Keywords
Streptavidin
Thyroid hormones
Immunoassay
Thyroid function tests
False positive reactions
How to Cite
Abstract
Background: The use of vitamin supplements that include biotin during pregnancy can interfere with immunoassays based on the streptavidin/biotin system, causing falsely elevated or decreased results for various hormones, depending on the assay format.
Purpose: To present a clinical case in which biotin supplementation during pregnancy caused significant interference in TSH measurement, generating falsely elevated values.
Case presentation: A 29-year-old woman with a history of total thyroidectomy for papillary thyroid cancer had adequate suppression goals until she became pregnant. Despite multiple increases in levothyroxine dose, she did not achieve them. Given a levothyroxine dose greater than 2,50 µg/kg/day and the onset of clinical symptoms consistent with thyrotoxicosis, the possibility of analytical interference secondary to the use of prenatal multivitamins containing biotin in the immunoassay used for TSH quantification was raised. These supplements were discontinued 72 hours before the next follow-up, which demonstrated a significant decrease in levels.
Discussion and conclusion: Biotin interference in noncompetitive immunoassays often results in falsely low TSH levels; however, at very high concentrations—such as those resulting from megadoses of prenatal supplements—it can produce the opposite effect. Streptavidin saturation and the formation of unstable complexes alter the kinetics of the assay, generating an increased light signal and falsely elevated TSH values.
Biotin consumption can interfere with TSH measurement in immunoassays, generating falsely high or low results, leading to the administration of inappropriate and potentially harmful treatments for patients.
References
Luong JHT, Male KB, Glennon JD. Biotin interference in immunoassays based on biotin-strept(avidin) chemistry: an emerging threat. Biotechnol Adv. 2019;37(5):634-41. https://doi.org/10.1016/j.biotechadv.2019.03.007
Pacheco-Alvarez D, Solórzano-Vargas RS, León Del Río A. Biotin in metabolism and its relationship to human disease. Arch Med Res. 2002;33(5):439-47. https://doi.org/10.1016/s0188-4409(02)00399-5
Trambas CM, Sikaris KA, Lu ZX. More on biotin treatment mimicking Graves' disease. N Engl J Med. 2016;375(17):1698. https://doi.org/10.1056/nejmc1611875
Holmes EW, Samarasinghe S, Emanuele MA, Meah F. Biotin interference in clinical immunoassays: a cause for concern. Arch Pathol Lab Med. 2017;141(11):1459-60. https://doi.org/10.5858/arpa.2017-0107-le
Paczkowska K, Otlewska A, Loska O, Kola?kov K, Bolanowski M, Daroszewski J. Laboratory interference in the thyroid function test. Endokrynol Pol. 2020;71(6):551-60. https://doi.org/10.5603/ep.a2020.0079
Esteban Jiménez Ó, Letosa Gaudó J, Moreno Juste A, Urieta González L, González Rubio F. Interferencia de la biotina en las pruebas de función tiroidea. Semergen. 2021;47(1):e1-2. https://doi.org/10.1016/j.semerg.2020.06.018
Ylli D, Soldin SJ, Stolze B, Wei B, Nigussie G, Nguyen H, et al. Biotin interference in assays for thyroid hormones, thyrotropin and thyroglobulin. Thyroid. 2021;31(8):1160-70. https://doi.org/10.1089/thy.2020.0866
Dasgupta A. Immunoassay design and biotin interference. Adv Clin Chem. 2022;109:165-83. https://doi.org/10.1016/bs.acc.2022.03.005
James A, Stalan J, Kuzhively J. Biotin-induced biochemical hyperthyroidism: a case report and review of the literature. J Med Case Rep. 2023;17(1):266. https://doi.org/10.1186/s13256-023-04002-z
Bouillet B, Rouland A. La prise de biotine à fortes doses: une cause d’hyperthyroïdie biologique factice. Rev Med Interne. 2020;41(2):123-5. https://doi.org/10.1016/j.revmed.2019.11.005
Mrosewski I, Neumann I, Switkowski R. Interference of high-dose biotin supplementation with thyroid parameters in immunoassays utilizing the interaction between streptavidin and biotin: a case report and review of current literature. Clin Lab. 2019;65(1). https://doi.org/10.7754/clin.lab.2018.180637
Lam L, Bagg W, Smith G, Chiu WW, Middleditch MJ, Lim JC, et al. Apparent hyperthyroidism caused by biotin-like interference from IgM anti-streptavidin antibodies. Thyroid. 2018;28(8):1063-7. https://doi.org/10.1089/thy.2017.0673
Rosner I, Rogers E, Maddrey A, Goldberg DM. Clinically significant lab errors due to vitamin B7 (biotin) supplementation: a case report following a recent FDA warning. Cureus. 2019;11(8):e5470. https://doi.org/10.7759/cureus.5470
Kummer S, Hermsen D, Distelmaier F. Biotin treatment mimicking Graves' disease. N Engl J Med. 2016;375(7):704-6. https://doi.org/10.1056/nejmc1602096
Hattori N, Ishihara T, Shimatsu A. Variability in the detection of macro TSH in different immunoassay systems. Eur J Endocrinol. 2016;174(1):9-15. https://doi.org/10.1530/eje-15-0883
Balieiro Neto G, Engracia Filho JR, Lemos Budino FE, de Paula Freitas AW, Boas Soares WV. Effects of high-biotin sample interference on antibody concentrations in sandwich immunoassays. Vaccines. 2023;11(11):1627. https://doi.org/10.3390/vaccines11111627
Jiajia N, Long Y, Jingyi L, Zhang L, Yang Q, Kou C, et al. Interference due to heterophilic antibody, biotin and thyroid hormone autoantibody. Research Square. 2021. https://doi.org/10.21203/rs.3.rs-352785/v1
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Copyright (c) 2026 Revista Colombiana de Endocrinología, Diabetes & Metabolismo