Evaluation of procalcitonin assay on the Abbott Architect i2000 SR® analyzer

Procalcitonin (PCT) is a useful biomarker for the diagnosis of bacterial infection. Its measurement is used routinely as a valuable tool for antibiotic treatment decision. The aim of this study is to assess the analytical performance of the new Architect Brahms PCT (R) reagents on the Abbott Architect i2000-SR (R) immuno-analyzer. The Architect PCT (R) assay was evaluated according to the modified SFBC protocol, in accordance with the NF EN ISO 15189 standard. Sixty two samples from patients hospitalized in Necker Hospital (Paris) have been tested with the evaluated method, and results were compared to those of the PCT Kryptor Brahms (R) method. Analytical performances tested complied with those announced by the manufacturer. Linear regression showed a strong correlation between the two methods (r > 0.99), despite a tendency for overestimation by the new method (y=1.10 x + 0.05). Bland-Altman plots confirmed this strong correlation by showing only two points outside the acceptable limits without clinical incidence, given the high PCT concentrations (over 10 ng/mL) in those samples. In conclusion, the new PCT assay on the Abbott Architect i2000-SR (R) shows excellent analytical performances, even at low concentrations. A slight positive bias compared to the Brahms Kryptor (R) was observed, but did not lead to inappropriate clinical decisions.