Diagnostics Reference ranges for<unk>  may vary slightly, depending on the method of analysis, and do not necessarily equate to cut-offs for diagnosing thyroid dysfunction. In the UK, guidelines issued by the Association for Clinical Biochemistry suggest a reference range of 0.4–4.0 µIU/mL (or mIU/L). The National Academy of Clinical Biochemistry (NACB) stated that it expected the reference range for adults to be reduced to 0.4–2.5 µIU/mL, because research had shown that adults with an initially measured<unk>  level of over 2.0 µIU/mL had "an increased odds ratio of developing hypothyroidism over the following 20 years, especially if thyroid antibodies were elevated".<unk>  concentrations in children are normally higher than in adults. In 2002, the NACB recommended age-related reference limits starting from about 1.3 to 19 µIU/mL for normal-term infants at birth, dropping to 0.6–10 µIU/mL at 10 weeks old, 0.4–7.0 µIU/mL at 14 months and gradually dropping during childhood and puberty to adult levels, 0.3–3.0 µIU/mL. Diagnosis of disease<unk>  concentrations are measured as part of a thyroid function test in patients suspected of having an excess (hyperthyroidism) or deficiency (hypothyroidism) of thyroid hormones. Interpretation of the results depends on both the<unk>  and T4 concentrations. In some situations measurement of T3 may also be useful. Source of pathology<unk>  level Thyroid hormone level Disease causing conditions Hypothalamus/pituitary High High Benign tumor of the pituitary (adenoma) or thyroid hormone resistance Hypothalamus/pituitary Low Low Secondary hypothyroidism or "central" hypothyroidism Hyperthyroidism Low High Primary hyperthyroidism i.e. Graves' disease Hypothyroidism High Low Congenital hypothyroidism, Primary hypothyroidism i.e. Hashimoto's thyroiditis A<unk>  assay is now also the recommended screening tool for thyroid disease. Recent advances in increasing the sensitivity of the<unk>  assay make it a better screening tool than free T4. Monitoring The therapeutic target range<unk>  level for patients on treatment ranges between 0.3 and 3.0 μIU/mL. For hypothyroid patients on thyroxine, measurement of<unk>  alone is generally considered sufficient. An increase in<unk>  above the normal range indicates under-replacement or poor compliance with therapy. A significant reduction in<unk>  suggests over-treatment. In both cases, a change in dose may be required. A low or low-normal<unk>  value may also signal pituitary disease in the absence of replacement. For hyperthyroid patients, both<unk>  and T4 are usually monitored. In pregnancy,<unk>  measurements do not seem to be a good marker for the well-known association of maternal thyroid hormone availability with offspring neurocognitive development.<unk>  distribution progressively shifts toward higher concentrations with age. Difficulties with interpretation of<unk>  measurement * Heterophile antibodies (which include human anti-mouse antibodies (HAMA) and Rheumatoid Factor (RF)), which bind weakly to the test assay's animal antibodies, causing a higher (or less commonly lower)<unk>  result than the actual true<unk>  level. Although the standard lab assay panels are designed to remove moderate levels of heterophilic antibodies, these fail to remove higher antibody levels. "Dr. Baumann from Mayo Clinic and her colleagues found that 4.4 percent of the hundreds of samples she tested were affected by heterophile antibodies.........The hallmark of this condition is a discrepancy between<unk>  value and free T4 value, and most important between laboratory values and patient's conditions. Endocrinologists, in particular, should be on alert for this." * Macro-TSH - endogenous antibodies bind to<unk>  reducing its activity, so the pituitary gland would need to produce more<unk>  to obtain the same overall level of<unk>  activity. *<unk>  Isomers - natural variations of the<unk>  molecule, which have lower activity, so the pituitary gland would need to produce more<unk>  to obtain the same overall level of<unk>  activity. * The same<unk>  concentration may have a different meaning whether it is used for diagnosis of thyroid dysfunction or for monitoring of substitution therapy with levothyroxine. Reasons for this lack of generalisation are Simpson's paradox and the fact that the<unk> -T3 shunt is disrupted in treated hypothyroidism, so that the shape of the relation between free T4 and<unk>  concentration is distorted. Therapeutic A synthetic drug called recombinant human<unk>  alpha (rhTSHα or simply rhTSH) or thyrotropin alfa (INN) is manufactured by Genzyme Corp under the trade name Thyrogen. It is used to manipulate endocrine function of thyroid-derived cells, as part of the diagnosis and treatment of thyroid cancer.
Thyroid-stimulating hormone
Follicle-stimulating hormone
Parathyroid hormone-related protein
Parathyroid hormone
Thyroid hormone binding ratio
Thyroid hormones
Thyroid peroxidase
Calcitonin