Evaluación analítica del inmunoanálisis Lumipulse® G BRAHMS PCT para la medida de procalcitonina

Introduction

Procalcitonin (PCT) is a useful biomarker for the management of patients with severe bacterial infection and sepsis. Different types of assays are currently available for its measurement. This study presents an evaluation of the analytical performance of the novel Lumipulse G BRAHMS PCT™ immunoassay on the Lumipulse 600II analyser.

Material and methods

This analytical evaluation included the calculation of the limit of blank, limit of detection, functional sensitivity, intra-assay and total imprecision, confirmation of linearity and the comparison with the ELECSYS BRAHMS PCT™ assay.

Results

Limit of blank, limit of detection and functional sensitivity were 0.0011 ng/mL, 0.0025 ng/mL, and 0.008 ng/mL, respectively. Intra-assay and total imprecision ranged from 0.78 to 2.16 and from 1.31 to 2.06, respectively, when control levels were used. The linearity was excellent (r=0.999) in the range of concentrations established by manufacturer. A highly significant agreement was found in the comparison between both assays (Lumipulse BRAHMS PCT = −0.016 + 1.006 * ELECSYS BRAHMS PCT). The mean bias was 0.2 ng/mL (95% CI: −0.906 to 0.430). When PCT levels were stratified according to the ranges normally used for their clinical interpretation, the agreement was very high (kappa index: 0.9874 (95% CI: 0.9696 to 1.0000).

Conclusion

The novel assay Lumipulse BRAHMS PCT, with CLEIA technology, appears to be acceptable for clinical use.