"Biotin can significantly interfere in Allergy Testing" - FDA Safety Communication
Biotin, also known as vitamin B7, is an essential nutrient that is present in foods as well as in dietary supplements. In recent years, this molecule has gained commercial popularity for its claimed benefits for healthy hair and nail growth (Patel, D. 2017). Due to this perceived value, retail sales of biotin supplements in the US grew by more than 260 % from 2013 to 2016 (Wonderling, R. 2018). Further, Internet searches for the term "biotin" has gone up around 30 % from 2015 to 2020 due to the worldwide interest in the topic (Google Trends, 2020). Beyond the aesthetic use of the nutrient, doctors are also prescribing biotin for several health conditions including multiple sclerosis, diabetes, and dermatitis (Wonderling, R. 2018). There are no apparent adverse consequences to high doses of biotin; this has led many consumers to ingest biotin supplements with up to 650 times the recommended Adequate Intake (AI) of 30 mcg for a typical adult (National Institutes of Health, 2020).
In the past two years, there have been a number of reports demonstrating that biotin can interfere with certain lab tests and thereby generate incorrect results (Wonderling, R. 2018). For this reason, several international Competent Authorities are making known the increasing prevalence of inaccurate lab tests caused by biotin interference. For example, the FDA has issued a guideline indicating that "Incorrect test results may lead to inappropriate patient management or misdiagnosis" (FDA. 2017). More specifically, diagnostic assays which utilize the biotin-streptavidin interaction may be susceptible to elevated levels of biotin in patient serum, thereby generating false-negative results.
Biotin in Diagnostic Devices
Biotin interacts with streptavidin through one of the strongest non-covalent bonds found in nature; the interaction is biologically/chemically inert since it is highly specific, stable and resistant to changes in temperature and/or pH (Sinson, E. et al. 2019).
Mechanism of Biotin Interference in Specific IgE Assays
In many immunoassays, proteins or analytes of interest are biotinylated then added to a streptavidin-coated solid phase. Biotin interference is observed when endogenous biotin in the patient sample competes with the biotinylated protein of interest for binding sites on the streptavidin surface. This occurs in a homogeneous assay where patient sample and biotinylated analyte are co-incubated with the streptavidin-coated solid phase (See Figure. 1).
In heterogeneous assays like the NOVEOS assay (Figure 2), the biotinylated-protein is initially bound to the streptavidin-coated solid phase and this is then followed by a subsequent incubation with the patient sample. Any free biotin that is present in the patient sample cannot, therefore, inhibit the biotinylated reagent from binding to the solid phase.
In contrast to published reports that show inhibition in other streptavidin-biotin assays due to the increased use of biotin supplements in recent years, recent data confirms that the NOVEOS Specific IgE assay does not experience biotin interference (Sinson, E. et al 2019).
Google Trends (2020). Available at: https://trends.google.com/trends/explore?date=today%205-y&q=biotin [Accessed: 03-Jun-2020]
National Institute of Health (2020). Office of Dietary Supplements. Biotin, Fact Sheet for Health Professionals. Available at: https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/ [Accessed: 05-Jun-2020]
Patel DP, Swink SM, Castelo-Soccio L. (2017) A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017;3(3):166‐169. doi:10.1159/000462981. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5582478/ [Accessed: 03-Jun-20]
Sinson, E., Nguyen, S., Ocampo, C., Dinh, L., Liao, C. (2019) Evaluation of Biotin Interference in Specific IgE Assays Processed on the NOVEOS™ Immunoanalyzer*, Phadia™ 1000 System, and IMMULITE® 2000 Instrument. HYCOR Biomedical, Garden Grove, California, USA
Wonderling, R. (2018). A closer look at the recent FDA safety communication about biotin interference. Medical Laboratory Observer. Available at: https://www.mlo-online.com/diagnostics/assays/article/13009443/a-closer-look-at-the-recent-fda-safety-communication-about-biotin-interference [Accessed: 05-Jun-2020]