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A patient comes to you with a thyroid function test suggestive of Thyrotoxicosis, but the patient has absolutely no clinical features of the same. What do you do ?
A patient comes to you with a thyroid function test suggestive of Thyrotoxicosis, but the patient has absolutely no clinical features of the same. What do you do ?
In such a scenario, you need to look for Biotin interference with endocrine lab assay
50% of endocrine tests have been developed using biotin in their separation step
50% of endocrine tests have been developed using biotin in their separation step
A high dose of biotin (defined as biotin intake >5 mg /day) is often a component of dermatological treatment. It is also a treatment for multiple sclerosis.
Typically Biotin produces false low for large molecules like TSH, FSH, LH, HCG etc
And false high for small molecules- T3/T4, Cortisol etc
(If tested using Immunoassays)
And false high for small molecules- T3/T4, Cortisol etc
(If tested using Immunoassays)
Hence typically a patient can have a picture of thyrotoxicosis with high dose biotin use - false high T3 and T4 and false low TSH
Interestingly, even "TSH receptor antibody" can be false high leading to a misdiagnosis of Graves' disease!
In such a case, it would be a good idea to stop Biotin for 2-5 days and then repeat the test
