Biotin and high-sensitivity cardiac troponin T assay

Abstract

IntroductionThe high-sensitivity cardiac troponin T assay of Roche Diagnostics is known to have interference with high concentrations of biotin as this assay uses biotin-streptavidin binding as detection method. As studies so far have not shown if different biotin concentrations could have diverse influence on various troponin concentrations and whether interference could be removed by available protocol within corresponding turnaround time we aimed to investigate it.Materials and methodsPlasma samples were spiked with different concentration of biotin solution. Troponin T concentrations were tested on a Roche Cobas® 8000 module 602 analyser. Final concentrations of biotin and troponin T were 50, 100, 500 and 1000 μg/L and 18, 59, 201 and 6423 ng/L, respectively. Impact of different incubation times following biotin neutralization protocol described by Piketty et al. was also tested.ResultsWe observed a mean of negative biases of 24, 56, 97, and 98% of the troponin T expected value at biotin concentrations of 50, 100, 500, 1000 μg/L. Neutralization protocol was applied on the sample with initial concentration of TnT of 59 ng/L at a biotin concentration of 1000 μg/L. Same results across different incubation times from 60 to 0 minutes were obtained (mean value 56.8 ng/L, coefficient of variation of 1.31%). We demonstrated that neutralization process had a dilution effect of the troponin concentration (loss of 4.5% to 9.6% of initial troponin value).ConclusionsBiotin interference is not dependent of initial troponin value. Interference could be successfully neutralized within a time frame compatible with emergency but results still should be carefully interpreted due to possible dilution effect.

Interference From High-Dose Biotin Intake in Immunoassays for Potentially Time-Critical Analytes by Roche

“…However, these analytes comprise only a fraction of the ones in this study, and shorter incubation times should be evaluated for all concerned assays before they are applied to minimize the increase in turnaround times even further. Schrapp et al 33 described that the interference in troponin T hs is independent of initial troponin concentrations, an observation that we also made in most tested competitive and sandwich immunoassays, with the exception of NT-proBNP. Trambas et al, 2 on the other hand, found the interference of biotin caused proportional changes in sandwich immunoassays regardless of initial analyte concentrations, whereas competitive immunoassays showed a particularly exaggerated positive bias in samples with low analyte concentrations.…”

“…The adsorption caused an increase in the CVs and analytical imprecision in all tested assays, with the exception of cortisol, FT3, NT-proBNP, and procalcitonin, when compared with the manufacturer-supplied CVs in a comparable parameter range (Tables 2 and 3). Schrapp et al 33 made the same observation in their evaluation of biotin depletion in the Elecsys assay for troponin T hs. The increased CVs should not be problematic in most analytes, with the exception of troponin T hs and HIV.…”

“…The H0/H3 protocol is a suitable alternative. 33,37 In suspected HIV, low-level positive or high-level negative results for samples treated with the depletion protocol should be repeated on an alternate platform because of the decreased precision.…”

“…distort free to total hormone equilibrium, and thus measured values. 33 A further important source of possible error is inadequate immobilization of the streptavidin microparticles and contamination of the aspirated sample with streptavidin microparticles during pipetting. 33 The biotin depletion procedure requires manual handling, care, and attentiveness, and can therefore be prone to human error.…”

“…33 A further important source of possible error is inadequate immobilization of the streptavidin microparticles and contamination of the aspirated sample with streptavidin microparticles during pipetting. 33 The biotin depletion procedure requires manual handling, care, and attentiveness, and can therefore be prone to human error. 33 The experimental setup in this study resulted in prolonged air exposure in tacrolimus and cyclosporine A assays, which is cautioned against in Roche's method sheets and might have resulted in a reduced recovery in these analytes.…”