Evaluating the performance of an updated high-sensitivity troponin T assay with increased tolerance to biotin

Abstract

Objectives: Biotin >20 ng/mL may interfere with the Elecsys® Troponin T-high sensitive assay (cTnT-hs; Roche Diagnostics International Ltd). We evaluated the performance of an updated assay, cTnT-hs∗, which was designed to reduce biotin interference. Methods: cTnT-hs∗ assay performance was assessed using up to two applications (18 min/9 min) on three analyzers (cobas e 411/cobas e 601/cobas e 801). Biotin interference was determined by measuring recovery in an 11-sample series dilution with biotin ranging from 0-3600 ng/mL. Repeatability/reproducibility were evaluated in five serum sample pools (n=75 each). Method comparisons tested: cTnT-hs∗ vs. cTnT-hs (18 min/cobas e 601); cTnT-hs∗ assay 18 vs. 9 min (cobas e 601); cTnT-hs∗ (18 min) on cobas e 601 vs. cobas e 411 and cobas e 601 vs. cobas e 801. Concordance at the 99th percentile decision limit between cTnT-hs∗ and cTnT-hs (9 min/cobas e 601) was calculated using 300 lithium-heparin plasma samples and a 14 ng/L assay cutoff. Results: cTnT-hs∗ assay (18 min/cobas e 601) recovery was ≥96% for biotin ≤1250 ng/mL. Across all applications/analyzers, coefficients of variation for repeatability/reproducibility with the cTnT-hs∗ assay were <5% in most serum sample pools (mean cardiac troponin T: 8.528-9484 ng/L). High correlation (Pearson's r=1.000) was demonstrated for all method comparisons. Concordance at the 99th percentile decision limit was high between the cTnT-hs∗ and cTnT-hs assays. Conclusions: The updated cTnT-hs∗ assay may provide greater tolerance to biotin interference, and shows good analytical and clinical agreement/concordance with the previous cTnT-hs assay.