Analytical Performance of the New Sysmex High-Sensitivity Troponin T Assay

Area of Science:

• Clinical Chemistry
• Cardiovascular Diagnostics
• Immunoassay Technology

Background:

• High-sensitivity cardiac troponin T (hs-cTnT) assays are crucial for diagnosing acute myocardial infarction.
• Evaluating new diagnostic platforms like the Sysmex Highly Integrated Single-Cartridge Luminescence Immunoassay System (HISCL) is essential for clinical practice.
• Comparison with established assays and determination of reference limits are key performance indicators.

Purpose of the Study:

• To evaluate the Sysmex HISCL hs-cTnT assay's analytical performance.
• To compare its performance against the Roche hs-cTnT assay.
• To establish 99th-percentile upper reference limits (99% URLs) in a healthy population and assess the impact of age and estimated glomerular filtration rate (eGFR).

Main Methods:

• Assay verification included limits of blank/detection, precision, and functional sensitivity.
• Method comparison was performed using linear regression and Bland-Altman analysis between Sysmex HISCL and Roche Elecsys analyzers.
• 99% URLs were derived from a healthy cohort (n=1004), and the influence of age and eGFR on hs-cTnT levels was analyzed.

Main Results:

• The HISCL assay demonstrated low limits of detection (1.3 ng/L) and blank (1.9 ng/L), with good precision (CVs < 10% at 99% URLs).
• Excellent agreement was observed with the Roche assay (r=0.95), with minimal mean differences.
• The 99% URLs were established as 14.4 ng/L (overall), 17.0 ng/L (males), and 13.9 ng/L (females), with hs-cTnT levels increasing with age and decreasing eGFR.

Conclusions:

• The Sysmex HISCL hs-cTnT assay meets the criteria for a high-sensitivity assay.
• It demonstrates reliable performance and good agreement with a comparator assay.
• Established 99% URLs and observed age/eGFR effects are important considerations for clinical interpretation.