Comparative analysis of Access PCT and Elecsys BRAHMS PCT assays for procalcitonin measurements

Background: Procalcitonin (PCT) is a crucial biomarker for diagnosing sepsis and managing antibiotic therapy. This study evaluated the analytical performance and comparability of the Access PCT and Elecsys BRAHMS PCT assays. Methods: The precision, detection capability, linearity, and reference range of both assays were assessed. A comparative analysis included 182 patient samples categorized into four risk groups to compare the results between Access PCT and Elecsys BRAHMS PCT assays.Results: The Access PCT assay demonstrated precision within the manufacturer’s threshold, and its detection capabilities were verified. This assay exhibited excellent linearity and appropriate reference intervals. Comparative analysis indicated that the Access PCT assay reported higher overall PCT levels than the Elecsys BRAHMS assay, with high agreement between the assays (κ=0.941). However, the biases varied across different PCT concentration intervals.Conclusions: Both the Access PCT and Elecsys BRAHMS PCT assays performed robustly with notable concordance but varying biases at different concentration intervals. The observed biases require careful consideration in clinical decision-making, especially when adopting novel assay systems. Standardizing the calibration across different platforms is recommended to improve assay comparability.