ATTA: Antibodies to Thyroglobulin — What They Are and What an Elevation Means

Many people are sure that any abbreviation with "TG" on a lab form is a hormone. In fact, ATTA are antibodies, not a hormone, and this confusion occurs more often than one would like.

ATTA: Decoding and What This Marker Is

ATTA (or ATG) are antibodies to thyroglobulin. Thyroglobulin is a protein produced by the follicular cells of the thyroid gland; it accumulates in the follicle as colloid and participates in the synthesis of thyroxine (T4) and triiodothyronine (T3). Antibodies to it are immune system proteins directed against the body's own thyroglobulin. This test belongs to the group of thyroid antibody studies.

ATTA and ATG — Hormone or Antibodies

The query "ATTA hormone" or "ATG hormone" is a common mistake. Thyroglobulin is not to be confused with thyroxine-binding globulin, which transports thyroid hormones in the blood. Thyroglobulin itself is not a hormone but a precursor protein. ATTA are even less a hormone and are a marker of immune reaction. Therefore, looking for a "normal ATTA hormone level" is pointless: these are antibodies.

Why Antibodies to Thyroglobulin Are Measured

This marker is used for diagnostic purposes. An elevated level of antibodies to thyroglobulin is often seen in patients with Hashimoto's thyroiditis or Graves' disease. Separately, thyroglobulin is used as a prognostic postoperative marker of differentiated (papillary or follicular) thyroid cancer; its level may be elevated in Graves' disease. To diagnose thyroid diseases, the doctor uses the medical history, examination, and thyroid tests, and in some cases a biopsy.

Why Antibodies to Thyroglobulin Are Elevated

An increase in ATTA is associated with autoimmune processes in the thyroid gland. In Hashimoto's thyroiditis, the immune system attacks the gland, and it cannot produce enough hormone. Hypothyroidism itself may manifest as fatigue, cold intolerance, weight gain, constipation, low mood, dry skin and hair, hoarseness, and irregular or heavy menstruation. Symptoms develop slowly. Hashimoto's thyroiditis is more common in women and usually begins at the age of 30–50, although hypothyroidism can develop in anyone.

• Hashimoto's thyroiditis
• Graves' disease
• the result is assessed by the doctor together with TSH and T4

How to Interpret the Result Together with TSH and Other Tests

ATTA are not assessed on their own. The doctor looks at TSH and T4 and, if necessary, orders other thyroid studies, including imaging and biopsy. Symptoms, family history, recent pregnancy, and examination of the neck for gland enlargement are taken into account. Elevated antibodies alone do not establish a diagnosis.

When a Doctor's Consultation Is Needed

You should see a doctor if symptoms of hypothyroidism appear or if the ATTA value on the lab form has increased. The doctor then decides which examinations are needed. If you are pregnant or planning a pregnancy, tell your doctor: additional tests are needed.

An elevated ATTA alone is not a reason to call an ambulance; 103/112 — if, against the background of severe hypothyroidism, the condition sharply worsens (myxedema coma is possible — an emergency condition requiring inpatient treatment).

This material is for reference: it helps to understand the lab form but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer