🦋 Autoimmune Thyroid — Hashimoto's & Graves'

What this panel can settle, and by what logic

The reason to run the antibodies together rather than one at a time is that they point at two diseases with opposite treatments, and the hormones alone cannot always tell you which one you are looking at.

1. Thyroid Antibodies (TPO + TgAb) and Thyroglobulin Antibody establish Hashimoto's. Thyroid peroxidase antibody is the workhorse; thyroglobulin antibody catches part of the remainder. Hashimoto's is the commonest autoimmune thyroid disease and it runs 7 to 10 times more often in women than in men Klubo-Gwiezdzinska 2022.
2. Thyroid-Stimulating Immunoglobulin (TSI) establishes the opposite disease. A suppressed TSH (Thyroid-Stimulating Hormone) with a raised Free T4 (Thyroxine) can be Graves' disease, which is treated by suppressing the gland, or the destructive phase of a thyroiditis, which is treated by waiting. A stimulating immunoglobulin argues for the first, and it is also the antibody that matters in pregnancy because it crosses the placenta.
3. Free T3 (Triiodothyronine) with Free T4 (Thyroxine) and TSH says which of the three states you are in. Autoimmune thyroid disease presents as thyrotoxicosis while stored hormone leaks from destroyed follicles, as euthyroidism while surviving tissue compensates, or as hypothyroidism once it cannot — and the management differs at each Klubo-Gwiezdzinska 2022.
4. Ferritin and Selenium, Blood are the two inputs worth excluding. Both are commonly low, both are cheap, and neither is a treatment for the autoimmunity itself.

What it cannot settle, and what would

Antibodies cannot tell you when, or whether, you will become hypothyroid. They tell you the process is running. What converts that into a timeline is repeated TSH measurement over years, which is what the longitudinal follow-up of a general population cohort was for Razvi 2024, and it is why the recommendation for an antibody-positive euthyroid person is periodic TSH rather than treatment Klubo-Gwiezdzinska 2022. There is nothing in a titre that shortens that wait.

It cannot separate Graves' from a destructive thyroiditis on its own when the antibody is negative. A negative Thyroid-Stimulating Immunoglobulin (TSI) narrows the odds; it does not close the question, and the tests that do are a radioiodine uptake scan or ultrasound with Doppler. Getting this wrong costs months on the wrong drug, because one of these two conditions resolves by itself.

Thyroxine Binding Globulin (TBG) at $50 is close to redundant on this particular list. Thyroxine-binding globulin explains discordant TOTAL T4 and T3 results, and this panel measures the FREE fractions, which are buffered against binding-protein changes by design Al-Bahadili 2024. It earns its place only if a total-hormone result from elsewhere is what needs explaining. Thyroglobulin Antibody has a second and larger job in thyroid cancer follow-up, where its presence changes how thyroglobulin itself can be measured at all, and an expert consensus exists to say how Giovanella 2023.

And it cannot exclude the rare structural outcomes. Hashimoto's carries about a 1.6-fold higher risk of papillary thyroid cancer and a 60-fold higher risk of thyroid lymphoma than the general population Klubo-Gwiezdzinska 2022 — a large multiple of two uncommon events, and no antibody tracks either. A new or growing lump is an ultrasound, whatever the titres say.

Draw conditions that decide whether the money is wasted

Here the antibodies are the easy part and the hormones are the fragile part, which reverses the usual advice.

1. Biotin off for 72 hours, and on this panel it can invent a diagnosis. High-dose biotin pushes TSH down and free T4 up on streptavidin-based analyzers, which is the biochemical picture of Graves' disease; on a panel that also carries a stimulating immunoglobulin, that pattern gets acted on Li 2020 Al-Bahadili 2024. Six of these nine markers run on the same chemistry.
2. Antibody titres need no timing at all. No cycle day, no fasting, no morning requirement, and no reason to repeat one that is already positive. It is the TSH (Thyroid-Stimulating Hormone), Free T4 (Thyroxine) and Free T3 (Triiodothyronine) that need a morning tube taken before any levothyroxine dose.
3. Say whether you are pregnant, postpartum, or taking estrogen. Estrogen raises thyroxine-binding globulin, which is the one thing on this panel Thyroxine Binding Globulin (TBG) can actually explain, and pregnancy shifts the TSH interval itself Al-Bahadili 2024.
4. Ask which platform ran it, and stay on it. The American Thyroid Association's own review concludes that thyroid assays are still not standardized well enough for results from different methods to be treated as equivalent Van Uytfanghe 2023, so a TSH that moved between two laboratories may not have moved at all.

How you would know it answered your question, and what each pattern means next

Five patterns, and one of them has a number attached that changes how long you wait.

• Positive Thyroid Antibodies (TPO + TgAb) with a normal TSH (Thyroid-Stimulating Hormone): monitor, do not medicate. Annual TSH is the usual interval and the antibody does not need repeating Klubo-Gwiezdzinska 2022.
• Raised TSH (Thyroid-Stimulating Hormone) with positive antibodies: this is the combination least likely to sort itself out. In the pooled trial data on spontaneous normalization of a raised TSH, the ABSENCE of thyroid peroxidase antibodies was one of the independent predictors of normalizing van der Spoel 2023 — so an antibody-positive elevation is the one worth repeating at 8 to 12 weeks and then acting on.
• Suppressed TSH with a raised Free T4 (Thyroxine) and a positive Thyroid-Stimulating Immunoglobulin (TSI): endocrinology, promptly, and sooner still if you are pregnant or planning to be. This is the one result on the panel with a clock on it.
• On levothyroxine already: the replacement dose scales with preserved thyroid function and lean body mass and usually runs 1.4 to 1.8 mcg/kg/day Klubo-Gwiezdzinska 2022, and any change is re-checked at 6 to 8 weeks because that is how long the pituitary takes to re-equilibrate.
• Low Selenium, Blood: correct a deficiency if it exists, but do not expect it to treat the antibodies. One overview reports a signal and one systematic review finds the evidence insufficient to support the practice Wang 2023 Qiu 2021, which is not a basis for a long-term supplement.

Sources read for these sections

• Klubo-Gwiezdzinska J, Wartofsky L. Hashimoto thyroiditis: an evidence-based guide to etiology, diagnosis and treatment. Polish Archives of Internal Medicine 2022 · PMID 35243857
• van der Spoel E, et al. Incidence and Determinants of Spontaneous Normalization of Subclinical Hypothyroidism in Older Adults. Journal of Clinical Endocrinology and Metabolism 2023 · PMID 37862463
• Razvi SS, et al. Changes in Thyroid Function and Autoimmunity in Older Individuals: Longitudinal Analysis of the Whickham Cohort. Journal of Clinical Endocrinology and Metabolism 2024 · PMID 39673773
• Giovanella L, et al. Thyroglobulin and thyroglobulin antibody: an updated clinical and laboratory expert consensus. European Journal of Endocrinology 2023 · PMID 37625447
• Van Uytfanghe K, et al. Thyroid Stimulating Hormone and Thyroid Hormones (Triiodothyronine and Thyroxine): An American Thyroid Association-Commissioned Review of Current Clinical and Laboratory Status. Thyroid 2023 · PMID 37655789
• Al-Bahadili H, et al. The Complex Web of Interferences with Thyroid Function Tests. Endocrine Practice 2024 · PMID 39477092
• Wang YS, et al. The Effects of Selenium Supplementation in the Treatment of Autoimmune Thyroiditis: An Overview of Systematic Reviews. Nutrients 2023 · PMID 37513612
• Qiu Y, et al. Insufficient evidence to support the clinical efficacy of selenium supplementation for patients with chronic autoimmune thyroiditis. Endocrine 2021 · PMID 33774780
• Li D, Ferguson A, Cervinski MA, Lynch KL, Kyle PB. AACC Guidance Document on Biotin Interference in Laboratory Tests. J Appl Lab Med 2020 · PMID 32445355