Which lab test concern can arise from long-term high-dose biotin use?

• A. Elevated liver enzymes
• B. Interference with immunoassays leading to inaccurate results
• C. Kidney function changes
• D. Hematologic abnormalities

Answer: (B)

High-dose biotin can disrupt laboratory immunoassays that rely on biotin-streptavidin chemistry, leading to inaccurate results. When a patient has a lot of biotin in their blood from supplements, it can compete with or block the assay’s biotin-streptavidin interactions. In sandwich immunoassays, this interference can cause falsely low readings because the capture step is impaired. In competitive immunoassays, it can cause falsely high readings for the same reason. Because many common lab tests (such as thyroid function tests, vitamin levels, and some cardiac markers) use biotin-streptavidin formats, long-term high-dose biotin use can skew multiple results. Clinicians should ask about biotin intake and may instruct a temporary pause before testing to ensure accurate results.