Elston Marianne S, Sehgal Shekhar, Du Toit Stephen, Yarndley Tania, Conaglen John V
Departments of Endocrinology (M.S.E., S.S., T.Y.) and Chemical Pathology (S.D.T.), Waikato Hospital, Hamilton 3240, New Zealand; and Waikato Clinical Campus, University of Auckland (M.S.E., J.V.C.), Hamilton 3240, New Zealand.
J Clin Endocrinol Metab. 2016 Sep;101(9):3251-5. doi: 10.1210/jc.2016-1971. Epub 2016 Jun 30.
Biotin (vitamin B7) is an essential co-factor for four carboxylases involved in fatty acid metabolism, leucine degradation, and gluconeogenesis. The recommended daily intake (RDI) of biotin is approximately 30 μg per day. Low-moderate dose biotin is a common component of multivitamin preparations, and high-dose biotin (10 000 times RDI) has been reported to improve clinical outcomes and quality of life in patients with progressive multiple sclerosis. Biotin is also a component of immunoassays, and supplementation may cause interference in both thyroid and non-thyroid immunoassays.
To assess whether biotin ingestion caused abnormal thyroid function tests (TFTs) in a patient through assay interference.
We report a patient with biotin-associated abnormal TFTs and a systematic review of the literature.
A tertiary endocrine service in Hamilton, New Zealand.
The patient had markedly abnormal TFTs that did not match the clinical context. After biotin cessation, TFTs normalized far more rapidly than possible given the half-life of T4, consistent with assay interference by biotin. Multiple other analytes also tested abnormal in the presence of biotin.
Biotin ingested in moderate to high doses can cause immunoassay interference. Depending on the assay format, biotin interference can result in either falsely high or low values. Interference is not limited to thyroid tests and has the potential to affect a wide range of analytes. It is important for clinicians to be aware of this interaction to prevent misdiagnosis and inappropriate treatment.
生物素（维生素B7）是参与脂肪酸代谢、亮氨酸降解和糖异生的四种羧化酶的必需辅助因子。生物素的推荐每日摄入量（RDI）约为每日30微克。低 - 中等剂量的生物素是多种维生素制剂的常见成分，据报道，高剂量生物素（RDI的10000倍）可改善进行性多发性硬化症患者的临床结局和生活质量。生物素也是免疫测定的一种成分，补充生物素可能会干扰甲状腺和非甲状腺免疫测定。
评估生物素摄入是否通过测定干扰导致患者甲状腺功能测试（TFT）异常。
我们报告了一名患有生物素相关TFT异常的患者，并对文献进行了系统综述。
新西兰汉密尔顿的一家三级内分泌服务机构。
该患者的TFT明显异常，与临床情况不符。停止摄入生物素后，TFT恢复正常的速度比根据T4半衰期预期的要快得多，这与生物素的测定干扰一致。在存在生物素的情况下，多种其他分析物的检测结果也异常。
中等至高剂量摄入生物素可导致免疫测定干扰。根据测定形式，生物素干扰可导致值假性升高或降低。干扰不仅限于甲状腺测试，还可能影响广泛的分析物。临床医生了解这种相互作用对于防止误诊和不适当治疗很重要。
