Biotin Interference in Laboratory Tests

Mechanism of Interference

Biotin from over-the-counter dietary supplements interferes with biotin-streptavidin based immunoassays through competitive binding mechanisms, causing falsely elevated results in competitive assays and falsely decreased results in sandwich (noncompetitive) assays, with the direction and magnitude of interference varying by specific test and manufacturer 1
In competitive assays, excess biotin causes false-positive (falsely elevated) results by competing with biotinylated reagents 1
In sandwich assays, excess biotin causes false-negative (falsely decreased) results by blocking streptavidin binding sites 1

Troponin assays are particularly vulnerable to biotin interference, which can result in falsely low troponin levels and potentially missed myocardial infarctions 1
This represents a critical patient safety concern in emergency cardiac evaluations, as falsely low cardiac troponin in patients with acute coronary syndrome can lead to missed myocardial infarction diagnosis 1

The most dangerous scenario is falsely low cardiac troponin in patients with acute coronary syndrome, which can lead to missed myocardial infarction diagnosis and represents a life-threatening misdiagnosis 1

Biotin supplementation can alter measured parathyroid hormone (PTH) concentrations, and the direction and magnitude of this interference depend on the specific immunoassay platform employed (e.g., some platforms show falsely decreased values, others are less affected) 2