FDA Resounds the Alarm on Biotin Test Interference

In early November 2019, the FDA undated a previous safety communication about the potential of biotin to significantly interfere with diagnostic tests. The update reiterates the warning to lab personnel, diagnostic test developers, providers and patients that biotin can lead to incorrect lab test results. Biotin Blinding Biotin, or Vitamin B7, is a water-soluble vitamin commonly used as an ingredient in multi-vitamins, prenatal vitamins and dietary supplements marketed for hair, skin and nail growth. Because biotin bonds with specific proteins that can be measured to detect certain health conditions, many lab tests rely on biotin-detection based methods and technology. The problem is that biotin can distort lab test results leading false highs and false lows, especially when tested patients consume high levels of biotin. And such high consumption is far from abnormal given how much of it producers use. Thus, for example, dietary supplements may contain up to 650 times more biotin than recommended daily values. FDA Reaction to Biotin Interference In 2017, the FDA issued a safety communication addressing biotin interference with certain in vitro diagnostic tests and has since issued recommendations for lab personnel and test manufacturers to minimize the potential for interference. The FDA expressed specific concern about biotin interference resulting in falsely low levels of troponin—the biomarker that aids in diagnosis of heart attacks. Misleading diagnoses as a result of incorrect lab results could lead to potentially serious clinical implications, the FDA cautioned. Since the 2017 safety communication, some lab test developers have been successful at minimizing biotin interference of their assays, according to the updated safety communication, but others have not yet addressed it. The troponin problem remains of particular concern as the FDA continues to receive adverse events reports indicating that biotin interference caused falsely low troponin results. Recommendations for Providers The newly revised communication lays out recommendations for providers to minimize the risk of biotin interference, including:

• Discussing biotin and multivitamin supplements with patients;
• Notifying labs if patients being tested are taking biotin;
• Considering biotin interference as a source of error if lab test results don’t match clinical presentation; and
• Reporting to the laboratory manufacturer and FDA if they become aware of patients experiencing adverse events following potentially incorrect lab test results due to biotin interference.

 Recommendations for Labs The communication also recommends that labs and testing personnel:

• Be aware that it’s difficult to identify samples that contain biotin if assays are used with biotin technology, and to communicate with health care providers and patients to prevent incorrect test results;
• Ask patients if they’re taking biotin or a biotin-containing supplement when collecting samples;
• Educate health care providers about biotin interference with lab tests;
• Understand that biotin levels higher than the recommended daily allowance of .03 mg may cause significant interference with lab tests;
• Be aware that specimens collected from patients taking high levels of biotin may contain more than 100 ng/mL biotin;
• Recognize that currently available data is insufficient to support recommendations for safe testing using affected tests in patients taking high levels of biotin, including about the length of time for biotin clearance from the blood;
• Communicate with the lab test manufacturer if there are questions about biotin interference; and
• Be aware of certain troponin assays where the risk of biotin interference hasn’t yet been addressed.

Recommendations for Lab Manufacturers Last but not least, the communication calls on lab test manufacturers and developers to:

• Contact the FDA to discuss biotin interference if an assay uses biotin technology;
• Investigate interference from biotin (up to at least 1200 ng/mL biotin) in assays that use biotin technology and determine the lowest concentration of biotin that may cause clinically significant interference with test(s);
• Communicate to customers that may be unaware that a test uses biotin technology and how it may be affected; and
• Contact the FDA with any questions about biotin technology and interference.