Anti-thyroglobulin antibodies

Antibodies against thyroglobulin, the protein the thyroid stores its hormone in.

They point at the same autoimmune process as anti-TPO and are usually measured with it, since either alone can be negative.

Like anti-TPO this reads as positive or negative rather than as a trend; the titre is not a severity score. Their other use is technical -- they interfere with thyroglobulin measurement, so a laboratory checks them before reporting one.

Worth discussing together with anti-TPO and TSH.