Anti-Tissue Transglutaminase IgA Antibodies

Study Overview
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Brief Summary
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Celiac disease is the most common genetically related food intolerance, worldwide. It is an immune mediated intolerance to gluten (from wheat, barley, or rye) in genetically susceptible individuals .The disease primarily affects the small intestine, where it progressively leads to flattening of the small intestinal mucosa .

Detailed Description
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Within this definition, patients can further be defined as having silent, potential, or latent celiac disease. The term silent celiac disease refers to patients fulfilling the definition above, but presenting no symptoms. Typically, such diagnoses are made by screening asymptomatic individuals, who are at increased risk for celiac disease. The term potential celiac disease describes patients who have specific serum autoantibodies and may or may not have symptoms consistent with celiac disease, but lack evidence of the autoimmune damage to the intestinal mucosa. A final category of celiac patients is represented by the so-called latent celiac disease: individuals with normal mucosal morphology (like the potential) but known to have had a gluten-dependent enteropathy at some point in their life . Malabsorption results from injury to the small intestine with loss of absorptive surface area, reduction of digestive enzymes, and consequential impaired absorption of micronutrients such as fat-soluble vitamins, iron and potentially B12 and folic acid. In addition, the inflammation exacerbates symptoms of malabsorption by causing net secretion of fluid that can result in diarrhea. The failure of absorption of adequate calories leads to weight loss, and the malabsorption results in abdominal pain and bloating . A positive family history is a risk factor for celiac disease. The frequency of celiac disease is higher among first- and second-degree relatives of persons with celiac disease, although prevalence estimates range from 5 to 20 percent . Frequency of celiac disease is also higher among persons with other autoimmune diseases, such as type 1 diabetes mellitus, inflammatory luminal gastrointestinal disorders, Down syndrome, Turner's syndrome, IgA deficiency, and IgA nephropathy . Gastrointestinal and extra-intestinal manifestations of celiac disease include diarrhea, abdominal pain, abdominal distention, anorexia, vomiting, constipation, failure to thrive, chronic fatigue, anemia, osteoporosis, aphthous stomatitis, elevated liver enzymes, joint/muscle pain, epilepsy, and peripheral neuropathy . Clinical practice guidelines recommend to starting with the serum anti-tissue transglutaminase IgA antibodies (anti-tTG IgA) test as a diagnostic testing for celiac disease. The tTG IgA test is the standard method of testing for celiac disease . Clinical practice in guidelines the United States and Europe recommend intestinal biopsy to confirm the diagnosis of celiac disease (e.g., based on presence of villous atrophy hyperplasia of crypts, and increase of intraepithelial lymphocytes) and to distinguish celiac disease from other disorders affecting the small intestine. Intestinal biopsy may also be performed if clinical suspicion for celiac disease is high but serologic tests are negative . It has been suggested that a combination of serologic tests could be used to establish celiac disease diagnosis as an alternative to biopsy, but it is unclear how frequently celiac disease is diagnosed in the absence of biopsy in clinical practice.

Official Title
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The Diagnostic Performance of Anti-Tissue Transglutaminase IgA Antibodies Serum Level for Detection of Patients With Celiac Disease

Conditions
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Celiac Disease in Children

Intervention / Treatment
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* Diagnostic Test: anti-tissue transglutaminase group
* Diagnostic Test: biopsy group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • patients with symptoms suggestive of celiac disease Exclusion Criteria: •chronic active gastrointestinal disease, i.e., irritable bowel syndrome inflammatory bowel disease .

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| anti-tissue transglutaminase group<br>serum IgA-tissue transglutaminase antibody (tTG) was analyzed in serum using a quantitative automated ELISA method by means of a commercially available detection kit using recombinant human tTG as antigen recommended cut-off by the manufacturer > 8 U/mL). | Diagnostic Test: anti-tissue transglutaminase group<br>* Determination of anti-tissue transglutaminase IgA antibodies serum level.<br>Diagnostic Test: biopsy group<br>* Intestinal biopsy for histopathology study the jejunal histopathological<br>|
| biopsy group<br>upper gastrointestinal endoscopic examination will be done and the jejunal histopathological examinations will be done at the Histopathology Laboratory. The features consistent with CD included: hyperplasia of crypts, atrophy of villous, and increase of intraepithelial lymphocytes.Duodenal samples will be processed using haematoxylin/eosin staining and CD3 immunophenotyping. The number of intra-epithelial lymphocytes (IEL), the architecture of villi, and the inflammatory cell infiltration of the lamina propria will be assessed. Histopathological changes will be classified according to the Marsh-Oberhuber criteria.Lymphocytic enteropathy (Marsh 1 lesion) was defined as 25 or more IEL per 100 epithelial nuclei, and normal villous architecture. | Diagnostic Test: anti-tissue transglutaminase group<br>* Determination of anti-tissue transglutaminase IgA antibodies serum level.<br>Diagnostic Test: biopsy group<br>* Intestinal biopsy for histopathology study the jejunal histopathological<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| measure of Anti- tissue will be performed to calculate the post-test probability of celiac disease. | tTG are regarded as qualitative, i.e., positive or negative.Values of tTG between 2 and 7 U/mL will be considered as doubtful positive, and those of 7 U/mL or more as positive. cut-off of ≥7 U/mL will be used in this study. | within 24 hours |