 tTG IgA-positive and EMA-negative cases with a positive genotype. DQ2.5 or DQ8 genotype was positive in 28.6% of the serology-negative population.

CONCLUSIONS

Estimates of the prevalence of CD in Latvia based on the serogenetic testing approach range from 0.35% to 0.49% depending on the criteria used. There is a rationale for combining serological tests and DQ2.5/8 genotyping.

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.

Celiac Disease: Diagnosis

Historically the diagnosis of celiac disease has relied upon clinical, serological, and histological evidence. In recent years the use of sensitive serological methods has meant an increase in the diagnosis of celiac disease. The heterogeneous nature of the disorder presents a challenge in the study and diagnosis of the disease with patients varying from subclinical or latent disease to patients with overt symptoms. Furthermore the related gluten-sensitive disease dermatitis herpetiformis, while distinct in some respects, shares clinical and serological features with celiac disease. Here we summarize current best practice for the diagnosis of celiac disease and briefly discuss newer approaches. The advent of next-generation assays for diagnosis and newer clinical protocols may result in more sensitive screening and ultimately the possible replacement of the intestinal biopsy as the gold standard for celiac disease diagnosis.

The presence of anti-endomysial antibodies and the level of anti-tissue transglutaminases can be used to diagnose adult coeliac disease without duodenal biopsy

BACKGROUND

The new ESPGHAN guidelines for diagnosis of paediatric coeliac disease suggest to avoid biopsy in genetically pre-disposed and symptomatic individuals with positive anti-endomysial antibodies (EMA) and anti-tissue transglutaminases (a-tTG). However, duodenal biopsy remains the gold standard in adult coeliac disease.

AIMS

To establish the cut-off values of a-tTG, which would: predict the presence of duodenal histology (Marsh ≥2) diagnostic for coeliac disease; and predict the presence of villous atrophy (Marsh 3) in adults.

METHODS

We performed an observational prospective study including all consecutive adult patients with suspected coeliac disease. All subjects were tested for EMA and a-tTG. Coeliac disease diagnosis was made in presence of Marsh ≥2, a-tTG >7 U/mL and positive EMA. A ROC curve was constructed to establish the best specificity cut-off of a-tTG levels, which would predict the presence of Marsh ≥2 and Marsh 3 at histology.

RESULTS

The study included 310 patients with positive antibodies. Histology showed Marsh 1 in 8.7%, Marsh 2 in 3.5%, Marsh 3 in 87.7%. The best cut-off value of a-tTG for predicting Marsh ≥2 was 45 U/mL (sensitivity 70%; specificity 100%; PPV 100%; NPV 24.1%); the best cut-off for predicting villous atrophy was 62.4 U/mL (sensitivity 69%, specificity 100%; PPV 100%; NPV 31%).

CONCLUSIONS

The diagnosis of coeliac disease can be reached without histology in adult patients with positive EMA and a-tTG levels >45 U/mL. An a-tTG level >62.4 was diagnostic for villous atrophy. These results could contribute to improving the diagnosis of coeliac disease by allowing for a significant reduction in diagnosis-related costs.