Clinical Biochemistry | December 4, 2014

Wu AHB, van Wijk XMR
Clinical  Biochemistry 2014
DOI: 10.1016/j.clinbiochem.2014.11.018

Dear Editor: As reviewed recently [1], there is considerable clinical interest in the development and possible implementation of highly sensitive cardiac troponin I (cTnI) assays for early rule out of acute coronary syndromes[2], short-term (30 days) risk stratification for future adverse cardiac events [3], and for detecting cardiac injury among asymptomatic patients [4]. Current assays in contemporary practice are unable to detect cTnI in the blood of all healthy subjects. In a study of 19 commercial cTnI assays, Apple et al. [5] reported the limit of detection ranging from 0.09 to 160 ng/L. Only the Singulex Erenna assay was able to detect troponin in all of the 524 apparently healthy subjects [6]. Subsequent to that study, another manufacturer (Quanterix Corp., Lexington MA) developed a prototype research assay, run on the fully automated Simoa HD-1 Analyzer, with an LOD of 0.010 ng/L, upper dynamic range of 1200 ng/L, and total precision of 10.2%, 6.0%, and 6.2% at 2.0, 5.7, and 54.4 ng/L, and a 99th percentile of 8.4 ng/L. The assay uses 42 μL of sample and the time to first result is 45min.