Analytical performances of a novel point-of-care procalcitonin assay

Anne Marie Dupuy; Anne Sophie Bargnoux; Aneta Andreeva; Charlie Zins; Nils Kuster; Stéphanie Badiou; Jean Paul Cristol

doi:10.1016/j.plabm.2019.e00145

Analytical performances of a novel point-of-care procalcitonin assay

Pract Lab Med. 2019 Oct 26:18:e00145. doi: 10.1016/j.plabm.2019.e00145. eCollection 2020 Jan.

Authors

Anne Marie Dupuy¹, Anne Sophie Bargnoux², Aneta Andreeva¹, Charlie Zins¹, Nils Kuster², Stéphanie Badiou², Jean Paul Cristol²

Affiliations

¹ Laboratoire de Biochimie et Hormonologie, CHU Montpellier, Univ Montpellier 1, Montpellier, F-34295, cédex 5, France.
² Laboratoire de Biochimie et Hormonologie, PhyMedExp, Université de Montpellier, INSERM, CNRS, CHU de Montpellier, France.

Abstract

Objectives: We report the analytical performances of a new point-of-care (POC) procalcitonin (PCT) fluorescence immunoassay that uses the AFIAS-6© system from Boditech and its concordance with results of the standard method Kryptor Compact plus from the central laboratory.

Design: and methods: Analytical performances including imprecision studies, limit of blank (LoB), limit of detection (LoD) and limit of quantification (LOQ) were determined. The method comparison was performed using plasma vs. whole blood for Kryptor CompactPlus© vs. AFIAS-6©, respectively.

Results: The total imprecision was far from the CV of 4.5% claimed by the manufacturer and close to 10%, for levels of PCT at 0.4 and 8.3 μg/L. The LoD of this novel PCT assay was found to close to the LoD provided by the manufacturer at 0.04 μg/L. The LOQ was higher than that claimed by the manufacturer (0.1 vs 0.002, respectively). The equation of linearity in the lower range was found to be y = 1.056x - 0.039 with r² = 0.993 with a mean recovery percentage of 86 ± 15%. Correlation studies showed a good correlation between PCT measurements using plasma on Kryptor system and on corresponding whole blood with POC reaching a bias of -0.04 in the range from 0.02 to 2 μg/L.

Conclusion: The novel PCT assay on AFIAS-6© is an acceptable POC alternative for the diagnosis and management of sepsis at EDs to improve the flow of patients, as results are consistent with those of the standard PCT Kryptor Compact Plus© assay, despite its higher imprecision.

Keywords: Clinical concordance; Correlation; PCT; Precision.