A new sensitive automated assay for procalcitonin detection: LIAISON^® BRAHMS PCT^® II GEN

To assess the performance of LIAISON^® BRAHMS PCT^® II GEN (DiaSorin, Saluggia, Italy) in procalcitonin (PCT) determination by comparing it to the assay reference method B·R·A·H·M·S PCT KRYPTOR (Thermo Fisher Scientific Clinical Diagnostics, Hennigsdorf, Germany) and assessing its ability to discriminate between healthy subjects and patients with suspected infection.

Diagnostic performance was evaluated on: a) 193 selected samples covering the assay range, whose procalcitonin levels were already evaluated with the B·R·A·H·M·S PCT^® KRYPTOR; b) prospective samples: 150 apparently healthy specimens obtained from a blood bank, 161 hospitalized patients (not with specific pathologies), 243 apparently healthy children.

The comparison of LIAISON^® BRAHMS PCT^® II GEN to the reference method B·R·A·H·M·S PCT KRYPTOR yielded high correlation coefficients: slope of Deming fit equal to 1.04 (95% CI: 0.99-1.09) with an intercept equal to 0.05 (95% CI: -0.09 to 0.19) and a high concordance (98.4% (95% CI: 95.5-99.7%)) at the 0.5 ng/mL cut-off. Moreover, the results obtained using prospective samples showed: (i) no samples with PCT concentration >0.5 ng/mL (cut-off) for the apparently healthy adults (highest value=0.033 ng/mL, 95th percentile and 97.5th percentile <0.02 ng/mL); (ii) 2 samples >0.5 ng/mL for hospitalized patients (highest value=0.715 ng/mL, 95th percentile: 0.054 ng/mL; 97.5th percentile: 0.088 ng/mL); (iii) 3 samples >0.5 ng/mL for the healthy children population (highest value=0.713 ng/mL, 95th percentile: 0.155 ng/mL; 97.5th percentile: 0.275 ng/mL).

The fully automated LIAISON^® BRAHMS PCT^® II GEN agrees well with the reference method and is suitable for early diagnosis of sepsis, severe bacterial infection and guiding antibiotic therapy.