Antibodies to tissue transglutaminase (anti-tTG)

Why is it needed?

This test is used to diagnose celiac disease– an autoimmune disease in which eating gluten (wheat, rye, and barley protein) causes damage to the lining of the small intestine.

Main objectives of the analysis:
✔ Confirmation of the diagnosis of celiacdisease.
✔ Monitoring compliance with a gluten-free diet.
✔ Screening for people with a family history of celiacdisease.

What is Tissue transglutaminase (tTG)?

An enzymeEnzymes are proteins that accelerate chemical reactions in the body. They ensure the occurrence of metabolic processes such as food digestion, energy release, cell formation, and many others.involved in tissue repair.
In celiac disease, the immune system mistakenly attacks tTG, mistaking it for a threat (due to a reaction with gluten).
In response , antibodies (IgA and IgG)are produced, which are detected in the analysis.

Symptoms of a positive test (celiac disease)

Classic symptoms (in children and adults):

Chronic diarrhea or constipation.
Bloating, abdominal pain.
Weight loss (despite a normal diet).
Steatorrhea (greasy, fetid stools).

Extra-intestinal manifestations:

Anemia (due to iron and folic acid deficiency).
Osteoporosis (calcium malabsorption).
Rash (dermatitis herpetiformis).
Infertility, neurological disorders.

Is there a shortage or excess of tTG?

Transglutaminase deficiency -does not occur, as it is an important enzyme of the body.
Excess tTG – has no clinical significance, only the presence of antibodies to itis important.

TTG Antibody standards

The test is performed in the blood (more often IgA antibodies are determined, less often IgG).

Type of antibody	Norm (U / ml)	Interpretation
IgA anti-tTG	< 15	Negative (normal)
	15–30	Weakly positive (repeated test)
	> 30	Positive (celiac disease is likely)
IgG anti-tTG (for IgA deficiency)	< 15	Standard
	> 15	Suspected celiac disease

Important:

5-10% of people with celiac disease may be deficient in IgA, so IgG is additionally tested.
Gluten should not be excluded before the analysis – this may give a false negative result.

What should I do if I get a positive result?

Consultation with a gastroenterologist.
Endoscopy with biopsy (gold standard of diagnostics).
Complete elimination of gluten (wheat, rye, barley).
Control of antibody levels after 6-12 months (to assess the effectiveness of the diet).

When is the test scheduled?

For symptoms of malabsorption (diarrhea, weight loss).
If relatives have celiac disease.
For autoimmune diseases (type 1 diabetes, autoimmune thyroiditis).
For unexplained anemia or osteoporosis.

Conclusion

TTG antibodies are a key marker of celiac disease.
, The norm: < 15 U / ml (IgA).
A positive result (>30 U/ml) requires a bowel biopsy.
, Treatment: a strict gluten-free diet for life.