Tissue transglutaminase test

Overview

The tissue transglutaminase test (often called the tTG test) is a blood test that checks for antibodies your body makes when you have celiac disease. If you have celiac disease, eating gluten (a protein in wheat, barley, and rye) causes your immune system to attack your small intestine. This test looks for a specific antibody called immunoglobulin A (IgA) to tissue transglutaminase, which is a sign of that attack.

This test is commonly ordered when a person has symptoms of celiac disease or has a close relative with the condition. Celiac disease itself affects about 1 in 100 people worldwide, so the test is not rare.

It can affect anyone — adults, children, and older adults. People with certain conditions like type 1 diabetes, thyroid disease, or Down syndrome have a higher risk of celiac disease.

Symptoms

Common symptoms

• Bloating and gas
• Chronic diarrhea or constipation
• Fatigue and low energy
• Unexplained weight loss
• Anemia (low iron levels)
• Bone or joint pain

Symptoms in children

• Failure to grow or gain weight (failure to thrive)
• Irritability and mood changes
• Delayed puberty
• Tooth enamel defects

Symptoms in older adults

• Joint pain and arthritis-like symptoms
• Fatigue and weakness
• Osteoporosis or bone fractures
• Nerve problems like tingling or numbness

Causes

Main causes

• Your healthcare provider orders this test because you have symptoms or risk factors for celiac disease. The test itself does not cause anything — it measures your body's immune response to gluten.
• Celiac disease is an autoimmune condition where eating gluten triggers your immune system to damage your small intestine.

Risk factors

• Family history of celiac disease (a parent, sibling, or child with it)
• Having another autoimmune condition (like type 1 diabetes, autoimmune thyroid disease, or rheumatoid arthritis)
• Genetic factors — certain genes (HLA-DQ2 and HLA-DQ8) make you more likely to develop celiac disease

When to see a doctor

See a doctor urgently if:

• If you have severe abdominal pain or blood in your stool, seek emergency care right away.

Book a routine appointment if:

• If you have ongoing digestive symptoms like bloating, diarrhea, or belly pain that last for weeks.
• If you feel very tired all the time and do not know why.
• If a close family member is diagnosed with celiac disease, even if you have no symptoms.

Diagnosis

The diagnosis starts with a blood test called the tissue transglutaminase (tTG) test. If the test is positive, your doctor will usually recommend a biopsy of your small intestine to confirm. You need to be eating gluten every day for at least 6 weeks before the blood test and biopsy, otherwise the results may not be accurate.

Tests that may be done

• tTG blood test (the main screening test)
• Total IgA test (to check for IgA deficiency, which can affect tTG results)
• Endoscopy with biopsy (a thin, flexible tube with a camera is passed through your mouth into your small intestine to take tiny tissue samples)

What to expect at your appointment

The blood test is quick — a small sample of blood is taken from your arm. You do not need to fast. Your doctor will tell you how to prepare for a biopsy if needed. Results from the blood test usually come back in a few days.

Treatment

If celiac disease is confirmed, the only treatment is a strict gluten-free diet for life. This means avoiding all foods and products that contain wheat, barley, and rye. There is no medication that can cure celiac disease — diet is the key.

Self-care at home

• Work with a dietitian who specializes in celiac disease to learn what foods are safe.
• Read food labels carefully — look for 'gluten-free' certification or check ingredients.
• Avoid cross-contamination by using separate toasters, cutting boards, and utensils for gluten-free foods.
• Join a support group to connect with others who follow a gluten-free diet.

Medical treatments

There are no medications approved to treat celiac disease. Your healthcare provider may prescribe supplements if you have vitamin or mineral deficiencies (like iron, vitamin D, or B12). They will also monitor your bone health and screen for other autoimmune conditions as needed.

When is surgery considered?

Surgery is not a treatment for celiac disease. In very rare cases, if complications like lymphoma occur, surgery may be needed, but this is not common.

Living with this condition

Living with celiac disease means following a gluten-free diet every day. Over time, this becomes second nature. You will learn to plan meals, eat out safely, and check labels. Many people feel much better after starting the diet, with improved energy and fewer symptoms.

Lifestyle tips

• Keep a food diary to track symptoms and identify hidden sources of gluten.
• Tell friends, family, and restaurants about your dietary needs.
• Carry gluten-free snacks when traveling.
• Consider using a gluten-detection app to help choose safe foods.

Diet and exercise

A gluten-free diet can be healthy if you include naturally gluten-free foods like fruits, vegetables, lean meats, fish, eggs, beans, nuts, and gluten-free whole grains (like rice, quinoa, and corn). Exercise is important for overall health — aim for at least 30 minutes of moderate activity most days, but listen to your body, especially if you feel tired.

Mental health and emotional wellbeing

Adjusting to a gluten-free diet can be stressful and emotional at first. You may feel frustrated or isolated. It is normal to miss certain foods or feel anxious about eating out. Talk to your doctor or a counselor if you feel overwhelmed. Many people find that their mood improves as their physical symptoms get better.

Prevention

Celiac disease cannot be prevented. It is an autoimmune condition that you either have or do not have. However, if you are diagnosed early and start a gluten-free diet, you can prevent long-term damage to your small intestine and reduce the risk of complications.

Vaccines

There is no vaccine for celiac disease. It is recommended that people with celiac disease get the pneumococcal and influenza (flu) vaccines as part of routine care, because they may be at higher risk for infections. Ask your doctor which vaccines are right for you.

Screening programmes

Routine screening for celiac disease is not recommended for everyone. However, close family members of someone with celiac disease may be offered testing, even if they have no symptoms. Talk to your doctor if you have a family history.

Complications

If left untreated

• Malnutrition and vitamin deficiencies (iron, calcium, vitamin D, B12, folate)
• Osteoporosis (weak, brittle bones)
• Infertility in women
• Lactose intolerance (because the damaged intestine cannot digest lactose)
• Increased risk of other autoimmune diseases (like type 1 diabetes or thyroid disease)
• In rare cases, intestinal lymphoma (a type of cancer)

Long-term outlook

With early diagnosis and a strict gluten-free diet, most people with celiac disease can lead a full, healthy life. The intestine usually heals, symptoms go away, and the risk of complications drops significantly. It takes time to adjust, but you can feel much better.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.