Background: The Pentra MS CRP hematology analyzer (hereinafter the Pentra analyzer) can simultaneously provide 5-part leukocyte differential and C-reactive protein (CRP). The aim of the study was to investigate the performance of CRP determination by the Pentra analyzer.
Methods: The precision, limit of quantitation (LoQ), carryover, linearity, stability, and comparability of the Pentra analyzer were determined. The Passing-Bablok regression analysis and the Bland-Altman graphs illustrated the correlation for CRP concentration analyzed by the Pentra analyzer and BN-II analyzer.
Results: The within-run precision of CRP determination by the Pentra analyzer had a CV < 2.0% in peripheral blood, which met the requirements of the instructions (CV ≤ 10%). The Pentra analyzer had a total CV of 5.35% and 5.52% at a CRP concentration of 4.1 and 80 mg/L, respectively. The LoQ value for the Pentra analyzer was 0.96 mg/L. The carryover was 0.57% for peripheral blood and 0.86% for plasma by the analyzer. The stability of CRP results was good, when the anticoagulation samples were stored at room temperature or 4°C within 48 hours (deviation < 5%). The linearity range for whole blood samples was 0 - 188.13 mg/L (r² = 0.9992). There was high correlation of the CRP results analyzed with the Pentra analyzer and BN II analyzer. The Passing-Bablok regression analysis and the Bland-Altman graphs showed the bias plot display excellent agreement between the two assays (the mean value for the Pentra 2.19 mg/L and the BN-II 2.35 mg/L, n = 101).
Conclusions: The results of CRP determination by the Pentra analyzer have the advantages of accuracy and reliability, and it is suitable for routine use in emergency laboratory and small to medium-size laboratories.