Biotin interference in immunoassay: a review for the laboratory scientist

The recent FDA Biotin (Vitamin B7): Safety Communication – May Interfere with Lab Tests and A statement from the ACB Scientific Committee regarding biotin/vitamin B7 interference in immunoassays have raised into the laboratory consciousness the need to understand and to manage the issues around biotin interference with some immunoassays and to provide education and advice to health-care providers. In patients who are prescribed biotin or take biotin supplements, biotin has the potential to cause falsely low or falsely high results in immunoassays using streptavidin–biotin binding as part of the assay methodology. Streptavidin–biotin binding is used by many manufacturers; some manufacturers use it for most of their immunoassays, some for a few of their immunoassays and some manufacturers do not use this assay format at all. The direction and magnitude of interference and the concentration of biotin which affects an assay are highly variable and assay specific. There have been many papers and case reports published recently of biotin interference in immunoassay, and biotin interference is probably one of the most difficult types of inference to detect and to obviate. This review will assess the currently available information on this topic and review the steps the laboratory can take to reduce the risk of incorrect patient results being reported.