Best Practice Workflow for Mitigating Biotin Interference in Laboratory Immunoassays
High-dose biotin supplementation poses a growing interference risk for immunoassays, particularly thyroid hormones, cardiac markers, and immunosuppressive drug tests. The authors propose a structured workflow for laboratory scientists: serial dilution, retesting after biotin clearance or on an alternate platform, and confirmation via biotin depletion or direct measurement. Several case studies illustrate the potential for misdiagnosis of Graves' disease when biotin interference goes unrecognised.
The original study
Best practices in mitigating the risk of biotin interference with laboratory testing.
- Authors
- Bowen R, Benavides R, Colón-Franco JM, Katzman BM, Muthukumar A, Sadrzadeh H, et al.
- Journal
- Clinical biochemistry
- Type
- Journal Article, Review
- PMID
- 31473202
Original abstract
Dietary biotin intake does not typically result in blood biotin concentrations that exceed interference thresholds for in vitro diagnostic tests. However, recent trends of high-dose biotin supplements and clinical trials of very high biotin doses for patients with multiple sclerosis have increased concerns about biotin interference with immunoassays. Estimates of the prevalence of high biotin intake vary, and patients may be unaware that they are taking biotin. Since 2016, 92 cases of suspected biotin interference have been reported to the US Food and Drug Administration. Immunoassays at greatest risk from biotin interference include thyroid and reproductive hormones, cardiac, and immunosuppressive drug tests. Several case studies have highlighted the challenge of biotin interference with thyroid hormone assays and the potential misdiagnosis of Graves' disease. Biotin interference should be suspected when immunoassay test results are inconsistent with clinical information; a clinically relevant biotin interference happens when the blood biotin concentration is high and the assay is sensitive to biotin. We propose a best practice workflow for laboratory scientists to evaluate discrepant immunoassay results, comprising: (1) serial dilution; (2) retesting after biotin clearance and/or repeat testing on an alternate platform; and (3) confirmation of the presence of biotin using depletion protocols or direct measurement of biotin concentrations. Efforts to increase awareness and avoid patient misdiagnosis should focus on improving guidance from manufacturers and educating patients, healthcare professionals, and laboratory staff. Best practice guidance for laboratory staff and healthcare professionals would also provide much-needed information on the prevention, detection, and management of biotin interference.