Comparison of Procalcitonin Assays on KRYPTOR and LIAISON XL Analyzers.

Our laboratory performs procalcitonin (PCT) assays on a Brahms KRYPTOR analyzer with the Brahms PCT sensitive Kryptor kit. In this study, we wanted to compare the assays obtained in this way with the ones performed on the LIAISON XL. From January to May 2017, 171 samples were analyzed, of which 65 from female patients (age: 22-98 years) and 106 from male patients (age: 16-97 years). The PCT determination was performed using the LIAISON XL and KRYPTOR analyzers, by chemiluminescence (Chemiluminescence immunoassay-CLIA) (LIAISON BRAHMS PCT II GEN) and immunofluorescence (Brahms PCT sensitive Kryptor) assay, respectively. For the LIAISON BRAHMS PCT II GEN, 52% of the results were placed between 0.0 and 0.5 ng/mL, 18% between 0.5 and 2.0 ng/mL, and 30% between 2.0 and 100 ng/mL; the mean was 4.09 ng/mL, the median 0.456 ng/mL, the maximum value 97.2 ng/mL, and the minimum value 0.02 ng/mL. For the Brahms PCT sensitive Kryptor, 55% of the results were positioned between 0.0 and 0.5 ng/mL, 21% between 0.5 and 2.0 ng/mL, and 24% between 2.0 and 100 ng/mL; the mean was 3.72 ng/mL, the median 0.39 ng/mL, the maximum value 103 ng/mL, and the minimum value 0.01 ng/mL. The mean of the results obtained with the two methods showed no significant differences (3.717 for Kryptor and 4.094 for LIAISON). PCT assay with Brahms reagents, both on the Kryptor and LIAISONXL platforms, offers excellent performance in terms of sensitivity and specificity.