ANTI HUMAN TISSUE TRANSGLUTAMINASE (TTG) ANTIBODY (IGA)

The Anti-Human Tissue Transglutaminase (tTG) Antibody (IgA) Test is a highly sensitive and specific blood test used to detect Immunoglobulin A (IgA) antibodies against tissue transglutaminase (tTG), an enzyme found in the body's tissues. It is considered the preferred first-line serological test for screening and diagnosing celiac disease.

Celiac disease is an autoimmune disorder in which the ingestion of gluten—a protein found in wheat, barley, and rye—triggers an immune response that damages the lining of the small intestine. This damage affects nutrient absorption and may lead to gastrointestinal symptoms, nutritional deficiencies, and long-term health complications if left untreated.

When individuals with celiac disease consume gluten, the immune system produces antibodies against tissue transglutaminase. Measuring Anti-tTG IgA antibodies helps identify this autoimmune response. Due to its excellent diagnostic accuracy, the Anti-tTG IgA test is routinely recommended by gastroenterology guidelines as the primary blood test for celiac disease.

The test is often performed along with Total Serum IgA to rule out IgA deficiency, and additional tests such as Endomysial Antibody (EMA) or Deamidated Gliadin Peptide (DGP) antibodies may be recommended when necessary.

Benefits of the Test

• Highly sensitive and specific for celiac disease
• Preferred first-line screening test for celiac disease
• Detects autoimmune response to gluten
• Helps diagnose gluten-sensitive enteropathy
• Supports early diagnosis before complications develop
• Assists in monitoring response to a gluten-free diet
• Requires only a peripheral blood sample

Why Doctors Recommend This Test

Doctors may recommend this test for individuals with:

• Chronic diarrhea
• Persistent abdominal pain or bloating
• Unexplained weight loss
• Iron deficiency anemia
• Chronic fatigue
• Nutritional deficiencies
• Osteoporosis at a young age
• Recurrent mouth ulcers
• Family history of celiac disease
• Type 1 diabetes or autoimmune thyroid disease
• Suspected gluten-related disorders

Preparation Before Test

Sample Required

• Peripheral venous blood sample (Serum)

Preparation Guidelines

• No fasting is required.
• Continue eating gluten-containing foods before the test unless your doctor advises otherwise. Avoiding gluten before testing may lower antibody levels and produce false-negative results.
• Inform your physician about any autoimmune conditions or current medications.
• Follow laboratory instructions before sample collection.

Reporting Time

Results are generally available within 3–7 working days, depending on laboratory processing.

Who Should Take This Test?

This test is recommended for:

• Individuals with symptoms suggestive of celiac disease
• Children and adults with chronic digestive complaints
• Patients with unexplained anemia or nutritional deficiencies
• Individuals with a family history of celiac disease
• Patients with autoimmune disorders associated with celiac disease
• Individuals with unexplained weight loss or chronic diarrhea
• Patients being evaluated before starting a gluten-free diet

Clinical Significance

Elevated Anti-Human Tissue Transglutaminase (tTG) IgA antibodies may indicate:

• Celiac Disease
• Gluten-Sensitive Enteropathy
• Autoimmune Small Intestinal Disease
• Gluten-Related Autoimmune Disorders

Common symptoms that may prompt testing include:

• Chronic diarrhea
• Abdominal bloating
• Abdominal pain
• Excessive gas
• Weight loss
• Fatigue
• Iron deficiency anemia
• Poor growth in children
• Recurrent mouth ulcers
• Nutrient deficiencies

A positive Anti-tTG IgA result strongly supports the diagnosis of celiac disease but should be interpreted alongside clinical findings, total serum IgA levels, Endomysial Antibody (EMA) results, Deamidated Gliadin Peptide (DGP) antibody tests, and, when indicated, a small intestinal biopsy.