Hidden Risks: Biotin's Impact on Cardiac Troponin Assays

Original Article: Susceptibility of Cardiac Troponin Assays to Biotin Interference

What are the key takeaways of this article?

Over-the-counter biotin supplements have increased in popularity due to their perceived cosmetic and health benefits. The over-the-counter doses are often 5-10 mg/d, which is 150 times more than the intake recommendations. Notably, these high doses can lead to interference with laboratory markers, particularly cardiac troponin (cTn) assays. Sandwich immunoassays for detecting proteins like cTn rely on two antibodies - one biotinylated capture antibody and one coupled to a reporter molecule. The cTn antibody complexes are then bound to streptavidin for detection. However, excess biotin in cTn assays can potentially interfere by binding to streptavidin, leading to the underestimation of myocardial injury, including myocardial infarction. This interaction has been previously identified in thyroid function tests. However, because thyroid function results are usually non emergent, physicians can utilize wash-out periods as a mitigator. Unfortunately, a wash-out is unrealistic in the time-sensitive scenarios that troponins are used for.

This study aimed to understand the potential consequences of biotin interference in cTn assays and its clinical impact. To accomplish this goal, the authors conducted four studies to evaluate the effects of biotin on cTn measurements. They compared the Gen 5 cTnT assay with a contemporary cTnT assay (Roche Diagnostics) and a research-based hs-cTnI assay (Abbott STAT). The research focused on the interference of biotin in cTn measurements and included experiments with healthy volunteers consuming biotin, simulations of biotin ingestion in troponin-positive patients, and evaluation of the effectiveness of streptavidin pretreatment in blocking biotin in patient samples.

Upon reviewing the results, the series of four studies demonstrated significant interference from biotin on troponin assays, particularly in the Gen 5 cTn T assay. Clinically, the study suggests potential delays in myocardial infarction diagnosis due to biotin interference, particularly with the Gen 5 cTnT assay, and recommends longer assessment times for cases with suspected biotin interference. Additionally, the study highlights the need for careful consideration of biotin's effects on immunoassays in clinical practice and calls for increased awareness among healthcare providers.

In summary, this study aimed to investigate the interference of biotin in detecting cardiac troponins among different immunoassays. This study is of relevance to dermatology as many patients consume biotin for perceived cosmetic and health benefits. The results align with the FDA's warning regarding the influence of biotin on certain cTn measurements, especially in the case of the Gen 5 cTnT assay. The Gen5 cTnT assay may experience interference from biotin at levels attainable through the consumption of over-the-counter supplements, potentially resulting in delayed or overlooked diagnosis of myocardial injury. Assessing the frequency of significant biotin consumption among the population will be crucial in comprehending the potential clinical consequences of biotin interference. Similarly, having open discussions with patients about over-the-counter supplements is important in combination with knowing what cTn assays are used in a particular region.

Publication Date: November 20th, 2023

Reference: Frame IJ, Joshi PH, Mwangi C, Gunsolus I, De Lemos JA, Das SR, Sarode R, Balani J, Apple FS, Muthukumar A. Susceptibility of cardiac troponin assays to biotin interference. American journal of clinical pathology. 2019 Mar 22;151(5):486-93.

Summary By: McKenzie Van Eaton