Effects of Biotin Supplements Ingestion on Beckman Biotinylated Immunoassays

Abstract

Abstract Background Biotin is a water-soluble B vitamin with high affinity for streptavidin binding. The biotin-streptavidin amplification strategy is widely used to increase the analytical sensitivity of clinical laboratory tests, which are also vulnerable to biotin interference. The aim of this study is to evaluate the effects of the orally taken biotin supplements on Beckman biotinylated immunoassays. Methods Twelve volunteers were recruited to ingest a single dose of 10 mg biotin after fasting of multivitamin supplements for 3 days. Blood samples were collected at 0, 0.5, 1, 2, and 4 hours postingestion. Eleven biotinylated and nonbiotinylated immunoassays were performed on Beckman DXI and on Abbott Architect as a comparison. Results Ingestion of a single dose of 10 mg biotin caused falsely high values in biotinylated competitive immunoassays such as free triiodothyronine (fT3), total T3 (TT3), and free thyroxine (fT4) assays and falsely low values in biotinylated sandwich immunoassays such as thyroglobulin (Tg) and GI 19-9. The interference started at 0.5 hour postingestion, peaked at 1 hour postingestion, and continued at 4 hours postingestion. The extent of interference is different among these analytes. TT3 showed a maximum of a 219% increase of concentration, while GI 19-9 showed a maximum of a 25% decrease of concentration. fT3, fT4, and Tg showed intermediate changes of concentrations. The interference was not seen in nonbiotinylated immunoassays performed on Beckman DXI or Abbott Architect. Conclusions Single dose of biotin ingestion at the dosage of over-the-counter supplements can induce significant interference in certain biotinylated immunoassays and lead to incorrect test results.